DE112014001024B4 - Pulley with a torque transmission device for selective torque transmission - Google Patents

Abstract

Belt pulley (RS) with a torque transmission device with a switching element for torque transmission of a torque in certain operating states, wherein in other operating states the torque cannot be transmitted or can be transmitted in a different direction, the switching element being actuable by means of a lifting magnet (D) mounted in a rotationally fixed manner in the torque transmission device, characterized in that a movement axis (19) of the lifting magnet (D) coincides with a longitudinal axis of a central screw (S) with which the belt pulley (RS) can be mounted on a crankshaft (KW).

Description

The invention relates to a pulley with a torque transmission device for transmitting torque of a relatively high torque in certain operating states, although in other operating states the torque should not be transmitted or should be transmitted in a different direction. The invention relates to the use of the pulley in drive trains, transmissions, engines, belt and chain drives, etc. In particular, the invention can be used in pulleys with a switchable element with play, such as a claw clutch or pawl freewheel.

Crankshaft pulleys with decoupling elements made of rubber or steel and crankshaft torsion dampers with rubber, steel or viscosity spring elements are already known. Switchable planetary gears with a wide variety of switching elements such as roller freewheels, pawl freewheels, claw clutches, etc. are also known in combination with crankshaft torsion dampers with rubber, steel or viscosity spring elements but without vibration decoupling of the switching element. Switchable pulleys such as magnetic clutches, hydraulic, pneumatic or lever or cable operated clutches have already been shown.

The DE 10 2010 060 594 A1 discloses a clutch with a clutch system that is connected between a drive element designed as a pulley and an output element. Elastic actuators are located within the clutch system and are connected to a switching element. The switching element is moved from an off position to a switching position in which the clutch system is closed when an actuation system is activated by the auxiliary energy of an elastic actuator. The actuator stores the energy when the switching element is switched off.

From the DE 10 2011 104 135 A1 a pulley damper for damping torsional vibrations of a drive shaft is known, which has a pulley for driving a traction means, in particular a traction belt, and a hub which can be connected in a rotationally fixed manner to the drive shaft. Furthermore, a torsional vibration damper, in particular a decoupler for torsional vibrations, is provided for transmitting a torque introduced via a hub flange connected to the hub to the pulley. The hub has a radial sliding surface that rests radially on the pulley and an axial sliding surface that rests axially on the pulley. Through the sliding surfaces of the hub, both an axial plain bearing and a radial plain bearing for supporting the pulley on the hub can be formed without separate bearings, so that the structure of the pulley is simplified and the pulley can be manufactured more cost-effectively.

Although the known pulleys with decoupling elements reduce the vibrations introduced by the crankshaft, they have not yet been designed to be switchable. Switchable planetary gears usually have no decoupling and therefore experience high torques and accelerations. The switchable pulleys known to date require high actuation energies.

The object of the present invention is to compensate for the disadvantages mentioned. In particular, a belt pulley is to be created with a torque transmission device with low actuation force and high transferable torque, which also has the vibration advantages of vibration decoupling. This decoupling reduces both the loads on the switching element and the downstream belt drive.

The task is solved with the features of patent claim 1. The subclaims show advantageous embodiments of a pulley with a torque transmission device.

The pulley with a torque transmission device with a switching element for torque transmission of a torque in certain operating states, wherein in other operating states the torque cannot be transmitted or can be transmitted in a different direction, the switching element being actuable by means of a lifting magnet mounted in a rotationally fixed manner in the torque transmission device, is characterized in that that an axis of movement of the lifting magnet coincides with a longitudinal axis of a central screw with which the pulley can be mounted on a crankshaft. The lifting magnet is advantageously arranged radially within components of the pulley. The central arrangement of the lifting magnet can advantageously save installation space. The lifting magnet is also advantageously arranged to overlap components of the pulley in the axial direction. The lifting magnet advantageously has a substantially circular cylindrical housing. For example, an electromagnetic coil is arranged in the housing of the lifting magnet, which interacts with an armature that can be moved back and forth along the axis of movement of the lifting magnet. The housing of the lifting magnet with the electromagnetic coil is mounted so that it cannot rotate. The armature of the solenoid is relative to the housing with the electromagnetic coil fixed to the housing can be moved back and forth along the axis of movement of the lifting magnet. The armature of the lifting magnet is advantageously combined with an actuating plunger, which projects from the housing of the lifting magnet into the interior of the pulley and is used to actuate the switching element.

The switching element can be a claw clutch or a freewheel, which are actuated directly by means of a lifting magnet mounted in a rotationally fixed manner in the torque transmission device.

When using the torque transmission device in a pulley for driving auxiliary units in a motor vehicle, a crankshaft torsion damper can be vulcanized directly to the flange element of an arc spring decoupler.

All bearing elements can be lubricated either with oil or grease.

The decoupling and switching unit can either be delivered open or oil-tight for assembly on the motor vehicle.

Optionally, a pre-assembly of the crankshaft torsion damper on the crankshaft and a subsequent assembly of the pre-assembled decoupling and switching unit including lifting magnet or a pre-assembly of the crankshaft torsion damper, decoupling and switching unit on the crankshaft and a subsequent assembly of the lifting magnet can take place.

A further preferred embodiment of the pulley is characterized in that the lifting magnet comprises an actuating element which can be moved back and forth and which can be moved towards the central screw, in particular into a recess in the central screw. The actuating element is also referred to as an actuating plunger and is used to actuate the switching element. The recess in the central screw is designed, for example, as a hexagon socket and is used when assembling the pulley for a rotation-proof connection with a tool, in particular an Allen key. After the belt pulley has been mounted on the crankshaft, the recess in the central screw can advantageously serve to accommodate one end of the actuating element, in particular the actuating plunger. As a result, the required installation space can advantageously be further reduced. The actuating element, in particular the actuating plunger, protrudes with its free end into the recess of the central screw only in an extended state. When the actuating element, in particular the actuating plunger, is in a retracted state, the free end normally does not protrude into the recess in the central screw.

A further preferred embodiment of the pulley is characterized in that the lifting magnet represents a final assembly unit which, after assembly of the pre-assembled pulley, in particular after filling the pulley with lubricant, is mounted in such a way that the lifting magnet closes the pulley in a lubricant-tight manner. The pre-assembled pulley advantageously includes all components of the pulley, apart from the lifting magnet including a connecting cable and, if necessary, a torque arm for the lifting magnet. The inventive design of the pulley and the arrangement of the lifting magnet make it possible to mount the pre-assembled pulley on the crankshaft in a particularly simple manner. The installation space for the lifting magnet simplifies the positioning of a tool, in particular the insertion of the central screw with the tool through the pre-assembled pulley. During final assembly, the lifting magnet is easily inserted into the pre-assembled pulley and is attached in a rotationally fixed manner with the help of the torque support, in particular a correspondingly rigid connection cable, for example supported on a stationary crankcase.

A further preferred embodiment of the pulley is characterized in that the crankshaft torsion damper represents a first pre-assembly unit and the arc spring decoupler with the lifting magnet represents a second pre-assembly unit. The first pre-assembly unit is advantageously attached to the crankshaft using the central screw. The second pre-assembly unit is then advantageously screwed onto the first pre-assembly unit attached to the crankshaft using suitable fastening means, such as fastening screws.

The invention may also relate to a method for assembling a previously described pulley. The design of the pulley according to the invention, in particular due to the special arrangement of the lifting magnet, considerably simplifies the assembly of the pulley in large-scale industrial series production.

• 1 das prinzipielle Funktionsschema einer erfindungsgemäßen Drehmomentübertragungsvorrichtung und ein Ausführungsbeispiel einer erfindungsgemäßen Riemenscheibe;
• 2 einen Ausschnitt der Riemenscheibe aus 1 mit einer geschlossenen und einer geöffneten Kupplung;
• 3 ein weiteres Ausführungsbeispiel einer erfindungsgemäßen Riemenscheibe mit einem schaltbaren Freilauf;
• 4 vergleichend zwei Ausführungsbeispiele I und II, die unterschiedlich montiert werden können;
• 5 vergleichend zwei Ausführungsbeispiele I und III, die unterschiedlich geschmiert werden und
• 6 vergleichend zwei Ausführungsbeispiele II und IV, die unterschiedlich geschaltet werden.

Further advantages, features and details of the invention emerge from the following description, in which various exemplary embodiments are described in detail with reference to the drawing. Show it:

• 1 the basic functional diagram of a torque transmission according to the invention supply device and an embodiment of a pulley according to the invention;
• 2 a section of the pulley 1 with one closed and one open clutch;
• 3 a further embodiment of a pulley according to the invention with a switchable freewheel;
• 4 comparing two embodiments I and II, which can be mounted differently;
• 5 comparing two embodiments I and III, which are lubricated differently and
• 6 comparing two exemplary embodiments II and IV, which are switched differently.

1 shows the basic functional diagram in its right part and an exemplary embodiment of the invention in its left part. The pulley unit is attached to the crankshaft KW of an internal combustion engine by means of a central screw S. The supporting element is a damper flange 3, which establishes the connection to the crankshaft KW and, together with a flywheel ring 1 and a rubber spring 2, forms the crankshaft torsion damper A. At the same time, the damper flange 3 is the input part of the crankshaft decoupler B, which consists of the counter disk 4, the bow springs 5 and the damper flange 6. The damper flange 6 is supported via the bearing 7, which is centered in the damper flange 3 via the bearing dome 3a.

The pulley RS is mounted in the counter pulley 4 by means of a bearing 12 and can be freely rotated relative to it. If torque is to be transferred to the belt drive, the dog clutch C must be closed. This consists of the toothed input part 8 connected to the damper flange 6, a toothed sliding sleeve 9 preloaded by a spring 10 and a toothed output part 11 connected to the pulley RS.

The claw clutch is opened by actuating an armature of a lifting magnet D acting against the spring 10. This is arranged in a rotationally fixed manner to the crankcase by means of a torque arm 13. The solenoid is also supplied with power via the torque arm. It is mounted in the pulley by means of the bearing 14, the force on the sliding sleeve is transmitted via the bearing 16 and the pressure piece 17.

2 shows a section of the embodiment 1 , with the closed claw clutch shown in the left half of the drawing and the open claw clutch shown in the right half of the drawing.

The lifting magnet D comprises a magnetic actuator 15 with a substantially cylindrical housing, which is arranged in a rotationally fixed manner to the crankcase via the torque arm 13. An electromagnetic coil is arranged in the housing of the lifting magnet D, which interacts with a magnet armature which can be moved back and forth along a movement axis 19.

The axis of movement 19 coincides with a longitudinal axis of the central screw S and the axis of rotation of the crankshaft KB. The magnet armature of the lifting magnet D is combined with an actuating element designed as an actuating plunger 20, which protrudes from the housing of the lifting magnet D. The actuating plunger 20 is coupled via the bearing 16 to the pressure piece 17, with which the sliding sleeve 9 of the claw clutch C is actuated.

In 2 On the left, the actuating plunger 20 is shown in a retracted position. In the retracted position of the actuating plunger 20, the clutch is closed. In 2 On the right, the actuating plunger 20 is shown in its extended position, in which a free end of the actuating plunger 20 projects into a recess 21 in the central screw S. The recess 21 is designed, for example, as a hexagon socket and is used during assembly to hold a tool, in particular an external hexagon wrench. In the extended position of the actuating plunger 20, the clutch is opened.

The actuating force for extending the actuating plunger 20 is caused by energizing the electromagnetic coil of the magnetic actuator 15. If the current supply to the electromagnetic coil of the magnetic actuator 15 is interrupted, then the biasing force of the spring 10 ensures that the actuating plunger 20 is released from its in 2 extended position shown on the right back into its in 2 retracted position shown on the left is moved back.

In 3 A further embodiment of the invention is shown, in which the dog clutch is represented by a switchable freewheel 30. For example, a switchable pawl freewheel can be used, as shown in the functional diagram under the pulley unit shown in different switching positions. Such a pawl freewheel can be switched in such a way that torque transmission in opposite directions of relative rotation is possible. In principle, there are two freewheels acting in opposite directions through a common switch device can be switched. The switching device is actuated by means of the solenoid, with the axial movement being converted into a rotary movement for the switching device. In the exemplary embodiment shown, generator operation is possible in one position and boost operation in the other switching position.

However, other circuits are also possible, for example a freewheel in one position and a fixed connection for both directions of rotation in the other position. Of course, an appropriately designed switchable roller freewheel can also be used. Corresponding freewheels and switching elements are in the patent application DE 10 2013 221 835 A1 shown.

The freewheel 30 includes a freewheel outer ring 31 and a freewheel inner ring 32. The freewheel outer ring 31 is firmly connected to a belt track of the pulley RS via rivet connecting elements. The freewheel inner ring 32 is firmly connected to the damper flange 6.

Depending on the switching position of the switchable freewheel 30, a relative rotation between the freewheel outer ring 31 and the freewheel inner ring 32 is enabled or blocked. For this purpose, for example, pawls 33 are used, which can be actuated against the biasing force of a spring device 34 with the aid of a switching element 35.

The switching element 35 of the freewheel 30 is coupled via a bearing 36 to an actuating plunger 37, which protrudes from the housing of the lifting magnet D. In 3 On the left, the actuating plunger 37 is shown in a retracted position. In the retracted position of the actuating plunger 37, generator operation of the pulley RS is enabled. In 3 On the right, the actuating plunger 37 is shown in an extended position. In the extended position of the actuating plunger 37, a boost state of the pulley RS is made possible.

In 3 The function of the pawl freewheel is illustrated below in a rectangle 39. The pawl freewheel includes a switching element 40, via which a first pawl 41 and a second pawl 42 can be actuated. In the rectangle 39 above, the first pawl 41 is deactivated by the switching element 40. The second pawl 42 is activated. Generator operation is enabled via the activated second pawl 42. In the rectangle 39 below, the first pawl 41 is activated by the switching element 40. The second pawl 42 is deactivated. Boat operation is made possible via the activated first latch 41.

In 4 Two embodiments of a pulley according to the invention are shown in comparison. In version I, the pulley unit is mounted via the central screw S on the crankshaft, oil is then filled in and the system is closed oil-tight by mounting the lifting magnet designed as a magnetic actuator 15. In version II, the crankshaft torsion damper A is mounted on the crankshaft via the central screw S, then the pulley unit, which has already been filled with oil and pre-assembled with the magnetic actuator 15, is attached to the crankshaft torsion damper A using the screws 18.

5 compares two embodiments, with version I being the version I 4 corresponds. In version I, the decoupler, bearings and coupling are lubricated using oil; the oil chamber is closed after assembly using the sealing elements. In version III, the decoupler and the bearings are lubricated separately using grease; the coupling is not lubricated.

6 shows a comparison of two embodiments. Version II (corresponds to version II 4 ) has a claw clutch, version IV has a switchable pawl freewheel.

The invention relates to a torque transmission device for torque transmission of a relatively high torque in certain operating states, although in other operating states the torque should not be transmitted or should be transmitted in a different direction. In particular, the invention relates to a belt pulley with a crankshaft torsion damper, belt drive decoupling and switching element with special detailed solutions and embodiments. Switchable pulleys have considerable potential in the intelligent coupling of combustion engines and electric motors (hybrid drive). As a result of the invention presented, both functional and cost advantages can be expected compared to the prior art.

Reference symbol list

1

Swing ring

2

Rubber spring

3

damper flange

3a

Warehouse Dome

4

counter disk

5

bow spring

6

damper flange

7

camp

8th

Entrance part

9

Sliding sleeve

10

Feather

11

Output part

12

camp

13

Torque arm

14

camp

15

Magnetic actuator

16

camp

17

Pressure piece

18

screws

19

axis of movement

20

Actuating plunger

21

recess

30

Freewheel

31

Freewheel outer ring

32

Freewheel inner ring

33

Latches

34

Spring device

35

Switching element

36

camp

37

Actuating plunger

39

rectangle

40

Switching element

41

first handle

42

second handle

A

Crankshaft torsion damper

b

Crankshaft decoupler

C

Claw coupling

D

Lifting magnet

KW

crankshaft

RS

pulley

S

Central screw

Claims (8)

Belt pulley (RS) with a torque transmission device with a switching element for torque transmission of a torque in certain operating states, wherein in other operating states the torque cannot be transmitted or can be transmitted in a different direction, the switching element being actuable by means of a lifting magnet (D) mounted in a rotationally fixed manner in the torque transmission device, characterized in that a movement axis (19) of the lifting magnet (D) coincides with a longitudinal axis of a central screw (S), with which the belt pulley (RS) can be mounted on a crankshaft (KW). Pulley (RS). Claim 1 , characterized in that the switching element is a dog clutch (C) or a freewheel (30). Pulley according to one of the preceding claims, characterized in that the pulley (RS) is used to drive auxiliary units in a motor vehicle and has a crankshaft torsion damper (A) and an arc spring decoupler (B). pulley Claim 3 , characterized in that a rubber track (2) of the crankshaft torsion damper (A) is vulcanized directly on an input flange element (3) of the arc spring decoupler (B). Pulley according to one of the preceding claims, characterized in that bearing elements of the pulley (RS) are lubricated with oil or grease. Pulley according to one of the preceding claims, characterized in that the lifting magnet (D) comprises an actuating element (20) which can be moved back and forth and which moves towards the central screw (S), in particular into a recess (21) in the central screw (S). is movable. Pulley according to one of the preceding claims, characterized in that the lifting magnet (D) represents a final assembly unit which is mounted after assembly of the pre-assembled pulley (RS), in particular after filling lubricant medium into the pulley (RS), in such a way that the Lifting magnet (D) closes the pulley (RS) so that it is lubricant-tight. Pulley according to one of the Claims 3 until 7 , characterized in that the crankshaft torsion damper (A) represents a first pre-assembly unit and the arc spring decoupler (B) with the lifting magnet (D) represents a second pre-assembly unit.

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