DE102009016164A1 - Coupling for use in automobile industry to connect belt pulley of crankshaft with rotor hub of generator in internal combustion engine, has blocking element preventing locking of locking element in recess during exceeding of hub limit speed - Google Patents

Abstract

The coupling has a locking element (36) for releasing a lock between a belt pulley (25) and a rotor hub (26) against reset force during exceeding of limit speed of the belt pulley. The locking element is locked in a locking recess (37) in the hub in an idle state of the belt pulley and the hub, such that rotation of the belt pulley with respect to the hub is prevented. A blocking element (38) is activatable by rotation of the hub and prevents locking of the locking element in the locking recess during exceeding of limit speed of the hub. An independent claim is also included for a method for coupling a generator of an internal combustion engine with a crankshaft of the internal combustion engine.

Description

Field of the invention

The The invention relates to a coupling for connecting a rotatable Outer element with a rotatably mounted inner element. The invention also relates to a method for coupling a generator with a crankshaft.

Background of the invention

conditioned by the increasing aspirations of the automobile industry, the average fuel consumption to reduce, for example, in an internal combustion engine a belt-driven starter generator used. This novel technology comes preferably in combination with petrol or diesel engines with direct injection used. Due to the unfavorable Engine dynamics, which have such engines, is the desire near, a traction drive with a generator freewheel pulley (OAP, Overrunning Alternator Pulley). The proven mode of operation of a generator freewheel should be used.

Such a combined with a pulley freewheel is for example from the document DE 195 11 188 A1 known. Such a freewheel transmits the moments of the traction mechanism drive generated by the crankshaft to an input shaft of the auxiliary unit. The freewheel pulley reduces the non-uniformities resulting from the crankshaft by partially "slipping". This behavior is undesirable when using a starter as an accessory. This represents a special accessory insofar as the torque transfer is reversed from the accessory to the crankshaft. It is therefore necessary to rotatably connect the generator with the pulley in the starting phase.

On the other hand, it is necessary after the start phase for an optimal functioning of the generator to provide for this a possible uniform drive, which can be done via a freewheel. The in the DE 44 34 324 The proposed solution, to use a hydrostatic coupling to couple ancillary units in a drive unit, is eliminated because in the start phase not necessarily a hydraulic pressure must prevail.

The DE 103 22 230 A1 shows a device for damping torsional vibrations in a traction drive for auxiliary units of an internal combustion engine, with a one-way clutch, which is arranged between a pulley and a hub. Between the pulley and the hub is, axially behind the one-way clutch, a locking device. This has a surrounding the hub and attached to this inner ring, a surrounding the inner ring with radial clearance, attached to the pulley outer ring and a plurality of locking balls, which are arranged together with compression springs in radial bores of the outer ring. In this locking device occurs when stopping the internal combustion engine and thus braking the outer ring to a locking due to reduced centrifugal force falling arresting balls, although the additional assembly shaft still rotates at significant speeds. This abrupt intervention leads to considerable stress, which may have a life-reducing effect.

The DE 10 2004 040 810 A1 discloses a device for damping torsional vibrations in a drive train with a one-way clutch, which is arranged between a pulley and a hub of a rotor, wherein the hub with an input shaft of an auxiliary unit and the pulley are connected via a traction means with a crankshaft and the overrunning clutch one Hub surrounding and attached to this inner ring and a ring surrounding the inner ring with radial clearance, attached to the pulley outer ring, wherein at least one centrifugal force actuated locking element and in the outer ring at least one locking receptacle are arranged in the inner ring. In this type of locking a lock is tuned while tuned to the speed of an additional power unit shaft, but this design is structurally complex and expensive.

Object of the invention

Of the The invention is therefore based on the object of specifying a coupling, which has a high level of operational reliability with a long service life and at the same time is inexpensive. Further task of The invention is the specification of a method for coupling a generator with a crankshaft, which is particularly reliable.

Description of the invention

The object directed to a coupling is achieved according to the invention by specifying a coupling for connecting a rotatable outer element with a rotatably mounted inner element, with a locking element which releases a locking between the outer element and the inner element against a restoring force when an outer element limit speed is exceeded, then that a free rotation of the outer element is made possible with respect to the inner element and which at standstill of the outer element and the inner element in a Verriegelungsaus recess is locked in the inner member and thus prevents rotation of the outer member relative to the inner member, wherein an activatable by rotation of the inner member locking element is provided which prevents locking of the locking element in the locking recess above an inner element limit speed.

By this embodiment is the first time provided a coupling, the tuned at a locking on the speed of the inner element only is subjected to adjustable, defined forces, wherein at the same time an unlocking dependent on a limit speed of the outer element is effected. This allows So both the release and the lock on a specific operating situation at certain speeds of rotation of the interior and the outer element can be adjusted. Through the interaction a locking element in the outer element on the one hand with a by the rotational speed of the inner element activated blocking element On the other hand, therefore, both z. B. a defined drive phase be enabled, in which the inner element of the outer element drives up to a limit speed, as well as a safe lock-in phase be enabled, with a lock up to below a limit speed of the inner member is locked.

Preferably is the locking element is guided in a channel, which is formed in the outer element, wherein a spring in the channel is arranged so that it opposes the centrifugal force the locking element acts. The locking element is doing while pressed by the spring in the locked position the centrifugal force by the rotation of the outer element that Locking element drives in an unlocked position. The suitable Selection of the spring constant and the mass of the locking element thus enables unlocking at a defined Rotation speed.

Prefers the blocking element is activated by a centrifugal force. hereby The setting of the inner element limit speed becomes much easier Way too accessible because z. B. only the mass of the blocking element must be adjusted.

preferred dimensions the blocking element is arranged in the locking recess and fastened with a fastener so that it thereby at Reaching or exceeding the internal element limit speed is held in a locked position. The fastener could z. B. be a wire through which the blocking element with the inner element connected is.

Preferably the blocking element is arranged in the locking recess and becomes when reaching or exceeding the inner element limit speed held by a stop in a locked position. In such a Design, the locking element loose in the locking recess be held and is at the inner element limit speed is exceeded pushed outwards against the stop, causing the locking recess against engagement of the locking element is locked. More preferably, the stop is by a Locking element cage formed, which with a cage opening over the locking recess extends and thus the opening the locking recess is reduced so that for the Blocking a stop is formed while at the same time the locking element through the cage opening can engage in the locking recess. The locking element cage can z. B. be plastic and fitting over the inner element be added or clamped, where he may still z. B. by attached a gluing and in particular secured against twisting can be.

preferred dimensions is the blocking element by one of the different speed Friction force resulting from outer element and inner element enableable. Further preferred is the blocking element as a Friction disc formed between the outer element and Internal element rubbing is arranged so that one of a speed difference between outer element and inner element the following frictional force acts on the blocking element in the direction of the blocking position and at the same time a return spring against the frictional force the blocking element is arranged to act. A speed difference between the outer element and the inner element thus leads to a defined force on the blocking element, caused by the friction exerted on the blocking element. Especially advantageous here is that the activation of the blocking element does not depend of an absolute speed of the inner element but dependent from the relative speed of the inner element to the outer element is. As a result, z. B. the inner element limit speed higher be because the forces caused by a locking forces from the relative movement of the outer element to the inner element depend. A secure locking can with rotating outer element So even for higher speeds of the inner element take place, against activation of the blocking element solely due to the absolute speed of the inner element.

Preferably, the inner member has an end face and an outer circumference in which the locking recess is arranged, wherein the friction disc is arranged on the end face and engages around the outer circumference with a locking collar so that the locking catch in the locking position covers the locking recess. The friction disc is thus rotatably mounted, for. B. via a Achsan set on the inner element and rubs on the one hand on the end face of the inner element and with its opposite surface on the outer element. Above a limit speed difference between inner and outer member, the friction force exceeds the spring force of the return spring and the friction disc (the locking member) is twisted. As a result, the Sperransatz is moved and pushes over the locking recess, that locking of the locking element is prevented.

preferred dimensions is a plurality of locking elements and an equal number provided by blocking elements. In particular, the locking elements uniform over an outer circumference of the Inner element distributed, each locking element exactly one blocking element is assigned.

Prefers is the clutch in a drive train of a traction mechanism drive an internal combustion engine arranged for coupling an additional unit, wherein the inner element with an input shaft of the additional unit and the outer element via a traction device directly or indirectly connected to a crankshaft of the internal combustion engine are. More preferably, the additional unit is a generator, the to start the internal combustion engine is used. Preferably is an additional one-way clutch provided between a pulley and a hub of a rotor is arranged, wherein the hub with an input shaft of the generator and the pulley over a traction means are connected to the crankshaft.

preferred dimensions has the locking recess in the region of its opening a chamfer so that thereby locking a the locking element is facilitated. This chamfer can be provided on one side so that they correspond to the direction of rotation of the. Crankshaft facing the einrehenden locking element Side of the locking recess is located.

The A task directed to a method is achieved according to the invention by specifying a method for coupling a generator of an internal combustion engine with a crankshaft of the internal combustion engine, by means of a clutch, having a locking element, wherein in a starting phase of Generator the internal combustion engine by driving the crankshaft starts while in the starting phase, the locking element is in a locked state and thereby the coupling of the Generator via a generator shaft with the crankshaft produces, wherein the locking element against a restoring force when a crankshaft limit speed is exceeded Lock between the crankshaft and a generator shaft releases and wherein a activatable by rotation of the generator shaft blocking element is provided, which is a locking of the locking element in a locking recess above a generator limit speed prevented and only when reaching or falling below the generator limit speed the Locking recess releases, so that the locking element can lock.

The Advantages of such a method correspond to the o. G. benefits the coupling according to the invention.

Brief description of the drawings

The Invention will be described below with reference to a particularly advantageous Embodiment explained in more detail and shown in the accompanying drawings. Show it:

1 a longitudinal section of a coupling according to the prior art

2 a longitudinal section of a coupling according to the invention

3A a cross section of the device according to the invention along the section line III-III before the starting process of the internal combustion engine

3B a longitudinal section of a coupling with a schematic representation of the locked state according to 3A

4A a cross section of the device according to the invention along the section line III-III after the starting process of the internal combustion engine

4B a longitudinal section of a coupling with a schematic representation of the unlocked state according to 4A

5 a cross-section of the device according to the invention along the section line III-III before the starting process of the internal combustion engine with bevelled locking recess

6 a cross section of the device according to the invention along the section line III-III after the starting process of the internal combustion engine with loosely mounted locking elements

7A a cross section of the device according to the invention along the section line III-III after the starting operation of the internal combustion engine with held by a cage locking elements

7B the cage off 7A in a side view

8A a view of a erfindungsge Permitted device with a designed as a friction disc blocking element

8B a cross section through the device according to 8A

Detailed description the drawings

An in 1 illustrated prior art coupling 50 surrounds an input shaft 1 an auxiliary unit, not shown, in particular a generator. The input shaft 1 is via a pulley 2 and a traction means not shown in detail driven by a driven pulley, which is connected to the crankshaft of an internal combustion engine. The pulley 2 has a reinforcing ring in its interior 3 on. In a hole 4 This ring is one of a one-way clutch 5 and two cylindrical roller bearings 6 and 7 existing unit used. Here are the unit a common bearing outer ring 8th and a common bearing inner ring 9 intended. The bearing inner ring 9 has a plurality of circumferentially spaced, not shown clamping ramps, which with a corresponding number of clamping rollers 10 interact. The pinch rollers are in a cage 11 guided and biased by means not shown springs against the clamping ramps. The bearing outer ring 8th is substantially sleeve-shaped and has over its entire length a constant inner diameter, where it tracks for the cylindrical roller bearings 6 and 7 as well as the pinch rollers 10 forms.

The bearing inner ring 9 is at its end remote from the accessory end with a radially outwardly directed board 12 provided, the front side of a thrust washer 13 supported, which in the reinforcing ring 3 is fixed. At its other axial end, the bearing inner ring 9 one shoulder 14 on, for example, is tooth-like and in individual longitudinal grooves 15 engages, which in turn is part of a hub 16 are. At one end has the bearing outer ring 8th a first board 17 from the board 12 of the bearing inner ring 9 is engaged behind. A second board 18 of the bearing outer ring 8th , which is provided at the additional unit facing the end, engages behind a cage 19 of the cylindrical roller bearing 7 , This second board 18 adjacent is a radial seal 20 arranged in the pulley 2 is inserted and a sliding seal with the bearing inner ring 9 forms. For the purpose of attaching the hub 16 on the input shaft 1 has the hub 16 an internal thread 21 on, being inside the hub 16 at a distance to this internal thread 21 a splined tooth profile designed as serration 22 is intended for an attack of an assembly tool. The pulley 2 is at its end facing away from the additional unit by means of a lid 23 closed, which has an axially projecting edge 24 having. This is on the circumference of the pulley 2 snapped.

An illustrated in the following figures, inventive coupling 50 is essentially the same as the one in 1 illustrated coupling 50 , It differs from this, however, in that a limit speed clutch 33 is provided, the z. B. on an end face of the coupling 50 , the input shaft 1 arranged around, as in 2 shown schematically. An exterior element 25 is here formed by a pulley, corresponding to the pulley 2 of the 1 and an interior element 26 through a hub, according to the hub 16 of the 1 , The limit speed clutch 33 on the one hand serves to drive the outer element 25 through the inner element 26 to allow by means of a lock, in particular for a designed as a generator auxiliary unit which drives the crankshaft in the starting phase of an internal combustion engine and thus starts the internal combustion engine. On the other hand, by the limit speed clutch 33 ensures that locking in a stop phase only at a permissible speed of the inner element 26 is possible to avoid high loads by an abrupt braking of the input shaft. This will be explained in more detail with reference to the following figures.

3A shows a cross section of the limit speed clutch 33 along the section line III-III before the starting process of the internal combustion engine. The outer element 25 has a circular inner recess in which the inner element 26 rotatable to the outer element 25 is stored. In the outer element 25 are circumferentially equally distributed channels 40 arranged, formed as having a respective opening of the inner recess extending blind holes. In each of the channels 40 is a spiral spring 42 arranged at the channel end, to each of which a locking element 36 followed. The feathers 42 push the locking elements 36 towards the channel exit. The locking elements 36 engage in locking recesses, as in the standstill shown here 37 in the interior element 26 one. The formed as a radially extending channels locking recesses 37 each contain a blocking element 38 whose function is based on 4 will be described in detail. 3B shows a cross section through the coupling 50 in the starting phase, in, as in 3A , the locking elements 36 are locked. The limit speed clutch 33 is shown schematically as a closed lock. Is the input shaft 1 a generator shaft, so can by the closed limit speed clutch 33 a power flow from the input shaft 1 on the pulley 2 take place, which in turn drive a crankshaft via a belt and thus can start the engine.

4A shows the limit speed clutch of 3A in an unlocked state. The outer element turns 26 at a speed greater than the outer element limit speed, whereby the locking elements 36 by the centrifugal force against the spring force of the springs 42 outwards and out of the locking recesses 37 be pressed out. Now stop the outer element 26 , For example, by stopping the internal combustion engine, so the inner member rotates 26 initially due to inertia. An abrupt locking of the locking elements 36 in the locking recesses 37 would lead to high forces and possibly damage. The blocking elements 38 prevent this locking, in which they centrifugal force due to the further rotation of the inner element 26 be driven to the outside and thereby the openings of the locking recesses 37 against locking the locking elements 36 block. They are by fasteners 41 held. Only when reaching or falling below an inner element limit speed, the centrifugal force on the locking elements 36 so small that the springs 42 the locking elements 36 in the locking recesses 37 can press. This ensures that locking does not cause unduly high loads.

In 4B is the power flow for the open limit speed clutch 33 shown. Here is the pulley 2 the input shaft 1 over the overrunning clutch 5 driving in a conventional manner.

5 shows a limit speed clutch 33 as in 3A , where here the locking recesses 37 one side are so bevelled that a sliding in of the locking elements 36 is relieved.

In 6 is another variant of a limiting speed clutch 33 shown. Here are the locking elements 38 hat-shaped and loose in the locking recesses 37 guided. At the openings of the locking recesses 37 are heels 44 so formed that they match the skin edges of the locking elements 38 interact and these are held there under centrifugal force. Separate fasteners are thus for the locking elements 36 not necessary.

In 7A is one too 6 shown comparable variant, here instead of the attacks 44 a plastic cage 45 over the interior element 26 pressed. The cage 45 can also z. B. glued. He has cage openings 46 so that they come to rest over the locking recesses and limit these in diameter. As a result, ball-shaped blocking elements 38 under centrifugal force in the locking recesses 37 held. At the same time, the locking elements 36 so big that they go through the cage openings 46 through into the locking recesses 37 can engage when the locking elements 36 release an intervention. 7B shows the plastic cage 45 in a side view.

Another possibility, an engagement of the locking elements 36 To lock, consists in the design of the blocking element 38 as a friction disk. This is in the 8A and 8B (Cross section to 8A ). The blocking element 38 is by one of the different speed of outer element 25 and interior element 26 resulting friction force can be activated and is between the outer element 25 and interior element 26 frictionally arranged so that one of a speed difference between outer element 25 and interior element 26 following frictional force on the blocking element 38 towards the locking position and at the same time a return spring 48 against the frictional force on the blocking element 38 is arranged acting. A speed difference between the outer element 25 and the interior element 26 thus leads to a defined force on the blocking element 38 , caused by the on the blocking element 38 applied friction. It is particularly advantageous here that the activation of the blocking element 38 not dependent on an absolute speed of the inner element 26 but depending on the relative speed of the inner element 26 to the outer element 25 is. As a result, z. B. the inner element limit speed be higher, since the forces caused in a locking forces of the relative movement of the outer element 25 to the interior element 26 depend. A secure locking can ment with rotating Außenele 25 So even for higher speeds of the inner element 26 take place, against activation of the blocking element 38 solely due to the absolute speed of the inner element. The interior element 26 has an end face 51 and an outer circumference 52 on, in which the locking recesses 37 are arranged. The friction disc 38 is at the frontal area 51 arranged and surrounds with Sperransätzen 47 the outer circumference 52 so that the lock rates 47 in the locked position, the locking recess 37 cover. The friction disc 38 is rotatably mounted via an axle 53 on the interior element 26 and rubs on the one hand on the face 51 of the inner element 26 and with its opposite surface on the outer element 25 , Above a limit speed difference between inner and outer element, the frictional force exceeds the spring force of the return spring 48 and the friction disc 38 (the blocking element) is twisted. This will also the Sperransätze 47 moved and push so on the locking recesses 47 in that a locking of the locking elements 36 is prevented.

1

input shaft

2

pulley

3

reinforcing ring

4

drilling

5

Overrunning clutch

6

Cylindrical roller bearings

7

Cylindrical roller bearings

8th

Bearing outer ring

9

Bearing inner ring

10

pinch roller

11

Cage

12

shelf

13

thrust washer

14

shoulder

15

longitudinal groove

16

hub

17

first shelf

18

second shelf

19

Cage

20

Radial seal

21

inner thread

22

Multi-tooth profile

23

cover

24

edge

25

male member

26

inner element

27

Overrunning clutch

28

Bearing outer ring

29

Bearing inner ring

30

pinch roller

31

roller bearing

32

roller bearing

33

Limit speed clutch

34

35

36

locking element

37

locking receptacle

38

blocking element

39

40

channel

41

fastener

42

feather

43

bevel

44

attack

45

Locking element cage

46

cage opening

47

locking lug

48

Return spring

49

50

clutch

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• DE 19511188 A1 [0003]
• - DE 4434324 [0004]
• - DE 10322230 A1 [0005]
• DE 102004040810 A1 [0006]

Claims (15)

Coupling for connecting a rotatable outer element ( 25 ) with a rotatably mounted inner element ( 26 ), with a locking element, which against a restoring force when exceeding a Außenelelement-limiting speed, a lock between the outer element ( 25 ) and the inner element ( 26 ), so that a free rotation of the outer element ( 25 ) relative to the inner element ( 26 ) and which at standstill of the outer element ( 25 ) and the inner element ( 26 ) in a locking recess in the inner element ( 26 ) and thus turning the outer element ( 25 ) relative to the inner element ( 26 ), characterized in that a by rotation of the inner element ( 26 ) activatable locking element is provided which prevents locking of the locking element in the locking recess above an inner element limit speed. Coupling according to claim 2, characterized in that the locking element is guided in a channel, which in the outer element ( 25 ) is formed, wherein a spring in the channel is arranged so that it acts against the centrifugal force on the locking element. Coupling according to claim 1, characterized in that that the blocking element can be activated by a centrifugal force. Coupling according to Claim 1, 2 or 3, characterized that the blocking element is arranged in the locking recess and is fastened with a fastener such that it thereby upon reaching or exceeding the inner element limit speed is held in a locked position. Coupling according to claim 3, characterized that the blocking element is arranged in the locking recess and upon reaching or exceeding the inner element limit speed through a stop is held in a locked position. Coupling according to claim 5, characterized in that that the stop is formed by a cage, which is with a cage opening via the locking recess extends and thus the opening of the locking recess so reduced that formed a stop for the blocking element is while at the same time the locking element the cage opening through into the locking recess can intervene. Coupling according to claim 1, characterized in that the blocking element by one of the different rotational speed of outer element ( 25 ) and inner element ( 26 ) friction force can be activated. Coupling according to claim 7, characterized in that the blocking element is designed as a friction disc, which between outer element ( 25 ) and inner element ( 26 ) is arranged so that one of a speed difference between outer element ( 25 ) and inner element ( 26 ), the following frictional force acts on the blocking element in the direction of the blocking position, and at the same time a restoring spring is disposed against the frictional force acting on the blocking element. Coupling according to claim 8, characterized in that that the inner element has an end face and an outer circumference in which the locking recess is arranged, wherein the friction disc is arranged on the end face and with a Sperransatz the outer circumference so engages that the Sperransatz in the locked position covering the locking recess. Coupling according to claim 5, characterized in that that a plurality of locking elements and an equal number is provided by blocking elements. Coupling according to one of the preceding claims, characterized in that it is arranged in a drive train of a traction mechanism drive of an internal combustion engine for coupling an additional unit, wherein the inner element ( 26 ) with an input shaft ( 1 ) of the auxiliary unit and the outer element ( 25 ) are connected via a traction means directly or indirectly with a crankshaft of the internal combustion engine. Coupling according to claim 11, characterized in that that the additional unit is a generator for starting the internal combustion engine serves. A coupling according to claim 12, comprising an additional one-way clutch ( 27 ) between a pulley ( 25 ) and a hub ( 26 ) of a rotor, wherein the hub ( 26 ) with an input shaft ( 1 ) of the generator and the pulley ( 25 ) are connected via a traction means with the crankshaft. Coupling according to one of the preceding claims, when the locking recess in the region of its opening has a bevel so that thereby a locking the locking element is facilitated. Method for coupling a generator of an internal combustion engine with a crankshaft of the internal combustion engine, by means of a clutch, the Locking element, wherein in a start phase of the generator, the internal combustion engine by driving the crankshaft starts, while in the starting phase, the locking element is in a locked state and thereby produces the coupling of the generator via a generator shaft with the crankshaft, wherein the locking element against a restoring force at Exceeding a crankshaft limit speed releases the locking between the crankshaft and a generator shaft, characterized in that a by activating the generator shaft activatable locking element is provided which prevents locking of the locking element in a locking recess above a generator limit speed and only when reaching or falling below the Generator limit speed releases the locking recess, so that the locking element can lock.