Electromagnetically shiftable form-fitting engagement clutch

Abstract

The invention relates to an electromagnetically shiftable form-fitting engagement clutch having a shift sleeve arranged on a shaft, a clutch body coaxially aligned with the shaft, and a stator having at least one energizable drive coil for adjusting the shift sleeve along the shaft, there is a form-fitting engagement between the shift sleeve and the clutch body and thus a rotational connection between the shaft and the clutch body. Furthermore, the form-fitting clutch has a fixed sensor arrangement arranged adjacent to the shift sleeve and comprising at least one Hall sensor and at least two magnets, which magnetically enclose the at least one Hall sensor and are permanently fixed relative to the at least one Hall sensor, wherein the magnets are directed towards the shift sleeve and have opposite polarities with respect to each other. The sensor arrangement is adjacent to the shift sleeve in a radial direction to be spaced apart from the shift sleeve by a radial clearance such that axial movement of the shift sleeve is detected by the Hall sensor by a reduction in the radial clearance.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electromagnetic shiftable positive engagement clutch. BACKGROUND

[0002] If torque is to be transmitted from one shaft to another coaxially aligned shaft temporarily without the two shafts being permanently connected, a clutch is usually employed. Here, a distinction is made between friction engagement clutches and positive engagement clutches. The present invention relates to positive engagement clutches, which are referred to herein as positive engagement clutches. Positive engagement clutches include, for example, tooth clutches and claw clutches.

[0003] For positive engagement clutches, shift sleeves which can be displaced are usually employed. These shift sleeves comprise one toothed portion or also a plurality of different toothed portions, which engage with mating toothed portions, so that a positive engagement, i.e. an engagement in the positive sense, is produced which allows torque to be transmitted from a first shaft to a second shaft.

[0004] What is disclosed in the prior art is an electromagnetic clutch in which the adjustment of the shift sleeve takes place by means of a drive coil which exerts a magnetic force on the shift sleeve. In this type of clutch, the shift sleeve can be moved in one direction starting from a disengaged position in order to move the shift sleeve into engagement with the clutch body. This is referred to as an overrunning clutch.

[0005] Furthermore, double-sided clutches are known in which the shift sleeve can be moved in the opposite direction starting from a disengaged position in order to move the shift sleeve into engagement with a different, axially spaced clutch body.

[0006] In particular in electromagnetic shiftable positive engagement clutches, a control is provided which controls the displacement of the shift sleeve by means of a control command. For an optimum possible clutch operating process, it is necessary here to know the current position, also referred to as the engagement position, of the shift sleeve. The reason for this is that for each control command transmitted to the electromagnetic shiftable positive engagement clutch, the current engagement state should first be analysed, so that the control should be able to ask the position of the shift sleeve at any time.

[0007] In the prior art, the shift state or the engagement position of the shift sleeve is determined using indirect measurement, for example by means of the current state of the stator or the speed of the shafts to be connected.

[0008] As an alternative, sensors can be incorporated in the housing of the positive engagement clutch. This usually also involves indirect measurement which is carried out by means of additional actuating components, such as, for example, a disc which is coupled to the displaceable part, in particular to the shift sleeve.

[0009] A switch can also be used in order to determine the end position of the shift sleeve, i.e. the engaged position or the disengaged position of the shift sleeve. Here, the switch is actuated by a dedicated actuation portion when the shift sleeve is in the engaged position.

[0010] As an alternative to a switch, a stroke measurement system can also be used which is likewise actuated by an additional component.

[0011] The methods known from the prior art for detecting the position of a shift sleeve therefore differ in that indirect measurements are involved which require additional components for scanning or actuation. Direct and precise determination at the actual clutch engagement position is therefore not possible; instead, additional components are always required.

[0012] In addition, the position of the shift sleeve is usually detected in the axial direction, so that the installation space required for the positively locking clutch is increased.

[0013] Furthermore, the additionally required components and the increased installation space increase the manufacturing costs of the positively locking clutch.

[0014] Furthermore, these measurement techniques usually require precise calibration of the sensor with respect to the point being measured, which is usually very complex and therefore cost-intensive. SUMMARY

[0015] It is therefore an object of the present application to provide an electromagnetically shiftable positively locking clutch in which the engagement position is determined by means of a direct measurement. It is a further object to keep the required installation space and the number of components required as low as possible.

[0016] According to the application, this object is achieved by an electromagnetically shift-able positive engagement clutch, comprising a shift sleeve which is arranged on a shaft for co-rotation with the shaft and which is linearly displaceable along the shaft between a clutch engagement position and a clutch disengagement position. Furthermore, the positive engagement clutch comprises at least one clutch body which is coaxially aligned with the shaft and a stator having at least one energizable drive coil for adjusting the shift sleeve along the shaft, wherein in the clutch engagement position there is a positive engagement between the shift sleeve and the clutch body and thus a rotational connection between the shaft and the clutch body. Furthermore, the positive engagement clutch comprises a fixed sensor device which is arranged adjacent to the shift sleeve and which comprises at least one Hall sensor and at least two magnets which magnetically enclose the at least one Hall sensor and are permanently fixed relative to the at least one Hall sensor, wherein the magnets are directed towards the shift sleeve and have opposite polarities relative to each other. The sensor device is adjacent to the shift sleeve in the radial direction to be spaced apart from the shift sleeve by a radial gap, such that an axial movement of the shift sleeve is detected by the Hall sensor by a reduction of the radial gap.

[0017] In other words, the at least one Hall sensor is fixed in the clutch radially inwardly relative to the stator in the magnetic field of the two oppositely polarized magnets, such that the Hall sensor can sense a change in the radial distance from the shift sleeve and, based on this data, a controller can determine the engagement position of the shift sleeve. Since this involves a direct measurement, no additional components are required, resulting in reduced manufacturing costs. In addition, the Hall sensor is a commonly used sensor which is available at low cost and requires little space. In particular in the axial direction, almost no additional installation space is required, since the Hall sensor is adjacent to the shift sleeve in the radial direction. In particular, the exact position of the shift sleeve can be detected without or independently of a coil current.

[0018] Thus, the position of the shift sleeve is determined using the Hall effect. This means that a change in voltage is measured in a current-carrying conductor located in a magnetic field. The change in the magnetic field as the shift sleeve is displaced results exactly in this change in voltage.

[0019] Since the Hall sensor is magnetically enclosed by at least two oppositely polarized magnets, the influence of the magnetic field of the drive coil, which can lead to uncontrolled changes in the Hall effect, can be prevented. Thus, the magnets serve to magnetically shield the Hall sensor.

[0020] In addition, this arrangement allows the permanent magnets fastened to the shift sleeve to be dispensed with. This can significantly reduce production costs, since permanent magnets suitable for the shift sleeve are ring-shaped custom products, which generally significantly increase production costs.

[0021] Preferably, the shift sleeve can have a ramp on the outer side opposite the sensor device, which ramp constitutes a detection area for the sensor device and delimits a radial gap on a portion of the shift sleeve, wherein the width of the gap changes during the axial movement of the shift sleeve due to the ramp. The ramp on the outer side of the shift sleeve allows the accurate engagement position of the shift sleeve to be determined at all times, not only whether the shift sleeve is currently in the clutch engagement position or in the clutch disengagement position.

[0022] Therefore, the section of the shift sleeve comprising the ramp preferably corresponds at least to the necessary stroke of the form-fit engagement clutch, i.e. the necessary shift travel. In this way, it can be ensured that the reduction or increase of the radial gap caused by each movement of the shift sleeve is detected by the Hall sensor.

[0023] According to one embodiment, the ramp is formed by a tapered axial edge of the shift sleeve.

[0024] Alternatively, it is also conceivable that the shift sleeve has a gradual change instead of a ramp, so that the position of the shift sleeve can be determined in discrete steps.

[0025] According to a further embodiment, the sensor device comprises a magnetic short-circuit bridge adjacent to one end of the magnets, thereby magnetically coupling the magnets. The use of such a short-circuit bridge allows the flux of the magnetic field to be directed, i.e. the flux from one magnet to the other magnet can be increased. Thereby, the Hall sensor is better shielded from the magnetic field of the stator and the signal provided by the Hall sensor is amplified, so that an overall higher resolution can be achieved.

[0026] According to a preferred embodiment, the at least two magnets are magnetically connected to each other at the end of the magnets facing away from the shift sleeve by a short-circuit bridge. This further enhances the shielding of the Hall sensor from the magnetic field of the drive coil, so that an uncontrolled change of the Hall effect is effectively prevented. Therefore, the short-circuit bridge is preferably made of a soft magnetic material.

[0027] According to one embodiment, the short-circuit bridge is subdivided into a first bridge portion and a second bridge portion. The first bridge portion and the second bridge portion are arranged such that a gap is created between the two bridge portions and the Hall sensor can be arranged in the gap between the first bridge portion and the second bridge portion. By arranging the Hall sensor between the two bridge portions of the short-circuit bridge, the signal is again amplified compared to the use of a continuous short-circuit bridge, so that an even higher resolution can be achieved.

[0028] According to a preferred embodiment, each of the magnets has a soft magnetic material arranged on an end of the magnet facing away from the separate short-circuit bridge. This material also serves to guide the magnetic flux in order to amplify the signal of the Hall sensor and to prevent unwanted changes in the Hall effect due to the magnetic field generated by the stator.

[0029] According to an alternative embodiment, the sensor device comprises at least two Hall sensors, each of the Hall sensors having a magnet associated with the Hall sensor, which magnet is adjacent to the associated Hall sensor. This arrangement also shields the Hall sensor from the magnetic field of the drive coil, so that uncontrolled changes in the Hall effect will not distort the measurement of the Hall sensor.

[0030] Preferably, the Hall sensor is adjacent to an end of the respective associated magnet close to the shift sleeve and thus located between the magnet and the shift sleeve. In this way, the distance between the Hall sensor and the shift sleeve can be kept as short as possible in order to obtain as accurate a measurement as possible, since the accuracy of the measurement decreases as the distance between the sensor and the shift sleeve increases. In particular, since the clutch control stroke in the positively locking, electromagnetically shiftable engagement clutch is in the order of a few millimeters, the precise resolution of the Hall sensor is extremely important.

[0031] According to one embodiment, the at least one Hall sensor is mounted on the circuit board directly or by means of one of the at least two magnets. This makes it easier to fasten the sensor device and allows the sensor signal to be transmitted directly to the controller.

[0032] The magnets can be arranged parallel to one another and / or be arranged on the same side of the circuit board, which also comprises the Hall sensor. By the parallel arrangement of the magnets, it can be ensured that the magnets are arranged with exactly opposite polarity, the required magnetic flux is obtained and precise measurements are performed.

[0033] The magnets can be permanent magnets or electromagnets.

[0034] According to one embodiment, at least two sensor devices are provided, which are arranged offset from one another in the circumferential direction, so that unequal displacements of the shift sleeve, for example due to a tilt of the shift sleeve, can be detected at an early stage. The shift sleeve can thus also be controlled such that the tilting movement is neutralized, or a quick disengagement and reengagement of the clutch can be performed briefly.

[0035] According to one embodiment, the sensor device is received in a sensor housing, which is attached to the stator housing.

[0036] Preferably, only a single clutch body is associated with the shift sleeve, so that the sensor device is arranged on an axial side of the shift sleeve which is remote from the clutch body. This allows mounting space problems to be prevented, since the sensor does not need to be arranged between the clutch body and the shift sleeve or immediately adjacent to the clutch body or above the clutch body. BRIEF DESCRIPTION OF DRAWINGS

[0037] Further advantages and features of the present application will become clear from the following description and from the referenced drawings, in which:

[0038] - Figure 1 A cross-sectional view of an electromagnetically shiftable positive engagement clutch according to the present application is shown, in which the shift sleeve is in the disengaged position;

[0039] - Figure 2 A detailed view of the positive engagement clutch shown in Figure 1 in the region of the sensor device is shown;

[0040] - Figure 3 A detailed view of the sensor device is shown in cross-section;

[0041] - Figure 4 Another embodiment of a positive engagement clutch according to the present application with two sensor devices is shown in cross-section;

[0042] - Figure 5 A top view of the positive engagement clutch shown in Figure 4 is shown;

[0043] - Figure 6 A detailed perspective view of an alternative sensor device is shown;

[0044] - Figure 7 A schematic view of the sensor device shown in Figure 5 is shown; and

[0045] - Figure 8 A schematic view of another alternative configuration of the sensor device is shown. DETAILED DESCRIPTION

[0046] Figure 1 An electromagnetically shiftable positive engagement clutch 10 is shown, which has the function of coupling a first shaft 12 and a second shaft 14 which is coaxially aligned with the first shaft 12 to one another by opening and closing.

[0047] Figure 1 The positive engagement clutch 10 shown in is an electromagnetic tooth clutch, which has teeth which project radially inwards and radially outwards and engage with one another.

[0048] However, the electromagnetically shift-able positive engagement clutch 10 can also be any other type of toothed clutch. The only important thing is that the connection is established by a positive engagement.

[0049] The electromagnetically shift-able positive engagement clutch 10 comprises a shift sleeve 16 which comprises a first toothing 18 which is laterally along the circumference.

[0050] Furthermore, the shift sleeve 16 is arranged on the first shaft 12 for co-rotation with the first shaft 12 and is axially adjustable along the first shaft 12 between a clutch engagement position and a clutch disengagement position along a toothing 19 which couples the shaft 12 and the shift sleeve 16. Figure 1 The shift sleeve 16 is shown in the disengaged position.

[0051] The second shaft 14 has associated therewith a single clutch body 20 which is coupled to the second shaft 14 for co-rotation with the second shaft 14.

[0052] The clutch body 20 comprises a second toothing 22 which is arranged along the outer circumference of the clutch body 20. Furthermore, the clutch body 20 is coaxially aligned with the first shaft 12.

[0053] However, it is also conceivable that the clutch body 20 forms a part of the second shaft 14 and is formed integrally with the second shaft 14.

[0054] The first toothing 18 and the second toothing 22 together form a clutch tooth system 24 and serve to form a positive engagement between the shift sleeve 16 and the clutch body 20 in the engagement position of the shift sleeve 16.

[0055] The clutch tooth system 24 formed by the first toothing 18 and the second toothing 22 can have an undercut at least on the teeth of the first toothing 18 and / or on the teeth of the second toothing 22 which is configured such that, when the shift sleeve 16 is in the clutch engagement position and a torque is applied to the positive engagement clutch 10, the shift sleeve 16 is additionally displaced towards the clutch body 20 because the circumferential force is converted into an axial displacement force. This can be achieved, for example, by an undercut which widens wedge-shaped such that a wedge effect is produced in the direction of the clutch engagement position when a torque is transmitted.

[0056] Furthermore, a stator 26 is provided which comprises a stator housing 28 and a drive coil 30 which is at least partially received in the stator housing 28.

[0057] The stator housing 28 comprises a housing pot 32 which extends along the circumference of the drive coil 30 and along the facing sides of the drive coil 30.

[0058] In addition, the stator housing 28 includes a housing ring 34 that extends along the circumference of the drive coil 30 and also extends on the opposite side of the drive coil 30 to the housing tank 32.

[0059] The drive coil 30 is used to linearly adjust the shift sleeve 16 along the first shaft 12 toward the engagement position until the clutch body 20.

[0060] Alternatively, it is conceivable that the drive coil 30 is used to adjust the shift sleeve 16 toward the disengaged position along the first axis 12.

[0061] The adjustment of the shift sleeve 16 is achieved by using the magnetic force applied to the shift sleeve 16 when the drive coil 30 is energized.

[0062] In order to allow the shift sleeve to return to the disengaged position, an elastic spring unit 40 is provided. The shift sleeve 16 is connected to the first shaft 12 by means of the elastic spring unit 40 so that it can be moved in the axial direction.

[0063] The elastic spring unit 40 is arranged between the shift sleeve 16 and the first shaft 12 such that a relative displacement of the shift sleeve 16 in the axial direction toward the clutch engagement position causes compression of the elastic spring unit 40. This generates a restoring force exerted by the first elastic spring unit 40 on the shift sleeve 16.

[0064] The restoring force acts in the opposite manner to the magnetic force of the drive coil 30.

[0065] The elastic spring unit 40 is arranged in the recess in the shaft 12 and presses axially against the wall on the shaft on one hand, and axially against the disc-shaped member 41 fastened to the shift sleeve 16 on the other hand.

[0066] Therefore, the elastic spring unit 40 is housed in a space that is radially defined on the inside by the first shaft 12 and on the outside by the shift sleeve 16.

[0067] The spring unit 40 may preferably be a wave spring or a wave spring assembly.

[0068] For example, especially in Figure 2 As can be seen in the detailed view, the shape-fitting clutch 10 of the first embodiment shown here also includes a sensor device 42.

[0069] For example, especially in Figure 3 As can be seen, the sensor device 42 includes at least two Hall sensors 44 and two magnets 46, the two magnets 46 magnetically enclosing the Hall sensors 44 and being directly adjacent to the Hall sensors 44.

[0070] The magnets 46 are permanent magnets or electromagnets for providing a stable magnetic field for the Hall sensors 44.

[0071] For this purpose, the magnets 46 each have one end pointing towards the shift sleeve 16 and are permanently fixed relative to the Hall sensors 44 or are fastened to the Hall sensors 44. In order to ensure the best possible magnetic flux, one magnet 46 points with a positive pole towards the shift sleeve 16, while the other magnet 46 points with a negative pole towards the shift sleeve 16, i.e. they have opposite polarity.

[0072] In the exemplary embodiment shown here, each of the Hall sensors 44 has one of the magnets 46 associated therewith. As mentioned, the respective magnet 46 is adjacent to the associated Hall sensor 44.

[0073] In this context, the Hall sensors 44 are arranged at the end of the respective magnet 46 close to the shift sleeve 16, such that the Hall sensors 44 are disposed between the associated magnet 46 and the shift sleeve 16.

[0074] The sensor device 42 is received in a sensor housing 48, which is fastened laterally to the stator housing 28, see Figure 2 .

[0075] For example, the sensor housing 48 can be fastened to the stator housing 28 by means of screws 50.

[0076] As can be clearly seen in particular in Figure 3 , the two Hall sensors 44 are each attached to the circuit board 52 by means of one of the magnets 46.

[0077] The Hall sensors 44 are each fastened here to that end of the magnets 46 pointing towards the shift sleeve 16.

[0078] The arrangement of the Hall sensors 44 between the magnets 46 and the shift sleeve 16 is particularly advantageous, since the measurement accuracy of the Hall sensors 44 decreases with increasing distance. Therefore, the Hall sensors 44 should be arranged as close as possible to the shift sleeve 16 in order to be able to determine the engagement position of the shift sleeve 16 as accurately as possible.

[0079] The magnets 46 are not only arranged with opposite polarity but also parallel to one another, as can be seen in Figure 3 . This allows a defined magnetic flux to be ensured between the magnets 46.

[0080] In addition, the two magnets 46 are provided on the same side of the circuit board 52.

[0081] In order to be able to determine the engagement position of the shift sleeve 16, the sensor device 42 is fastened to the stator housing 28 in the radial direction, such that the sensor device 42 is spaced apart from the shift sleeve 16 by a radial clearance. When the shift sleeve 16 is axially displaced, the radial clearance is reduced or increased depending on the direction of displacement of the shift sleeve 16, as will be discussed later, which leads to a change in the magnetic field as detected by the Hall sensor 44 or the plurality of Hall sensors 44.

[0082] In order to not only allow a distinction between the clutch engagement position and the clutch disengagement position, but also to be able to determine the precise engagement position of the shift sleeve 16 at any time, the shift sleeve 16 comprises a ramp 54 on its outer side, which is opposite the sensor device 42. The ramp 54 constitutes a detection area for the sensor device 42 and defines the radial clearance over a portion of the shift sleeve 16.

[0083] Preferably, the ramp 54 is formed by a tapered axial edge of the shift sleeve 16.

[0084] As shown in Figure 1 , only a single clutch body 20 is associated with the shift sleeve 16, such that the sensor device 42 can be arranged on the side of the shift sleeve 16 axially remote from the clutch body 20.

[0085] The function and operation of the form-fit engagement clutch 10 and the determination of the engagement position of the shift sleeve 16 by means of the sensor device 42 will now be described below.

[0086] Here, the initial state consists of the disengaged position of the shift sleeve 16, as shown in Figure 1 .

[0087] Here, there is no form-fit engagement between the first toothing 18 of the shift sleeve 16 and the second toothing 22 of the clutch body 20.

[0088] In this disengaged and open state, the shift sleeve 16 is held by the resilient spring unit 40 as long as no external force of any kind exceeding the spring force of the spring unit 40 acts on the shift sleeve 16.

[0089] This form-fit engagement clutch 10 is also referred to as "normally open".

[0090] As long as the shift sleeve 16 is in the disengaged position, the radial clearance does not change and the Hall sensor 44 of the sensor device 42 does not detect a signal.

[0091] When the shift sleeve 16 is to be displaced from the disengaged position towards the clutch body 20, a sufficient voltage must first be applied to the drive coil 30.

[0092] The energization of the drive coil 30 is performed here by means of a controller 56, which is responsible for any clutch operating processes and also processes the signals of the sensor device 42 (see Figure 5 ).

[0093] The controller 56 is thus connected to both the drive coil 30 and the sensor device 42, wherein the controller 56 and the sensor device 42 are connected to one another at least in terms of signal transmission.

[0094] The connection of the controller 56 to the sensor device 42 is preferably performed via the circuit board 52, wherein the sensor device 42 can be connected to the controller 56 by means of a cable, a line and / or a plug connection.

[0095] The energization of the drive coil 30 provides a magnetic flux, which exerts a magnetic force on the shift sleeve 16 in the direction of the clutch body 20.

[0096] When the amount of the magnetic force exceeds the amount of the spring force acting on the shift sleeve 16 by the spring unit 40, a movement of the shift sleeve 16 towards the clutch body 20 will occur.

[0097] Due to the ramp 54 on the outer side of the shift sleeve 16, this displacement of the shift sleeve 16 leads to a change in the distance between the Hall sensor 44 and the ramp 54 by a reduction of the radial clearance between the sensor device 42 and the shift sleeve 16.

[0098] The movement of the shift sleeve 16 and the resulting reduction of the radial clearance in turn changes the magnetic field, which causes a change in the Hall voltage, from which the engagement position of the shift sleeve 16 can be inferred.

[0099] The shift sleeve 16 is thus in the clutch engagement position. When the drive coil 30 is energized, a magnetic holding force acts on the shift sleeve 16.

[0100] In order to ensure that each position and each position of the shift sleeve 16 between the clutch disengagement position and the clutch engagement position can be identified, the ramp 54 preferably corresponds to the necessary travel of the shift sleeve 16, i.e. the shift travel.

[0101] In the clutch engagement position, the first toothing 18 and the second toothing 22 engage with one another such that a form-fit engagement exists between the shift sleeve 16 and the clutch body 20.

[0102] As already mentioned, the first toothing 18 and / or the second toothing 22 can be provided with a lateral undercut in the axial direction and in the direction of the clutch engagement position.

[0103] If both toothing parts 18, 22 comprise undercuts, the torque transmission between the clutch body 20 and the first shaft 12 results in a force acting on the shift sleeve 16 in the direction of the clutch engagement position, i.e. towards the clutch body 20, due to a wedge effect generated between the undercuts and the contacting teeth.

[0104] Here, the force acting on the shift sleeve 16 depends significantly on the geometry of the undercuts of the toothing parts 18, 22 and on the effective torque.

[0105] When the shift sleeve 16 is in the clutch engagement position, the radial clearance does not change, so that the Hall sensor 44 cannot detect a change in the Hall voltage.

[0106] Now, when the shift sleeve 16 is to be moved back to its clutch disengagement position, it is first necessary to reduce or eliminate the magnetic force generated by energizing the drive coil 30.

[0107] If the amount of the magnetic force acting on the shift sleeve 16 is lower than the amount of the restoring force exerted by the elastic spring element 40 acting on the shift sleeve 16, this results in the shift sleeve 16 being displaced from the clutch engagement position back to the clutch disengagement position.

[0108] In this state, the shift sleeve 16 is held by the spring force of the elastic spring element 40.

[0109] When the shift sleeve 16 is displaced from the clutch engagement position to the clutch disengagement position, the radial clearance increases due to the bevel 54 provided on the outer side of the shift sleeve 16, and the Hall voltage is also detected due to the changing magnetic field.

[0110] Embodiments in which the sensor device 42 comprises a magnetic, continuous short-circuit bridge that engages the ends of the magnets 46 facing away from the shift sleeve 16 and thus connects and magnetically couples the magnets 46 to one another are not shown in the figures.

[0111] The magnetic flux between the at least two magnets 46 is guided through this short-circuit bridge, so that the Hall sensor 44 is enclosed by a stronger magnetic field. In this way, the Hall sensor 44 is effectively shielded from the magnetic field generated by the drive coil 30 against an undesired change in the Hall effect due to the magnetic field of the drive coil 30.

[0112] The short-circuit bridge is therefore preferably composed of a soft-magnetic material, such as, for example, a ferromagnetic metal or a metal oxide.

[0113] In Figure 4 A further embodiment of the form-fit engagement clutch 10 can be seen in Figure 2 and Figure 3The embodiment shown in the middle differs in that two sensor devices 42 are provided.

[0114] The configuration of the sensor devices 42 and the determination of the position of the shift sleeve 16 do not change.

[0115] As can be seen in Figure 4 The sensor devices 42 are arranged offset from one another in the circumferential direction, for example by 180 degrees.

[0116] By using at least two sensor devices 42 to determine the engagement position of the shift sleeve 16, it is possible, in addition to detecting the current engagement position, to detect whether the shift sleeve 16 is slightly tilted.

[0117] If this is the case, the controller 56 can output an appropriate control command which will cause the shift sleeve 16 to be oriented perpendicular to the first shaft 12 again.

[0118] The axial arrangement of the sensor devices 42 is apparent from Figure 5 is apparent.

[0119] Figure 6 and Figure 7 Another embodiment of a sensor device 42 is shown, which can also be used to determine the engagement position of the shift sleeve 16.

[0120] The sensor device 42 shown here comprises a magnetically separated short-circuit bridge 58. Here, the magnetic short-circuit bridge 58 is magnetically coupled to the magnet 46 and adjacent to the end of the respective magnet 46 facing away from the shift sleeve 16.

[0121] As already mentioned, such a magnetic short-circuit bridge 58 serves to guide the flux of the magnetic field of the two magnets 46 and to shield the Hall sensor 44 or the plurality of Hall sensors 44 from the magnetic field of the drive coil 30, since the magnetic field of the drive coil 30 can lead to uncontrolled changes in the Hall effect.

[0122] The signal detected by the Hall sensor 44 can thus be amplified by using the short-circuit bridge 58, so that a higher resolution can be achieved.

[0123] In the embodiment shown in Figure 6 and Figure 7 The short-circuit bridge 58 is subdivided into a first bridge portion 60 and a second bridge portion 62 in the embodiment shown in

[0124] Each of the bridge portions 60, 62 is associated with one of the magnets 46 and is attached to the side of the magnet 46 facing away from the shift sleeve 16, so that the respective bridge portion 60, 62 extends to the respective other magnet 46.

[0125] The bridge portions 60, 62 are here arranged such that a gap is created between them in which the Hall sensor 44 is arranged.

[0126] Due to the use of such a separate short-circuit bridge 58, it is sufficient to use only one Hall sensor 44.

[0127] In addition to the short-circuit bridge 58, in the embodiment shown here, on each of the magnets 46, on the end of the magnet 46 that is remote from the separate short-circuit bridge 58, a soft magnetic material 64 is optionally provided.

[0128] The soft magnetic material 64 can be the same soft magnetic material as is used for the short-circuit bridge 58.

[0129] Figure 8 An embodiment of a sensor device 42 is shown which corresponds substantially to the sensor device 42 of Figure 6 and Figure 7 The difference is that in the embodiment according to Figure 8 no soft magnetic material 64 is provided at the end of the magnet 46 that is remote from the short-circuit bridge 58.

[0130] With regard to the sensor device 42 shown in Figures 6 to 8 two corresponding sensor devices 42 can also be provided in order to also detect and correct any tilting of the shift sleeve 16.

[0131] Although in the figures a positively engaging clutch 10 has been described with one clutch body 20, the sensor device 42 can also be installed in a double-sided positively engaging clutch 10. To this end, the ramp 54 of the shift sleeve 16 can be enlarged such that the travel of the shift sleeve 16 in both directions can be covered. Alternatively, a V-shaped groove can be provided on the outer circumference of the shift sleeve.

[0132] As an alternative, the positively engaging clutch 10 can comprise two sensor devices 42, each of which is associated with one axial side of the shift sleeve 16. To this end, the shift sleeve 16 should have a ramp 54 on both sides, which defines the detection area of the respective sensor device 42.

[0133] The positively engaging clutch itself illustrated differs in that no additional parts need to be attached to the shift sleeve 16 in order to be able to detect the position of the shift sleeve 16.

Claims

1. A form-fitting clutch (10) capable of electromagnetic shifting, comprising: A shift sleeve (16) is arranged on a shaft (12) for rotating with the shaft (12) and capable of linearly displacing along the shaft (12) between a clutch engaged position and a clutch disengaged position. At least one clutch body (20) is coaxially aligned with the shaft (12); The stator (26) has at least one energized drive coil (30) for adjusting the shift sleeve (16) along the shaft (12). In the clutch engagement position, there is a form-fit engagement between the shift sleeve and the clutch body (20), and therefore a rotational connection exists between the shaft (12) and the clutch body (20). A fixed sensor device (42) is arranged adjacent to the shift sleeve (16) and includes at least one Hall sensor (44) and at least two magnets (46), the magnets (46) magnetically enclosing at least one Hall sensor (44) and permanently fixed relative to the at least one Hall sensor (44), the magnets (46) pointing towards the shift sleeve (16) and having polarities opposite to each other, and The sensor device (42) is located radially adjacent to the shift sleeve, with a radial gap between them, and the axial movement of the shift sleeve is detected by the Hall sensor (44) through the change in the radial gap.

2. The electromagnetically shiftable shape-fitting clutch (10) according to claim 1, characterized in that, The shift sleeve has an inclined surface (54) on its outer side opposite to the sensor device (42), the inclined surface (54) forming a detection area for the sensor device (42) and defining a gap on a portion of the shift sleeve, wherein the width of the gap changes due to the inclined surface (54) during axial movement of the shift sleeve.

3. The electromagnetically shiftable shape-fitting clutch (10) according to claim 2, characterized in that, The inclined surface (54) is formed by the tapered axial edge of the shift sleeve.

4. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, The sensor device (42) includes a magnetic short-circuit bridging member (58) adjacent to one end of the magnet (46) to magnetically connect the magnet (46).

5. The electromagnetically shiftable shape-fitting clutch (10) according to claim 4, characterized in that, At least two of the magnets (46) are connected to each other via the short-circuit bridge (58) at the ends of the magnets (46) away from the shift sleeve (16).

6. The electromagnetically shiftable shape-fitting clutch (10) according to claim 4 or 5, characterized in that, The short-circuit bridging component (58) is subdivided into a first bridging portion (60) and a second bridging portion (62), wherein the first bridging portion (60) and the second bridging portion (62) are arranged such that a gap is created between the two bridging portions (60, 62), and wherein the Hall sensor (44) is arranged in the gap between the first bridging portion (60) and the second bridging portion (62).

7. The electromagnetically shiftable shape-fitting clutch (10) according to claim 6, characterized in that, Each of the magnets (46) has a soft magnetic material (64) disposed on the end of the magnet (46) away from the separated short-circuit bridge (58).

8. The electromagnetically shiftable form-fitting clutch (10) according to any one of claims 1 to 5, characterized in that, The sensor device (42) includes at least two Hall sensors (44), wherein each of the Hall sensors (44) has a magnet (46) associated with the Hall sensor (44) and the magnet (46) is adjacent to the associated Hall sensor (44).

9. The electromagnetically shiftable shape-fitting clutch (10) according to claim 8, characterized in that, The Hall sensor (44) is located near the end of the corresponding associated magnet (46) close to the shift sleeve (16) and between the magnet (46) and the shift sleeve (16).

10. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, At least one of the Hall sensors (44) is mounted on the circuit board (52) directly or by means of one of the at least two magnets (46).

11. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, The magnet (46) is arranged in parallel and / or disposed on the same side of the circuit board (52) as the Hall sensor (44).

12. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, The magnet (46) is a permanent magnet or an electromagnet.

13. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, At least two of the sensor devices (42) are provided, wherein the at least two sensor devices (42) are arranged to be offset from each other in the circumferential direction.

14. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, The sensor device (42) is housed in a sensor housing (48) which is attached to a stator housing (28).

15. The electromagnetically shiftable form-fitting clutch (10) according to any one of the preceding claims, characterized in that, Only a single clutch body (20) is associated with the shift sleeve, and the sensor device (42) is located on the axial end of the shift sleeve away from the clutch body (20).

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