CN111566391A

CN111566391A - Switching assembly for adjusting a first disk set and a second disk set of a conical disk transmission

Info

Publication number: CN111566391A
Application number: CN201980007303.7A
Authority: CN
Inventors: R·施特尔; M·切塞克; S·克普夫勒
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2018-02-28
Filing date: 2019-02-01
Publication date: 2020-08-21
Anticipated expiration: 2039-02-01
Also published as: DE112019001035A5; JP6938780B2; CN111566391B; JP2020535365A; DE102018104558A1; WO2019166046A1

Abstract

The invention relates to a switching assembly (1) for adjusting a first disk set (2) and a second disk set (3) of a conical disk transmission (4); at least one first actuator (5) for actuating the first disk stack (2) and a second actuator (6) for actuating the second disk stack (3), and a valve (7) which connects the second actuator (6) to a reservoir (8) for a fluid for operating the switching assembly (1) in a switchable manner; wherein the valve (7) is a passively switched valve having at least one first switching state (9) and a second switching state (10).

Description

Switching assembly for adjusting a first disk set and a second disk set of a conical disk transmission

Technical Field

The invention relates to a switching assembly for adjusting a first and a second disk stack of a conical disk transmission.

Background

Switching assemblies for operating a conical pulley transmission (CVT transmission) are known. These switching assemblies are typically operated with hydraulic fluid. In order to adjust and compress the disk stack, the actuator (e.g., pump) used in the switching assembly must be dimensioned such that it is able to cover the power peaks of the relevant driving situation.

A conical-disk wound gear usually comprises a first disk stack and a second disk stack, wherein each disk stack has a fixed conical disk and a conical disk which can be displaced in the axial direction. By displacement of the conical disks of the disk stacks, the winding means can be displaced from a small effective radius on one disk stack to a large effective radius on the same disk stack (and in the opposite manner on the respective other disk stack).

The disk stack connected to the drive unit of the vehicle is referred to as the main disk stack. If the master disk stack is now adjusted in which the winding device is shifted from an Overdrive (OD state; large effective radius) state to a Underdrive (UD state; small effective radius) state, the fluid must be discharged from the master disk stack as quickly as possible. It is known to use electromagnetically actuated valves for this purpose, which support an actuator that discharges the fluid.

There is always a need to reduce the complexity of the switching assembly and simplify the components used.

Disclosure of Invention

The invention is based on the object of providing a switching assembly which is as simple as possible in construction.

This task is solved with a switching component according to the features of independent claim 1. Further advantageous embodiments of the invention are given in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technically expedient manner and can define further embodiments of the invention. In addition, the features specified in the claims are set forth and explained in detail in the description, wherein further preferred embodiments of the invention are shown.

A switching assembly for adjusting a first disk stack (e.g., a secondary disk stack) and a second disk stack (e.g., a primary disk stack) of a conical disk wrap-around transmission is provided. The switching assembly has at least a first actuator for actuating the first disk stack (for example a pump with alternating conveying direction) and a second actuator for actuating the second disk stack (for example a pump with alternating conveying direction), and a valve which connects the second actuator to a reservoir for a fluid for operating the switching assembly in a switchable manner. The valve is a passively switched valve having at least one switched state and a second switched state.

The use of passively switching valves (i.e. not electronically controlled) can simplify the proposed switching assembly. It is no longer (any longer) necessary to synchronize the actuator and the valve by means of the control unit. In this case, passively switched valves are significantly more cost-effective. Furthermore, no electrical connection of the valve (for operation and for regulation) is required.

In particular, the valve can be switched by a pressure difference of the fluid existing between the first line section and the second line section.

In particular, between the first and second switching states, further switching states exist which form a transition (continuously adjustable as a function of the pressure difference) between the completely open connection and the completely closed connection.

Preferably, the pressure difference can be generated (during operation of the switching assembly) by means of a pressure reducer (cross-sectional constriction, flow resistance).

Preferably, the pressure reducer is a throttle plate (blend).

The throttle screen comprises in particular a reduction of the flow cross section of the line through which the fluid flows. Here, the pressure upstream of the throttle screen is generally higher than the pressure downstream of the throttle screen. In the present case, this pressure difference caused by the throttle screen is used to actuate the valve.

In particular, the valve is preloaded by a spring.

Preferably, the valve can be displaced by a spring into a first switching position, wherein in the first switching position the second actuator is fluidically separated from the reservoir by the valve. In the second switching position, the second actuator is fluidically connected to the reservoir via the valve.

The valve is in particular a two-position two-way valve, i.e. having two connections and at least two switching states (if necessary further switching states between the first and second switching states).

The valve is displaceable from a first switching position to a second switching position by the pressure difference and against the action of a spring. If the pressure difference is lower than a predetermined differential pressure, the valve is displaced back into the first switching position by the spring.

In particular, the first actuator is arranged between the store and the first disk stack, and the second actuator is arranged between the first disk stack and the second disk stack. The valve can be switched by a pressure difference of the fluid existing between the first line section and the second line section and generated by the pressure reducer. The pressure reducer

A first fluidic connection arranged between the second actuator and the second disk stack; or

A second fluid-technical connection arranged between the first actuator and the second actuator.

According to a preferred embodiment, a check valve is arranged in the third fluidic connection parallel to the pressure reducer, which check valve blocks the throughflow of fluid from the second disk stack to the first disk stack.

In particular, the switching assembly has a pump, by means of which the valve and the first actuator are fluidically connected to the reservoir.

Further, a method for fast adjustment of a main group of a conical-pulley transmission is proposed. A conical pulley transmission can be operated by means of the switching assembly described above according to one of the preceding claims. The second disk group is a master disk group. The adjustment of the main disk stack from the overdrive state to the underdrive state is effected by discharging fluid from the main disk stack, wherein at least a portion of the discharged fluid is directed to the reservoir by the passively switched valve.

The second actuator can thus be unloaded, which, when this adjustment is made, conveys the fluid from the second disk stack to the first disk stack. Thus, the required rapid decompression in the second disc stack can be supported.

The embodiments for switching the components are particularly equally applicable to the method and vice versa.

Precautions should be taken to: the terms "first", "second", … … are used here primarily (exclusively) to distinguish a plurality of objects, variables or processes of the same type, i.e. the relevance and/or the order of these objects, variables or processes is not necessarily predefined. If dependency and/or order is necessary, this will be explicitly described herein or will be apparent to one of ordinary skill in the art upon examination of the specifically described configuration schemes.

Drawings

The invention and the technical field are explained in detail below with reference to the drawings. It should be noted that the present invention is not limited by the illustrated embodiments. In particular, unless explicitly stated otherwise, some aspects of the implementations set forth in the figures can also be extracted and combined with other components and understanding in this description and/or the figures. It should be noted in particular that the figures and the size ratios shown in particular are purely schematic. The same reference numerals denote the same objects, and therefore, explanations from other drawings can be additionally considered as necessary. The figures show:

FIG. 1: a switching assembly having an electrically regulated valve;

FIG. 2: a first embodiment variant of a switching assembly with passively switching valve;

FIG. 3: a second embodiment variant of the switching assembly with passively switching valve; and

FIG. 4: a vehicle having a cone-pulley transmission.

Detailed Description

Fig. 1 shows a switching assembly 1 with a regulated valve 7. The switching arrangement 1 has a first actuator 5 (pump with alternating conveying direction) for actuating the first disk stack 2 and a second actuator 6 (pump with alternating conveying direction) for actuating the second disk stack 3, as well as a valve 7 which connects the second actuator 6 to a reservoir 8 for a fluid for operating the switching arrangement 1 in a switchable manner.

The conical pulley transmission 4 comprises a first disk stack 2 and a second disk stack 3, wherein each

disk stack

2, 3 has a fixed conical pulley and a conical pulley that can be displaced in the axial direction. By displacing the conical disks of the disk stacks 2, 3, the winding means 24 can be displaced from a small effective radius on one disk stack to a large effective radius on the same disk stack (and in the opposite manner on the respective other disk stack).

The (second) disc pack 3 connected to the drive unit 22 of the vehicle 21 is referred to as the main disc pack. If the master disk set is now adjusted in which the winding means 24 are shifted from the underdrive state (UD state; small effective radius) to the overdrive state (OD state; large effective radius), the fluid must be discharged from the master disk set as quickly as possible. It is known to use for this purpose an electromagnetically actuated valve 7 which supports a second actuator 6 which discharges the fluid.

Fig. 2 shows a first embodiment variant of the switching arrangement 1 with a passively switching valve 7. Reference is made to the embodiment of figure 1.

The switching arrangement 1 serves for adjusting a first disk stack 2 (secondary disk stack) and a second disk stack 3 (main disk stack) of a conical disk-wound gear 4. The switching arrangement 1 has a first actuator 5 (pump with alternating conveying direction) for actuating the first disk stack 2 and a second actuator 6 (pump with alternating conveying direction) for actuating the second disk stack 3, as well as a valve 7 which connects the second actuator 6 to a reservoir 8 for a fluid for operating the switching arrangement 1 in a switchable manner. The valve 7 is a passively switched valve having at least one first switching state 9 and a second switching state 10 and, if appropriate, further switching states.

The valve 7 can be switched by a pressure difference 13 of the fluid existing between the first line section 11 and the second line section 12. A first line section 11 connects the second actuator 6 with the second disk stack 3. The second line section 12 connects the second actuator 6 with the first actuator 5. By means of the pressure reducer 14, here by means of the throttle plate, the pressure difference 13 can be generated (when the switching assembly 1 is operating).

The valve 7 is preloaded by a spring 15. The valve 7 can be displaced by a spring 15 into a first switching position 9, wherein in the first switching position 9 the second actuator 6 is fluidically separated from the reservoir 8 by the valve 7 (shown here). In the second switching position 10, the second actuator 6 is fluidically connected to the reservoir 8 via the valve 7.

The valve 7 is a two-position two-way valve, i.e. has two connections and two switching states 9, 10 (and possibly other switching states). The valve 7 can be displaced from the first switching position 9 into the second switching position 10 by a pressure difference 13 and against the action of a spring 15. If the pressure difference 13 is lower than the predetermined differential pressure, the valve 7 is displaced back into the first switching position 9 by the spring 15.

The first actuator 5 is arranged fluidically between the reservoir 8 and the first disk stack 2, and the second actuator 6 is arranged between the first disk stack 2 and the second disk stack 3. The pressure reducer 14 is arranged in a first fluidic connection 16 between the second actuator 6 and the second disk stack 3. A check valve 19 is arranged in a third fluid connection 18 parallel to the pressure reducer 14, which check valve blocks the throughflow of fluid from the second disk stack 3 to the first disk stack 2.

Furthermore, the switching assembly 1 has a pump 20, by means of which the valve 7 and the first actuator 5 are fluidically connected to the reservoir 8.

The adjustment of the main disk stack (here the second disk stack 3) from the overdrive state to the underdrive state is effected by discharging fluid from the main disk stack, wherein at least a portion of the discharged fluid is directed to the reservoir 8 via the passively switched valve 7. The second actuator 6, which during this adjustment conveys fluid from the second disk stack 3 to the first disk stack 2, can thus be unloaded. Thus, the required rapid decompression in the second disc stack 3 can be supported.

Fig. 3 shows a second embodiment variant of the switching arrangement 1 with a passively switching valve 7. Reference is made to the embodiment of figure 2.

In contrast to the first variant embodiment, the pressure reducer 14 (throttle plate) is arranged in the second fluidic connection 17 between the first actuator 5 and the second actuator 6.

Fig. 4 shows a vehicle 21 with a conical pulley transmission 4. The vehicle 21 comprises a drive unit 22 which can be connected in a switchable manner to the conical-pulley transmission 4 by means of a clutch 23. The conical disk winding gear 4 comprises a main disk stack (second disk stack 3) and a secondary disk stack (first disk stack 2), which are connected to one another by a winding device 24. The main disk group introduces the torque of the drive unit 22 into the conical-disk transmission 4. Starting from the conical-pulley transmission 4, the torque is transmitted via the secondary pulley set to the wheels 25 of the vehicle 21.

List of reference numerals

1 switching assembly

2 first disk group

3 second disk group

4-cone-disc winding type transmission device

5 first actuator

6 second actuator

7 valve

8 storage device

9 first switching state

10 second switching state

11 first line section

12 second line section

13 pressure difference

14 pressure reducers

15 spring

16 first connection part

17 second connecting part

18 third connecting part

19 check valve

20 pump

21 vehicle

22 drive unit

23 Clutch

24-winding device

25 wheel

Claims

1. A switching assembly (1) for adjusting a first disc set (2) and a second disc set (3) of a conical disc wrap-around transmission (4); at least one first actuator (5) for actuating the first disk stack (2) and a second actuator (6) for actuating the second disk stack (3), and a valve (7) which connects the second actuator (6) to a reservoir (8) for a fluid for operating the switching assembly (1) in a switchable manner; wherein the valve (7) is a passively switched valve having at least one first switching state (9) and a second switching state (10).

2. Switching assembly (1) according to claim 1, wherein the valve (7) can be switched by a pressure difference (13) of the fluid existing between the first line section (11) and the second line section (12).

3. Switching assembly (1) according to claim 2, wherein the pressure difference (13) is generated by a pressure reducer (14).

4. Switching assembly (1) according to claim 3, wherein the pressure reducer (14) is a throttle plate.

5. Switching assembly (1) according to one of the preceding claims, wherein the valve (7) is pre-tensioned by means of a spring (15).

6. The switching assembly (1) according to claim 5, wherein the valve (7) is displaceable by the spring (15) into the first switching position (9), wherein in the first switching position (9) the second actuator (6) is fluidically separated from the reservoir (8) by the valve (7).

7. The switching assembly (1) according to any one of the preceding claims, wherein the first actuator (5) is arranged between a reservoir (8) and a first disc stack (2), and the second actuator (6) is arranged between the first disc stack (2) and the second disc stack (3); wherein the valve (7) can be switched by a pressure difference (13) of the fluid which is present between the first line section (11) and the second line section (12) and which is generated by a pressure reducer (14); wherein, the pressure reducer (14)

-arranged in a first fluidic connection (16) between the second actuator (6) and the second disc pack (3); or

-arranged in a second fluidic connection (17) between the first actuator (5) and the second actuator (6).

8. A switching assembly (1) according to claim 7, wherein a non-return valve (19) is arranged in a third fluid technology connection (18) parallel to the pressure reducer (14), which non-return valve blocks a throughflow of the fluid from the second disc set (3) to the first disc set (2).

9. The switching assembly (1) according to one of the preceding claims, wherein the switching assembly (1) has a pump (20) by means of which the valve (7) and the first actuator (5) are fluidically connected with the reservoir (9).

10. A method for rapid adjustment of a main disc set of a conical-disc wound transmission (4), wherein the conical-disc wound transmission (4) can be handled by a switching assembly (1) according to one of the preceding claims, wherein the second disc set (3) is the main disc set; wherein the adjustment of the main disc stack from the overdrive state to the underdrive state is achieved by discharging fluid from the main disc stack, wherein at least a part of the discharged fluid is directed to a reservoir (9) by means of a passively switched valve (7).