EP2560863A1

EP2560863A1 - Motor-gear unit

Info

Publication number: EP2560863A1
Application number: EP11715248A
Authority: EP
Inventors: Florian Loeffl; Andreas Felsl
Original assignee: B-Labs AG
Current assignee: Joy Industrial Co Ltd
Priority date: 2010-04-20
Filing date: 2011-04-20
Publication date: 2013-02-27
Also published as: JP2013527821A; JP6143671B2; DE102010017829A1; CN103153772A; WO2011131725A1; US20130162112A1

Abstract

What is disclosed is a motor-gear unit for a bicycle which is directly fastened to or flanged on a bottom bracket shell (1), in particular a standard bottom bracket shell. Here, the bottom bracket shell is arranged between the motor-gear unit and a chainwheel. A frame-mounted part - in particular housing - of the motor-gear unit can be fastened to or flanged on the standard bottom bracket shell using an international standard chain guide mount (ISCG).

Description

description

Motor-gearbox unit

The invention relates to a motor-gear unit for a bicycle according to the preamble of claim 1 and a drive unit of a bicycle.

In such engine-gear units, various approaches to their fastening are known.

DE 20 2008 001 881 U1 shows an auxiliary drive for a bicycle, wherein a motor and a transmission are mounted separately from each other at different locations of the frame.

DE 697 29 61 1 T2 shows an auxiliary drive for a bicycle, in which a bottom bracket is arranged together with a motor and a transmission in a housing. Such a motor-gear unit can not be attached to an existing bottom bracket of the corresponding bicycle, but the bottom bracket must be made with the motor-gear unit and mounted on the frame of the bicycle. This disadvantage is given especially when retrofitting a bike with already mounted bottom bracket.

On the other hand, the object of the invention is to provide a motor-gear unit in which a particularly simple installation on a bicycle or on its standard parts is possible.

This object is achieved by a motor-gear unit according to claim 1 or by a drive unit for a bicycle according to claim 25.

The motor-gear unit according to the invention is designed for a, preferably direct, attachment to a frame-fixed bottom bracket, in particular standard bottom bracket, a bicycle. The bottom bracket shell is between the engine-transmission unit and a chainring arranged. This is one

Assembling or retrofitting the engine-gear unit to a bicycle with

Bottom bracket housing, in particular standard bottom bracket, possible without this needs to be rebuilt or replaced. Furthermore, it is advantageous that no further attachment or receiving points for the motor-gear unit according to the invention are necessary on the frame.

The motor-gear unit according to the invention is thus designed for attachment to a side facing away from at least one chainring of a bicycle side of the pedal bearing housing, in particular the standard bottom bracket of the bicycle.

The invention thus preferably relates to standard bottom bracket, but also covers different bottom bracket.

Further advantageous embodiments of the invention are described in the dependent claims.

It is preferred if - in a viewing direction in the direction of travel of the bicycle - the engine-transmission unit is arranged on the left and the chainring to the right of the bottom bracket.

In a preferred embodiment, the motor-gear unit is attached or flanged on its housing on the bottom bracket shell.

In a preferred embodiment, the motor-gear unit is designed for mounting in accordance with the now widely used International Standard Chain Guide Mount (ISCG) on the standard bottom bracket. Preferably, the engine of the unit according to the invention is an electric motor.

This does not cause emissions on the bike and is quiet. The electric motor may be an external rotor whose rotor comprises a stator. For a comparatively high torque can be generated. Or the electric motor may be an internal rotor whose stator comprises a rotor. For a comparatively good heat dissipation can be realized.

The motor of the unit according to the invention may be an electronically commutated three-phase brushless synchronous motor.

The motor of the unit according to the invention also be a particularly flat-build pancake or a permanent magnet synchronous motor (PMSM).

A preferred development of the motor-gear unit according to the invention has a torque sensor for detecting a torque of a drivable by a driver and / or the engine of the unit according to the invention crankshaft.

Preferably, an engine torque may be transmitted to the crankshaft by the motor of the unit according to the invention in dependence on the torque detected by the torque sensor. This engine torque may be assistive or alone acting on the crankshaft.

A particularly finely tuned supplementation or addition of engine torque to the torque applied by the driver is possible if the engine torque can also be regulated during one revolution of the crankshaft as a function of its torque applied by the driver. This can be equalized fluctuations or systematic irregularities of the torque applied by the driver.

A particularly finely controlled addition or addition of engine torque to the torque applied by the driver is also possible if the engine torque can be regulated as a function of a rotational angle of the crankshaft. Thus, systematic irregularities due to the different efficiency of the cranks can be equalized. Since usually the rotational speed of the electric motor is greater than that of the crankshaft of the bicycle, it is preferred if the transmission is a reduction gear. In a first preferred variant, the reduction gear is a cycloidal gear.

To compensate for eccentric masses and to produce a uniform concentricity, it is preferred if the cycloidal gear has two mutually offset cycloidal disks and correspondingly two staggered eccentric.

In a particularly preferred embodiment of the cycloidal drive, its drive block toothing is formed on the ring gear and fixed on the ring gear on the housing and not rotating, while a plurality of bolts of the cycloidal gear can be driven via at least one cycloidal disc.

In another particularly preferred embodiment of the cycloidal drive, its bolts are fixed to the housing and are not rotating, while the ring gear can be driven via its drive shaft toothing and via the at least one cycloidal disk.

In a second preferred variant, the reduction gear is a single-stage or multi-level planetary gear.

In a third preferred variant, the reduction gear is a harmonic drive gear, in particular a Gleitkeilgetriebe or stress wave gear.

It is preferred if the reduction gear has a reduction of at least 3/1. Preferably, a freewheel of the crankshaft relative to the engine of the unit according to the invention or a - preferably automatically activated - clutch, provided between the crankshaft and the engine, so that the driver without Support can drive or drive, without having to turn it the unit.

Preferably, a bottom bracket is integrated in or on the motor-gear unit according to the invention.

In a second preferred embodiment, the standard bottom bracket shell can conform to International Standard for Bottom Bracket Shells (BB30). This bearings can be omitted.

The drive unit according to the invention is provided for a bicycle and has a bottom bracket shell, in particular a standard bottom bracket shell. On a first side of the bottom bracket, a motor-gear unit described above is attached, while on a second - the first side opposite - side of the bottom bracket one or more chainrings are arranged. As a result, an assembly or retrofitting of the motor-gear unit on a bicycle with bottom bracket, in particular standard bearing frame, possible without this needs to be rebuilt or replaced. A further advantage is that no further mounting or receiving points for the engine-transmission unit according to the invention on the frame of the bicycle are necessary.

The invention thus preferably relates to standard bottom bracket, but also covers different bottom bracket. In the following, with reference to the figures, various embodiments of

Invention described in detail. Show it:

Figure 1 shows a first embodiment of a motor-gear unit according to the invention in a sectional view.

Figure 2 shows a second embodiment of the motor-gear unit according to the invention in a view. Figure 3 shows the second embodiment of the motor-gear unit according to the invention in a sectional view.

4 shows an electric motor of a third embodiment of the motor-gear unit according to the invention in a schematic perspective view.

Figure 5 shows a detail of a stator of the electric motor according to Figure 4 in a schematic view. FIG. 1 shows a first exemplary embodiment of an engine

Gear unit in a cut view. Your case 4 is over a

Connection, which corresponds to the International Standard Chain Guide Mount (ISCG), attached to a bottom bracket shell 1. The bottom bracket shell 1 and the housing 4 are penetrated by a crankshaft 34, at the end portions (not shown) cranks are mounted.

The crankshaft 34 is mounted in the bottom bracket shell 1 via bottom brackets, of which only one bottom bracket 32 is shown in the figure. In the housing 4, an electric motor is arranged in the lower region (in FIG. 1), which is designed as an external rotor. On the side facing away from the bottom bracket 1 of the electric motor (in the figure 1 above), a reduction gear is arranged, which is designed as a cycloidal gear. The electric motor has a stator holder 3 fastened to the housing 4 or to the bottom bracket 1, which carries a stator 2, on whose outer circumference a multiplicity (for example 28) of permanent magnets are arranged. Of the permanent magnets only two opposing permanent magnets 14a, 14b are shown in the figure. These are attached to a rotor 13, which rotates during operation of the electric motor together with the permanent magnets 14a, 14b. On the rotor 13, two eccentric discs or eccentric 17a, 17b are fixed, whose eccentricity or eccentricity are opposite to each other. Thus, the upper eccentric 17a (in FIG. 1) is displaced to the left (in FIG. 1), while the lower eccentric 17b is displaced towards the right. On the outer circumference of each eccentric 17a, 17b, a cycloidal disk 15a, 15b which surrounds the eccentric 17a, 17b is arranged and mounted on the eccentric 17a, 17b via a respective bearing. On the outer periphery of the two cycloidal disks 15a, 15b, a plurality of projections and recesses are uniformly distributed, so that a uniform waveform is formed on the respective outer periphery of the two cycloidal disks 15a, 15b. On the inner circumference of the housing 4 comparable projections and recesses are formed. In this case, the number of projections formed on the cycloidal disks 15a, 15b is 1 less than the number of recesses formed on the housing 4.

In operation of the first embodiment of the motor-gear unit according to the invention, the two eccentrics 17a, 17b are driven by the electric motor with comparatively high speed, wherein the two cycloidal disks 15a, 15b circumferentially about their projections formed on the outer circumference around the recesses formed on the inner circumference of the housing 4 plunge. As a result, the cycloidal disks 15a, 15b perform a comparatively slow rotation. A plurality of driving pins, of which only four driving pins 16a-d are shown in the figure, are received in corresponding passage recesses of the cycloidal disks 15a, 15b, of which only two through-holes are shown in the figure. The driving pins 16a-d and the recesses are arranged on a circular path, wherein the diameter of the driving pins 16a-d are smaller than the diameter of the recesses. Thus, the rotation of the cycloidal disk 15a, 15b is transmitted via their recesses and via the driving pins 16a-d to a driver 28, which is non-rotatably connected to the crankshaft 34. Thus, the double cycloidal disk transmission shown forms a reduction gear that reduces the comparatively high rotational speed of the rotor 13 into the comparatively low rotational speed of the crankshaft 34.

The motor-gear unit according to the invention is arranged largely rotationally symmetrical to the crankshaft 34 and attached to the above-described bottom bracket 1 housing with ISCG recording.

Figure 2 shows a drive unit with a second embodiment of the motor-gear unit according to the invention in a view. A housing 104 of the engine Transmission unit is attached to a bottom bracket shell 101 via a connection conforming to the International Standard Chain Guide Mount (ISCG). The housing 104, together with an output cover 128 encapsulates the entire engine-transmission unit. The bottom bracket shell 101, the housing 104 and the output cover 128 are penetrated by a crankshaft 134, to whose (in Figure 2 upper and lower) end portions (not shown) cranks are attached.

Figure 3 shows the drive unit with the second embodiment of the engine-transmission unit according to the invention in a sectional view The crankshaft 134 is mounted in the bottom bracket housing 101 via two bottom bracket, of which only one bottom bracket 132 is shown in the figure.

In the housing 104, an electric motor is arranged, which is designed as an internal rotor. It has a stator 102 which is fixed to the housing 104. The electric motor further has a rotor 1 13, are arranged on the outer circumference of permanent magnets, of which in Figure 3, only two opposing permanent magnets 1 14a, 1 14b are shown.

At the side facing away from the bottom bracket shell 101 of the electric motor (in Figure 3 above) a cycloidal gear is arranged. Its output to the crankshaft 134 via the slowly rotating output cover 128. Between the output cover 128 and a radial step of the crankshaft 134, a thrust washer is used. The output cover 128 is connected to a clutch encoder 136 via a trapezoidal thread such that the clutch encoder 136 is pushed onto a coupling cone 130 when the electric motor drives in the drive direction. The clutch 103, 136 is released when the electric motor is not driving and it is actively opened when the electric motor briefly turns backwards. The coupling cone 130 is rotatably connected to the crankshaft 134. Between the clutch encoder 136 and a non-rotating portion of the housing 104, a rotational reference 142 with two O-rings 142a, 142b is arranged. The rotor 1 13 is mounted on the portion of the housing 104 via a rotor bearing 144. On the rotor 1 13 two eccentric discs or eccentric 1 17a, 1 17b of the cycloidal gear are fixed, whose eccentricity or eccentricity are opposite to each other. Thus, the upper eccentric 1 17a is offset to the right, while the lower eccentric 1 17b is offset to the left to the left (each in the illustration of Figure 3). On the outer circumference of each eccentric 1 17a, 1 17b, a cycloid disc 1 15a, 15b which comprises the eccentric member 17a, 17b is arranged and mounted on the eccentric member 17a, 17b via a respective cycloidal disc bearing 11a, 19b. Between each cycloidal disk 15a, 15b and the output cover 128, a rack and pinion toothing is provided. For this purpose, a plurality of projections and recesses are evenly distributed on the outer circumference of the respective cycloidal disk 15a, 15b, so that a uniform waveform is formed on the respective outer circumference of the cycloidal disk 15a, 15b. On the inner circumference of the housing 104 comparable projections and recesses are formed. In this case, the number of projections formed on the cycloidal disks 15a, 15b is smaller by one than the number of recesses formed on the housing 104. Uniformly fixed to the circumference of the stator 102 and rotatably held driving pins, of which only two driving pins 16a, 16b are shown in FIG. 1, are received in corresponding passage recesses of the cycloidal disks 15a, 15b, of which only two are shown in FIG Through holes are shown. The driving pins 16a, 16b and the recesses are arranged on a circular path, wherein the diameter of the driving pins 16a, 16b are smaller than the diameters of the recesses.

In operation of the second embodiment of the motor-gear unit according to the invention, the two eccentrics 1 17a, 17b are driven by the electric motor with comparatively high speed, wherein the two cycloidal discs 15a, 15b are circumferentially formed around their projections formed on the outer circumference Immerse the inner circumference of the housing 104 formed recesses. Thus, output cover 128 is driven relatively slowly by the cycloidal disks 15a, 15b. The output cover 128 can be rotatably connected to the crankshaft 134 via the clutch 130, 136. Thus, even in the second embodiment, the double cycloidal disc transmission from a reduction gear, which sets the comparatively high speed of the rotor 1 13 in the relatively low speed of the crankshaft 134. A shaft seal 138 tolerates a non-activated drive the crankshaft 134 via the engine-gear unit, a speed difference between the stationary output cover 128 and the rotating crankshaft 134, while activated drive a shaft seal 140 despite speed difference between the stationary housing 104 and the rotating output cover 128th seals these two housing parts.

Also, the second embodiment of the motor-gear unit according to the invention is arranged substantially rotationally symmetrical to the crankshaft 134 and secured to the above-described bottom bracket 101 with ISCG recording.

Figure 4 shows an electric motor of a third embodiment of the motor-gear unit according to the invention in a schematic perspective view. The electric motor is particularly space-saving in the axial direction and can be provided instead of the electric motors according to FIG. 1 or according to FIG.

On a disc-shaped rotor 213 a plurality of permanent magnets 246 is arranged in a steric manner, of which only the end faces on the outer circumference of the rotor 213 can be seen in FIG. Spaced apart from the permanent magnets (in FIG. 4 via the permanent magnet 246), a multiplicity of coils 248 is arranged in the form of a star, of which only the end sides on the outer circumference of a housing-fixed stator 202 can be seen in FIG.

FIG. 5 shows a section of the stator 202 of the electric motor according to FIG. 4 with the multiplicity of coils 248 in a schematic view.

Notwithstanding the exemplary embodiments shown, the motor-gear unit according to the invention can also be provided in a handbike driven by the arm force of a handbik, wherein hand cranks are attached to the end sections of the crankshaft 34.

Disclosed is a motor-gear unit for a bicycle, directly to a bottom bracket shell, in particular standard bottom bracket shell, attached or flanged is. The standard bottom bracket shell is located between the engine-gearbox unit and a chainring.

A frame-fixed part - in particular housing - the motor-gear unit can be fixed or flanged to the standard bottom bracket shell according to the International Standard Chain Guide Mount (ISCG).

LIST OF REFERENCES

1; 101 bottom bracket housing

2; 102; 202 stator

3 stator holder

4; 104 housing

13; 113; 213 rotor

14a, 14b; 114a, 114b permanent magnet

15a, 15b; 115a, 115b cycloid disk

16a, 16b, 16c, 16d; 116a, 116b driving pin

17a, 17b; 117 eccentric

28 drivers

32; 132 bottom bracket

33 pawl

34; 134 crankshaft

118a, 118b drive train toothing

119a, 119b Cycloid disk bearings

128 output cover

130 coupling cone

136 Clutch transmitter

138 shaft seal

140 shaft seal

142 Rotation reference

142a, 142b O-ring

144 rotor bearings

246 permanent magnet

248 coil

Claims

claims

Motor-gear unit for a bicycle that attaches to a

Bottom bracket, in particular standard bottom bracket shell (1, 101) is designed, characterized in that the bottom bracket shell (1, 101) is arranged between the motor-gear unit and a chainring.

Motor-gear unit according to claim 1, which is fastened via a housing (4; 104) to the bottom bracket shell, in particular standard bottom bracket shell (1; 101).

Motor-gear unit according to claim 1 or 2, which is designed for mounting according to the International Standard Chain Guide Mount (ISCG) on the standard bottom bracket shell (1; 101).

Motor-gear unit according to one of the preceding claims, whose motor is an electric motor (2, 13, 102, 13).

Motor-gear unit according to claim 4, wherein the electric motor (2, 13) is an external rotor whose rotor (13) comprises a stator (2), or wherein the electric motor is an internal rotor whose stator (102) comprises a rotor (1 13).

Motor-gear unit according to one of the preceding claims, whose motor is an electronically commutated three-phase brushless synchronous motor.

Motor-gear unit according to one of claims 1 to 4, whose motor is a pancake rotor whose rotor (213) axially adjacent to a stator (202).

is arranged.

Motor-gear unit according to one of claims 1 to 4, whose motor is a permanent magnet synchronous motor (PMSM).

9. A motor-gear unit according to one of the preceding claims with a torque sensor for detecting a torque of a drivable by a driver and / or by the engine crankshaft (34; 134).

10. The engine-transmission unit according to claim 9, wherein an engine torque in dependence on the torque to the crankshaft (34, 134) is transferable.

1 1. The engine-transmission unit of claim 10, wherein the engine torque

during one revolution of the crankshaft (34; 134) is adjustable.

12. Engine-transmission unit according to claim 10, wherein the engine torque in dependence on a rotation angle of the crankshaft (34; 134) is controllable.

13. Engine-transmission unit according to one of the preceding claims, wherein the transmission is a reduction gear.

14. A motor-gear unit according to claim 13, wherein the reduction gear is a cycloidal gear (15a, 15b, 16a, 16b, 16c, 16d, 17a, 17b, 28; 1 15a, 15b, 16a, 16b, 17, 128).

A motor-gear unit according to claim 14, wherein said cycloidal gear (15a, 15b, 16a, 16b, 16c, 16d, 17a, 17b, 28; 1 15a, 15b, 16a, 16b, 17, 128). two staggered cycloidal discs (15a, 15b, 15a, 15b) and two staggered eccentrics (17a, 17b, 11).

16 motor-gear unit according to claim 14 or 15, wherein a drive gear teeth of the cycloidal gear is arranged in a ring gear and fixed to the housing, and wherein bolts (16a, 16b, 16c, 16d) of the cycloidal gear can be driven.

17. Motor-gear unit according to claim 14 or 15, wherein bolts (1 16a, 1 16b) of the cycloidal gear are fixed to the housing, and wherein a ring gear on a rack and pinion (1 18a, 1 18b) of the cycloidal gear is driven.

18. engine-transmission unit according to claim 13, wherein the reduction gear is a single-stage or multi-stage planetary gear. 19. The engine-transmission unit of claim 13, wherein the reduction gear is a harmonic drive transmission.

20. The engine-transmission unit according to claim 13, wherein the reduction gear has a reduction of at least 3/1.

21. Engine-gear unit according to one of the preceding claims with a freewheel of the crankshaft relative to the engine.

22. Engine-transmission unit according to one of claims 1 to 20 with a clutch (130, 136), which is arranged in the power flow between the engine and the crankshaft (134).

23. Motor-gear unit according to one of the preceding claims with an integrated bottom bracket (32, 132).

A motor-gear unit according to any one of the preceding claims, wherein the standard bottom bracket shell (1; 101) conforms to International Standard for Bottom Bracket Shells (BB30). 25. Drive unit for a bicycle with a bottom bracket shell, in particular

A standard bottom bracket shell (1; 101) on the first side of which is mounted a motor-gear unit according to any one of the preceding claims and on the second side of which a chainring is arranged.