JPH075263Y2 - Vane pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a vane pump for supplying a pressurized fluid to a power steering device or the like.

<Prior Art> In a conventional vane pump, an opening of a hollow chamber of a pump housing is closed by an end cover. A chamfer is formed on the outer peripheral end surface of the end cover, a snap ring with a circular cross section is fitted in a groove with a semicircular cross section provided on the pump housing, and the snap ring is pressed into contact with the chamfered part of the end cover. The cover is fixed to the pump housing. Further, the snap ring is provided with a notch portion for attachment.

<Problems to be solved by the device> Due to the structure described above, if excessive pressure such as surge pressure is applied to the end cover from inside the pump, the strain due to stress concentration in the notch of the snap ring increases and If the notch is located near the screw hole into which the pump position fixing bracket provided on the pump housing is screwed,
A crack will occur at the end of the pump housing. Therefore, increasing the pressure inside the pump has a limit in terms of strength.

<Means for Solving the Problems> The present invention has been made to solve the above-mentioned problems, and the snap ring is arranged so that the notch portion of the snap ring is located near the mounting position of the bracket. The plate-shaped reinforcing member is fixed between the end of the opening of the pump housing and the bracket by a bolt and presses the end of the opening of the pump housing.

<Operation> When the rotating shaft is driven by the engine, etc., the rotor rotates, whereby the working oil is sucked into the pump chamber via the suction port, and the discharge fluid is discharged from the discharge port to be delivered to the controlled device. To be done. The oil sent to the controlled device returns to the reservoir tank after causing the controlled device to perform a predetermined operation. Then, during the rotation of the vane pump, the pressure generated in the pump housing is applied to the end cover and the snap ring of the opening. When excessive pressure such as surge pressure occurs in the pump housing, stress concentrates on the notch part of the snap ring, and excessive pressure acts on the pump housing from the notch part, but it is reinforced against this pressure. The pressing force by the member is applied.

<Embodiment> An embodiment of the present invention will be described below with reference to the drawings. First
In FIG. 2 and FIG. 2, a bottomed hollow chamber 11 is formed in the pump housing 10, and this hollow chamber 11 is the pump housing 10.
It has an opening at one end. The opening of the hollow chamber 11 of the pump housing 10 is closed by an end cover 12. A chamfer is formed on the outer peripheral end surface of the end cover 12, a groove having a semi-circular cross section provided in the pump housing 10 has a circular cross section, and has a notch for assembling. Insert the end cover 12
The end cover 12 is fixed to the pump housing 10 by pressing the snap ring 13 at the chamfered portion. A screw hole 46 for a fixing bolt 37 for mounting a bracket 44 for fixing to the engine is formed at the end of the opening of the pump housing 10. A disk-shaped reinforcing member 36 for pressing the end of the pump housing 10 together with the bracket 44 is screwed into the screw hole 46 by the fixing bolt 37, and the reinforcing member 36 has a size matching the wall surface of the hollow chamber 11. It has become. Further, the snap ring 13 is assembled so that the notch portion is located near the screw hole 46.

In the hollow chamber 11 surrounded by the pump housing 10 and the end cover 12, a cam ring 14, a first side plate 15 that contacts one side surface of the cam ring 14, and a cam ring 14
A second side plate 16 that is in contact with the other side surface is housed. The inner circumference of the first side plate 15 is fitted to the central boss portion of the pump housing 10. A wave washer 17 is inserted between the second side plate 16 and the end cover 12 in a resilient state.
The cam ring 14, the first side plate 15, and the second side plate 16 are in contact with each other by the repulsive force of 17.

An inner peripheral cam surface 20 having an oval cross section is formed on the inner periphery of the cam ring 14, and a rotor 22 in which a plurality of vanes 21 slidably contacting the inner peripheral cam surface 20 are slidably inserted in the radial direction is provided. It is stored in the cam ring 14. The rotor 22 is the vane 21
Slits 19 into which are inserted are formed at equal angular intervals, and a back pressure chamber 39 is formed inside a radius of each slit 19. The rotor 22 is spline-engaged with one end of a rotary shaft 24, and the rotary shaft 24 is rotatably supported by a bearing metal 23 fitted in a bearing hole of the pump housing 10.

A plurality of pump chambers defined by the vanes 21 are formed between the inner peripheral cam surface 20 of the cam ring 14 and the outer peripheral surface of the rotor 22, and the respective pump chambers change in volume due to the rotation of the rotor 22. Suction ports 27 and 28 are provided on the surfaces of the first side plate 15 and the second side plate 16 that are in contact with the rotor 22 so as to correspond to the pump chambers that perform the expansion process, and to the pump chambers that perform the compression process. Discharge ports 25 and 26 are formed respectively. The suction ports 27, 28 are opened to an annular groove 29 provided in the hollow chamber 11 so as to surround the cam ring 14, and the annular groove 29 is connected to a bypass passage 34 for guiding a bypass flow bypassed by the flow control valve 33. , And communicates with the reservoir 32. A plug 31 having a curved concave surface portion is inserted at the terminal end of the bypass passage 34 to form a bent portion that directs the bypass flow to the outer peripheral surface of the cam ring. The discharge port 26 is opened to a discharge chamber 30 formed on the back surface side of the first side plate 15, and the discharge chamber 30 communicates with a valve hole 33 of a flow control valve 45 via a passage not shown. The discharge port 25 is opened to a working chamber 38 formed between the second side plate 16 and the end cover 12. Also, the side plates 15 and 16 are formed with a plurality of arc-shaped pressure grooves 40 and 41 at positions corresponding to the back pressure chamber 39, and the pressure grooves 40 and 41 are the second pressure grooves.
It communicates with the working chamber 38 via a pressure introducing passage 42 formed in the side plate 16.

Further, the pump housing 10 is formed with an escape passage 35 which connects the oil reservoir 43 defined by the outer end of the bearing metal 23 and the seal member 18 with the bypass passage 34.

Next, the operation will be described based on the configuration described above. When the rotary shaft 24 is rotated by the engine, the rotor 22 rotates, whereby the working fluid is sucked into the pump chamber via the suction ports 27 and 28, and the volume of the pump chamber is compressed, so that the discharge port 25. The fluid is discharged into the discharge chamber 30 via The discharged working fluid is sent from the discharge chamber 30 to the controlled device such as the power steering device via the flow control valve 45, and operates the controlled device. Furthermore, the working fluid is the working chamber.
It is guided to the back pressure chamber 39 through 38, the pressure introduction passage 42, and the pressure grooves 40 and 41, and serves to press one end of the vane 21 against the inner peripheral cam surface 20.

If excessive pressure is applied from inside the pump, the end cover 12
A pressure is applied to the snap ring 13 from the chamfered portion of the end cover 12. Assemble the notch of the snap ring 13 so that it is located near the screw hole 46 in the opening of the pump housing 10, and attach the reinforcing member 36 with the fixing bolt 37 to the screw hole in the opening of the pump housing 10.
Since it is fixed so that it presses around 46, stress concentrates in the notch of the snap ring 13 and the snap ring 13
The pressing force of the reinforcing member 36 acts against the excessive pressure acting on the opening of the pump housing 10 from the cutout portion of the pump housing 10, and a crack is generated at the end portion of the pump housing 10 at the position of the cutout portion of the snap ring 13. It can be prevented from occurring.

<Effect of the Invention> As described above, in the present invention, a plate-shaped reinforcing member that is fixed by a bolt between the end of the opening of the pump housing and the bracket and presses the end of the opening of the pump housing. Since it is arranged, the pressure resistance of the end of the opening of the pump housing can be increased, and the notch of the snap ring is located near the end of the opening of the pump housing to which the bracket is fixed. Even if excessive pressure such as surge pressure is applied to the end cover from the inside of the pump, the reinforcing member acts against the excessive pressure that acts on the pump housing from the snap ring notch. Therefore, it is possible to prevent cracks from occurring at the end of the pump housing at the notch of the snap ring, and to improve the pressure resistance of the pump. Can be large.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a side view of a vane pump, and FIG. 2 is a sectional view taken along line II-II of FIG. 10 …… Pump housing, 12 …… End cover, 13 ……
Snap ring, 14 …… Cam ring, 15 …… First side plate, 16 …… Second side plate, 22 …… Rotor,
24 …… Rotary shaft, 32 …… Reservoir, 36 …… Reinforcement member, 37 ・ ・ ・
… Fixing bolt.

Claims (1)

[Scope of utility model registration request] 1. A pump housing having a hollow chamber having an opening formed at one end, and a pump component including a cam ring, a rotor, a vane, a side plate, a rotary shaft and the like housed in the hollow chamber of the pump housing. An end cover that closes the opening of the pump housing, a snap ring that has a notch that is fitted into a groove provided in the inner periphery of the opening of the pump housing to fix the end cover, and an opening of the pump housing. In a vane pump including a bracket fixed to an end of a portion by a bolt, the snap ring is assembled to the pump housing such that a cutout portion of the snap ring is located near a mounting position of the bracket, and the pump housing The bolt between the end of the opening and the bracket. Vane pump is fixed, characterized in that provided with reinforcing members of a plate shape for pressing an end portion of the opening portion of the pump housing Te.