DE102023202578A1 - Fluid machine - Google Patents

Abstract

The invention relates to a fluid machine (1), with a first fluid chamber (12) that is at least temporarily fluidically connected to a first fluid connection (17) of the fluid machine (1) and a second fluid chamber (13) that is at least temporarily fluidically connected to a second fluid connection (18) of the fluid machine (1), and with a fluid conveying element (3) that is mounted so as to be rotatable about an axis of rotation (5), which at least partially delimits the first fluid chamber (12) and/or the second fluid chamber (13) and is provided and designed to convey a fluid from the first fluid chamber (12) in the direction of the second fluid chamber (13), and with a control element (19) that slides against the fluid conveying element (3) and in which at least one control recess (22) is formed that is open in the direction of the fluid conveying element (3), from which in the circumferential direction with respect to the axis of rotation (5) an edge (31) of the control recess (22) that is open in the direction of the fluid conveying element (3) extends. penetrating pilot control recess (28). It is provided that a flow cross-sectional area of the pilot control recess (28) has different rates of change in different pilot control recess regions (32, 33, 34) which follow one another in the circumferential direction.

Description

The invention relates to a fluid machine, with a first fluid chamber that is at least temporarily fluidically connected to a first fluid connection of the fluid machine and a second fluid chamber that is at least temporarily fluidically connected to a second fluid connection of the fluid machine, and with a fluid conveying element that is mounted so as to be rotatable about an axis of rotation, which at least partially delimits the first fluid chamber and/or the second fluid chamber and is provided and designed to convey a fluid from the first fluid chamber in the direction of the second fluid chamber, and with a control element that slides against the fluid conveying element and in which at least one control recess is formed that is open in the direction of the fluid conveying element, from which a pilot control recess that is open in the direction of the fluid conveying element and extends through an edge of the control recess extends in the circumferential direction with respect to the axis of rotation.

The state of the art includes, for example, the publication EN 10 2014 103 959 A1 This describes a motor-pump unit with a multi-part housing, which comprises a reversible internal gear machine and an electric motor with a rotor and a stator, which is coupled to the internal gear machine via a shaft rotatably mounted in the housing. The shaft extends with one shaft end away from the internal gear machine axially through the rotor carried by the shaft. A first connection channel and a second connection channel open into a working chamber of the internal gear machine and are connected via check valves arranged in the housing to a leakage channel loop, which is fluidly connected to at least one leakage channel fluidly connected to the working chamber and which has a leakage shaft channel extending axially through the shaft and a leakage rotor channel fluidly connected thereto, extending axially through the rotor and/or a leakage gap channel formed between the rotor and the stator, which is fluidly connected to the leakage shaft channel.

It is an object of the invention to propose a fluid machine which has advantages over known fluid machines, in particular enables an optimized pressure build-up or pressure reduction in the fluid machine.

This is achieved according to the invention with a fluid machine having the features of claim 1. It is provided that a flow cross-sectional area of the pilot control recess has different rates of change in different pilot control recess regions that follow one another in the circumferential direction.

Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims. It is pointed out that the embodiments explained in the description are not restrictive; rather, any variations of the features disclosed in the description, the claims and the figures can be implemented.

The fluid machine represents a fluid conveying device and is used to convey a fluid, for example a liquid or a gas. The fluid machine can basically be designed in any way, provided it has the rotatably mounted fluid conveying element on which the control element slides. In the context of this description, the design of the fluid machine as a gear fluid machine is discussed, for example as an internal gear fluid machine or as an external gear fluid machine. However, other embodiments of the fluid machine are also generally feasible. Purely by way of example, reference is made to a rotary piston fluid machine, for example a rotary vane fluid machine or a rotary piston fluid machine, as well as an axial piston fluid machine.

In any case, a rotatably mounted fluid conveying element serves to convey fluid from a first fluid chamber into a second fluid chamber or vice versa. The control element slidingly resting on the fluid conveying element serves to seal the first fluid chamber and/or the second fluid chamber. For example, the fluid conveying element and the control element jointly delimit at least one of the fluid chambers or both fluid chambers, at least in some areas. Of course, there can also be several control elements, which in this case preferably slide on opposite sides of the fluid conveying element, in particular in the axial direction with respect to the axis of rotation of the fluid conveying element. In this case, the control elements delimit the first fluid chamber and/or the second fluid chamber on opposite sides in the axial direction, whereas the fluid conveying element delimits the first fluid chamber and/or the second fluid chamber in the radial direction, in particular inwards or outwards.

The control recess is formed in the control element and is open in the direction of the fluid conveying element. As far as the control recess, at least one control recess or the at least one control recess is mentioned in this description, the Designs are always equivalent to one another and transferable to one another. Of course, only one control recess can be produced in the control element, but preferably there are several control recesses. In this case, what has been said for the control recess applies to at least some of the control recesses, preferably to all control recesses.

The control recess is designed in the control element in such a way that it is at least temporarily open in the direction of one of the fluid chambers or at least temporarily in flow connection with one of the fluid chambers. With the help of the control recess, a pressure build-up or pressure reduction occurring in the fluid machine, for example in one of the fluid chambers, can be controlled or adjusted in a targeted manner. In particular, with the help of the control recess, an at least partially uniform pressure distribution within one of the fluid chambers is additionally or alternatively achieved.

In order to be able to adjust the pressure build-up or pressure reduction even better, the pilot control recess extends from the control recess. The pilot control recess extends from the control recess in the circumferential direction, namely with respect to the axis of rotation of the fluid conveying element. It also penetrates the edge of the control recess, which is designed in the control element and delimits the control recess, in particular in the radial direction and/or in the circumferential direction. In other words, the pilot control recess opens into the control recess. The control recess and the pilot control recess are preferably produced by milling and/or embossing. For example, the control recess is first completely produced, in particular with a continuous edge. Only then is the pilot control recess produced in the control element, with the edge of the control recess being partially interrupted.

In order to achieve a particularly good effect of the pilot control recess, the flow cross-sectional area of the pilot control recess changes in the circumferential direction. The flow cross-sectional area is the area of a flow cross-section of the pilot control recess, which is present in section over the entire pilot control recess. The flow cross-section extends to an orifice opening, under the formation of which the pilot control recess passes through a side of the control element facing the fluid conveying element. In particular, the orifice opening is located in a sealing surface of the control element, with which the control element slides and thus seals against the fluid conveying element at least temporarily.

The pilot control recess is divided into several pilot control recess areas which follow one another in the circumferential direction. The pilot control recess areas are in particular directly adjacent to one another. There can be any number of pilot control recess areas, for example at least two pilot control recess areas, at least three pilot control recess areas or at least four pilot control recess areas. At least in immediately consecutive pilot control recess areas, the flow cross-sectional area of the pilot control recess has different rates of change. This means that in immediately adjacent pilot control recess areas there are different rates of change, whereas the rates of change in spaced-apart pilot control recess areas can be the same. Preferably, the rates of change have at least the same sign, so that the flow cross-sectional area changes in one direction, for example in the circumferential direction, in the same direction, i.e. it either becomes larger or smaller.

Preferably, the respective rate of change in the pilot control recess areas is constant or at least almost constant across the respective pilot control recess area. This means that the rate of change of the flow cross-sectional area only changes at a transition between the different pilot control recess areas and otherwise remains constant. Of course, it can be provided that this only applies to one or more of the pilot control recess areas, whereas the respective rate of change changes across at least one or more other pilot control recess areas. Thus, overall, it can be provided that the rate of change of the flow cross-sectional area is consistently constant across at least one of the pilot control recess areas, whereas it changes at least in some areas, in particular changes continuously, across at least one other of the pilot control recess areas. If the rate of change changes across the respective pilot control recess area, a constant or at least a continuous change in the rate of change is preferably provided in order to achieve a uniform progression of the flow cross-sectional area across the pilot control recess. The rate of change is preferably understood to be an absolute value of the rate of change, i.e. the sign-adjusted rate of change.

With the described design of the fluid machine, the pressure build-up or pressure reduction occurring in the fluid machine can be adjusted particularly precisely. With the control recesses that have been used up to now, a very abrupt pressure build-up or pressure reduction occurs, particularly at very low or very high speeds, especially in conjunction with high pressures. This is avoided by the described design of the pilot control recess, which has a positive influence on the service life of the fluid machine and/or the noise behavior of the fluid machine.

Depending on the direction of rotation of the fluid machine, one of the fluid chambers serves as a suction chamber and the other of the fluid chambers as a pressure chamber. If the fluid machine is designed as a pump or is operated as a pump, fluid is supplied to the respective suction chamber, which the fluid machine pumps towards the pressure chamber or into the pressure chamber. The suction chamber can accordingly also be referred to as the inlet chamber and the pressure chamber as the outlet chamber; the crucial point is that the fluid is always pumped from the inlet chamber towards the outlet chamber while the fluid machine is operating. The pressure in the inlet chamber is always lower than the pressure in the outlet chamber when the pump is operating. Of course, however, the pressure in the inlet chamber can already be (significantly) higher than ambient pressure. For example, the fluid machine is used to pump pressurized fluid from the inlet chamber towards the outlet chamber.

If, however, the fluid machine is in the form of a motor or is operated as a motor, fluid is supplied to the pressure chamber, which enters the suction chamber, causing the gears to rotate. In this case, the pressure chamber is the inlet chamber and the suction chamber is the outlet chamber; the pressure in the inlet chamber is higher than the pressure in the outlet chamber. This description does not specifically address the operation of the fluid machine as a motor, but rather the fluid machine, its structure and its function are explained for operation as a pump. Of course, it can also be used as a motor and the explanations are analogously applicable to such a design of the fluid machine or such a use.

Basically, it should be noted that in this description the suction chamber can also be referred to as a low-pressure chamber and the pressure chamber as a high-pressure chamber. Analogously, the suction side of the fluid machine corresponds to a low-pressure side and the pressure side to a high-pressure side. The terms "low pressure" and "high pressure" are not to be understood as a restriction to a specific pressure level; rather, the pressure in the high-pressure chamber or on the high-pressure side is simply higher, relatively speaking, than the pressure in the low-pressure chamber or on the low-pressure side.

A further development of the invention provides that the pilot control recess immediately adjacent to the control recess has a smaller flow cross-sectional area and/or a smaller depth than the control recess immediately adjacent to the pilot control recess. If the control recess and the pilot control recess are therefore considered as a recess as a whole, this recess has a sudden change in its flow cross-sectional area or its depth at the transition between the control recess and the pilot control recess. More precisely, the flow cross-sectional area or the depth becomes smaller at the transition from the control recess to the pilot control recess. For example, the reduction in the flow cross-sectional area is brought about solely by the reduction in depth. Preferably, however, the flow cross-sectional area also decreases apart from the reduction in depth or even without a change in depth, in particular by reducing a distance between pilot control recess walls which delimit the pilot control recess on opposite sides.

For example, the pilot control recess immediately adjacent to the control recess has a flow cross-sectional area which is at most 30%, at most 20% or at most 10% of the flow cross-sectional area of the control recess immediately adjacent to the pilot control recess. However, the flow cross-sectional area is particularly preferably smaller, for example it is at most 5%, at most 2.5% or at most 1% of the flow cross-sectional area of the control recess immediately adjacent to the pilot control recess. Additionally or alternatively - as already explained - the depth of the pilot control recess immediately adjacent to the control recess is smaller than the depth of the control recess immediately adjacent to the pilot control recess, for example it is at most 60%, at most 50% or at most 40% of the same. However, it is preferably even smaller and is, for example, at most 40%, at most 20% or at most 10% of the depth of the control recess immediately adjacent to the pilot control recess. With the described design of the fluid machine The advantages mentioned are achieved in a structurally simple manner, in particular the optimized pressure build-up or pressure reduction is implemented.

A further development of the invention provides that the pilot control recess is delimited by a pilot control recess base and by opposite pilot control recess walls. The pilot control recess base delimits the pilot control recess in the axial direction, i.e. in the direction facing away from the fluid conveying element. The pilot control recess walls, however, delimit the pilot control recess in a direction perpendicular to this, in particular in the radial direction inwards and outwards and preferably also in the circumferential direction, namely at least on one side of the pilot control recess facing away from the control recess. The pilot control recess passes through the aforementioned sealing surface of the control element to form the mouth opening, which is made on the side of the pilot control recess opposite the pilot control recess base. The pilot control recess walls form an edge of this mouth opening, which is preferably continuous away from the control recess. The edge of the pilot control recess is therefore only interrupted at the point where it joins the control recess. This also achieves the aforementioned advantages.

A further development of the invention provides that in at least one of the pilot control recess areas, the pilot control recess walls run parallel to one another. This means that the pilot control recess walls have a constant distance from one another across the pilot control recess area. If the pilot control recess walls are curved, one of the pilot control recess walls runs, for example, on a shell of a first circular cylinder and a second of the pilot control recess walls runs on the shell of a second circular cylinder, which preferably has the same diameter as the first circular cylinder, but is arranged offset from it. The parallel course of the pilot control recess walls in the pilot control recess area results in a comparatively low rate of change in the flow cross-sectional area of this pilot control recess area. A variation in the rates of change of the pilot control recess areas is thus achieved in a structurally simple manner.

A further development of the invention provides that in at least one of the pilot recess areas, the pilot recess base runs parallel to a mouth opening, via which the pilot recess is open in the direction of the fluid conveying element, so that the depth of the pilot recess is constant over an extension of the pilot recess area. This means in particular that the pilot recess base runs parallel to the sealing surface already mentioned, which penetrates the pilot recess to create the mouth opening in the direction of the fluid conveying element. With the help of the parallel arrangement of the pilot recess base with respect to the mouth opening or the sealing surface, a constant depth of the pilot recess in the pilot recess area is achieved. In this way, too, a low rate of change of the flow cross-sectional area in the respective pilot recess area can be achieved quite easily.

A further development of the invention provides that in at least one of the pilot control recess areas there is a rate of change other than zero due to a change in a distance between the pilot control recess walls over an extension of the pilot control recess area and/or due to a change in the depth of the pilot control recess over an extension of the pilot control recess area. The rate of change other than zero is to be understood as meaning that the flow cross-sectional area of the pilot control recess changes over the corresponding pilot control recess area, i.e. it either becomes larger or smaller. This can be achieved by different measures. On the one hand, it is possible to change the distance between the pilot control recess walls or the depth of the pilot control recess, i.e. the distance of the pilot control recess base from the mouth opening or the sealing surface.

It can be provided that only the distance between the pilot recess walls changes, whereas the depth of the pilot recess remains constant across the pilot recess area. Conversely, it can be provided that the distance between the pilot recess walls remains constant, but the depth of the pilot recess changes across the pilot recess area. Last but not least, both the distance between the pilot recess walls and the depth of the pilot recess can change in the pilot recess area or across it. The change in the distance and the change in the depth preferably take place in such a way that they cause a change in the feedthrough cross-sectional area in the same direction. If the change in the distance between the pilot recess walls walls, the change in depth is also selected to cause such an increase. The opposite is true for the decrease in the flow cross-sectional area. The distance is changed, for example, by the pilot recess walls running straight towards one another so that the distance continuously decreases, namely at a constant rate of change. However, it can also be provided that at least one of the pilot recess walls or both pilot recess walls are curved, namely such that their distance from one another changes. The pilot recess base can also be straight or curved to change the depth. For example, a convex or concave course of the pilot recess walls and/or the pilot recess base is realized. The advantages already mentioned can be easily achieved in the manner described.

A further development of the invention provides that in a first of the pilot control recess areas adjacent to the control recess there is a first rate of change of the flow cross-sectional area and in a second of the pilot control recess areas adjacent to the first pilot control recess area there is a second rate of change of the flow cross-sectional area, the second rate of change being greater than the first rate of change. Starting from the control recess, the rate of change of the flow cross-sectional area of the pilot control recess, in particular its absolute value, should initially be greater and then decrease. This means that the flow cross-sectional area of the pilot control recess initially changes less in the first pilot control recess area starting from the control recess and then more strongly in the second pilot control recess area. This allows an extremely targeted adjustment of the pressure build-up and/or pressure reduction during operation of the fluid machine.

A further development of the invention provides that one of the pilot control recess areas is bordered on both sides by another of the pilot control recess areas, wherein the rate of change in the pilot control recess area is greater than in the other pilot control recess areas, in particular by a factor of at least 5, at least 10 or at least 15. In total, there are therefore at least three pilot control recess areas, namely the pilot control recess area and the two other pilot control recess areas. The other pilot control recess areas are arranged on opposite sides of the pilot control recess area and thus accommodate it between them. The other pilot control recess areas are directly adjacent to the pilot control recess area, i.e. they extend directly from it.

In the other pilot control recess areas, the rate of change of the flow cross-sectional area is smaller than the rate of change in the pilot control recess area. The rates of change in the other pilot control recess areas can be identical or different from one another. Preferably, the rate of change in the pilot control recess area is significantly greater than the rates of change or each of the rates of change in the other pilot control recess areas, preferably by one of the factors mentioned. This achieves the advantages already mentioned.

A further development of the invention provides that the change rates in the further pilot control recess areas are identical or differ from one another by at most 50%, at most 25% or at most 10%. The change rate in a first of the further pilot control recess areas therefore corresponds to the change rate in a second of the further pilot control recess areas or differs from these by at most one of the stated values. The deviation can be upwards or downwards, for example a larger change rate is greater than a smaller change rate by at most one of the stated values. Conversely, the smaller of the change rates is smaller than the larger change rate by at most one of the stated values. Overall, this results in a design of the fluid machine in which there is a comparatively large change rate in the pilot control recess area, whereas the change rates in the further pilot control recess areas enclosing the pilot control recess area are identical or at least almost identical. This allows the fluid to flow into the pilot recess area with little loss, so that the pressure build-up or pressure reduction of the fluid is optimized during operation of the fluid machine.

A further development of the invention provides that the control recess is at least temporarily fluidically connected to one of the fluid connections. For example, it is provided that the fluid connection is connected to one of the fluid chambers via the control recess. The fluidic connection between the control recess and the fluid connection is not only indirectly via the fluid chamber, but the control recess is fluidically provided between the fluid chamber and the fluid connection. Accordingly, inflow into and outflow from the fluid chamber in such a design takes place via the control recess. In a gear fluid machine, in particular an internal gear fluid machine, the fluid thus flows in and out in the axial direction. This implements efficient flow guidance within the fluid machine.

A further development of the invention provides that at least one further pilot control recess extends from the control recess in the circumferential direction with respect to the axis of rotation, said further pilot control recess being open in the direction of the fluid conveying element and extending through an edge of the control recess, wherein a flow cross-sectional area of the at least one further pilot control recess has different rates of change in different pilot control recess regions that follow one another in the circumferential direction. In addition to the pilot control recess, there is therefore the further pilot control recess, which also extends from the control recess and extends through its edge.

Preferably, the pilot control recess and the further pilot control recess extend from the control recess in the same direction, in particular in the circumferential direction. The pilot control recess and the further pilot control recess are arranged on the same side of the control recess and extend from it, in particular in the circumferential direction. The further pilot control recess is designed essentially analogously to the pilot control recess, so reference is made to the relevant explanations. The change rates that exist in the pilot control recess areas of the further pilot control recess preferably correspond to the change rates of the pilot control recess areas in the pilot control recess; however, they can also be different from these. With the help of the multiple pilot control recesses, i.e. the pilot control recess and the at least one further pilot control recess, the pressure build-up or pressure reduction in the fluid machine can be controlled in a particularly targeted manner.

A further development of the invention provides that the fluid machine is a gear fluid machine and the fluid conveying element is a first gear with a first toothing and the rotation axis is a first rotation axis, wherein in addition to the first gear there is a second gear mounted so as to be rotatable about a second rotation axis and with a second toothing that meshes with the first toothing. The gear fluid machine therefore has two gears, namely the first gear and the second gear. The gear fluid machine can in turn basically be designed in any way, in particular it is an external gear fluid machine or an internal gear fluid machine.

In the case of the external gear fluid machine, both gears have external teeth that mesh with one another in an engagement area. If the fluid machine is an internal gear fluid machine, the first gear has external teeth and the second gear has internal teeth, or vice versa. In this case, the first gear can also be referred to as a pinion and the second gear as a ring gear. The teeth of the two gears mesh with one another in areas viewed in the circumferential direction, i.e. they mesh with one another in areas, namely in an engagement area. Regardless of the design of the fluid machine, the two gears are intended for fluid conveyance and are therefore designed in such a way that they work together during a rotary movement to convey the fluid and mesh with one another or mesh with one another. This means that a rotary movement of the first gear is transmitted directly to the second gear and, conversely, a rotary movement of the second gear is transmitted directly to the first gear.

Both the first gear and the second gear are preferably arranged in a machine housing of the fluid machine and are rotatably mounted therein. The first gear is rotatably mounted about the first axis of rotation, whereas the second gear is rotatably mounted about the second axis of rotation. In the internal gear fluid machine, the first gear is arranged in the second gear when viewed in cross section, i.e. in a cutting plane perpendicular to the axes of rotation, in such a way that the teeth, in particular external teeth, of the first gear mesh with the teeth, in particular internal teeth, of the second gear in the engagement area or are in engagement with them. In the context of this description, reference is mainly made to the design of the fluid machine as an internal gear fluid machine by way of example. The described design of the control element can, however, be used in any fluid machine and in particular in any gear fluid machine, in particular also for the external gear fluid machine. The statements can therefore always be transferred analogously to a gear fluid machine designed as an external gear fluid machine.

The engagement area, for example, is fixed to the housing and does not rotate with the first gear or the second gear. In the engagement area, a tooth of one of the gears engages in a tooth gap of the other of the gears. The tooth gap is limited in the circumferential direction by teeth of the respective gear. For example, a tooth of the first gear engages in a tooth gap of the second gear or, conversely, a tooth of the second gear engages in a tooth gap of the first gear.

The two gears of the fluid machine are arranged between housing walls of the aforementioned machine housing of the fluid machine. For example, the gears are mounted on and/or in the machine housing, in particular on the housing walls. One of the housing walls is therefore located on a first side of the gears and a second of the housing walls is located on a second side of the gears opposite the first side in the axial direction, so that the housing walls accommodate the gears between them in the axial direction. For example, a gap remaining between the housing walls and the gears is dimensioned so small that the housing walls ensure adequate sealing of the fluid space or the fluid chambers.

However, it is particularly preferred that an - optional - sealing disk is arranged in the axial direction with respect to the first axis of rotation next to the first gear and the second gear, i.e. in particular between one of the housing walls and the gears, which sealingly rests against the first gear and the second gear during operation of the fluid machine. For example, viewed in the axial direction, the sealing disk is only present on one side of the first gear and the second gear. However, it is preferably provided that - again viewed in the axial direction - such a sealing disk is arranged on both sides of the two gears. In the context of this description, the particularly advantageous case of multiple sealing disks is explained. It goes without saying, however, that the corresponding embodiments can also be used for a design of the fluid machine in which only a single sealing disk is part of the fluid machine.

The sealing disk is preferably forced in the axial direction towards the gears, for example by applying pressure, i.e. by applying a pressurized fluid, so that it lies sealingly against the gears. If there are several sealing disks, these are arranged on both sides of the gears in the axial direction. One of the sealing disks is therefore on a first side of the gears and a second of the sealing disks is on a second side of the gears opposite the first side in the axial direction, so that the sealing disks hold the gears between them in the axial direction. The sealing disks are preferably forced towards one another in the axial direction and thus each in the direction of the gears, for example by applying pressure, i.e. by applying the pressurized fluid, so that the sealing disks lie sealingly against the gears on opposite sides. The fluid machine is therefore axially compensated or gap-compensated in the axial direction. This achieves a particularly high level of efficiency of the fluid machine.

The sealing disk is preferably in the form of the control element already described. In other words, the control element is designed as a sealing disk and is therefore located axially next to the gears of the fluid machine. According to the above statements, it is particularly preferred to use several sealing disks and correspondingly several control elements. These are arranged on opposite sides of the gears and lie against one another in a sealing manner, in particular with their respective sealing surface. The pressure build-up or pressure reduction can be influenced particularly advantageously with the help of the control recess and the pilot control recess.

A further development of the invention provides that the pilot control recess and the at least one further pilot control recess are arranged at a distance from one another in the radial direction, in particular the pilot control recess is arranged in the radial direction with respect to the first axis of rotation in overlap with teeth of the first gearing and the further pilot control recess is arranged in the radial direction with respect to the second axis of rotation in overlap with teeth of the second gearing. Such a configuration enables a particularly targeted adjustment of the pressure build-up and the pressure reduction, in particular in the spaces between the teeth of the gearing or gears. This is achieved by the arrangement of the pilot control recess and the further pilot control recess offset in the radial direction. Particularly preferably, the pilot control recess and the at least one further pilot control recess are additionally arranged in overlap at least in some areas in the circumferential direction. This means that a straight line perpendicular to one of the axes of rotation intersects both the pilot control recess and the at least one further pilot control recess. It can also be provided that the pilot recess is at least temporarily in contact with the interdental spaces of the first gearing and the further pilot recess is at least temporarily in overlap with the tooth spaces of the second toothing, so that fluid can flow between them, for example from the respective pilot recess into the respective tooth spaces or vice versa. This in turn achieves the aforementioned advantages.

A further development of the invention provides that in a first region, seen in the circumferential direction, the first toothing and the second toothing engage with one another and in a second region, tooth tips of the first toothing and the second toothing rest against one another in a sealing manner in order to divide a fluid space present between the first gear and the second gear into a first fluid chamber and a second fluid chamber, or that between the first gear and the second gear, away from the first region, a filler piece is arranged which rests on the one hand on the first toothing and on the other hand on the second toothing in order to divide the fluid space present between the first gear and the second gear into the first fluid chamber and the second fluid chamber.

In the engagement area, the first toothing and the second toothing work together in a sealing manner. On the other side of the engagement area, i.e. preferably on the side diametrically opposite the engagement area with respect to the first axis of rotation and/or the second axis of rotation, a filler piece is arranged, for example. The filler piece is located between the first gear and the second gear, or in other words between the external toothing of the first gear and the internal toothing of the second gear. The filler piece is thus arranged in a fluid space which is delimited in the radially inward direction by the first gear and in the radially outward direction by the second gear, in each case with respect to the first axis of rotation and the second axis of rotation. The filler piece rests on the one hand on the first toothing and on the other hand on the second toothing. More precisely, the filler piece rests in a sealing manner on tooth tips of the first toothing and in a sealing manner on tooth tips of the second toothing in order to divide the fluid space into a first fluid chamber and a second fluid chamber. Each of the two fluid chambers is therefore limited in the circumferential direction on the one hand by the filler piece and on the other hand by the tight meshing of the first toothing and the second toothing in the engagement area.

The filler piece is preferably designed in several parts and therefore has several segments. The segments of the filler piece are arranged next to one another in the radial direction, so that a first segment is arranged on the side of a second segment facing the first gear and vice versa, the second segment is arranged on the side of the first segment facing the second gear. The first segment lies sealingly against the first gear or its external teeth and the second segment lies sealingly against the second gear or the internal teeth of the second gear. The two segments can preferably be displaced against one another in the radial direction. Of course, however, a one-piece filler piece can also be present. In this case, the internal gear fluid machine is uncompensated in the radial direction.

Particularly preferably, a gap between the segments is subjected to fluid pressure during operation of the fluid machine in such a way that the first segment is pushed in the direction of the first gear and the second segment in the direction of the second gear, so that the segments are in sealing contact with the respective gear or the tooth tips of the corresponding gearing. The fluid machine is thus radially compensated or gap-compensated in the radial direction. Each of the segments can be further divided into segments. For example, the first segment is one-piece or consists of at least two segments and/or the second segment is one-piece or consists of at least two segments. These segments of the filler piece are also preferably mounted so that they can be displaced relative to one another, i.e. can be displaced independently of one another. This achieves particularly effective gap compensation.

As an alternative to the filler piece, on the other side of the engagement area, i.e. again preferably on the side diametrically opposite the engagement area with respect to the first axis of rotation and/or the second axis of rotation, at least one tooth tip of the internal toothing and one tooth tip of the external toothing are in sealing contact with one another, in particular with a tip circle surface of the respective tooth delimited by the respective tip circle of the corresponding toothing. In other words, a tip circle surface of the tooth tip of the internal toothing is delimited by the tip circle of the internal toothing and a tip circle surface of the tooth tip of the external toothing is in sealing contact with one another. The tip circle surface of the internal toothing and the tip circle surface of the external toothing are now in sealing contact with one another. This in turn divides the fluid space into the first fluid chamber and the second fluid chamber. Each of the two fluid chambers is separated in the circumferential direction on the one hand by the tip circle surfaces lying close together and on the other hand by the tight meshing of the external toothing and the internal toothing in the The engagement area is limited. Such a design of the fluid machine can also be referred to as a gear ring fluid machine.

A further development of the invention provides that the pilot control recess and the further pilot control recess are arranged on opposite sides of the filler piece, viewed in the radial direction. This makes it easy to achieve the overlap of the respective pilot control recess with the teeth or interdental spaces of the respective toothing. In particular, the pilot control recess and the further pilot control recess each overlap with the filler piece in the circumferential direction, in particular completely. This means that the pilot control recess is in an angular range with respect to the first axis of rotation or extends over it, which is completely encompassed by the filler piece. In addition, the further pilot control recess is in an angular range with respect to the second axis of rotation or extends over it, which is completely encompassed by the filler piece in the circumferential direction. Once again, the advantages described are achieved in this way.

A further development of the invention provides that the control recess has two recess extensions, each of which extends from a base recess of the control recess, wherein the recess extensions are arranged on opposite sides of the filler piece when viewed in the radial direction and the pilot control recess extends from a first of the recess extensions and the further pilot control recess extends from a second of the recess extensions. The recess extensions together with the base recess form the control recess; the control recess is therefore made up of the base recess and the two recess extensions, in particular exclusively. When viewed in section, the recess extensions are only connected to one another via the base recess, and apart from the base recess they are spaced apart from one another throughout.

The recess extensions are arranged on opposite sides of the filler piece, so that the first recess extension overlaps with the teeth or tooth spaces of the first toothing and the second recess extension overlaps with the teeth or tooth spaces of the second toothing. For example, the recess extensions have an extension in the radial direction which corresponds to at least 50%, at least 70% or at least 90% of a difference between a tip circle and a root circle or vice versa of the respective toothing. This means that the respective pilot recess partially, completely or at least almost completely overlaps the teeth or tooth spaces of the respective toothing in the radial direction. One of the pilot recesses extends from the recess extensions, namely the pilot recess from the first recess extension and the further pilot recess from the second recess extension.

For example, it is provided that, viewed in the radial direction, the pilot control recess is arranged to overlap with a base circle of the first gearing and/or the further pilot control recess is arranged to overlap with a base circle of the second gearing. However, it can also be provided that, viewed in the radial direction, the pilot control recess is arranged to overlap with the base circle of the first gearing, whereas the further pilot control recess is located away from the base circle of the second gearing, i.e. is not in overlap. Conversely, it can be provided that, viewed in the radial direction, the pilot control recess is arranged away from the base circle of the first gearing and the further pilot control recess is arranged to overlap with the base circle of the second gearing. The advantages explained are achieved by means of such a design of the fluid machine.

A further development of the invention provides that in the radial direction between the pilot control recesses there is a sealing surface on the control element, which sealingly rests against an end face of the filler piece. The sealing surface of the control element has already been mentioned. The sealing surface is preferably present at least in some areas between the recess extensions, in particular it extends between the recess extensions through to the base recess. With the sealing surface, the control element lies slidingly or sealingly on the end face of the filler piece and - preferably - also on the end faces of the gears. With the help of the control element or the control elements, at least one of the fluid chambers or both fluid chambers are closed in the axial direction. This enables the fluid machine to be highly efficient.

A further development of the invention provides that the sealing surface is penetrated by a fluid channel which is arranged in overlap with a gap between segments of the filler piece. The gap arranged between the segments has already been mentioned. This is at least temporarily subjected to the pressurized fluid so that the segments in the radial direction away from each other and are pushed against the gear teeth. The gap is pressurized via the fluid channel, which is created for this purpose in the control element, namely in such a way that it passes through the sealing surface. The sealing surface lies sealingly against the segments away from the fluid channel, so that a fluid connection is created between the fluid channel and the gap. This design of the fluid machine enables efficient gap compensation.

A further development of the invention provides that on the side of the control recess facing away from the pilot control recess in the circumferential direction, a control recess extension extends from the control recess, which has a smaller flow cross-sectional area and/or a smaller depth immediately adjacent to the control recess than the control recess immediately adjacent to the control recess extension. The control recess extension is similar to the pilot control recess with regard to the smaller flow cross-sectional area and/or the smaller depth. The control recess extension is preferably arranged in such a way that it is arranged in radial direction in overlap with teeth and tooth spaces of both toothings, namely in particular in the engagement area.

For example, the control recess extension extends radially outwards to a tip circle of the first gear and/or to a root circle of the second gear. In the radial direction inwards it extends only over a part of the difference between the tip circle diameter and the root circle diameter of the respective gear, i.e. it only partially overlaps the teeth or tooth spaces of the respective gear in the radial direction, in particular to a maximum of 50%, a maximum of 40% or a maximum of 30%. It particularly preferably extends in the circumferential direction to a point at which the gears engage with each other to the maximum. The control recess extension also serves to set an advantageous behavior of the pressure build-up or pressure reduction. It can be provided that the control recess extension is designed analogously to the pilot control recess and in this respect a flow cross-sectional area of the control recess extension has different rates of change in different control recess extension regions that follow one another in the circumferential direction. The corresponding embodiments for the pilot control recess are in this case analogously applicable to the control recess extension.

The features and combinations of features described in the description, in particular the features and combinations of features described in the following description of the figures and/or shown in the figures, can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the invention. Thus, embodiments are also to be regarded as being encompassed by the invention that are not explicitly shown or explained in the description and/or the figures, but which emerge from the embodiments explained or can be derived from them.

• 1 eine schematische Darstellung einer Fluidmaschine, welche als Innenzahnradfluidmaschine ausgestaltet ist und ein neben zwei Zahnrädern angeordnetes Steuerelement aufweist,
• 2 eine schematische Darstellung des Steuerelements,
• 3 eine schematische Detaildarstellung eines Bereichs des Steuerelements, sowie
• 4 eine schematische Schnittdarstellung eines Bereichs des Steuerelements.

The invention is explained in more detail below using the initial examples shown in the drawing, without limiting the invention. In the drawing:

• 1 a schematic representation of a fluid machine which is designed as an internal gear fluid machine and has a control element arranged next to two gears,
• 2 a schematic representation of the control element,
• 3 a detailed schematic representation of an area of the control element, as well as
• 4 a schematic cross-sectional view of a portion of the control element.

The 1 shows a schematic representation of a fluid machine 1, which here is a gear fluid machine, in particular an internal gear fluid machine, and has a machine housing 2 in which a fluid conveying element designed as a first gear 3 and a second gear 4 are rotatably mounted. The first gear 3 is rotatably mounted in the machine housing 2 about a first axis of rotation 5 and the second gear 4 about a second axis of rotation 6. It can be seen that the first axis of rotation 5 and the second axis of rotation 6 are arranged parallel and spaced from one another, so that the first gear 3 and the second gear 4 have different axes of rotation. The first gear 3 has a first toothing 7 designed as an external toothing and the second gear 4 has a second toothing 8 designed as an internal toothing, which mesh with one another in an engagement region 9, i.e. are in engagement with one another.

The first gear 3 and the second gear 4 together delimit a fluid space 10. The first gear 3 delimits the fluid space 10 in the radial direction inwards and the second gear 4 in the radial direction outwards. The fluid space 10 is divided into a first fluid chamber 12 in the circumferential direction by the meshing of the gears 3 and 4 on the one hand and a filler piece 11 on the other hand. and a second fluid chamber 13. Depending on the direction of rotation of the fluid machine 1, one of the fluid chambers 12 and 13 is the suction chamber and another of the fluid chambers 12 and 13 is the pressure chamber. The filler piece 11 is designed in several parts and has several segments 14 and 15. Between the segments 14 and 15 there is a gap 16 which can be filled with pressurized fluid. This fluid loading forces the segments 14 and 15 in the direction of the respective gear 3 or 4. This provides radial compensation for the fluid machine 1. Each of the fluid chambers 12 and 13 is fluidly connected to one of several fluid connections 17 and 18, namely the first fluid chamber 12 with the first fluid connection 17 and the second fluid chamber 13 with the second fluid connection 18. The fluid connections 17 and 18 are indicated here purely by way of example.

A control element 19 slides in the axial direction on the first gear 3, i.e. the fluid conveying element, and on the second gear 4, which can also be referred to as a further fluid conveying element. For this purpose, the control element 19 has a sealing surface 20 which faces the gears 3 and 4. The sealing surface 20 rests both on the gears 3 and 4 and on the filler piece 11. The fluid machine 1 preferably has several control elements 19, which in this case rest on opposite sides of the gears 3 and 4 and the filler piece 11. Only the control element 19 will be discussed below. However, the explanations are of course applicable to each of the several control elements 19.

The control element 19 can also be referred to as a sealing disk. It ultimately serves to tightly seal at least one area of the fluid chamber 10 in the axial direction. The control element 19 is rotatably mounted on the machine housing 2 by means of a bearing bolt (not shown here). For this purpose, the bearing bolt passes through a bearing bolt receptacle 21 of the control element 19, which is present, for example, as a circular through-hole. A control recess 22 is produced in the control element 19, which here is present as a depression open in the direction of the gears 3 and 4. The control recess 22 has a continuous control recess base 23, which runs uninterrupted over the entire control recess 22, i.e. continuously delimits the control recess 22 in the direction facing away from the gears 3 and 4.

The control recess 22 is divided into several areas, namely a base recess 24, from which two recess extensions 25 and 26 extend. The recess extensions 25 and 26 are arranged spaced apart from one another in the radial direction, with the sealing surface 20 extending between the recess extensions 25 and 26 and running as far as the base recess 24. The sealing surface 20 is penetrated between the recess extensions 25 and 26 by a fluid channel 27, which is fluidically connected to the gap 16 and via which the gap 16 is at least temporarily subjected to a pressurized fluid. The recess extensions 25 and 26 run in the radial direction on opposite sides of the filler piece 11, namely the recess extension 25 radially on the inside and the recess extension 26 radially on the outside.

A pilot control recess 28 extends from the control recess 22, which can also be referred to as the first pilot control recess. Additionally or alternatively, a further pilot control recess 29 extends from the control recess 22, which is also referred to as the second pilot control recess. The pilot control recesses 28 and 29 extend from the recess extensions 25 and 26, namely the first pilot control recess 28 extends from the recess extension 25 and the second pilot control recess 99 extends from the recess extension 26. Both pilot control recesses 28 and 29 extend from the control recess 22 in the circumferential direction in the same direction. Viewed in the radial direction, they overlap with the gears 7 and 8. Via the pilot control recesses 28 and 29, a pressure build-up or a pressure reduction in the fluid machine 1 can be influenced and adjusted as desired.

Optionally, a control recess extension 30 extends from the control recess 22, namely in the circumferential direction on the side of the control recess 22 facing away from the pilot control recesses 28 and 29. The control recess extension 30 has a smaller flow cross-sectional area and/or a smaller depth on its side facing the control recess 22 than the control recess 22 on its side facing the toothed control recess 30.

The 2 shows a schematic detailed representation of the control element 19. It can be seen that the pilot control recesses 28 and 29 each pass through a control recess edge 31 delimiting the control recess 22. They each have a smaller flow cross-sectional area and/or a smaller depth immediately adjacent to the control recess 22 than the control recess 22 immediately adjacent to to the respective pilot control recess 28 or 29. It can also be seen that at least one of the pilot control recesses 28 and 29, in particular both pilot control recesses 28 and 29, each have several pilot control recess areas 32, 33 and 34 or 35, 36 and 37. Only the first pilot control recess 28 and thus the pilot control recess areas 32, 33 and 34 are discussed below. However, the explanations can - optionally - be transferred to the second pilot control recess 29 and thus the pilot control recess areas 34, 36 and 37.

The pilot control recess 28 is delimited on the side facing away from the gears 3 and 4 by a pilot control recess base 38. In the radial direction and - optionally - in the circumferential direction, it is delimited on opposite sides by spaced pilot control recess walls 39 and 40. A flow cross-sectional area of the pilot control recess 28 now has different rates of change in the different pilot control recess areas 32, 33 and 34. In this case, it is particularly provided that the rate of change in the first pilot control recess area 32 is smaller than that in the second pilot control recess area 33. The rate of change in the third pilot control recess area 34 is also smaller than that in the second pilot control recess area 33. The rates of change in the first pilot control recess area 32 and the third pilot control recess area 34 are particularly preferably identical or at least almost identical. For example, the rate of change in the first pilot recess region 32 and the third pilot recess region 34 is zero or at least almost zero. This is achieved by a parallel course of the pilot recess walls 39 and 40 and a constant depth of the pilot recess 28 in these regions.

The 3 shows a schematic detailed representation of an area of the control element 19, namely in particular in the area of the first pilot recess 28. It can be seen that in the first pilot recess area 32 the pilot recess walls 39 and 40 run parallel to one another, whereas in the second pilot recess area 33 they run towards one another in the direction facing away from the control recess 22, so that the flow cross-sectional area of the pilot recess 28 decreases in these areas at a certain rate of change. In the third pilot recess area 34, however, the walls 39 and 40 are again constantly or at least almost constantly spaced apart from one another, namely up to an outlet area 41 of the pilot recess 28.

The 4 shows a sectional view through the control element 19 in the area of the first pilot control recess 28. It can be seen that a depth of the pilot control recess 28 is consistently significantly less than a depth of the control recess 22. In particular, the depth of the pilot control recess 28 immediately adjacent to the control recess 22 is at most 50% as large as the depth of the control recess 22 immediately adjacent to the pilot control recess 28. Accordingly, at a transition between the control recess 22 and the pilot control recess 28, there is a step 42 between the control recess base 23 and the pilot control recess base 38.

It can be seen that the depth of the pilot control recess 28 remains constant over the first pilot control recess region 32. In the second pilot control recess region 33, however, the depth decreases in the direction away from the control recess 22. In the third pilot control recess region 34, the depth of the pilot control recess 28 is either constant or it continues to decrease, but at a smaller rate of change than in the second pilot control recess region 33. The run-out region 41 merely serves to close off the pilot control recess 28. It has significantly smaller dimensions in the circumferential direction than any of the other pilot control recess regions 32, 33 and 34, for example its dimensions in this direction are at most 20%, at most 10% or at most 5% of the dimensions of the third pilot control recess region 34.

With the described design of the fluid machine 1 and in particular of the control element 19, the pressure build-up or pressure reduction in the fluid machine 1 can be influenced in a targeted manner. This is done in particular in such a way that during operation of the fluid machine 1, the fluid forces acting on its components are reduced compared to a conventional design of the control recess 22 and the pilot control recesses 28 and 29, so that an improvement in the service life of the fluid machine 1 and acoustic advantages result.

LIST OF REFERENCE SYMBOLS

1

Fluid machine

2

Machine housing

3

1. Gear

4

2. Gear

5

1. Rotation axis

6

2. Rotation axis

7

1. Gearing

8

2. Gearing

9

Intervention area

10

Fluid space

11

Filler piece

12

1. Fluid chamber

13

2. Fluid chamber

14

segment

15

segment

16

gap

17

1. Fluid connection

18

2. Fluid connection

19

Control

20

Sealing surface

21

Bearing bolt holder

22

Tax exemption

23

Reason for tax exemption

24

Base recess

25

Recess extension

26

Recess extension

27

Fluid channel

28

1. VAT exemption

29

2. Input tax exemption

30

Tax relief extension

31

Control recess edge

32

1. Pre-tax exemption area

33

2. Pre-tax exemption area

34

3. Pre-tax exemption area

35

1. Pre-tax exemption area

36

2. Pre-tax exemption area

37

3. Pre-tax exemption area

38

Reason for VAT exemption

39

Pilot control recess wall

40

Pilot control recess wall

41

Run-off area

42

Level

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102014103959 A1 [0002]

Claims (15)

Fluid machine (1), with a first fluid chamber (12) which is at least temporarily fluidically connected to a first fluid connection (17) of the fluid machine (1) and a second fluid chamber (13) which is at least temporarily fluidically connected to a second fluid connection (18) of the fluid machine (1), and with a fluid conveying element (3) which is mounted so as to be rotatable about an axis of rotation (5), which at least partially delimits the first fluid chamber (12) and/or the second fluid chamber (13) and is provided and designed to convey a fluid from the first fluid chamber (12) in the direction of the second fluid chamber (13), and with a control element (19) which slides against the fluid conveying element (3) and in which at least one control recess (22) is formed which is open in the direction of the fluid conveying element (3), from which in the circumferential direction with respect to the axis of rotation (5) there extends a recess which is open in the direction of the fluid conveying element (3) and which passes through an edge (31) of the control recess (22). Pilot control recess (28), characterized in that a flow cross-sectional area of the pilot control recess (28) has different rates of change in different pilot control recess regions (32, 33, 34) which follow one another in the circumferential direction. Fluid machine according to Claim 1 , characterized in that the pilot control recess (28) immediately adjacent to the control recess (22) has a smaller flow cross-sectional area and/or a smaller depth than the control recess (22) immediately adjacent to the pilot control recess (28). Fluid machine according to one of the preceding claims, characterized in that the pilot control recess (28) is delimited by a pilot control recess base (38) and by opposite pilot control recess walls (39, 40). Fluid machine according to one of the preceding claims, characterized in that in at least one of the pilot control recess areas (32, 33, 34) the pilot control recess walls (39, 40) run parallel to one another. Fluid machine according to one of the preceding claims, characterized in that in at least one of the pilot control recess regions (32, 33, 34) the pilot control recess base (38) runs parallel to an opening via which the pilot control recess (28) is open in the direction of the fluid conveying element (3), so that the depth of the pilot control recess (28) is constant over an extension of the pilot control recess region (32, 34). Fluid machine according to one of the preceding claims, characterized in that in at least one of the pilot control recess regions (32, 33, 34) there is a rate of change other than zero due to a change in a distance between the pilot control recess walls (39, 40) over an extension of the pilot control recess region (33) and/or due to a change in the depth of the pilot control recess (28) over an extension of the pilot control recess region (33). Fluid machine according to one of the preceding claims, characterized in that in a first of the pilot control recess regions (32, 33, 34) adjoining the control recess (22) there is a first rate of change of the flow cross-sectional area and in a second of the pilot control recess regions (32, 33, 34) adjoining the first pilot control recess region (32) there is a second rate of change of the flow cross-sectional area, wherein the second rate of change is greater than the first rate of change. Fluid machine according to one of the preceding claims, characterized in that a further pilot control recess region (32, 33, 34) adjoins one of the pilot control recess regions (32, 33, 34) on both sides, wherein the rate of change in the pilot control recess region (33) is greater than in the further pilot control recess regions (32, 34). Fluid machine according to one of the preceding claims, characterized in that the rate of change in the further pilot control recess areas (33, 34) are identical or differ from one another by at most 50%, at most 25% or at most 10%. Fluid machine according to one of the preceding claims, characterized in that the control recess (22) is at least temporarily fluidically connected to one of the fluid connections (17, 18). Fluid machine according to one of the preceding claims, characterized in that at least one further pilot control recess (29) extends from the control recess (22) in the circumferential direction with respect to the axis of rotation (5), said further pilot control recess (29) being open in the direction of the fluid conveying element (3) and passing through an edge (31) of the control recess (22), wherein a flow cross-sectional area of the at least one further pilot control recess (29) can be configured in different circumferential directions successive pilot control recess areas (35, 36, 37) have different rates of change. Fluid machine according to one of the preceding claims, characterized in that the fluid machine (1) is a gear fluid machine and the fluid conveying element (3) is a first gear (3) with a first toothing (7) and the axis of rotation (5) is a first axis of rotation (5), wherein in addition to the first gear (3) there is a second gear (4) rotatably mounted about a second axis of rotation (6) with a second toothing (8) meshing with the first toothing (7). Fluid machine according to one of the preceding claims, characterized in that the pilot control recess (28) and the at least one further pilot control recess (29) are arranged at a distance from one another in the radial direction. Fluid machine according to one of the preceding claims, characterized in that in a first region, seen in the circumferential direction, the first toothing (7) and the second toothing (8) engage with one another and in a second region, tooth tips of the first toothing (7) and the second toothing (8) bear against one another in a sealing manner in order to divide a fluid space (10) present between the first gear (3) and the second gear (4) into a first fluid chamber (12) and a second fluid chamber (13), or that between the first gear (3) and the second gear (4) away from the first region, a filler piece (11) is arranged which bears on the one hand against the first toothing (7) and on the other hand against the second toothing (8) in order to divide the fluid space (10) present between the first gear (3) and the second gear (4) into the first fluid chamber (12) and the second fluid chamber (13). Fluid machine according to one of the preceding claims, characterized in that the pilot control recess (28) and the further pilot control recess (29) are arranged on opposite sides of the filler piece (11) as seen in the radial direction.

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