WO2017016731A1

WO2017016731A1 - Pneumatically adjustable continuously variable transmission

Info

Publication number: WO2017016731A1
Application number: PCT/EP2016/063028
Authority: WO
Inventors: Oliver Gerundt; Ianislav Krastev; Daniel Schwartz; Ingo Drewe; Rudolf Eydam; Ralf Diekmann; Carolin Breitinger; Mykhaylo Klymenko
Original assignee: Robert Bosch Gmbh
Priority date: 2015-07-27
Filing date: 2016-06-08
Publication date: 2017-02-02
Also published as: TW201708746A; DE102015214150A1

Abstract

The invention relates to a continuously variable transmission (CVT) comprising: a V-pulley (2) that includes at least one axially movable cone pulley (21); an adjusting device (5) for adjusting a position of the axially movable cone pulley (21); and a control unit (6) designed to actuate the adjusting device (5) in order to change the position of the axially movable cone pulley (21). The adjusting device (5) is a pneumatic adjusting device (5) that moves the axially movable cone pulley (21) using pneumatic force, and the adjusting device (5) has a double-acting adjusting element (51) such that the double-acting actuating element (51) can be moved into first and second axial directions (X-X).

Description

description

title

Pneumatically adjustable CVT transmission

State of the art

The present invention relates to a pneumatically adjustable CVT transmission (continuously variable transmission), in particular for small vehicles such as

Bikes, tricycles, quads or snowmobiles, as well as an internal combustion engine and a vehicle.

CVT transmissions are different from the prior art

Embodiments known. Due to the continuously variable transmission suitable ratios can be achieved in vehicles in each case in comparison with gears with fixed gears. A special

Application of such CVT transmissions are small vehicles, such as

for example, two-wheelers, tricycles (so-called Tucktucks), snowmobiles, quads or scooters. In such CVT transmissions are common

Centrifugal governor for adjusting a position of a belt on a belt

Used conical disk pair. Depend on the speed depending on the speed

Centrifugal weights of the centrifugal governor thereby their radial position, whereby an axial distance between two conical disks is changed and thereby a ratio of the transmission is changed. A disadvantage of such arrangements, however, is that no controlled intervention in the

Transmission ratio of the CVT transmission is possible. Here it would be

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 in 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 or regulated engagement 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 or pneumatic energy. Thus, the CVT transmission can each be operated at an optimum operating point. Here, the adjusting device comprises a double-acting actuator, which is connected to the axially movable conical disk to adjust these by means of pneumatic force. This allows a simple and compact design can be realized. Furthermore, a fast switching time to change a translation can be made possible by the double-acting actuator. The double-acting actuator is pneumatically acted upon by a first side and a second side, so that the double-acting actuator has two active axial directions of movement. By means of the control unit can thus be made in both axial directions of movement a targeted and active intervention.

The dependent claims show preferred developments of the invention.

Preferably, the CVT transmission further comprises a vacuum source which is connectable to a first pneumatic chamber and a second pneumatic chamber on the double-acting actuator. The vacuum source is preferably a suction pipe of an internal combustion engine. Thus, according to the invention a

Actuation of the double-acting actuator active by means of negative pressure in both

Adjustment directions of the axially movable conical disk are possible.

More preferably, the double-acting actuator is mechanically connected to the axially movable conical disk. Preferably, a rod is provided for this purpose as a mechanical connection, which transmits an axial movement of the double-acting actuator to the axially movable conical disk. More preferably, the axially movable conical disk is mounted on a bearing unit. This allows a particularly compact design of the CVT transmission can be achieved. The bearing unit preferably comprises a bearing sleeve, which is connected to the double-acting actuator for axial adjustment.

More preferably, the actuator is a double-acting piston. The piston is preferably arranged in a cylinder and a piston rod is used for mechanical connection with the axially movable conical disk. As a result, a simple and robust structure for the double-acting actuator can be provided.

Further, the CVT transmission preferably includes centrifugal weights, which are arranged on the axially movable conical disk. Here are the

Centrifugal weights as a function of a rotational speed of the axially movable

Conical disk 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 be realized and it is a lesser additional

Energy requirement necessary. This results in a very simple structure.

Furthermore, the present invention relates to an internal combustion engine comprising a CVT transmission according to the invention. The internal combustion engine comprises

Preferably at least one cylinder and a cylinder leading to the intake manifold, wherein the suction pipe is connected to the pneumatic actuator of the CVT transmission to provide the pneumatic force for adjusting the CVT transmission. Preferably, the suction tube is doing with the

Pneumatic storage connected. By using the suction pipe, a negative pressure for pneumatic adjustment of the CVT transmission can thus be used. This is particularly advantageous because the negative pressure at

Internal combustion engine with intake manifold anyway exists and can be used in addition to setting a gear ratio of a CVT transmission.

Furthermore, the present invention relates to a vehicle comprising a CVT transmission according to the invention and / or an inventive

Internal combustion machine. 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

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

FIG. 1 is a schematic representation of a structure of a CVT

Transmission for a small vehicle according to an embodiment of the invention, and

Figure 2 is a sectional view of the CVT transmission of Figure 1.

Preferred embodiment of the invention

Hereinafter, with reference to Figs. 1 and 2, a CVT transmission 1, i. a continuously variable, continuously variable transmission, according to a preferred embodiment of the invention described in detail.

As can be seen from FIG. 1, the CVT transmission 1 comprises a

Conical disk pair 2 with a fixed conical disk 20 and an axially movable conical disk 21. As a driven element 13 is a second

Conical pulley. The two cone pulley pairs are in a known manner via a belt 12, in particular a belt, connected to each other.

The first conical disk pair 2 is on a crankshaft 1 1 a

Internal combustion engine 10 is arranged. The crankshaft 1 1 is fixedly connected to the stationary conical disk 20. The crankshaft 1 1 is mounted on a housing 14.

The CVT transmission 1 further comprises centrifugal force elements 3, which are arranged on the axially movable conical disk 21. In this embodiment, the centrifugal elements are 3 balls. Alternatively, solid cylinders or hollow cylinders or the like can be used.

Furthermore, the CVT transmission 1 comprises a support element 4, which is arranged on the axially movable conical disk 21. The centrifugal force elements 3 are arranged between the support element 4 and the axially movable conical disk 21. At the axially movable conical disk 21 is at the to

Supporting element 4 directed side provided a corresponding running surface 22, along which move the centrifugal elements.

For adjusting an axial position of the axially movable conical disk 21, an adjusting device 5 is now provided. The adjusting device 5 is provided as a pneumatic adjusting device and comprises a double-acting actuator 51, which is connected to the axially movable conical disk 21. The double-acting actuator 51 is formed in this embodiment as a piston.

The double-acting actuator 51 is connected via a rod 52 with a bearing unit 56 on which the axially movable conical disk 21 is mounted. The bearing unit 56 comprises an inner sleeve 53, an outer sleeve 54 and a bearing 55 arranged between the inner sleeve and the outer sleeve.

As can be seen from Figure 2, the inner sleeve 53 is fixed by the

Cone pulley 20 passed. Furthermore, a cylindrical sleeve portion 41 is provided on the support member 4, on which the inner sleeve 53 is slidably disposed. The inner sleeve 53 is fixedly connected to the axially movable conical disk 21. The bearing 55 interrupts a transmission of rotation of the crankshaft 1 1 on the adjusting device 5. However, the rotation of the crankshaft 1 1 is on the sleeve portion 41 and the inner sleeve 53 to the axially movable

Conical disk 21 transmitted.

The double-acting actuator 51 divides the inner region of a cylinder 58 into two regions, namely a first pneumatic chamber 15 and a second pneumatic chamber 25. Both chambers can have different sizes and / or shapes.

As can be seen from Figures 1 and 2, the adjusting device 5 is connected to a suction pipe 9 of the internal combustion engine 10. The suction tube 9 provides a vacuum source for the actuator 5 ready. The suction pipe 9 is connected via a first line 16 to a vacuum accumulator 7. The vacuum accumulator 7 is then connected via a second line 17 with the adjusting device 5. In the first line 16 is an automatically closing check valve 18 provide. The second line 17 leads directly into the first pneumatic chamber 15, wherein a third line 29 branches off at a branch 19 from the second line 17.

As can be seen from FIG. 2, a first controllable control valve 8 is arranged in the second line 17 between the branch 19 and the adjusting device 5. A second controllable control valve 28 is disposed in the third conduit 29. The first and second controllable control valve 8, 28 is controlled in each case by means of a control unit 6.

As can be seen from Figure 2, the third line 29 opens in the second

Pneumatic room 25.

Thus, according to the invention by means of the control unit 6, a pressure level in the first pneumatic chamber 15 and in the second pneumatic chamber 25 by

corresponding position of the first control valve 8 and the second control valve 28 can be adjusted. Due to the respective pressure differences between the first and second pneumatic space 15, 25 takes place an axial movement of the piston, which is indicated in Figure 2 by the double arrow A. Since the piston over the Rod 52 and the bearing unit 56 is connected to the axially movable conical disk 21, thus takes place an axial adjustment of the conical disk 21st

According to the invention, the actuator 51 can thus be actively controlled in two active, in the axial direction X-X extending directions of movement by means of the control unit 6. Thus, according to the invention, an increase in a translation or a reduction of a translation can be actively controlled by means of negative pressure. In this case, an adjustment can take place with or against the centrifugal elements.

By using the double-acting piston in the cylinder 58, a very robust and durable construction can be achieved.

Thus, according to the present invention in the internal combustion engine 10 in the intake manifold 9 existing negative pressure as pneumatic energy for adjusting a

Translation of the CVT 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, a vacuum supply of the vacuum accumulator 7 can thus be ensured constantly and thus a simple and reliable active adjustment of the axially movable conical disk 21 in both axial directions can be achieved by means of pneumatic force.

The double-acting actuator 51 is preferably arranged at one axial end of the crankshaft 1 1. 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 force elements 3 can 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 double-acting actuator 51 also a retrofitting of existing CVT transmissions can also be made possible.

The vacuum accumulator 7 is particularly preferably arranged in a hollow frame of a vehicle. There is no further space required for this

Low pressure accumulator in the vehicle 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 for the invention to be used on a secondary side, ie on the output element 13 or even on both sides at the same time.

By the possibility according to the invention of an active, exact adjustment of a change of a gear ratio in both directions by means of

Control unit 6 can thus achieve an increase in efficiency of the CVT transmission, which has a positive effect on exhaust emissions and fuel consumption.

In the embodiment, an adjustment of the double-acting actuator has been described by means of negative pressure. It should be noted, however, that in principle an adjustment by means of overpressure is possible. For this purpose, only one overpressure source would have to be provided, which is used to adjust the double-acting actuator 51.

Furthermore, the first control valve 8 and the second control valve 28 are preferably capable of the first pneumatic chamber 15 and / or the second

Pneumatic space 25 also to be applied to ambient pressure 39. As a result, in particular a simple and quick return of the double-acting actuator 51 can be made possible in a starting position.

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

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) which is set up to actuate the setting device (5) in order to change the position of the axially movable conical disk (21),

wherein the adjusting device (5) is a pneumatic adjusting device (5), which adjusts the axially movable conical disk (21) by means of pneumatic force, and

wherein the adjusting device (5) has a double-acting actuator (51) such that the double-acting actuator (51) by means of pneumatic force in a first and a second axial direction (X-X) is adjustable.

CVT transmission according to claim 1, characterized in that the double-acting actuator (51) has a space in a first

Pneumatic space (15) and a second pneumatic space (25) divided.

CVT transmission according to one of the preceding claims, further comprising a vacuum source which is connectable to the first and / or second pneumatic space.

4. CVT transmission according to claim 3, characterized in that the

Vacuum source is a suction pipe (9) of an internal combustion engine.

5. CVT transmission according to one of the preceding claims, further

comprising a rod (52) which is connected to the double-acting actuator (51) and the axially movable conical disk (21). CVT transmission according to one of the preceding claims, characterized in that the axially movable conical disk (21) is mounted on a bearing unit (56).

CVT transmission according to one of the preceding claims, further comprising centrifugal force elements (3) which are arranged on the axially movable conical disk (21).

CVT transmission according to one of the preceding claims, further comprising a pneumatic accumulator (7), in particular a

Vacuum reservoir.

Internal combustion engine comprising a CVT transmission according to one of the preceding claims.

Internal combustion engine according to Claim 9, comprising a suction pipe (9) leading to a cylinder of the internal combustion engine, the suction pipe (9) being connected to the adjusting device (5) of the CVT transmission in order to produce a pneumatic force for the axial adjustment of the axially movable conical disk (21). provide.

1 1. Internal combustion engine according to claim 9 or 10, characterized in that a vacuum reservoir (7) between the suction pipe (9) and the adjusting device (5) is arranged.

12. A vehicle comprising a CVT transmission according to one of claims 1 to 8 and / or an internal combustion engine according to one of claims 9 to 1 1.

Vehicle according to claim 12, further comprising a vehicle frame, in particular a tube, which is designed as a vacuum accumulator.

14. Vehicle according to claim 12 or 13, characterized in that the vehicle is a small vehicle, in particular a two-wheeler or a tricycle or a quad or a snowmobile.