Release bearing with oil guide contour and clutch assembly with the release bearing

Abstract

A release bearing 1 for a clutch assembly 18 is proposed, comprising an inner ring 2 and an outer ring 3, which define a rolling element space 4 in a radial direction 101 with respect to an axis of rotation 100, and comprising a plurality of rolling elements 5, which are arranged rolling between the inner ring 2 and the outer ring 3 in the rolling element space 4, wherein the inner ring 2 has an oil guide contour 11, which is designed to direct an oil volume flow 103 in the direction of the rolling element space 4 when the inner ring 2 is rotated in a direction of rotation 104.

Description

[0001] The invention relates to a release bearing for a clutch arrangement having the features of the preamble of claim 1. Furthermore, the invention relates to a clutch arrangement with the release bearing.

[0002] Concentric slave cylinders (CSC) are typically used in both hybrid and purely electric vehicle drive systems. These serve, for example, to separate the electric motor from the combustion engine or to change gears. Such slave cylinders essentially consist of an annular housing and an annular piston that can be axially displaced within the annular housing. When a master cylinder is actuated, the annular piston acts on a clutch-side release bearing, thus actuating, in particular engaging, the clutch.

[0003] The document DE 10 2020 109 989 A1 discloses a clutch device for a motor vehicle, with a shaft, wherein the shaft extends axially, with a clutch section, wherein the clutch section is arranged coaxially to the shaft and rotates with the shaft, wherein axial and radial forces act on the shaft and / or on the clutch section during rotation of the shaft, wherein at least the radial forces can cause a radial offset of the clutch section and / or a misalignment of the clutch section and / or the shaft, and with a release bearing, wherein the release bearing is axially movable for transmitting an actuating force to the clutch section, wherein the release bearing is guided through the shaft and / or on the shaft in the radial direction to compensate for the axial offset and / or the misalignment.

[0004] It is an object of the present invention to propose an actuating device which is characterized by high operational reliability, in particular at high speeds.

[0005] This object is achieved by a release bearing having the features of claim 1 and a clutch arrangement having the features of claim 9. Preferred or advantageous embodiments of the invention emerge from the subclaims, the following description and the attached figures.

[0006] The subject matter of the invention is a release bearing designed and / or suitable for a clutch assembly. In particular, the release bearing serves to transmit an actuating force from a slave cylinder to a clutch device of the clutch assembly. The release bearing has the function of decoupling the transmission of a rotational movement from the clutch device to the slave cylinder. For this purpose, the release bearing is preferably designed as a rolling bearing, preferably an angular contact ball bearing.

[0007] The release bearing has an inner ring and an outer ring. In particular, the inner ring and the outer ring are arranged coaxially and / or concentrically with a rotational axis. Preferably, the outer ring is motion-coupled to the slave cylinder, and the inner ring is motion-coupled to the clutch device. In other words, the inner ring forms a rotating part and the outer ring a stationary part of the release bearing. For example, the outer ring can be designed as a sheet metal component and the inner ring as a solid component.

[0008] The inner ring and the outer ring define a rolling element chamber in a radial direction relative to the rotational axis. In particular, the rolling element chamber is designed to extend circumferentially around the rotational axis. The rolling element chamber is preferably open axially on one or both sides relative to the rotational axis. When the release bearing is arranged in the clutch assembly, preferably in a wet chamber, an oil, in particular a lubricating and / or cooling oil, can thus enter the rolling element chamber.

[0009] The release bearing has a plurality of rolling elements, which are arranged, preferably in single or multiple rows, in a rolling-contact manner between the inner ring and the outer ring in the rolling-element space. For this purpose, the inner and outer rings each have at least one or exactly one raceway for a row of rolling elements. The release bearing particularly preferably has a cage for guiding the rolling elements.

[0010] Within the scope of the invention, it is proposed that the inner ring have an oil guide contour designed to generate a volumetric oil flow specifically toward the rolling element chamber upon rotation of the inner ring in one direction of rotation. In particular, the oil guide contour serves to convey oil radially within the inner ring and / or in contact with the inner ring radially and axially with respect to the axis of rotation into the rolling element chamber, preferably to the contact points of the rolling elements with the raceways. The oil guide contour preferably forms an integral component of the inner ring.

[0011] The invention is based on the finding that release bearings can heat up considerably under load, i.e. under the influence of a high actuating force (> 4000 N) and a high speed (> 10000 rpm). In order to dissipate the resulting heat and prevent the release bearing from overheating, an appropriate oil volume flow is necessary. Depending on the application, a targeted oil volume flow must be directed directly into the area of ​​the raceways of the release bearing in order to cool this area. During operation of the release bearing, in particular when the inner ring rotates in one direction of rotation, the oil guide contour effects a directed oil volume flow that is specifically directed into the rolling element chamber. This delivers a higher quantity of oil to the rolling contacts, thus improving cooling of the release bearing. In addition, the maximum service life of the release bearing can be considerably extended, and at the same time the operational reliability of the clutch assembly can be increased.

[0012] In a specific embodiment, the oil guide contour is formed or co-formed by a plurality of oil guide vanes distributed over the circumference, which deflect the oil volume flow essentially in the radial direction with respect to the axis of rotation into the rolling element chamber. In particular, the oil guide vanes are aligned in the circumferential direction in such a way that, when the inner ring rotates in the direction of rotation, they convey oil coming from the axial inside essentially radially outwards. In this case, “essentially in the radial direction” is to be understood as meaning that the oil volume flow can flow mainly radially and, if necessary, also circumferentially and / or axially with respect to the axis of rotation into the rolling element chamber. In other words, the oil volume flow changes direction into the rolling element chamber due to the oil guide vanes.An oil guide contour is thus proposed which, when the inner ring rotates, conveys a large part of the oil volume conveyed in the circumferential direction towards the rolling element space.

[0013] In one specific embodiment, the oil guide vanes are each formed by a recess. In particular, the recess is arranged on an axial end face of the inner ring. The recess can be formed by an opening, cutout, or the like. For example, the recesses can be machined. This enables particularly simple and cost-effective production of the oil guide vanes.

[0014] In another specific implementation, the oil guide vanes each have a blade incline acting in the direction of the rolling element chamber. In particular, the blade inclines serve to specifically convey oil into the rolling element chamber when the inner ring rotates in the direction of rotation. The recesses are preferably inclined relative to a radial direction and / or an axial direction of the axis of rotation. The blade incline improves the scooping and pumping action of the oil guide vane in the direction of the rolling element chamber, as the oil is forced into the rolling element chamber along the blade incline as a result of the rotation of the inner ring. In addition, the blade incline promotes the oil supply to the oil guide vanes.

[0015] In a specific further development, it is provided that the blade inclination is formed by at least or exactly one inclined surface rising counter to the direction of rotation and / or in an axial direction with respect to the axis of rotation.

[0016] In particular, the inclined surfaces are each arranged in an axial view with respect to the axis of rotation at a second angle to the axial direction or to a transverse axis. Optionally, in a radial view with respect to the axis of rotation, the inclined surfaces can each be arranged at a first angle to the axial direction or to the axis of rotation. In particular, the transverse axis is arranged at a right angle to the axis of rotation. For example, the first and / or second angle can be more than 10°, preferably more than 30°, in particular more than 50°. In particular, the recess is delimited in the circumferential direction by two inclined surfaces which are aligned parallel and / or in the same direction to one another. A blade inclination is thus proposed which generates a targeted oil volume flow into the rolling element space.

[0017] In an optional embodiment, the oil guide contour is formed or co-formed by an inner cone formed on the inner circumference of the inner ring, which inner cone deflects the oil volume flow essentially in an axial direction towards the oil guide vanes. In particular, the inner cone is oriented in the axial direction such that, when the inner ring rotates in the direction of rotation, it conveys oil coming from the radial inside essentially axially outwards. In this case, “essentially in the axial direction” is to be understood as meaning that the oil volume flow can run primarily axially and, if appropriate, also circumferentially and / or radially with respect to the axis of rotation to the oil guide vanes. In other words, the oil volume flow changes direction towards the oil guide vanes due to the inner cone. An oil guide contour is thus proposed which always directs the oil coming from the inside towards the oil guide vanes when the inner ring rotates.

[0018] In a specific implementation, the inner cone has a conical surface that rises in the axial direction relative to the rotational axis. In particular, the conical surface is inclined relative to the axial direction or the rotational axis. In particular, the conical surface has a constant pitch angle relative to the axial direction or the rotational axis. In other words, the conical surface is arranged in a longitudinal section at an angle to the axial direction or the rotational axis.

[0019] For example, the angle can be more than 1°, preferably more than 5°, and especially more than 10°. Thus, a conical surface is proposed that specifically generates an oil volume flow toward the oil guide vanes.

[0020] In another specific embodiment, the recesses for forming the oil guide vanes are incorporated into the conical surface. In other words, the conical surface is interrupted by the recesses. In particular, the recesses are located at the ends of the conical surface and / or outside the raceway of the inner ring. As the inner ring rotates, the oil is always conveyed through the conical surface in the direction of the recesses and carried along by the oil guide vanes in the circumferential direction.

[0021] Another subject matter of the invention relates to a clutch assembly with the release bearing, as already described above. In particular, the clutch assembly is designed and / or suitable for a drive train of a vehicle. The drive train can be a purely electric or hybrid drive train. The clutch assembly comprises a clutch device, a slave cylinder, a first and a second shaft, wherein the slave cylinder is operatively connected to the clutch device via the release bearing.

[0022] The clutch device can be designed as a separating clutch, also referred to as a K0 clutch. In particular, the separating clutch serves to interrupt a drive torque between the internal combustion engine and the electric machine in the hybrid drive train or to change gears in the electric drive train. The clutch device is preferably designed as a friction clutch, preferably a friction-disk clutch. For this purpose, the clutch device can have an outer disk carrier connected in a rotationally fixed manner to one shaft and an inner disk carrier connected in a rotationally fixed manner to the other shaft, wherein the outer disk carrier carries a plurality of, preferably at least two, outer disks and the inner disk carrier carries a plurality of, preferably at least two, inner disks, which engage with one another in a frictionally locked manner when the clutch device is in the closed state.

[0023] In particular, the slave cylinder serves to transmit an actuating force to the clutch device in order to open or close the clutch device. The slave cylinder is preferably designed as a concentric slave cylinder, also known as a "concentric slave cylinder (CSC)", which essentially comprises an annular piston and an annular housing. The annular piston and the annular housing are preferably arranged coaxially and / or concentrically with respect to the rotational axis of the release bearing. The annular housing preferably has a central through-opening, in particular a bore, through which at least one of the shafts can be passed when the slave cylinder is installed.

[0024] Optionally, the actuating device comprises a pressure pot, wherein the inner ring is supported at least axially with respect to the main axis on an inner diameter of the pressure pot, so that the actuating force can be transmitted from the annular piston to the pressure pot via the release bearing. The pressure pot can be supported axially with respect to the main axis on one of the inner or outer plates to transmit the actuating force.

[0025] In particular, the two shafts can be connected to one another in a rotationally fixed manner via the clutch device. Preferably, the two shafts are connected to one another in a rotationally fixed manner when the clutch device is closed. Particularly preferably, the two shafts are arranged coaxially and / or concentrically with respect to the rotational axis of the release bearing. Specifically, in one installed position of the release bearing, at least one of the two shafts passes through the inner ring, with the inner ring being arranged radially spaced from the shaft.

[0026] In a further specific embodiment, it is provided that the first and / or the second shaft each have at least one oil supply opening which opens radially inside the inner ring and is designed and / or suitable for supplying oil to the inner ring. In other words, the at least one oil supply opening opens radially inside the inner ring. In particular, the oil supply opening provides an oil volume flow which is distributed within the clutch arrangement by the inner ring. The release bearing is particularly preferably arranged in a wet space of the clutch arrangement. In particular, the first and / or the second shaft can have a plurality of oil supply openings which are spaced apart and / or evenly distributed in the axial direction and / or in the circumferential direction with respect to the axis of rotation. The oil supply opening enables a direct supply of oil to the inner ring, thus further improving the cooling of the release bearing.

[0027] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show: Fig. 1 a sectional view of a release bearing along its axis of rotation; Fig. 2 a perspective view of the release bearing from Fig. 1; Fig. 3 a sectional view of a clutch arrangement with the release bearing from Fig. 1.

[0028] Fig. Figure 1 shows a release bearing 1 in a sectional view along its rotational axis 100 as one embodiment of the invention. The release bearing 1 is designed as an angular contact ball bearing which is designed and / or suitable for absorbing radial and axial forces with respect to the rotational axis 100.

[0029] The release bearing 1 has an inner ring 2 and an outer ring 3, which radially define a rolling element chamber 4 with respect to the rotational axis 100. The rolling element chamber 4 is open axially on both sides with respect to the rotational axis 100. For example, the inner ring 2 is formed as a solid component and the outer ring 3 as a sheet metal component.

[0030] The release bearing 1 has a plurality of rolling elements 5 arranged in a rolling element row, which are arranged in the rolling element chamber 4 between the inner ring 2 and the outer ring 3. For this purpose, the inner ring 2 and the outer ring 3 each have a raceway 8, 9, on which the rolling elements 5 roll, guided in a cage 7. The rolling elements 5 are designed as balls.

[0031] The outer ring 3 has an outer ring flange 10, which is directed outward in a radial direction 101 relative to the rotation axis 100. The outer ring flange 10 is designed as an annular flange that surrounds the main axis 100. For example, the outer ring 3 forms a stationary part of the release bearing 1, and the inner ring 2 forms a rotating part of the release bearing 1.

[0032] The inner ring 2 has an oil guide contour 11 on its inner circumference, which is designed to convey an oil, e.g., a lubricating oil, toward the rolling element chamber 4 and thus into a contact area of ​​the rolling elements 5 with the raceways 8, 9 upon rotation of the inner ring 2. The oil guide contour 11 is formed for this purpose by an inner cone 13 formed on the inner circumference of the inner ring 2 and a plurality of oil guide vanes 12 distributed in the circumferential direction.

[0033] During rotation of the inner ring 2, an oil volume flow 103 coming from the inside is deflected by the inner cone 13 essentially in an axial direction 102 relative to the axis of rotation 100 in the direction of the oil guide vanes 12 and is deflected by the oil guide vanes 12 essentially in the radial direction 101 into the rolling element space 4.

[0034] For this purpose, the inner cone 13 has a conical surface 14 that rises in the axial direction 102 and is inclined at an angle of, for example, less than 5° relative to the rotation axis 100. This ensures that the oil volume flow 103 is reliably directed to the oil guide vanes 12 upon rotation of the inner ring 2.

[0035] As in Fig. 2, the oil guide vanes 12 are each formed by a recess made in the end face of the inner ring 2, which is open in the axial direction 102 and is formed in the conical surface 13. The oil guide vanes 12 each have a blade slope 15 that rises counter to a direction of rotation 104 of the inner ring 2 and is formed by two opposite and mutually parallel inclined surfaces 16, 17. The inclined surfaces 16, 17 have a profile that rises counter to the direction of rotation 104. For example, the inclined surfaces 16, 17 can be inclined at an angle of approximately 45° relative to the radial direction 101.

[0036] Optionally, the inclined surfaces 16, 17 have a gradient that slopes upwards in the axial direction 102. For example, the inclined surfaces 16, 17 can be inclined at an angle of more than 25° relative to the axial direction 102 or the rotational axis 100. This ensures that the oil volume flow 103 is reliably directed into the rolling element chamber 4 upon rotation of the inner ring 2.

[0037] Fig. Figure 3 shows a clutch assembly 18 with the release bearing 1 for a hybrid or electric drive train of a vehicle in a sectional view. The clutch assembly 18 is essentially constructed of a clutch device 19, a slave cylinder 20, and a first and second shaft 21, 22, which are arranged coaxially with respect to one another with respect to a main axis 105. The main axis 105 is defined, for example, by a rotational axis of the shafts 21, 22 and / or the rotational axis 100 of the release bearing 1.

[0038] The slave cylinder 20 is designed as a concentric slave cylinder, abbreviated to CSC, and serves to generate an actuating force, which is transmitted to the clutch device 19 via the release bearing 1 and a pressure pot 23 in order to actuate the clutch device 19. For this purpose, the slave cylinder 20 has an annular piston 24 and an annular housing 25, in which the annular piston 24 is arranged so as to be axially displaceable with respect to the main axis 100. For example, the slave cylinder 20 is hydraulically actuated, wherein a pressure chamber 26 formed between the annular piston 24 and the annular housing 25 is filled with a hydraulic operating medium, e.g., hydraulic oil, in an operating state.

[0039] The clutch device 19 has an outer disk carrier 27 and an inner disk carrier 28, wherein the outer disk carrier 27 carries a plurality of outer disks 29 formed as steel disks, and the inner disk carrier 28 carries a plurality of inner disks 30 formed as friction disks, which are arranged alternately one behind the other. The outer disk carrier 27 is rotationally fixedly connected to the first shaft 21, and the inner disk carrier 28 is rotationally fixedly connected to the second shaft 22. For example, the first shaft 21 can be designed as a hollow shaft, and the second shaft 22 can be designed as a further hollow shaft guided through the hollow shaft.

[0040] When the slave cylinder 20 is actuated, a fluid pressure in the pressure chamber 26 is increased, and the actuating force is applied to the annular piston 24. The annular piston 24 is moved counter to the axial direction 102, and the actuating force is transmitted to the clutch device 3 via the release bearing 1 and the pressure pot 23, whereby the inner and outer plates 29, 30 are pressed together in a frictional engagement to close the clutch device 19.

[0041] The release bearing 1 is arranged radially within the annular piston 24 or concentrically to the annular piston 24, wherein the inner ring 2 is supported on the pressure pot 23 opposite to the axial direction 102 and the outer ring 2 is supported on the annular piston 24 in the axial direction 102 via an intermediate disk 31, e.g., a shim disk. For this purpose, the outer ring 3 is supported on the annular piston 24 via the outer ring flange 10 in order to bridge a radial distance between the annular piston 24 and the release bearing 1.

[0042] The first and second shafts 21, 22 are guided through the inner ring 2 of the release bearing 1, wherein the inner ring 2 is arranged radially spaced from the first and second shafts 21, 22, respectively. The first and second shafts 21, 22 each have at least one oil supply opening 32, 33, via which the oil volume flow 103 is distributed in a wet chamber of the clutch assembly 18. A first oil supply opening 32 of the first shaft 21 opens radially inside the inner ring 2, so that the oil volume flow 103 provided by the first oil supply opening 32 is distributed mainly or largely through the inner ring 2 in the clutch assembly 1. In this case, the oil volume flow 103 is divided into several partial volume flows, as in Fig. 3 schematically indicated, which supply the release bearing 1, the clutch device 19, the slave cylinder 20 and / or other bearing devices 34 with oil. List of reference symbols 1 release bearing 2 inner ring 3 Outer ring 4 Rolling element chamber 5 rolling elements 6 empty 7 cage 8 inner career 9 outer raceway 10 Outer ring flange 11 Oil guide contour 12 oil guide vanes 13 inner cone 14 Conical surface 15 Blade slope 16 Inclined surface 17 additional inclined surfaces 18 Coupling arrangement 19 Coupling device 20 slave cylinders 21 first wave 22 second wave 23 Pressure cooker 24 ring pistons 25 ring housings 26 Printing room 27 outer disc carrier 28 inner disc carrier 29 outer slats 30 inner slats 31 Intermediate disc 32 first oil supply opening 33 second oil supply opening 34 Storage facility 100 axis of rotation 101 Radial direction 102 Axial direction 103 Oil volume flow 104 Direction of rotation 105 Main axis QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 109 989 A1

[0003]

Claims

[1] Release bearing (1) for a clutch arrangement (18), - with an inner ring (2) and an outer ring (3), which delimit a rolling element space (4) in a radial direction (101) with respect to a rotational axis (100), - with a plurality of rolling elements (5) which are arranged in a rolling manner between the inner ring (2) and the outer ring (3) in the rolling element space (4), characterized by that the inner ring (2) has an oil guide contour (11) which is designed to guide an oil volume flow (103) in a targeted manner in the direction of the rolling element space (4) when the inner ring (2) rotates in a direction of rotation (104). [2] Release bearing (1) according to claim 1, characterized by that the oil guide contour (11) is formed or co-formed by a plurality of oil guide vanes (12) distributed over the circumference, which deflect the oil volume flow (103) essentially in the radial direction (101) into the rolling element space (4). [3] Release bearing (1) according to claim 2, characterized bythat the oil guide vanes (12) are each formed by a recess. [4] Release bearing (1) according to claim 2 or 3, characterized by that the oil guide vanes (12) each have a vane slope (15) effective in the direction of the rolling element space (4). [5] Release bearing (1) according to claim 4, characterized by that the blade slope (15) is formed by at least one inclined surface (16, 17) rising counter to the direction of rotation (104) and / or in an axial direction (102) with respect to the axis of rotation (100). [6] Release bearing (1) according to one of claims 2 to 5, characterized by that the oil guide contour (11) is formed or co-formed by an inner cone (13) formed on the inner circumference of the inner ring (2), which deflects the oil volume flow (103) substantially in an axial direction (102) with respect to the axis of rotation (100) to the oil guide vanes (12). [7] Release bearing (1) according to claim 6, characterized bythat the inner cone (13) has a conical surface (13) rising in the axial direction (102). [8] Release bearing (1) according to claims 3 and 7, characterized by that the recesses for forming the oil guide vanes (12) are introduced into the conical surface (13). [9] Clutch arrangement (18) with the release bearing (1) according to one of the preceding claims, with a clutch device (19), with a slave cylinder (20) for actuating the clutch device (19), with a first and a second shaft (21, 22), wherein the slave cylinder (20) is operatively connected to the clutch device (19) via the release bearing (1). [10] Coupling arrangement (18) according to claim 9, characterized by that the first and / or the second shaft (21, 22) have at least one oil supply opening (32, 33) opening radially inside the inner ring (2) for supplying oil.

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