Drive device for vehicle

Abstract

The invention relates to a drive device for a vehicle, comprising an electric motor (3, 4) for at least temporarily driving the vehicle by supplying electric power to the electric motor (3, 4), a pedal crankshaft (2) for receiving a muscle force for at least temporarily driving the vehicle by means of the muscle force, and an output element (14) by means of which a driving force for driving the vehicle can be output by the drive device. A transmission having a predetermined transmission ratio is provided, which can be coupled on the input side to an output element (5) of the electric motor (3, 4) and on the output side via a transmission output element (9) to an output element (14) of the drive. Furthermore, a pedal crankshaft output element (12) is provided, which is coupled to the pedal crankshaft (2) and can be coupled to an output element (14) of the drive. The drive device has a torque limiting arrangement (20) which is designed to limit a torque acting on a rotor (3) of the electric motor. When the torque received by the torque limiting assembly (20) exceeds a predetermined maximum torque, the support element (8) is allowed to rotate relative to the fixed element of the drive device. At least one of the axially and radially outwardly directed surface sections (81, 82, 83, 84) of the support element (8) is designed with an outwardly raised contour.

Description

Technical Field

[0001] The present invention relates to a drive device for a vehicle that is at least temporarily driven by an electric motor and at least temporarily driven by muscle power. In particular, the present invention relates to a drive device for a vehicle in which the driving power of the electric motor and the driving power generated by muscle power can be combined and used to drive the vehicle. In particular, the present invention relates to a drive device in which the effects of concentricity deviations of components within the drive device on the operation and durability of the drive device are reduced. Background Art

[0002] In the prior art according to DE 10 2015 100 676 B3, a drive device for a bicycle or an electric-assisted bicycle is described. In this drive device, an electric motor is used to generate the driving force for the vehicle. The electric motor is coupled to an output element of the drive device via a wave gear transmission.

[0003] In the prior art according to EP 2 976 551 B1, a pin-ring transmission is described, which is a structural form of a wave gear transmission with which a predetermined transmission ratio can be provided for transmitting the drive force. Summary of the Invention

[0004] A drive device for a vehicle comprises the following components: an electric motor for at least temporarily driving the vehicle by supplying electric power to the electric motor; a pedal crankshaft for receiving muscle force to at least temporarily drive the vehicle by muscle force; and a driven element through which the drive device can output driving force for driving the vehicle; a transmission having a predetermined transmission ratio, which is coupled to an output element of the electric motor on the input side and can be coupled to a driven element of the drive device via a transmission output element on the output side; a pedal crankshaft output element coupled to the pedal crankshaft and can be coupled to the driven element of the drive device; wherein the drive device has a torque limiting assembly, which is configured to limit the torque acting in a force transmission path between the electric motor and the driven element, wherein when the torque acting on the torque limiting assembly exceeds a predetermined maximum torque, the torque support member is allowed to rotate relative to a fixed element of the drive device, thereby limiting the torque acting on the rotor of the electric motor to a permissible torque, wherein at least one of the axially and radially outwardly directed surface sections of the torque support member is designed to have an outwardly convex profile.

[0005] The drive device can be securely mounted on the vehicle. The drive device can be constructed as a component and can be mounted on the vehicle, thereby enabling a compact design. The vehicle can be set up for transporting people. Additionally, the vehicle can be set up for transporting goods. The vehicle can be constructed as a single-track vehicle. Alternatively, the vehicle can be constructed as a multi-track vehicle. The vehicle can be constructed as an electric bicycle or an electric power-assisted bicycle, wherein the vehicle can be driven not only by muscle power but also by the driving force of the electric drive device. An electric energy storage device can be provided, with which the electric motor of the drive device can be operated. In addition, a control device can be provided, with which the operation of the electric motor can be controlled. The vehicle can have pedals, which are mounted on a pedal crank shaft in order to enable the introduction of muscle power.

[0006] According to one embodiment, the torque support member is coupled to a housing of the drive device to support a reaction torque, wherein a torque limiting assembly is provided in a force transmission path between the torque support member and the housing to limit the support torque to a predetermined maximum support torque.

[0007] According to one embodiment, when the torque applied to the torque limiting assembly exceeds a predetermined maximum support torque, the torque supporting member of the transmission is allowed to rotate relative to the fixed element, thereby limiting the torque acting on the rotor of the electric motor based on the reaction torque to an allowable torque.

[0008] The torque acting on the electric motor's rotor can be generated by the electric motor's drive and the transmission's transfer function. In this case, the torque acting on the electric motor's rotor corresponds to the existing drive torque of the electric motor. The torque acting on the electric motor's rotor can also or alternatively result from loading on the transmission. In particular, when the transmission's output side is loaded, this load is at least partially transferred to the electric motor's rotor via the transmission. Additionally or alternatively, a torque surge applied to the transmission's output side can be transferred via the transmission to the electric motor's rotor.

[0009] Furthermore, the torque acting on the rotor of the electric motor can be generated by the dynamic operating mode of the drive. In particular, the torque acting on the rotor of the electric motor can be generated by dynamic operating modes associated with the mass inertia of the associated moving elements. Therefore, the torque on the rotor of the electric motor can experience significant fluctuations if there are significant speed changes in the electric motor or if speed fluctuations are caused at the output of the transmission.

[0010] According to one embodiment, the torque limiting assembly can have a friction clutch arrangement, which is preloaded by a preload element so that when a predetermined maximum torque present on the torque limiting assembly is exceeded, slip occurs in the friction clutch arrangement, thereby allowing relative movement between the torque support member and the fixed element through the torque limiting assembly.

[0011] The friction clutch device can be composed of one or more friction clutch discs. Alternatively, the friction clutch device can be composed of one or more conical elements. The friction clutch device can be arranged axially symmetrically with respect to the symmetry axis of the drive device.

[0012] According to one embodiment, the torque support component can be rotationally symmetrical and have at least one radially outwardly directed surface segment on its outer circumference, which engages with the inner circumference of the fixing element via an outwardly raised profile. The outwardly raised profile of at least one of the radially outwardly directed surface segments can be radially outwardly raised. Furthermore, the outwardly raised profile of at least one of the axially outwardly directed surface segments can be axially outwardly raised. The raised profile can be designed rotationally symmetrically about the axis of symmetry of the torque support component. The raised profile of at least one of the radially outwardly directed surface segments can be arranged completely around the torque support component. The raised profile of at least one of the radially outwardly directed surface segments can have a diameter that varies in the axial direction of the torque support component, with a maximum diameter in an axially central region of the raised profile. The raised profile of at least one of the radially outwardly directed surface segments can be designed rotationally symmetrically about the axis of symmetry of the torque support component. The raised profile of at least one of the radially outwardly directed surface segments can be arranged completely around the torque support component. The raised profile of at least one of the radially outwardly directed surface segments can be provided on the corresponding end segment of the torque support component. The raised profile of at least one of the radially outwardly directed surface segments can be a rounded projection of the surface segment with an extension that varies in the radial direction of the torque support component, the extension having a maximum axial extension in a radially central region of the raised profile.

[0013] According to one embodiment, the torque support component can be rotationally symmetrical and have at least one radially outwardly directed surface section provided thereon, which engages with a radially inwardly directed surface of a support of the preload element of the torque limiting arrangement.

[0014] According to one embodiment, the torque support component can have two surface sections on the outer circumference that are axially spaced apart from one another and point radially outwards.

[0015] According to one embodiment, the torque support component extends axially and has at least one axially outwardly directed surface section which can engage with a radial section of the securing element via an outwardly raised contour.

[0016] According to one embodiment, the torque support component extends axially and has at least one axially outwardly directed surface section which can engage with a radial section of a support of the preload element of the torque limiting arrangement via an outwardly raised contour.

[0017] According to one embodiment, two axially outwardly directed surface sections can be provided on the torque support component, which surface sections can be provided on axial end sections of the torque support component.

[0018] According to one embodiment, the outwardly bulging profile of at least one of the surface segments is configured with a predetermined bulging radius. The predetermined bulging radius for the bulging profile of the radially outwardly directed surface segment is the profile radius when viewing a longitudinal section of the torque support component in the axial direction at the outer periphery of the torque support component. The predetermined bulging radius for the bulging profile of the axially outwardly directed surface segment is the profile radius when viewing a longitudinal section of the torque support component in the axial direction at an axial end section of the torque support component.

[0019] According to one embodiment, the bulge radius of the outwardly bulging contour of the individual surface segments is designed with a predetermined bulge radius, wherein at least for the radially outwardly directed surface segments, different bulge radii can be provided in each case.

[0020] According to one embodiment, the predetermined bulge radius can be designed to compensate for concentricity deviations between the torque support component and the fixing element. According to this concept, the surface segment with the predetermined bulge radius does not completely contact the surface with which it engages, thereby allowing a certain degree of freedom of movement and preventing the torque support component from jamming. To this end, the bulge radius can be designed for predetermined dimensions of the drive device in such a way that jamming of the torque support component can be reduced or prevented. This measure allows for a secure implementation of the torque limiting function.

[0021] According to one embodiment, the fixing element is designed as a housing of the drive, and the torque support component can have an outer ring of the transmission, with which a reaction torque of the transmission can be introduced into the housing.

[0022] According to one embodiment, the transmission can be configured as a harmonic gear transmission having a housing acting as a fixed element, the housing having: an inner sleeve provided with an external tooth portion and connected to the transmission output element; an outer ring provided with an internal tooth portion, which is a torque supporting member of the transmission; and a bushing bearing that can be driven by an electric motor through the input side of the transmission, the bushing bearing being used for fluctuating deformation of the inner sleeve, wherein the outer tooth portion of the inner sleeve has a smaller number of teeth than the inner tooth portion of the outer ring, and the fluctuating deformation of the inner sleeve promotes rotation of the inner sleeve relative to the outer ring.

[0023] According to one embodiment, a driven element may be coupled to a driven wheel, which drives at least one driven wheel of the vehicle via a traction mechanism. A shift mechanism may be provided between the driven wheel and the at least one driven wheel of the vehicle, the shift mechanism being configured to stepwise change the transmission ratio between the driven wheel and the at least one driven wheel.

[0024] The traction mechanism can be a chain, which is guided through a sprocket or chain disc arrangement. If the traction mechanism is implemented as a chain, the gear shifting mechanism can be designed as a derailleur. The gear shifting mechanism designed as a derailleur can be equipped with an adjustment device that guides the traction mechanism designed as a chain to gears with different numbers of teeth. In particular, the derailleur can have multiple sprockets with different numbers of teeth on the driven wheel. Additionally or alternatively, the derailleur can have multiple chain discs with different numbers of teeth in the area of ​​the pedal crank. By guiding the chain to a predetermined combination of sprockets or chain discs, the transmission ratio between the driven wheel of the drive device and the driven wheel of the vehicle can be discretely set.

[0025] The shift mechanism can alternatively be configured as an internal transmission on the driven wheels of the vehicle. In this case, a gear transmission can be provided in the hub region of the driven wheels of the vehicle, utilizing which the transmission ratio between the driven wheels and the drive element connected to the internal transmission is discretely variable. In this case, the traction mechanism can be a chain. Alternatively, the traction mechanism can be a belt, including a toothed belt.

[0026] According to one embodiment, a freewheel can be provided in the force transmission path between the transmission output element and the driven element. The freewheel between the transmission output element and the driven element can be designed so that force can be transmitted from the transmission output element to the driven element for driving the vehicle in the forward direction.

[0027] According to another embodiment, a freewheel can be provided in the force transmission path between the pedal crankshaft output element and the driven element. The freewheel between the pedal crankshaft output element and the driven element can be designed so that force transmission from the pedal crankshaft output element to the driven element can be achieved for driving the vehicle in the forward direction.

[0028] The vehicle of the above embodiment can be designed as an electric bicycle or an electric-assisted bicycle. In particular, the vehicle can be designed as a monorail vehicle having front and rear wheels. In this case, the driven wheel of the vehicle can be the rear wheel. The drive device can be mounted on the vehicle frame. The vehicle can also include an electrical energy storage device configured to supply electrical power to the drive device. The vehicle can also include operating elements that allow the rider to operate the gear shift mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram shows a detailed view of an embodiment of a drive device; and

[0030] Figure 2 The schematic diagram shows an overall view of this embodiment of the drive device. DETAILED DESCRIPTION

[0031] The following describes the implementation methods with reference to the accompanying drawings. Figure 1 yes Figure 2 Detailed view of the embodiment shown. First, combine Figure 2 The basic structure of the drive device is explained. Figure 2 An embodiment of a drive device for a vehicle is shown in the schematic diagram. Figure 2 In the view shown, the drive is shown in section along the axis of symmetry. Figure 2 The drive device of the invention comprises a housing 1 which forms the outer periphery of the drive device. A fastening mechanism is provided on the housing 1 and is designed to fasten the drive device to a vehicle.

[0032] The pedal crankshaft 2 is located in the housing 1. It extends through the housing 1 in the axial direction and protrudes from the housing 1 at both axial ends. The pedal crankshaft 2 is rotatably supported inside the housing 1. Figure 1 The pedal crank (not shown) is designed to introduce muscle force into the pedal crank shaft 2.

[0033] The pedal crankshaft 2 has a pedal crankshaft output element 12, which in this embodiment is provided as a radial projection on the pedal crankshaft 2. A first freewheel 13 is provided on the outer circumference of the pedal crankshaft output element 12, by means of which the pedal crankshaft output element 12 can be coupled to an output element 14 of a drive device. In this embodiment, the output element 14 is designed as a sleeve-shaped element, on the inner circumference of which the first freewheel 13 is provided.

[0034] The driven element 14 is rotatably supported inside the housing 1 and protrudes axially from the housing. Figure 2 A driven wheel 15 configured as a gear is provided on the driven element 14. Thus, the rotation of the driven element 14 causes the rotation of the driven wheel 15 fixedly connected to the driven element 14.

[0035] When the pedal crankshaft 2 rotates in a first direction, which corresponds to the vehicle's forward travel, the first freewheel 13 transmits the rotation of the pedal crankshaft output element 12 to the driven element 14. Thus, in this case, the driven wheel 15 rotates in the direction corresponding to the vehicle's forward travel due to the rotation of the pedal crankshaft 2. When the pedal crankshaft 2 rotates in a direction opposite to the driven element 14, the first freewheel 13 is disengaged, and the rotation of the pedal crankshaft 2 is not transmitted to the driven wheel 15.

[0036] exist Figure 2On the left side, an electric motor is arranged in the corresponding cavity of the housing 1. The electric motor has a stator 4, which is fixedly mounted relative to the housing 1. In addition, the electric motor has a rotor 3, which is arranged radially outside the stator 4 and is rotatably supported on the housing 1 through corresponding bearings. Therefore, the electric motor with an internal stator 4 and an external rotor 3 is constructed as an external rotor. Figure 2 A control device is provided in the area to the left of the electric motor. This device is used to supply power to the electric motor's stator 4 from an external energy source. When power is supplied to stator 4, its windings are energized, causing the electric motor's rotor 3 to rotate. This rotation of the electric motor's rotor 3 is transmitted to the electric motor's output element 5.

[0037] In electric motor Figure 2 The transmission is arranged on the right side. Figure 2 The transmission shown is designed as a wave gear transmission in this embodiment. Here, the wave gear transmission has an inner sleeve 7, on the outer side of which a toothing is provided. The inner sleeve 7 is designed as a sleeve that is flexible in the circumferential direction. An outer ring 8 is arranged outside the inner sleeve 7, which in this embodiment serves as a torque support component. The outer ring 8 has an internal toothing that can selectively mesh with the external toothing of the inner sleeve 7. Inside the inner sleeve 7, a bushing bearing 6 is arranged in this embodiment. The bushing bearing 6 has an outer ring that is not circular. In particular, the outer ring of the bushing bearing 6 is elliptical. The inner ring of the bushing bearing 6 is coupled to the output element 5 of the electric motor.

[0038] When the electric motor's rotor 3 rotates, the bushing bearing 6 is driven to rotate. Due to the non-circular shape of the outer ring 8 of the bushing bearing 6 and its contact with the inner circumference of the inner sleeve 7, the inner sleeve 7 deforms in a wave motion. As a characteristic feature of the wave gear transmission, the inner sleeve 7 has a smaller number of teeth than the inner toothing of the outer ring 8. Therefore, when the outer ring 8 is stationary and the bushing bearing 6 rotates, the inner sleeve 7 is driven to rotate. Here, the direction of rotation of the inner sleeve 7 is opposite to that of the electric motor's rotor 3.

[0039] Due to the special design of the wave gear transmission, a high transmission ratio of 1:50 or higher can be achieved in a compact design. Therefore, in this application, electric motors with a relatively high rated speed can be used in a compact design. In particular, electric motors with a rated speed of 5000 rpm or higher can be used. The speed, which is reduced due to the transmission ratio, is transmitted to the support element 10 of the wave gear transmission, which is rotatably supported on the housing 1 via a bearing.

[0040] The transmission output element 9 is coupled to a support element 10 provided on the outer ring 8 of the wave gear transmission. The rotation of the support element 10 is transmitted to the transmission output element 9, which is located radially outside the support element 10 of the wave gear transmission. Here, a reaction torque is applied to the outer ring 8, which serves as a torque support component. This reaction torque is then transmitted to the housing 1, which serves as a fixed element.

[0041] A second freewheel 11 is provided on the radial outer circumference of the transmission output element 9. The second freewheel 11 is located between the radial outer circumference of the transmission output element 9 and the radial inner circumference of the output element 14 of the drive. The second freewheel 11 is configured to transmit the rotation of the transmission output element 9 associated with forward travel of the vehicle to the output element 14. Rotation of the transmission output element 9 relative to the output element 14 in a direction opposite to the direction of rotation associated with forward travel is not transmitted to the output element 14.

[0042] Thus, the rotations of the pedal crankshaft 2 and the transmission output element 9 merge at the driven element 14. In this way, the drive device is designed to have a function for combining the muscle force introduced into the pedal crankshaft 2 and the driving force output from the rotor 3 of the electric motor.

[0043] In this embodiment, the driven wheel 15 is configured as a sprocket of a bicycle drive. The driven wheel 15, configured as a sprocket, has a chain (not shown) as a traction mechanism and is mounted on the hub of the bicycle's rear wheel along with a sprocket set (also not shown). In one embodiment, the bicycle has a derailleur transmission that can guide the chain to sprockets with different tooth counts via a rear derailleur. In this embodiment, the rear derailleur is operated by the rider's operating element.

[0044] During vehicle operation, the rider can introduce muscle force into the drive device via the pedal crank shaft 2, which is transmitted to the driven element 14 via the first free wheel 13. At the same time or at least temporarily, the driving force of the electric motor can also be transmitted via the Figure 1 The transmission shown is transmitted to the driven element 14 via the second freewheel 11. When the rider operates the operating element for shifting the chain position in this operating state to change the transmission ratio between the driven wheel 15 (designed as a chain pulley) and the rear wheel, dynamic speed changes occur, and due to the inertia of the components with mass, shocks often occur. Furthermore, during vehicle operation, such as when braking or traveling on significantly uneven terrain, strong vibrations and shocks can occur in the drive train between the driven wheel 15 and the rear wheel of the vehicle.

[0045] In order to take these dependencies into account, the drive has Figure 2 The torque limiting assembly 20 is shown. Figure 2In the embodiment, a torque limiting assembly 20 is provided radially outside the outer ring 8 and radially inside the housing 1, which comprises a friction clutch device 21, a preload element 22a and a bracket 26. Figure 2 In the embodiment of the present invention, the outer ring 8 is fixedly held on the housing 1 by a torque limiting assembly 20, thereby fulfilling the function of serving as a torque support member to accommodate the reaction torque during operation of the drive device. The torque limiting assembly 20 has a spring 22, which is mounted in a bracket 26. The spring 22 according to the present embodiment has multiple spring elements. In particular, the spring 22 is formed by multiple helical compression springs distributed around the spring 22. In alternative embodiments, it is conceivable that the spring 22 can also be composed of a single helical compression spring, a disc spring, etc. The bracket 26 is mounted on the inner circumference of the housing 1. On the other side with respect to the axial direction, a friction clutch facility 21 is provided on the outer circumference of the outer ring 8. The friction clutch facility 21 consists of multiple friction clutch elements that are concentrically arranged around the outer circumference of the outer ring 8.

[0046] These friction clutch elements include a fixed friction clutch element mounted on the housing 1 in a rotationally fixed manner and a movable friction clutch element fastened to the outer circumference of the outer ring 8. The fixed and movable friction clutch elements are alternately stacked. Based on the spring force of the preload element 22, the fixed and movable friction clutch elements of the friction clutch device 21 are pressed together, so that up to a certain torque, the outer ring 8 remains fixed relative to the housing 1. When the maximum design torque is exceeded, slippage occurs on the friction clutch device 21, so that the fixed and movable friction clutch elements of the friction clutch device 21 can rotate relative to each other, and thus the outer ring 8 can rotate relative to the housing 1.

[0047] This ensures that, when the maximum supporting torque is exceeded, the outer ring 8 can rotate relative to the housing 1. This function allows the maximum torque acting on the rotor 3 of the electric motor to be limited.

[0048] Thus, in the event that the supporting torque acting on outer ring 8 exceeds the maximum torque, the torque acting in the force transmission path of the drive device is limited. In particular, overloading of the transmission components of the drive device can be prevented, thereby improving operational safety. To achieve this goal, the torque limiting assembly 20, and in particular the spring force of the preload element 22, is designed in accordance with the requirements for protecting the components used for force transmission in the drive device.

[0049] exist Figure 1 The design concept of the torque support member is shown in FIG. Figure 1 In the middle is the outer ring 8. It should be noted that in an alternative embodiment the torque support member is a separate element connected to the outer ring 8.

[0050] like Figure 1As shown, the outer ring 8 has an axial extension and is designed to be rotationally symmetrical. On the axial side of the outer ring 8 (which is located in the region of the support 26 of the preload element 22), a radially outwardly directed surface section 81 has an outwardly raised profile. The raised profile is designed to be rotationally symmetrical and extends around the outer circumference of the outer ring 8. Figure 1 As shown, the outwardly convex profile has a convex radius R1, which relates to the profile when observing the axial longitudinal section of the outer ring. In addition, on the axial side of the outer ring 8 (which is supported on the radially inwardly protruding section of the housing 1), the radially outwardly pointing surface section 82 has an outwardly convex profile. The convex profile is also designed to be rotationally symmetrical and also extends around the outer circumference of the outer ring 8. Figure 1 As shown, the outwardly bulging profile has a bulging radius R2, which relates to the profile when observing an axial longitudinal section of the outer ring. The bulging radii R1 and R2 are different from each other. In particular, the bulging radius R2 is smaller than the bulging radius R1.

[0051] In addition, surface segments 83 and 84 are provided in the axially opposite end regions of the outer ring 8, which are axially supported on the housing 1 or on the support 26 of the preload element 22. These surface segments 83 and 84 also have an outwardly (i.e., axially) raised profile. The raised profiles on the axially outwardly pointing surface segments 83 and 84 each have a raised radius R3 or R4.

[0052] The raised contours on the corresponding surface sections each form a circumferential projection protruding from the surface. The outer ring 8 engages with the surface sections 81 , 82 , 83 , 84 in the respectively opposite surfaces and is supported accordingly.

[0053] The surface section provided with a raised profile as the contact area for mounting outer ring 8 provides improved freedom in the event of possible manufacturing variations in drive unit components, thereby reducing the likelihood of outer ring 8 seizing, particularly when outer ring 8 is to be rotated due to exceeding the maximum permissible torque on torque limiting assembly 20. This embodiment thus ensures that excessive torque fluctuations, shocks, and strong torques due to the inertia of the entire system are transmitted to rotor 3 of the electric motor only up to the maximum design value. This improves the functionality and durability of the electric motor. Simultaneously, by designing outer ring 8 as a torque-supporting component, functional safety in the drive unit can be improved when the permissible torque is exceeded.

[0054] In this embodiment, the drive device is applied to a bicycle configured as an electric bicycle or an electric-assisted bicycle. In an alternative embodiment, the drive device is applied to a multi-track vehicle, in particular, a vehicle having three or four wheels.

[0055] Reference Signs List

[0056] 1 Housing

[0057] 2 pedal crank axles

[0058] 3 Rotor of the electric motor

[0059] 4 Stator of the electric motor

[0060] 5 Output element of electric motor

[0061] 6 Bushing bearings for harmonic gear transmissions

[0062] 7 Inner sleeve of harmonic gear transmission

[0063] 8 Outer ring (torque support member)

[0064] 9 Transmission output element

[0065] 10 Support components of harmonic gear transmission

[0066] 11 Second Free Wheel

[0067] 12 pedal crankshaft output element

[0068] 13 First Liberty Ship

[0069] 14 Driven element

[0070] 15 driven pulley

[0071] 20 Torque limiting component

[0072] 21 Friction clutch facilities

[0073] 22 Preload element

[0074] 26 bracket

[0075] 81 surface segments

[0076] 82 face segments

[0077] 83 surface segments

[0078] 84 face segments

[0079] R1-R4 ridge radius

Claims

1. A driving device for a vehicle, the driving device having - an electric motor (3, 4) for at least temporarily driving the vehicle by supplying electric power to the electric motor (3, 4); a pedal crankshaft (2), the pedal crankshaft being used to receive muscle force to at least temporarily drive the vehicle by muscle force; and a driven element (14), through which the driving device can output a driving force for driving the vehicle; - a transmission with a predetermined transmission ratio, which is coupled on the input side to the output element (5) of the electric motor (3, 4) and can be coupled on the output side to the output element (14) of the drive device via a transmission output element (9); - a pedal crankshaft output element (12) coupled to the pedal crankshaft (2), the pedal crankshaft output element being coupleable to a driven element (14) of the drive device; The drive device has a torque limiting component (20) configured to limit the torque acting in the force transmission path between the electric motor (3, 4) and the driven element (14), wherein when the torque applied to the torque limiting component (20) exceeds a predetermined maximum torque, the torque support member is allowed to rotate relative to the fixed element of the drive device, thereby limiting the torque acting on the rotor (3) of the electric motor (3, 4) to a permissible torque. Therein, at least one of the axially and radially outwardly pointing surface sections (81; 82; 83; 84) of the torque support component is designed to have an outwardly convex contour.

2. The driving device according to claim 1, characterized in that The torque support member is coupled to a housing (1) of the drive device to support a reaction torque, wherein the torque limiting assembly (20) is provided in a force transmission path between the torque support member and the housing (1) so as to limit the support torque to a predetermined maximum support torque.

3. The driving device according to claim 2, characterized in that When the torque applied to the torque limiting assembly (20) exceeds the predetermined maximum support torque, the torque supporting member of the transmission (3, 4) is allowed to rotate relative to a fixed element, thereby limiting the torque acting on the rotor (3) of the electric motor (3, 4) based on the reaction torque to an allowed torque.

4. A drive device according to any one of the preceding claims, characterized in that The torque limiting assembly (20) has a friction clutch device (21) which is preloaded by a preload element (22) so that when a predetermined maximum torque present on the torque limiting assembly (20) is exceeded, slip occurs in the friction clutch device (21), thereby allowing relative movement between the torque support member and the fixed element via the torque limiting assembly (20).

5. Drive device according to any one of the preceding claims, characterized in that The torque support component is rotationally symmetrical and has on its outer circumference at least one radially outwardly directed surface section (81, 82) which engages with the inner circumference of the fixing element via an outwardly raised contour.

6. Drive device according to any one of the preceding claims, characterized in that The torque support component is rotationally symmetrical and has at least one radially outwardly directed surface section (81) disposed thereon, which engages with a radially inwardly directed surface of a support (26) of a preload element (22) of the torque limiting assembly (20).

7. The driving device according to claim 5 or 6, characterized in that: The torque support component has two surface sections (81, 82) on its outer circumference that are axially spaced apart from one another and point radially outwards.

8. Drive device according to any one of the preceding claims, characterized in that The torque support component extends axially and has at least one axially outwardly directed surface section (83) which engages with a radial section of the fixing element via an outwardly raised contour.

9. Drive device according to any one of the preceding claims, characterized in that The torque support component extends axially and has at least one axially outwardly directed surface section (84) which engages with a radial section of a support (26) of a preload element (22) of the torque limiting assembly (20) via an outwardly raised contour.

10. The driving device according to claim 8 or 9, characterized in that: Two axially outwardly directed surface sections (83, 84) are provided on the torque support component and are arranged on axial end sections of the torque support component.

11. The driving device according to any one of claims 5 to 10, characterized in that The outwardly raised contour of at least one of the surface sections (81, 82, 83, 84) is configured with a predetermined raised radius (R1, R2, R3, R4).

12. The driving device according to claim 11, characterized in that The bulge radius of the outwardly bulging contour of the individual surface segments is designed to have a predetermined bulge radius, wherein at least for the radially outwardly directed surface segments (81, 82) different bulge radii are provided in each case.

13. The driving device according to claim 11 or 12, characterized in that: The predetermined bulging radius is configured such that concentricity deviations between the torque support member and the fixing element can be compensated.

14. Drive device according to any one of the preceding claims, characterized in that The fixing element is designed as a housing (1) of the drive device, and the torque support component has an outer ring (8) of the transmission, with which a reaction torque of the transmission can be introduced into the housing.

15. Drive device according to any one of the preceding claims, characterized in that The transmission is constructed as a harmonic gear transmission having a housing (1) serving as a fixed element, the housing having: an inner sleeve (7) provided with an external toothing and connected to a transmission output element (9); an outer ring (8) provided with an internal toothing, the outer ring being a torque support member of the transmission; and a bushing bearing (6) which can be driven by the electric motor (3, 4) via the input side of the transmission, the bushing bearing being used for fluctuating deformation of the inner sleeve (7), wherein the external toothing of the inner sleeve (7) has a smaller number of teeth than the internal toothing of the outer ring (8), and the fluctuating deformation of the inner sleeve (7) causes the inner sleeve (7) to rotate relative to the outer ring (8).

Images