EP2250073A2

EP2250073A2 - Chain gear, vehicle comprising a chain gear and method for gearing an engine torque in a vehicle

Info

Publication number: EP2250073A2
Application number: EP09709426A
Authority: EP
Inventors: Rudolf Höbel
Original assignee: Clean Mobile AG
Current assignee: TQ Systems GmbH
Priority date: 2008-02-04
Filing date: 2009-02-04
Publication date: 2010-11-17
Also published as: CN102015429B; WO2009098647A2; CN102015429A; WO2009098647A3; US20110120794A1; AU2009211107A1; EP2250073A4; JP2011510870A; CN104724245A

Abstract

A chain gear (1) for gearing an engine torque comprises three gearing stages, wherein the first gearing stage is formed by a first gear rim (6) and a fourth gear rim (9), the second gearing stage is formed by a second gear rim (7) and a fifth (10) gear rim, and the third gearing stage is formed by a third gear rim (8) and a sixth gear rim (11). The first gear rim (6), the second gear rim (7) and the third gear rim (8) are disposed on a first shaft (3), and the fourth gear rim (9), the fifth gear rim (10) and the sixth gear rim (11) are disposed on a second shaft (4). A transmission chain (27, 28, 29) is provided in each gearing stage for transmitting the torque.

Description

description

CHAIN TRANSMISSION, VEHICLE WITH CHAIN TRANSMISSION AND METHOD FOR TRANSLATING A MOTOR TORQUE IN A VEHICLE

The invention relates to a chain transmission and a vehicle with a chain transmission, which has both a pedal drive and a drive by an electric motor. It further relates to a method for translating a motor torque in a vehicle.

[2] Bikes with electric motors such as bicycles with electric

Drive generally have a transmission so that the electric motor can be operated at a low speed, but at the same time pedaling at a convenient frequency for the driver is possible.

From DE 20 2007 002 368 Ul a bicycle with a designed as a hollow shaft motor electric motor is known, which has a gear transmission, for example, a planetary gear.

From DE 40 27 365 Al a bicycle is attached to a bicycle frame

Electric motor with built-in reduction gear known, wherein the torque is transmitted from the electric motor by means of a chain on the bottom bracket. A similar bicycle is also known from DE 299 04 342 Ul.

The object of the invention is to provide a transmission with which a translation of

Torque of an electric motor with high reliability, good maintainability and high efficiency can be realized.

[6] In addition, it is a further object of the present invention to provide a vehicle with such a transmission, which can be operated in a particularly energy-saving manner and at the same time offers a high level of comfort for the driver.

[7] According to the invention, this object is achieved with the subject matter of the independent

Claims solved. Advantageous developments of the invention are the subject of the dependent claims.

[8] An inventive transmission is designed as a chain transmission. It has three

Translation stages, wherein the first gear stage by a first sprocket and a fourth sprocket, the second gear stage by a second sprocket and a fifth sprocket and the third gear stage is formed by a third sprocket and a sixth sprocket. The first sprocket, the second sprocket and the third sprocket are arranged on a first shaft and the fourth sprocket, the fifth sprocket and the sixth sprocket are arranged on a second shaft. To transmit the torque, a transmission chain is provided in each gear ratio. [9] According to a concept underlying the invention, a chain transmission has a comparatively high degree of efficiency coupled with good maintainability. However, chain transmissions may require more space than, for example, gear transmissions. Thus, a space-saving arrangement of the individual components of the chain transmission is desirable. A three-stage design of the chain transmission is favorable, since in this case the required sprockets can be arranged on two shafts, one of which is designed as an output shaft of the electric motor or connected thereto. The other shaft is designed as a bottom bracket of the vehicle. Thus, the three chains can be very space-saving arranged substantially parallel to each other.

At the same time can be with the three-stage chain transmission a sufficiently large

Reduction achieve in order to operate the electric motor in a low speed range of for example 2500 revolutions per minute and still ensure a high level of ride comfort, since a reduction of, for example, 1:45 can be achieved.

[11] In one embodiment, therefore, the gear ratio of the chain transmission is less than 1, so that a reduction of the engine speed takes place.

[12] In one embodiment, the first sprocket has a number ni of

Teeth, the second sprocket has a number n ₂ , the third sprocket has a number n ₃ , the fourth sprocket has a number n ₄ , the fifth sprocket has a number n ₅ and the sixth sprocket has a number n ₆ , where ^ <n ₄ , n ₃ <n ₆ and n ₅ <n ₂ applies. Thus, in each translation stage, a reduction takes place.

[13] In one embodiment, ^ = n ₃ = n ₅ and n ₂ = n ₄ = n ₆ . There are provided according to this embodiment, therefore three equal small sprockets and three equal large sprockets. This design is particularly simple and has the additional advantage that it has a high degree of symmetry, so that three similar chains can be used as transmission chains.

The transmission according to the invention can thus be composed of particularly few different components, if three identical chains and two sets of three identical sprockets, the three identical sprocket combinations are used. Alternatively, the translation can also be varied by replacing a sprocket or a sprocket pair.

In one embodiment, the second sprocket and the third sprocket are arranged on a common first hollow shaft whose axis of rotation coincides with the axis of rotation of the first shaft. The fourth sprocket and the fifth sprocket are arranged on a common second hollow shaft whose axis of rotation coincides with the axis of rotation of the second shaft. By using the hollow shafts a particularly compact construction of the transmission is achieved.

[16] In an alternative embodiment, split shafts are used instead of the hollow shafts or instead of one of the hollow shafts. For example, the first shaft may be formed divided and have a first portion and a second portion which are separate from each other but rotatable about the same axis. The first portion of the first shaft is connected to the electric motor. The first sprocket is on the first area and the second sprocket and the third sprocket are arranged on the second area of the first shaft.

[17] In one embodiment, the sixth sprocket has a first freewheel. It is thus also possible to use the vehicle with the engine switched off, because by means of the freewheel, the rotational movement of the sixth ring gear and thus the motor of the rotational movement of the second shaft and thus the pedals can be decoupled.

The chain transmission according to the invention can be achieved in a vehicle, a large reduction of the engine torque and at the same time saves space. It is thus possible to arrange the transmission in the area of the bottom bracket, which is also favorable with regard to a low center of gravity of the vehicle.

The chain transmission according to the invention can be made with a diameter which is smaller than or at most as large as the diameter of a conventional front sprocket. The chain transmission according to the invention can therefore be integrated particularly well in the vehicle frame and offers in the mounted state a large ground clearance and also a pleasing appearance. The chain transmission can thus be formed as an integral part of the vehicle frame. It is also advantageous in the use of a chain gear that it works very quiet and at the same time is easy to manufacture and offers high efficiency.

[20] In one embodiment, the gear ratio of the chain transmission is at least 1: 100 and at most 1:25, in one embodiment even at least 1:50 and at most 1:40. A gear ratio in this range allows a particularly good adaptation of the engine speed, which is conveniently on the order of at least 1000 revolutions per minute, to the cadence of an average driver.

[21] According to one aspect of the invention, a vehicle has the chain transmission according to the invention, wherein the vehicle has both a pedal drive and an electric motor drive. The output shaft of the electric motor and the output shaft of the pedal drive are coupled together by the chain transmission. In this case, in one embodiment, the first shaft is designed as the output shaft of the electric motor and the second shaft as the bottom bracket of the vehicle.

[22] For example, the vehicle may be used as a two-wheeler, tricycle or quadricycle be formed. If it is designed as a tricycle, both arrangements are conceivable in which two wheels are arranged side by side behind as well as those in which two wheels are arranged side by side in front. However, embodiments with a single front wheel have a more favorable behavior when cornering.

[23] Both the front wheel (s) and the rear wheel (s) can be driven.

[24] In one embodiment, a seventh sprocket is disposed on the second shaft connected by a chain to a rear sprocket of a rear wheel of the vehicle.

[25] Alternatively, the seventh ring gear is connected to the ring gear of a differential gear. This is particularly advantageous when the vehicle is designed as a four-wheel or tricycle, in which the two wheels arranged next to each other are driven.

The seventh ring gear advantageously has a second freewheel, so that a

Treten the driver or an operation of the electric motor during the movement of the vehicle is not necessary.

The chain transmission is particularly compact and can thus be easily arranged in a housing which is connected to a frame of the vehicle. The housing has at least a lateral protection, so that injury to the driver is excluded by the transmission chains. But it can also be formed predominantly closed, so that the penetration of dirt and moisture is largely prevented.

[28] According to one aspect of the invention, a method of translating engine torque in a vehicle having an electric motor drive and a pedal drive comprises the steps of: first translating the torque from a first ring gear to a fourth ring gear via a first gear train; second translation of the torque from a second sprocket by means of a second gear chain to a fifth sprocket; thirdly translating the torque from a third sprocket to a sixth sprocket by means of a third gear chain, the sixth sprocket being connected to a bottom bracket of the vehicle; Transferring the torque from the bottom bracket shaft by means of a chain to a rear sprocket associated with a rear wheel of the vehicle.

[29] In addition to the translated engine torque, a pedal torque can be applied to the bottom bracket shaft during operation of the vehicle.

[30] Embodiments of the invention will be described below with reference to the attached

Figures explained in more detail.

[31] Figure 1 shows schematically a perspective view of a chain transmission according to an embodiment of the invention;

[32] Figure 2 shows schematically a section of a vehicle with a chain transmission according to an embodiment of the invention and

FIG. 3 shows schematically a cross section through a chain transmission according to a

Embodiment of the invention.

[34] Identical parts are provided with the same reference numerals in all figures.

[35] Figure 1 shows schematically a perspective view of a chain transmission 1 according to an embodiment of the invention. The chain transmission 1 has a first sprocket 6, a second sprocket 7, a third sprocket 8, a fourth sprocket 9, a fifth sprocket 10 and a sixth sprocket 11, wherein the first sprocket 6, the second sprocket 7 and the third sprocket eighth on a first shaft 3 and the fourth sprocket 9, the fifth sprocket 10 and the sixth sprocket 11 on a second shaft 4 are arranged.

[36] The first shaft 3 is connected to the output shaft of an electric motor 5.

[37] The second shaft 4 is formed as a bottom bracket of a vehicle and has a first end 13 and a second end 14, wherein the first end 13 and the second end 14 are suitable for receiving cranks, not shown in the figure 1 with pedals ,

[38] The first ring gear 6, the third ring gear 8 and the fifth ring gear 10 have relatively small diameters and correspondingly a small number of teeth. The second ring gear 7, the fourth ring gear 9 and the sixth ring gear 11, however, have relatively large diameters and correspondingly a larger number of teeth.

[39] Between the sixth ring gear 11 and the second shaft 4 is a first freewheel

15, which enables a decoupling of the sixth ring gear 11 from the second shaft 4.

[40] On the second shaft 4, a seventh ring gear 12 is further arranged, which has a second freewheel 16.

[41] A first gear chain not shown for clarity connects the first sprocket 6 with the fourth sprocket 9, a second gear chain also not shown connecting the second sprocket 7 with the fifth sprocket 10 and a third gear chain also not shown connecting the third sprocket. 8 with the sixth ring gear 11.

[42] The chain transmission 1 is housed in a housing 2 which houses the first sprocket

6, the second sprocket 7, the third sprocket 8, the fourth sprocket 9, the fifth sprocket 10 and the sixth sprocket 11 and the first gear chain, the second gear chain and the third gear chain receives. In this case, the housing 2 is at least as side protection for the chain transmission 1 and for the driver of the Vehicle trained.

[43] In an alternative embodiment, not shown, the electric motor 5 is arranged within the housing 2.

[44] The electric motor 5 may be made small and operated at a high speed. In this way it is possible to provide a particularly compact drive unit for a vehicle, which also has a high efficiency.

FIG. 2 schematically shows a detail of a vehicle with a chain transmission 1 according to an embodiment of the invention.

[46] In the embodiment shown, the vehicle is designed as a two-wheeler. The

Chain transmission 1 is integrated in the frame 17 of the vehicle and comprises the bottom bracket of the vehicle, wherein on the second shaft 4 cranks 18 are arranged with pedals 19. A chain 21 connects the seventh ring gear 12 with a rear sprocket 20 on the rear wheel of the bicycle.

In an embodiment, not shown here, in which the vehicle is designed as a four-wheel or tricycle with two driven wheels, the chain connects the seventh ring gear with the ring gear of a differential gear.

[48] The vehicle may also have on its rear wheel a sprocket set of a circuit, of which, however, only the rear sprocket 20 is shown symbolically in FIG.

FIG. 3 shows schematically a cross section through a chain transmission 1 according to a

Embodiment of the invention.

The first shaft 3 and the second shaft 4 are by means of ball bearings 22 in the

Housing 2 stored. The first ring gear 6 is fixedly connected to the first shaft 3 and welded thereto. The sixth ring gear 11 is connected to the second shaft 4, but its rotational movement can be decoupled from the rotational movement of the second shaft 4 via the first freewheel not shown in FIG.

[51] The second ring gear 7 is arranged together with the third ring gear 8 on a common first hollow shaft 23, whose axis of rotation coincides with the axis of rotation of the first shaft 3. The fourth ring gear 9 is arranged together with the fifth ring gear 10 on a second hollow shaft 24 whose axis of rotation coincides with the axis of rotation of the second shaft 4. The first hollow shaft 23 is mounted on the first shaft 3 by means of a first ball bearing 25, and the second hollow shaft 26 is mounted on the second shaft 4 by means of a second ball bearing 26.

[52] The first gear chain 27 connects the first ring gear 6 with the fourth

Sprocket 9, the second gear chain 28 connects the second sprocket 7 with the fifth sprocket 10 and the third gear chain 29 connects the third sprocket 8 with the sixth sprocket eleventh [53] The transmission chains 27, 28, 29 are designed, for example, as motor chains and can absorb high forces.

[54] The first shaft 3 is connected to the output shaft 31 of the electric motor 5 and received in a receptacle 30 of the output shaft 31. In this way, the electric motor 5 for maintenance or replacement purposes can be easily removed without the chain drive 1 must be removed.

In operation, the electric motor 5 drives the first shaft 3 at a relatively high speed of the order of at least 1000 revolutions per minute, for example at 2000 to 3500 revolutions per minute, for example at 2500 revolutions per minute.

[56] The first ring gear 6 fixedly arranged on the first shaft 3 transmits this

Torque by means of the first gear chain 27 on the fourth sprocket 9. In the illustrated embodiment, the first sprocket 6 17 teeth and the fourth sprocket 9 61 teeth. It thus follows for this first gear ratio, a reduction ratio of about

[57] 1: 3,59.

The fourth toothed rim 9 is arranged together with the fifth toothed rim 10 on the common second hollow shaft 24. The fifth sprocket 10, which has 17 teeth in the embodiment shown, transmits the torque further by means of the second gear chain 28 to the second sprocket 7, which has 61 teeth in the embodiment shown. Thus, there is also a reduction ratio of about 1: 3.59 for this second gear ratio.

The third ring gear 8 is arranged together with the second ring gear 7 on the common first hollow shaft 23. The third ring gear 8, which has 17 teeth in the illustrated embodiment, transmits the torque further by means of the third gear chain 29 to the sixth ring gear 11, which has 61 teeth in the illustrated embodiment. Thus, there is also a reduction ratio of about 1: 3.59 for this third gear ratio.

The chain transmission 1 according to the invention thus has three transmission stages or rather reduction stages, wherein these three gear ratios are similar in the embodiment shown, since the first ring gear 6, the third ring gear 8 and the fifth ring gear 10 and the second ring gear 7, the fourth sprocket 9 and the sixth sprocket 11 each having the same number of teeth. Thus, it is also possible to use three completely identical transmission chains 27, 28, 29.

[61] In another embodiment, the chains of the first two

Translation levels each have a thickness of 6 mm, while the chain of the third gear stage has a thickness of 8 mm. Overall, the chain drive according to the invention makes in the illustrated

Embodiment a reduction of about

[63] 1: 46.2 between the electric motor 5 and the second shaft 4 with the seventh

Sprocket 12. The rider's cadence can thus be a ratio of 1: 46.2 to the frequency of the electric motor. With typical comfortable pedaling frequencies of the driver, corresponding to 45 to 70 revolutions per minute, it is thus possible to operate the electric motor at high speed at 2000 to 3200 revolutions per minute in a range with high efficiency.

[64] Figure 4 shows another transmission in which in comparison to the transmission of FIG

3 additionally has a freewheel 38. In a first embodiment, the freewheel 38 is provided so that the motor 5 can drive the seventh ring gear 12 via the transmission, without the pedals turning with it.

[65] In a second embodiment, the freewheel is additionally blocked. This is particularly advantageous when braking energy is to be used for the recuperation of electrical energy. As a result, the impeller can drive the electric motor 5 in generator mode via the seventh ring gear, without the freewheel 38 preventing this.

[66] In a third embodiment, the freewheel 38 is switchable with respect to the direction. This allows a reverse gear, in which the electric motor changes its direction of rotation and thus drives the vehicle backwards. The freewheel causes here, too, that the pedals do not have to turn. The switching also allows the recuperation described above.

[67] list of reference numerals

[68] 1 chain transmission

[69] 2 housings

[70] 3 first wave

[71] 4 second wave

[72] 5 electric motor

[73] 6 first sprocket

[74] 7 second sprocket

[75] 8 third sprocket

[76] 9 fourth sprocket

[77] 10 fifth sprocket

[78] 11 sixth sprocket

[79] 12 seventh sprocket

[80] 13 first end

[81] 14 second end

[82] 15 first freewheel [83] 16 second freewheel

[84] 17 frames

[85] 18 crank

[86] 19 pedals

[87] 20 rear sprocket

[88] 21 chain

[89] 22 ball bearings

[90] 23 first hollow shaft

[91] 24 second hollow shaft

[92] 25 first ball bearing

[93] 26 second ball bearing

[94] 27 first transmission chain

[95] 28 second transmission chain

[96] 29 third transmission chain

[97] 30 recording

[98] 31 WeIIe

[99] ni Number of teeth of the first sprocket

[100] n ₂ Number of teeth of the second sprocket

[101] n ₃ Number of teeth of the third sprocket

[102] n ₄ Number of teeth of the fourth sprocket

[103] n ₅ Number of teeth of the fifth sprocket

[104] n ₆ Number of teeth of the sixth sprocket

Claims

[Claim 1] Chain transmission for translating a motor torque of an electric motor (5), comprising:

- Three translation stages, wherein the first gear stage by a first sprocket (6) and a fourth sprocket (9), the second gear stage by a second sprocket (7) and a fifth (10) sprocket and the third gear stage by a third sprocket ( 8) and a sixth ring gear (11) is formed;

- The first sprocket (6), the second sprocket (7) and the third sprocket (8) are arranged on a first shaft (3) and the fourth sprocket (9), the fifth sprocket (10) and the sixth sprocket (11 ) are arranged on a second shaft (4);

- To transmit the torque, a transmission chain (27, 28, 29) is provided in each gear ratio, wherein the first shaft (3) as the output shaft of the electric motor (5) and the second shaft (4) is designed as a bottom bracket of a vehicle.

Claim 2 chain transmission according to claim 1, wherein the transmission ratio of the chain transmission (1) is less than 1.

[Claim 3] A chain transmission according to claim 2, wherein the first ring gear (6) has a number ^ of teeth, the second one

Sprocket (7) a number n ₂ , the third sprocket (8) a number n ₃ , the fourth sprocket (9) a number n ₄ , the fifth sprocket (10) a

Number n ₅ and the sixth ring gear (11) has a number n ₆ , wherein n ₃ <n ₆ and n ₅ <n ₂ .

Claim 4 chain transmission according to claim 3, wherein

U ₁ = n ₃ = n ₅ and n ₂ = n ₄ = n ₆ .

[Claim 5] Chain transmission according to one of claims 1 to 4, wherein as transmission chains (27, 28, 29) three identical chains are provided.

Claim 6 chain gear according to one of claims 1 to 4, wherein the

Transmission chains (27, 28) of the first and the second translation stages has lower strengths than the transmission chain (29) of the third gear ratio.

[Claim 7] Chain transmission according to one of claims 1 to 6, wherein the second sprocket (7) and the third sprocket (8) on a common first hollow shaft (23) are arranged, whose axis of rotation coincides with the axis of rotation of the first shaft (3) ,

[Claim 8] The chain transmission according to one of claims 1 to 6, wherein the first shaft (3) is divided and has a first portion and a second portion which are separate from each other but rotatable about the same axis, the first portion having is connected to the electric motor (5) and wherein the first sprocket (6) on the first region and the second sprocket (7) and the third sprocket (8) on the second region of the first shaft (3) are arranged.

[Claim 9] Chain transmission according to one of claims 1 to 8, wherein the fourth sprocket (8) and the fifth sprocket (9) are arranged on a common second hollow shaft (24) whose axis of rotation coincides with the axis of rotation of the second shaft (4) ,

[Claim 10] Chain transmission according to one of claims 1 to 9, wherein the sixth sprocket (11) has a first freewheel (15).

[Claim 11] Chain transmission according to one of claims 2 to 10, wherein the transmission ratio of the chain transmission (1) is at least 1: 100 and at most 1:25.

[Claim 12] chain transmission according to claim 11, wherein the transmission ratio of the chain transmission (1) is at least 1:50 and at most 1:40.

[Claim 13] The vehicle having a chain transmission according to any one of claims 1 to 12, wherein the vehicle has both a pedal drive and an electric motor drive, wherein the output shaft of the electric motor and the output shaft of the pedal drive by the chain transmission (1) are coupled together.

The vehicle of claim 13, wherein a seventh ring gear (12) is disposed on the second shaft (4) connected by a chain (21) to a rear sprocket (20) of the vehicle.

[Claim 15] The vehicle of claim 14, wherein the rear sprocket (20) is associated with a rear wheel of the vehicle.

[Claim 16] Vehicle according to claim 14, the rear sprocket (20) is associated with a differential gear of the vehicle.

[Claim 17] Vehicle according to one of claims 14 to 16, wherein the seventh ring gear (12) has a second freewheel (16).

[Claim 18] Vehicle according to one of claims 13 to 17, wherein the chain transmission (1) is arranged in a housing (2) which is connected to a frame (17) of the vehicle.

A vehicle according to claim 18, wherein the housing (2) with the chain transmission (1) forms an integral part of the frame (17) of the vehicle.

[Claim 20] Vehicle according to one of claims 13 to 19, wherein the vehicle is designed as a two-wheeled vehicle.

[Claim 21] Vehicle according to one of claims 13 to 19, wherein the vehicle is designed as a tricycle.

[Claim 22] Vehicle according to one of claims 13 to 19, wherein the vehicle is designed as a four-wheel.

[Claim 23] Vehicle according to one of claims 14 to 22, wherein a freewheel (38) is provided such that the electric motor (5) can drive the seventh ring gear, without the pedals rotate with.

[Claim 24] The vehicle of claim 23, wherein the freewheel (38) is lockable.

[Claim 25] The vehicle of claim 23, wherein the direction of the freewheel (38) is switchable.

[Claim 26] A method of translating engine torque in a vehicle having an electric motor drive and a pedal drive, the method comprising the steps of:

- First translation of the torque from a first sprocket (6) by means of a first gear chain (27) on a fourth sprocket (9);

- Second translation of the torque from a second sprocket (7) by means of a second gear chain (28) on a fifth sprocket (10);

- third transmission of the torque from a third sprocket (8) by means of a third gear chain (29) on a sixth sprocket (11), wherein the sixth sprocket is connected to a bottom bracket (4) of the vehicle;

- Transmission of the torque from the bottom bracket (4) by means of a chain (21) on a rear wheel of the vehicle associated rear sprocket (20).

[Claim 27] The method of claim 26, wherein a pedal torque is applied to the bottom bracket shaft (4) in addition to the translated motor torque.

[Claim 28] The method of claim 26 or 27, wherein the first compilation, the second compilation, and the third compilation occur at a gear ratio that is less than one.

[Claim 29] Method according to one of claims 26 to 28, wherein the transmission ratio of the chain transmission (1) at least 1: 100 and at most 1:25 is selected.

[Claim 30] The method of claim 29, wherein the gear ratio of the chain transmission (1) at least 1:50 and at most 1:40 is selected.