Coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for separably connecting the internal combustion engine to an output element

Abstract

The invention relates to a coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for separably connecting the internal combustion engine to an output element (3) which is coupled to the electric machine, comprising an input element (2), which is to be coupled to the internal combustion engine, a clutch device (8), which is coupled to the input element and to which the output element (3) is coupled, a gear wheel (15), which is to be coupled to the electric meachine, is connected to the output element (3), and supports a plate carrier (11) of the clutch device (8), and a release device (17) comprising a release bearing (20) which can be moved axially from a non-actuated position into an actuated position and is coupled to the clutch device (8), which is actuated into the actuated position in the event of an axial movement of the release bearing (20), said release bearing (20) being pretensioned into the non-actuated position via a spring means (22).

Description

[0001] Coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for detachably connecting the internal combustion engine to an output element

[0002] The invention relates to a coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for detachably connecting the internal combustion engine to an output element which is coupled to the electric machine.

[0003] Such a hybrid drive system is used in motor vehicles and serves the variable, demand-dependent integration of an internal combustion engine into a drive train. The drive system comprises the internal combustion engine and an electric motor as input elements, both of which operate on the same output element, with the electric motor being permanently coupled to the output element, for example, a gear coupled to a transmission shaft. The internal combustion engine can be coupled, if required, via a controllable clutch device, so that the torque supplied by the internal combustion engine is also transmitted to the output element, for example, superimposing the torque supplied by the electric motor. Furthermore, the internal combustion engine can also be decoupled if required, i.e.That is, the mechanical connection to the output element is released via the clutch device and the internal combustion engine is removed from the drivetrain. This is necessary, for example, if only the electric motor is to be used for propulsion, or if the electric motor is switched to generator mode, in which the rotor of the electric motor is driven by the output element in order to recuperate energy via the electric motor.

[0004] In order to variably couple or decouple the internal combustion engine, a clutch device is provided which can be actively opened or closed via an actuating means, whereby the internal combustion engine is coupled or decoupled depending on the switching position of the clutch device. The actuating means is designed as a release device, comprising an axially fixed device part and a device part which is axially movable via an actuating element and on which a release bearing is arranged, which in turn is coupled to the clutch device or an axially movable element of the clutch device, usually a plate carrier of the clutch device, so that on the one hand this device part of the clutch device is rotatably supported via the release bearing, and on the other hand is moved via the axial movement of the release bearing, via which the opening or closing of the clutch device takes place.Such a release device is designed, for example, as a ramp release device, comprising a fixed support disc and a release disc rotatable relative to the support disc, to which the release bearing is coupled. A ramp structure with balls is provided between the support disc and the release disc. When the release disc rotates relative to the support disc, the balls run onto the ramp structure, resulting in an axial displacement of the release disc and the release bearing. This movement is, of course, reversible.

[0005] The problem of the invention is to provide an improved coupling device.

[0006] To solve the problem, the invention provides a coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for detachably connecting the internal combustion engine to an output element that is coupled to the electric machine, comprising an input element to be coupled to the internal combustion engine, a clutch device coupled to the input element and operable via an actuating element, to which the output element is coupled, a gear to be coupled to the electric machine, connected to the output element and carrying a disk carrier of the clutch device, and a release device comprising a release bearing that is axially movable from a non-actuated position into an actuated position, which is coupled to the clutch device and is actuated upon an axial movement of the release bearing into the actuated position,wherein the release bearing is preloaded into the non-actuated position by a spring means.,

[0007] The coupling device according to the invention serves to couple the input element, for example a crankshaft journal, which is or can be connected to the internal combustion engine, with an output element, for example a gear, which is or can be connected to a driven shaft such as a transmission shaft. A clutch device is provided via which a variable coupling and decoupling of the internal combustion engine is possible, wherein the clutch device can be actuated via an actuating element, e.g. in the form of a pressure pot or suitable pressure elements such as bolts or pins for coupling and decoupling. For this purpose, the clutch device is mechanically coupled to the internal combustion engine, which is usually realized via a damper device that is connected to the input element and serves to dampen any rotational irregularities resulting from the operation of the internal combustion engine.The clutch device is connected to the damper device by a first rotating part comprising a plate carrier with plates arranged thereon. A second rotating part comprising another plate carrier with plates arranged thereon is connected to a gear, which in turn is connected to the output element and is also permanently connected to the electric motor or a drive gear driven by the latter, wherein the two gears are preferably coupled via helical gearing. The plate carrier of the clutch device is thus carried by the gear and is connected to it in a rotationally fixed manner, thus also rotating when the gear rotates.The alternating plates form a plate pack, with the plates arranged on the plate carrier coupled to the damper device being outer plates, for example, while the plates arranged on the plate carrier coupled to the gear are inner plates. The plate carrier coupled to the gear is axially displaceable via the release device, which results in the plate pack being able to be axially compressed or opened. When the plate pack is compressed, the internal combustion engine is coupled and an introduced torque is transmitted to the output element, or when the plate pack is opened, the internal combustion engine is decoupled.This axial displacement of the plate carrier is achieved via the release bearing, which is a component of the release mechanism and can be moved axially from a non-actuated position, in which the plate carrier coupled to the release bearing is also in a non-actuated position, to an actuated position, in which the plate carrier is also in an actuated position. Depending on whether the clutch mechanism is a "normally closed" or "normally open" clutch mechanism, the clutch mechanism or the plate pack is closed in the non-actuated position and open in the actuated position, or vice versa.

[0008] According to the invention, the release bearing is preloaded into the non-actuated position by a spring means. In this non-actuated position, the release bearing, which as described is arranged on an axially displaceable component of the release mechanism, is not axially displaced, i.e., is located closely adjacent to the fixed, i.e., axially immovable, component of the release mechanism. In this non-actuated position, the release bearing, and thus the axially displaceable component of the release mechanism, is preloaded by the spring means, i.e., is permanently subjected to an axial force. This advantageously makes it possible to easily hold down the release bearing or the axially movable component, i.e., to actively hold it in the non-actuated position, thereby providing a desired preload to the release mechanism, in particular the ramp mechanism integrated therein.When the movable component is moved axially from the non-actuated position to the actuated position via the actuating element, e.g., a hydraulic actuating cylinder or similar, the spring element is further tensioned, thus building up an increased restoring force, which, when the component of the release mechanism is relieved, actively supports the return of the component. Furthermore, this spring element allows any tolerances between the release bearing and the coupled plate carrier to be bridged. Due to these tolerances and also any wear within the clutch mechanism, a narrow air gap must be set between the release bearing and the plate carrier. This gap is maintained by the spring element on the one hand and bridged on the other.When the release bearing is moved from the non-working position, the release bearing works against the spring means, which dampens the movement and at the same time dampens the run-up of the release bearing against the plate carrier, so that an impact noise when the air gap is overpressed is avoided.

[0009] The spring element itself is advantageously supported on the one hand by the release bearing, i.e., on a ring of the release bearing, which is usually designed as a roller bearing, and on the other hand by the gear itself or the actuating element. These two components are located directly adjacent to each other from an axial perspective, enabling easy integration and mounting of the spring element.

[0010] According to a first variant of the invention, the spring means itself can be an annular spring element. Thus, a spring element is used that extends around the circumference of the components to be coupled, i.e., in particular, the annular gear or the actuating element and the annular release bearing. The annular spring element can be a single disc spring or a disc spring assembly, with the disc spring or disc spring assembly being supported on both components, i.e., in particular, the gear and the release bearing. Alternatively, the annular spring element can also be a spring ring made of an elastic plastic material, for example, an elastomer. This plastic ring can either be arranged on only one of the components to be coupled, i.e., for example, only the gear or only the release bearing, or it can be connected to both components.

[0011] If a disc spring or disc spring assembly is used, the disc spring or disc spring assembly can have one or more protruding fingers on the inner and / or outer circumference, via which it is suspended in receptacles on the release bearing and / or the gear or the actuating element. This creates a mechanical connection that is rotationally fixed in the circumferential direction, so that the disc spring or disc spring assembly is driven, i.e. rotated, when the coupled component(s) rotates due to the finger engagement. This ensures that all components are running at the same speed, preventing slippage and the resulting wear.If a spring washer made of an elastic plastic material is used, it can be glued to one or both components, for example, which also ensures a non-rotatable connection and driving at the same speed.

[0012] According to a second variant of the invention, the spring means can comprise several individual spring elements that are arranged separately at different circumferential positions, for example of the release bearing and / or the gear or the actuating element, depending on where they are attached. For example, three separate spring elements can be provided, which are equidistantly offset by 120° in the circumferential direction, or four separate spring elements offset by 90° in the circumferential direction, although more than four spring elements with a correspondingly adjusted angular offset can also be provided. Unlike the variant with the single annular spring element, these separate spring elements provide point support at several positions. Nevertheless, sufficient axial force can also be applied using such a configuration.

[0013] To secure the separate spring elements, brackets to which the spring elements are attached can be provided on the release bearing and / or the gear or the actuating element. Alternatively, the spring elements can also be attached to the gear, the actuating element, or the release bearing via separate fastening elements. The specific design ultimately depends on the type of spring elements used.

[0014] For example, coil springs or wave springs, but also leaf springs can be used as spring elements.

[0015] If coil springs or wave springs are used, which are essentially cylindrical springs, they are preferably mounted on mounts in the form of protruding pins or inserted into mounts in the form of recesses. These mounts, either on the pins or in the recesses, are conveniently press-fitted, meaning the spring elements are pressed onto or in and thus securely fixed. It is quite understandable that different mount types could be used for attachment to both the release bearing and the gear or the actuating element.

[0016] If leaf springs are used, they are preferably attached using rivets. They are riveted to one or both components, i.e., the gear or the actuating element and / or the release bearing or release bearing ring.

[0017] The invention is explained below using exemplary embodiments with reference to the drawings. The drawings are schematic representations and show:

[0018] Figure 1 is a schematic diagram of a clutch device according to the invention comprising a disc spring arranged between the gear wheel and the release bearing,

[0019] Figure 2 is an enlarged partial view of the integration of the disc spring between the gear and the release bearing of a first variant,

[0020] Figure 3 a detailed view of the integration of the disc spring between the gear and the release bearing of a second variant,

[0021] Figure 4 is a perspective view of a disc spring with fingers projecting on the inner circumference,

[0022] Figure 5 is an enlarged partial view of the integration of the disc spring between the gear and the release bearing by hooking the fingers into the receptacles on the gear,

[0023] Figure 6 is an enlarged partial view of the integration of a disc spring with fingers provided on the outer circumference between the gear and the release bearing by hooking the fingers into receptacles on the gear,

[0024] Figure 7 is a schematic diagram of the arrangement of a coil spring between gear and release bearing,

[0025] Figure 8 is a schematic diagram of the arrangement of a coil spring between the gear and the release bearing of a further variant, Figure 9 is a schematic diagram of the arrangement of a wave spring between the gear and the release bearing,

[0026] Figure 10 is a schematic diagram of the arrangement of a leaf spring between gear and release bearing, and

[0027] Figure 11 is a schematic diagram of the arrangement of a spring ring made of an elastic plastic material between the gear and the release bearing.

[0028] Figure 1 shows a coupling device 1 according to the invention, configured for integration into a hybrid drive device comprising an internal combustion engine (not shown here) and an electric machine (likewise not shown). This coupling device 1 serves for the variably coupling of an input element 2, for example a crankshaft journal, to an output element 3, for example a gearwheel coupled to an output shaft via a toothed connection. In the example shown, the input element 2 is coupled to a damper device 4, wherein the damper device serves to combat any rotational irregularities introduced by the internal combustion engine via the input element 2. For mechanical coupling, the input element 2 is mechanically connected to a housing cover 5 via a screw connection 6.This housing cover 5 is part of the damper device 4, which comprises a plurality of curved coil springs 7 that are connected to the housing cover 4 in a rotationally fixed manner in the circumferential direction. Furthermore, a clutch device 8 is provided, comprising an outer disk carrier 9, via which the clutch device 8 is also coupled to the curved coil springs 7. Outer disks 10 are provided on the outer disk carrier 9. If a torque is introduced via the input element 2, this torque is transmitted via the damper device 4 to the outer disk carrier 9 due to its coupling with the coil springs 7, so that the outer disk carrier 9, together with the outer disk 10, i.e., this first clutch part, also rotates.

[0029] The clutch device 9 further comprises a second clutch part comprising an inner disk carrier 11, on which at least one inner disk 12 is arranged, engaging between the two outer disks 10. The inner disk carrier 11 is axially supported on an abutment 14 via a disc spring 13. On the other side, the disk set is axially supported on a gear 15, to which the inner disk carrier 11 is in turn connected in a rotationally fixed manner in the circumferential direction via fingers 16 extending through openings in the gear 15. Due to this arrangement, the inner disk carrier 11 is axially movable, for which purpose a release device 17 is provided, comprising an axially fixed device part 18 and a device part 19 that is axially movable via an adjusting means.A release bearing 20 is arranged on this, which in turn is arranged directly axially adjacent to the fingers 16 of the inner disk carrier 11, so that the inner disk carrier 11 is also moved axially against the plate spring 13 upon an axial displacement of the release bearing 20 from a non-actuated position to an actuated position. This movement opens, for example, the normally closed clutch device after the disks are moved apart and the frictional engagement between them, which transfers a torque introduced at the input element 2 to the output element 3, is canceled, so that the internal combustion engine is decoupled.If the axial adjustment is canceled again, i.e. the release device 17 is no longer actuated and is returned to the non-actuated position, the plate pack is compressed again via the plate spring 13 and the movable device part 19 together with the release bearing 20 is returned to the non-actuated position.

[0030] The gear 15 has external teeth 21, preferably helical teeth, with which an output element of the electric machine (not shown) is in permanent engagement, i.e. there is always a mechanical coupling between the electric machine and the gear 15 and thus with the output element 3, which is fixedly connected to the gear 15. A torque can therefore always be transmitted from the electric machine to the output element 3 when the electric machine is switched to motor mode. In addition, a torque can be transmitted in an overlaying manner from the internal combustion engine via the input element 2 to the output element 3 when the clutch device 8 is closed. If it is opened, the internal combustion engine is decoupled. This is necessary, for example, when the electric machine is switched to generator mode and the rotor is to be driven via the output element 3 in order to recuperate energy.

[0031] A spring means 22 is provided here in the form of a disc spring 23, which, viewed axially, is arranged between the gear 15 and the release bearing 20 or a bearing ring 24 of the release bearing 20. This disc spring 23 axially bridges a narrow air gap 25, which exists between the fingers 16 and the release bearing 20 or the bearing ring 24 in the non-actuated position. The disc spring 23 axially biases the release bearing 20 and thus the movable device part 19 as a whole into the non-actuated position, i.e., against the non-movable device part 18. This thus provides a defined preload, which also acts on the ramp mechanism (not described in detail here), which achieves the axial displacement of the movable device part 19 relative to the fixed device part 18.Likewise, any tolerances are compensated for, just as the disc spring 23 dampens the contact of the release bearing 20 against the slightly spaced fingers 16, thus preventing impact noise. The disc spring 23 can also be used to drain oil flowing outward during rotation, just as the disc spring 23 also assists in returning the release bearing 20 to the non-actuated position.

[0032] Figure 2 shows an enlarged partial view of the disc spring 23 arranged between the gear 15 and the release bearing 20 or its bearing ring 24, which, as a rotationally symmetrical structure, can be rotated about the axis of rotation D. This disc spring 23 is directly supported on both and rests with its inner circumference on the gear 15 and its outer circumference on the bearing ring 23.

[0033] An alternative arrangement is shown in Figure 3. There, the disc spring 23 is arranged with its outer circumference on the gear 15 and the inner circumference on the bearing ring 24 of the release bearing 20.

[0034] Figure 4 shows a representation of the disc spring 23, which has projecting fingers 26 on the inner circumference, which serve to engage in corresponding receptacles either on the gear 15 or on the release bearing 20. Figure 5 shows an assembly situation. There, the gear 15 has several receptacles 27 in the form of openings or recesses corresponding to the number of fingers 26, into which a finger 26 engages each. Naturally, the angular spacing of these receptacles 27 corresponds to the angular spacing of the fingers 26. The outer circumference of the disc spring 23 is in turn supported on the bearing ring 24.

[0035] In the arrangement variant shown in Figure 6, a disc spring 23 is used, with fingers 26 located on the outer circumference. Here, too, the outer fingers 26 engage in corresponding receptacles 27 on the gear 15 and are connected to the gear in a rotationally fixed manner via this engagement. Here, the inner circumference is again supported on the bearing ring 24.

[0036] The above statements apply equally if a disc spring package is used as the spring means instead of just one disc spring 23.

[0037] Figure 7 shows an alternative embodiment with a spring means 22 in the form of a helical spring 28, wherein several, for example three or four, such helical springs 28 are arranged around the circumference. In the illustrated embodiment, the or each helical spring 28 is received in a holder designed as a recess 29 on the gear 15 and is preferably pressed therein. The axially projecting end of the helical spring is axially supported on the axial bearing 20 or the bearing ring 24.

[0038] In the variant according to Figure 8, each coil spring 28 is in turn received or pressed into a corresponding holder on the gear 15, designed as a recess 29. The other end is arranged or pressed onto a holder provided on the bearing ring 24 in the form of a projecting pin 30, so that a bilateral attachment to both components is provided.

[0039] Although not shown, it is of course also conceivable that the coil springs 28 are attached only to holders in the form of projecting pins 30 on the bearing ring 24. While Figures 7 and 8 show cylindrical coil springs 28 as the spring means 22, the embodiment variant according to Figure 9 provides a spring means 22 in the form of a wave spring 31, which consists, for example, of several corrugated spring sections arranged one above the other. This fundamentally cylindrical wave spring can also be fixed either only in a holder on the gear 15, only in a holder on the bearing 24, or in holders on both components.

[0040] Figure 10 shows a configuration in which leaf springs 32 are used as spring means 22. These individual leaf springs are attached to the gear 15 via corresponding fastening means 33 in the form of rivets, again preferably distributed equidistantly around the circumference. They are supported axially on the bearing 24 of the axial bearing 20. This also allows for a corresponding preloaded support to be easily implemented.

[0041] Finally, Figure 11 shows an embodiment in which a spring ring 34 made of an elastic plastic material is provided as the spring means 22. This spring ring 34 is attached to the gear 15, for example, via an adhesive connection. The axial bearing 20 is in turn axially supported on it via the bearing 24, and the axial bearing 20 is in turn axially preloaded.

[0042] List of reference symbols

[0043] Coupling device Input element Output element Damper device Housing cover Screw connection Coil spring

[0044] Clutch device outer plate carrier outer plate

[0045] inner disc carrier inner disc disc spring

[0046] Abutment gear finger

[0047] Release device, device part, release bearing

[0048] External toothing spring means

[0049] Disc spring bearing ring air gap finger

[0050] Mounting coil spring recess

[0051] Pin wave spring 32 leaf spring

[0052] 33 fasteners

[0053] 34 spring ring

[0054] D axis of rotation

Claims

Patent claims 1. Coupling device for a hybrid drive device comprising an internal combustion engine and an electric machine for detachably connecting the internal combustion engine to an output element (3) coupled to the electric machine, comprising an input element (2) to be coupled to the internal combustion engine, a clutch device (8) coupled to the input element and actuated via an actuating element, to which the output element (3) is coupled, a gear (15) to be coupled to the electric machine, connected to the output element (3) and carrying a disk carrier (11) of the clutch device (8), and a release device (17) comprising a release bearing (20) axially movable from a non-actuated position into an actuated position, which is coupled to the clutch device (8) and is actuated upon an axial movement of the release bearing (20) into the actuated position,wherein the release bearing (20) is preloaded into the non-actuated position via a spring means (22).

2. Coupling device according to claim 1, characterized in that the spring means (22) is supported on the one hand on the release bearing (20) and on the other hand on the gear wheel (15) or on the actuating element.

3. Coupling device according to claim 1 or 2, characterized in that the spring means (22) is an annular spring element.

4. Coupling device according to claim 3, characterized in that the annular spring element is a disc spring (23) or a disc spring assembly or a spring ring (34) made of an elastic plastic material.

5. Coupling device according to claim 4, characterized in that the disc spring (23) or the disc spring assembly has one or more projecting fingers (26) on the inner circumference and / or on the outer circumference, via which it is suspended in or on receptacles on the release bearing (20) and / or the gear (15) or the actuating element.

6. Coupling device according to claim 1 or 2, characterized in that the spring means (22) comprises a plurality of individual spring elements which are arranged separately at different circumferential positions.

7. Coupling device according to claim 2 and 6, characterized in that holders to which the spring elements are fastened are provided on the release bearing (20) and / or on the gear (15) or the actuating element, or that the spring elements are fastened via separate fastening elements on the gear (15) or the actuating element or on the release bearing (20).

8. Coupling device according to claim 6 or 7, characterized in that the spring elements are coil springs (28) or wave springs (31) or leaf springs (32).

9. Coupling device according to claim 7 and 8, characterized in that the helical springs (28) or the corrugated springs (31) are pushed onto holders in the form of projecting pins (30) or pushed into holders in the form of recesses (29), or that the leaf springs (32) are fastened by means of fastening elements in the form of rivets (33).

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