ELECTROMAGNETIC AND CENTRIFUGAL CLUTCH

Abstract

Clutch (50), comprising: a latch (58) which is mounted in an inner ring (47) such that it pivots between an engagement position and an out-of-engagement position, a pin (68) which is mounted in the inner ring (47) such that it slides between a first and a second position, so that the pin (68) pushes the pawl (58) in the first position into the disengaged position; and a shoe (66) configured to pivot in response to a magnetic field with respect to the inner ring (47) in order to push the pin (68) into the second position.

Description

TECHNICAL AREA

[0001] This disclosure relates to the field of vehicle couplings. In particular, the disclosure relates to an electromagnetically actuated ratchet coupling used in a hybrid electric drive. STATE OF THE ART

[0002] Many vehicles are used across a wide range of speeds, including forward and reverse. However, some engine types operate efficiently only within a narrow RPM range. Therefore, transmissions are often used that can efficiently transfer power at a variety of gear ratios. When the vehicle is traveling at low speeds, the transmission typically operates at a high gear ratio, thus increasing engine torque for better acceleration. At high speeds, operating the transmission at a low gear ratio allows for an engine speed that is conducive to smooth and fuel-efficient driving.

[0003] Some transmissions, called discrete-ratio transmissions, are configured to produce a finite number of speed ratios between an input shaft and an output shaft. If the currently selected ratio is no longer suitable, a discrete-ratio transmission must shift to another of the available speed ratios. Other transmissions, called continuously variable transmissions (CVTs), are capable of producing any speed ratio between a lower and upper limit. CVTs are able to make frequent, fine adjustments to the speed ratio that are imperceptible to the vehicle occupants.

[0004] Many transmissions use hydraulically actuated friction clutches to create different power flow paths. Hydraulic actuation is well-suited for clutches that selectively couple rotating elements because pressurized hydraulic fluid can be routed from a stationary housing to rotating components between seals. Therefore, the hydraulic actuator can rotate with any of the rotating elements. When multiple hydraulically actuated clutches are present, they often share a motor-driven pump and many of the valve body components used to regulate pressure.

[0005] German patent application DE 10 2015 116 403 A1 is known from the prior art. This describes a coupling with an inner and outer ring, a pawl which is mounted in the inner ring in such a way that it pivots between an engagement position and an out-of-engagement position, so that the contact between a cam surface of the outer ring and the pawl in the engagement position prevents a relative rotation between the inner ring and the outer ring in at least one direction.

[0006] Hybrid transmissions for vehicles improve fuel efficiency by providing energy storage. In a hybrid electric vehicle, for example, energy can be stored in a battery. The battery can be charged by operating the combustion engine to generate more energy than is currently needed for propulsion. Furthermore, energy that would otherwise be lost during braking can be recovered and stored in the battery. This stored energy can be used later, allowing the combustion engine to generate less power than is currently required for propulsion, thus reducing fuel consumption. PRESENTATION OF THE INVENTION

[0007] Couplings with the features of the independent claim are provided.

[0008] A gearbox comprises a shaft, an inner ring, a gear, an outer ring, a non-rotating coil, and a rocker arm assembly. The shaft is mounted to rotate about an axis. The inner ring is mounted to rotate with the shaft. The gear is mounted to rotate about the axis. The outer ring is mounted to rotate with the gear. The outer ring also defines a cam surface. The non-rotating coil is configured to generate a magnetic field in the inner ring in response to an electric current. The rocker arm assembly comprises a pawl, a pin, and a shoe.

[0009] The pawl is mounted in the inner ring. The pawl pivots between an engaged position and a disengaged position, such that contact between the cam surface and the pawl in the engaged position prevents relative rotation between the inner and outer rings in at least one direction. The pin is mounted in the inner ring. The pin slides between a first and a second position, such that in the first position, the pin pushes the pawl into the disengaged position. The shoe is configured to pivot in response to the magnetic field relative to the inner ring to push the pin into the second position, with a centrifugal force moving the pawl into the engaged position.

[0010] A coupling comprises an inner ring, an outer ring, a pawl, a pin, and a shoe. The outer ring defines a cam surface. The pawl is mounted in the inner ring such that it pivots between an engaged position and a disengaged position, such that the contact between the cam surface and the pawl in the engaged position prevents relative rotation between the inner and outer rings in at least one direction. The pin is mounted in the inner ring such that it slides between a first and a second position, such that the pin pushes the pawl into the disengaged position in the first position. The shoe is configured to pivot relative to the inner ring in response to a magnetic field, pushing the pin into the second position.

[0011] A coupling comprises a pawl, a pin, and a shoe. The pawl is mounted in a ring such that it pivots between an engaged and a disengaged position. The pin is mounted in the ring such that it slides between a first and a second position, so that in the first position the pin pushes the pawl into the disengaged position. The shoe is configured to pivot relative to the ring in response to a magnetic field, pushing the pin into the second position. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a schematic representation of a gear arrangement for a hybrid electric drive; Fig. Figure 2 is a cross-section of an electromagnetically actuated pawl coupling, designed for use in the gear arrangement of Fig. 1 is suitable; Fig. Figure 3 is an exploded view of the coupling; Fig. 4 is an isometric view of the coupling; Fig. 5 is a detailed cross-sectional view of the clutch in a disengaged state; Fig. Figure 6 is a detailed cross-sectional view of the coupling in a retracted state; Fig. 7 is an isometric view of another embodiment of the coupling; Fig. Figure 8 is a detailed front view of another embodiment of the rocker arm arrangement; and Fig. Figure 9 is a detailed front view of another embodiment of the rocker arm arrangement. DETAILED DESCRIPTION

[0012] Embodiments of the present disclosure are described herein. It is understood, however, that the disclosed embodiments are purely exemplary and that other embodiments may have different and alternative configurations. The figures are not necessarily to scale; some features may be exaggerated or reduced in size to show details of certain components. Therefore, certain structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for informing a person skilled in the art of how to apply the present invention in various ways.As the average person skilled in the art will know, various features illustrated and described with reference to any of the figures can be combined with features illustrated in one or more other figures to create embodiments not explicitly illustrated or described. The combinations of illustrated features provide representative embodiments for typical applications. However, various combinations and modifications of the features, consistent with the teachings of this disclosure, may be desired for specific applications or implementations.

[0013] Rotating elements of a group are rigidly connected if they are forced to rotate as a unit under all operating conditions. Rotating elements can be rigidly connected by splined connections, welding, press fits, machining from a common solid, or other means. Minor variations in rotational displacement may occur between rigidly connected elements, such as displacement due to clearance or shaft compliance. In contrast, two rotating elements are selectively connected by a switching element if the switching element forces them to rotate as a unit whenever the switching element is fully engaged, and they are free to rotate at different speeds under at least some other operating conditions. Two rotating elements are coupled if they are either rigidly coupled or selectively coupled.Two rotating elements are connected in a driveable manner if a series of gears and shafts is able to transmit power from one element to the other and generates a fixed rotational speed ratio between the two elements.

[0014] The Fig. Figure 1 schematically represents a kinematic arrangement for a power-split hybrid electric vehicle. Power is provided by an internal combustion engine 10, which is rigidly coupled to a planet carrier 12 via a transmission input shaft 11. A set of planet gears 14 is mounted so that they rotate relative to the planet carrier 12. A sun gear 16 and a ring gear 18 are each mounted so that they rotate about the same axis as the planet carrier 12 and are each meshed with the planet gears 14. A generator 20 is rigidly coupled to the sun gear 16. A pilot gear 22 is rigidly coupled to the ring gear 18 and meshes with a pilot gear 24. The pilot gear 24 is rigidly coupled to pilot gears 26 and 28 via a shaft 30. A pilot gear 32 meshes with the pilot gear 28 and is rigidly coupled to a motor 34. The feed wheel 26 engages with the feed wheel 36, which is the input of a differential 38.The differential 38 drives vehicle wheels 40 and 42, allowing slight speed differences when the vehicle turns.

[0015] The generator 20 and the motor 34 are both reversible electrical machines. The terms generator and motor are used here for descriptive purposes only. Both machines are capable of converting electrical power into mechanical power or vice versa. For example, each machine can be a synchronous motor in combination with a three-phase inverter. Both machines are electrically connected to a battery 44. Under some conditions, the internal combustion engine 10 can generate more power than is transmitted to the vehicle wheels 40 and 42, with the excess power being stored in the battery 44. Under other conditions, power can flow from the battery 44, allowing the internal combustion engine 10 to generate power that is less than the vehicle's immediate demand.For example, the combustion engine 10 can be switched off, while the power to drive the vehicles comes from the battery 44.

[0016] The powertrain of the Fig. 1 can be operated in a stepless mode in which the battery 44 neither supplies nor receives power. The torque exerted on the generator 20 and the torque exerted on the auxiliary gear 22 are both related to the torque generated by the internal combustion engine 10 based on the number of teeth of the sun gear 16 and the number of teeth of the ring gear 18. In particular: Tgen=NsunNsun+NringTeng Tgear22=NringNsun+NringTeng where T eng The torque generated by the internal combustion engine 10 is T gen The torque absorbed by generator 20 is T gear22 The torque absorbed by the bearing wheel 22 is N sun The number of teeth on the sun gear is 16 and Nring The number of teeth on the ring gear 18 is [value missing]. The rotational speed of the internal combustion engine is an average of the rotational speed of the generator and the rotational speed of the auxiliary gear 22. ωeng=NsunNsun+Nringωgen+NringNsun+Nringωgear22

[0017] When the vehicle is moving slowly, the auxiliary gear 22 rotates slowly, and the generator 20 rotates in the opposite direction to the internal combustion engine 10. The power generated by the internal combustion engine is divided by the planetary gear set. Part of the power is transmitted mechanically from the planet carrier 12 via the ring gear 18, the auxiliary gear 22, and the auxiliary gear 24 to the shaft 30. The remaining power is transmitted from the planet carrier 12 to the generator 20, which converts the power into electrical power. The motor 34 converts the electrical power into mechanical power, which is transmitted by the auxiliary gears 32 and 28 to the shaft 30. Although both power transmission paths are subject to some reactive losses, conversions between electrical and mechanical power typically involve greater power losses than purely mechanical transmissions.As the ratio of the rotational speed of shaft 30 relative to the rotational speed of the internal combustion engine 10 increases, a point is reached where the generator 20 is stationary. At this ratio, all the power is transmitted mechanically. At higher overdrive gear ratios, the generator 20 rotates in the same direction as the internal combustion engine 10. The power circulates from the generator 20 through the mechanical power flow path to shaft 30, through the intermediate gears 28 and 32 to the motor 34, which converts power into electrical power to drive the generator 20. The reactive losses associated with the circulation of power tend to make operation with overdrive gear ratios inefficient.

[0018] The powertrain of the Fig. 1 includes an additional power flow path to provide efficient power transmission at overdrive gear ratios. Specifically, the auxiliary gear 46 is mounted to rotate around the transmission input shaft 11. The auxiliary gear 48 is fixed to the shaft 30 and engages with the auxiliary gear 46. The clutch 50 selectively engages the auxiliary gear 46 with the transmission input shaft 11. When the clutch 50 is engaged, power is mechanically transmitted from the internal combustion engine 10 to the shaft 30 via the auxiliary gears 46 and 48. In this fixed-ratio mode, the battery 44 can supply additional power either via the generator 20 or via the motor 34, or it can be charged via either of the two electric machines.Using the fixed gear ratio mode for driving in a steady state significantly reduces fuel consumption, as both the combustion engine and the transmission operate efficiently.

[0019] Since the clutch 50 is the only clutch in the drivetrain of the Fig. If the use of a hydraulically actuated clutch were the case, it would require the addition of a pump and a valve body. Therefore, a different method for actuating the clutch 50 is desired. Fig. 2 to 4 represent an electromagnetically actuated clutch rocker suitable for selectively coupling the feed wheel 46 with the transmission input shaft 11. Fig. Figure 2 shows a cross-sectional view of coupling 50. Fig. Figure 3 shows a pictorial exploded view and the Fig. Figure 4 shows an assembled view. An outer ring 45 is formed integrally with the feed wheel 46, although in some embodiments it may be formed separately and connected by splines or other means. In at least one embodiment, the inner ring 47 of the clutch 50 may be a single-piece inner ring 47, but an inner ring 47 with two inner halves may also be used. During installation in the transmission, axial and radial bearings (not shown) are inserted between the inner ring 47 and the outer ring 45 to reduce friction and ensure concentricity. Three pawls 58 are held in pockets or grooves of the inner ring 47, as shown in Figure 4. Fig. Figure 4 shows the number of pawls. The number of pawls can vary between embodiments. As discussed in detail below, when the clutch 50 is disengaged, these pawls 58 are held in pockets formed in the inner ring 47. When the clutch 50 is engaged, these pawls pivot and engage a cam surface 49 in the outer ring 45. The inner ring 47 is held axially in position by a retaining ring (not shown).

[0020] After the clutch 50 is assembled, the inner ring 47 is splined to the transmission input shaft 11. A coil holder 62 and a coil 64 are attached to a front bracket (not shown) of the transmission. A wire connects the coil to a transmission control unit (not shown). Then the transmission input shaft 11 and the clutch 50 are inserted into the front bracket. A ball bearing (not shown) positions the transmission input shaft 11 relative to the front bracket and allows rotation of the transmission input shaft 11 with very low resistance. When the coil 64 is energized, a magnetic circuit is formed, as indicated by the arrows.By selecting suitable materials and controlling the positioning of the parts, the magnetic flux is guided from the coil holder 62 through the transmission input shaft 11, the inner ring 47, and directly into a shoe 66 of a rocker arm assembly 65, and then back to the coil holder 62. Secondary stray fields can also guide the magnetic flux from the coil holder 62 through the transmission input shaft 11, the outer ring 45, and the shoe 66 of the rocker arm assembly 65, and then back to the coil holder 62. The shoe 66 and the rocker arm assembly 65 are discussed in more detail below.

[0021] The primary flux has an air gap between the shoes 66 and the coil holder 62. The secondary flux flows through several air gaps: one gap between the coil holder 62 and the transmission input shaft 11, and one gap between the inner ring 47 and the shoes 66. The air gaps act such that they pull the shoes 66 in the same direction. Using multiple air gaps to pull the shoes 66 in the same direction allows, in addition to the primary flux path, the use of secondary stray fields to make the flux path more efficient. Magnetic attraction forces are generated between the corresponding parts at each of these air gaps. Another part geometry is conceivable that would generate a magnetic field in response to an electric current in a non-rotating coil in the inner ring, including a different arrangement with varying air gaps.

[0022] The Fig. 5 and Fig. Figure 6 shows a detailed cross-sectional view of the coupling 50 perpendicular to the cross-sectional view of the Fig. 2. The Fig. 5 and Fig. Figure 6 shows the pawls 58 as part of the rocker arm assembly 65. The rocker arm assembly 65 also includes the shoe 66, a pin 68, and a preload element 70. The shoe 66 is attached to the pin 68 and is configured to engage with the coil holder 62 when the coil 64 is energized. The magnetic flux acts on the shoe 66, drawing it towards the coil holder 62. When the magnetic circuit is established, the rocker arm assembly 65 moves vertically to the coil holder 62, and the clutch 50 engages. When the coil 64 is not energized, centrifugal forces act on the rocker arm assembly 65, and the clutch 50 disengages. Fig. Figure 5 shows a detailed cross-sectional view of the rocker arm assembly 65 when the clutch 50 is disengaged. Fig. Figure 6 shows a detailed cross-sectional view of the rocker arm assembly 65 when the clutch 50 is engaged. In this embodiment, the shoe 66 is held by the pin 68 using a snap-type arrangement.

[0023] As in Fig. As explained in more detail in section 5, the shoe 66 is disengaged from the coil holder 62 and the pawl 58 is in the pocket of the inner ring 47. As stated above, the clutch 50 disengages when the pawl 58 is in the pocket of the inner ring 47. Without an electric current, the coil 64 does not generate a magnetic flux. The pin 68 is configured to slide vertically from a first position to a second position. The first position of the pin 68 is in Fig. 5 explained in more detail, and the second position of the cone is in Fig. 6 explained in more detail. When no magnetic flux is present, the centrifugal forces acting on the rocker arm assembly 65 allow the pin 68 to engage the pawl 58. The pin 68 slides vertically in a channel 72 formed on the inner ring 47 into the first position to push the pawl 58 away from the cam surface 49 of the outer ring 45. The force of the pin 68 on the pawl 58 overcomes the centrifugal force acting on a center of gravity 61 of the pawl 58 and forces the pawl 58 to maintain a stowed or out-of-engagement position. As in Fig. As shown in Figure 5, the inner ring 47 rotates freely relative to the outer ring 45 and the clutch 50 is disengaged when the pawl 58 is in the stowed position.

[0024] The rocker arm assembly 65 can further utilize the preload element 70 to assist the pin 68 in forcing the pawl 58 to remain in the stowed position. When no centrifugal forces are present, the pawl 58 can unintentionally engage the cam surface 49 of the outer ring 45. The preload element 70 preloads the pawl 58, thereby exerting a spring force on the pawl 58 when no centrifugal forces are present. The spring force of the preload element 70 allows the pawl 58 to maintain the stowed position and prevents unintentional engagement of the clutch 50. The preload element 70 is configured to overcome gravity and any other unwanted forces that could cause the pawl 58 to engage the cam surface 49 of the outer ring 45.

[0025] The Fig. Figure 5 shows the shoe 66 having a chamfered end 98. The chamfered end 98 of the shoe 66 allows it to be mounted so that it rotates on the pin 68. When the pawl 58 is disengaged from the outer ring 45 and stowed in the inner ring 47, the shoe 66 is displaced angularly on the pin 68 with respect to the spool holder 62. For example, both the preload element 70 and centrifugal force compel the pin 68 to engage the pawl 58 at its first end 59. As indicated above, the engagement between the pin 68 and the pawl 58 forces the pawl 58 to stow in the inner ring 47, and the clutch 50 is disengaged. Therefore, the pin 68 moves laterally in the channel 72 and is linearly offset relative to the coil holder 62.Because the beveled end 98 of the shoe 66 is mounted to rotate on the pin 68, an angular displacement of the shoe 66 by an angle α is caused when the clutch 50 is disengaged relative to the coil holder 62. The angle α can be optimized to ensure efficient engagement between the shoe 66 and the coil holder 62 based on the magnetic flux generated by the coil 64.

[0026] The shoe 66 can define an arc shape. In particular, the shoe 66 is concentric with the coil holder 62 and is configured to engage the coil holder 62 by interaction with a magnetic flux. The introduction of a magnetic flux forces the shoe 66 to displace at an angle relative to the coil holder 62 at the chamfered end 98, so that the shoe 66 engages the coil holder 62. An angular displacement of the shoe 66 at the chamfered end 98 forces the pin 68 to move in the channel 72 toward the coil holder 62. The angular displacement of the chamfered end 98 of the shoe 66, as well as the linear displacement of the pin 68, allows the pawl 58 to rotate due to the centrifugal forces of the inner ring 47 and extend out of the inner ring 47 and engage with the outer ring 45.When the pawl 58 engages the outer ring 45, the inner ring 47 rotates at the same speed as the outer ring 45 and the clutch 50 is engaged.

[0027] As in Fig. As shown in more detail in Figure 6, the shoe 66 engages in the coil holder 62, thereby allowing the pawl 58 to rotate about a pivot point 63. The magnetic flux generates the magnetic attraction between the shoe 66 and the coil holder 62, which overcomes the centrifugal force of the pin 68. The compensation of the centrifugal force by the magnetic attraction forces the pin 68 to slide vertically into the second position, allowing the pawl 58 to spring out of a stowed position and move into an engagement position in the inner ring 47. The pin 68 is configured to engage with the latch 58, and when the magnetic circuit is generated, the pin 68 disengages from the latch 58. As the pin 68 slides into the second position, the centrifugal forces acting on the center of gravity 61 of the latch 58 cause the latch 58 to rotate about a pivot point 63.Rotation about a pivot point 63 allows the pawl 58 to engage with the cam surface 49 of the outer ring 45. The engagement between the pawl 58 and the cam surface 49 of the outer ring 45 causes simultaneous rotation of the outer ring 45 and the inner ring 47.

[0028] The concentricity between the shoe 66 and the coil holder 62 ensures a uniform interaction with the magnetic flux when the rocker arm assembly 65 is engaged. This uniform interaction with the magnetic flux ensures that the attractive force generated by the magnetic circuit between the shoe 66 and the coil holder 62 is strong enough to maintain engagement between the shoe 66 and the coil holder 62. This allows the pawl 58 to maintain engagement with the cam surface 49 of the outer ring 45 using the centrifugal force of the rotating inner ring 47.

[0029] The Fig. Figure 7 shows a pictorial, assembled view of another embodiment of the coupling 50 before installation in the gearbox. Fig. Figure 7 shows an embodiment of the coupling 50 with two pawls 58. The in Fig. The rocker arm arrangement 65 shown in Figure 7 uses a variety of shoes 66 to engage and disengage the clutch 50. The in Fig. The shoes 66 shown are attached to the pin 68 at a first end 82 of a first part 84. The first end 82 can be mechanically attached to the pin 68. For example, the first end 82 of the first part 84 of the shoes 66 can be welded, clipped, glued, or fastened to the pin by design. The first part 84 defines an arc-shaped section that is concentric with the spool holder 62. The shoes 66 rotate about a pin 80. The pin 80 is defined and attached to the inner ring 47 and can be configured to rotatably support the shoes 66 on the inner ring 47. The pin 80 can be fastened to the inner ring 47 through the shoes 66 between the first part 84 and a second part 86 of the shoes 66.

[0030] Referring again to the embodiment of Fig. The second part 86, comprising the two pawls 58, includes a second end 88. This second end 88 has a thickness 94 that is greater than that of the first end 82 of the first part 84. Because the second end 88 of the shoes 66 is thicker than the first end 82, the second part 86 can increase the attractive force acting on the shoes 66. In particular, the density of the magnetic flux is mainly focused on the first end 82 of the first part 84 of the shoes 66. However, a thicker second end 88 of the second part 86 can increase the flux interacting with the shoes 66. By increasing the magnetic flux interacting with the shoes 66, a faster response time of the rocker arm assembly 65 and a stronger engagement between the shoes 66 and the coil holder 62 are achieved. This allows for more efficient engagement of the clutch 50.

[0031] The Fig. 8 and Fig. Figure 9 shows a detailed front view of another embodiment of the rocker arm arrangement 65. Fig. Figure 8 shows a detailed front view of the rocker arm assembly 65 when the pawl 58 is disengaged from the outer ring 45. As stated above, when disengaged from the outer ring 45, the pawl 58 is stowed within the inner ring 47. Fig. Figure 9 shows a detailed front view of the rocker arm assembly 65 when the pawl 58 is engaged with the outer ring 45. As stated above, the clutch 50 is engaged and the inner ring 47 rotates at the same speed as the outer ring 45 when the pawl 58 is engaged with the outer ring 45.

[0032] The pin 68 is shown as a pin with a first part 76 and a second part 78. The first part 76 is shown as thicker than the second part 78. In at least one other embodiment, the pin 68 can have a uniform thickness. Furthermore, the pin 68 is shown as a pin with a rectangular cross-section. In at least one other embodiment, the pin 68 can have other cross-sectional areas, for example, but not limited to, cylindrical, square, or any other cross-sectional area that allows the pin 68 to move in the channel 72 and act on the latch 58. The preload element 70 is shown on the second part 78 of the pin 68. The preload element 70 can also be configured to expand and contract in the channel 72. In at least one embodiment, the preload element 70 can be a spring.

[0033] As in the embodiments of the Fig. 8 and Fig.As shown in Figure 9, the shoe 66 is attached to the pin 68 by means of a pin 80. The pin 80 can attach the shoe 66 to the pin 68 substantially at the center 81 of the pin 68. Positioning the pin 80 centrally on the pin 68 allows the shoe 66 to rotate about the pin 80. In at least one other embodiment, the shoe 66 can be attached to the pin 68 offset from the center 81 of the pin 68. Creating a pivot point between the shoe 66 and the pin 68 about the pin 80 reduces the air gap between the shoe 66 and the coil holder 62. The position of the pin 80 on the pin 68 and on the shoe 66 can further optimize the response of the shoe 66 to the magnetic flux. For example, an angle α can define the air gap between the shoe 66 and the coil holder 62.The angle α can be optimized on the basis of the position of the pin 80 either on the pin 68, on the shoe 66 or on both the pin 68 and the shoe 66 in order to improve the response of the rocker arm assembly 65 when engaging the clutch 50.

[0034] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the invention. Rather, the words used in the description are descriptive rather than limiting, and it is understood that various modifications can be made without deviating from the basic concept and scope of protection of the invention. Furthermore, the features of different embodiments can be combined to develop further embodiments of the invention.

[0035] It is further described as follows: A. Gearbox, including: a shaft that is mounted in such a way that it rotates around an axis; an inner ring that is attached in such a way that it rotates with the shaft; a gear that is mounted in such a way that it rotates around the axis; an outer ring which is attached in such a way that it rotates with the gear, the outer ring defining a cam surface; a non-rotating coil configured to generate a magnetic field in the inner ring in response to an electric current; and a rocker arm arrangement comprising a latch which is mounted in the inner ring in such a way that it pivots between an engagement position and an out-of-engagement position, so that the contact between the cam surface and the pawl in the engagement position, a relative rotation between the inner ring and the outer ring in at least one direction is prevented, a pin which is mounted in the inner ring in such a way that it slides between a first and a second position, so that the pin pushes the pawl in the first position into the out-of-engage position, and a shoe configured to pivot in response to the magnetic field with respect to the inner ring to push the pin into the second position, with centrifugal force moving the pawl into the engagement position. B. Gearbox according to claim A, wherein the rocker arm arrangement further comprises a preloading element arranged at a first end of the pin. C. Gearbox according to claim A, wherein the shoe is supported by the pin and is configured to rotate about a pin in the inner ring. D. Gearbox according to claim C, wherein the shoe has a first end and a second end, wherein the second end has a thickness greater than the first end, wherein the second end is configured to interact with the magnetic field. E. Clutch, comprehensive: an inner ring; an outer ring that defines a cam surface; a pawl mounted in the inner ring such that it pivots between an engaged position and a disengaged position, such that the contact between the cam surface and the pawl in the engaged position prevents relative rotation between the inner ring and the outer ring in at least one direction; a pin mounted in the inner ring such that it slides between a first and a second position, such that the pin pushes the pawl into the disengaged position in the first position; and a shoe configured to pivot in response to a magnetic field relative to the inner ring in order to push the pin into the second position. F. Coupling according to claim E, wherein the engagement position of the pawl prevents a relative rotation of the inner ring and the outer ring in exactly one direction. G. Coupling according to claim E, further comprising a non-rotating coil configured to generate a magnetic field in the inner ring in response to an electric current. H. Coupling according to claim E, wherein the inner ring radial is arranged inside the outer ring. I. Coupling according to claim E, wherein the pawl has a center of gravity arranged such that the centrifugal force causes the pawl to pivot about a pivot point in the engagement position when the pin is in the second position. J. Kupplung, comprehensive: a latch which is mounted in a ring in such a way that it pivots between an engagement position and a disengaged position, a pin which is mounted in the ring in such a way that it slides between a first and a second position, so that the pin pushes the pawl in the first position into the disengaged position; and a shoe configured to pivot in response to a magnetic field relative to the ring in order to push the pin into the second position. K. Coupling according to claim J, which further comprises a pin arranged such that the pin connects the shoe to the pin. L. Coupling according to claim K, wherein the shoe is configured to rotate around the pin in response to the magnetic field. M. Coupling according to claim K, wherein the pin is substantially centrally located in the middle of the shoe and substantially in the middle of the pin. N. Coupling according to claim K, wherein the pin is offset to the center of the shoe and is attached centrally to the pin. O. Coupling according to claim K, wherein the pin is offset from the center of the pin and is attached centrally to the shoe. P. Coupling according to claim K, wherein the pin is attached offset to the center of the shoe and offset to the center of the pin.

Claims

[1] Clutch (50), comprising: a latch (58) which is mounted in an inner ring (47) such that it pivots between an engagement position and an out-of-engagement position, a pin (68) which is mounted in the inner ring (47) such that it slides between a first and a second position, so that the pin (68) pushes the pawl (58) in the first position into the disengaged position; and a shoe (66) configured to pivot in response to a magnetic field with respect to the inner ring (47) in order to push the pin (68) into the second position. [2] Coupling (50) according to claim 1, further comprising: an outer ring (45) that defines a cam surface (49); and the pawl (58) is mounted in the inner ring (47) such that it pivots between an engagement position and an out-of-engagement position, so that the contact between the cam surface (49) and the pawl (58) in the engagement position prevents a relative rotation between the inner ring (47) and the outer ring (45) in at least one direction. [3] Coupling (50) according to claim 2, wherein the engagement position of the pawl (58) prevents a relative rotation of the inner ring (47) and the outer ring (45) in exactly one direction. [4] Coupling (50) according to claim 2, further comprising a non-rotating coil (64) configured to generate a magnetic field in the inner ring (47) in response to an electric current. [5] Coupling (50) according to claim 2, wherein the inner ring (47) is arranged radially inside the outer ring (45). [6] Coupling (50) according to claim 2, wherein the pawl (58) has a center of gravity (61) arranged such that the centrifugal force causes the pawl (58) to pivot about a pivot point (63) in the engagement position when the pin (68) is in the second position. [7] Coupling according to claim 1, further comprising a pin (80) arranged such that the pin (80) connects the shoe (66) to the pin (68). [8] Coupling (50) according to claim 7, wherein the shoe (66) is configured to rotate around the pin (68) in response to the magnetic field. [9] Coupling (50) according to claim 7, wherein the pin (80) is attached centrally to the shoe (66) in the center of the pin (68). [10] Coupling (50) according to claim 7, wherein the pin (80) is offset from the center of the shoe (66) and is attached centrally to the pin (68). [11] Coupling (50) according to claim 7, wherein the pin (80) is offset from the center of the pin (68) and is attached centrally to the shoe (66). [12] Coupling (50) according to claim 7, wherein the pin (80) is attached offset from the center of the shoe (66) and offset from the center of the pin (68).

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