DE102015214147A1 - Pneumatically adjustable CVT transmission - Google Patents

Abstract

The present invention relates to a CVT transmission comprising a conical disk pair (2) with at least one axially movable conical disk (21); an adjusting device (5) for adjusting a position of the axially movable conical disk (21); and a control unit (6) arranged to actuate the adjusting device (5) to change the position of the axially movable conical disk (21) the control unit (6) comprises a pneumatic pressure box (50) for adjusting the axially movable conical disk (21) by means of a pneumatic force.

Description

State of the art

The present invention relates to a pneumatically variable CVT transmission (continuously variable transmission) especially for small vehicles such as two-wheelers, tricycles, quads or snowmobiles and an internal combustion engine and a vehicle.

CVT transmissions are known from the prior art in various configurations. Due to the continuously variable transmission suitable ratios can be achieved in vehicles in each case in comparison with gears with fixed gears. A particular application of such CVT transmissions are small vehicles, such as two-wheelers, tricycles (so-called Tucktucks), snowmobiles, quads or scooters. In such CVT transmissions, centrifugal governors are often used to adjust a position of a belt on a cone pulley pair. Depending on the speed, centrifugal weights of the centrifugal governor thereby shift their radial position, whereby an axial distance between two conical disks is changed, thereby changing a transmission ratio. A disadvantage of such arrangements, however, is that no actively controlled or regulated intervention in the transmission ratio of the CVT transmission is possible. In this case, it would be desirable to have a simple way of controlled intervention in a transmission ratio of CVT transmissions, which can be used in particular for small vehicles.

Disclosure of the invention

The CVT transmission according to the invention with the features of claim 1, on the other hand, has the advantage that an emission behavior and a fuel consumption of a vehicle can be significantly improved, since a controlled intervention in a transmission ratio of a CVT transmission is possible. This also significantly better performance, especially in driving dynamics with respect to an acceleration from a standstill and with respect to an acceleration of a moving vehicle can be achieved. According to the invention, an adjusting device for adjusting a position of an axially movable conical disk is provided for this purpose. The adjusting device is a pneumatic adjusting device, which adjusts the axially movable conical disk by means of pneumatic force. Thus, the CVT transmission can each be operated at an optimum operating point. Here, the adjusting device comprises a pneumatic pressure cell which is connected to the axially movable conical disk in order to adjust it by means of pneumatic force. This allows a simple and compact design can be realized.

The dependent claims show preferred developments of the invention.

Preferably, the CVT transmission includes a vacuum source connected to the pressure cell. The vacuum source provides the necessary to adjust the axially movable conical disk pneumatic force. The vacuum source is particularly preferably a suction pipe of an internal combustion engine.

More preferably, the pressure cell has such a structure that in the pressure box, a movable piston is arranged. The movable piston is preferably mechanically connected to the axially movable conical disk. This can be achieved by pressurizing the piston movement of the piston and thus movement of the axially movable conical disk. The piston can be pressurized with negative pressure or negative pressure.

The pressure cell is further preferably connected to a bearing unit, wherein the axially movable conical disk is mounted on the bearing unit. As a result, a particularly compact design of the CVT transmission is realized.

Further, the CVT transmission preferably includes centrifugal weights, which are arranged on the axially movable conical disk. Here, the centrifugal weights depending on a speed of the axially movable cone pulley already about a corresponding speed matching gear ratio ready, in which case by means of the adjusting device according to the invention a fine adjustment of the translation can be made. Thus, in particular short switching times for changing the translation can be realized. This results in a very simple structure.

According to a further preferred embodiment of the invention, the piston in the pressure box can be acted upon only on one side with an overpressure or underpressure.

Furthermore, the present invention relates to an internal combustion engine comprising a CVT transmission according to the invention. The internal combustion engine preferably comprises at least one cylinder and a cylinder-leading intake manifold, wherein the intake manifold is connected to the pneumatic actuator of the CVT transmission to provide the pneumatic force for adjustment of the CVT transmission. Preferably, the suction tube is connected to the pneumatic accumulator. Through the use of the suction tube thus a negative pressure for pneumatic adjustment of the CVT transmission can be used. This is particularly advantageous because the vacuum is anyway present in internal combustion engines with intake manifold and can be used in addition to setting a gear ratio of a CVT transmission.

More preferably, the adjusting device is designed as a retrofit kit.

Furthermore, the present invention relates to a vehicle comprising a CVT transmission according to the invention and / or an internal combustion engine according to the invention.

The vehicle preferably has a vehicle frame, in particular a pipe or pipe assembly, which is designed as a pneumatic accumulator. For this purpose, a hollow frame is provided in which an overpressure or a negative pressure can be used as a pneumatic accumulator for the provision of the pneumatic force for adjusting the CVT transmission. This is particularly advantageous when using two-wheeled or three-wheeled vehicles, which usually have such a hollow frame. As a result, no further components for the pneumatic accumulator are necessary, but only a few sections of hollow tubes or the like. Must be pneumatically sealed to serve as a pneumatic accumulator.

The vehicle according to the invention is preferably a small vehicle, in particular a two-wheeler or a tricycle or a quad or a snowmobile or a scooter or the like.

drawing

Hereinafter, embodiments of the invention will be described in detail with reference to the accompanying drawings. In the drawing is:

1 FIG. 2 a schematic representation of a construction of a CVT transmission for a small vehicle according to a first exemplary embodiment of the invention, FIG.

2 a sectional view of the CVT transmission of 1 .

3 a schematic representation of a control valve of the CVT transmission of 1 , and

4 a schematic representation of an alternative control valve for a CVT transmission according to the invention.

Preferred embodiments of the invention

The following is with reference to 1 to 3 a CVT transmission 1 , ie a continuously variable, continuously variable transmission, according to a preferred embodiment of the invention described in detail.

How out 1 can be seen includes the CVT transmission 1 a cone pulley pair 2 with a fixed cone pulley 20 and an axially movable cone pulley 21 , As output element 13 serves a second cone pulley pair. The two conical disk pairs are in a known manner via a belt 12 , In particular a belt, connected together.

The first cone pulley pair 2 is on a crankshaft 11 an internal combustion engine 10 arranged. The crankshaft 11 is with the stationary cone pulley 20 firmly connected.

The CVT transmission 1 also includes centrifugal elements 3 , which on the axially movable cone pulley 21 are arranged. In this embodiment, the centrifugal elements 3 Balls. Alternatively, solid cylinders or hollow cylinders or the like can be used.

Furthermore, includes the CVT transmission 1 a support element 4 , which is connected to the axially movable cone pulley 21 is arranged. The centrifugal elements 3 are between the support element 4 and the axially movable cone pulley 21 arranged. On the axially movable cone pulley 21 is at the to the support element 4 directed side a corresponding tread 22 provided along which the centrifugal elements move.

For adjusting an axial position of the axially movable conical disk 21 is now an adjusting device 5 intended. The adjusting device 5 is provided as a pneumatic actuator and includes a pneumatic pressure box 50 , which with the axially movable cone pulley 21 connected is. The pressure cell 50 includes a piston arranged in the pressure box 51 and a pole 52 , which from the pressure box 50 led out. The pole 52 is with a storage unit 56 connected, on which the axially movable conical disk 21 is stored. The storage unit 56 includes an inner sleeve 53 , an outer sleeve 54 and a bearing disposed between the inner sleeve and the outer sleeve 55 ,

How out 2 it can be seen, is the inner sleeve 53 through the stationary cone pulley 20 passed. Furthermore, on the support element 4 a cylindrical sleeve area 41 provided on which the inner sleeve 53 slidably disposed. The inner sleeve 53 is fixed to the axially movable cone pulley 21 connected.

The warehouse 55 interrupts a transmission of a rotation of the crankshaft 11 on the adjusting device 5 , The rotation of the crankshaft 11 However, this is about the sleeve area 41 and the inner sleeve 53 on the axially movable cone pulley 21 transfer.

The piston 51 in the pressure cell subdivides the inner area of the pressure cell into two areas, namely a negative pressure area 15 and a normal pressure range 25 ,

Like from the 1 and 2 it can be seen is the pressure box 50 with a suction pipe 9 the internal combustion engine 10 connected. The suction tube 9 in this case represents a vacuum source for the adjusting device 5 ready.

The suction tube 9 is over a first line 16 with a vacuum reservoir 7 connected. The vacuum reservoir 7 is then over a second line 17 with the pressure box 50 connected. In the first line 16 is an automatically closing check valve 18 provide. In the second line 17 is a controllable control valve 8th intended. The control valve 8th is doing by means of a control unit 6 driven.

The crankshaft 11 is on a housing 14 stored.

The control valve 8th is in detail in 3 shown. In this embodiment, the control valve 8th a 3/3-way valve, where the negative pressure range 15 the pressure box 50 on the one hand with the vacuum reservoir 7 and on the other hand with an environment 19 can be connected. The third position of the 3/3-way valve is the fully closed position, which in 3 is shown.

The piston 51 is only unilaterally acted upon by negative pressure.

Depending on the position of the 3/3-way valve can thus the piston 51 in the direction of arrow A (s. 2 ) or in the opposite direction. Alternatively, for a provision, for example, one in the negative pressure range 15 the pressure box 50 arranged spring element can be used.

According to the invention thus in the internal combustion engine 10 in the intake manifold 9 existing negative pressure as pneumatic energy to adjust a ratio of the CVT transmission 1 used. A pressure level in the intake manifold 9 is dependent on a throttle position and a speed of the internal combustion engine. During operation of the internal combustion engine can thus always a vacuum supply of the vacuum accumulator 7 be ensured and thus a simple and safe adjustment of the axially movable conical disk 21 be achieved by pneumatic force.

The pressure cell 50 is preferably at an axial end of the crankshaft 11 arranged. This allows a very compact and mechanically simple construction can be realized.

Furthermore, by adjusting the gear ratio by means of negative pressure and a size and weight of the centrifugal elements 3 be reduced by about 20%. In this way, in particular a weight reduction of the CVT transmission can be achieved in comparison with the prior art. By realizing the adjustment of the CVT transmission by means of the pressure box 50 Furthermore, retrofitting of existing CVT transmissions can also be made possible.

The vacuum reservoir 7 is particularly preferably arranged in a hollow frame of a vehicle. For this purpose, no additional space for the vacuum reservoir in the vehicle is necessary.

Furthermore, in the described first embodiment, the adjusting device 5 on a primary side of the CVT transmission, ie, arranged on the input side. Alternatively, it is also possible that the invention on a secondary side, ie, on the output element 13 , is used.

The inventive possibility of an exact setting of a gear ratio can thus achieve an increase in efficiency of the CVT transmission, which has a positive effect on exhaust emissions and fuel consumption.

4 shows an alternative embodiment of the control valve, which in this embodiment two 2/2-way valves 80 . 81 having. One of the 2/2-way valves is between the vacuum reservoir 7 and the pressure box 50 arranged and the other of the two 2/2-way valves is between the pressure box 50 and the environment 19 arranged.

The present invention, as described in the embodiments, is particularly applicable to small vehicles, e.g. Used on two-wheelers or tricycles or quads or snowmobiles or the like.

Claims (15)

CVT transmission, comprising A pair of conical disks ( 2 ) with at least one axially movable conical disk ( 21 ); An adjusting device ( 5 ) for adjusting a position of the axially movable conical disk ( 21 ), and - a control unit ( 6 ), which is set up, the adjusting device ( 5 ) to adjust the position of the axially movable cone pulley ( 21 ), - the adjusting device ( 5 ) a pneumatic pressure box ( 50 ) to the axially movable cone pulley ( 21 ) Adjust by means of a pneumatic force. A CVT transmission according to claim 1, further comprising a negative pressure source connected to the pressure box ( 50 ) connected is. CVT transmission according to claim 2, characterized in that the vacuum source a suction pipe ( 9 ) is an internal combustion engine. CVT transmission according to one of the preceding claims, characterized in that the pressure box ( 50 ) a piston ( 51 ), which is arranged in the pressure cell. CVT transmission according to one of the preceding claims, characterized in that the pressure box ( 50 ) with a storage unit ( 56 ), wherein the axially movable conical disk ( 21 ) at the storage unit ( 56 ) is stored. CVT transmission according to claim 5, characterized in that the piston ( 51 ) of the pressure box via a rod ( 52 ) with the storage unit ( 56 ) connected is. CVT transmission according to one of the preceding claims, further comprising centrifugal elements ( 3 ), which on the axially movable conical disk ( 21 ) are arranged. CVT transmission according to one of claims 4 to 7, characterized in that the piston ( 51 ) in the pressure box ( 50 ) can be acted upon only on one side with the negative pressure. CVT transmission according to one of the preceding claims, characterized in that the adjusting device is provided as a retrofit kit.  Internal combustion engine comprising a CVT transmission according to one of the preceding claims. Internal combustion engine according to claim 10, comprising a suction pipe leading to a cylinder of the internal combustion engine ( 9 ), wherein the suction tube ( 9 ) with the adjusting device ( 5 ) of the CVT transmission is connected to a pneumatic force for axial displacement of the axially movable conical disk ( 21 ). Internal combustion engine according to claim 10 or 11, characterized in that a vacuum reservoir ( 7 ) between the suction pipe ( 9 ) and the adjusting device ( 5 ) is arranged.  Vehicle comprising a CVT transmission according to one of claims 1 to 9 and / or an internal combustion engine according to one of claims 10 to 12.  Vehicle according to claim 13, further comprising a vehicle frame, in particular a tube, which is designed as a vacuum reservoir. Vehicle according to claim 13 or 14, characterized in that the vehicle is a small vehicle, in particular a two-wheeler or a tricycle or a quad or a snowmobile.

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