DE202017006777U1 - Drive unit for a bicycle - Google Patents

Abstract

Drive unit (10) for a bicycle having a housing (11) forming a wet space (26/15) filled with a lubricant, - having a shaft (13) rotatably supported by the housing (11), by means of which a first Torque is introduced, - with an in the housing coaxially around the shaft (13) arranged around the electric motor (16), by means of which a second torque is introduced, - with a in the output member (33/34), which of the addition of the first and the second Torque is used - with an at least single-stage, in the housing (11) arranged gear (27), which in the power flow between the electric motor (16) and output member (33/34) is arranged, - with a between motor (16) and shaft (13 ), which measured values of the shaft (13), such as torque and / or speed detected, characterized in that- the housing (11) along radial parting planes (R) is divided into three housing parts, - in the housing (11) additional, dry room (42) is provided, in which electronic components, in particular the control electronics for the electric motor (16) are arranged.

Description

The invention relates to a drive unit for a bicycle with a housing which forms a wet, filled with a lubricant space, with a shaft, rotatably mounted from the housing, by means of which a first torque is introduced, with a coaxially disposed in the housing around the shaft electric motor , By means of which a second torque is introduced, with a in the output member, which serves to add the first and second torque, with an at least one-stage, arranged in the housing gear, which is arranged in the power flow between the electric motor and driven member, with a between engine and Wave arranged sensor unit, which measured values of the shaft, such as torque and / or speed detected.

Such drive units for bicycles for electromotive assistance in locomotion are well known from the prior art. They can be part of the front wheel or the rear wheel. In addition, there are solutions in which the drive is arranged in the region of the bottom bracket or the front chainring of the bicycle and acts by means of the front chainring drive-supporting. The latter drive units are often referred to as a mid-engine, since they are arranged approximately centrally on the frame between the front wheel and the rear wheel.

From the applicant's own DE 10 2014 117 137 B4 For example, a drive unit for an electric motor assisted bike shows. The embodiment here shows a so-called hub drive, in which in an enlarged diameter wheel hub an electric motor is housed together with transmission and control unit. In this drive, it is provided that the drive force provided by the cyclist via the crank drive is combined with the drive force provided by the electric motor within the wheel hub of the rear wheel and acts on the rear wheel to promote drive. The electric motor and the likewise provided gear are arranged concentrically to the wheel axle and to the axis of rotation of the wheel or coaxially around the wheel axle.

From the DE 10 2009 014 246 A1 is known a drive unit for electric motor-assisted bicycles, which acts on the front sprocket. Again, a coaxially arranged around the pedal crankshaft around electric motor with transmission gears is provided. The driving force exerted by the pedal on the front chainring and the driving force provided by the electric motor are combined within the crankshaft housing.

Technically similar is also disclosed DE 10 2013 108 549 B4 , which also shows different embodiments with alternative central motor arrangements.

The object of the invention is to provide an improved drive unit with a compact design.

The invention is achieved by a drive unit with the features of claim 1, in particular with its characterizing features, according to which an additional, dry space is provided, in which electronic components, in particular the control electronics for the electric motor are arranged.

By creating a second, lubricant-free, dry space, the invention ensures a further integration of components in the drive unit, in particular the integration of electronic components, which serves to control the electric motor and the adjustment of the output power to the respective driving situation. Such a high degree of integration simplifies the assembly of a bicycle, because the drive unit comprises all essential components and only in a designated holder, for example, a correspondingly shaped hub or a correspondingly shaped bottom bracket has to be used. The assembly personnel are not subject to high demands with regard to the handling of electronic components. Separate operations for mounting electronic components eliminated.

Maintenance is greatly simplified if, according to a preferred embodiment, the dry space is formed concentrically around the shaft and in particular has an axially facing opening closable with a lid.

It is furthermore provided that the housing forms a sleeve-like indentation arranged concentrically around the shaft, which delimits an annular space arranged between the shaft and the electric motor.

The sleeve-like indentation is against rotation of the shaft, so that for various sensors, such as speed sensors, a fixed reference point for a measurement is available and both rotating and stationary to be arranged sensors can be used. Particularly preferred is the application of a torque sensor in the region of the sleeve-like feeder. In addition, no separate components are needed because the sleeve-like feeder is part of the housing of the drive unit.

It is envisaged that the housing is constructed in several parts by at least one radial parting plane. With these features essential to the invention, it is ensured that the housing can be assembled from individual parts that can be produced without undercut. This is particularly advantageous if at least parts of the housing are produced by casting.

It is further provided that the annulus is separated axially relative to the adjacent wet space.

In this way, a second, in doubt dry, so lubricant-free space can be provided, provided that the sensor units used, which are to be arranged within the annular space, so require.

It is further provided that the rotor of the electric motor is arranged around the outside of the sleeve-like housing feeder. Conversely, this means that the annulus for the sensor is disposed within a recess of the rotor of the electric motor and thus a space-optimized arrangement of the sensor units and the space provided for this purpose is possible. The axially necessary length of the drive unit is thus reduced.

It is further provided that a transmission input member is mounted concentrically and rotate stored on the shaft and that the rotor of the electric motor is mounted on the transmission input member and by means of this on the shaft.

The main advantage of this feature of the invention is the fact that the rotor requires no separate storage relative to the shaft or the sleeve-like housing catch. As a result, space is gained.

It is further provided that the transmission input member is mounted axially displaceably on the shaft.

The axial displaceability of the transmission input member on the shaft, which may be limited by corresponding stops, ensures optimal, manufacturing tolerances balancing alignment of the stator and rotor of the electric motor and thus a particularly efficient operation of the electric motor.

Of particular advantage is an embodiment which is characterized in that the housing wall surrounding the wet space is diameter-reduced in the area of the driven member and the dry space is arranged around this diameter-reduced area.

According to this advantageous embodiment, the space provided for the control electronics dry space is arranged in a radial space around the shaft, so that a very compact drive unit is made possible.

Finally, it is provided that the drive unit is arranged part of the front wheel, the rear wheel or in the bottom bracket of the bicycle.

• 1 Schnittdarstellung einer erfindungsgemäßen Antriebseinheit.

Further advantages of the invention and a better understanding of the same are the following description of an embodiment:

• 1 Sectional view of a drive unit according to the invention.

A drive unit according to the invention is in the 1 total with the reference number 10 Mistake.

The drive unit 10 includes first a total with the reference number 11 designated housing, which along radial parting planes R is separated into a total of three housing parts. The housing 11 has a central through hole 12 through which a wave 13 is guided, which in the present example is the pedal crankshaft of a bicycle, not shown.

This along radial dividing planes R split housing 11 initially has a first housing part 14 which is a room 15 for an electric motor 16 forms whose stator 17 on an outer peripheral wall 18 of the first housing part 14 is attached. The rotor 19 the electric motor is near an inner peripheral wall 20 of the first housing part 14 arranged, which, starting from a radial wall 21 is retracted into the housing interior and sleeve-like the shaft 13 surrounds.

The wave 13 is by means of a first camp 22 supported on the inner peripheral wall 20. The through the inner peripheral wall 20 formed sleeve section 23 holds against the wave 13 a distance, so that between sleeve section 23 the inner peripheral wall 20 and the wave 13 a space 24 arises. This space 24 is used according to the proposal of the invention for the arrangement of at least one sensor unit, not shown here. By means of such sensor units are relevant control values for the control of the electric motor 16 detected. This is, for example, that at the shaft 13 applied torque, the speed of the shaft 13 and similar. The installation space 24 Can be separated from the rest of the housing interior by means of a radial wall, not shown here, if necessary.

A second housing part 25 forms a gear compartment 26 out, the recording of a transmission 27 and an output member 28 serves. The gear compartment 26 goes into the engine compartment 15 over, leaving the engine compartment 15 and the gear room 26 together form a housing interior. This housing interior is provided with a suitable lubricant for in particular the transmission 27 filled and is therefore to be called a "wet room".

The gear 27 has an input shaft 28 , which is designed as a hollow shaft. This hollow shaft is about second bearings 29 on the wave 13 held, which may be, for example, needle bearings. On the outside wall 30 of the second housing part 25 a ring gear 31 is fixed, which is the rotationally fixed part of the transmission 27 forms. Between the input shaft 28 and the ring gear 31 is at least one translation song 32 arranged, with the help of which the speed and the torque of the electric motor 16 is changed in a suitable manner. In the transmission 27 it is preferably a single-stage gearbox, multi-stage gearboxes are not excluded. The invention proposes here cycloidal or planetary gear as particularly preferred transmission variants.

Special attention is the input shaft 28 of the transmission 27 to give. This is with the rotor 19 connected so that the rotor 19 by means of the input shaft 28 and their second bearings rotatory on the shaft 13 is held. A separate storage of the rotor 19 opposite the wave 13 or the sleeve section 23 the inner peripheral wall 20 is therefore superfluous. This ensures the possibility of installation space 24 between engine 16 and wave 13 to accomplish. The transmission input shaft is axially floating at least within limits and thus axially displaceable. This can cause the rotor 19 automatically to the stator 17 align. Manufacturing and assembly tolerances can be compensated in this way.

That in the gearbox 26 arranged output member 33 is as the wave 13 surrounding output sleeve 34 educated. She is about third camp 35 on the wave 13 and over fifth camps 43 on the housing 11 supported. The wave 13 is about a first freewheel 36 Direction of rotation defined with the shaft 13 rotationally coupled. A rotation of the wave 13 is thus on the freewheel 36 transmitted to the output sleeve 34 in a defined direction of rotation. A shaft stall or reverse rotation of the shaft 13 has due to the freewheel 36 on the direction of rotation of the output sleeve 34 no influence.

The reduction element 32 is in the present embodiment, in which the transmission 27 is designed as a cycloidal gear, by means of a transmission output shaft 37 with the output sleeve 34 rotationally coupled. It is also the transmission output shaft 37 designed as a hollow shaft. The output sleeve 34 is inside the transmission output shaft 37 held. The transmission output shaft 37 relies on fourth camp 38 at the output sleeve 34 off and is about a second freewheel 39 with the output sleeve 34 direction-defined rotation-coupled. In this way, the output sleeve is used 34 as a summing element, on which the driving forces of the engine 16 and the wave 13 be merged.

On the output sleeve 34 is then outside the housing 11 a chainring 40 arranged, by means of which in the usual way the summed driving force is delivered to the rear wheel of a bicycle.

Without further ado, the drive unit 10 be designed as a rear wheel or front wheel drive for a bicycle according to the above description. In this case, a wheel axle would be arranged inside the shaft 13. The driving forces of the shaft 13 and the engine 16 would turn over the output sleeve 34 merged. Instead of the chainring 40 would be a wheel hub to be set.

Again 1 can be seen, the first housing part has a radius D whereas the second housing part 25 about its axial extent of a radius D on a radius d rejuvenated. This creates space to a third housing part 41 to the second housing part 25 to set, which in turn the radius D and thus concentrically around the narrowed in the radius portion of the second housing part 25 is arranged around. Between the third housing part 41 and the second housing part 25 becomes a receiving space in the rejuvenated area 42 created, facing the wet housing interior, consisting of engine compartment 15 and gear compartment 26 is delimited. It is thus a "dry space" which is not filled with gear lubricant and so to the arrangement of the control electronics for the engine 16 serves. The third housing part 41 can be designed axially removable in whole. Alternatively, the third housing part 41 have an axialweisende, closable with a lid opening. This makes it easy to use the control electronics and it also creates a maintenance access.

Overall, the invention proposes an optimized drive unit 10 ago, which by an optimized arrangement of the engine and transmission components as well as an adapted shape of the housing 11 additional rooms 24 and 41 for the reception of Sensors and control electronics creates. The axially floating bearing of the rotor 19 also allows a manufacturing and assembly tolerances correcting, self-optimizing alignment of the rotor 19 to the stator 17 and thus an optimized engine performance.

Overall, such a drive unit 10 be created, which contains all the relevant components in a compact design and can be pre-assembled optimized in a bicycle manufacturing handle.

LIST OF REFERENCE NUMBERS

10

drive unit

11

casing

12

Through Hole

13

wave

14

first housing part

15

engine compartment

16

electric motor

17

stator

18

Outer peripheral wall

19

rotor

20

Inner circumferential wall

21

radial wall

22

first camp

23

sleeve section

24

space

25

second housing part

26

gear compartment

27

transmission

28

Transmission input shaft

29

second camp

30

outer wall

31

ring gear

32

Reduction element

33

driven member

34

output socket

35

third camp

36

first freewheel

37

Transmission output shaft

38

fourth camp

39

second freewheel

40

chainring

41

third housing part

42

accommodation space

43

fifth camp

R

radial parting plane

D

radius

d

radius

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102014117137 B4 [0003]
• DE 102009014246 A1 [0004]
• DE 102013108549 B4 [0005]

Claims (17)

Drive unit (10) for a bicycle - comprising a housing (11) forming a wet space (26/15) filled with a lubricant, - having a shaft (13) rotatably supported by the housing (11), by means of which a first Torque is introduced, - with an in the housing coaxially around the shaft (13) arranged around the electric motor (16), by means of which a second torque is introduced, - with a in the output member (33/34), which of the addition of the first and the second Torque is used - with an at least single-stage, in the housing (11) arranged gear (27), which in the power flow between the electric motor (16) and output member (33/34) is arranged, - with a between motor (16) and shaft (13 ), which measured values of the shaft (13), such as torque and / or speed detected, characterized in that - the housing (11) along radial parting planes (R) is divided into three housing parts, - in the housing (11) additional, drier Space (42) is provided, in which electronic components, in particular the control electronics for the electric motor (16) are arranged. Drive unit to Claim 1 , characterized in that the dry space (42) concentrically around the shaft (13) around and in particular has an axially facing, closable with a lid opening. Drive unit to Claim 1 or 2 , characterized in that the housing (11) concentrically arranged around the shaft (13) around, sleeve-like retraction (20/23) is formed, which defines a between the shaft and the electric motor (16) arranged annular space (24). Drive unit to Claim 3 , characterized in that the annular space (24) serves to receive the sensor unit. Drive unit to Claim 4 , characterized in that the annular space (24) opposite to the axially adjacent wet space (15/26) is separated. Drive unit to Claim 3 , characterized in that the rotor (19) of the electric motor (16) is arranged externally around the sleeve-like housing pull-in (23). Drive unit according to one of the preceding claims, characterized in that a transmission input member (28) concentrically and rotatably mounted on the shaft (13) is arranged and that the rotor (19) of the electric motor (16) on the transmission input member (28) and by means of which Shaft (13) is mounted. Drive unit to Claim 7 , characterized in that the transmission input member (28) is mounted axially displaceably on the shaft (13). Drive unit according to one of the preceding claims, characterized in that the housing (11) is constructed in several parts by at least one radial parting plane (R). Drive unit according to one of the preceding claims, characterized in that the drive unit (10) is arranged part of the front wheel, the rear wheel or in the bottom bracket of the bicycle. Drive unit to Claim 1 , characterized in that a first housing part (14) forms a space (15) for an electric motor. Drive unit to Claim 12 , characterized in that the stator (17) of the motor (16) is fixed to an outer peripheral wall of the first housing part (14). Drive unit to Claim 1 , characterized in that a second housing part (25) forms a gear chamber (26). Drive unit to Claim 14 , characterized in that the gear chamber (26) receives the gear (27) and an output member (28). Drive unit to Claim 14 , characterized in that the gear chamber (26) merges into the engine compartment (15) and forms together with this the filled with lubricant wet space. Drive unit to Claim 14 , characterized in that the second housing part (25) tapers over its axial extent from a radius D to a radius d and that the third housing part (41) has a diameter D and around the radiused portion of the second housing part (25) around is arranged. Drive unit to Claim 17 , characterized in that between the third housing part (41) and the second housing part (25) a receiving space (42) is provided.

Images