DE102019119490B4 - Axle drive with a differential and a separating clutch - Google Patents

Abstract

Axle drive (1) with a differential (7), a differential housing (18), a separating clutch (8) integrated into the differential housing (18), a release bearing (19) for actuating the separating clutch (8), an actuator (22) and power amplification means (21), wherein the release bearing (19), for actuating the separating clutch (8), can be axially displaced via the force amplification means (21) by means of the actuator (22), characterized in that the force amplification means (21) have a release lever (23) and have a toggle lever (24), the release lever (23) being rotatably mounted in the region of one end in an axle gear housing (20) and contacting the release bearing (19) at a distance from this end, the toggle lever (24) having two lever sections rotatably connected to one another (27, 28), one lever section (27) being rotatably mounted in the axle gear housing (20) and the other lever section (28) being rotatably mounted in the release lever (23), in whose axis of rotation (25) of the release lever (2 3) in the end remote from the axle gear housing (20), the axes of rotation (26, 29, 30) of the toggle lever (24) being arranged parallel to one another, the actuator (22) supporting the lever section (27) mounted in the axle gear housing (20) at a distance from its axis of rotation (29) in the axle drive housing (20), the lever sections (27, 28) enclosing a larger angle with one another when the separating clutch (8) is actuated than when the separating clutch (8) is not actuated.

Description

The invention relates to an axle drive with a differential, a differential housing, a separating clutch integrated into the differential housing, a release bearing for actuating the separating clutch, an actuator and power amplification means, the release bearing for actuating the separating clutch being axially displaceable via the power amplification means by means of the actuator.

Separating clutches in axle drives are used, for example in hybrid vehicles, to couple or uncouple electric drive machines from the drive train as required. Due to the power density, these are usually represented as claw couplings. Actuation takes place via an electric lifting magnet, an electric servomotor or a hydraulic system, depending on the requirements.

If a defined function, in particular automatic opening, is required in a claw clutch in the event of a malfunction, such as a machine short circuit, then a deflecting flank angle is necessary, which requires high holding forces during operation. This leads to correspondingly large, complex actuator systems, such as in hydraulic solutions with pumps, valves and cylinders. Actuator systems with electric servomotors are not self-opening due to the large drive ratio when de-energized.

An axle drive that has the features of the type mentioned and the features of the preamble of claim 1 is from the DE 36 08 118 A1 known. In this axle drive, the force amplification means are essentially formed by an expanding ring and a plurality of rocker arms with which the expanding ring interacts. The respective rocker arm is supported on the release bearing about halfway along its length. One end of the rocker arm is mounted in the expansion ring and the other end of the rocker arm is axially and radially fixed with respect to a hub. When the actuator is actuated, specifically an axial displacement of a sleeve, the expansion ring spreads and pivots the respective rocker arm with respect to its central contact area on the release bearing. Such a design of the axle drive is complex in terms of the design and arrangement of the force amplification means, since a large number of individual components have to be provided and these are moreover connected in a complicated manner to the actuator, the release bearing and the hub. - This document discloses a non-positive locking clutch, which is designed as a multi-plate clutch, of a locking differential gear of a motor vehicle. The lock-up clutch can be actuated by an electromagnet.

In the DE 10 2013 003 810 A1 describes a valve closing device with a locking device for locking an emergency drive. The locking device is coupled to a lifting magnet via a toggle lever, whereby a high holding force can be generated.

From the DE 10 2009 029 005 A1 an electromechanical operating arrangement for at least one shift element of a vehicle transmission with at least one drive device is known. This drive device drives a spindle drive of an actuating device for actuating the switching element. The adjusting device comprises a toggle lever mechanism actuated via the spindle drive.

In the DE 10 2012 218 472 A1 describes a device and a method for quickly opening a clutch. Here, a mechanical transmission path between a clutch actuator and a first clutch part has a toggle lever.

From the DE 103 16 949 A1 a parking lock for a motor vehicle is known. To operate the parking lock, a toggle lever mechanism is used which has at least two legs and a common knee joint.

From the DE 103 03 984 A1 an axle drive with a differential lock is known.

The object of the present invention is to develop an axle drive of the type mentioned at the outset in such a way that, with a simple design of the means for actuating the separating clutch, only low holding forces are necessary when the separating clutch is activated.

The object is achieved by an axle drive which is designed according to the features of claim 1.

In the case of the axle drive, the force amplification means have a release lever and a toggle lever. Here, the release lever is rotatably mounted in an axle drive housing in the region of one end and contacts the release bearing at a distance from this end, approximately halfway along the release lever. The toggle lever has two lever sections rotatably connected to one another, one lever section being rotatably mounted in the axle gear housing and the other lever portion being rotatably mounted in the release lever in whose end facing away from the axis of rotation of the release lever in the axle gearbox housing. The axes of rotation of the toggle lever are arranged parallel to one another. The actuator makes contact with the lever section mounted in the axle gear housing at a distance from its axis of rotation in the axle gear housing. The lever sections close when the disconnect clutch is actuated a larger angle with each other than when the disconnect clutch is not actuated.

In order to reduce the holding forces in the switched end position, the release lever is operated indirectly by the actuator via a toggle mechanism. In this switching position, this is advantageously supported in an almost straight alignment against a bearing in the axle drive housing. Only small actuation forces are therefore required on the actuator. From this point of view, the actuator is preferably electrically operative. It is designed, for example, as an electric lifting magnet. The actuator has, for example, an electric ring magnet or an electric servomotor.

Preferably, not only are the axes of rotation of the lever sections arranged parallel to one another, but also these axes of rotation and the axis of rotation of the release lever are arranged parallel to one another. This simplifies the structural design of the axle drive and the arrangement of toggle lever and release lever in the axle drive.

An electrical holding magnet is preferably mounted in the axle drive housing, the toggle lever contacting the holding magnet in the area of its central joint connecting the lever parts in the relatively extended toggle lever position, corresponding to its position when the separating clutch is actuated. This electric holding magnet supports the holding forces of the actuator, for example the lifting magnet, in the extended toggle lever position.

A plate spring is advantageously arranged between the differential housing and the release bearing, the plate spring exerting a contact pressure on the release bearing. The disc spring thus ensures an uninterrupted contact pressure on the release bearing.

The separating clutch is, in particular, a claw clutch. This claw coupling has in particular repelling flank angles. This design of the claw coupling ensures that in the event of a malfunction, for example a machine short circuit, in particular automatic opening of the claw coupling is guaranteed, regardless of the requirement that a deflecting flank angle is necessary, which requires high holding forces during operation. The actuation of the claw clutch via the force amplification means described with a high final translation requires only small holding forces that have to be applied by the actuator, with which a very simple actuator can be used.

A shift ring of the dog clutch advantageously has pressure segments which extend through openings in the differential housing.

The invention and its developments thus propose, in particular, a toggle lever mechanism arranged between a release lever and an axle gear housing. The toggle lever is connected in an articulated manner to the movable end of the release lever and is articulated in the axle drive housing. When the claw clutch is closed, the toggle lever is only a few degrees, approx. 5 °, in front of its extended position. The release lever is rotatably mounted in the axle drive housing. The dog clutch is arranged within the differential housing. The claw clutch is actuated via the release lever and the release bearing. The switching ring of the dog clutch has pressure segments that extend through openings in the differential housing. The angular end position of the toggle lever is determined by a stop in the axle drive housing. An electrical holding magnet fixed to the housing in the area of the central joint of the toggle lever supports the holding forces of the actuator, in particular the lifting magnet, in the largely extended toggle lever position. A disc spring between the differential housing and the release bearing is used to ensure an uninterrupted contact pressure on the release bearing.

Further features of the invention emerge from the subclaims, the attached drawing and the description of the exemplary embodiments reproduced in the drawing, without being restricted thereto.

• 1 ein Elektrofahrzeug, das mit erfindungsgemäßen Achsgetrieben bei achsparalleler Anordnung ausgebildet ist,
• 2 die achsparallele Anordnung gemäß 1 in vergrößerter Darstellung,
• 3 in einer Darstellung entsprechend 2 eine koaxiale Anordnung,
• 4 für die koaxiale Anordnung eine Detaildarstellung in einem Schnitt veranschaulicht,
• 5 ein abgewandeltes Ausführungsbeispiel in einer Darstellung gemäß 4.

It shows:

• 1 an electric vehicle that is designed with axle drives according to the invention with an axially parallel arrangement,
• 2 the axially parallel arrangement according to 1 in an enlarged view,
• 3 in a representation accordingly 2 a coaxial arrangement,
• 4th for the coaxial arrangement illustrates a detailed representation in a section,
• 5 a modified embodiment in a representation according to 4th .

1 shows an electric vehicle 1 with front axle 2 and rear axle 3 . The forward direction of travel of the electric vehicle 1 is by the arrow 4th made clear.

The front axle 2 or the rear axle 3 an identical drive is assigned to each, which is an electric motor 5 , an axle drive 6th with differential 7th and a disconnect clutch 8th having. Across from the differential 7th outgoing drive shafts 9 , 10 are wheels 11 the respective axle - front axle 2 or rear axle 3 - drivable.

• Eine Ausgangswelle 12 des Elektromotors 5 ist drehfest mit einem Ritzel 13 verbunden, das mit einem Zahnrad 14 einer Zwischenwelle 15 kämmt. Drehfest mit dieser Zwischenwelle 15 ist ein weiteres Zahnrad 16 verbunden, das einen kleineren Durchmesser aufweist als das Zahnrad 14. Dieses Zahnrad 16 kämmt mit einem Finaldrive-Zahnrad 17. Dieses Zahnrad 17 ist mit einem Differenzialgehäuse 18 drehfest verbunden. In das Differenzialgehäuse 18 ist die Trennkupplung 8, bei der es sich um eine Klauenkupplung mit abweisenden Flankenwinkeln handelt, integriert. Die Trennkupplung 8 wird über ein als Wälzlager ausgebildetes Ausrücklager 19 betätigt. Dieses ist in einem Achsgetriebegehäuse 20 angeordnet, das die erörterten Komponenten 12 bis 17, das Differenzialgehäuse 18 sowie die innerhalb des Differenzialgehäuses 18 angeordneten Komponenten - Differenzial 7 und Trennkupplung 8 - aufnimmt. Im Achsgetriebegehäuse 20 sind ferner Kraftverstärkungsmittel 21 angeordnet, die mittels eines am Achsgetriebegehäuse 20 angeflanschten Aktuators 22 betätigbar sind. Bei dem Aktuator 22 handelt es sich beispielsweise um einen Hubmagneten. Die Kraftverstärkungsmittel 21 weisen einen Ausrückhebel 23 und einen Kniehebel 24 auf. Das Ausrücklager 19 zum Betätigen der Trennkupplung 8 ist bei Beaufschlagung des Aktuators 22 betätigbar.

2 shows the respective area of the electric vehicle 1 who have favourited the electric motor 5 and the final drive concern, in more details:

• An output shaft 12th of the electric motor 5 is non-rotatable with a pinion 13th connected that with a gear 14th an intermediate shaft 15th combs. Rotationally fixed with this intermediate shaft 15th is another gear 16 connected, which has a smaller diameter than the gear 14th . This gear 16 meshes with a Finaldrive gear 17th . This gear 17th is with a differential case 18th non-rotatably connected. In the differential housing 18th is the disconnect clutch 8th , which is a claw coupling with repelling flank angles. The disconnect clutch 8th is via a release bearing designed as a roller bearing 19th actuated. This is in an axle drive housing 20th arranged that the discussed components 12th to 17th , the differential case 18th as well as those inside the differential housing 18th arranged components - differential 7th and disconnect clutch 8th - records. In the axle drive housing 20th are also power amplification agents 21 arranged by means of an on the axle drive housing 20th flanged actuator 22nd are operable. With the actuator 22nd it is, for example, a lifting magnet. The power amplification means 21 have a release lever 23 and a knee lever 24 on. The release bearing 19th to operate the disconnect clutch 8th is when the actuator is applied 22nd operable.

The release lever 23 is in the area of one end around an axis 25th in the axle drive housing 20th rotatably mounted and contacted at a distance from this end, about half the length of the release lever 23 , the release bearing 19th . The knee lever 24 has two around an axis 26th rotatably interconnected lever sections 27 , 28 on. Here is the lever section 27 around an axis 29 in the axle drive housing 20th rotatably mounted and it is the other lever section 28 around an axis 30th rotatable in the release lever 23 stored, in the area of the axis 25th of the release lever 23 remote end. The axes 25th , 26th , 29 and 30th are arranged parallel to each other. The actuator 22nd contacts the lever portion 27 at a distance from its axis 29 . In detail, the lever section 26th in the area of the axis 29 an approach 31 on which an actuator 32 of the actuator 22nd contacted. When the actuator moves out 32 this pivots the lever section 27 such that the toggle lever 24 is transferred from a less stretched position to a more stretched position. The lever sections 27 , 28 close when the disconnect clutch is actuated 8th a larger angle with each other than when the disconnect clutch is not actuated 8th . The state of the actuated disconnect clutch is shown 8th . Here take the two lever sections 27 , 28 an almost extended position, with a deviation from a lever extended position by a few degrees, in particular approx. 5 °.

The lever section 27 is due to the area of attack for the actuator 22nd L-shaped. The lever sections 27 , 28 have the same lever length, based on the distance between the axes 26th and 29 or. 26th and 30th , on. The lever length of the release lever 23 is based on the distance between the axes 25th and 30th , 2 to 4th Times as large, preferably 2.5 to 3.5 times as large, in particular 3 times as large as the lever length of the knee lever 24 , based on the distance between the averted axes 29 , 30th with activated disconnect clutch 8th . Through this training of the power transmission means 21 high holding forces can be achieved on the release bearing 9 with small actuation forces on the actuator 22nd produce.

The lever sections 27 , 28 when the separating clutch is actuated, they enclose an angle of 172 ° to 178 °, preferably 174 ° to 176 °, in particular 175 °, with one another. The latter angle corresponds to 5 ° before the lever extended position.

3 shows a basic arrangement according to 2 , but with a coaxial axle drive. With the embodiment according to 2 Components that match in terms of structure and function are denoted by the same reference numerals. In this respect, in order to avoid repetition, reference is made to the remarks on 2 referenced. In this coaxial axle drive, the output shaft is 12th of the electric motor 5 designed as a hollow shaft, the drive shaft 9 penetrates the hollow shaft. The output shaft 12th is non-rotatable with a sun gear 33 a planetary gear 34 connected. Over in a planet carrier 35 planet gears with bearings 36 is the sun gear 33 to a ring gear 37 of the planetary gear 34 tied up. The ring gear 37 is in the axle drive housing 20th stored and rotatably connected to this.

• In dieser Figur sind wiederum die entsprechenden zum Ausführungsbeispiel nach 3 beschriebenen Bauteile mit denselben Bezugsziffern bezeichnet.

The arrangement according to 3 is, with regard to the presently relevant components, in 4th illustrated in detail:

• In this figure are again the corresponding to the embodiment according to 3 components described with the same reference numerals.

4th shows the force amplifying means with solid lines 21 with activated disconnect clutch 8th , so when the claw clutch is closed, a few degrees of angle (approx. 5 °) before the extended lever position. Here is the actuator 32 of the actuator 22nd or lifting magnets extended. The situation when the disconnect clutch is not actuated is shown with dotted lines 8th , thus shown with the claw clutch open. Here are the lever sections 27 , 28 of the knee lever 24 significantly more kinked.

Regarding the differential 7th is also a differential planet carrier 38 illustrated.

The lever section 27 is in the area of the axis 26th on its the final drive housing 20th facing side with a ledge 39 provided that when the disconnect clutch is actuated 8th , thus in the position of the knee lever 24 a few degrees before the lever extended position, a stop 40 of the axle drive housing 20th contacted. This is the stretching movement of the toggle lever 24 limited.

Between the differential case 18th and the release bearing 19th is a spring designed as a disc spring 41 to compensate for component tolerances and to ensure an uninterrupted contact pressure on the release bearing 19th arranged. There is also a switching ring 42 the separating clutch designed as a claw clutch 8th provided with pressure segments that extend through openings in the differential housing 18th extend.

The embodiment according to 5 differs from the one after the 4th by the fact that instead of a stop 14th one in the final drive housing 20th bearing magnet 43 is provided. This housing-mounted electrical holding magnet 43 supports in the area of the central joint, thus the axis 26th of the knee lever 24 the holding forces of the actuator 22nd , in this case the solenoid, in the extended toggle lever position.

List of reference symbols

1

Electric vehicle

2

Front axle

3

Rear axle

4th

arrow

5

Electric motor

6th

Axle drive

7th

differential

8th

Disconnect clutch

9

drive shaft

10

drive shaft

11

wheel

12th

Output shaft

13th

pinion

14th

gear

15th

Intermediate shaft

16

gear

17th

gear

18th

Differential housing

19th

Release bearing

20th

Axle gear housing

21

Strength reinforcement agents

22nd

Actuator

23

Release lever

24

Knee lever

25th

axis

26th

axis

27

Lever section

28

Lever section

29

axis

30th

axis

31

approach

32

Actuator

33

Sun gear

34

Planetary gear

35

Planet carrier

36

Planetary gear

37

Ring gear

38

Differential planet carrier

39

head Start

40

attack

41

feather

42

Switching ring

43

Holding magnet

Claims (15)

Axle drive (1) with a differential (7), a differential housing (18), a separating clutch (8) integrated into the differential housing (18), a release bearing (19) for actuating the separating clutch (8), an actuator (22) and power amplification means (21), wherein the release bearing (19), for actuating the separating clutch (8), can be axially displaced via the force amplification means (21) by means of the actuator (22), characterized in that the force amplification means (21) have a release lever (23) and have a toggle lever (24), the release lever (23) being rotatably mounted in the region of one end in an axle drive housing (20) and contacting the release bearing (19) at a distance from this end, the toggle lever (24) having two lever sections rotatably connected to one another (27, 28), wherein the one lever section (27) rotatably mounted in the axle gear housing (20) and the other lever section (28) rotatably in the release lever (23), in which the axis of rotation (25) of the Release lever (23) in the axle gear housing (20) at the end facing away, the axes of rotation (26, 29, 30) of the toggle lever (24) being arranged parallel to one another, the actuator (22) supporting the lever section (20) mounted in the axle gear housing (20). 27) at a distance from its axis of rotation (29) in the axle drive housing (20), the lever sections (27, 28) enclosing a larger angle with one another when the separating clutch (8) is actuated than when the separating clutch (8) is not actuated. Axle drive after Claim 1 , characterized in that the axes of rotation (26, 29, 30) of the lever sections (27, 28) and the axis of rotation (25) of the release lever (23) are arranged parallel to one another. Axle drive after Claim 1 or 2 , characterized in that the lever sections (27, 28) have the same lever length, based on the distances between the axes of rotation (26, 29; 26, 30) of the respective lever section (27, 28). Axle drive according to one of the Claims 1 to 3 , characterized in that the lever length of the release lever (23), based on the distance between the axes of rotation (25, 30) of the release lever (23) is 2 to 4 times as large, preferably 2.5 to 3.5 times as large, in particular 3 Is times as large as the lever length of the toggle lever (24), based on the distance between the opposite axes of rotation (29, 30) of the toggle lever (24) when the separating clutch is actuated. Axle drive according to one of the Claims 1 to 4th , characterized in that the lever sections (27, 28), when the separating clutch (8) is actuated, enclose an angle of 172 ° to 178 °, preferably 174 ° to 176 °, in particular 175 °, with one another. Axle drive according to one of the Claims 1 to 5 , characterized in that the axle gear housing (20) has a stop (40) for fixing the toggle lever (24) in an angular end position when the separating clutch (8) is actuated. Axle drive according to one of the Claims 1 to 6th , characterized in that the actuator (22) is an electrically acting actuator. Axle drive after Claim 7 , characterized in that the actuator (22) has an electric ring magnet or an electric servomotor. Axle drive according to one of the Claims 1 to 8th , characterized in that the lever section (27) rotatably mounted in the axle drive housing (20) is L-shaped, this lever section (27) being rotatably mounted in the area of two legs forming the L in the axle drive housing (20) and the actuator ( 22) contacts one leg in the region of its free end, and the other leg is rotatably connected to the other lever part (28). Axle drive according to one of the Claims 1 to 9 , characterized in that an electric holding magnet (43) is mounted in the axle drive housing (20), the toggle lever (24) in the area of the joint (26) connecting the lever sections (27, 28) corresponding to the actuated separating clutch (8) Knee lever position that makes contact with the holding magnet (43). Axle drive according to one of the Claims 1 to 10 , characterized in that a spring (41) is arranged between the differential housing (18) and the release bearing (19), the spring (41) causing a pressing force on the release bearing (19). Axle drive after Claim 11 , characterized in that the spring (41) is designed as a plate spring. Axle drive according to one of the Claims 1 to 12th , characterized in that the separating clutch (8) is designed as a claw clutch. Axle drive after Claim 13 , characterized in that the separating clutch (8) designed as a claw clutch has deflecting flank angles. Axle drive after Claim 13 or 14th , characterized in that a switching ring (42) of the separating clutch (8) designed as a claw clutch has pressure segments which extend through openings in the differential housing (18).

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