Patent ID: 12188524

DETAILED DESCRIPTION

FIG.1shows a longitudinal section running along an axial direction through an exemplary embodiment of a torque distribution device1according to the disclosure in a schematic representation.FIG.2is an enlarged view of the upper right quarter ofFIG.1. The torque distribution device1is part of a motor vehicle not shown in detail and is used to transmit the drive torque generated by a motor to the two wheels of a common axle according to an adjustable ratio.

The torque distribution device1includes a rotor carrier2that is U-shaped as viewed in a longitudinal section, which, like almost all components of the torque distribution device1, is designed to be ring-shaped. The rotor carrier2is connected or can be connected to a torque-introducing shaft3or input shaft, for example by means of a welded connection. As indicated by the dashed line inFIG.1, the shaft3can also be provided at other points on the torque distribution device1. In any case, the shaft3is coupled to the rotor carrier2so that the introduced torque is transmitted to the rotor carrier2. The rotor carrier2and the shaft3are rotatably mounted about a rotation axis16.

The torque distribution device1also includes two separate clutch devices4,5according to the disclosure, which are designed as multiple disc clutches. Each clutch device4,5includes an axially displaceable outer disc pack6,7, which is connected in a non-rotatable manner to the rotor carrier2via a toothing connection. Each clutch device4,5includes an axially displaceable inner disc pack8,9, each of which is coupled in a non-rotatable manner to an inner multiple disc carrier10,11via a toothing connection and can be coupled or is coupled to a separate output shaft14,15via a hub flange12,13. For this purpose, each hub flange12,13has an axial toothing17,18which meshes with an axially extending outer toothing of the output shafts14,15. The output shafts14,15, as well as the rotor carrier2together with the shaft3, are rotatable about the rotation axis16. The outer and inner disc packs6,8and7,9each engage in one another and each form a common disc pack.

The clutch devices4,5each include a separate actuation device19,20, via which the respective clutch device4,5can be actuated. The clutch devices4,5or actuation devices19,20can be controlled separately so that the torque introduced by means of the shaft3can be selectively guided from the rotor carrier2to the output shafts14,15.

In the following, details regarding the actuation device20are explained with reference toFIG.2, in which the corresponding section of the torque distribution device1is shown enlarged. However, the aspects explained in this context apply equally to the mirrored actuation device19or clutch device4.

The clutch device5or actuation device20includes a primary piston21and a secondary piston22. A stationary retaining element23is provided on the rotor carrier2, on which the pistons21,22are arranged in an axially displaceable manner. The primary piston21rests with its radially outer end against the outer disc pack7or faces it, so that the outer disc pack7can be pressed axially against the inner disc pack9by means of the primary piston21in order to bring the disc packs7,9into frictional contact or frictional engagement. The primary piston21has an annular groove-like section located radially on the inside, in which further components of the actuation device20or clutch device5, which are discussed in detail further below; are accommodated in a space-saving design for the clutch device5.

A wall or section of the primary piston21delimits a primary pressure chamber24. A pressure medium such as a hydraulic oil can be introduced into the primary pressure chamber24and pressurized, so that when pressure is applied to the pressure medium, the axial displacement previously described and thus the pressure effect of the primary piston21on the disc packs7,9is effected.

The secondary piston22delimits a secondary pressure chamber25, into which a pressure medium such as a hydraulic oil can also be introduced and pressurized. The primary piston21and the secondary piston22are coupled to one another via a spring element26, which in the present case is a bellows27. Here, the secondary piston22and the spring element26are an integral component. By way of example, the integral component is a correspondingly formed, integral sheet metal part which forms both the bellows27and the secondary piston22. The practically cylindrical or ring-shaped bellows27delimits the primary pressure chamber24outwards in the radial direction. The bellows27is correspondingly designed to be fluid-tight and is fastened to the primary piston21by means of a fluid-tight connection. The bellows27is fastened to the primary piston21, so that when the secondary piston22moves in a direction away from the primary piston21, the primary piston21can also move the secondary piston away from the disc pack.

In order to seal the primary pressure chamber24and the secondary pressure chamber25with respect to the axial movement of the primary piston21and the secondary piston22along the retaining element23, the pistons21,22each slide on a sealing element39arranged on the retaining element23, which is in each case designed as a sealing ring.

The secondary piston22includes a radial, disc-like secondary piston section28and an axial, cylinder-like secondary piston section29adjoining it, wherein the bellows27is a component of the axial secondary piston section29. Viewed in cross-section, the secondary piston22is L-shaped due to the sections28,29. The bellows is arranged at the end of the axial secondary piston section29opposite the radial secondary piston section28. Alternatively, the spring element26or the bellows27can form the axial secondary piston section29.

The retaining element23has a support flange30extending in the radial direction, which extends between the primary piston21and the secondary piston22. The support flange30is engaged around by the cylindrical axial secondary piston section29, so that the axial secondary piston section29slides along the radial end of the support flange30. A support flange sealing element31, in the present case a sealing ring made of an elastomer mounted on the support flange, is arranged at the radial end of the support flange30for fluid-tight sealing of the primary pressure chamber24towards the secondary piston22or the secondary piston section29.

The secondary pressure chamber is delimited by a secondary pressure chamber delimiting flange32, which is L-shaped in cross-section and which is stationary with respect to the axially displaceable pistons21,22as well as fastened to the retaining element23. The radial secondary piston section28has an axially open annular groove33delimiting the secondary pressure chamber25, into which the secondary pressure chamber delimiting flange32axially engages. During the axial displacement of the secondary piston22, the secondary pressure chamber delimiting flange32slides along a surface of the annular groove33. A delimiting flange sealing element34is provided in order to seal the secondary pressure chamber25, which rests against the secondary piston in the annular groove33. The delimiting flange sealing element34is also a sealing ring made of an elastomer.

As can be seen in particular fromFIG.2, the secondary pressure chamber delimiting flange32has a radial section in which it extends in a disc-like manner away from the retaining element23in the radial direction. The radial section is followed by a cylindrical axial section, via which the secondary pressure chamber delimiting flange32engages in the cylinder-like annular groove33, which is also delimited radially outwards. The secondary pressure chamber25is delimited at one axial end by the annular groove33of the secondary piston22and at the other axial end by the secondary pressure chamber delimiting flange32. With regard to the radial direction, the secondary pressure chamber25is delimited both by an axial wall section of the annular groove33and by the axial section of the secondary pressure chamber delimiting flange32.

In the clutch device5, a further spring element35is also provided, which is supported on the one hand on the support flange30and on the other hand on the secondary piston22, specifically on the radial secondary piston section28adjacent to the annular groove33. In the present case, the further spring element35is a coil spring that extends around the rotation axis16with respect to its circumference.

In order to distribute the pressure medium into the pressure chambers24,25, a pressure medium distribution unit36is provided, which is partially arranged within or in the region of the retaining element23. The pressure medium distribution unit36includes a primary pressure medium supply line37, by means of which the primary pressure chamber24can be supplied with pressure medium. Furthermore, the pressure medium distribution unit36includes a secondary pressure medium supply line38, by means of which the secondary pressure chamber25can be supplied with pressure medium. The pressure medium distribution unit36includes valves, which are not shown in detail and can be controlled by means of a control device, so that the pressure chambers22,23can be pressurized. The supply lines37,38can be supplied with pressure medium independently of one another and, as a result, the pressure chambers37,38can also be pressurized independently of one another.

The function of the torque distribution device1or the clutch device5is explained below, wherein the function of the clutch device4is of course the same. First, the method by means of which the clutch device5is transferred from a release position to a sensing position is described. The sensing position is the position in which the clutch device5is closed. i.e., the torque can be transmitted from the input shaft3to the output shaft15, depending on which clutch device is actuated, by means of friction between the outer disc pack7and the inner disc pack9caused by the pressure force of the primary piston21. The release position is the position in which this friction is canceled by spacing apart the primary piston21from the disc pack.

For this purpose, it is provided that, starting from a situation in which both pressure chambers24,25are not pressurized, pressure is first applied to the secondary pressure chamber25, so that the secondary piston, with reference toFIG.2, moves to the left and displaces the primary piston21to the left, so that the latter comes into contact with the outer disc pack9. This results in a very rapid transfer of the primary piston21to the disc pack, so that the so-called release clearance is overcome very quickly. In this regard, the secondary piston runs against the support flange30, which serves as an axial stop. Subsequently or simultaneously, pressure is applied to the primary pressure chamber24, which ultimately effects the pressure force of the primary piston21against the disc pack in order to compress the latter. At the same time, the bellows27connected to the primary piston is tensioned, as the primary piston21moves while the secondary piston28is supported on the support flange30.

The multiple disc clutch5is returned from the sensing position to the release position by depressurizing both pressure chambers24,25with respect to the pressure medium arranged therein in each case. In this regard, the spring element26, i.e., the bellows27, which is subjected to tensile loading, directly causes the primary piston21to move away from the disc pack, so that it is immediately relieved. This effect is reinforced by the further spring element35, which also moves the secondary piston22to the right with reference toFIG.2, so that a low-hysteresis control behavior is also achieved with regard to the opening of the clutch device5.

REFERENCE NUMERALS

1Torque distribution device2Rotor carrier3Shaft4Clutch device5Clutch device6Outer disc pack7Outer disc pack8Inner disc pack9Inner disc pack10Inner multiple disc carrier11Inner multiple disc carrier12Hub flange13Hub flange14Output shaft15Output shaft16Rotation axis17Axial toothing18Axial toothing19Actuation device20Actuation device21Primary piston22Secondary piston23Retaining element24Primary pressure chamber25Secondary pressure chamber26Spring element27Bellows28Secondary piston section29Secondary piston section30Support flange31Support flange sealing element32Secondary pressure chamber delimiting flange33Annular groove34Delimiting flange sealing element35Spring element36Pressure medium distribution unit37Primary pressure medium supply line38Secondary pressure medium supply line