WO2008138506A1 - Double clutch arrangement having axially short nesting of working and compensating space - Google Patents

Abstract

The invention relates to a clutch system for motor vehicle drives having a clutch input shaft and at least two transmission input shafts, each transmission input shaft being connected to the clutch input shaft by an actuatable liquid-lubricated and cooled friction clutch, each friction clutch being actuated by at least one piston of a hydraulic actuator, at least one piston separating a working space and a compensating space, and the piston being guided with the radially outer guide contour thereof on a cylindrical segment of a wall delimiting the compensating space and fastened to the main hub. The piston is guided with the radially inner guide contour thereof in the region of the main hub. The radially inner wall delimiting the balancing space has overflow recesses. The present invention produces a clutch system, which minimizes the clutch-releasing effect of the working space filling subject to centrifugal force.

Description

 Double clutch arrangement with axially short design of working and compensation chamber

description

The invention relates to a clutch system for motor vehicle drives with a clutch input shaft and at least one transmission input shaft, which are all arranged concentrically to a clutch center line, wherein the transmission input shaft is connected via an actuated dip-lubricated friction clutch to the clutch input shaft, wherein the friction clutch between a fixed on a main hub Outer disk carrier and an inner disk carrier lying disc set comprises, wherein the disk set is operated for coupling directly or indirectly via at least one piston of a hydraulic actuator, wherein at least one piston separates a working space of a compensation chamber, the piston with its radially outer guide contour on a cylindrical portion a piston attached to the main hub Ausgleichsraumbegrenzungswandung is sealingly guided and wherein the piston with its radially inner guide contour in the Main hub is sealingly guided.

From EP 1 568 906 A1, a double clutch with adjacently arranged, hydraulically engaging disk sets is known in which there is one working space and one equalizing space per piston. The respective piston separates the working space from the equalization chamber. The inlet opening of the working space is located in this case - seen in the radial direction relative to the theoretical axis of rotation of the coupling - on a smaller radius than the overflow opening of the compensation chamber. This has the consequence that the radial filling level of the compensation chamber is lower than the radial filling height of the working space. Thus, the filling of the compensation chamber can not compensate for the centrifugal force of the working space filling.

The object of the present invention is to develop a coupling system in which, in at least one of the clutches, the effect of the working space filling under the influence of centrifugal force, which obstructs the disengagement of the clutch, is minimized.

This object is achieved with the features of claim 1. For this purpose, the piston with its radially inner guide contour is sealingly guided on a cylinder ring arranged on the main hub. The radially inward compensation chamber boundary wall protrudes into the installation space of the cylinder ring. The Ausgleichsraumbegrenzungs- wall has at least one overflow recess whose shortest distance to the coupling center line is smaller than the distance of the guide surface of the cylinder ring to the coupling centerline.

In conventional wet clutch transmissions, in particular dual-clutch transmissions, the work spaces of the pistons are in rotation when the drive motor is running. As a result, in addition to the static working pressure, a fluid oil pressure corresponding to the rotating oil column is created in these work spaces. This hinders a quick release of the corresponding clutch. A compensation chamber, which is adjacent to the piston and filled only with centrifugal oil, acts against the level of fluid pressure present in the working space. conditions, provided that the compensation chamber is located on the side of the piston on which the working space is not arranged.

The object of the invention is, in at least one coupling of the coupling system, the working space and the

Compensation space to reduce the Fliehöleinflusses match. This results in a space-saving, radially nested arrangement of working space and compensation chamber. The nesting ensures that the necessary centrifugal oil balance is ensured. For this purpose, the working space of the annular piston projects into the compensation chamber. In addition, an overflow of the compensation chamber is located radially almost at the same height as the inner annular piston seal.

Further details of the invention will become apparent from the subclaims and the following description of a schematically illustrated embodiment:

Figure 1: partial longitudinal section through a double clutch;

Figure 2: Figure 1 with further details.

1 shows a double clutch with two dip-lubricated and -cooled friction clutches 50, 150. These non-positive clutches have two radially successively arranged disk packs 55, 155. Accordingly, the first disk set 55 sits on a larger radius than the second 155. The two clutches 50th , 150 are hydraulically closed. Solving the individual

Clutch 50, 150 via spring elements and / or hydraulically via corresponding cylinder-piston units. The spring elements 100, 200 are, for example, mechanical springs, such as coil springs and / or diaphragm springs. This clutch system is usually used in passenger cars. The clutch system sits between a multi-shaft gearbox and the drive motor of the vehicle. The drive motor is usually a gasoline or diesel engine. Between the drive motor and the clutch system, a single or dual mass flywheel 3 is often mounted.

Since the clutch system has a large diameter, it is arranged in the Getriebegehausebereich, which is referred to as bell housing 10.

The engine torque passes from the crankshaft to the flywheel 3, see. Figure 1. The latter sits on a torsionally rigid shaft-hub connection 21 on the clutch input shaft 20, see. Figure 1. Behind the shaft-hub connection 21, the clutch input shaft 20 widened to form a Mitnehmerscheibensitzes 22. The Mitnehmerscheibensitz 22 has a common mounting joint 23 with the drive plate mounted on it 30. The radius of the assembly joint 23 is greater than 45% greater than the effective diameter of the shaft-hub connection 21st

The e.g. Deep-drawn drive plate 30 is rotationally rigidly connected to a first outer disk carrier 40, which in turn is rotationally rigidly connected to a second outer disk carrier 140. The outer disk carriers 40, 140 have two annular disk support portions 58 and 158. The first outer disk carrier 40 is fixed to a main hub 47. The combination of clutch input shaft 20, drive plate 30, outer plate carrier 40,

140 and main hub 47 rotate at engine speed. These parts 20, 30, 40, 140, 47 are in permanent engagement with the crankshaft of the drive motor.

The clutch input shaft 20 has a central bore 24 in which a first gearbox input is stored rollingly supported. shaft 51 is stored. On this transmission input shaft 51, a first Lamellentragerflansch 53 is arranged via a shaft-hub connection 52. At Lamellentrager- flange 53, a first cup-shaped plate carrier 54 is welded. The fins 56, 57 of the first clutch 50 are arranged between the first disk carrier 54 and the outer disk carrier section 58 of the first outer disk carrier 40. In this case, external disks 56 engage in a form-locking manner in the profiling of the outer disk support section 58. The outer disks 56 are mounted torsionally stiff but slidably displaceable on this disk support portion 58. The seated between the outer disk 56 inner plates 57 are connected in a similar manner with the profiling of the first inner disk carrier 54.

The first outer disk carrier 40 forms, together with the main hub 47, a compensating ring cylinder 45. According to FIG. 1, a cylinder outer wall 48 which is substantially U-shaped in the partial cross section is arranged laterally offset laterally offset from the compensating ring cylinder 45 on the main hub 47. Between the cylinder outer wall 48 and the compensating ring cylinder 45, a molded from deep-drawn sheet, the first annular piston 61 is arranged. The annular piston 61 has a piston section 62 and a force transmission section 67. Between the piston section 62 and the cylinder outer wall 48 there is a first working space 80.

This working space 80 is pressurized with pressure oil to press the power transmission section 67 against the first plate pack 55. For this purpose, the power transmission section 67 engages via fingers 68 into the interior 46 of the first outer disk carrier 40. When the first clutch 50 is actuated, the clutch input shaft 20 is moved over the first outer disk carrier 40 and the first inner disk. Slider 54 is connected to the first transmission input shaft 51. One of the gear wheels arranged on this shaft 51 then meshes with a gear wheel on the transmission output shaft in a force-transmitting manner. The gear wheels and the transmission output shaft are not shown in FIG.

Between the piston portion 62 and the compensating ring cylinder 45 of the first outer disk carrier 40 is a first, oil-filled compensation chamber 90th

Between the force transmission section 67 and the first outer disk carrier 40, the diaphragm spring 100 is seated as an elastic return element. It releases the fingers 68 from the first disk set 55 when the first working space 80 is depressurized.

In the main hub 47 is a second transmission input shaft 151, e.g. stored over two needle bearings. This transmission input shaft 151 embodied as a hollow shaft surrounds the first transmission input shaft 51 at least in regions. At the front end of the shaft oriented towards the clutch input shaft 20 there is a shaft-hub connection 152, via which a second disk carrier flange 153 is rotationally fixed on the second transmission input shaft 151 is arranged. The inner disk carrier 154 of the second clutch 150 is fastened to the disk carrier flange 153.

Between this second inner disk carrier 154 and the first inner disk carrier 54, an inner disk carrying section 158 of the second outer disk carrier 140 is arranged. It is welded to the first outer disk carrier 40. The second inner disk carrier 154 and the second outer disk carrier 140 fix the second disk set 155 in a known manner. Within the installation space of the second inner disk carrier 154, a compensation space limiting wall 191 fastened to the main hub 47 is arranged. The boundary wall 191 has the shape of a second compensation chamber 190 surrounding on three sides of the annular channel

Between the compensation chamber 190 and the first outer plate carrier 40, a second annular piston 161 is arranged. The annular piston 161, which is divided into a piston section 162 and an actuating section 167, prints with the actuating section 167 on engagement with the second disk set 155 during engagement.

The piston portion 162 terminates a second working space 180, which is formed by the first outer disk carrier 40 and a cylinder ring 181. In this case, it is sealed against both components 40, 181 by means of lip seals. The piston portion 62 of the first annular piston 61 has comparable seals. The cylinder ring 181 is also fixed to the main hub 47. The annular piston 161 is also sealed off from the compensation chamber 190.

When the second clutch 150 is actuated, the second outer disk carrier 140 is connected to the second inner disk carrier 154 when the first clutch 50 is open. The engine torque is thus transmitted to the second transmission input shaft 151. Corresponding gear wheels conduct the rotational movement in a torque-changed manner to the transmission output shaft (not shown) which drives the drive train.

In the second compensation chamber 190, a plurality of spring elements 200, for example in the form of helical compression springs arranged. They are cut off between the second annular piston 161 and the boundary wall 191. Over the spring elements 200 of the annular piston 161 is lifted when loosening the second clutch 150 from the corresponding disk set 155.

FIG. 2 shows u.a. This compensation chamber 190 is bounded by the Ausgleichsraumbegrenzungs- wall 191, the cylinder ring 181 and guided between the two latter components piston portion 162 of the annular piston 161.

The gutter- or channel-like Ausgleichsraumbegrenzungswandung 191 annularly surrounds the main hub 47 carrying them. Their opening cross-section oriented to the left according to FIGS. 1 and 2 is closed, for example, approximately 77% by the piston section 162 of the annular piston 161. The remaining cross-sectional area is covered by the cylinder ring 181.

The Ausgleichsraumbegrenzungswandung 191 has, for example, two cylindrical areas. The first is an outer guiding region 192, on the inner wall 193 of which the piston section 162 slides sealingly along. The second is a ring portion 194 disposed near the main hub 47 and having a plurality of overbias 195.

The compensation chamber 190 is filled and emptied via the overflow bores 195. The emptying takes place when the second coupling 150 is actuated. The hydraulic oil 4 displaced via the overflow bores 195 through the annular piston 161 flows in a largely radial direction into a gap space 5 located between the compensation chamber boundary wall 191 and the second inner disk carrier 154. It serves, inter alia, for cooling the disk packs 55, 155. The cylinder ring 181 has a cylindrical guide portion 182 and a double-angled flange portion 184 supporting it. The latter is rotationally rigid together with the balance space limiting wall 191

Main hub 47 attached. The entire - radially between the clutch center line 9 and the cylinder ring 181 located - cavity is referred to as space of the cylinder ring 181.

The guide region 182 of the cylinder ring 181 has on its outer contour a Fuhrungsflache 183 on which the annular piston 161 - the working chamber 180 and the compensation chamber 190 separating - slidably along.

In compensation chamber 190 is a standing under centrifugal oil quantity. The large radius 197 of the compensation chamber 190 is predetermined by the outer guide surface 193. The small radius 198 of the compensation chamber 190 determine the edges of the overflow recesses 195 oriented toward the coupling center line 9. The rotating effective oil column of the compensation chamber 190 extends approximately from the small radius 198 to the large radius 197.

The working space 180 of the second annular piston 161 is bounded radially outward by a piston-side guide surface 165. A seal 49 arranged in the outer disk carrier 40 slides along it. The radius 187 of this guide surface 165 is smaller than the large compensation space radius 197.

The radially inner boundary of the working space 180 is located in the flange portion 184 of the cylinder ring 181. The pressure oil supply of the working space 180 takes place at the level of the radius 188. The rotating effective Oil column of the working space 180 thus extends approximately from the small radius 188 to the large radius 187th

By a specific choice of the radius 198, the effective on the surface of the piston portion 162 between radius 189 and 197 rotational pressure of the rotating oil column, which forms between radius 198 and 197 in the compensation chamber 190, vote. As a result, in the working space (180) resulting rotational pressure, which can lead to an unwanted closing of the clutch, to 100% or more.

Furthermore, it is possible for certain applications to provide a compensation of the rotational pressure according to the invention only to a certain, desired amount less than 100%.

LIST OF REFERENCE NUMBERS

2 gear compartment, transmission passage

3 dual-mass flywheel, flywheel 4 hydraulic oil, pressure oil

5 gap space

9 coupling center line

10 Transmission housing, bell housing 11 Partition

20 clutch input shaft

21 shaft-hub connection

22 Driving disc seat 23 Mounting joint

24 hole, central

30 drive plate

40 first outer disk carrier of the outer clutch

45 balancing ring cylinder, wall of the

compensation Räumes

46 Interior 47 Main hub

48 cylinder outer wall

49 seal

50 first friction clutch, outer clutch 51 first transmission input shaft

52 shaft-hub connection

53 first plate carrier flange

54 first inner disk carrier

55 plate pack 56 outer plates

57 inner fins 58 Lamellentragabschnitt, outside

60 first actuator

61 first ring piston, piston

62 piston section

67 power transmission section

68 fingers

80 first working space

90 first equalization room

100 spring element, return spring, diaphragm spring

140 second outer disc carrier of the inner clutch

150 second friction clutch, inner clutch

151 second transmission input shaft 152 shaft-hub connection

153 second plate carrier flange

154 second inner disk carrier

155 plate pack

156 outer fins 157 inner fins

158 Lamellentragabschnitt, inside

160 second actuator

161 second annular piston, piston 162 piston section

163 Guide contour, lying radially on the outside

164 Guide contour, radially inward

165 Guide surface, cylindrical, outboard

167 operating section 180 second working space

181 cylinder ring

182 leadership area

183 guide surface, cylindrical, lying inside

184 flange area

187 working space radius, large

188 working space radius, small

189 Distance from (9) to (183), radius

190 second equalization room

191 expansion chamber boundary wall

192 guide area, outside lie section

193 guide surface, cylindrical, outboard

194 Ring area, cylindrical, inside area

195 overflow recesses, bores

197 Compensation space radius, large

198 compensation space radius, small

200 spring elements, return springs, coil springs

Claims

claims 1. clutch system for motor vehicle drives with a clutch input shaft (20) and at least one ner transmission input shaft (51, 151) which are arranged concentrically to a clutch center line (9), - Wherein the transmission input shaft (51, 151) via at least one operable friction clutch (50, 150) with the clutch input shaft (20) is connected - wherein the single friction clutch (50, 150) between a on a main hub (47) fixed to Oßenlamellenträger (40, 140) and an inner disk carrier (54, 154) lying disk set (55, 155), - wherein the disk set (55, 155) for coupling directly or indirectly via at least one piston (61, 161) of a hydraulic actuator (60, 160) is actuated, - wherein at least one piston (161) separates a working space (180) from a compensation space (190), - Wherein the piston (161) with its radially outer guide contour (163) on a cylindrical portion (192) of a main hub (47) fixed Ausgleichsraumbegrenzungswandung (191) is sealingly guided, and - Wherein the piston (161) with its radially inner guide contour (164) in the region of the main hub (47) is sealingly guided, characterized in that - the Ausgleichsraumbegrenzungswandung (191) at least one overflow recess (195) whose shortest distance (198 ) to the coupling agent never (9) is smaller than the distance (189) of a radially inward, in the region of the main hub (47) arranged Fuhrungsflache (183) for Kupplungsmit- tellime (9). 2. Clutch system according to claim 1, characterized in that it has at least two transmission input shafts (51, 151), each transmission input shaft (51, 151) being connected to a fluid-lubricated and cooled friction clutch (50, 150) and each friction clutch ( 50, 150) comprises at least one disc pack (55, 155). 3. Coupling system according to claim 1, characterized in that the piston (161) with its guide contour (164) is sealingly guided on a cylinder ring (181) arranged on the main hub (47). 4. Coupling system according to claim 1, characterized in that a radially inner region (194) of the Ausgleichsraum- grenzungswan- tion (191) projects into the space of the cylinder ring (181). 5. Coupling system according to claim 1, characterized in that the Uberlaufausnehmungen (195) are radially arranged openings. 6. Coupling system according to claim 1, characterized in that the cylinder ring (181) in the axial direction to above the middle of the compensation space (190) protrudes into these (190). 7. Coupling system according to claim 1, characterized in that the overflow recesses (195) open into a gap space (5) which leads to the disk packs (55, 155) and is located between the equalizing space boundary wall (191) and an inner disk carrier (154) ,