Actuation assembly and method for hydraulically actuating at least two sub-clutches / brakes - Patent Application 20070122999

Abstract

The present invention relates to an actuation assembly (9) for hydraulically actuating at least two sub-clutches / brakes (11, 12), where during actuation of the sub-clutches / brakes (11, 12) the respective air paths are filled, after which each sub-clutch / brake (11, 12) transmits torque. To quickly fill the air paths, the actuation assembly (9) has at least one hydraulic functional air surface and at least one functional pressing surface, which is larger than the functional air surface to generate the necessary pressing force to transmit the torque. To simplify the actuation of the at least two sub-clutches / brakes from the viewpoint of production and / or functionality, the actuation assembly (9) has a common air connection (20) to fill the air paths of the sub-clutches / brakes (11, 12).

Description

[Technical Field]

[0001] The present invention relates to an actuation assembly and method for hydraulically actuating at least two sub-clutches / brakes, wherein during actuation of the sub-clutches / brakes, an air path is filled, and then each sub-clutch / brake transmits torque to quickly fill the air path, the actuation assembly having at least one hydraulic functional air surface and at least one functional pressing surface, the at least one functional pressing surface being larger than the functional air surface to generate the pressing force required to transmit the torque. [Background technology]

[0002] From patent document 1 a dual clutch for distributing a variable torque to two output shafts is known, which dual clutch comprises an outer disc carrier that can be driven to rotate about a rotation axis, a first inner disc carrier, a first disc pack for transmitting torque between the outer disc carrier and the first inner disc carrier, a second inner disc carrier, where the first inner disc carrier and the second inner disc carrier are arranged rotatably relative to each other about the rotation axis, and a second disc pack for transmitting torque between the outer disc carrier and the second inner disc carrier. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Published Application No. 2019 / 219971 Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to simplify the operation of at least two sub-clutches / brakes from a production and / or functionality standpoint. [Means for solving the problem]

[0005] This object is achieved by an actuation assembly for hydraulically actuating at least two sub-clutches / brakes. During actuation of the sub-clutches / brakes, an air path is filled, and then each sub-clutch / brake transmits torque and quickly fills the air path. The actuation assembly has at least one hydraulic functioning air surface and at least one functioning pressing surface, the at least one functioning pressing surface being larger than the functioning air surface to generate the pressing force required to transmit torque. The actuation assembly has a common air connection to fill the air paths of the sub-clutches / brakes. The common air connection is a hydraulic connection, and may be via a hydraulic line or hydraulic flow path, through which a hydraulic medium can be applied to the hydraulic functioning air surfaces. The hydraulic functioning air surfaces are provided, for example, on a piston that can move back and forth within a hydraulic cylinder. Two hydraulic air surfaces provided on the two pistons can also be supplied with a hydraulic medium via the common air connection. The piston(s) may also be referred to as air pistons. The sub-clutches / brakes are preferably wet clutches or brakes, in particular multi-plate clutches or multi-plate brakes. In this wet application, the air path is advantageously large enough to reduce unwanted friction torque during operation. When torque transmission is required, the air path or air path area needs to be traversed as quickly and accurately as possible. For certain applications, especially torque vectoring, two clutches are also required to decouple the drive in addition to performing the torque distribution function. Therefore, the air path area needs to be large and fill quickly. The one or two functional air surfaces are advantageously significantly smaller than the functional pressure surface. The relatively small functional air surface allows the air path to fill quickly. A significantly larger functional pressure surface is suitable for increasing the pressure force. The number of required connections can be reduced from four to three by a common air connection, through which hydraulic medium is supplied to the common functional air surface or to two separate functional air surfaces.

[0006] A preferred exemplary embodiment of the actuation assembly is characterized in that each sub-clutch / brake is assigned to a pressure connection via which the sub-clutches / brakes can be subjected to different pressure forces. The actuation assembly advantageously includes exactly two sub-clutches / brakes to enable a desired torque distribution on both sides of the drive during torque vectoring in the drive train. The hydraulic medium can be supplied to the functional pressure surfaces independently of each other via separate pressure connections to ensure the desired torque distribution in the drive train.

[0007] A further preferred embodiment of the actuating assembly is characterized in that it comprises at least two annular pistons, each of which has an annular surface hydraulically connected only to a common air connection. The two annular surfaces of the annular pistons can be supplied with hydraulic medium via the common air connection to quickly fill the air paths of both sub-clutches / brakes. However, the two annular pistons can also be subjected to the desired contact pressure independently of each other via separate pressure connections.

[0008] A further preferred embodiment of the actuation assembly is characterized in that the annular pistons each have a stepped side surface, with the stepped side surface forming a respective annular surface. The annular pistons define a common annular air space in the axial direction by the annular surfaces of the stepped side surfaces of the annular pistons. The common air connection is connected to the common annular air space, for example, via a radial passage in the housing body. The annular pistons with stepped sides can be manufactured and assembled cost-effectively with the desired functionality.

[0009] A further preferred embodiment of the actuation assembly is characterized in that the annular pistons with annular surfaces are arranged in a radially telescopic manner, in this way the axial installation space can be efficiently saved.

[0010] A further preferred embodiment of the actuation assembly is characterized in that the annular pistons can be moved axially relative to one another with a sealing device interposed therebetween, in this way radial installation space can also be advantageously saved.

[0011] A further preferred embodiment of the actuation assembly is characterized in that the pressure connection and the common air connection are provided on a housing body in which the annular piston is also accommodated so as to be movable back and forth. By sharing the common air connection with the two pistons, seals and hydraulic inlets can be advantageously omitted. The pressure exerted hydraulically through the various connections can be varied independently of one another using suitable diameters at the sealing points.

[0012] A further preferred exemplary embodiment of the actuation assembly is characterized in that two annular pressure spaces and a common annular air space are formed in the housing body, the annular spaces being hydraulically separated from one another by sealing devices and / or annular pistons.

[0013] A further preferred exemplary embodiment of the actuation assembly is characterized in that the annular piston is connected to the disc pack via a bearing device and a pressure component for force transmission. Meanwhile, the two annular pistons can receive hydraulic pressure together via a common air connection. Additionally, the two annular pistons can receive hydraulic pressure independently from each other via separate pressure connections. The hydraulically generated pressure is transmitted to the disc pack of the disc clutch or disc brake via the bearing device and the pressure component.

[0014] A further preferred embodiment of the actuation assembly is characterized in that a hydraulic function air surface is provided on at least one piston, which can move back and forth within the hydraulic cylinder. For example, the hydraulic function air surface may be provided on only one piston, which is connected to several pressure pistons. A function air surface may also be provided on multiple pistons, each connected to a pressure piston. The air path can be quickly filled via a common air connection and a suitable mechanical connection with one or more pressure pistons. The function pressure surfaces independently provided on the pressure pistons can be supplied with hydraulic medium independently from each other via separate pressure connections, for example, to realize torque distribution or torque vectoring in a drive train.

[0015] In the method for hydraulically actuating at least two sub-clutches / brakes by means of the aforementioned actuation assembly, the above object is alternatively or additionally achieved in that the air paths of the sub-clutches / brakes are filled via a common air connection, and then the pressing forces necessary to generate the desired torque transmission via the functional pressing surfaces of the sub-clutches / brakes are generated independently of each other.

[0016] Further advantages, features and details of the invention will become apparent from the following description in which various exemplary embodiments are set forth in detail with reference to the drawings. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a half cross-sectional view of a dual clutch having two radially nested sub-clutches that can be actuated through an actuation assembly with a common air connection. [Figure 2] FIG. 2 is an enlarged cross-sectional view of FIG. [Figure 3] FIG. 3 is an enlarged cross-sectional view of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0018] 1 to 3 show a dual clutch 10 in half section and enlarged section, which has two clutches 11, 12 configured as multi-plate clutches. The two clutches 11, 12 are also referred to as a first clutch 11 and a second clutch 12.

[0019] In the specification and claims, the two clutches 11 and 12 are more generally referred to as sub-clutches / brakes 11, 12. The background to this is that the actuating assembly 9 can be used both to actuate a clutch, in particular a multi-plate clutch, and to actuate a brake, in particular a multi-plate brake.

[0020] The dual clutch 10 is arranged in a housing 3 which comprises two housing bodies 5, 6 which are fixed to one another using screws 4. Two shafts 1, 2 are rotatably mounted in the housing 3 with the aid of bearing arrangements 7, 8. The shafts 1, 2 are also referred to as the first shaft 1 and the second shaft 2.

[0021] The first clutch 11 comprises a first disc pack 15, while the second clutch 12 comprises a second disc pack 16. The two disc packs 15, 16 comprise friction discs and steel discs in frictional contact for torque transmission, assisted by pressure elements 17, 18. The discs of the disc packs 15, 16 are arranged alternately and are suspended radially inward and radially outward in a known manner on disc carriers.

[0022] The first disc carrier 13 is non-rotatably fixed to the first shaft 1. The second disc carrier 14 is non-rotatably fixed to the second shaft 2. A first spring 37 is assigned to the first disc pack 15. A second spring 38 having a spring retainer ring 40 is assigned to the second disc pack 16.

[0023] The first pressure part 17 can be actuated by a first piston 21 with an intervening bearing arrangement 43 configured as an axial bearing. The second pressure part 18 can be actuated by a second piston 22 with an intervening bearing arrangement 44 configured as an axial bearing.

[0024] When actuated by the first piston 21 or the second piston 22, the air clearance between the discs of the disc pack 15, 16 must first be overcome in a known manner, after which the discs are pressed together with a large force to transmit torque. The air clearance that must be overcome is also referred to as the air path.

[0025] According to an essential aspect of the invention, the actuation assembly 9 comprises a common air connection 20, via which a common hydraulic function air surface 19 can be hydraulically actuated specifically to overcome the air clearances of the two clutches 11, 12. As soon as the air clearances or air paths of the clutches 11, 12 have been overcome, the two clutches 11, 12 can be subjected to different contact pressures via separate pressure connections 31, 32.

[0026] The first piston 21 has a first annular surface 23 on a stepped side 25. The second piston 22 has a second annular surface 24 on a stepped side 26. The two annular surfaces 23, 24 together represent a common hydraulically functional air surface 19, which can be hydraulically actuated via a common air connection 20.

[0027] Pressurization of the common hydraulic function air surface 19 occurs via a common annular air space 28. The common annular air space 28 is connected to the common air connection 20 on the housing body 6 via a radial connecting passage 29.

[0028] The two pistons 21, 22 can move axially relative to each other with the sealing device 30 interposed therebetween. The two pistons 21, 22 are arranged radially nested one inside the other. The first press connection 31 is connected to a first annular press space 33, which is arranged radially inside the second annular press space 34, and the second annular press space 34 is connected to the second press connection 32.

[0029] The functional pressure surfaces 41, 42 provided on the two pistons 21, 22, which can be subjected to a contact pressure via the pressure connections 31, 32, are significantly larger than the hydraulic functional air surface 19. This offers the advantage, inter alia, that the air clearance can be overcome quickly and then the two clutches 11, 12 can be subjected to different contact pressures independently of one another via the separate pressure connections 31, 32.

[0030] The pressure connections 31, 32 and the common air connection 20 are provided on the housing body 6, which also includes annular spaces 33, 34 and 28. A plurality of static sealing devices 35, 36 and 39 are provided for sealing purposes. The sealing devices include both static and dynamic seals. When all connections, i.e., the two pressure connections and the common air connection, are depressurized, the separation functionality can be advantageously performed. [Explanation of symbols]

[0031] 1 First Shaft 2 Second Shaft 3. Housing 4 screws 5 Housing body 6 Housing body 7 Bearing device 8 Bearing device 9 Actuation Assembly 10 Dual Clutch 11 First Clutch 12 Second clutch 13 First Disk Carrier 14 Secondary Disk Carrier 15 First Disc Pack 16 Second Disc Pack 17 First pressure part 18 Second pressure part 19 Hydraulic Function Air Surface 20 Common Air Connection 21 First Piston 22 Second Piston 23 First Annular Surface 24 Second Annular Surface 25 Stepped Side 26 Stepped Side 28 Common annular air space 29 Connecting Channels 30 Sealing device 31 first pressure connection part 32 second press connection part 33 First annular pressing space 34 Second annular pressing space 35 Sealing device 36 Sealing device 37 First Spring 38 Second Spring 39 Sealing device 40 Spring retainer ring 41 Functional pressing surface 42 Functional pressing surface 43 Bearing device 44 Bearing device

Claims

1. An actuation assembly (9) for hydraulically actuating at least two sub-clutches or brakes (11, 12), each of which is comprised of a disc pack (15, 16), comprising: the actuating assembly (9) comprises at least two annular pistons (21, 22), each having an annular surface (23, 24) and a functional pressing surface (41, 42), the annular surfaces (23, 24) of both annular pistons (21, 22) forming a hydraulic functional surface (19); In an actuation assembly (9), during the actuation of the sub-clutches or brakes (11, 12), an air path, which is an air clearance between the disks of each disk pack (15, 16), is filled, and then each sub-clutch or brake (11, 12) transmits torque, the functional pressing surfaces (41, 42) and the hydraulic functional surface (19) are configured to quickly fill the air path, and the functional pressing surfaces (41, 42) have a larger area that receives a pressing force than the hydraulic functional surface (19) to generate the pressing force required to transmit the torque, The press-fit connection portions (31, 32) and the common connection portion (20) are provided on a housing body (6), and the annular pistons (21, 22) are accommodated in the housing body (6) so as to be movable back and forth; the common connection (20) is hydraulically connected to each of the at least two annular pistons (21, 22) and configured to pressurize a hydraulically functional surface (19); An actuation assembly (9), characterized in that each of the disk packs (15, 16) is assigned a pressure connection (31, 32), via which each of the disk packs (15, 16) can be subjected to different pressure forces for frictional contact from the functional pressure surfaces (41, 42).

2. 2. An actuation assembly according to claim 1, characterized in that the annular pistons (21, 22) each have a stepped side surface (25, 26) on which the respective annular surfaces (23, 24) are formed.

3. 3. An actuating assembly according to claim 1 or 2, characterized in that the annular pistons (21, 22) with their annular surfaces (23, 24) are arranged in a radially telescopic manner.

4. 2. An actuation assembly according to claim 1, characterized in that the annular pistons (21, 22) are axially movable relative to one another with a sealing device (30) interposed therebetween.

5. An operating assembly as described in claim 1, characterized in that annular pressing spaces (33, 34) hydraulically connected to the pressing connection parts (31, 32) and an annular air space (28) hydraulically connected to the common connection part (20) are formed within the housing body (6), and the annular pressing spaces (33, 34) and the annular air space (28) are hydraulically separated from each other by sealing devices (35, 36, 39) and / or the annular pistons (21, 22).

6. 2. An actuation assembly according to claim 1, characterized in that the annular pistons (21, 22) are connected to the disc packs (15, 16) for force transmission via bearing arrangements (43, 44) and pressure components (17, 18).

7. 2. A method for hydraulically actuating at least two sub-clutches or brakes (11, 12) by means of an actuation assembly (9) according to claim 1, characterized in that the air paths of the sub-clutches or brakes (11, 12) are filled via the common connection (20) and then the pressing forces necessary to generate a desired torque transmission via the functional pressing surfaces (41, 42) of the sub-clutches or brakes (11, 12) are generated independently of each other.

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