Drive unit

Abstract

The present invention relates to a drive unit (10) for a human-powered vehicle, in particular for a bicycle or EPAC. The drive unit (10) comprises a housing (12), a bottom bracket shaft (14), an electric auxiliary drive (16), and an output shaft (22) designed as a hollow shaft. The bottom bracket shaft (14) and the output shaft (22) are arranged coaxially with each other. The output shaft (22) partially surrounds the bottom bracket shaft (14) in the axial direction and radially outward. A first freewheel clutch (24) and a second freewheel clutch (26) acting on the output shaft (22) are arranged radially between the bottom bracket shaft (14) and the output shaft (22) and are adjacent to each other in the axial direction.

Description

[Technical field]

[0001] The present invention relates to a drive unit for a human-powered vehicle having the features according to the preamble of claim 1. A human-powered vehicle is in particular a vehicle actuated by muscle power. [Background technology]

[0002] DE 102015100676 A1 discloses a drive assembly having a human drive, an electric auxiliary drive, a strain wave gearing and a common output element, the drive having a complex structure with many individual components and bearing points.

[0003] EP 2 724 926 A1 discloses a central drive unit with a bottom bracket shaft for a human drive and a downstream auxiliary drive with a planetary gear set, which also has a relatively complex structure with many individual components.

[0004] DE 102014108611 A1 discloses a bicycle drive having a drive housing for receiving a bottom bracket shaft and a strain wave gear device arranged inside the drive housing and drivingly connectable with a traction means carrier. This bicycle drive also has a complex structure. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] DE102015100676A1 No. [Patent Document 2] EP2724926A1 issue [Patent Document 3] DE102014108611A1 No. Summary of the Invention [Problem to be solved by the invention]

[0006] The object of the present invention is to provide an improved drive unit compared to the above-mentioned prior art, in particular with regard to optimized packaging and a compact construction. [Means for solving the problem]

[0007] The present invention solves this problem by a drive unit having the features of claim 1, which is configured for a human-powered vehicle, in particular for a bicycle or an EPAC (Electrically Power Assisted Cycle). The drive unit comprises a housing, a bottom bracket shaft, an electric auxiliary drive and an output shaft designed as a substantially cup-shaped hollow shaft. The bottom bracket shaft and the output shaft are arranged coaxially with one another. The output shaft partially surrounds the bottom bracket shaft in the axial direction and radially outwardly. A first freewheel clutch and a second freewheel clutch acting on the output shaft, axially adjacent to one another, are arranged radially between the bottom bracket shaft and the output shaft.

[0008] The coaxial arrangement of components, which is advantageous for a compact construction, allows good utilization of the available construction space, so that the assemblies of the drive unit, such as the electronic unit or electronic circuit board, the electric motor, the gear unit, the output shaft and / or the freewheel clutch, can be arranged centrally around the bottom bracket shaft.

[0009] The freewheel clutches act on the output shaft. They can therefore each be mechanically coupled to the output shaft on the output side, i.e. via the output of the freewheel clutch, for example via an outer ring. The freewheel clutches can be coupled to an inner circumferential surface of the output shaft. This inner circumferential surface can be designed to be continuous in the axial direction, in particular to have a constant diameter. Apart from this, a chain ring or a chain ring carrier can be fixed to the output shaft for coupling with a drive chain.

[0010] The outputs of the freewheel clutches, for example their outer rings, can be non-rotatably connected to the inner circumference of the output shaft, for example by pressing the freewheel clutches in. The freewheel clutches can each comprise an inner ring, an outer ring and a control element located between them, which allows the transmission of torque between the inner ring and the outer ring in only one direction of rotation. The control element can be, for example, a clamp roller, a clamp body, a ratchet, etc.

[0011] The electric auxiliary drive may comprise an electric motor and a transmission unit mechanically coupled thereto, for example a strain wave gear. With the strain wave gear, high transmission ratios can be achieved in a compact design. The strain wave gear may comprise a wave generator, a deformable cylindrical bush with external teeth (Flexspline) and a cylindrical outer bush with internal teeth. The wave generator may be formed as an elliptical disk. The disk has a rolling bearing arranged thereon and an optionally deformable raceway. The Flexspline may be designed in the shape of a ring or a cup. The Flexspline usually serves as the output of the strain wave gear.

[0012] The electric motor can be designed as an external rotor motor, i.e. the rotor of the electric motor can be designed as an external rotor, the rotor radially surrounding the stator, as a result of which an advantageous power density and a compact size can be achieved.

[0013] A stator carrier can be provided, in particular with a sleeve-shaped carrying part and a fixing part, in particular with a disk-shaped part. A stator can be fixed to the stator carrier, in particular to the carrying part, and / or a rotor can be mounted by means of a rolling bearing. Apart from this, an electronic unit, for example an electronic circuit board, can be fixed to the stator carrier, in particular to the fixing part. The stator carrier can be fixed to a housing of a drive unit via the fixing part.

[0014] Advantageously, the first freewheel clutch can couple the bottom bracket shaft with the output shaft. Thus, human driving of the output shaft is possible, for example by actuating the bottom bracket shaft using muscle power. A power flow coupling exists when torque can be transmitted from one component, for example the bottom bracket shaft, to another component, for example the output shaft.

[0015] Advantageously, the second freewheel clutch can couple the power flow between the electric auxiliary drive and the output shaft, thus allowing an electric or auxiliary drive of the output shaft. A power flow coupling exists when torque can be transmitted from one component, for example the bottom bracket shaft, to another component, for example the output shaft.

[0016] Advantageously, the electric auxiliary drive can comprise a strain wave gearing with a flexspline. The flexspline is coupled to the second freewheel clutch, preferably via an annular adapter. An intermediate space between the flexspline and the second freewheel clutch can be radially bridged by the adapter. The output shaft can thus be constructed more simply from a constructional and manufacturing point of view. The adapter can optionally be hardened, which increases the stability of the adapter. As mentioned above, the electric auxiliary drive can comprise an electric motor coupled to a strain wave gearing. The torque of the electric motor can thus be transmitted to the output shaft by means of the strain wave gearing and the adapter.

[0017] Advantageously, the flexspline as output of the strain wave gearing can be provided with a preferably sleeve-shaped coupling part. Via the coupling part, the flexspline and the annular adapter are connected to one another in a connection region. In the connection region, a mating part and / or an adhesive part are formed. This contributes to a precise and stable connection between the flexspline and the adapter. Thus, the mating part between the flexspline and the annular adapter can be formed in a part of the connection region (mating region). The adhesive part can be formed in a further part of the connection region (adhesive region). The mating region and the adhesive region can be separated from one another, for example by a radial shoulder formed on the adapter and / or on the coupling part, respectively. The functional surfaces of the mating region and the adhesive region are thus separated from one another.

[0018] Advantageously, the bottom bracket shaft can comprise a first shaft part and a separate second shaft part, or it can consist of these shaft parts. The shaft parts can be connected to one another in an axially, in particular reversibly. The bottom bracket shaft can therefore be split, for example, in the axial direction. This facilitates installation, since the assembly can simply be mounted inside the cylindrical housing of the drive unit. In the connection region, the shaft parts can comprise an axially protruding collar, which in the connected state radially surrounds the shaft parts on the outside, i.e. the shaft parts overlap one another in the connection region. One shaft part can comprise a plug part and the other shaft part a corresponding socket part.

[0019] Advantageously, the two shaft parts can be fixed to one another by means of a screw connection, preferably arranged centrally. This allows for a structurally simple and stable fixing. The screw connection can be realised by means of only one screw. The central longitudinal axis of the screw can be aligned axially, i.e. parallel to the central longitudinal axis of the bottom bracket shaft, or in particular coaxially oriented. The screw can be inserted through a through-hole in one shaft part, for example the second shaft part, and screwed into an internally threaded hole in the other shaft part, for example the first shaft part.

[0020] Advantageously, the bottom bracket shaft can be rotatably mounted at one end to a housing cover that defines the housing at the front side by means of a first bearing, and / or the bottom bracket shaft can be mounted at the other end to the output shaft by means of a second bearing, thereby providing a reliable and structurally advantageous mounting of the bottom bracket shaft.

[0021] Advantageously, the bottom bracket shaft can be provided with a shaft shoulder protruding radially outward. Via the shaft shoulder, the bottom bracket shaft is connected with the first freewheel clutch. A sensor system for torque detection can be provided. The sensor system detects the torque applied to the bottom bracket shaft at the shaft shoulder, for example at the front side. Regardless of the measurement method used, it is possible to dispense with the classical torque measurement with a sleeve. This therefore results in a constructionally advantageous and at the same time space-saving construction.

[0022] The sensor system for torque detection can be attached to the bottom bracket shaft, for example to the end face of the shaft shoulder and fixed there. The sensor system is thus applied to the measuring point and can rotate with the shaft. Energy can be supplied by sliding contacts or inductively from an electronic unit, for example an electronic circuit board. The signal of the sensor system can be transmitted wirelessly or via sliding contacts to the electronic unit, for example an electronic circuit board.

[0023] Advantageously, the sensor system for torque detection can comprise one or more strain gauges, for example attached to the front side of the shaft shoulder, which allows a reliable detection of torque. The determination of the torque, i.e. the torque applied to the bottom bracket shaft, can be made on the basis of the detected deformation of the shaft shoulder relative to the bottom bracket shaft.

[0024] Alternatively or additionally, the sensor system for torque detection can advantageously comprise one or more magnetostrictive measuring elements mounted on the shaft shoulder, for example on the front side, which also allows the torque to be determined. The determination of the torque, i.e. the torque applied to the bottom bracket shaft, can be made on the basis of the detected shear stresses on the shaft shoulder.

[0025] Advantageously, a sleeve can be provided. The sleeve is pressed or pressed onto the bottom bracket shaft. The sleeve comprises a socket portion for one or more rolling bearings of the flexspline. The one or more rolling bearings can be or are axially fixable in the socket portion. Thus, the bearings of the flexspline can be axially positioned in a constructively simple manner. The one or more rolling bearings are rolling bearings arranged on the output side of the flexspline, for example at the coupling of the flexspline. The socket portion can be formed with, for example, an axially extending through-through for passing electrical lines. Thus, the electronic unit of the drive unit can be simply connected to the sensor system, i.e. to an electronic unit which is part of the sensor system.

[0026] Advantageously, the sealing surface for the sealing position between the bottom bracket shaft and the stator carrier guiding the bottom bracket shaft can be formed by means of a sleeve, so that a reliable separation can be created in the stator carrier, whereby an electronic unit arranged on one side of the stator carrier, for example an electronic circuit board, is separated from mechanical and possibly lubricated components arranged on the other side of the stator carrier, so that the risk of damage to the electronic unit can be reduced.

[0027] Advantageously, the sleeve and the bottom bracket shaft can be sealed by means of a sealing element, for example an O-ring, arranged radially between the bottom bracket shaft and the sleeve, so that radial capillary action between the bottom bracket shaft and the sleeve can be prevented, again reducing the risk of damage to the electronic unit.

[0028] Advantageously, a line guide, for example a channel, can be formed in or within the sleeve, in which electrical lines for power and / or signal transmission between a sensor system for torque detection, for example arranged on the shaft shoulder, and an electronic unit, for example an electronic circuit board arranged on the stator carrier, can be arranged, so that electrical energy and / or signals can be transmitted through the sleeve in a particularly space-saving manner.

[0029] Advantageously, one or more slip rings can be mounted on the sleeve for power and / or signal transmission between the electronic unit and a sensor system for torque detection. Advantageously, the electronic unit, for example an electronic circuit board, can comprise one or more electrical sliding contacts, each of which interacts with a slip ring. This allows for a space-saving and easy-to-mount power and / or signal transmission. A signal of the sensor system can be modulated, for example via radio frequency, to one of the slip rings.

[0030] The invention will now be described with reference to the drawings, in which the same elements or elements having the same function are given the same reference numbers. [Brief description of the drawings]

[0031] [Figure 1] FIG. 2 is a cross-sectional view of an embodiment of a drive unit. [Diagram 2] FIG. 2 is an enlarged partial view of the output shaft and freewheel clutch of the drive unit of FIG. 1; [Diagram 3] FIG. 2 is an enlarged partial view of a flexspline of the strain wave gear device of the drive unit of FIG. 1. [Figure 4] FIG. 2 is a cross-sectional view of the bottom bracket shaft of the drive unit of FIG. 1. [Diagram 5] FIG. 2 is a perspective view of a bottom bracket shaft of the drive unit of FIG. 1; [Figure 6a]FIG. 2 is a front view of the bottom bracket shaft, sleeve, and stator carrier of the drive unit of FIG. 1. [Figure 6b] FIG. 2 is a cross-sectional view of the bottom bracket shaft, sleeve, and stator carrier of the drive unit of FIG. 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] 1 shows a drive unit for a human-powered vehicle, such as a bicycle or an EPAC. The drive unit is generally designated by the reference numeral 10.

[0033] The drive unit 10 comprises a housing 12 in or within which the components of the drive unit 10 are arranged. The drive unit 10 comprises a bottom bracket shaft 14 for human drive by muscle power. The bottom bracket shaft 14 is rotatably mounted in the housing 12 of the drive unit 10. Furthermore, the drive unit 10 comprises an electric auxiliary drive 16 comprising an electric motor 18 and a strain wave gear 20. The drive unit 10 further comprises a substantially cup-shaped output shaft 22 designed as a hollow shaft.

[0034] The bottom bracket shaft 14 and the output shaft 22 are arranged coaxially with respect to one another. The output shaft 22 partially surrounds the bottom bracket shaft 14 in the axial direction and radially outwardly. A first freewheel clutch 24 and a second freewheel clutch 26 acting on the output shaft are arranged radially between the bottom bracket shaft 14 and the output shaft 22 and axially adjacent to one another.

[0035] The freewheel clutches 24, 26 (FIG. 2) act mechanically on the output shaft 22. The freewheel clutches 24, 26 are therefore each connected on the output side, i.e. via the outputs of the freewheel clutches 24, 26, e.g. their outer rings, to the output shaft 22. The freewheel clutches 24, 26 can be connected to an inner circumferential surface 28 of the output shaft 22, as in the example embodiment. The inner circumferential surface 28 can be designed to be axially continuous, in particular to have a constant diameter. A chain ring or a chain ring carrier for connection with a drive chain can be fixed to the output shaft 22 (not shown). The outputs of the freewheel clutches 24, 26, e.g. their outer rings, can be connected non-rotatably to the inner circumferential surface 28 of the output shaft 22, e.g. by pressing in the respective freewheel clutch.

[0036] The auxiliary drive 16 comprises an electric motor 18 and a coupled strain wave gear 20 (FIG. 1). The strain wave gear 20 comprises a wave generator 30, a deformable cylindrical inner bush 32 with external teeth (Flexspline), and a cylindrical outer bush 34 with internal teeth.

[0037] The electric motor 18 comprises a stator 36 with a stator winding 37 and a rotor 38. The electric motor 18 is designed in the example as an external rotor motor, i.e. the rotor 38 of the electric motor 18 is designed as an external rotor. The rotor 38 surrounds the stator 36 radially outwardly.

[0038] A stator carrier 40 is provided, in particular with a sleeve-shaped carrying part 42 and a disk-shaped fixing part 44 (FIGS. 1, 6b). The stator 36 can be fixed to the stator carrier 40, in particular to the carrying part 42, as an example, and / or the rotor 38 can be mounted by means of rolling bearings 46. Apart from this, an electronic unit 48, for example an electronic circuit board, can be fixed to the stator carrier 40, in particular to the fixing part 44. The stator carrier 40 can be fixed to the housing 12 via the fixing part 44.

[0039] A first freewheel clutch 24 connects the bottom bracket shaft 14 to the output shaft 22. As a result, torque can be transmitted by the bottom bracket shaft 14 to the output shaft 22 in the direction of rotation. A second freewheel clutch 26 connects the electric auxiliary drive 16 to the output shaft 22. As a result, torque can be transmitted by the auxiliary drive 16 to the output shaft 22 in the direction of rotation.

[0040] As already mentioned, the electric auxiliary drive 16 comprises a strain wave gear 20 having a flexspline 32. The flexspline 32 is coupled to the second freewheel clutch 26 via a preferably annular adapter 50. The adapter 50 may optionally be hardened.

[0041] The flexspline 32 preferably comprises a sleeve-shaped coupling part 52. Via the coupling part 52, the flexspline 32 and the adapter 50 are connected to one another in a connection region 54 (FIGS. 2 and 3). In the connection region, a mating part 56 and / or an adhesive part 58 are formed. The mating part 56 between the flexspline 32 and the adapter 50 is formed in a part 60 of the connection region 54 (mating part 60). The adhesive part 58 is formed in a further part 62 of the connection region 54 (adhesive part 62). The mating part 60 and the adhesive part 62 can be separated from one another by a radial shoulder 64 formed in the adapter 50 and in the coupling part 52, respectively, as an example.

[0042] The bottom bracket shaft 14 comprises a first shaft portion 66 and a separate second shaft portion 68 (FIG. 4) and is composed of these shaft portions 66, 68. The shaft portions 66, 68 are reversibly connectable to each other. The bottom bracket shaft 14 is therefore axially separable. In the connection region, the second shaft portion 68 is provided with an axially protruding collar 70. In the connected state, the collar 70 radially surrounds the first shaft portion 66 on the outside. In the connected state, the shaft portions 66, 68 therefore overlap each other in the connection region.

[0043] The two shaft portions 66, 68 can be fixed to one another by means of a preferably centrally located threaded connection 72. The threaded connection 72 can be realized by means of only one screw 74. The central longitudinal axis of the screw 74 is axially aligned, i.e. oriented parallel to or, in particular, coaxially with the central longitudinal axis of the bottom bracket shaft 14. The screw 74 can be inserted through a through hole in the second shaft portion 68 and screwed into an internally threaded hole 76 in the first shaft portion 66.

[0044] One end of the bottom bracket shaft 14 is rotatably attached, via a first bearing 78 (FIG. 1), to a housing cover 80 that defines the front side of the housing 12. Furthermore, the other end of the bottom bracket shaft 14 is rotatably attached to the output shaft 22 via a second bearing 82. Next, a third bearing 84 and a fourth bearing 86 are rotatably attached to the output shaft 22.

[0045] The bottom bracket shaft 14 has a shaft shoulder 88 that projects radially outward (Figures 1 and 2). Via the shaft shoulder 88 the bottom bracket shaft 14 is connected to the first freewheel clutch 24. A sensor system 92 for torque detection is provided (Figures 2 and 6b). The sensor system 92 detects the torque applied to the bottom bracket shaft 14 at the shaft shoulder 88, in particular at the front side, i.e. at the end face 90 of the shaft shoulder 88.

[0046] A sensor system 92 for torque detection can be attached and fixed to the bottom bracket shaft 14, for example to an end face 90 of the shaft shoulder 88. The sensor system 92 is thus applied to the measurement point, i.e. the end face 90 of the shaft shoulder 88, and can rotate together with the bottom bracket shaft 14.

[0047] The sensor system 92 for detecting torque may include one or more strain gauges (not shown) attached at the front to the shaft shoulder 88. A determination of torque may be made based on the detected deformation of the shaft shoulder 88 relative to the bottom bracket shaft 14.

[0048] Alternatively or supplementarily, the sensor system 92 for torque detection may comprise one or more magnetostrictive measuring elements 94 attached to the front side, i.e. end face 90, of the shaft shoulder 88. A torque determination may be made based on the detected shear stress in the shaft shoulder 88.

[0049] The drive unit 10 comprises a sleeve 96, which is pressed or pressed onto the bottom bracket shaft 14 (Figures 3 and 6b). The sleeve 96 comprises a socket part 98 for one or more rolling bearings 100, 102 of the flexspline 32. The one or more rolling bearings 100, 102 are axially fixable or fixed in the socket part 98. The rolling bearings 100, 102 attach the flexspline 32 to the coupling part 52. The socket part 98 is formed with an axially extending through-hole 87 for passing an electrical line 89. The line 89 connects the electronic unit 48 of the drive unit 10 with an electronic unit which is part of the sensor system 92 (not shown).

[0050] A sealing surface 104 for the sealing position between the bottom bracket shaft 14 and the stator carrier 40 which guides the bottom bracket shaft 14 is formed by means of the sleeve 96 .

[0051] The sleeve 96 and bottom bracket shaft 14 are sealed using a sealing element 106 , such as an O-ring 106 , disposed radially between the bottom bracket shaft 14 and the sleeve 96 .

[0052] Advantageously, a line guide, for example a channel, can be formed in or within the sleeve 96 (not shown), in which electrical lines 89 for power and / or signal transmission between the sensor system 92 for torque detection and the electronic unit 48 can be arranged (not shown).

[0053] For power and / or signal transmission between the electronic unit 48, in particular the electronic circuit board, and the sensor system 92 for torque detection, one or more slip rings 108, 110 (FIGS. 6a, 6b) are mounted on the sleeve 96. The electronic unit 48, e.g. the electronic circuit board, comprises one or more electrical sliding contacts 112, 114 which interact with the slip rings 108, 110, respectively. [Explanation of symbols]

[0054] 10 Drive unit 12. Housing 14 Bottom bracket shaft 16 Auxiliary drives, electrical 18 Electric Motor 20 Strain Wave Gearing 22 Output shaft 24 No. 1 freewheel clutch 26 Second freewheel clutch 28 Inner surface 30 Wave Generator 32 Deformable inner bush, flexspline 34 Outer bush 36 Stator 37 Stator Winding 38 Rotor 40 Stator carrier 42 Supporting part 44 Fixed part 46 Rolling bearings 48 Electronic unit, circuit board 50 Adapter 52 Joint part 54 Connection Area 56 Mating part 58 Adhesive part 60 Mating Area 62 Adhesive area 64 Radial shoulder 66 First shaft part 68 Second shaft part 70 Protruding Color 72 Threaded Connection 74 Screw 76 holes 78 No. 1 bearing 80 Housing cover 82 No. 2 bearing 84 3rd bearing 86 4th bearing 87 Penetration 88 Shaft Shoulder 89 Electrical Line 90 End face 92 Sensor System 94 Magnetostrictive Measuring Elements 96 Sleeve 98 Socket part 100 Rolling bearings 102 Rolling bearings 104 Sealing surface 106 Sealing element 108 Slip Ring 110 Slip ring 112 Sliding contact 114 Sliding contact

Claims

1. A drive unit (10) for a human-powered vehicle, the drive unit (10) having a housing (12), a bottom bracket shaft (14), an electric auxiliary drive (16) and an output shaft (22) designed as a hollow shaft, the bottom bracket shaft (14) and the output shaft (22) being arranged coaxially with one another and the output shaft (22) partially and radially surrounding the bottom bracket shaft (14) in the axial direction, a first freewheel clutch (24) and a second freewheel clutch (26) acting on the output shaft (22) axially adjacent to one another in the drive unit (10) are arranged radially between the bottom bracket shaft (14) and the output shaft (22), the first freewheel clutch (24) connects the bottom bracket shaft (14) to the output shaft (22), and the second freewheel clutch (26) connects the electric auxiliary drive (16) to the output shaft (22); The electric auxiliary drive (16) comprises a strain wave gear device (20) having a flexspline (32); 1. A drive unit (10), comprising: a sleeve (96) which is pressed or pressed onto the bottom bracket shaft (14), the sleeve (96) comprising a socket portion (98) for one or more rolling bearings (100, 102) of the flexspline (32), the one or more rolling bearings (100, 102) being axially fixable or fixed in the socket portion (98).

2. 2. The drive unit (10) of claim 1, wherein the flexspline (32) is coupled to the second freewheel clutch (26) via an annular adapter (50).

3. 3. The drive unit (10) according to claim 2, characterized in that the flexspline (32) comprises a coupling portion (52), via which the flexspline (32) and the adapter (50) are connected to each other in a connection region (54), and in which a mating portion (56) and / or an adhesive portion (58) are formed.

4. The drive unit (10) according to any one of claims 1 to 3, characterized in that the bottom bracket shaft (14) comprises a first shaft portion (66) and a separate second shaft portion (68), the first shaft portion (66) and the second shaft portion (68) being interconnectable.

5. 5. The drive unit (10) according to claim 4, characterized in that the two shaft portions (66, 68) are fixable or fixed to one another by means of a radially centrally arranged screw connection (72).

6. The drive unit (10) according to any one of claims 1 to 5, characterized in that the bottom bracket shaft (14) is rotatably attached to a housing cover (80) that defines the housing (12) using a first bearing (78), and the bottom bracket shaft (14) is attached to the output shaft (22) using a second bearing (82).

7. 7. The drive unit (10) according to claim 1, wherein the bottom bracket shaft (14) has a shaft shoulder (88) protruding radially outward, the shaft shoulder (88) being connected to the first freewheel clutch (24), and a sensor system (92) for torque detection is provided, the sensor system (92) detecting the torque applied to the bottom bracket shaft (14) at the shaft shoulder (88).

8. 8. The drive unit (10) according to claim 7, characterized in that the sensor system (92) for torque detection comprises one or more strain gauges or one or more magnetostrictive measuring elements (94).

9. 2. The drive unit (10) of claim 1, characterized in that a sealing surface (104) for a sealing position between the bottom bracket shaft (14) and a stator carrier (40) guiding the bottom bracket shaft (14) is formed by means of the sleeve (96).

10. 10. The drive unit (10) according to claim 1 or 9, characterized in that a line guide is formed in or within the sleeve (96), in which electrical lines (89) for power and / or signal transmission between a sensor system for torque detection and an electronic unit (48) can be arranged, and / or one or more slip rings (108, 110) are attached to the sleeve (96) for power and / or signal transmission between the electronic unit (48) and a sensor system for torque detection.

Images