DE102011080771A1 - Crankshaft pulley - Google Patents

Abstract

The invention relates to a crankshaft belt pulley for transmitting torque between a crankshaft and a belt drive, with a planetary gear and at least one starter freewheel. The invention is characterized in that the starter freewheel is arranged between a ring gear of the planetary gear and a motor housing part.

Description

The invention relates to a crankshaft pulley for transmitting a torque between a crankshaft and a belt drive, with a planetary gear and at least one starter freewheel.

From the European patent EP 0 782 674 B1 is a Kurbelwellenentkuppler with a directional clutch known. From the European patent EP 0 980 479 B1 For example, a belt drive system with a generator link freewheel clutch is known.

The object of the invention is to further optimize a crankshaft pulley according to the preamble of claim 1, in particular with regard to different operating functions and / or the required installation space.

The object is achieved in a crankshaft pulley for transmitting torque between a crankshaft and a belt drive, with a planetary gear and at least one starter freewheel, characterized in that the starter freewheel between a ring gear of the planetary gear and a motor housing part is arranged. The motor housing part is a fixed housing part of a motor housing, for example a crankcase. Fixed means that the housing part performs no movement relative to the crankshaft pulley. The inventive arrangement of the starter freewheel resulting space advantages. In addition, in a simple manner, a switching of the starter freewheel by means of an electric motor allows, which may be attached to the motor housing part.

A preferred embodiment of the crankshaft pulley is characterized in that the starter freewheel has two stable torque transmitting positions in opposite directions of rotation. In one direction of rotation locks the starter freewheel to allow starting of the internal combustion engine. The starting of the internal combustion engine takes place, for example, with the aid of an electric motor, which is drivingly connected to the crankshaft via the belt drive and the crankshaft pulley. In the other direction of rotation locks the starter freewheel to allow high-lift via the planetary gear. The planetary gear is preferably designed with a gear ratio of about three to one. The stable positions of the starter freewheel are preferably made possible by detents. This means that the starter freewheel engages in the various positions and is selectively switched by the electric motor.

Another preferred embodiment of the crankshaft pulley is characterized in that the starter freewheel has a stable neutral position to allow a generator operation and / or operation of an accessory. In generator mode, for example, an accumulator or a battery is charged by a generator which is drivingly connected to the crankshaft via the crankshaft pulley and the belt drive. The auxiliary unit is, for example, an air conditioning system which is drivingly connectable to the crankshaft via the belt drive and the crankshaft pulley. In particular, a stationary climate operation is made possible in which a motor vehicle with the crankshaft pulley according to the invention is or an internal combustion engine of the motor vehicle is switched off. With the aid of the crankshaft pulley according to the invention, the auxiliary unit, in particular the air conditioning system, can be driven via the crankshaft pulley according to the invention and the belt drive by one or the electric motor, which is preferably designed as a starter generator. In the neutral position, clamping elements of the starter freewheel are levered out with the aid of a cage by an actuator so far that no torque is transmitted.

Another preferred embodiment of the crankshaft pulley is characterized in that the starter freewheel is switchable by an electric motor which is fixed to the motor housing part. In the electric motor, a reduction gear is preferably integrated to reduce the rotational speed of the electric motor for switching the starter freewheel. The electric motor has, for example, an adjusting gear with an outer toothing, which meshes with an outer toothing of an adjusting cage of the starter freewheel.

A further preferred embodiment of the crankshaft pulley is characterized in that the starter freewheel is switchable via an adjustment cage by the electric motor. The adjustment cage serves to accommodate or guide freewheel rollers or pinch rollers of the starter freewheel. The freewheel rollers are preferably provided with a two-sided Rollenanfederung.

Another preferred embodiment of the crankshaft pulley is characterized in that a booster freewheel between a sun gear of the planetary gear and the crankshaft is arranged. Boosting or boosting means that a starter generator, the internal combustion engine, which is also referred to as an internal combustion engine, via the belt drive and the crankshaft pulley according to the invention in translation one to one, that is, bypassing the Planetary gearbox, can drive. This makes it possible in a simple manner, for example, a traction help by the starter generator.

A further preferred embodiment of the crankshaft pulley is characterized in that the booster freewheel has two stable torque transmission positions in opposite directions of rotation. The booster freewheel locks in one direction of rotation to enable generator operation. In the other direction of rotation locks the boost freewheel to allow boosting the internal combustion engine with a one-to-one ratio. In this case, it is ensured, for example by means of springs, that the boost freewheel stably assumes its two torque transmission positions. With the help of the springs of the boost freewheel is preferably biased in its torque transmission position for the generator operation. The boost freewheel may optionally have an additional neutral position in which no torque is transmitted.

Another preferred embodiment of the crankshaft pulley is characterized in that the booster freewheel is switchable by a further electric motor which is fixed to the motor housing part. In the electric motor, a reduction gear is preferably integrated to reduce the rotational speed of the electric motor for switching the boost freewheel. The electric motor has, for example, an adjusting gear with an outer toothing, which meshes with an outer toothing of an adjusting ring of the boost freewheel.

A further preferred embodiment of the crankshaft pulley is characterized in that the booster freewheel is switchable via an adjusting ring by the further electric motor. The adjusting ring preferably interacts with a ramp element.

A further preferred embodiment of the crankshaft pulley is characterized in that the adjusting ring has radially outside a toothed portion with an external toothing and / or radially inside a spiral groove. The toothed portion serves to couple the adjusting ring with a Verstellzahnrad the electric motor. In the spiral groove engages, for example, at least one guide tab, which is preferably mounted radially on the outside of the ramp element.

The crankshaft pulley is preferably mounted on a crankshaft central bolt, by means of which the crankshaft pulley is attached to the crankshaft. The sun gear of the planetary gear is preferably combined with a freewheel outer ring of the boost freewheel. The combination of the two freewheels in the crankshaft pulley according to the invention can be realized in a simple manner different modes of a belt-driven starter generator, such as start / stop, stationary air conditioning and generator operation. In addition, allow the two electric motors in certain operating states, a decoupling of the planetary gear.

The invention further relates to a drive train of a motor vehicle, as described, for example, in German Offenlegungsschrift DE 10 2007 021 233 A1 is disclosed. The power transmission unit described therein is replaced by the crankshaft pulley according to the invention.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, various embodiments are described in detail. Show it:

1 a perspective sectional view of a crankshaft pulley according to the invention;

2 an enlarged upper half section of the crankshaft pulley 1 ;

3 an enlarged lower half section of the crankshaft pulley 1 ;

4 a perspective view of a Schaltaktorik for two freewheels of the crankshaft pulley from the 1 to 3 ;

5 a perspective view of a planet carrier with a second ramp plate of the crankshaft pulley from the 1 to 4 ;

6 a perspective view of the planet carrier of the crankshaft pulley 5 from a different angle;

7 a perspective view of a freewheel outer ring of the crankshaft pulley with a Verstellkäfig;

8th a perspective view of two ramp elements of the crankshaft pulley;

9 a perspective view of an adjusting ring of the crankshaft pulley;

10 a perspective view of a Verstellkäfigs the crankshaft pulley and

11 a perspective view of a freewheel inner ring of the crankshaft pulley.

In the 1 to 11 is a crankshaft pulley according to the invention 1 shown in different representations or views or individual parts. The crankshaft pulley 1 includes a pulley track 2 , which is also abbreviated as pulley or belt track, and serves to couple a belt of a belt drive with other units which are arranged in the belt drive. The other units are, for example, an electric motor or a generator, in particular a starter generator, or an ancillary unit, such as an air conditioning compressor of an air conditioner.

The crankshaft pulley 1 is in the drive train of a motor vehicle, as for example in the German patent application DE 10 2007 021 233 A1 is disclosed on a crankshaft 4 attached, which is about a rotation axis 5 is rotatable. The motor vehicle can with the help of the crankshaft pulley according to the invention 1 be operated in a so-called start / stop operation. In the motor vehicle may be a hybrid vehicle with an internal combustion engine and an electric machine, which is designed in particular as a generator. Optionally, the hybrid vehicle may be driven solely by the internal combustion engine or alone with the electric machine.

Into the crankshaft pulley 1 is a pulley freewheel 6 integrated, which also as a boost freewheel 6 referred to as. The crankshaft pulley 1 further includes a planetary gear 10 that is radially outside the boost freewheel 6 is arranged. The planetary gear 10 includes a ring gear 11 with which planetary gears 12 combing on a planet carrier 13 are rotatably mounted. The planet wheels 12 Comb further with a sun gear 14 that together with the ring gear 11 , the planet wheels 12 and the planet carrier 13 into the crankshaft pulley 1 is integrated.

The crankshaft pulley according to the invention 1 further includes a starter freewheel 20 with freewheel rollers 22 , The freewheel rollers 22 are in an adjustable cage 24 guided. The starter freewheel 20 further includes an outer ring 25 with integrated double ramps. The adjustable cage 24 is relative to the outer ring 25 rotatable with the ramps. When turning the adjustment cage 24 become the freewheel rollers 22 , which are also referred to as pinch rollers, brought in one or the other direction of rotation with the ramps in contact, whereby the starter freewheel 20 its closing direction or reverse direction changes.

The associated blocking positions or closed positions of the starter freewheel 20 are also referred to as torque transfer positions. In addition to the two torque transmission positions, the starter freewheel has a third neutral position in which the starter freewheel 20 no torque can be transmitted in both directions. In the neutral position of the starter freewheel 20 a stationary climate operation can be realized, wherein the planetary gear 10 gone crazy.

The planetary gear 10 is partly from a gearbox 26 surrounded, which is preferably designed as a sheet metal part. The gearbox 26 is outside of a motor housing part 28 attached, relative to the crankshaft pulley 1 fixed. In the motor housing part 28 For example, it is a part of a crankcase of the internal combustion engine of the motor vehicle. On the motor housing part 28 is also a lid 29 attached to the crankshaft pulley 1 closes towards the crankcase. The lid 29 can be part of the crankcase.

The freewheel rollers 22 the starter freewheel 20 are in the radial direction between the outer ring 25 and the ring gear 11 arranged, which has an inner ring of the starter freewheel 20 represents. The ring gear 11 of the planetary gear 10 is with the help of a sliding bearing 30 relative to the planet carrier 13 rotatably mounted. The starter freewheel 20 is with the help of an electric motor 34 switched between its two torque transmission positions and its neutral position. The electric motor 34 is equipped with a reduction gear and includes an adjusting gear 35 that with an external toothing 36 meshes, which at a gearing section 38 of the adjustment cage 24 is trained.

To start the internal combustion engine, the belt drive is braked by the starter generator. Then the adjustment cage 24 through the electric motor 34 rotated with the integrated reduction gear in the associated torque transmission position. In this torque transmission position locks the starter freewheel 20 so that the belt trace 2 over the planetary gear 10 with a three to one ratio the crankshaft 4 drives to start the engine. This is the boost freewheel 6 outdated.

After starting the engine, the adjustment cage 24 with the help of the electric motor 34 switched back to its neutral position for regenerative operation. Alternatively, the starter freewheel 20 with the help of the electric motor 34 in his other torque transmission position be switched to allow a high drive with the translation three to one. All three positions of the starter freewheel 20 be kept stable by detents. In the neutral position of the starter freewheel 20 become the freewheel rollers or pinch rollers 22 so far leveraged that, taking into account all tolerances, the pinch rollers 22 and the ring gear 11 do not touch. As a result, a friction-related wear can be minimized.

The boost freewheel 6 , which is also referred to as a pulley freewheel, is between the sun gear 14 and the crankshaft 4 arranged. By (not shown) springs is the boost freewheel 6 biased in a preferred end position in which the torque in the generator mode of the crankshaft 4 on the belt track 2 can be transferred. In this end position, the boost freewheel 6 be overhauled for the stationary climate operation and the starting process.

The boost freewheel 6 includes an inner ring 41 and an outer ring 42 , The inner ring 41 the boost freewheel 6 is with the help of a mounting screw 44 , which is also referred to as the central screw, together with the planet carrier 13 firmly with the crankshaft 4 connected. By interlocking Axialverzahnungen a rotationally fixed connection between the inner ring 41 , the planet carrier 13 and the crankshaft 4 created. The outer ring 42 is stuck with the belt track 2 connected. From the belt track 2 extends a connecting flange 60 radially inward to the outer ring 42 , A relative rotation between the inner ring 41 and the outer ring 42 is through a rolling bearing 45 allows, which is designed as a double-row deep groove ball bearings.

In 11 is the inner ring 41 the boost freewheel 6 shown in perspective alone. In this illustration you can see that the inner ring 41 radially outward flattening 50 has, in the circumferential direction with double ramps 51 . 52 are provided. The inner surface of the outer ring 42 is round. By the execution of the ramps 51 and 52 is ensured in a simple way that the boost freewheel 6 by the occurring during operation centrifugal force engages even at high speeds. The inner ring 41 includes radially outer raceways 54 . 55 for the rolling elements of the rolling bearing 45 ,

The boost freewheel 6 includes an adjustment cage 62 that indirectly by an electric motor 64 is rotatable to the boost freewheel 6 switch. The electric motor 64 is equipped with a reduction gear and includes an adjusting gear 65 that with an external toothing 66 meshes, which at a gearing section 68 is trained. The toothing section 68 is integral with an adjusting ring 70 connected.

The adjusting ring 70 acts with a first ramp element 71 together. The first ramp element 71 is preferably designed as a ramp plate and engages radially outside in a first ramp groove 73 radially inward on the adjusting ring 70 is trained. A second ramp element 72 is preferably also designed as a ramp plate and engages radially inside a second ramp groove 74 who, how to get in 7 sees, on the adjustable cage 62 is provided.

The first ramp element 71 is with the help of leaf springs 75 rotatable, but axially limited displacement, with the lid 29 or the motor housing part 28 connected. The first ramp element 71 is furthermore with an outer ring 78 a rolling bearing 80 connected. An inner ring 81 of the rolling bearing 80 is with the second ramp element 72 connected. Through the rolling bearing 80 becomes a relative rotation between the two ramp elements 71 . 72 allows.

When the adjustable cage 62 is rotated from its previously described preferred stable end position in the other end position, so transmits the boost freewheel 6 the torque in the other direction. Then you can boost the engine by the starter generator with the translation one to one. As a result, for example, a traction help can be realized in a simple manner. Adjusting the boost freewheel 6 done by the electric motor 64 , The mechanism when adjusting the boost freewheel 6 will according to the description of 9 continued.

In 7 you see, that the adjustment cage 62 a circular disk-like basic body 90 has, from the radially outward three driver and / or guide elements 91 to 93 extend in the axial direction. Each of the driver and / or guide elements 91 to 93 includes a second ramp groove, which in 3 With 74 is designated. The driver and / or guide elements 91 to 93 extend from the main body 90 of the adjustment cage 62 to the sun wheel 14 on the outer ring 42 is trained.

In 5 is with 100 denotes a location at which the second ramp element 72 in the second ramp groove 74 engages the adjusting cage 62 is trained. In 5 are also two axial guides 101 . 102 indicated by the second ramp element 72 in the axial direction in the planet carrier 13 is guided. The second ramp element 72 further comprises a ring body 105 that is attached to the inner ring 81 of the rolling bearing 80 is applied.

From the ring body 105 are radial tabs 106 Angled, the inner ring 81 of the rolling bearing 80 partially surround. From the planet carrier 13 are radially outside stop elements 107 . 108 for compression springs (not shown) of the integrated torsional vibration damper of the crankshaft angled. The compression springs allow damping of torsional vibrations or rotational irregularities during operation of the crankshaft pulley 1 , The planet carrier 13 also has an axial toothing on one end face 110 on to the planet carrier 13 non-rotatable with the crankshaft 4 connect to.

In 6 you can see that the adjustable cage 62 a cage body 114 having, for receiving pinch rollers or freewheel rollers 116 (please refer 2 ) of the boost freewheel 6 serves.

In 8th are the two ramp elements 71 . 72 together with the leaf springs 75 shown in perspective. The first ramp element 71 has radially outward three ramp-like guide plates 121 on, with which the ramp element 71 in the first ramp groove 73 engages, which, how to get in 9 sees, is designed as a spiral groove.

The second ramp element 72 has radially inside three guide tabs 122 on, each in a second ramp groove 74 intervene on the adjustment cage 62 is trained. The second ramp element 72 further includes axial guide tabs 124 . 125 that serve the second ramp element 72 on the axial guides 101 . 102 in the planet carrier 13 (please refer 6 ) respectively.

In 9 you can see that the adjusting ring 70 a ring body 130 in which the first ramp groove designed as a spiral groove 73 is trained. From the ring body 130 the toothing section extends 68 with the external teeth 66 radially outward.

In 10 you can see that the adjustable cage 24 a cage body 140 includes. The cage body 140 serves to accommodate or guide the freewheel rollers or pinch rollers 22 the starter freewheel 20 ,

Adjusting the boost freewheel 6 can with the help of the electric motor 64 be carried out as follows. About the adjusting gear 65 can the adjusting ring 70 be twisted, making the first ramp element 71 undergoes an axial movement. The first ramp element 71 is doing by the leaf springs 75 held against twisting. The axial movement of the first ramp element 71 is about the rolling bearing 80 on the second ramp element 72 transfer. The axial movement of the second ramp element 72 in turn, causes the Verstellkäfig 62 twisted in the desired direction.

LIST OF REFERENCE NUMBERS

1

Crankshaft pulley

2

belt track

4

crankshaft

5

axis of rotation

6

Boost freewheel

10

planetary gear

11

ring gear

12

planetary gears

13

planet carrier

14

sun

20

Starter freewheel

22

Idlers

24

Verstellkäfig

25

outer ring

26

gearbox

28

Motor housing part

29

cover

30

bearings

34

electric motor

35

recliner

36

external teeth

38

toothed section

41

inner ring

42

outer ring

44

Mounting screw

45

roller bearing device

50

flattening

51

ramp

52

ramp

54

career

55

career

60

connecting flange

62

Verstellkäfig

64

electric motor

65

recliner

66

external teeth

68

toothed section

70

adjusting

71

first ramp element

72

second ramp element

73

first ring groove

74

second annular groove

75

leaf springs

78

outer ring

80

roller bearing

81

inner ring

90

body

91

Carrier and / or guide element

92

Carrier and / or guide element

93

Carrier and / or guide element

100

Job

101

axial guidance

102

axial guidance

105

ring body

107

stop element

108

stop element

110

axial toothing

114

cage body

116

Idlers

121

ramp-like guide strap

122

guide tab

124

axial guide tab

125

axial guide tab

130

ring body

140

cage body

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0782674 B1 [0002]
• EP 0980479 B1 [0002]
• DE 102007021233 A1 [0015, 0029]

Claims (10)

Crankshaft pulley for transmitting a torque between a crankshaft ( 4 ) and a belt drive, with a planetary gear ( 10 ) and at least one starter freewheel ( 20 ), Characterized in that the starter freewheel ( 20 ) between a ring gear ( 11 ) of the planetary gear ( 10 ) and a motor housing part ( 28 ) is arranged. Crankshaft pulley according to claim 1, characterized in that the starter freewheel ( 20 ) has two stable torque transmitting positions in opposite directions of rotation. Crankshaft pulley according to one of the preceding claims, characterized in that the starter freewheel ( 20 ) has a stable neutral position to allow generator operation and / or ancillary unit operation. Crankshaft pulley according to one of the preceding claims, characterized in that the starter freewheel ( 20 ) by an electric motor ( 34 ) is switchable, which on the motor housing part ( 28 ) is attached. Crankshaft pulley according to claim 4, characterized in that the starter freewheel ( 20 ) via an adjustment cage ( 24 ) by the electric motor ( 34 ) is switchable. Crankshaft pulley according to one of the preceding claims, characterized in that a booster freewheel ( 6 ) between a sun wheel ( 14 ) of the planetary gear ( 10 ) and the crankshaft ( 4 ) is arranged. Crankshaft pulley according to claim 6, characterized in that the booster freewheel ( 6 ) has two stable torque transmitting positions in opposite directions of rotation. Crankshaft pulley according to claim 6 or 7, characterized in that the booster freewheel ( 6 ) by a further electric motor ( 64 ) is switchable, which on the motor housing part ( 28 ) is attached. Crankshaft pulley according to claim 8, characterized in that the booster freewheel ( 6 ) via an adjusting ring ( 70 ) by the further electric motor ( 64 ) is switchable. Crankshaft pulley according to claim 9, characterized in that the adjusting ring ( 70 ) radially outside a toothed portion ( 68 ) with an external toothing ( 66 ) and / or radially inside a spiral groove ( 73 ) having.

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