DE102019215275A1 - Clutch assembly and transfer case assembly comprising such a clutch assembly - Google Patents

Abstract

Clutch arrangement (1) for a motor vehicle drive train comprising an electric machine (2), an output component (3), a clutch (4) and an axial adjustment device (5), the electric machine (2) acting as a drive via the clutch (4) in a normal operating state is connected to the output component (3) and wherein the axial adjustment device (5) is arranged on the output component (3) and acts on the clutch (4) in such a way that the electrical machine (2) is in an exceptional operating state as a function of a speed gradient and / or a speed of the output component (3) via the clutch (4) is separated from the output component (3) and a transfer case arrangement with such a clutch arrangement (1).

Description

Field of invention

The present invention relates to a clutch arrangement for a motor vehicle drive train comprising an electric machine, an output component, a clutch and an axial adjustment device, the electric machine being connected to the output component via the clutch in a driving manner in a normal operating state, as well as a transfer case arrangement with such a clutch arrangement.

State of the art

In modern motor vehicle technology, the use of electrical machines in the motor vehicle drive train is hard to imagine. There are innumerable possible arrangements and uses of an electric machine - to name a few examples: as a drive unit in a hybrid or electric vehicle, in an electric motor vehicle axle, in a transfer case to provide an electric supporting torque, etc.

As a rule, the electric machine is at least indirectly connected to a motor vehicle axle so as to drive it, for example via a gear arrangement, which necessitates the electric machine in exceptional operating situations of a motor vehicle, i.e. in the event of rapid or unexpected braking or acceleration maneuvers, to protect against excessively high speeds and / or speed gradients or excessively high torques.

All-wheel-drive vehicles, for example, which represent an electrical supporting torque in the area of a transfer case by means of an electrical machine in order to distribute the mechanical torque of the main drive unit, usually an internal combustion engine, between a front axle and a rear axle of the motor vehicle in a fully variable manner regardless of wheel speeds, struggle with the above mentioned problem. Here, the front axle, the rear axle and the electric machine are usually coupled with effective drive via a planetary gear of the transfer case - speed differences between the two axles are passed on in the planetary gear and force the electric machine to speed. In exceptional operating situations of the motor vehicle, such as an ESP intervention or another “missuse” maneuver, very high speed gradients occur at wheel level. These propagate via the planetary gear in the direction of the electrical machine and, due to the inertia of the electrical machine, can cause unwanted coupling torques between the front axle and the rear axle. On the one hand, these disturbing torques can be disadvantageous in terms of driving dynamics and, on the other hand, lead to an overload of the planetary gear and the electrical machine.

Electric and hybrid motor vehicles with high-voltage systems and an electric machine as a drive unit often have a so-called two-speed design in order to be able to operate the electric machine in optimal operating ranges. In such a two-speed version, when upshifting from first gear to second gear, a shifting process without interruption of tractive effort should be ensured. A clutch is required in order to achieve a constant acceleration of the motor vehicle and at the same time carry out the speed jump of the electrical machine without jerks. However, this clutch should only go into engagement position during the speed jump.

In the prior art, actively actuated, i.e. Clutches operated by an actuator motor with control are used. This results in increased installation space and costs.

Summary of the invention

It is an object of the invention to specify a clutch arrangement with an electrical machine that ensures safe and / or optimized operation of the electrical machine with a construction that is optimized in terms of installation space, components and costs. Another object of the invention is to specify an improved transfer case arrangement.

This need can be met by the subject matter of the present invention according to independent claims 1 and 7. Advantageous embodiments of the present invention are described in the dependent claims.

A clutch arrangement according to the invention comprises an electrical machine, an output component, a clutch and an axial adjustment device.

According to the present invention, in a normal operating state of a motor vehicle, the electric machine is connected to the output component via the clutch in a driving manner.

Furthermore, according to the invention, the axial adjustment device is arranged on the output component and acts on the clutch in such a way that the electrical machine in an exceptional operating state of a motor vehicle depending on a speed gradient and / or a Speed of the output component is separated from the output component via the coupling.

In the following, a distinction is repeatedly made between a normal operating state and an exceptional operating state of a motor vehicle. In this context, an exceptional operating state of the motor vehicle is to be understood as an operating state of the motor vehicle in which the axle of the motor vehicle is sharply decelerated or accelerated abruptly. The normal operating state includes all other operating states of the motor vehicle.

The clutch becomes passive, i.e. without an actuator motor, depending on a speed gradient and / or a speed of the output component via the axial adjustment device in the disengaged position. In this way, the clutch arrangement can be represented in an optimized manner in terms of installation space, components and also costs.

The coupling can be designed as a frictional, positive or non-positive coupling.

The axial adjustment device is preferably designed in the form of a ball ramp arrangement. The ball ramp arrangement preferably has a first ramp disk rotatably disposed on the output component and a second ramp disk rotatably but axially displaceable on the output component. The first ramp disc and the second ramp disc preferably each have at least three identically designed depressions on their facing end faces, which are opposite each other in pairs and thus form at least three recess pairs, with a ball being arranged in each recess pair.

In a preferred embodiment variant, the depressions are each designed to rise symmetrically in a first circumferential direction and in a second circumferential direction of the respective ramp disk, starting from a bottom dead center.

Furthermore, the depressions preferably each have an incline in a radial direction starting from the bottom dead center. As an alternative to this, the depressions each have a radial gradient over their entire extent in the first circumferential direction as well as the second circumferential direction.

The transfer case arrangement according to the invention comprises a planetary gear, at least one clutch arrangement according to the invention and two output elements, with at least one output element representing the output component of the clutch arrangement, the two output elements being coupled in a drive-effective manner via the planetary gear and the electrical machine in a control operating state via the coupling of the clutch arrangement with the planetary gear Is drivingly connected and is separated in an exceptional operating state depending on a speed gradient and / or a speed of the output component via the clutch of the clutch assembly from the planetary gear.

Figure list

• 1 zeigt schematische Darstellung einer beispielhaften Kupplungsanordnung.
• 2a zeigt schematisch eine Rampenscheibe mit Vertiefungen gemäß einer ersten Ausführungsvariante.
• 2b zeigt eine Schnittansicht entlang einer Ebene A-A gemäß 2a.
• 3a zeigt schematisch eine Rampenscheibe mit Vertiefungen gemäß einer zweiten Ausführungsvariante.
• 3b zeigt eine Schnittansicht entlang einer Ebene B-B gemäß 3a
• 3c zeigt eine Schnittansicht entlang einer Ebene C-C gemäß 3a.
• 4a zeigt schematisch eine Rampenscheibe mit Vertiefungen gemäß einer dritten Ausführungsvariante.
• 4b zeigt eine Schnittansicht entlang einer Ebene D-D gemäß 4a
• 4c zeigt eine Schnittansicht entlang einer Ebene E-E gemäß 4a.
• 5 zeigt schematische Darstellung einer beispielhaften Kupplungsanordnung gemäß 1 mit einer aktiven Vorsteuerung.

The invention is described below by way of example with reference to the drawings.

• 1 shows a schematic representation of an exemplary clutch arrangement.
• 2a shows schematically a ramp disk with depressions according to a first embodiment variant.
• 2 B shows a sectional view along a plane AA according to FIG 2a .
• 3a shows schematically a ramp disk with depressions according to a second embodiment variant.
• 3b shows a sectional view along a plane BB according to FIG 3a
• 3c FIG. 13 shows a sectional view along a plane CC according to FIG 3a .
• 4a shows schematically a ramp disk with depressions according to a third embodiment variant.
• 4b shows a sectional view along a plane DD according to FIG 4a
• 4c shows a sectional view along a plane EE according to FIG 4a .
• 5 shows a schematic representation of an exemplary clutch arrangement according to FIG 1 with an active feedforward control.

Detailed description of the invention

In 1 is a clutch assembly 1 according to the present invention, which reacts passively to speed gradients and optionally to speed.

The clutch assembly 1 is installed in a drive train of a motor vehicle.

In the following, a distinction is repeatedly made between a normal operating state and an exceptional operating state of a motor vehicle. In this context, an exceptional operating state of the motor vehicle is to be understood as an operating state of the motor vehicle in which the axle of the motor vehicle is sharply decelerated or accelerated abruptly. The normal operating state includes all other operating states of the motor vehicle.

The clutch assembly 1 has an electrical machine 2 , a starting component 3 , a clutch 4th as well as an axial adjustment device 5 on.

The starting component 3 is as a wave 3 ' executed, which is connected to an axle of the motor vehicle.

The direction indication "axial" describes a direction along or parallel to a central axis of rotation 21st the wave 3 ' .

The direction indication “radial” describes a direction normal to the central axis of rotation 21st the wave 3 ' .

The axial adjustment device 5 is in the form of a ball ramp arrangement 5 ' educated. The ball ramp assembly 5 ' has one on the starting component 3 rotatably arranged first ramp disc 6th and one on the source component 3 non-rotatably but axially displaceably arranged second ramp disc 7th on. Preferably the first ramp washer 6th and the second ramp disc 7th at least three identically designed depressions on their facing end faces 8th which are opposite one another in pairs and thus form at least three pairs of wells, with one ball in each pair of wells 9 is arranged. The second ramp disc 7th has an essentially L-shaped cross-section with an axially extending area and a radially extending area ( 1 ). The depressions 8th are on the radially extending area of the second ramp disc 7th educated.

The coupling 4th is as a friction clutch, namely as a multi-plate clutch 4 ' executed. The multi-disc clutch 4 ' is designed as a "normally closed" clutch, ie the multi-disc clutch 4 ' is closed when not actuated. The multi-disc clutch 4 ' is in the normal operating state by the spring force of a main spring 11 kept locked closed. The spring force of an auxiliary spring 12 acts the spring force of the main spring 11 counteracts and provides the axial preload force as well as zero backlash and automatic reset between the first ramp disc 6th and the second ramp disc 7th for sure.

The electric machine 2 is about a gear 13 effective drive with a primary side of the multi-plate clutch 4 ' , namely an input element 14th with an external toothing 15th that rotates on the shaft 3 ' is arranged, connected. A secondary side of the multi-plate clutch 4 ' is solid with the shaft 3 ' connected. The electric machine 2 is in the normal operating state of the motor vehicle via the multi-plate clutch 4 ' effective drive with the shaft 3 ' connected.

On the axially extending area of the second ramp disc 7th a plurality of inner disks is arranged, which with a plurality of outer disks in an alternating arrangement form a disk pack 16 the multi-disc clutch 4 ' form, wherein a first part of the outer disks on the input element 14th that about its external gearing 15th with the gear 13 combs, is applied and a second part of the outer discs on the shaft 3 ' is applied.

Due to a driving maneuver, such as an ESP intervention, the wave becomes 3 ' extremely delayed. However, this delay and the associated speed gradient are not directly affected by the gearwheel 13 electrical machine connected effectively to drive 2 rather, the elasticities between the shaft are first applied 3 ' and the electric machine 2 curious; excited. This tensioning enables the speed gradient on the multi-plate clutch 4 ' arrives and thus also on the second ramp disc 7th works. The second ramp disc 7th gets from the wave 3 ' driven and makes the speed gradient with. The first ramp disc 6th however, it is only about the balls 9 driven and acts with its inertia against the movement of the second ramp 7th - this has a relative rotation of the first ramp disc 6th to the second ramp disc 7th result. This rotation causes the second ramp disk to shift axially 7th against the spring force of the main spring 11 the multi-disc clutch 4 ' . With increasing displacement of the second ramp disc 7th the force increases with the ball ramp assembly 5 ' of the multi-plate clutch 4 ' closing spring force of the main spring 11 counteracts. The multi-disc clutch 4 ' is thus from the locked, closed state, namely an engagement position, in an area in which the multi-plate clutch 4 ' Build up differential speed, or can open completely, so a release position, transferred. This function can be achieved by tuning the geometry of the indentations 8th in the two ramp washers 6th , 7th , the inertia of the first ramp disc 6th and by the design of the main spring 11 and the auxiliary spring 12 can be adjusted very well.

The multi-disc clutch 4 ' becomes passive, ie without an actuator motor, depending on a speed gradient and / or a speed of the shaft 3 ' via the ball ramp assembly 5 ' actuated in disengagement.

In 2a to 4c are different designs of the recesses 8th shown.

In the in 2a and 2 B The variant shown are the depressions 8th each starting from a bottom dead center 10 in a first circumferential direction I and in a second circumferential direction II of the respective ramp disc 6th , 7th symmetrically rising. A ramp disc 6th , 7th with depressions formed in this way 8th can react to speed gradients in both directions of rotation, namely to a braking torque and a drive torque on the part of the motor vehicle axle.

The second circumferential direction II is a circumferential direction opposite to the first circumferential direction I.

In the in 3a to 3c The variant shown are the depressions 8th each starting from the bottom dead center 10 in a first circumferential direction I and in a second circumferential direction II of the respective ramp disc 6th , 7th symmetrically rising and also point starting from the bottom dead center 10 a slope in a radial direction. A ramp disc 6th , 7th with depressions formed in this way 8th can react to a speed gradient in both directions of rotation and a speed. A defined dependency of speed and speed gradient is stored in the geometry of the ball ramp.

In the in 4a to 4c The depressions shown here are the alternative embodiment variants 8th each starting from the bottom dead center 10 in a first circumferential direction I and in a second circumferential direction II of the respective ramp disc 6th , 7th designed to rise symmetrically and each have a radial gradient over their entire extent in the first circumferential direction I as well as the second circumferential direction II. A ramp disc 6th , 7th with depressions formed in this way 8th can react to a speed and a speed gradient in both directions of rotation. The full stroke triggered by a speed gradient is still possible even under the influence of the speed.

In 5 is a clutch assembly 1 according to the in 1 The embodiment variant already shown is shown, which reacts passively to speed gradients and optionally to speed and can also be actively controlled. The active control takes place via a lifting magnet 17th executed actuator. One on the anchor rod 18th of the lifting magnet 17th attached friction cone 19th engages one on the first ramp disc 6th arranged mating cone 20th brought. Will the solenoid 17th Designed as a force-controlled proportional magnet, this can be done via the friction cone 19th applied braking torque and thus the opening characteristics of the multi-plate clutch 4 ' can be regulated as required. By means of the lifting magnet 17th can thus in a simple manner a pilot control of the ball ramp arrangement 5 ' and thus the multi-plate clutch 4 ' will be realized. The advantage is that the clutch assembly 1 is closed in itself and by the lifting magnet 17th Drag losses only occur during an exceptional operating state of the motor vehicle. The clutch arrangement is in the normal operating state 1 free from drag losses. In comparison, fully active clutch arrangements have, in some cases, significant drag losses due to supporting and actuating forces.

List of reference symbols

1

Clutch assembly

2

Electric machine

3

Starting component

3 '

wave

4th

coupling

4 '

Multi-disc clutch

5

Axial adjustment device

5 '

Ball ramp assembly

6th

First ramp disc

7th

Second ramp disc

8th

deepening

9

Bullet

10

Bottom dead center

11

Main spring

12

Auxiliary spring

13

gear

14th

Input element

15th

External toothing

16

Disk pack

17th

Lifting magnet

18th

Anchor rod

19th

Friction cone

20th

Counter cone

21st

Central axis of rotation (of the shaft)

Claims (7)

A clutch arrangement (1) for a motor vehicle drive train comprising - an electric machine (2), - a starting component (3), - a coupling (4) as well - An axial adjustment device (5), wherein the electrical machine (2) in a normal operating state via the coupling (4) is drivingly connected to the output component (3) and wherein the axial adjustment device (5) is arranged on the output component (3) and on the clutch (4) has the effect that the electrical machine (2) is separated from the output component (3) via the clutch (4) in an exceptional operating state depending on a speed gradient and / or a speed of the output component (3). Coupling arrangement (1) according to Claim 1 , characterized in that the clutch (4) is designed as a frictional, positive or non-positive clutch. Coupling arrangement (1) according to Claim 1 or 2 , characterized in that the axial adjustment device (5) is designed as a ball ramp arrangement (5 '), which includes a first ramp disc (6) rotatably arranged on the output component (3) and a second ramp disc (6) rotatably but axially displaceable on the output component (3). 7), the first ramp disc (6) and the second ramp disc (7) each having at least three identically formed depressions (8) on their facing end faces, which are opposite each other in pairs and thus form at least three depression pairings, with the depression pairings a ball (9) is arranged in each case. Coupling arrangement (1) according to Claim 3 , characterized in that the depressions (8) are designed to rise symmetrically in a first circumferential direction (I) as well as in a second circumferential direction (II) of the respective ramp disc (6, 7) starting from a bottom dead center (10). Coupling arrangement (1) according to Claim 4 , characterized in that the depressions (8) each have an incline in a radial direction starting from the bottom dead center (10). Coupling arrangement (1) according to Claim 3 , characterized in that the depressions (8) each have a radial gradient over their entire extension in the first circumferential direction (I) as well as the second circumferential direction (II). Transfer case arrangement for a motor vehicle drive train comprising a planetary gear, at least one clutch arrangement (1) according to one of the Claims 1 to 7th as well as two output elements, with at least one output element representing the output component (3) of the clutch arrangement (1), the two output elements being coupled in a driving manner via the planetary gear and the electric machine (2) of the clutch arrangement (1) in a regular operating state via the clutch (4 ) the clutch arrangement (1) is connected to the planetary gear with an effective drive and in an exceptional operating state depending on a speed gradient and / or a speed of the output component (3) of the clutch arrangement (1) via the clutch (4) of the clutch arrangement (1) separated from the planetary gear is.

Images