WO2017016732A1

WO2017016732A1 - Pneumatically adjustable continuously variable transmission

Info

Publication number: WO2017016732A1
Application number: PCT/EP2016/063033
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: TW201710615A; DE102015214153A1; CN107850194A; EP3329147A1

Abstract

The invention relates to a continuously variable transmission (CVT) comprising: a V-pulley (2) that includes 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) designed to actuate the adjusting device (5) in order to change the position of the axially movable conical disk (21). The adjusting device (5) is a pneumatic adjusting device that moves the axially movable conical disk (21) by a pneumatic force.

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 actively 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. Thus, the CVT transmission can each be operated at an optimum operating point. The adjusting device comprises a pneumatic space, which is arranged on a rear side of the axially movable conical disk. The back of the axially movable conical disk is the side which is not in contact with the belt of the CVT transmission. By changing a pressure in the pneumatic space is thus a

Axial movement of the conical disk causes. Thus, the axially movable conical disk itself acts as a kind of piston for an adjustment of the translation. As a result, in particular a number of components can be kept low.

The dependent claims show preferred developments of the invention.

Preferably, the pneumatic space is defined by the back of the axially movable conical disk and a cylinder element with bottom. This allows a simple and inexpensive construction can be realized.

The cylinder element is preferably so with the axially movable

Connected cone pulley that rotates the cylinder member together with the axially movable cone pulley. Thus also rotates the defined by the axially movable conical disk and the cylinder element pneumatic space.

Preferably, the axially movable conical disk is axially movable on a sleeve. The sleeve is provided with a rotating shaft, in particular one

Crankshaft of an internal combustion engine, firmly connected.

Preferably, the pneumatic actuator comprises a

Pneumatic memory. The pneumatic accumulator can with overpressure or with To work under pressure. That is, in the pneumatic accumulator there is an overpressure, which is used to adjust the CVT transmission, or alternatively, a negative pressure, which is used to adjust the CVT transmission. Preferably, the pneumatic adjusting device is adapted to adjust the axially movable conical disk by means of negative pressure. When using a pneumatic accumulator, a negative pressure is thus preferably maintained in the pneumatic accumulator. More preferably, the pneumatic accumulator is connected via a connecting line with a vacuum source. A check valve is preferably arranged in the connecting line to allow a shut-off of the connecting line. The check valve is preferably automatically closing and can be adjusted to the respective desired conditions.

According to a preferred embodiment of the invention, a pneumatic line for supplying the pneumatic space with positive pressure and / or negative pressure through the cone pulley pair is disposed therethrough. As a result, a very compact structure can be realized. Particularly preferably, the pneumatic line runs through the crankshaft.

Preferably, the CVT transmission to centrifugal weights, which shift depending on a speed of the conical disks, so that by means of the pneumatic actuator according to the invention only one

Fine adjustment of the gear ratio is necessary.

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

Intake manifold, wherein the intake manifold with the pneumatic actuator of the CVT

Gear is connected to provide the pneumatic force for adjusting the CVT transmission. Preferably, the suction tube is doing with the

Pneumatic room 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 suction pipe anyway exists and in addition to Setting a gear ratio of a CVT transmission can be used.

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

Internal combustion engine.

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

Vacuum can be used as a pneumatic accumulator for providing 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. Gas-tight manner must be closed 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 Embodiments of the invention will now be described in detail with reference to the accompanying drawings. In the drawing is:

Figure 1 is a schematic representation of a CVT transmission for a

Small vehicle according to a first embodiment of the invention,

Figure 2 is a schematic sectional view of the CVT transmission of

FIG. 1,

Figure 3 is a schematic representation of a control valve of the first

Embodiment, and Figure 4 is a schematic representation of a control valve according to a second embodiment of the invention.

Preferred embodiments of the invention

Hereinafter, with reference to Figs. 1 to 3, 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 first one

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

Cone pulley pair provided. The two conical disk pairs are connected in a known manner via a belt 12, in particular a belt.

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

Internal combustion engine 10 is arranged. The crankshaft 1 1 is connected to the stationary conical disk 20.

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. The centrifugal force elements 3 are arranged on a rear side 22 of the axially movable conical disk 21.

For adjusting an axial position of the axially movable conical disk 21, a pneumatic adjusting device 5 is now provided. The adjusting device 5 comprises a pneumatic space 50, which is arranged on the rear side 22 of the axially movable conical disk. The pneumatic space 50 is further bounded by a cylinder element 51 with bottom 52 (see FIG. A gasket 53, e.g. an O-ring or the like, is provided between the axially movable cone pulley 21 and the cylinder member 51.

By this arrangement, the cylinder member 51 rotates together with the axially movable cone pulley 21st The axially movable conical disk 21 is fixed on an outer sleeve 54, which is slidably mounted on an inner sleeve 55 in the axial direction XX slidably. As further seen in Figure 1, is a suction pipe 9 of an internal combustion engine

10 connected to a vacuum reservoir 7 via a first line 16. In the first line 16 while a check valve 18 is arranged. A second line 17 is provided as a supply line of the pressure prevailing in the vacuum accumulator 7 pressure to the pneumatic chamber 50. In the second line 17, a control valve 8 is arranged. The control valve 8 is shown in detail in FIG. The control valve 8 is controlled by a control unit 6 in response to a desired

Gear ratio of the CVT transmission provided.

In this embodiment, the control valve 8 is a 3/3-way valve, wherein the control valve 8 can connect on the one hand to the vacuum reservoir 7 and on the other hand with an environment 19 (ambient pressure). A third position is the closed position of the control valve 8, which is shown in FIG. When the control valve 8 connects the vacuum accumulator 7 with the pneumatic chamber 50, a pressure in the pneumatic chamber 50 is reduced, so that the axially movable conical disk 21 is moved axially in the direction of the arrow A (Figure 2). In this case, the axially movable conical disk 21 moves within the

Cylinder member 51, which is arranged rotatably, but not arranged in the axial direction X-X movable. Thus, the distance between the axially movable conical disk 21 and the fixed conical disk 20 becomes larger, so that the belt moves further in the direction of the crankshaft 1 1.

A reduction of the distance between the axially movable conical disk 21 and the stationary conical disk 20 can then again by brief

Opening the control valve 8 for establishing a connection with the environment 19 can be realized.

In this exemplary embodiment, the second line 17 is arranged such that the second line 17 opens from the rear side of the axially movable conical disk 21 into the pneumatic space 15. However, it would also be conceivable that For example, a line through the crankshaft 1 1 is passed

Internally connected to the pneumatic chamber 50.

The crankshaft 1 1 is mounted by means of a bearing 57 on a housing 14.

Thus, according to the invention, it can be utilized that a vacuum present in a suction pipe 9 of an internal combustion engine 10 is used as pneumatic energy for adjusting a ratio of the CVT transmission. 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. As a result, a simple and secure adjustment of the axially movable conical disk 21 is achieved by means of pneumatic force. A

Reset can be done by means of ambient pressure.

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 significant weight reduction of the CVT transmission 1 can be achieved in comparison with the prior art.

The vacuum accumulator 7 is particularly preferably arranged in a cavity of a vehicle. This is then no further space for the

Low pressure accumulator in the vehicle necessary.

Further, in the described first embodiment, the actuator 5 is disposed on a primary side of the CVT, that is, on an input side. Alternatively, it is also possible for the adjusting device to be arranged on a secondary side of the CVT transmission, that is, on the output element 13. Further alternatively, an actuating device is arranged on the primary side and the secondary side.

Due to the possibility according to the invention of an exact setting of a transmission ratio, an increase in the efficiency of the CVT transmission 1 can thus be achieved, which has a positive effect on exhaust emissions and driving dynamics and fuel consumption. Figure 4 shows an alternative embodiment of the control valve 8, which comprises two 2/2-way valves 80, 81 in this embodiment. One of the two 2/2-way valves is between the vacuum reservoir 7 and the

Pneumatic space 50 arranged and the other of the two 2/2-way valves is disposed between the pneumatic chamber 50 and the environment 19.

The present invention 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) arranged to actuate the adjusting device (5) in order to change the position of the axially movable conical disk (21),

wherein the adjusting device (5) comprises a pneumatic space (50), which is arranged on a rear side (22) of the axially movable conical disk (21), so that an axial movement of the axially movable conical disk (21) can be achieved by a change of a pressure in the pneumatic space (50) ) takes place in the axial direction (XX).

CVT transmission according to claim 1, characterized in that the pneumatic space (50) through the rear side (22) of the axially movable conical disk (21) and a cylinder element (51) with bottom (52) is defined.

CVT transmission according to claim 2, characterized in that the cylinder element (51) rotates together with 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 arranged on an outer sleeve (54).

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

comprising a vacuum source, in particular a suction pipe (9) which is connectable to the pneumatic space (50).

6. CVT transmission according to one of the preceding claims, further comprising a control valve (8), wherein the control unit (6) is arranged to set a pressure level in the pneumatic chamber (50) by position of the control valve (8).

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

comprising a pneumatic line (17) for supplying the

Pneumatic space (15), wherein the pneumatic line (17) is passed through the axially movable conical disk (21).

8. 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). 9. internal combustion engine, comprising a CVT transmission according to one of

previous claims.

10. Internal combustion engine according to claim 9, comprising at least one leading to a cylinder suction pipe (9), wherein the suction pipe (9) with the pneumatic adjusting device (5) of the CVT transmission is connected to the pneumatic force for axial displacement of the axially movable

To provide cone pulley (21).

1 1. Internal combustion engine according to claim 6 or 7, characterized in that the suction pipe (9) is connected to a vacuum reservoir (7).

12. A vehicle comprising a CVT transmission according to one of claims 1 to 8, and / or an internal combustion engine according to any one of claims 9 to 1 1. 13. Vehicle according to claim 12, further comprising a vehicle frame, in particular a tube which is designed as a vacuum accumulator (7).

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.