CN113365859A

CN113365859A - Belt pulley clutch

Info

Publication number: CN113365859A
Application number: CN201980089008.0A
Authority: CN
Inventors: 约翰内斯·博塞特; 沃尔夫冈·哈斯; 多米尼克·汉斯; 马丁·福内姆
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2019-01-14
Filing date: 2019-12-16
Publication date: 2021-09-07
Also published as: DE102019100737A1; WO2020147878A1

Abstract

A pulley clutch (1) having at least an input shaft (2) and a pulley (3) which is connected to the input shaft (2) in a switchable manner via the pulley clutch (1), and a first non-actuatable pawl device (4) and a second actuatable pawl device (5), wherein only a torque (7) of the input shaft (2) can be transmitted to the pulley (3) via the first pawl device (4) in a first direction of rotation (6) of the pulley (3) and the input shaft (2), wherein the torque (7) of the input shaft (2) cannot be transmitted to the pulley (3) at least in a second direction of rotation (8) of the input shaft (2), wherein the second pawl device (5) can be actuated between two switching positions (9, 10), wherein in the first switching position (9) no torque (7) can be transmitted via the second pawl device (5) in both directions of rotation (6, 8), wherein in the second switching position (10) a torque (7) can be transmitted from the pulley (3) to the input shaft (2) only in at least the first direction of rotation (6) of the pulley (3).

Description

Belt pulley clutch

Technical Field

The invention relates to a pulley clutch. Pulley clutches are used in particular for the switchable connection of two drive units (for example an electric machine and an internal combustion engine).

Background

In particular, the pulley clutch is provided for use in a starter/generator pulley in order to be able to effect a decoupling of a (partial) belt drive or a belt in relation to the direction of rotation.

In a stationary state of, for example, an internal combustion engine, a conventional air conditioning installation connected to the crankshaft of the internal combustion engine via a belt drive has no function and is therefore unable to cool the passenger compartment. The problem is of increasing importance as more and more vehicles are equipped with start-stop systems.

The operating principle of a pulley clutch operated without an actuator by means of a centrifugal force actuating element and an inertia actuating element at the crankshaft is described in DE 102016211145 a 1. The centrifugal force switching is effected here by means of a centrifugal mass which is placed within the belt pulley and couples the pawls via a rotational movement relative to the shaft via an additional coupling element.

A disadvantage of the described arrangement is the multi-part construction of the two switching elements (inertial and centrifugal force actuating device), which requires significantly more installation space than in a normal belt pulley. Furthermore, a switching element is required which enables a sliding pivoting movement of the actuating device from the movement of the centrifugal mass. This movement presses the pawls inward toward the axis of rotation, thereby decoupling the pulley from the hub. However, the movement is frictional and causes wear.

A rotation direction adjuster for a crankshaft pulley is known from DE 102017105261 a 1. The rotation direction adjuster can generate forward rotation at the air conditioner compressor from backward rotation at the pulley.

Alternatively, there is the possibility of using an electric air conditioning compressor which can be operated completely independently of the belt drive.

Disclosure of Invention

Starting from this, the invention is based on the object of providing a pulley clutch which is of the simplest possible construction and by means of which two drive units can be switchably connected to one another. In addition, the pulley clutch requires only as little installation space as possible.

Said object is achieved by means of a pulley clutch according to the features of the independent claim. Further advantageous embodiments of the invention are given in the dependent claims. The features listed individually in the dependent claims are combined with one another in a technically meaningful manner and can define further embodiments of the invention. The features specified in the claims are, furthermore, explained and illustrated in greater detail in the description, in which further preferred embodiments of the invention are shown.

The invention relates to a pulley clutch having at least an input shaft and a (first) pulley which is connected to the input shaft in a switchable manner via the pulley clutch, and a first non-actuatable pawl device and a second actuatable pawl device. Via the first detent means, the torque of the input shaft can only be transmitted to the belt pulley when there is a first direction of rotation of the belt pulley and the input shaft, wherein the torque of the input shaft cannot be transmitted to the belt pulley when there is at least a second direction of rotation of the input shaft. The second pawl device can be switched between two switching positions. In the first switching position, no torque can be transmitted in both rotational directions via the pawl device. In the second switching position, torque can be transmitted from the pulley to the input shaft only when there is at least a first direction of rotation of the pulley.

Pulley clutches are used in particular for the switchable connection of two drive units (for example an electric machine and an internal combustion engine).

The input shaft is connected in a rotationally fixed manner, in particular, to a rotor of an electric machine (which can be operated as a generator and as a motor).

The (first) pulley is connected, in particular via a belt, to a second pulley, which is connected in a rotationally fixed manner to a crankshaft of the internal combustion engine.

Via the input shaft, the torque of the electric machine can be introduced into the belt pulley clutch (electric motor operation, for example for starting and accelerating the internal combustion engine). Instead, torque can be transmitted from the pulley clutch via the input shaft to the electric machine (generator operation; torque of the internal combustion engine is introduced into the electric machine).

Via the (first) pulley, in particular, the torque of the internal combustion engine can be introduced into the pulley clutch. The electric machine can be operated as a generator via torque.

The torque proposed here generally relates to a positive torque of the first component, i.e. causing a driving (i.e. acceleration) of the second component.

In particular, it is proposed that the pulley clutch be permanently closed during normal operation of the drive and transmit torque in both directions of action. In addition, the pulley clutch can be disengaged in the opposite direction of rotation of the electric motor in the stationary state of the internal combustion engine, and no torque is transmitted to the crankshaft in this direction.

In particular, the actuation of the pulley clutch should not take place via an additional actuator, but rather the pulley clutch should be opened and closed autonomously at the belt drive in dependence on the state of the electric machine already present in the motor vehicle. In particular, the rotational speed at the input shaft or at a (first) pulley, which is connected via a belt to the crankshaft of the internal combustion engine, and the centrifugal forces occurring there, for example, should be used as control variables.

In the case of very small pulleys at the generator or motor and the small installation space associated therewith, it is often not possible to accommodate a complete mechanical device or a pulley clutch. Here, a simple, form-fitting pulley clutch is required, which is able to transmit torque from the input shaft to the (first) pulley.

The proposed pulley clutch is in particular a clutch acting on both sides via a detent device. The compact and nested design enables the use of the pulley clutch in a very small installation space.

The detent device comprises in particular a detent, via which the two rotatable parts (here the first pulley and the input shaft) can be connected to one another in a rotationally fixed manner (if necessary maintaining a small play). A positive connection between the parts can be produced via the detent and, if necessary, released again. The components in particular have flanges which are respectively opposite one another and which have recesses into which the detent can engage in order to produce a form fit. The detent is in particular pivotable, so that the form fit can be removed. In particular, a freewheeling can be achieved via the pawl of the pawl device.

The form-fitting connection is formed by the nesting of at least two components into one another. The component can thus also be released without interrupting the force transmission or without interrupting the force transmission. In other words, in a form-fitting connection, one connection partner interferes with the other connection partner.

The form fit is in particular dependent on the direction of rotation of the components and on which component transmits the torque to the other component.

The first pawl device acts in particular as a free-wheel mechanism. Via the first detent means, the torque of the input shaft can only be transmitted to the pulley when there is a first direction of rotation of the pulley and the input shaft. The torque present at the pulley cannot be transmitted to the input shaft. In this case, the pulley will rotate faster than the input shaft. In the presence of at least a second direction of rotation of the input shaft, the torque of the input shaft is conversely not transferable to the pulley. In this case, the input shaft rotates faster than the pulley.

In particular, the second detent device can be actuated (exclusively) in relation to the rotational speed.

In particular, the second pawl device is arranged in the first switching position in the non-actuated state (positive fit is not possible), and actuation into the second switching position (positive fit between the two components can occur as a function of the direction of transmission of the torque and the direction of rotation) is carried out as a function of the rotational speed of the input shaft or the belt pulley.

In particular, the centrifugal mass of the centrifugal force actuating device can be moved out of a rest position when the limit rotational speed is exceeded, wherein the second pawl device is actuated as a result of said movement.

In particular, the centrifugal mass can only be moved out of the rest position against the spring force of the preload spring.

In particular, the centrifugal force actuating device has a plurality of centrifugal masses in the circumferential direction, which are coupled to one another via coupling rings, so that the movements of the centrifugal masses are only carried out jointly. The coupling of the centrifugal masses via the coupling ring enables, in particular, a simultaneous actuation of the pawls and a compensation of the gravitational force.

In particular, the pawl of the second pawl device can be moved by a pawl spring from a first switching position into a second switching position, wherein the pawl spring is prestressed by the centrifugal mass in the first switching position.

In particular, the pawl of the first pawl device is pretensioned by a (further) pawl spring, so that the pawl can be set by the pawl spring in a predetermined position in which a form fit can be achieved.

The movement of the pawl from the second switching position or the position in which a positive fit is possible into the first switching position or the position in which a positive fit is not possible takes place in particular against the spring force of the pawl spring.

In particular, the pawls (of the second pawl device and/or of the first pawl device) and the centrifugal mass are connected to the input shaft.

Alternatively, the pawls (of the second pawl device and/or of the first pawl device) and the centrifugal mass are connected to the belt pulley.

The centrifugal mass can likewise be fixed on the pulley when the pawls of the second pawl device are connected to the pulley such that the pawls no longer have their point of rotation at the input shaft but at the pulley (which is connected via a belt, for example, to a crankshaft of an internal combustion engine), whereby the centrifugal force acts on the centrifugal mass only when the pulley is rotating. The pawls of the second pawl device are therefore engaged, i.e., moved into the second switching position, in particular only after the internal combustion engine has started.

When the electric machine is operated in the second direction of rotation (and if necessary when the internal combustion engine is at a standstill), the pawls of the second pawl device are therefore always decoupled, i.e. in the first switching position, independently of the rotational speed of the input shaft. This enables, for example, standard air conditioning to be performed regardless of the rotational speed.

In particular, two pawls (i.e. the pawl of the first pawl device and the pawl of the second pawl device) can also be connected to the belt pulley. This has the advantage that the electric motor can be operated in the second direction of rotation, wherein the pawls of the second pawl device are always decoupled, i.e. in the first switching position, independently of the rotational speed of the input shaft. As a result, the standard air conditioning can also be carried out independently of the rotational speed, wherein additionally the rolling of the first pawl in the freewheeling direction is advantageously carried out. The spring force of the pawl springs of the two pawls must at least compensate for the centrifugal force of the pawls in order to ensure a reliable switching state.

Furthermore, a torque transmission device is proposed, comprising at least: a first pulley arrangement having at least one first pulley and a second pulley, the first and second pulleys being connected to each other via a first belt; and a second pulley arrangement having at least one third and fourth pulley, which are connected to each other via a second belt. The first pulley is connected to the input shaft in a switchable manner via the pulley clutch, wherein the third pulley is connected to the input shaft in a rotationally fixed manner.

In particular, in the torque transmission device, the decoupling of the input shaft from the second pulley, which is connected in particular rotationally fixed to the crankshaft of the internal combustion engine, is possible at low rotational speeds in the opposite rotational direction of the electric motor (i.e. in the second rotational direction), in particular at rotational speeds below the idling rotational speed of the internal combustion engine. In the direction of rotation of the electric motor (i.e. in the first direction of rotation), the pulley clutch is closed permanently (by means of the first pawl device), with the exception of a small backlash.

As a detent device, in particular, the detent device described in DE 102016211145 a1 (with the free-wheel principle) can be used.

The pulley clutch is formed by at least two pawl devices each having opposite pawls (starting pawl and generator pawl), wherein only the generator pawl (pawl of the second pawl device) (opposite to the motor running direction, i.e. in the second rotational direction) is actuated by means of a centrifugal force actuating device.

Preferably, each pulley clutch is designed with two pawl devices, each having a plurality of pawls, which are distributed in a circumferential direction, in particular uniformly and alternately (i.e. the pawls of the first pawl device alternate with the pawls of the second pawl device). In particular, each detent device has at least two, preferably three, in particular more than three detents. The starting pawl (pawl of the first pawl device) rolls over in the opposite rotational direction (second rotational direction) and is in the line of force in the motor running direction (first rotational direction) (i.e. produces a positive fit).

Each pawl of the second pawl device is in particular coupled to the centrifugal mass such that by moving the centrifugal mass out of the rest position, the respective pawl can be actuated. If the pawl returns into the rest position, the pawl is moved back by the centrifugal mass against the spring force of the pawl spring.

In particular, for actuating the pawls of the second pawl device, the actuating pin is fixedly coupled with the centrifugal mass. The rotation points of the pawls and the centrifugal mass are as close to each other as possible or on the same axis, whereby the relative movement upon actuation of the pawls is minimized and thus the wear is minimized.

The preload spring of the centrifugal mass can be formed by an arc spring, a coil spring or a leaf spring, which holds the centrifugal mass in the rest position by means of a defined spring force for decoupling the pawl relative to the pulley or the input shaft. When the limit rotational speed is reached, the centrifugal mass moves outward and the pawl spring closes the generator pawl, i.e. the pawl of the second pawl device.

The limit rotational speed for the actuation of the pawls of the pulley clutch or of the second pawl device can be set in particular by varying the centrifugal mass and/or the preload spring force.

In order to ensure synchronous movement, the centrifugal masses are connected in particular via coupling rings. This ensures simultaneous coupling of the pawls.

In order to minimize wear, oil or grease lubrication of the pawl can be proposed. The pawl may also be coated with a wear resistant material.

The arrangement of the generator pawl (i.e. the pawl of the second pawl device) and the centrifugal force actuating device, i.e. the centrifugal mass, on the first belt pulley makes it possible in particular to achieve a standard air conditioning (opposite to the first rotational direction of the internal combustion engine) which can be operated independently of the rotational speed. The generator pawl is prestressed from the outside inwards by a pawl spring, wherein the spring force is to be greater than the centrifugal force occurring at the pawl. With this arrangement, it is possible to avoid limiting the standard air conditioning to a rotation speed less than the limit rotation speed (e.g., less than the idling rotation speed of the internal combustion engine).

In particular, it is proposed that the air conditioning compressor driven via the fourth pulley can be operated in the negative direction of rotation during standard air conditioning (in contrast to the operation of the air conditioning compressor by the internal combustion engine, which is carried out in the opposite, positive direction of rotation). If this is not possible, the direction of rotation at the air conditioning compressor can be reversed again, for example, by using a rotational direction adjuster known from DE 102017105261 a1, which can be realized, for example, by a planetary gear train having two free wheels at the air conditioning compressor.

It is to be noted preventively that the terms (first, second) used herein above (only) are used to distinguish a plurality of objects, dimensions or processes of the same kind, i.e. that the relevance and/or order of the objects, dimensions or processes is not particularly compulsorily preset. If dependencies and/or sequences are required, this is explicitly stated here or will be obvious to the person skilled in the art when studying the specifically described design.

Drawings

The invention and the technical field are explained in detail below with reference to the drawings. It is to be noted that the invention is not limited by the illustrated embodiments. In particular, unless explicitly indicated otherwise, sub-aspects may also be extracted from the facts set forth in the drawings and combined with other components and knowledge in the present description and/or drawings. It is to be noted in particular that the figures and the particularly illustrated size relationships are merely schematic. The same reference numerals denote the same objects so that the explanations in the other drawings can be used supplementarily as necessary. The figures show:

FIG. 1 shows a side view in cross-section of a torque transmitting device;

FIG. 2 shows a partial perspective view of a cross-section of the torque transmitting device with a pulley clutch according to FIG. 1;

fig. 3 shows a schematic illustration of a first embodiment variant of the pulley clutch in a first switching position;

FIG. 4 shows a schematic illustration of a first embodiment variant of the pulley clutch in a second switching position;

FIG. 5 shows a sectional side view of a second embodiment variant of the pulley clutch in a first switching position;

FIG. 6 shows a side view in section of a second embodiment variant of the pulley clutch in a second switching position;

FIG. 7 shows a sectional side view of a third embodiment variant of the pulley clutch in a first switching position;

FIG. 8 shows a side view in section of a third embodiment variant of the pulley clutch in a second switching position;

fig. 9 shows a schematic illustration of a fourth embodiment variant of the pulley clutch in a first switching position when operating in the first direction of rotation;

FIG. 10 shows a schematic illustration of a fourth embodiment variant of the pulley clutch in a second shift position when operating in the first direction of rotation;

fig. 11 shows a schematic illustration of a fourth embodiment variant of the pulley clutch in a first switching position when operating in the second direction of rotation;

FIG. 12 shows a schematic illustration of a fifth embodiment variant of the pulley clutch in a first switching position when operating in the first direction of rotation;

FIG. 13 shows a schematic view of a fifth embodiment variant of the pulley clutch in a second switching position when operating in the first direction of rotation; and

fig. 14 shows a schematic illustration of a fifth embodiment variant of the pulley clutch in the first switching position when operating in the second direction of rotation.

Detailed Description

Fig. 1 shows a sectional side view of a torque transmission device 21. The torque transmitting device includes: a first pulley arrangement 22 having a first pulley 3 and a second pulley 23, which are connected to each other via a first belt 24; and a second pulley device 25 having a third pulley 26 and a fourth pulley 27 connected to each other via a second belt 28. The first pulley 3 is connected in a switchable manner to the input shaft 2 via a pulley clutch 1, wherein the third pulley 26 is connected in a rotationally fixed manner to the input shaft 2.

In the torque transmission device 21, a decoupling of the input shaft 2 from the second pulley 23 is possible at low rotational speeds 11 in the opposite motor rotational direction (i.e. in the second rotational direction 8) (in particular at rotational speeds 11 below the idling rotational speed of the internal combustion engine 29), which is connected in a rotationally fixed manner to the crankshaft of the internal combustion engine 29.

With the torque transmission device 21, standard air conditioning can be achieved when the internal combustion engine 29 is switched off. The motor 30 is coupled with the two pulleys (the first pulley 3 and the third pulley 26) via the input shaft 2. The first pulley 3 is coupled to a crankshaft pulley (second pulley 23) of an internal combustion engine 29 via a pulley clutch 1 and a first belt 24. Third belt pulley 26 is fixedly connected to a belt starter-generator shaft (input shaft 2; connected in a rotationally fixed manner to the rotor of an electric motor 30) and drives fourth belt pulley 27 via a second belt 28 and thus drives the air conditioning system or the air conditioning compressor.

Fig. 2 shows a partial perspective view of a section through the torque transmission device 21 with the pulley clutch 1 according to fig. 1. First pulley 3 and third pulley 26 are shown, both disposed on input shaft 2. Reference is made to the embodiment of fig. 1.

The first pulley 3 is connected in a switchable manner to the input shaft 2 via a pulley clutch 1, wherein the third pulley 26 is connected in a rotationally fixed manner to the input shaft 2.

It can be seen here that the two

pulleys

3, 26 are in principle mounted and connected to the input shaft 2. The pulley clutch 1 acting on both sides is arranged below a first pulley 3, which is connected to a belt 24 via a second pulley 23 of the crankshaft.

Fig. 3 shows a schematic illustration of a first embodiment variant of the pulley clutch 1 in the first switching position 9. Fig. 4 shows a schematic illustration of a first embodiment variant of the pulley clutch 1 in the second shift position 10.

The pulley clutch 1 comprises an input shaft 2 and a (first) pulley 3 which is connected to the input shaft 2 in a switchable manner via the pulley clutch 1, as well as a first non-actuatable pawl device 4 and a second actuatable pawl device 5. Via the first detent means 4, only the torque 7 of the input shaft 2 can be transmitted to the pulley 3 when there is a first direction of rotation 6 of the pulley 3 and the input shaft 2, wherein the torque 7 of the input shaft 2 cannot be transmitted to the pulley 3 when there is at least a second direction of rotation 8 of the input shaft 2. The second detent means 5 can be actuated between two switching

positions

9, 10. In the first switching position 9, torque 7 cannot be transmitted via the second detent arrangement 5 in both

rotational directions

6, 8. In the second switching position 10, torque 7 can be transmitted from pulley 3 to input shaft 2 only when there is at least a first direction of rotation 6 of pulley 3.

The

detent device

4, 5 comprises a detent 19, via which two rotatable parts (here the first belt pulley 3 and the input shaft 2) can be connected to one another in a rotationally fixed manner (if necessary maintaining a small play). A positive connection between the parts can be produced via the detent 19 and, if necessary, released again. The parts have flanges which are respectively opposite one another and have recesses into which the detent 19 can engage to produce a form fit. The pawl 19 is pivotable so that the form fit is removable. The freewheeling is achieved via the pawls 19 of the

pawl devices

4, 5.

The form fit is dependent here on the direction of

rotation

6, 8 of the components and on which component transmits the torque 7 to the other component.

The first detent means 4 acts in the manner of a free wheel mechanism. Via the first detent means 4, only a torque 7 of the input shaft 2 can be transmitted to the belt pulley 3 when there is a first direction of rotation 6 of the belt pulley 3 and the input shaft 2. The torque 7 present at the belt pulley 3 cannot be transmitted to the input shaft 2 in the first rotational direction 6. In this case, the pulley 3 rotates faster than the input shaft 2. In the presence of at least a second direction of rotation 8 of input shaft 2, torque 7 of input shaft 2 is conversely not transferable to pulley 3. In this case, input shaft 2 rotates faster than pulley 3.

The second detent means 5 is arranged in the first switching position 9 in the non-actuated state (positive fit is not possible) and actuation into the second switching position 10 (positive fit between the two components can occur in relation to the direction of

rotation

6, 8 and the direction of transmission of the torque 7) takes place in relation to the rotational speed 11 of the input shaft 2 or the belt pulley 3.

The pawl 19 of the second pawl device 5 can be moved by the pawl spring 20 from the first switching position 9 into the second switching position 10, the pawl spring 20 being preloaded by the centrifugal mass 12 in the first switching position 9.

The pawl 19 of the first pawl device 4 is also preloaded by the (further) pawl spring 20, so that the pawl 19 can be set in a predetermined position by the pawl spring 20, in which a form fit can be achieved.

If, as shown in fig. 4, the second detent means 5 is also in the form-fitting (second) switching position 10, the torque 7 is transmitted in both

rotational directions

6, 8 and from both components to the respective other component. The electric machine 30 (which is connected to the input shaft 2 in a rotationally fixed manner) can be used for generator operation (i.e. driven by the torque 7 of the internal combustion engine 29; via the first belt pulley 3) or for acceleration operation (i.e. for increasing the torque 7 of the internal combustion engine 29).

Fig. 5 shows a sectional side view of a second embodiment variant of the pulley clutch 1 in the first switching position 9. Fig. 6 shows a sectional side view of a second embodiment variant of the pulley clutch 1 in the second switching position 10. Reference is made to the embodiments of figures 1 to 4. Fig. 5 and 6 are collectively described below.

positions

rotational directions

The pawls 19 of the second pawl device 5 and of the first pawl device 4 and the centrifugal mass 12 of the centrifugal force actuating device 13 are connected to the input shaft 2. When the limit rotational speed is exceeded, the centrifugal mass 12 can be moved out of the rest position 14 (see fig. 5), wherein the second detent device 5 is operable as a result of the movement 15. Centrifugal mass 12 can only move away from rest position 14 against the spring force of preload spring 16. The centrifugal force actuating device 13 has a plurality of (in this case three) centrifugal masses 12 in the circumferential direction 17, which centrifugal masses 12 are coupled to one another via a coupling ring 18, so that the movements 15 of the centrifugal masses 12 take place exclusively in common. The coupling of the centrifugal masses 12 via the coupling ring 18 enables simultaneous actuation of the pawls 19 and compensation of the gravitational force. The pawl 19 of the second pawl device 5 can be moved by the pawl spring 20 from the first switching position 9 into the second switching position 10, the pawl spring 20 being preloaded by the centrifugal mass 12 in the first switching position 9.

The movement of the pawl 19 from the second switching position 10 into the first switching position 9 takes place against the spring force of the pawl spring 20.

Each pawl 19 of second pawl device 5 is coupled to centrifugal mass 12 such that by moving 15 centrifugal mass 12 out of rest position 14, the respective pawl 19 is operable. If the centrifugal mass 12 returns into the rest position 14, the pawl 19 is moved back by the centrifugal mass 12 against the spring force of the pawl spring 20. An actuating pin 31 for actuating the pawls 19 of the second pawl device 5 is fixedly coupled to the centrifugal mass 12. The rotational axes 32 (rotational points) of the pawls 19 and of the centrifugal mass 12 are as close to one another as possible or, as shown here, lie on the same axis, whereby the relative movement and thus the wear on the actuation of the pawls is minimized.

The preload spring 16 of the centrifugal mass 12 is formed by an arc spring (see fig. 5 and 6), a helical spring or a leaf spring (see fig. 7 and 8), which holds the centrifugal mass 12 in the rest position 14 by means of a defined spring force for decoupling the pawl 19 relative to the pulley 3 or the input shaft 2. When the limit rotational speed is reached, the centrifugal masses 12 move outwards and the pawl springs 20 close the generator pawls, i.e. the pawls 19 of the second pawl device 5.

The pawl 19 is prestressed outwards by a pawl spring 20 and is also deactivated or decoupled by the centrifugal force actuating device 13.

The second variant of embodiment of the pulley clutch 1 is designed with an arc spring as the preload spring 16. The first switching position represents the pawl position shown in fig. 5 when the internal combustion engine 29 is switched off or at a low rotational speed 11 at the pulley 3 (for example less than 700 revolutions per minute). It can be seen here that the pawl 19 (starting pawl) of the first pawl device 4 engages in the motor running direction (first rotational direction 6) and rolls over in the opposite running direction (second rotational direction). The generator pawl (pawl 19 of the second pawl device 5) connected in parallel thereto is disengaged by the centrifugal force actuating device 13 by means of the preload spring 16 in the rest state and at low rotational speeds 11. The limit speed of the pulley clutch 1 can be set in relation to the preload spring force and the centrifugal mass size.

Fig. 6 shows the state during the operation of the electric motor, in which the generator pawl (i.e. the pawl 19 of the second pawl device 5) is engaged. This takes place without impact, since the starting pawl (pawl of the first pawl device) is in the line of force during actuation (motor start, etc.) and the generator pawl can be freely engaged.

The stop for the centrifugal mass 12 can furthermore be the fixedly coupled pulley 3 itself.

Fig. 7 shows a sectional side view of a third embodiment variant of the pulley clutch 1 in the first switching position 9. Fig. 8 shows a sectional side view of a third embodiment variant of the pulley clutch 1 in the second switching position 10. Fig. 7 and 8 are collectively described below. Reference is made to the embodiments of fig. 5 and 6.

Here, the preload spring 16 is realized in the centrifugal mass 12 by a spring or leaf spring. The advantage here is that a smaller space requirement and thus a higher space utilization of the centrifugal mass 12 is possible. The frictional contact between the leaf spring and the pulley 3 can lead to wear during the relative movement, whereby the path is minimized or a friction partner having a friction coefficient as low as possible should be selected. In addition, lubricants can also be used here to minimize wear.

Fig. 9 shows a schematic illustration of a fourth embodiment variant of the pulley clutch 1 in the first switching position 9 when operating in the first direction of rotation 6. Fig. 10 shows a schematic illustration of a fourth embodiment variant of the pulley clutch 1 in the second shift position 10 when operating in the first rotational direction 6. Fig. 11 shows a schematic illustration of a fourth embodiment variant of the pulley clutch 1 in the first switching position 9 when operating in the second direction of rotation 8. Reference is made to the embodiments of figures 1 to 9. Fig. 9 to 11 are collectively described hereinafter.

In the fourth variant embodiment, the pulley clutch 1 is formed by two

parallel pawl devices

4, 5 which act in such a way that a torque 7 is transmitted in opposite directions of

rotation

6, 8. The generator pawl (pawl 19 of the second pawl device 5) is connected to the centrifugal force actuating device 13. The main difference lies in the connection of the generator pawl, which no longer has its axis of rotation 32 in the input shaft 2, but now has its axis of rotation 32 in the first pulley 3 (which is connected to the crankshaft of the internal combustion engine 29). Centrifugal mass 12 can thus likewise be fixed to pulley 3, so that centrifugal forces act on centrifugal mass 12 only when pulley 3 is rotating. The generator pawl is therefore engaged only after the internal combustion engine 29 has started. When the electric motor 30 is rotated back in the normal air-conditioning mode (second direction of rotation 8), the pawl 19 of the second pawl device 5 remains decoupled at all times. The starting pawl of the first pawl device 4 is furthermore arranged on the input shaft 2.

The forces acting here should act in the following order: the centrifugal force of the pawls 19 is smaller than the spring force of the pawl springs 20 of the second pawl means 5 is smaller than the spring force of the preload springs 16 is smaller than the centrifugal force of the centrifugal force operating means 13.

Fig. 12 shows a schematic illustration of a fifth embodiment variant of the pulley clutch 1 in the first switching position 9 when operating in the first direction of rotation 6. Fig. 13 shows a schematic illustration of a fifth embodiment variant of the pulley clutch 1 in the second shift position 10 when operating in the first rotational direction 6. Fig. 14 shows a schematic illustration of a fifth embodiment variant of the pulley clutch 1 in the first switching position 9 when operating in the second direction of rotation 8. Reference is made to the embodiments of fig. 9 to 11. Fig. 12 to 14 are collectively described hereinafter.

In the fifth variant embodiment, two pawl devices 4, 5 (generator and starter pawl) are connected to the pulley 3 (of the crankshaft). This has the advantage that standard air conditioning is furthermore independent of the rotational speed and can additionally advantageously form a rolling movement of the starting pawl (pawl 19 of the first pawl device) in the freewheeling direction. The detent spring force of the two detents 19 must at least compensate for the centrifugal force of the detent 19 in order to ensure a reliable second switching position 10.

The forces acting here should therefore act in the following order: the centrifugal force of the pawls 19 is smaller than the spring force of the pawl springs 20 of the first and

second pawl devices

4, 5 than the spring force of the preload spring 16 is smaller than the centrifugal force of the centrifugal force operating device 13.

Description of the reference numerals

Pulley clutch 2 input shaft 3 (first) pulley 4 first pawl means 5 second pawl means 6 first direction of rotation 7 torque 8 second direction of rotation 9 second switching position 10 second switching position 11 rotational speed 12 centrifugal mass 13 centrifugal force operator 14 rest position 15 movement 16 preload spring 17 circumferential 18 coupling ring 19 pawl spring 21 torque transfer means 22 first pulley means 23 first belt 25 second pulley means 26 third pulley 27 fourth pulley 28 second belt 29 internal combustion engine 30 motor 31 actuating pin 32 axis of rotation.

Claims

1. A pulley clutch (1) having at least an input shaft (2) and a pulley (3) which is connected to the input shaft (2) in a switchable manner via the pulley clutch (1), and a first non-actuatable pawl device (4) and a second actuatable pawl device (5), wherein only a torque (7) of the input shaft (2) can be transmitted to the pulley (3) via the first pawl device (4) in a first direction of rotation (6) of the pulley (3) and the input shaft (2), wherein the torque (7) of the input shaft (2) cannot be transmitted to the pulley (3) in at least a second direction of rotation (8) of the input shaft (2), wherein the second pawl device (5) can be actuated between two shift positions (9, 10), wherein in the first shift position (9) in both directions of rotation (6), 8) is not transferable via the second detent means (5), wherein in the second switching position (10) the torque (7) is transferable from the pulley (3) to the input shaft (2) only in at least the first direction of rotation (6) of the pulley (3).

2. Pulley clutch (1) according to claim 1, wherein said second pawl means (5) are operable according to a rotation speed (11).

3. Pulley clutch (1) according to claim 2, wherein the second pawl device (5) is arranged in the first switching position (9) in the non-actuated state and the actuation into the second switching position (10) is effected in relation to the rotational speed (11) of the input shaft (2) or of the pulley (3).

4. Pulley clutch (1) according to claim 3, wherein the centrifugal mass (12) of the centrifugal force actuating device (13) can be moved out of a rest position (14) in the event of exceeding a limit rotational speed, wherein the second pawl device (5) is actuated as a result of the movement (15).

5. Pulley clutch (1) according to claim 4, wherein the centrifugal mass (12) can only be moved out of the rest position (14) against the spring force of a preload spring (16).

6. Pulley clutch (1) according to one of the preceding claims, wherein the centrifugal force manipulation device (13) has a plurality of centrifugal masses (12) in a circumferential direction (17), which are coupled to one another via a coupling ring (18) such that the movements (15) of the centrifugal masses (12) take place exclusively in common.

7. Pulley clutch (1) according to one of the preceding claims 4 to 6, wherein the pawl (19) of the second pawl device (5) is moved by a pawl spring (20) from the first switching position (9) into the second switching position (10), wherein the pawl spring (20) is pretensioned by the centrifugal mass (12) in the first switching position (9).

8. Pulley clutch (1) according to claim 7, wherein the pawl (19) and the centrifugal mass (12) are connected with the input shaft (2).

9. Pulley clutch (1) according to claim 7, wherein said pawls (19) and said centrifugal mass (12) are connected with said pulley (3).

10. A torque transmitting device (21) comprising at least: a first pulley arrangement (22) having at least one first pulley (3) and a second pulley (23) which are connected to each other via a first belt (24); and a second pulley arrangement (25) having at least one third pulley (26) and a fourth pulley (27) which are connected to one another via a second belt (28), wherein the first pulley (3) is switchably connectable to the input shaft (2) via a pulley clutch (1) according to one of the preceding claims, wherein the third pulley (26) is connected in a rotationally fixed manner to the input shaft (2).