WO2015000811A1

WO2015000811A1 - Coupling

Info

Publication number: WO2015000811A1
Application number: PCT/EP2014/063730
Authority: WO
Inventors: Herbert Steinwender
Original assignee: Magna Powertrain Ag & Co Kg
Priority date: 2013-07-04
Filing date: 2014-06-27
Publication date: 2015-01-08
Also published as: DE102013213144B4; DE102013213144A1

Abstract

The invention relates to a coupling for a motor vehicle, comprising a first and a second shaft (W1, W2) having a common axis, a coupling sleeve (KR), which is supported on the first shaft (W1) in a rotationally fixed and axially movable manner and which can be moved in the direction of the second shaft (W2) for the purpose of coupling, a ball ramp mechanism, which acts on the coupling sleeve (KR) and has an axially supported control ring (SR2), which is supported in such a way that the control ring can be rotated in relation to the second shaft (W2), and a brake disk (B2), which is supported on the second control ring (SR2) in a rotationally fixed and axially movable manner and which interacts with the pole of a housing-fixed electromagnet (EM) to generate a braking torque.

Description

clutch

The present invention relates to a clutch for interrupter unit of a motor vehicle of the type of claim 1.

For motor vehicles with shiftable four-wheel drive, the drive motor produces - eg. an internal combustion engine - one axle permanently driven. Accordingly, the engine is connected via a transmission with the drive axle. The connection of the wheels of the second axle via a breaker unit, a Disconnect unit, via a switchable coupling, by means of which and a shaft, the wheels of the second axis are driven. The coupling of a disconnect unit is designed as a positive coupling, through which the further drive axle is switched on or off. In addition, a synchronization may be provided, so that the positive coupling takes place only when the parts to be coupled have the same, approximately the same speed.

DE 10 2009 045 423 A1 describes a locking arrangement for a differential gear consisting of an electromagnet with an anchor element and a ball ramp mechanism. Switched is a frictional connection between the shaft and a differential case.

A actuated by a ball ramp coupling between two rotating elements shows the DE 69 705 195 T2. A planetary gear set with an annulus is electromagnetically coupled to the control ring. DE 69 70 058 T2 describes a gear shift system for a transmission with a main shaft and a countershaft. Provided is a ball ramp mechanism, consisting of an actuating ring and a control ring, which both surround the main shaft. A housing-fixed coil arrangement causes via a frictional coupling of the control ring with a main shaft gear, which results in a rotation of the control ring to the actuating ring.

DE 10 2009 005 378 A1 describes a drive train for a motor vehicle, consisting of a drive motor which drives the wheels of the front axle directly via a gearbox and a differential. Via a distribution unit with a multi-plate clutch, a PTO (Power Transfer Unit), the transmission of an adjustable torque via a ring gear and a shaft to the rear wheels, the rear axle, to a final gearbox with differential (final drive). The shaft can be switched via a form-fitting coupling, a disconnect unit, which precedes the final drive. can be switched on or off.

The solution of the above object is achieved by a coupling with the features of claim 1. Further developments emerge from the subclaims.

The coupling according to the invention consists of a first and a second shaft, which are positively coupled to each other by an axially displaceable coupling ring, wherein the axially displaceable coupling ring is pressed by spring force in the closing direction and operated against the spring force via a ball ramp mechanism opening. The first shaft is connected to the differential or gear wheel of the distribution unit, the PTO, the second shaft to the shaft of the final drive. The ball ramp mechanism consists of two control rings which can be rotated relative to one another and have balls mounted in corresponding structures, so that an axial displacement movement occurs when the rings are rotated. The twisting movement of the rings of the ball ramp Mechanism is effected by the rotational movement of the coupling system by applying a braking torque against the rings of the ball ramp mechanism, wherein the braking torque is applied by means of an electromagnet.

According to one embodiment of the invention, the axially displaceable and preferably designed as a sintered component coupling ring forms the one control ring of the ball ramp mechanism. The coupling ring is rotatably and axially displaceably mounted on the one shaft and cooperates with a corresponding structure of the second wave form fit. First and second wave are aligned on one axis.

By a compression spring, the coupling ring is pressed axially in the direction of the second shaft and coupled in this advanced position, the first and the second wave form fit.

The second control ring of the ball ramp mechanism comprises the second shaft, is rotatably mounted with respect to this and axially supported by a needle bearing on this. A rotation of the second control ring relative to the first control ring, the coupling ring causes disengage an axial displacement of the coupling ring against the spring force in the direction. First and second control ring or the coupling ring and the second control ring are stretched over the axially on the first shaft supporting spring against the second shaft or housing.

On the first control ring or the coupling ring and the second control ring in each case a brake disc is coupled, in rotation and axially movable. The brake discs are metallic or magnetizable and interact with a housing-mounted suspended and arranged between the discs electromagnets together. The brake discs interact with the two poles of the mag- Neten over an air gap as an anchor, are thus energized by the electromagnet when energized. Upon rotation of the coupling system - first and second shaft - can be braked by the electromagnet, the discs and so the coupling ring, the second control ring are subjected to a braking torque.

The brake disk of the second control ring forms the Aktuierungsbremsscheibe which exerts a braking torque on the second control ring. Due to the rotation of the shafts, the ball ramp is unscrewed via the braked second control ring. The advanced by the spring force in the coupled position coupling ring is disengaged, the clutch, the waves separated.

The first brake disc, the brake disc of the clutch ring acts as a retaining disc. When the electromagnet is energized, both brake disks are tightened - starting from the coupled state. The second brake disc unscrews the ball ramp apart, causing a disengagement of the coupling ring. The first shaft, which is connected to the gear wheel of the PTO, now comes to a standstill and is held by the attracted and coupled to the coupling ring disc. Both tightened brake discs now hold in position in the disengaged twisted ball ramp in position and prevent the clutch, the coupling ring again positively engages the second shaft. The holding current of the electromagnet for the two brakes can be greatly reduced in this case, since there are no air gaps in the magnetic circuit.

In the Connect case, to re-engage the first wave is first synchronized back to the input speed high. Both brake discs cause loss friction and the braking torque of the second brake disc, second control ring, holds the ball ramp in its open position. If both shafts are running synchronously, switching off the holding current in the electromagnet causes a release ben the brakes, the brake discs and thus the ball ramp is released, the main spring memory, the spring rotates the ball ramp back to its original position. The coupling ring, the sliding sleeve couples again. Should it come to a tooth tooth position, the spring acts as a spring memory and continues the axial movement of the coupling ring until it comes to a tooth to gap position and engagement.

Further, a further spring on the first brake disc, the brake disc of the coupling ring may be arranged, which presses the brake disc in a position away from the electromagnet. This spring is axially supported on the coupling ring and forms an armature spring.

Furthermore, the explanation of an embodiment of the invention with reference to the drawings.

Figure 1 shows an embodiment of the coupling according to the invention with a first shaft W1, connected to a not shown ring gear of a PTO's and a second shaft W2, connected to the final drive output. On the shaft W1, a coupling ring KR is rotatably and axially displaceably mounted in a multi-tooth profile, which is pressed by a spring F in a coupling position. The coupling ring KR acts as a sliding sleeve. The axially aligned with the shaft W1 shaft W2 has a cooperating with the coupling ring KR structure in the region of its front end. This coupling structure is designed, for example, as a continuation of the multi-tooth profile of the shaft W1 and causes the coupling ring KR to be pushed by the shaft W1 onto the shaft W2 - with the rear end still engaged in the shaft W1 - and thus coupling both shafts , In the position shown in Figure 1, the coupling ring KR is pressed by the force of the spring F in the coupling structure of the shaft W2 and the two shafts W1, W2 are positively coupled. The parts forming the ball ramp mechanism, the clutch ring KR and the second control ring SR2 are preferably made of sintered components.

On the shaft W2 sits rotatably and axially supported via a thrust bearing AL, a second control ring SR2, which forms a ball ramp mechanism, a Kugelrampenaktuator with the coupling ring KR as the first control ring SR1 and therebetween in gradient backdrops running balls. The current in pitch backdrops balls K are guided by a cage, not shown. The ball ramp mechanism acts against the spring F. In FIG. 1, the ball ramp mechanism is shown bolted together - the coupling ring KR is coupled to the shaft W2.

Rotationally and axially displaceable on the control ring SR1, i. the brake ring B1 and B2 are each mounted on the clutch ring KR and the control ring SR2. Between the two brake discs B1, B2, a solenoid EM is fixed to the housing, the two poles of which are respectively associated with the brake discs B1, B2 seated on the coupling ring KR and the control ring SR2. To close the magnetic circuit of the brake B2, the brake B1 is used. By the brake B1, the switched state is blocked and thus kept in the switched state.

FIG. 2 shows the embodiment according to FIG. 1 - here a spring FB1, an armature spring is additionally arranged on the coupling ring KR, by means of which the brake disk B1 is pushed away from the electromagnet EM. As a result, losses in the switching process still to be explained can be reduced. This armature spring causes, when switching, energizing the electromagnet EM immediately tightened the second brake disc B2, the control ring SR2 braked and screwing the ball ramp is effected.

FIG. 3 shows, starting from the situation as shown in FIG. and declutching process. The rotating shafts W1, W2 cause by the switched electromagnet EM and the braking torque on the brake disc B2 and the control ring SR2 screwing the ball ramp mechanism - the coupling ring KR is disengaged against the spring force F from the shaft W2. The connected to the differential, the ring gear of a PTO shaft W1 thereby reaches standstill, the tightened brake disc B1 thus prevents the coupling ring KR at a return to the ball ramp.

4 shows the switching process - starting from the coupling position of Figure 2 - in conjunction with the armature spring FB1. The switching, energizing the electromagnet EM initially causes a tightening and braking of the brake disc B2 and thus screwing the ball ramp - the disengagement of the coupling ring KR begins. The brake disk B1 clamped by the armature spring FB1 first comes into contact with the electromagnet EM when the coupling ring KR is completely disengaged and the shaft 1 has come to a standstill (FIG. 5).

FIG. 6 shows an embodiment in which the control ring SR2 is mounted in the form of an axial needle bearing via a thrust bearing AL supported on the housing. In the disconnected state, in the disconnect mode, the thrust bearing AL is also stationary, which prevents a corresponding drag torque.

FIG. 7 shows an embodiment in which the coupling ring KR is designed as an end-face claw coupling, the sliding sleeve of a front-end claw coupling. LIST OF REFERENCE NUMBERS

W1 first wave

W2 second wave

SR1 first control ring

KR coupling ring

SR2 second control ring

K ball

B1 brake disc

B2 brake disc

AL thrust bearing

EM electromagnet

F spring

FB1 spring, anchor spring

Claims

claims

1 . Coupling for a motor vehicle, comprising a first and a second shaft (W1, W2) with a common axis, a coupling sleeve (KR) mounted rotatably and axially displaceably on the first shaft (W1), which is for coupling in the direction of the second shaft (W2) is slidable, one on the coupling sleeve (KR) acting ball ramp mechanism, with a relative to the second shaft (W2) rotatably mounted axially supported control ring (SR2), a rotatably and axially displaceably mounted on the second control ring (SR2) mounted brake disc (B2), which cooperates to generate a braking torque with the pole of a housing-fixed electromagnet (EM).

2. Coupling according to claim 1,

the coupling sleeve (KR) is associated with a spring (F) acting in the direction of the second shaft (W2).

3. Coupling according to claim 1 or 2,

the coupling sleeve is formed as a coupling ring (KR) which simultaneously forms a control ring (SR1) of the ball ramp mechanism.

4. Coupling at least according to claim 3,

the ball ramp mechanism has at least one control ring (SR1, SR2) designed as a sintered shaped part.

5. Coupling according to one of the preceding claims,

the coupling sleeve, the coupling ring (KR) has rotationally fixed and axially displaceable on a brake disc (B1), which cooperates to generate a braking torque with a pole of a housing-fixed electromagnet (EM).

6. Coupling according to claim 5,

the electromagnet (EM) interacts with its two poles, each with a brake disc (B1, B2).

7. Coupling according to claim 5 or 6,

the brake disc (B1) is supported against the direction of the electromagnet (EM) by means of a spring (FB1) supported on the coupling sleeve, the coupling ring (KR).

8. Coupling at least according to claim 1,

the coupling sleeve is designed as a coupling ring (KR), which is articulated via a straight toothing on the first shaft (W1) and in a further spur toothing of the second shaft (W2) couples.

9. Coupling according to at least one of claims 1 - 7,

the coupling sleeve is designed as a coupling ring (KR), which is articulated via a straight toothing on the first shaft (W1) and positively cooperates with a coupling at the front end of the second shaft (W2).