Switchable freewheel with a friction clutch

Abstract

A switchable freewheel (1) has a clutch (22) which is a friction clutch (15).

Description

[0001] DE 10 2010 031 508 B4 discloses a transmission device in which a shaft of a shaft module is mounted in a housing by means of a plain bearing. The wheel-shaped drive element is designed as a gear. A freewheel is arranged radially between the gear and the shaft. The gear has a gear hub with which it is mounted radially on the hub by means of a plain bearing and on which the clamping bodies run radially outward. A freewheel ring surrounds the ring of clamping bodies radially outward and is rigidly connected to the shaft. The clamping bodies are arranged radially outward in the outer freewheel ring and radially between the outer freewheel ring and the gear hub. In this arrangement, the freewheel is functionally connected between the drive element and the shaft.

[0002] US Pat. No. 7,604,105 B2 discloses an electromagnetically actuated freewheel whose clutch is provided with an elastic clutch disc. The clutch disc is arranged concentrically to a shaft on which the clamping structure of the freewheel is also formed. The elastic disc is in positive engagement with a bridge, which in turn is in positive engagement with the cage of the freewheel, thus establishing a permanent positive connection between the clutch disc and the cage. The bridge is suspended axially in the clutch disc in a form-fitting manner by an amount by which the disc, which is provided with a ferromagnetic or magnetizable zone, moves against the magnetic coil when the electromagnetic actuating device is energized.By energizing the electromagnetic actuator, the clutch disc is pulled axially against the coil, where it rests against the coil via a rotary bearing, supporting it against rotation. The bridge also temporarily prevents the freewheel cage from rotating, and the freewheel is engaged.

[0003] Further freewheels are known from DE 11 2019 001 588 T5 and WO 2016 / 165 712 A1. Description of the invention

[0004] The object of the invention is to create a switchable freewheel which is simple in design, capable of transmitting high torques and which can be manufactured cost-effectively.

[0005] The problem is solved according to the subject matter of claim 1.

[0006] The invention provides that the clutch is a friction clutch, with which a frictionally engaged operative connection between the cage and the second track, which is rotationally fixed about the rotation axis, can be repeatedly engaged and disengaged. The advantage of using such a clutch lies in particular in the fact that the relative movements / rotations between the cage and a clamping structure of the freewheel can be braked smoothly and without sudden stoppage. In this way, a controlled synchronization process can be carried out to align the relative movements. The components of the freewheel, in particular the cage, are protected against overloads. Furthermore, the controlled braking can prevent unwanted slippage between the actuating device and the cage.

[0007] The clutch disc is arranged concentrically to the axis of rotation and at least pivotable relative to the tracks, i.e. pivotable and / or rotatable in either circumferential direction around the axis of rotation.

[0008] The clutch disc is connected to the cage in the circumferential direction around the axis of rotation in a form-locking connection such that the clutch disc is axially displaceable relative to the cage within an axially limited axial stroke, but is nevertheless permanently connected to the cage in a form-locking manner around the axis of rotation at any axial position within the axial stroke. An example of such a form-locking connection is a plug-in connection, within which the clutch disc and the cage remain axially movable relative to one another without losing the form-locking connection for torque transmission. In this case, the torques to be transmitted are understood to be the control torques necessary to stop or pivot the rotating cage and thus the inertia forces and drag torques of the clamping bodies acting on the cage.The plug connection does not have to be formed directly between the clutch disc and the cage, but can be formed via a bridge designed as a separate component, via which the cage and the clutch disc are connected to each other.

[0009] A further feature of the invention is that the ferromagnetic zone of the clutch disc and the actuating device lie opposite one another without contact, even when the magnetic field of the actuating device is switched on, meaning that there is no direct contact between the actuating device and the clutch disc in any of the operating states. Ferromagnetic or magnetizable zones are zones on the clutch disc that are suitable for being axially attracted and / or repelled by the actuating device within the stroke under the influence of a magnetic field generated by the actuating device. Direct contact between the clutch disc and the actuating device, as known from the prior art described above, is therefore deliberately avoided. This advantageously makes it possible, for example, to dispense with a rotary bearing arranged between the actuating device and the clutch disc.A zone can, for example, be designed as a ring or a hollow cylinder. Multiple zones are described, for example, by adjacent zones distributed around the circumference of the rotation axis.

[0010] The freewheel has a number of inner tracks corresponding to the number of rows of clamping bodies. In addition, a number of outer tracks is provided corresponding to the number of rows of clamping bodies. Either the inner track or the outer track of a freewheel is provided with a clamping structure which preferably has clamping ramps. The track radially opposite the track with the clamping structure at a radial gap is then a raceway which is preferably cylindrical. The clamping bodies are arranged in a row in the circumferential direction around the axis of rotation of the freewheel and radially between the inner track and the outer track. In the freewheel, each clamping body has a clamping ramp and, depending on the operating state, one of the sections of the raceway is radially opposite each other.The raceway is formed either on the inner track or on the outer track and is either an inner-cylindrical or outer-cylindrical track. An outer raceway or an inner raceway is radially opposite the inner track or outer track of the freewheel, on which the clamping structure is formed.

[0011] The freewheel can optionally have one or more rows of sprags. A row is defined by a defined number of sprags which are arranged one after the other in the circumferential direction around the axis of rotation of the freewheel and are therefore adjacent to one another in the circumferential direction. If there is more than one row, one row is arranged adjacent to the other. In these cases, the sprags of both rows either lie opposite one another on a common raceway, or each row is assigned a separate raceway. A common raceway then has an axial width whose effect covers the sprags of both rows. If the raceways are separate, they are axially adjacent to one another. In addition, the clamping ramps can either be designed to axially effectively cover both rows, and the individual clamping ramps can be arranged one after the other in the circumferential direction to together form a clamping structure.Alternatively, each of the multiple rows is assigned a clamping structure, each of which is formed from a plurality of clamping ramps arranged consecutively in the circumferential direction and which is axially adjacent to at least one other clamping structure. "Consecutive" always means that these clamping ramps either directly follow one another in the circumferential direction, or in individual cases or always between two adjacent clamping ramps, other elements such as brackets, grooves, etc. can be formed.

[0012] The inner track, the outer track, the clutch disc, and the cage are arranged concentrically with each other and with the rotational axis as a common central axis. The rotational axis of the freewheel is the rotational axis for rotating components of the freewheel and is defined as axially aligned, regardless of their actual position in space. Accordingly, radial alignment is perpendicular and transverse to the rotational axis.

[0013] The clamping bodies are held in position in the cage, pivotable and guided.

[0014] The fact that the clutch disc is arranged concentrically to the axis of rotation and at least pivotably relative to the tracks means that the clutch disc is mounted rotatably about the axis of rotation at least to both or alternatively to one of the tracks.

[0015] One embodiment of the invention provides that the friction clutch has at least one friction ring, wherein the friction ring is connected to the second track so as to be rotationally fixed about the axis of rotation. The second track is preferably an inner-cylindrical or outer-cylindrical raceway for the clamping bodies. In addition, the friction ring is provided with at least one first friction surface. The clutch disc has at least one second friction surface. The friction ring and the clutch discs can optionally be multi-disk discs with circular and flat friction surfaces that correspond with one another in frictional engagement. Alternatively, the friction surfaces are designed with an internal and / or external conical shape. The first friction surface and the second friction surface can be engaged axially movably into the frictionally engaged operative connection within the axial stroke. Engagement means establishing the frictional connection with or without slippage between the clutch disc and the friction ring.Disengagement means breaking the frictional connection. The advantage of this embodiment of the invention is that such friction rings and friction surfaces can be manufactured easily and cost-effectively, both for wet applications (under the influence of lubricants) with preferably metallic friction surfaces, and for dry applications, e.g., with friction linings, both in mass production and in small batches.

[0016] One embodiment of the invention provides that the zone and the actuating device are spaced apart from each other without contact by a distance that is greater than the axial stroke. This ensures that the actuating device and the clutch disc remain spaced apart without contact, even when the maximum stroke is utilized.

[0017] A further embodiment of the invention provides that the positive connection is formed by at least two positive locking elements. A first positive locking element is optionally formed either on the cage and / or on the clutch disc, which forms at least one axially extending first extension with a polygonal or rounded cross-section. The extension engages in a first gap of a second positive locking element that is rotationally fixedly assigned to either the clutch disc and / or the cage. Examples of such positive locking connections are those in the manner of a fork joint connection or interlocking claws and plug-in connections. The gaps are formed, for example, on forks, in profiles such as U-shaped or open or closed box profiles. Such connections can be manufactured simply and cost-effectively using sheet metal construction or as plastic injection-molded, pressed or cast parts.

[0018] One embodiment of the invention provides that an elastic stop is arranged or clamped axially between the friction ring and the clutch disc, wherein the clutch disc is axially elastically preloaded against the elastic stop, at least in the engaged frictional connection. According to one embodiment, the stop is therefore initially arranged axially between the friction ring and the clutch disc without being preloaded and is then clamped between the friction ring and the clutch disc by the clutch disc moved by a magnetic field. An alternative embodiment provides that the elastic stop is permanently clamped between the clutch disc and the friction ring, wherein its preload increases with increasing stroke of the clutch disc in the direction of the actuating device. Such an arrangement ensures that the frictional connection is reliably separated again when the clutch is disengaged.

[0019] One embodiment of the invention provides that the clutch disc is supported on a first shaft so as to be radially rotatable about the axis of rotation and axially displaceable, wherein the second track, i.e. the track designed as a cylindrical raceway, is connected to this first shaft so as to be rotationally fixed about the axis of rotation. The term shaft covers any components that are rotationally mounted or supported and / or that are suitable for transmitting torque. The first shaft is rotationally fixedly connected to the clamping structure. Rotationally fixed means that they are either formed as one piece or, for example, on a ring pressed onto or into the shaft. One embodiment provides that the first shaft is a gearwheel into whose inner cylindrical receptacle a sheet metal sleeve is pressed, on which the clamping ramps are formed.Another development provides for the second shaft to be formed integrally with an externally cylindrical raceway of the freewheel. Arrangements of this type make it possible to design a self-supporting assembly from all the elements of the freewheel. This can save effort and costs during assembly. This is particularly true if, as one embodiment of the invention provides, the first shaft is connected in a rotationally fixed manner, for example via a serration or wedge toothing or a keyway, to a third shaft on which the second shaft is rotatably mounted. The second shaft is preferably a stub shaft with the raceway of the freewheel. The first shaft is, for example, a gearwheel which internally accommodates the freewheel and which is mounted on the third shaft designed as a gear shaft. The gear shaft is optionally mounted on or at another gear shaft or in a gear housing.

[0020] According to a further development of the aforementioned embodiment, the clutch disc is preferably mounted radially and axially on the first shaft using a radial needle bearing. This means that the radial needle bearing, which is actually only intended for radial bearing support, is given a new application according to the invention, namely that in a type of axial plain bearing, through which the axial displaceability of the clutch disc within the axial stroke is designed with low friction. The radial load share of the needle bearing is low, since it only has to support the clutch disc radially and rotationally without any appreciable load. The friction between the needles and the first shaft occurs in the line contact between the needles of the needle bearing and a cylindrical raceway (formed in one piece or on a sleeve) on the first shaft, so that this can also be kept low due to the low radial loads.The advantage of this design is that such a needle bearing for the clutch disc can be implemented cost-effectively using needle bearings that are mass-produced for all possible applications and are already available from the catalog. Description of the drawings

[0021] The invention is explained in more detail below using an exemplary embodiment. Fig. 1 shows a shaft module 50 with a switchable freewheel 1 in a longitudinal section along its rotation axis 12. Fig. 2 shows a section A from the illustration according to Fig. 1, in which the clutch 22 of the freewheel 1 is axially engaged. Fig. 3 shows section A of the illustration according to Fig. 1, in which the clutch of the freewheel 1 is axially disengaged. Fig. 4 shows a section of the cross-section of the freewheel 1 which is switched to block in one direction of rotation. Fig. 5 shows the section after Fig. 4, in which, however, the freewheel 1 is shown locked in a different direction of rotation. Fig. 6 shows the released freewheel 1 in the section according to Fig. 4. Fig. 7 shows a perspective view of the freewheel 1, opposite which the clutch disc 6 is shown axially spaced in the manner of an exploded view. Fig. 8 shows a further embodiment of a shaft module 60 in a longitudinal section along its rotation axis 12. Fig. 9 shows a section of the cross section of the released freewheel 61 of the shaft module 60. Fig. 10 shows a section of the cross section of the freewheel 61 of the shaft module 60, which is switched to block in one direction of rotation.

[0022] Fig. 1 - The freewheel 1 is designed as a two-row assembly and has two axially adjacent first tracks 2 with identical profiles, and two axially adjacent second tracks 3 with identical profiles. Each of the first tracks 2 is located opposite one of the second tracks 3 across a radial gap 9 running around the rotation axis 12. Two rows 32 and 33 of cylindrical clamping bodies 4 are arranged radially in the radial gap 9 between a first track 2 and a second track 3, respectively, and are received in a cage 5. Each first track 2 is provided with a clamping structure 10, wherein in this case the clamping structure 10 is formed as a single piece and axially overlaps both first tracks 2. Each second track 3 is provided with an externally cylindrical raceway 37 for the clamping bodies 4, wherein in this case the raceway 37 is formed as a single piece and axially overlaps both second tracks 3.

[0023] The switchable freewheel 1 is further provided with an electromagnetic actuating device 8 and a clutch 22. The clutch 22 has a clutch disc 6, which is arranged concentrically to the rotational axis 12 and is provided with at least one ferromagnetic or magnetizable annular disc-shaped zone 55. The zone 55 is formed in the material of the clutch disc 6 and is symbolically marked with the vertical line that appears thick in the image. The clutch disc 6 is optionally made of a ferromagnetic metal or plastic. In the latter case, the plastic in the zone is permeated with magnetizable or magnetized material. Alternatively, the zone 55 is inserted into the clutch disc 6 and fastened to the disc. The electromagnetic actuating device 8 is provided with an energizable magnetic coil 34 and a housing 35.The magnetic coil 34 and the zone 55 are arranged opposite each other such that the zone 55 lies in a magnetic field of the energized magnetic coil 34.

[0024] The shaft module 50 is formed from the freewheel 1, a gear 51, a third shaft 31, and tapered roller bearings 41 and 42. The first shaft 28 of the freewheel 1 represents a freewheel hub, which is integrally formed with the second tracks 3, i.e., is rotationally fixedly connected to the outer cylindrical raceway(s) 37, rotatable about the rotation axis 12. A second shaft 30 of the freewheel is rotatably mounted on the third shaft 31 by means of a plain bearing 43. The second shaft 30 is simultaneously designed as a gear 51 of the shaft module 50 and as a housing for a freewheel ring 44. The first shaft 28 is rotationally fixedly connected to the third shaft 31 via a spline 38. The third shaft 31 is provided with the spline 38, a bearing seat 39 for the plain bearing 43 and a toothing 40 of a gear 52 formed integrally with the third shaft 31 and is equipped with the tapered roller bearings 41 and 42.

[0025] The first shaft 28 and the third shaft 31, as well as the gear 52 formed on the third shaft 31, are connected and therefore jointly rotatable about the rotation axis 12. The second shaft 30 with the clamping structure 10 and the gear 51 are jointly formed and, when the clutch 22 is disengaged, are mounted on the third shaft 32 with the plain bearing 43 so as to be rotatable about the rotation axis 12 relative to the first shaft 28. Via the clutch 22, a frictionally engaged operative connection, rotationally fixed about the rotation axis 12, between the cage 5 and the second track 3 can be repeatedly engaged and disengaged by axial displacement of the clutch disc 6 within an axially limited axial stroke.

[0026] Fig. 2 - The clutch 22 is a friction clutch 15. The friction clutch 15 has a friction ring 20. The friction ring 20 is connected to the second track 3 in a rotationally fixed manner about the rotation axis 12 and is provided with at least one first friction surface 19 with an internal cone. The clutch disc 6 has a second friction surface 21 with an external cone. The second friction surface 21 is coupled to the cage 5 via the clutch disc 6. The clutch disc 6 is radially supported and axially displaceably mounted on the first shaft 28 by means of a radial needle bearing 29. The interface at which the clutch disc 6 is displaceable relative to the first shaft 28 is formed by line contacts between the needles 48 of the radial needle bearing 29 and the bearing raceway 49 on the first shaft 28.

[0027] In the illustration according to Fig. 2, the clutch plate 6 is in an end position, which was assumed by a displacement of the clutch plate 6 to the right in the image, so that the clutch 22 is disengaged. The first shaft 28 and the third shaft 32 as well as the gear 52 formed on the third shaft 32 (only partially visible in this illustration, but see Fig. 1) are connected and therefore mounted jointly for rotation about the rotation axis 12. The second shaft 30 with the clamping structure 10 and the gear 51 are jointly formed or connected to one another and, in the disengaged state of the clutch 22, are rotatable about the rotation axis 12 relative to the first shaft 28.

[0028] In the disengaged state, the clutch disc 6 is in a position in which the distance of the clutch disc 6 or from its end face 36 from each contour of the actuating device 8 that projects axially furthest from the end face 54 of the actuating device 8 is composed of the stroke H and the safety distance A. The second friction surface 21 of the clutch disc 6 is separated from the first friction surface 19 of the friction ring 20 upon disengagement. The clutch disc 6 is in a positive connection 18 with the cage 5 such that a torque-resistant connection is formed between the cage 5 and the clutch disc 6 in the circumferential direction around the rotation axis 12 even in this operating state - iethat the clutch disc 6, which is axially displaceable relative to the cage 5 within the axially limited axial stroke H, is rotationally fixed about the rotation axis 12 and is / remains permanently positively connected to the cage 5 even when the clutch disc 6 is displaced by the full stroke H away from the cage 5 in the direction of the friction ring 20.

[0029] Fig. 3 - The second friction surface 21 of the clutch disc 6 is in a frictional connection with the first friction surface 19 of the friction ring 20, ie the clutch 22 is engaged. The dimension H is zero. The distance between the clutch disc 6 and each contour of the actuating device 8 which projects axially in the direction of the end face 36 corresponds to the safety distance A. The end face 36 of the clutch disc 6 opposite the actuating device 8 is arranged away from each contour of the actuating device 8 which projects axially the furthest in the direction of the end face 36 by the safety distance A, the smallest value of which is always greater than the value zero, so that the clutch disc 6 and in particular the zone 55 lie opposite one another without contact in every operating state, even when the magnetic field of the magnetic coil 34 of the actuating device 8 is switched on.

[0030] In the engaged state, there is an operative connection between the clamping bodies 4 via the cage 5, from the cage 5 via the positive connection 18 to the clutch disc 6, from there via the two frictionally engaged friction surfaces 19 and 21 to the friction ring 20 of the first shaft 28, from the friction ring 20 to the second track 3 integrated into the first shaft 28, i.e. to the raceway 37. The freewheel 1 is locked, so that in the freewheel 1, a clamping connection is formed between the first shaft 28 and the second shaft 30 via the clamping bodies 4. The three shafts 28, 30 and 31 rotate together.

[0031] The freewheel ring 44 has the first tracks 2, i.e., those with a clamping structure 10. The freewheel ring 44 is a cold-formed sheet metal component with a cylindrical sleeve 45 and a rim 46 extending radially inward from the sleeve 45 in the direction of the rotation axis 12. The cylindrical sleeve 45 is pressed firmly into an inner cylindrical hole 47 of the second shaft 30.

[0032] Fig. 4 - The clamping structure 10 formed on the first track 2 is formed by individual clamping ramps 11 running tangentially to the circumferential direction, which are formed in a row one behind the other around the rotational axis 12 (not visible in this section) of the freewheel 1 on the inside of the sleeve 45. The outer-cylindrical second track 3 for the clamping bodies 4 lies radially opposite the first track 2 at the radial gap 9. The clamping bodies 4 are clamped between the tracks 2 and 3 because the clamping bodies 4 have run onto the clamping ramps 11, which in the figure are arranged in the counterclockwise direction of rotation, due to the pivoting of the cage 5 at the positive connection 18. The operating state shown corresponds to a Fig. 3, in which the clutch 22 is engaged.

[0033] Fig. 5 - The clamping bodies 4 are clamped between the tracks 2 and 3 because the clamping bodies 4 have run onto the clamping ramps 11 due to the pivoting of the cage 5. The operating state shown corresponds to a Fig. 3, in which the clutch 22 is engaged. In this case, however, the clamping bodies 4 are, compared to their Fig. 4 shown position, on clamping ramps 11, which are in clockwise direction of rotation.

[0034] Fig. 6 - An operating condition is shown that corresponds to Fig. 2—that is, the position with the clutch 22 disengaged. The clamping bodies 4 are each positioned in a gap 53 formed between two adjacent clamping ramps 11 and are therefore no longer clamped. The raceways 2 and 3 can rotate freely and independently of each other.

[0035] Fig. 7 - The positive connection 18 is formed by at least two positive locking elements 13 and 14. The respective first positive locking element 13 is formed on the cage 5 and designed as an axial extension 23. In the illustration, the respective extension 23 is opposite a gap 25 on the clutch disc 6, which is each delimited by second positive locking elements 14 or forms the second positive locking elements 14. Viewed from the other direction, axial extensions 24 are alternatively formed on the clutch disc 6, each of which is opposite a gap 26 between two extensions 23 of the cage 5. In the assembled state, one extension 23 or 24 engages in a gap 25 or 26.

[0036] Fig. 8, Fig. 9 and Fig. 10 - The design of the shaft module 60 is essentially comparable to that of the previously described shaft module 50. However, it differs in some specific features described below. The operation of the freewheels 1 and 61 is fundamentally the same, so the above description can also be applied to the shaft module 60, subject to the design deviation described below.

[0037] Fig. 8 - Unlike freewheel 1, freewheel 61 is single-row, i.e., it is designed with a row of sprags 64. The sprags 64 are housed in a cage 65. The first track 2 is provided with a clamping structure 10 on the sleeve 45. The second track 3 is provided with an externally cylindrical raceway 37 for the sprags 64.

[0038] The switchable freewheel 61 is further provided with the above-described electromagnetic actuating device 8 and a clutch 22. The structure and mode of operation of the clutch 22 and the actuating device 8 are the same for both freewheels 1 and 61.

[0039] The shaft module 60 is formed from the freewheel 61, the gear 51, and the third shaft 31. The first shaft 28 of the freewheel 61 represents a freewheel hub, which is integrally formed with the second track 3, i.e., is rotationally fixedly connected to the outer cylindrical raceway 37 so as to be rotatable about the rotation axis 12. In contrast to the design of the shaft module 50, a second shaft 30 of the freewheel 61 is rotatably mounted on the third shaft 31 by means of a needle roller and cage 57, which is formed from needle roller and cage 65 of the needle roller and cage 57 and from needles 59 guided in the cage 65. The second shaft 30 is simultaneously designed as the gear 51 of the shaft module 60 and as a housing for the freewheel ring 44. The first shaft 28 is rotationally fixedly connected to the third shaft 31 via the spline 38.The third shaft 31 is provided with a portion of the spline 38, a bearing raceway 66 for the needle roller and cage 57 and with a toothing 40 of a gear 52 formed integrally with the third shaft 31.

[0040] The first shaft 28 and the third shaft 31, as well as the gear 52 formed on the third shaft 31, are connected and therefore jointly rotatable about the rotational axis 12. The second shaft 30 with the clamping structure 10 and the gear 51 are jointly formed and, when the clutch 22 is disengaged, are mounted on the third shaft 32 with the needle bearing 57 so that they can rotate about the rotational axis 12 relative to the first shaft 28. Via the clutch 22, a frictionally engaged, rotationally fixed, operative connection between the cage 65 and the second track 3 can be repeatedly engaged and disengaged by axial displacement of the clutch disc 6 within an axially limited axial stroke. The friction ring 67 differs from the friction ring 20 of the freewheel 1 in that it is formed in two parts and assembled, with the friction surface 19 being formed on a conical ring 68 made of sheet metal and attached to the freewheel hub.An elastic stop 27, which in this case is designed as a corrugated or disc spring, is clamped between the friction ring 67 and the end face of the clutch disc 6, at least when the clutch 22 is maximally engaged, in such a way that the friction surfaces 19 and 21 are completely separated from one another.

[0041] Fig. 9 - The positive connection 62, with which the cage 65 and the clutch disc 67, symbolized in this illustration only via the positive locking elements 13 or extensions 23, are positively connected, differs from the above-described positive connection 18 in the freewheel 1. The respective first positive locking element 13 is optionally formed on the cage 65 or the clutch disc 6 and designed as an axial extension 23. Each extension 23 is inserted into a hollow profile 63, designed as an open box profile, of a second positive locking element 14. The positive locking element 14 is formed either on the cage 65 or on the clutch disc 6 or is arranged as a bridge element between the cage 65 and the clutch disc 6. An operating state is shown which is analogous to that with Fig. 2—that is, to the position when the clutch 22 is disengaged. The clamping bodies 64 are each positioned in a gap 53 formed between two adjacent clamping ramps 11 and are therefore no longer clamped. Tracks 2 and 3 run freely and independently of each other.

[0042] Fig. 10 - The clamping bodies 64 are clamped between the tracks 2 and 3 because the clamping bodies 64 have run onto the clamping ramps 11, which are shown in the counterclockwise direction of rotation in the figure, due to the pivoting of the cage 65 at the positive connection 62. The operating state shown is analogous to a Fig. 3 is to be regarded as one with the clutch 22 engaged. Reference symbol 1 switchable freewheel 2 first lane 3 second lane 4 clamping bodies 5 cage 6 clutch disc 7 Friction device 8 Actuating device 9 Radial gap 10 Clamping structure 11 clamping ramps 12 Rotation axis 13 Form-locking element 14 Form-locking element 15 Friction clutch 16 housings 17 Zone 18 Form-fitting connection 19 first friction surface 20 friction ring 21 second friction surface 22 Clutch 23 first extension 24 second extension 25 first gap 26 second gap 27 elastic stop 28 first wave 29 radial needle bearings 30 second wave 31 third wave 32 first row of clamping bodies 33 second row of clamping bodies 34 Solenoid coil of the actuating device 35 Housing of the actuating device 36 Front side of the clutch disc 37 Career 38 spline 39 bearing seat 40 gearing 41 tapered roller bearings 42 tapered roller bearings 43 plain bearings 44 Freewheel ring 45 sleeve 46 Board 47 internal cylindrical hole 48 needles of the radial needle bearing 49 Bearing raceway for the radial needle bearing 50 wave module 51 Gear of the shaft module 52 Gear of the third shaft 53 gaps 54 Front side of the actuating device 55 Zone 56 Wave spring or disc spring 57 needle wreath 58 Cage of the needle roller and cage 59 needles of the needle wreath 60 wave module 61 Freewheel 62 Form-fitting connection 63 hollow profile 64 clamping bodies 65 cage 66 warehouse career 67 Friction ring 68 cone ring A safety distance H axial stroke

Claims

[1] Switchable freewheel (1, 61) comprising at least one first track (2) and at least one second track (3), several clamping bodies (4, 64), at least one cage (5, 65), an electromagnetic actuating device (8) and a clutch (22), wherein - the first track (2) and the second track (3) are radially opposite each other at a radial gap (9) extending around a rotation axis (12), - the first track (2) is provided with at least one clamping structure (10), wherein in the clamping structure (10) individual clamping ramps (11) are formed in a row around a rotation axis (12) of the freewheel (1, 61) in succession, - the second track (3) is provided with a track (37) for the clamping bodies (4, 64) and is rotatable about the rotation axis (12) relative to the first track (2), - the clamping bodies (4, 64) are arranged radially between the tracks (2, 3) in the radial gap (9) and are accommodated in the cage (5, 65), - the clutch (22) has at least one clutch disc (6) which is arranged concentrically to the axis of rotation (12) and is provided with at least one ferromagnetic or magnetizable zone (55), - the zone (55) is opposite a magnetic field of the actuating device (8) which can be switched on and off, characterized by that the clutch (22) is a friction clutch (15), wherein - a frictionally engaged connection between the cage (5, 65) and the second track (3) which is rotationally fixed about the rotation axis (12) can be repeatedly engaged and disengaged via the friction clutch (15), - the clutch disc (6) is arranged to be axially displaceable relative to the tracks (2, 3), - the clutch disc (6) is in a form-fitting connection (18, 62) with the cage (5, 65) in the circumferential direction around the rotation axis (12) in such a way that the clutch disc (6), which is axially displaceable relative to the cage (5, 65) within an axially limited axial stroke (H), is connected to the cage (5, 65) in a rotationally fixed and permanently form-fitting manner around the rotation axis (12), - the zone (55) of the actuating device is opposite the actuating device (8) without contact when the magnetic field is switched on. [2] Switchable freewheel according to claim 1, characterized byin that the friction clutch (15) has at least one friction ring (20, 67), wherein the friction ring (20, 67) is connected to the second track (3) in a rotationally fixed manner about the rotation axis (12) and is provided with at least one first friction surface (19), and in that the clutch disc (6) has at least one second friction surface (21), wherein the second friction surface (21) can be engaged in the frictionally engaged operative connection with the first friction surface (19) of the friction ring (20, 67) in an axially movable manner within the axial stroke (H), wherein the second friction surface (21) is coupled to the cage (5) via the clutch disc (6). [3] Switchable freewheel according to claim 1, characterized by that the zone (17) and the actuating device (8) are spaced apart from each other without contact by a distance (A) which is greater than the axial stroke (H). [4] Switchable freewheel according to claim 2, characterized by , the friction surfaces (19, 21) are conical. [5] Switchable freewheel according to one of the preceding claims, characterized by in that the form-locking connection (18) is formed by at least two form-locking elements (13, 14), wherein either a first form-locking element (13) of the form-locking elements (13, 14) is formed on the cage (5, 65), which forms at least one axially extending first extension (23), wherein the first extension (23) engages in a second form-locking element (14) assigned to the clutch disc (6) in a rotationally fixed manner, and / or a second form-locking element (14) of the form-locking elements (13, 14) is formed on the clutch disc (6) or the cage (5, 65), the at least one second extension (24) of which engages in a gap (25, 26) of the first form-locking element (13) or second form-locking element (14). [6] Switchable freewheel according to one of the preceding claims, characterized bythat an elastic stop (27) is arranged or clamped axially between the friction ring (67) and the clutch disc (6), wherein the clutch disc (6) is axially elastically prestressed against the elastic stop (27) in the engaged frictional operative connection. [7] Switchable freewheel according to one of the preceding claims, characterized by that the clutch disc (6) is supported radially on a first shaft (28) so as to be rotatable about the rotation axis (12) and is mounted so as to be axially displaceable, wherein the second track (3) is connected to the first shaft (28) so as to be rotationally fixed about the rotation axis (12). [8] Switchable freewheel according to claim 7, characterized by that the second track (3) is formed directly on the first shaft (28) and / or that the clutch disc (6) is radially supported and axially displaceably mounted on the first shaft (28) by means of at least one radial needle bearing (29). [9] Switchable freewheel according to one of the preceding claims, characterized in that the first track (2) is formed or fixed to a second shaft (30) which is rotatable relative to the first shaft (28) about the rotation axis (12). [10] Switchable freewheel according to claim 9, characterized by that the first shaft (28) is connected in a rotationally fixed manner to a third shaft (31) on which the second shaft (30) is rotatably mounted.

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