WO2020020976A1

WO2020020976A1 - Bicycle having a dual electrical auxiliary drive

Info

Publication number: WO2020020976A1
Application number: PCT/EP2019/069977
Authority: WO
Inventors: Stephan Rebhan; Oliver Krieg
Original assignee: Vitesco Technologies Germany Gmbh
Priority date: 2018-07-27
Filing date: 2019-07-24
Publication date: 2020-01-30
Also published as: DE102018212584B3

Abstract

The invention relates to a bicycle having an electrical auxiliary drive having a bicycle frame (1) comprising a saddle tube (2) and a bottom tube (3), which run together in a crankcase (6), wherein a rotatably mounted crankshaft (11) is arranged in the crankcase (6), and in addition a planetary gear train (7) is arranged in the crankcase (6), wherein the planetary gear train (7) is coupled mechanically on the drive side to the crankshaft (11) and on the output side to an output component (12) of the bicycle, wherein a first electric motor (4) is arranged in the saddle tube (2) and a second electric motor (5) is arranged in the bottom tube or vice versa, or the first electric motor (4) and the second electric motor (5) are arranged in the saddle tube (2) or in the bottom tube (3), and the first electric motor (4) and the second electric motor (5) are mechanically coupled to the planetary gear train (7) by means of corresponding motor shafts (4.1, 5.1).

Description

description

BICYCLE WITH DOUBLE ELECTRIC AUXILIARY DRIVE

The invention relates to a bicycle with an electric auxiliary drive with a bicycle frame comprising a seat tube and a down tube, which converge in a crankcase, wherein a rotatably mounted crankshaft is arranged in the crankcase, and furthermore at least one epicyclic gear is arranged in the crankcase, the epicyclic gear on the drive side is mechanically coupled to the crankshaft and on the output side to an output component of the bicycle.

Bicycles with an electric auxiliary drive are divided into two categories, e-bikes and pedelecs. Pedelec is short for Pedal Electric Cycle and e-bikes are electric bikes. The difference between the two lies in the power support.

On an e-bike, the signal for this comes from a turning handle on the steering wheel, such as a moped, and is often more powerful than the pedelec. The motor switches on when the rotary handle is actuated. The engine power of the e-bike can be switched on regardless of the driver pedaling.

With the pedelec, motor support is only permitted in addition to pedaling by the driver. The level of motor support can be regulated manually or automatically. This makes it easier to tackle uphill stretches. In addition, some models have a traction help that drives at up to six km / h even without pedaling. When operating a pedelec in the EU, the engine switches off automatically at a speed of 25 km / h, when operating in the USA this only happens at 32 km / h. With the so-called S-Pedelec, engine support ends at 45 km / h when operating in the EU and is therefore subject to registration and insurance. A driving license is also required for a certain group of people.

There are electric bicycles in which the electric drive is arranged in the area of the crankshaft bearing as a mid-engine concept. A rear wheel is then driven via a chain or a similarly acting means, for example a drive belt.

Such an electric bike with a supportive

Electric motor in the area of the crankshaft bearing is known from EP 1 298 051 A2.

WO 2016/034574 A1 shows an electric bicycle, the drive comprising a first and a second electric motor and a planetary gear system with a planet carrier, a ring gear and a sun gear. The first motor is used to provide a certain speed ratio between the pedal and the output sprocket. The second motor is used to ensure that the level of support selected by the driver is maintained. The disadvantage here is that the crankcase with the transmission and the two motors takes up a relatively large amount of space.

DE 10 2006 032 016 B4 shows a bicycle with a

Bicycle frame with a seat tube and a down tube. A seat post that carries a saddle can be inserted into the seat tube. A crankshaft is arranged in the crankcase. Pedal cranks are attached to the two ends of the crankshaft with pedals, with which an output chainring can be rotated in order to drive a bicycle chain running over it and thus the rear wheel of the bicycle.

Inside the seat tube is an engine with a gearbox arranged, which reduces the speed of the engine accordingly and can rotate a bevel gear arranged in the seat tube and crankcase via a freewheel, which acts on the crankshaft. The disadvantage here is that the power of one engine and the transmission capacity of the transmission are low due to the location in the frame, and the transmission ratio of the drive is structurally fixed and not variable

It is therefore the object of the present invention to provide a bicycle with an electric auxiliary drive which has a large motor support with a sufficiently large and variable transmission range with simultaneous little effort for the space required.

This object is achieved by a bicycle with the features mentioned in claim 1. In the bicycle according to the invention with an electric auxiliary drive consisting of two electric motors, a first electric motor is arranged in the seat tube and a second electric motor in the down tube of the bicycle frame. Conversely, the first electric motor can be arranged in the down tube and the second electric motor in the seat tube of the bicycle frame. Alternatively, the first electric motor and the second electric motor can be accommodated together in the seat tube or in the down tube. The first electric motor and the second electric motor are mechanically coupled to an epicyclic gear or a coupling gear in the crankcase of the bicycle by means of corresponding motor shafts.

In particular, this is an epicyclic gearbox with three inputs, comprising the two electric motors and the muscular strength of the driver via the crankshaft and with one output, the output component, for example an output chainring for driving the rear wheel of the bicycle. Such a planetary gear has in particular properties such as large load capacities and large transmission ratios in a small installation space and the superimposition of torques and speeds, the speed ratios being variable and adjustable or controllable at least between two of the inputs and outputs.

In particular, the bicycle has a control unit which can regulate the first electric motor by means of a torque signal and the second electric motor by means of a speed signal, or vice versa, wherein the electric motors can be designed, for example, as brushless DC motors.

A freewheel is advantageously arranged between the crankshaft and the output component. This primarily prevents the output component, such as an output chainring, from rotating more slowly than the crankshaft.

In particular, the epicyclic gear can be designed as a planetary gear and the output component or the output chainring can be mechanically coupled on the output side to the planet gear carrier of the planetary gear. The crankshaft is then mechanically connected in particular to the first or the second electric motor and to the ring gear or the sun gear on the drive side.

Alternatively, the output component can be mechanically coupled to the ring gear of the planetary gear on the output side. The crankshaft is then connected on the drive side in particular to the first or the second electric motor and to the planet gear carrier or the sun gear. Furthermore, the output component can be mechanically coupled to the sun gear of the planetary gear on the output side. The crankshaft is then connected on the drive side in particular to the first or the second electric motor and to the tarpaulin tarpaulin or the ring gear.

In particular, the mechanical coupling of a motor shaft of the respective electric motor to the epicyclic gear by means of known connection techniques can be non-positive, positive or frictional.

This mechanical coupling can preferably be produced as a pairing of two gearwheels such as, for example, two crown gears or two bevel gears. This advantageously creates a drive with the power of two electric motors and a gearbox in a small installation space.

Because the one crown gear or bevel gear coupling with the crankshaft and the corresponding one motor shaft and the corresponding crown gear or bevel gear coupling with the other motor shaft are arranged with respect to one another, in particular opposite, that overall an axial force-compensated design of the drive is provided, the crankcase can advantageously be thinner and therefore lighter.

In the following description, the features and details of the invention are explained in more detail in connection with the accompanying drawings using exemplary embodiments. The drawings show:

Fig. 1 is a bicycle with an electric auxiliary drive with a

Electric motor in the seat tube and an electric motor in the down tube, Fig. 2 a bicycle with an electric auxiliary drive with both electric motors

in the seat tube,

3a shows a first embodiment of a drive in which the output chainring is coupled to the planet gear carrier, and each with an electric motor in a frame tube,

Fig. 3b shows a drive as in Fig. 3a, but with both

Electric motors in

Seat tube or in the down tube of the bicycle frame, Fig. 4 shows a second embodiment of a drive in which the

Output chainring is coupled to the planet carrier, and with two electric motors in a frame tube,

5a shows a first embodiment of a drive in which the

Output chainring is coupled to the ring gear, and with two electric motors in a frame tube,

Fig. 5b a drive as in Fig. 5a, but with one

switching coupling of an electric motor to the cure belwelle,

Fig. 6 shows a second embodiment of a drive, in which the

Fig. 7 shows a first embodiment of a drive in which the

Output chainring is coupled to the sun gear, and with both electric motors in a frame tube,

Fig. 8 shows a second embodiment of a drive, in which the

9 shows a drive with more than one planetary gear, and with two electric motors in a frame tube, and FIG. 10 shows a schematic representation of a drive with a

Epicyclic gearbox with three inputs and one output. 1 schematically shows a bicycle with a bicycle frame 1 comprising a seat tube 2 and a down tube 3, the seat tube 2 and the down tube 3 converging in a crankcase 6. A first electric motor 4 is in the seat tube 2, and a second electric motor 5 is housed in the down tube 3, or vice versa. An epicyclic gear 7, which is designed here as a planetary gear, is arranged in the crankcase 6. The planetary gear 7 usually comprises a ring gear 8, a sun gear 9 and a planet gear carrier 10, these individual components of the planetary gear being not shown here. Furthermore, a rotatably mounted cure belwelle 11 is arranged in the crankcase 6. At the two ends of the crankshaft 11, crank arms 14 are fastened, each with a pedal 15, by means of which the output component 12, here an output chainring 12, can be rotated in order to drive a bicycle chain 13 running therewith and thus the rear wheel 16 of the bicycle. Instead of the bicycle chain 13, another means having the same effect, such as a drive belt, could also be used. A battery 17 is attached to the down tube 3. The battery 17 supplies the first electric motor 4 and the second electric motor 5 with current. The battery 17 could also be attached to the seat tube 2 or another suitable location on the bicycle. It would also be conceivable to accommodate the battery 17 in the bicycle frame 1. Each of the two electric motors 4, 5 could also be supplied with power by its own battery. The connecting cables between the battery 17 and the electric motor 4, 5 are not shown here. The connecting cables could not be visibly laid in the bicycle frame 1 for aesthetic reasons.

The bicycle also has a control unit 18, which regulates the first electric motor 4 by means of a torque signal and the second electric motor 5 by means of a speed signal can, or vice versa. The torque of an electric motor could, for example, be calculated using the current introduced into the electric motor. The speeds could in particular be determined using Hall sensors, not shown here. The corresponding torque and speed signals can be passed on to the control unit, either by cable or wirelessly.

Fig. 2 shows schematically a bicycle as shown in Fig. 1, with the difference that the first electric motor 4 is arranged together with the second electric motor 5 in the seat tube 2. Alternatively, the two electric motors 4, 5 could also be accommodated together in the down tube 3.

Fig. 3a to Fig. 9 show schematically various On events of a drive with a crankcase, not shown here, with a crankshaft 11 and at least one planetary gear 7 with a ring gear 8, a sun gear 9 and a planet gear carrier 10, the planetary gear 7 on the drive side or input side is mechanically coupled to the crankshaft 11 and on the output side or output side to an output chainring 12 of the bicycle. A first electric motor 4 is arranged in the seat tube and a second electric motor 5 is arranged in the down tube, or vice versa, or the first electric motor 4 and the second electric motor 5 are arranged together in the seat tube or in the down tube. The first electric motor 4 and the second electric motor 5 are mechanically coupled to the planetary gears 7, 8, 9 and 10 by means of corresponding motor tor shafts 4.1, 5.1 of the first electric motor 4 and the second electric motor 5 by means of corresponding pairings of crowns 20. In particular, it could also be a pair of bevel gears, but this is not shown here. 3a to 9 are for clarity for the sake of not showing the electric motors 4, 5 themselves and the bicycle frame.

The crankshaft 11 is rotatably mounted in the crankcase, not shown, by means of a bearing 23. At the two ends of the crankshaft 11 crank arms 14 are fastened, by means of which the output chainring 12 can be set in rotation. A freewheel 19 is arranged between the crankshaft 11 and the output chainring 12 in such a way that the output chainring 12 is prevented from rotating more slowly than the crankshaft 11.

Fig. 3a shows a first embodiment of a drive in which the output chainring 12 is coupled to the planet carrier 10 ge, and each with an electric motor in a frame tube, either the down tube or the seat tube. On the drive side, the first or the second electric motor is mechanically connected to the sun gear 9 via the corresponding motor shafts 4.1, 5.1 by means of a crown gear pair comprising two crown gears 20, which is in particular fixedly mounted on the crankshaft 11. The crankshaft 11 could also be formed in one piece with the sun gear 9. The further electric motor acts via the corresponding motor shaft 4.1, 5.1 on the ring gear 8 of the planetary gear 7.

Fig. 3b shows a drive as shown in Fig. 3a, but with both electric motors in the seat tube or in the down tube of the bicycle frame. One of the motor shafts 4.1, 5.1 is in particular designed as a hollow shaft in which the other motor shaft 4.1, 5.1 is rotatably guided.

Fig. 4 shows a second embodiment of a drive in which the output chainring 12 is coupled to the planet carrier 10 ge. Both electric motors are preferably in here ordered a frame tube of the bicycle frame, not shown.

On the drive side, the first or the second electric motor is mechanically connected to the ring gear 8 via the corresponding motor shafts 4.1, 5.1, which in turn is operatively connected to the crankshaft 11. The further electric motor is in engagement with the sun gear 9 of the planetary gear 7 via the corresponding motor shaft 4.1, 5.1.

5a shows a first embodiment of a drive in which the output chainring 12 is mechanically coupled to the ring gear 8. In particular, the two electric motors are housed in a frame tube of the bicycle frame.

On the drive side, the first or the second electric motor is mechanically connected to the sun gear 9 via the corresponding motor shafts 4.1, 5.1 by means of a pair of crown gears from two crown gears 20, which is in particular firmly mounted on the cure 11. The crankshaft 11 could also be formed in one piece with the sun gear 9. The further electric motor acts on the planet carrier 10 of the planetary gear 7 via the corresponding motor shaft 4.1, 5.1.

5b shows a drive as in FIG. 5a, but with a different coupling of an electric motor to the crankshaft 11, the corresponding crown gear 20 being arranged on the side of the crankshaft facing away from the sun gear 9.

Because this crown gear and the corresponding crown gear coupling with the other motor shaft are arranged on the side facing the sun gear 9, that is to say opposite, an overall axial force-compensated design of the drive is achieved in this area. As a result, the crankcase can advantageously be made thinner, which in particular leads to a weight saving. Fig. 6 shows a second embodiment of a drive, in which the output chainring 12 is coupled to the ring gear 8, with both electric motors in a frame tube.

On the input side, the first or the second electric motor is mechanically connected to the planet gear carrier 10 via the corresponding motor shafts 4.1, 5.1, which in turn is operatively connected to the crankshaft 11. The further electric motor is in engagement with the sun gear 9 of the planetary gear 7 via the corresponding motor shaft 4.1, 5.1.

7 shows a first embodiment of a drive in which the output chainring 12 is coupled to the sun gear 9. Both electric motors are housed in a frame tube, for example.

On the drive side, the first or the second electric motor is mechanically connected to the planet wheel carrier 10 via the corresponding motor shafts 4.1, 5.1, which is preferably fixedly mounted on the crankshaft 11. The further electric motor acts on the ring gear 8 of the planetary gear 7 via the corresponding motor shaft 4.1, 5.1.

FIG. 8 shows a second embodiment of a drive, in which the output chainring 12 is coupled to the sun gear 9, in particular with both electric motors in a frame tube. On the input side, the first or the second electric motor is mechanically connected to the ring gear 8 via the corresponding motor shafts 4.1, 5.1, which in turn is operatively connected to the crankshaft 11. The further electric motor acts on the planet carrier 10 of the planetary gear 7 via the corresponding motor shaft 4.1, 5.1.

Fig. 9 shows a drive with more than one planetary gear, namely with an upstream planetary gear 7.1, the planetary gear 7 and the downstream planetary gear 7.2. The upstream planetary gear 7.1 includes a pre-ring gear 8.1, a pre-sun gear 9.1 and one

Pre-planet carrier 10.1. The downstream planetary gear 7.2 correspondingly comprises a post ring gear 8.2, a post sun gear 9.2 and a post planet carrier 10.2. 9, both electric motors are arranged in particular in a frame tube.

In the drive shown in FIG. 9, the pre-sun gear 9.1 is firmly connected to the crankshaft 11 on the drive side. The first or the second electric motor acts via the corresponding motor shafts 4.1, 5.1 on the ring gear 8 or on the tarpaulin 10 gear carrier 10. On the output side, the output chainring 12 is in operative connection with the post planet carrier 10.2.

In addition to the drive shown in FIG. 9, other drives with a plurality of compound planetary gears with further combinations of the inputs and outputs on the couplings to such a planetary gear assembly would also be conceivable. In particular, it would also be conceivable to couple additional gear stages on the drive side or on the output side in the crankcase or also outside the crankcase for the variable adaptation of the speed ratios.

Fig. 10 shows schematically the drive with a planetary gear 7 with three inputs, comprising the two electric motors 4, 5 and the crankshaft 11, via which the driver's muscle power is transmitted, and with an output 12, the output component, for example an output chainring Drive the rear wheel of the bike. Such an epicyclic gearbox has in particular properties such as large transmission powers and large transmission ratios in a small installation space and the superimposition of torques and speeds, with the speed ratios being variable and adjustable or controllable at least between two of the inputs and outputs are. The epicyclic gear can be designed in particular as a coupling gear, in particular as a planetary gear.

Reference character list

1 bicycle frame

2 seat tube

3 down tube

4 first electric motor

4.1 Motor shaft, first electric motor

5 Second electric motor

5.1 Motor shaft, second electric motor

6 crankcase

7 planetary gear, epicyclic gear, coupling gear

7.1 Upstream planetary gear

7.2 Downstream planetary gear

8 ring gear

8.1 Pre ring gear

8.2 Post ring gear

9 sun gear

9.1 Pre sun gear

9.2 Post sun gear

10 planet carriers

10.1 Pre planet carrier

10.2 Post planet carrier

11 crankshaft

12 output component, output chainring

13 bicycle chain

14 crank arm

15 pedal

16 rear wheel

17 battery

18 control unit

19 freewheel

20 crown gear

21 bevel gear

22 planet

23 bearings

Claims

claims

1. Bicycle with electric auxiliary drive with a bicycle frame (1) comprising a seat tube (2) and a down tube (3), which converge in a crankcase (6), wherein a rotatably mounted crankshaft (11) is arranged in the crankcase (6) , and further an epicyclic gear (7) is arranged in the crankcase (6), the epicyclic gear (7) being mechanically coupled on the drive side to the crankshaft (11) and from the drive side to an output component (12) of the bicycle, characterized in that

a first electric motor (4) is arranged in the seat tube (2) and a second electric motor (5) in the down tube (3), or vice versa, or

the first electric motor (4) and the second electric motor (5) are arranged in the seat tube (2) or in the down tube (3), and the first electric motor (4) and the second electric motor (5) with the epicyclic gear (7) by means of corresponding motor shafts (4.1, 5.1) are mechanically coupled.

2. Bicycle according to claim 1, characterized in that the

Bicycle has a control unit (18) which controls the first electric motor (4) by means of a torque signal and the second electric motor (5) by means of a speed signal, or vice versa.

3. Bicycle according to claim 1 or 2, characterized in that a freewheel (19) is arranged between the crankshaft (11) and the output component (12), which prevents the output component (12) from rotating more slowly than the crankshaft (11)

4. Bicycle according to one of the preceding claims, characterized in that the epicyclic gear (7) is a tarpaulin gear and the output component (12) is mechanically coupled to the planet gear carrier (10) on the output side, and the crankshaft (11) with the first electric motor ( 4) or the second electric motor (5) and mechanically coupled to the ring gear (8) or the sun gear (9) on the drive side.

5. Bicycle according to one of claims 1 to 3, characterized in that the epicyclic gear (7) is a planetary gear and the output component (12) with the ring gear (8) is mechanically coupled on the output side, and the

Crankshaft (11) with the first electric motor (4) or the second electric motor (5) and with the planet gear carrier (10) or the sun gear (9) is mechanically coupled on the drive side.

6. Bicycle according to one of claims 1 to 3, characterized in that the epicyclic gear (7) is a planetary gear and the output component (12) with the

Sun gear (9) is mechanically coupled on the output side, and the crankshaft (11) with the first electric motor (4) or the second electric motor (5) and with the planet carrier (10) or the ring gear (8) is mechanically coupled on the drive side.

7. Bicycle according to one of the preceding claims, characterized in that the first electric motor (4) and the second electric motor (5) are each a brushless DC motor.

8. Bicycle according to one of the preceding claims, characterized in that the mechanical coupling of a Motor shaft (4.1, 5.1) with the epicyclic gear (7) is non-positive, positive or frictional.

9. Bicycle according to claim 8, characterized in that the mechanical coupling of a motor shaft (4.1, 5.1) with the

Epicyclic gear (7) as a pair of two crown gears (20) or two bevel gears (21).

10. Bicycle according to claim 9, characterized in that one with the crankshaft (11) and the corresponding one motor shaft (4.1, 5.1) coupling crown gear (20) or bevel gear (21) and the corresponding with the other motor shaft (4.1, 5.1 ) coupling crown gear (20) or bevel gear (21) are arranged in relation to one another in such a way that an axial force-compensated design of the drive is provided.

11. Bicycle according to one of the preceding claims, characterized in that the output component (12) is designed as an output chainring.