WO2011079838A1

WO2011079838A1 - Crankshaft pulley

Info

Publication number: WO2011079838A1
Application number: PCT/DE2010/001503
Authority: WO
Inventors: Lászlo MAN
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2009-12-30
Filing date: 2010-12-20
Publication date: 2011-07-07
Also published as: DE112010005055A5; DE102010055272A1; DE112010005055B4

Abstract

The invention relates to a crankshaft pulley for transferring torque between a crankshaft and a pulley, comprising a freewheel. The invention is characterised in that the freewheel can be switched by means of a switching mass displaceable in a crankshaft pulley.

Description

Crankshaft pulley

The invention relates to a crankshaft pulley for transmitting a torque between a crankshaft and a belt drive, with a freewheel.

From the German patent application DE 195 35 889 A1 discloses a one-way clutch is known, which is arranged between a pulley and a shaft. The known overrunning clutch is suitable for driving a generator and is part of a pulley, which serves to drive the generator. By using the one-way clutch an internal damping is made possible, so that the torque transmission of the traction mechanism is improved. European Patent EP 0 980 479 B1 discloses a belt drive system having a generator clutch freewheel clutch comprising a torsion coil spring and a one-way clutch mechanism. As a result, the driving torques of the generator pulley can be transmitted to a hub yielding. In addition, the generator pulley can be uncoupled from the hub in one direction. From the German patent DE 196 36 628 C1 a freewheel with a clamping body is known, which is formed by a circumferentially extending gap, elastically deformed coil spring. European Patent EP 0 782 674 B1 discloses a crank-shaft decoupler with a directionally switched clutch which serves to selectively transmit rotational forces between a mounting hub and a pulley. German Offenlegungsschrift DE 10 2005 029 351 A1 discloses a drive wheel for driving an auxiliary unit of an internal combustion engine with a damping device.

The object of the invention is to provide a space-neutral solution for a decoupled from the crankshaft crankshaft pulley according to the preamble of claim 1. In this case, the crankshaft pulley according to the invention should in particular a start-stop operation, a stationary climate and generator operation, preferably with a pulse starting possibility including Kurbelwellentilger, and / or damping of rotational irregularities in the belt drive, allow.

The object is achieved in a crankshaft pulley for transmitting torque between a crankshaft and a belt drive, with a freewheel, characterized in that the freewheel by means of a movable in the crankshaft pulley shifting mass is switchable. To switch the freewheel, the mass moment of inertia of the shift mass is used. A switching operation is preferably triggered by the control of an electric machine, which is coupled via the belt drive with the crankshaft pulley. This has the advantage that no external switching device is needed.

A preferred embodiment of the crankshaft pulley is characterized in that the crankshaft pulley has an annular space for movably receiving the shift mass. The annular space is preferably completely surrounded by individual parts of the crankshaft pulley.

Another preferred embodiment of the crankshaft pulley is characterized in that the shift mass is firmly connected to a switching element for the freewheel. The switching element is preferably designed as a sheet metal part and is therefore also referred to as a reversing plate. The attachment of the switching mass to the switching element can be done for example by rivet connecting elements, which are integrally connected to the switching element.

Another preferred embodiment of the crankshaft pulley is characterized in that a freewheel cage of the freewheel is rotatably connected to the switching element. The freewheel cage is rotatable between two end positions in which the freewheel cage is held by a locking device, in particular by a locking spring.

A further preferred embodiment of the crankshaft pulley is characterized in that a central screw which is fixed to the crankshaft, a freewheel inner ring is, which can be coupled with the interposition of a bearing device and the freewheel with a freewheel outer ring. The freewheel is preferably designed as a roller freewheel with ramps. The bearing device is preferably designed as a ball bearing, in particular as a double ball bearing, with a cage.

A further preferred embodiment of the crankshaft pulley is characterized in that a pulley track is coupled via a slip clutch with the freewheel outer ring. About the slip clutch or a starting torque of an internal combustion engine can be safely transmitted, but overlying torque peaks are reduced. Another preferred embodiment of the crankshaft pulley is characterized in that the slip clutch comprises friction linings, which are biased by a plate spring against each other. The plate spring is supported in the axial direction, for example by means of an axial locking ring on the freewheel outer ring.

Another preferred embodiment of the crankshaft pulley is characterized in that the friction clutch comprises a pressure plate and a slide bearing support, between which a radially inwardly extending flange of the pulley track is clamped. The clamping of the Riemenscheibenspurflanschs is effected, preferably with the interposition of friction linings, by the plate spring.

Another preferred embodiment of the crankshaft pulley is characterized in that the slide bearing support supports a sliding bearing, through which the pulley track is rotatably mounted. The slide bearing support is, for example by rivet fasteners, firmly connected to the freewheel outer ring.

A further preferred embodiment of the crankshaft pulley is characterized in that the annular space for the movable recording of the shift mass of the freewheel outer ring, the slide bearing support and an absorber mass is limited. The absorber mass is, preferably with the interposition of a rubber track, mounted on a Tilgermassenträger rotatably connected to the crankshaft.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, an embodiment is described in detail.

In the single accompanying figure, a crankshaft pulley according to the invention is shown in longitudinal section through the crankshaft.

FIG. 1 shows a crankshaft pulley 1 according to the invention in various illustrations and individual parts. The crankshaft pulley 1 includes a pulley track 2, which is also referred to as a pulley or belt track for a short time, and serves to couple a belt of a belt drive to a belt starter generator and / or to an air conditioning compressor. The crankshaft pulley 1 is attached by means of a central screw 5 to a crankshaft 4 of a motor vehicle. The crankshaft 4 is driven by an internal combustion engine, which is also referred to as an internal combustion engine.

According to one essential aspect of the invention, a freewheel 8, a shifting mass 10 and a torsional vibration damping device 12 are integrated in the crankshaft pulley 1, which comprises a damping mass 14. Due to the freewheel e rotational irregularities of the crankshaft 4 can be reduced in the belt drive.

The central screw 5 comprises a screw head 16, from which a screw shaft 17 extends with a thread. The central screw 5 is screwed with the screw shaft 17 in a central threaded blind hole of the crankshaft 4.

According to one essential aspect of the invention, the freewheel 8 is connected by a targeted movement of the shift mass 10 by their own inertia. The targeted movement of the shift mass is generated by the control of an electric machine, for example, the starter generator in the drive train of the motor vehicle. An external switching device for switching the freewheel 8 can thus be omitted.

The shift mass 10 is arranged movably in an annular space 20 which is arranged completely within the crankshaft pulley 1 and is limited by individual parts of the crankshaft pulley 1. The switching mass 10 is fixedly connected to a switching element 24, which is designed as a sheet metal part. The switching element 24 has radially outside a flange 23 which extends radially outward. The flange 23 comprises distributed over its circumference a plurality of through holes, through which in each case a rivet connection element 21 extends therethrough, which is integrally connected to the shift mass 10. With the help of the rivet connection elements 21, the shift mass 10 is attached to the switching element 24 in a simple manner.

The switching element 24 is held radially on the outside by means of retaining clips 25 in the axial direction on a flange 26 which extends from a freewheel outer ring 28 radially outwardly. In this case, the switching element 24 is attached by means of the retaining clip 25 to the flange 26, that the switching element 24 can rotate together with the shift mass 10 relative to the freewheel outer ring 28. The central screw 5 is a freewheel inner ring of the freewheel 8. For this purpose 16 raceways for rolling elements of a bearing device 30 are formed on the central screw 5 radially outward on the screw head. In addition, a raceway for rollers of the freewheel 8 is mounted on the screw head 17 radially outward. The bearing device 30 is designed as a double ball bearing and serves to store the crankshaft pulley 1 on the crankshaft 4 and on the central screw 5. The freewheel 8 is arranged together with the bearing device 30 radially between the freewheel inner ring shown by the central screw 5 and the freewheel outer ring 28. The freewheel outer ring 28 is radially inwardly provided with raceways for the balls of the bearing device 30. In addition, radially inwardly of the freewheel outer ring 28, ramps of the freewheel 8 are formed, which preferably has two effective directions or blocking directions.

With the help of rivet connection elements 32, a support 34 for a sliding bearing 35 is attached to the flange 26 of the freewheel outer ring 28. The sliding bearing 35 serves to support the pulley track 2 rotatably relative to the freewheel outer ring 28.

From the pulley track 2, a flange 36 extends radially inwardly. The flange 36 of the pulley track 2 is clamped with the interposition of friction linings between a pressure plate 38 and the slide bearing support 34. Characterized a slip clutch 39 is provided, the clamping action is generated by a prestressed plate spring 40. The plate spring 40 is supported by means of an axial securing ring 41 in the axial direction on the freewheel outer ring 28. Radially outward, the plate spring 40 abuts on the pressure plate 38, which is non-rotatably connected by positive locking with the slide bearing support 34.

The absorber mass 14 of the torsional vibration damper 12 is attached by means of a rubber track 48 to a Tilgermassenträger 45. The Tilgermassenträger 45 is preferably designed as a sheet metal part and with the aid of a clamping piece or pressure piece 44 by the central screw 5 rotatably connected to the crankshaft 4. The absorber mass 14 extends in the radial direction between the switching element 24 and the belt track 2 in such a way that it delimits the annular space 20 in an axial direction. In the other axial direction of the annular space 20 is bounded by the flange 26 of the freewheel outer ring 28 and the slide bearing support 34. Radially inside the annular space 20 is limited by the switching element 24. Radially outside the annular space 20 is limited by the slide bearing support 34. For sealing, a radial shaft sealing ring 50 is arranged between the switching element 24 and the clamping piece or pressure piece 44. In the vicinity of the radial shaft sealing ring 50, the switching element 24 and a locking spring 55 is mounted in the freewheel outer ring 28. The locking spring 55 serves to lock the freewheel cage of the freewheel 8 in its two end positions. The locking spring 55, together with the freewheel cage of the freewheel 8 and the switching element 24 is a Rastiereinheit or Rastiervorrichtung. To seal a seal 60 is disposed between the freewheel outer ring 28 and the switching element 24, which is designed as an O-ring.

The switching mass 10 is firmly connected to the switching element 24 and has a relatively large inertia. The freewheel cage, which is responsible for the switching of the freewheel 8, is rotatably connected to the switching element 24 and can be rotated in two end positions on the freewheel outer ring 28, where it is held by the Rastiereinheit the locking spring 55. The freewheel outer ring 28 is connected to the belt track 2 via the slip clutch 39, which transmits the starting torque of the internal combustion engine safely, but degrades the overlying torque peaks.

In stand-air operation, the freewheel 8 is overhauled with the possible idle speed in the belt drive. The freewheel cage is in its front end position (generator operating effective direction). When the crankshaft pulley 1 is greatly accelerated by the electric machine via the belt drive for a starting operation, the shift mass 10 remains due to their inertia. The detent of the freewheel cage is overcome and the freewheel cage is rotated by the moment of inertia of the shift mass 10 in the rear end position, where it engages. In this case, the effective direction of the freewheel 8 is switched.

The reversed freewheel 8 engages suddenly (starter effective direction), the slip clutch 39 slips through and the crankshaft 4 is accelerated to the starting speed. After the starting process, the crankshaft pulley 1 is briefly greatly delayed, causing the shift mass 10 takes the freewheel cage in the front end position, where it engages again and the freewheel in this case switches (generator operational effective direction). The detent by means of the detent spring 55 must be strong enough to accommodate the spring force in the freewheel 8 and the mass forces through the normal crankshaft uniformities. The brief strong deceleration of the belt drive by the electric machine must be so great that the detent can be overcome. The switching direction of the freewheel 8 can also be reversed. LIST OF REFERENCES

Crankshaft pulley

belt track

crankshaft

central screw

freewheel

switching mass

Torsional vibration damping device

absorber mass

screw head

screw shaft

annulus

Nietverbindungselement

flange

switching

headband

flange

Freewheel outer ring

Storage facility

Nietverbindungselement

slide bearing support

bearings

flange

printing plate

slip clutch

Belleville spring

circlip

clamp

Tilgermassenträger

rubber track

Radial shaft seal

detent

poetry

Claims

claims

1. crankshaft pulley for transmitting a torque between a crankshaft (4) and a belt drive, with a freewheel (8), characterized in that the freewheel (8) by means of a in the crankshaft pulley (1) movable switching mass (10) is switchable.

2. crankshaft pulley according to claim 1, characterized in that the crankshaft pulley (1) has an annular space (20) for movably receiving the shift mass (10).

3. crankshaft pulley according to claim 2, characterized in that the shift mass (10) fixed to a switching element (24) for the freewheel (8) is connected.

4. crankshaft pulley according to claim 3, characterized in that a freewheel cage (8) rotatably connected to the switching element (24) is connected.

5. crankshaft pulley according to one of the preceding claims, characterized in that a central screw (5) which is fixed to the crankshaft (4), a freewheel inner ring, with the interposition of a bearing device (30) and the freewheel (8) with a freewheel outer ring (28) can be coupled.

6. crankshaft pulley according to claim 5, characterized in that a pulley track (2) via a slip clutch (39) with the freewheel outer ring (28) can be coupled.

7. crankshaft pulley according to claim 6, characterized in that the friction clutch (39) comprises friction linings, which are biased by a plate spring (40) against each other.

8. crankshaft pulley according to claim 6 or 7, characterized in that the slip clutch (39) comprises a pressure plate (38) and a slide bearing support (34), between which a radially inwardly extending flange (36) of the pulley track (2) is clamped ,

9. crankshaft pulley according to claim 8, characterized in that the slide bearing support (34) a sliding bearing (35) is supported, through which the pulley track (2) is rotatably mounted.

10. crankshaft pulley according to claim 9, characterized in that the annular space (20) for movably receiving the shift mass (10) of the freewheel outer ring (28), the slide bearing support (34) and a damping mass (14) is limited.