WO2012066124A1

WO2012066124A1 - Drive unit

Info

Publication number: WO2012066124A1
Application number: PCT/EP2011/070463
Authority: WO
Inventors: Michael Schmitz; Christoph Lermen
Original assignee: Pinion Gmbh
Priority date: 2010-11-19
Filing date: 2011-11-18
Publication date: 2012-05-24
Also published as: DE102010051727A1

Abstract

The invention relates to a drive unit (30) for a vehicle driven by muscle power, comprising a first shaft (52, 60), on which a plurality of gear wheels (53-59, 62, 76, 78) are mounted, and a second shaft (32, 34), on which a corresponding plurality of gear wheels (45-51, 64, 80, 82) are mounted, which mesh with the gear wheels (53-59, 62, 76, 78) of the first shaft (52, 60), wherein one of the gearbox shafts (32, 34, 52, 60) is connected, or can be connected, to a motor shaft (22) of an electric motor (20) so as to couple a torque into the gearbox (10) or out of the gearbox (10).

Description

drive unit

The present invention relates to a drive unit for a muscle-powered vehicle according to the preamble of claim 1.

The present invention further relates to a bicycle with such a drive unit.

Such drive units are used to drive powered by muscle power vehicles and to overdrive or underpin the driving force accordingly. From DE 10 2008 064514 AI a transmission unit for a muscle powered vehicle is known in which a through shaft, which is connected with cranks for driving the vehicle and a countershaft are provided, wherein on the countershaft switchable idler gears are mounted, the gear wheels of the through shaft and with gears of an output shaft each form a partial transmission, wherein the output shaft is arranged coaxially with the through shaft. By such a gear unit can be realized up to 18 gears. A disadvantage of this transmission unit is that no auxiliary motor is provided to support the muscle drive.

Furthermore, it is known to equip bicycles with auxiliary motors, which are arranged as a hub motor in the front wheel or the rear hub. Such hub motors are usually offered in combination with derailleurs. Especially with rear wheel motors, the combination with a hub gear is complicated, since the engine takes up a large amount of space. A disadvantage of the hub motors u.a. the large weight and the unfavorable weight distribution, since the proportion of unsprung mass of the bicycle in Vorderbzw. Rear wheel increases. Since such hub motors are directly connected to the impeller, they must operate in slow speed ranges. Slow-speed electric motors that provide a relatively high torque are usually very large, have a high weight, which can reach up to 4.5 kg, and have a low efficiency. For weight and space reasons such hub motors are rather disadvantageous.

To counteract this disadvantage, such auxiliary motors are also installed as a mid-engine in the area of the bottom bracket, in which the force is transmitted directly to the chain. The disadvantage here is that the chain in the bottom bracket area can not be overturned by a sprocket on the other, whereby the use of a derailleur is limited. When using rear wheel cassettes or ordinary hub gears in connection with such middle engines, however, only a gear number of up to ten gears can be realized. Against this background, it is the object of the present invention to provide a drive unit that combines muscle strength and driving force of an auxiliary engine and at the same time has a low weight at a usual high number of gears and a usual spread.

This object is achieved in the drive unit mentioned above in that one of the transmission shafts connected to a motor shaft of an electric machine or is connectable to a torque in the transmission or decoupled from the transmission.

This object is further achieved by a bicycle with such a drive unit.

In the most general form of the invention, a drive unit for a powered by muscle power vehicle is provided with a first shaft on which a plurality of gears is mounted, and a second shaft on which a corresponding plurality of gears is mounted, wherein a the waves is connected or connectable to a motor shaft of an electrical machine.

Advantage of the invention is that the electric machine connected to one of the transmission shafts or is connectable and thus in a compact design, an electric traction can be introduced into the transmission and can be dispensed with prone attachments. By connecting the electric drive with a multi-stage gear unit and the connection of the electric drive with one of the transmission shafts, a combination with each chain or hub circuit is possible and any number of switchable gears feasible.

The object of the present invention is thus completely solved. Preferably, a drive unit for a muscle-powered vehicle is provided with a drive shaft which is connectable to drive the vehicle with a drive source, a countershaft on which a Mahrzahl of gears is mounted, and an output shaft, wherein the at the Countershaft mounted gears each mesh with a gear which is mounted on the drive shaft or the output shaft, wherein one of the transmission shafts connected to an engine shaft of an electric machine or is connectable to couple a torque in the transmission on or out of the transmission.

Preferably, the transmission shaft is the drive shaft.

Thereby, the electric machine can be operated regardless of the driving speed in a narrow speed range, since the electric machine drives at the input of the transmission and thus can always be operated near the optimum operating point. Through this narrow operating range in which the electric machine is operated, a better efficiency can be achieved and a more compact design of the electric machine can be realized.

Alternatively, it is preferred if the transmission shaft is the countershaft.

Characterized the transmitted engine power is transmitted only via a pair of wheels, whereby the friction losses are reduced and can be used by the translation of the pair of wheels a fast-running engine with low weight and small size. Furthermore, the coupling of the electric machine to the countershaft allows a recuperation, so a braking force recovery, in overrun operation of the vehicle.

Alternatively, it is preferred if the transmission shaft is the output shaft. As a result, the engine power is not reduced by friction losses in the transmission. Furthermore, a recuperation is possible because the engine is connected to the output shaft, which runs along the sprocket.

Preferably, a plurality of gears is mounted on the output shaft, which form a partial transmission with gears of the countershaft, wherein the gears of the countershaft are designed as loose wheels, which are rotatably connected by means of switching means with the countershaft. As a result, a multi-stage partial transmission can be realized in a simple and compact design.

Preferably, a plurality of gears is mounted on the drive shaft, which form a partial transmission with gears of the countershaft, wherein the gears are designed as loose wheels, which are rotatably connected by means of switching means with the countershaft. The fact that the second partial transmission is designed as a change gear, increases the overall gear ratio of the drive unit.

Preferably, the switching means switchable freewheels, which are actuated by means of a camshaft mounted in the form of a hollow shaft countershaft. As a result, the corresponding partial transmission can be realized in a compact design as a power shift transmission.

Preferably, two camshafts for switching the two partial transmissions are provided, wherein the second camshaft is actuated by the first camshaft mounted in the countershaft by means of a driver. As a result, the transmission unit can be switched comfortably via a single shift lever.

Preferably, the electric machine via a reduction gear with the respective transmission shaft is connectable. As a result, high-speed electrical machines can be used, which require less space compared to low-speed electrical machines and have a lower weight. Furthermore, it is preferred if the electric machine by means of a clutch, in particular a clutch or a switchable freewheel with the respective transmission shaft is connectable. As a result, the electric machine can be mechanically coupled to the transmission or decoupled from the transmission, so that the motor shaft of the electric machine does not have to be rotated in the pure muscle drive.

Furthermore, it is preferred if the reduction gear has at least one, preferably two or more planetary gear. As a result, the reduction gear can be realized with a high reduction ratio in a compact design.

Furthermore, it is preferred if the motor shaft of the electric machine with one of the gears of the transmission shafts rotatably connected. As a result, the coupling and the decoupling of the torque is simple and compact feasible, since an existing gear can be used.

Further, it is preferred if the motor shaft by means of a ratchet wheel which is mounted on the transmission shaft, at least in a rotational direction rotatably connected to the transmission shaft is connectable. As a result, the torque can be transmitted to the transmission shaft in a simple design.

It is preferred if the ratchet by means of a freewheel, in particular a switchable freewheel, in a drive direction with the transmission shaft is connectable. As a result, the electric machine can be connected to the transmission shaft in the drive direction and automatically switches to freewheeling operation as soon as the transmission shaft has a higher rotational speed than the electric machine.

Furthermore, it is preferred if the ratchet by means of a switchable freewheel in a direction opposite to the drive direction rotatably with the transmission shaft is connectable. As a result, it is possible to switch from the drive mode to the recuperation mode with simple means.

Furthermore, it is preferred if the switchable freewheels are actuated by means of a camshaft arranged in the transmission shaft. As a result, the switchable freewheels of the switching wheel can be switched in a simple and compact design, whereby a simple switching from drive to recuperation is possible.

It is preferred if the camshaft for switching the freewheels is rotatable relative to the transmission shaft, wherein the camshaft by means of a speed superposition gear, in particular by means of second planetary gear, is rotatable relative to the transmission shaft. This makes it possible to realize a particularly compact construction in the axial direction.

In general, it is preferred if the motor shaft of the electric machine is arranged parallel to the transmission shafts. As a result, the motor shaft of the electric machine can be connected in a simple construction by means of an intermediate gear or a spur gear with the corresponding shaft of the first or the second sub-transmission.

Alternatively, it is preferred that the shaft of the electric machine is arranged at an angle of 90 ° to the transmission shafts. As a result, the electric machine can be mounted in a tube of the bicycle frame, whereby a total of a compact design can be realized.

It is preferred if the motor shaft of the electric machine by means of a crown gear or a bevel gear with one of the transmission shafts is connectable. As a result, an angled arrangement of the motor shaft of the electric machine to one of the shafts of the partial transmissions can be realized in a simple design. Overall, it is preferred if the shaft of the electric machine is formed integrally with one of the transmission shafts. This makes it possible to realize a particularly compact and lightweight design, because the corresponding transmission shaft is used twice.

In general, it is preferred that in the switching operation of a gear in the next gear initially the pawls of the corresponding idler gears in an intermediate state are simultaneously pivoted radially outward. Thereby, a power shift transmission can be realized, whereby at the same time the safety is increased before a spin of the crank in the event of a ratchet fracture.

It is understood that the features mentioned above and those yet to be explained not only in the particular combination given, but also in other combinations or alone, without departing from the scope of the present invention.

Embodiments of the invention are illustrated in the drawings and are explained in more detail in the following description. Show it:

Fig. 1 is a side view of a bicycle frame with a multi-speed transmission and an electric drive;

Fig. 2a-c is a schematic representation of an electrical machine and a

Coupling by means of clutch and reduction gear;

Fig. 3 is a circuit diagram of a drive unit with multi-speed transmission and electric drive; 4 shows a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, which is coupled to the drive shaft.

5 shows a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, which is coupled to the drive shaft.

Fig. 6 is a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, which is coupled to the output shaft of the multi-speed transmission;

Fig. 7 is a circuit diagram of a drive unit with a multi-speed transmission and electric drive, which is coupled to the output shaft of the multi-speed transmission;

8 is a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, which is coupled to the countershaft.

9 is a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, which is coupled to the countershaft.

10 is a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, in which the motor shaft of the electric drive is arranged orthogonal to the transmission shafts and is coupled via a crown wheel on the countershaft.

11 is a circuit diagram of a drive unit with a multi-speed transmission and an electric drive, wherein the motor shaft of the electric see drive is arranged orthogonal to the transmission shafts and is connected via a bevel gear to the output shaft; and

Fig. 12 is a schematic sectional view of a shaft with one in both

Direction of rotation connectable idler gear in the axial direction.

In Fig. 1, a transmission unit for a muscle powered vehicle is shown and generally designated 10.

Fig. 1 shows a side view of a bicycle frame 12 having a gear housing 14 in which the transmission unit 10 is received. The gear unit 10 is schematically indicated in this illustration and is designed as a compact unit, which is preferably arranged in a gear cage, not shown here. The gear unit 10 is described here by way of example for use in a two-wheeler, although the use is also possible in other powered by muscle power vehicles.

The gear unit 10, the gear housing 14 together with pedal cranks 16 and 16 ', a multi-speed transmission 18. The bicycle frame 12 has an electric drive 20 which is connected to the multi-speed transmission 18 to the vehicle in addition to the drive via the cranks 16, 16 'to drive. The electric drive 20 is connected to an electrical energy source 21, which supplies the electrical drive 20 with electrical energy. The energy source 21 is preferably designed as an accumulator 21.

In the figures 2a to 2c, the electric drive 20 is shown schematically with different coupling possibilities.

Fig. 2a shows the electric drive 20 having the motor shaft 22 which is connected to a gear 24. The gear 24 serves to the torque generated by the electric drive 20, via the motor shaft 22 on the gear 24 is transmitted to other gears of the transmission unit 10 to transmit. As electrical drive 20 is any electrical machine can be used, especially DC motors with and without Kommutatorschleifkontakten.

In Fig. 2b, the electric drive 20 is shown with a reduction gear 26. The gear 24 is connected via the reduction gear 26 to the motor shaft 22. The reduction gear 26 is formed by two successively connected planetary gear, wherein the motor shaft 22 is connected to a sun gear of the first planetary gear. As output, a planetary carrier of the first planetary gear is connected to a sun gear of the second planetary gear. The gear 24 is connected to a planet carrier of the second planetary gear. Ring gears of the planetary gear are rotatably mounted or fixed to the housing. As a result, the speed of the electric drive 20 can be reduced by simple means, whereby the electric drive can be designed for a higher rated speed range, and thereby greatly reducing the weight and size of the electric drive 20.

In Fig. 2c, the electric drive 20 is shown with the reduction gear 26, wherein the shaft 22 has a coupling 28 to releasably connect the electric drive 20 with the reduction gear 26. The clutch 28 may be formed as a switchable clutch or as a switchable freewheel, in particular as a sprag freewheel, as an axial overrunning clutch with frontal toothing, as a pawl freewheel or as a switchable friction clutch.

The clutch 28 may be disposed at any point in the power flow between the electric drive 20 and the transmission unit 10. The arrangement between the electric drive 20 and the reduction stage 26 is advantageous because the applied torque is low and thus the clutch can be dimensioned smaller. The disadvantage here, however, is that the translation stage 26 is also rotated and accelerated in muscle power, thereby increasing the driving resistance. If the clutch 28 further back in Power flow between the electric drive 20 and the transmission unit 10 is arranged, so for example. Between an intermediate and a gear wheel of the transmission unit 10, fewer gears are rotated, whereby the driving resistance is reduced. In this case, however, the clutch 28 must transmit a larger torque and therefore be sized larger. Furthermore, electric bicycles may only be electrically driven up to a certain maximum speed, but it must be possible to drive faster with muscle power. For this, the electric drive 20 must be decoupled from the transmission unit 10.

In principle, a distinction can be made in electric drive between a low-speed concept and a high-speed concept. In the low speed concept, the rated speed range of the electric drive is approximately within the operating range of the transmission and may be engaged with the transmission directly or with a low reduction ratio stage. Electric drives, which operate in a low speed range and apply a high torque, are relatively large and have a large weight and have some poor efficiency. Advantage of this concept, however, is that it can be dispensed with a complex reduction stage in order to reduce the engine speed to a corresponding transmission speed. In the event that the electric drive 20 is to be operated regeneratively for energy recovery, only the flywheel mass of the engine must be accelerated and not the flywheel of the reduction stage.

In the high speed concept, the rated speed range is well above the speed range of the transmission. These motors are relatively small and lightweight with a high power density, which contributes to a compact design of the entire drive unit. The high engine speed must be reduced by the reduction gear 26 to the speed range of the transmission. In a multi-stage planetary gear, as shown at 26, a reduction factor of 25 is feasible. Disadvantage of this embodiment, in addition to the complex translation stage, the behavior in generator operation, which is relatively cumbersome and can even lead to self-locking. For large translations Zungsverhältnissen the reduction unit 26, the electric drive 20 can not rotate due to the motor resistance and the friction of the reduction stage 26. Another disadvantage of the fast rotating engines and gear stages is increased noise.

In Fig. 3, a drive unit for driving a vehicle is shown and generally designated 30.

The drive unit 30 has the gear unit 10 and the electric drive 20.

The transmission unit 10 has a drive shaft 32 and an output shaft 34. The drive shaft 32 is formed as a through shaft and forms the input shaft 32 of the transmission unit 10. The output shaft 34 is formed as a hollow shaft. The drive shaft 32 and the output shaft 34 are arranged coaxially with each other. The output shaft 34 is rotatably connected to a chainring 36, which forms an output member of the transmission unit 10. The drive shaft 32 is connected on opposite sides with the cranks 16, 16 'to drive the drive shaft 32.

On the drive shaft 32, a first gear 38 is mounted, which is in engagement with an intermediate gear 40. The intermediate gear 40 is engaged with the gear 24, which is connected via the motor shaft 22 to the electric drive 20. The gear 24 is thus rotatably connected via the intermediate gear 40 and the gear 38 to the drive shaft 32. As a result, the drive shaft 32 can be driven by the electric drive 20.

The transmission unit 10 has a first partial transmission 42 and a second partial transmission 44. On the drive shaft 32, a plurality of drive wheels 46, 47, 48, 49, 50 are mounted. The drive shaft 32 forms the input shaft of the first partial transmission 42. The first partial transmission 42 has a countershaft 52, on which driven wheels 54, 55, 56, 57, 58 are mounted. The driven wheels 54 to 58 are designed as loose wheels.

The driven wheels 54 to 58 are connected by means of switching means 61 with the countershaft 52. The driven wheels 54 to 58 and the drive wheels 46 to 50 form pairs of wheels having different ratios, so that by selectively connecting the driven wheels 54 to 58 with the countershaft 52 different gear ratios can be realized.

The second partial transmission 44 has an input shaft 60 and the output shaft 34. The input shaft 60 is formed integrally with the countershaft 52. In an alternative embodiment, the input shaft 60 may be formed separately from the countershaft 52 and rotatably connected via a gear with the countershaft 52.

On the input shaft 60, a gear 62 is mounted. On the output shaft 35, which forms both the output shaft of the second partial transmission 44 and the output shaft of the transmission unit 10, a gear 64 is mounted. The gears 62 and 64 form a Konstantenradsatz and connect the input shaft 60 to the output shaft 34 rotatably. In one embodiment of the transmission unit 10, the second partial transmission 44 has a plurality of pairs of wheels which have different ratios. In this case, preferably, the gears which are mounted on the input shaft 60, designed as idler gears, so that by selectively connecting the gears to the input shaft 60 different gear ratios of the second sub-transmission 44 can be realized. In a particular embodiment, the first partial transmission 42 may be formed by a Konstantenradsatz.

The transmission unit 10 shown in Fig. 3 has five different gear ratios, which can be realized by the pairs of wheels of the first partial transmission 42. Since the electric drive 20 is rotatably connected to the drive shaft 32, drives the electric drive 20 on the same drive shaft 32, the transmission unit 10, as the cyclist on the cranks 16, 16 '. Characterized in that the electric drive 20 is connected to the drive shaft 32 before the transmission unit 10, the electric drive 20 can be operated independently of the driving speed in a narrow speed range with a speed of about 70-100 U / min. The electric drive 20 can thus always be operated close to the optimum operating point, whereby an improved efficiency and a compact design can be realized. The motor shaft 22 of the electric drive 20 is arranged parallel to the transmission shafts 32, 34, 52, 60 in this embodiment. As an alternative to the parallel offset arrangement of the electric drive 20, the electric drive 20 may also be arranged coaxially with the drive shaft 32, in particular between the gears 46 to 50, wherein the drive shaft 32 in this embodiment forms the motor shaft 22 and thus the rotor of the electric drive 20th

In another embodiment, the gear 24 may mesh directly with the gear 38. Alternatively, the intermediate gear 40 may be formed as a traction means or as a chain. In order to achieve a desired center distance between the motor shaft 22 and the transmission shaft, a pair of gears from the gear 24 and the intermediate gear 40 can be used with a large pitch diameter.

4, an alternative embodiment of the drive unit 30 is shown. The same elements are designated by the same reference numerals, with only the differences being explained here.

On the drive shaft 32, the drive wheels 45 to 51 are mounted and on the countershaft 52, the driven wheels 53 to 59 are mounted. The drive gears 45 to 51 form with the driven wheels 53 to 59 pairs of wheels having different ratios. The driven wheels 53 to 59 are designed as loose wheels and by means of switching means 61 with the countershaft 52nd rotatably connected. the countershaft 52 is formed as a hollow shaft in which a camshaft 66 is rotatably mounted. The camshaft 66 has different cams, by means of which the switching means 61 of the idler gears 53 to 59 can be actuated to selectively connect the idler gears 53 to 59 with the countershaft 52 rotationally fixed. The camshaft 66 is connected via a speed superposition gear 68 with the countershaft 52. The speed superposition gear 68 is arranged coaxially with the countershaft 52. The speed superposition gear is formed by a first planetary gear 70 and a second planetary gear 72. The first planetary gear 70 has a traction pulley 74, which is connected to a ring gear of the planetary gear 70. The speed superposition gear 68 is configured to rotate the camshaft 66 in synchronism with the countershaft 52 and to transmit rotation of the traction sheave 74 as a relative movement of the camshaft 66 to the countershaft 52 to the camshaft 66. This allows the idler gears 53 to 59 are connected by the relative movement of the camshaft 66 to the countershaft 52 with the countershaft 52, whereby selectively different gears or gear ratios can be realized. The idler gears 53 to 59 are rotatably connected by means of switchable freewheels 61 in a drive direction with the countershaft 52.

The gear 24 is rotatably connected via the intermediate gear 40 with the driven wheel 59. Thereby, the rotation of the electric drive 20 can be transmitted to the driven wheel 59. If the driven wheel 59 is not rotatably connected to the countershaft 52, the driven wheel 59 drives the drive wheel 51 of the drive shaft 32, so that a torque is transmitted from the electric drive 20 to the drive shaft 32. As a result, the electric drive is connected to the drive shaft 32 and the gear unit 10 upstream. An electric traction can thus be transmitted to the drive shaft 32.

It is understood that the gear 24 can also be directly engaged with the driven wheel 59 in engagement. It is understood that the electric drive 20 may be arranged coaxially with the drive shaft 32. The drive shaft 32 may be integrally connected to the motor shaft 22 and the rotor of the electrical form drive 20. The electric drive 20 may also be arranged between the drive wheels 45 to 51. Advantage of the embodiment shown in Fig. 4 is that the driven wheel 59 and the drive wheel 51 are used both to initiate the electric traction and as a pair of wheels of the first sub-transmission. Furthermore, the moments of the electric drive 20 and the muscle drive are superimposed by the rotationally fixed connection of the drive shaft 32 with the motor shaft 22.

The switchable freewheels 61 preferably have pawls which engage in internal gears of the idler gears 53-59 in order to connect them rotatably with the countershaft 52. The internal camshaft 66 moves the pawls inwardly to disengage them from the internal teeth. The pawls are biased by a spring which moves the pawls outwardly to engage the pawls with the internal teeth. When switching, it is preferred if the pawls are pivoted simultaneously from two successive gear stages in an intermediate state radially outward. Since the respective higher gear stage has a smaller gear ratio, engage the ratchets of the higher gear in the teeth and drive the countershaft at a rotational speed which is greater than the rotational speed of the idler gear of the lower gear. The pawl of the lower gear then changes to the freewheel, so that the higher gear is engaged immediately. In a further step, the lower gear pawl is actuated, ie moved inwards, in order to fully engage the higher gear. Thereby, a power shift transmission can be realized, whereby an idle state can be avoided and the safety of the driver can be increased.

5 shows a further embodiment of the drive unit 30, in which the electric drive 20 of the gear unit 10 is connected upstream. Reference is made to Figures 3 and 4, wherein like elements are designated by like reference numerals and only the differences are explained here. The first partial transmission 42 has the drive wheels 45 to 50 and the driven wheels 53 to 58, which form pairs of wheels with different ratios. The driven wheels 53 to 58 are designed as loose wheels and connectable by means of the switching means 61 with the countershaft 52. The switching means 61 are selectively actuated by means of the arranged in the countershaft 52 camshaft 66. The camshaft 66 is connected to the speed superposition gear 68 to rotate in synchronism with the countershaft 52 and to be rotated to shift from one gear to another relative to the countershaft 52.

The second partial transmission 44 has the input shaft 60, are mounted on the drive wheels 76, 78. The drive wheels 76, 78 mesh with driven wheels 80, 82 which are mounted on the output shaft 34. The drive wheels 76, 78 are designed as loose wheels and by means of switching means 79 with the input shaft 60 rotatably connected. The intermeshing drive wheels 76, 78 and driven wheels 80, 82 form pairs of wheels having different ratios. The switching means 79, which connect the drive wheels 76, 78 to the input shaft 60, are selectively actuatable by a cam shaft 84 rotatably mounted in the input shaft 60. By selectively connecting the drive wheels 76, 78 with the input shaft 60 different gear stages of the second sub-transmission 44 are realized. Characterized in that the first partial transmission 42 and the second partial transmission 44 are connected in series, the gear stages of the two partial transmissions 42, 44 multiply to a total number of gears of the gear unit 10. In this case, twelve gear ratios are realized.

The camshaft 84, like the camshaft 66, rotates in synchronism with the input shaft 60 to maintain a set shift state and is rotated relative to the input shaft 60 to change the shifting state of the second subtransmission 44. The camshaft 84 is connected via a driver 86 with the camshaft 66. The cam 86 transmits relative rotation to the camshaft 84 when the highest gear of the first sub-transmission 42 is reached to switch from the sixth gear in this case to the following seventh gear. The driver 86 rotates in this case, the camshaft 84 so that is switched from the first gear of the second partial transmission 44 in the second gear. At the same time, by rotating the camshaft 66, the first partial transmission 42 is shifted from the sixth gear to the first gear. As a result, both partial transmissions 42, 44 can be switched by actuating the traction sheave 74 of the speed superposition gear 68.

The gear 24 of the electric drive 20 is rotatably connected via the intermediate gear 40 with the drive wheel 45. As a result, an electric traction can be introduced via the drive shaft 32 into the transmission unit 10. The advantage here is that the drive wheel 45 is both part of a pair of wheels of the first sub-transmission 42 and also serves to initiate the electrical traction of the electric drive 20.

It is understood that the electric drive can also be arranged coaxially with the drive shaft 32, wherein preferably the motor shaft 22 is integrally formed with the drive shaft 32 and forms the rotor of the electric drive 20.

In general, when electrical traction is introduced via the input shaft during downshifting under load, the electric drive must be interrupted to improve the shifting performance.

In Fig. 6, the drive unit 30 is shown, in which the electrical traction of the electric drive 20 is introduced via the output shaft 34 in the transmission unit 10. The transmission unit 10 in Fig. 6 is identical to the transmission unit 10 shown in Fig. 5. The same elements are designated by the same reference numerals, wherein only the differences are shown here.

The gear 24 is rotatably connected via the intermediate gear 40 with the driven wheel 78. As a result, via the intermediate gear 40 and the pair of wheels, which is formed by the drive wheel 78 and the driven wheel 82, a rotationally fixed Connection formed between the electric drive 20 and the output shaft 34. The drive wheel 78 is connected via a switchable freewheel 79 with the input shaft 60, so that the drive wheel 78 slides on the input shaft 60, provided that the rotation of the input shaft 60 is greater than that of the drive wheel 78th

To initiate the electric traction via the output shaft 34 is advantageous because the transmission unit 10 only has to transmit the muscular force of the driver, whereby the dimensioning of the transmission in terms of durability and weight can be reduced. Furthermore, a recuperation operation is easily possible because the electric drive 20 is connected to the output shaft 34 and the rotation of the output shaft 34 is not translated by the gear unit. However, a precondition for the recuperation operation is that the chainring 36 is connected in a rotationally fixed manner to the output shaft 34. Furthermore, it is necessary that in the rear wheel no freewheel is realized, so that the rear wheel is formed with a rigid gear.

Furthermore, the switching behavior of the transmission unit 10 is improved in this case, since the engine power in the power flow after the switchable freewheels 61, 79 is introduced and thus can be switched without power reduction of the engine.

In Fig. 6, the electric drive 20 is arranged parallel to the transmission shafts. The electric drive 20 may also be arranged coaxially with the output shaft 34 in a particular embodiment. It is preferred if the motor shaft 22 forms part of the output shaft 34 and in particular is formed integrally therewith.

In Fig. 7, another embodiment of the drive unit 30 is shown. The transmission unit 10 essentially corresponds to the transmission unit 10, which is shown in FIG. The same elements are designated by the same reference numerals, with only the differences are explained. The intermediate gear 40 meshes with a loose wheel 88 which is mounted by means of a bearing 90 on the input shaft 60. The idler gear 88 is connected via a coupling 92 with the drive wheel 78. The clutch 92 may be formed as an overrunning clutch or as a switchable coupling, which rotatably connects the idler gear 88 with the drive wheel 78 in one or both directions of rotation. Thereby, as in the embodiment of FIG. 6, the traction of the electric drive 20 via the drive wheel 78 and the driven wheel 82 are transmitted to the output shaft 34. Advantage of this embodiment is that the intermediate gear 40 and the gear 24 can be decoupled from the transmission unit 18, so that these gears do not rotate permanently in pure muscle operation. In this embodiment, furthermore, a separate coupling on or in the electric drive 20 can be dispensed with. The clutch 92 may, for example, be actuated via the camshaft 84 in the shaft 60.

In general, it is disadvantageous in this concept that the electric drive 20 can not be operated in a narrow speed range, but must cover the entire speed range.

The clutch 92 may generally be formed as a switchable clutch or switchable freewheel, in particular as a sprag freewheel, as an axial overrunning clutch with frontal toothing, as a pawl freewheel or as a switchable friction clutch.

In Fig. 8, the drive unit 30 is shown, in which the electrical traction on the countershaft 52 and the input shaft 60 of the second sub-transmission 44 is initiated. The transmission unit 10 essentially corresponds to the transmission unit from FIGS. 5 and 6. Identical elements are designated by the same reference numerals, with only the differences being shown here.

At the input shaft 60 of the second partial transmission 44, a freewheel 94 is mounted. The freewheel 94 blocks in a drive direction of the electrical see drive 20 with the input shaft 60 and slides on the input shaft 60 in an opposite direction of rotation. Thereby, the electric traction of the electric drive 20 is transmitted from the gear 24 via the intermediate gear 40 and the freewheel 94 to the countershaft 52 and the input shaft 60. If the input shaft 60 rotates faster than the freewheel 94, the freewheel 94 slides on the input shaft 60 and slides the input shaft 60 under the freewheel 94 by. The electric drive 20 is thus connected downstream of the freewheels 61 of the first partial transmission 42 and upstream of the freewheels 79 of the second partial transmission 44. As a result, the driving force of the electric drive 20 is advantageously not transmitted by the first partial transmission 42, but only by the second partial transmission 44, whereby the first partial transmission 42 can be dimensioned correspondingly smaller. Characterized in that the electric drive 20 is connected upstream of the second partial transmission 44, the speed range of the electric drive 20 may be correspondingly narrower dimensioned, whereby the design of the electric drive 20 may be smaller and lighter dimensions. In general, it is preferred if the traction of the electric drive 20 is introduced onto the countershaft 52 or the input shaft 60 in the axial direction as close as possible to the second partial transmission 44. It is particularly preferred that the traction of the electric drive is input to the input shaft 60 at an axial end of the input shaft 60, on an opposite side of the countershaft 52. Thereby, the torsional load of the countershaft 52 and the input shaft 60 is reduced, resulting in a longer life of the shaft.

During recuperation, when braking the vehicle, energy is recovered which can be used to charge the accumulator 21 or a battery in order to increase the range of the vehicle. For this purpose, a separate generator can be integrated into the system, which is installed in the drive unit 30 or is arranged as an external component on the vehicle and can be switched on separately comparable to a dynamo. In principle, it is possible to use the electric drive 20 in the braking phases of the vehicle as a generator. However, this is only possible if the electric drive 20 is coupled to the freewheels of the second partial transmission 44, since these do not allow co-rotation of the electric drive 20 during the rolling or braking phases, but change to the freewheel. Such a recuperation means of the electric drive 20 is thus possible when the motor shaft 22 is rotatably connected to the output shaft 34 or when the motor shaft 22 with the input shaft 60 and the countershaft 52 rotatably connected and the second part of the transmission 44 is formed as Konstantenradsatz. Further, it is necessary for the Rekuperationsbetrieb that the output shaft 34 is driven during coasting or braking, ie the bicycle must have a rigid or switchable rear hub, so that the chain or the output shaft 34 runs in overrun.

As described above, preferably between the electric drive 20 and the transmission unit 10, the clutch 28 is arranged so that the vehicle can be driven by pure muscle power without the engine rotates. In the case of recuperation, the clutch 28 must transmit the torque, ie the braking torque, in the opposite direction of rotation, so that a simple one-way clutch is unsuitable for recuperation operation. In a variant of the drive unit 30, therefore, the clutch 28 is designed as a switchable clutch, which is switched on during the drive or braking phase of the motor or rotatably connected and is open in the phases of muscle power operation.

Accordingly, recuperation without further measures is not possible with freewheel 94 according to FIG. 8.

9, an embodiment of the drive unit 30 with a switchable freewheel is shown schematically. The transmission unit 10 is substantially identical to the transmission unit 10 of Fig. 8. Like elements are designated by like reference numerals, and only the differences are explained here.

On the input shaft 60, a ratchet wheel 96 is mounted instead of the freewheel 94. The ratchet wheel 96 is formed as a loose wheel and by means of pawls 99th with the input shaft 60 rotatably connected. The pawls 99 are formed so that they connect the ratchet wheel 96 in one direction with the input shaft 60 rotatably and switch in an opposite direction in the freewheel. The ratchet wheel 96 has the pawls 99 which rotatably connect the ratchet wheel 96 to the input shaft 60 in the drive direction, and further pawls 101, which rotatably connect the ratchet wheel 96 in the opposite direction of rotation with the input shaft 60. The pawls 99, 101 are selectively actuated by a camshaft 98. The camshaft 98 is connected to a rotational speed superposition gear 100 configured to rotate the camshaft 98 in synchronism with the input shaft 60 and to rotate upon actuation of the speed superposition gear 100 relative to the input shaft 60. By the relative rotation of the camshaft 98, the pawls 99, 101 are selectively actuated, so that the corresponding locking direction of the ratchet wheel 96 can be changed. As a result, either the switching pawls 99, 101 arranged in the first direction or in the opposite direction can be switched. Thus, between a drive mode in which traction is introduced from the electric drive 20 into the transmission unit 10, be switched to a recuperation, in which torque is transferred to the electric drive 20 in overrun mode and converted accordingly into electrical energy. Alternatively, only the pawl 101 is actuated for recuperation by the camshaft 98, wherein the pawl 99 always remains swung and in drive mode, the input shaft 60 rotatably connects to the ratchet wheel 96 and switches in recuperation in the freewheel.

The speed superposition gear 100 is identical to the speed superimposed gear 68. The speed superposition gear 100 has a first planetary gear 102, the sun gear is connected to the camshaft 98 and the ring gear is connected to a tension pulley 104. The planet carrier of the planetary gear 102 is connected to a planet carrier of a second planetary gear 106, the sun gear is connected to the input shaft 60 and the ring gear is mounted fixed to the housing. By rotation of the traction sheave 104, the camshaft 98 is rotated relative to the input shaft 60, so that the pawls 99, 101 of the ratchet wheel 96 are switched. As a result, the reverse direction of the switching wheel 96 is reversible, which can be switched by the electric drive in the recuperation. The tension pulley 104 is preferably actuated by means of a Bowden cable. The traction sheave 104 is connected in a preferred embodiment with a Bowden cable of the brake system of the vehicle, so that the drive unit 30 is switched during each braking operation in the Rekuperatonsbetrieb.

The speed superposition gear 100 may be connected in an alternative embodiment with an actuator which is integrated into a control loop of the vehicle. In this case, the actuator may be formed as an electric motor, which is connected to the externally toothed traction sheave 104. This means that it is possible to automatically switch between driving mode and recuperation mode. The control loop of the vehicle preferably detects automatically whether the vehicle is in overrun mode. The speed superposition gear 100 may also be replaced by a corresponding actuator connected to both the input shaft 60 and the camshaft 98.

In an alternative embodiment, the ratchet wheel 96 may be supported in identical form on the output shaft 34.

Upon initiation of electric traction on the countershaft 52 or the input shaft 60 of the second subgear 44, the electric drive is interrupted for switching the second subgear 44.

In Fig. 10, an alternative embodiment of the drive unit 30 of Fig. 8 and 9 is shown schematically, in which the motor shaft 22 of the electric drive 20 is arranged orthogonal to the transmission shafts. The gear unit 10 is substantially identical to the transmission unit of FIG. 8 and 9. The same elements are designated by the same reference numerals, only the differences are explained here.

Instead of the freewheel 94, a crown gear 108 is connected to the input shaft 60 in the drive unit 30 in FIG. 10. The crown gear 108 is rotatably connected to the intermediate gear 40, which rotates about an axis orthogonal to the transmission shafts. The intermediate gear 40 is connected to the gear 24 of the electric drive 20, wherein the motor shaft 22 is aligned orthogonal to the transmission shafts. Due to the orthogonal arrangement of the motor shaft 22, the electric drive 20 can be installed in a tube of the frame 12, whereby the electric drive 20 can be installed to save space in the frame 12. The crown gear 108 may be rotatably connected to the input shaft 60.

In a preferred embodiment, the crown wheel 108 is connectable to the input shaft 60 by means of an overrunning clutch. In a particularly preferred embodiment, the crown gear 108 is formed as a ratchet and selectively connectable in both directions of rotation with the input shaft 60, as described in detail with respect to the ratchet wheel 96 to Fig. 9.

In Fig. 11, a further embodiment of the drive unit 30 is shown schematically, in which the motor shaft 22 is aligned orthogonal to the transmission shafts and the electric traction is introduced via the output shaft 34 in the transmission unit 10. The transmission unit 10 is substantially identical to the transmission unit 30 shown in FIG. 6. The same elements are designated by the same reference numerals, wherein only the differences are explained here.

The drive wheel 76 of the second partial transmission 44 is rotatably connected via a Kegelradpaarung 110 with the motor shaft 22. The bevel gear pairing 110 has a bevel gear 112, which is non-rotatably connected to the motor shaft 22, and a bevel gear 114 which is rotatably connected to the drive wheel 76. Due to the bevel gear pairing 110, the drive wheel 76 is connected to the motor shaft 22. that is orthogonal to the transmission shafts. As a result, as in the embodiment of FIG. 10, the electric drive 20 can be installed in a tube of the frame 12, for example in the down tube or in the seat tube.

In addition to the compact design of the bicycle, the electric drive 20 is protected from shocks and the weather when housed in a frame tube and the appearance of the bicycle is compact and sporty, since the electric drive 20 is not visible from the outside.

In Fig. 12, the drive wheel 78 is shown in a schematic sectional view in the axial direction with the pawls 99, 101.

The drive wheel 78 has an internal toothing 116, in which the pawls 99, 101 can engage to rotatably connect the drive wheel 78 with the input shaft 60 in the corresponding direction of rotation. In this case, the pawl 99 is aligned so that it rotatably connects the drive wheel 78 in the drive direction of the electric machine 20 with the input shaft 60. The pawl 101 is oriented to rotationally connect the drive wheel to the input shaft 60 in the opposite direction, the recuperation direction. The pawl 101 is pivotally supported on the input shaft 60 and has an inner portion 118 and an outer portion 120. The inner portion 118 is operable by the camshaft 98 such that the outer gate 120 engaging the inner teeth 116 is pivoted inwardly to disengage the pawl 101 from the inner teeth 116. In order to bring the pawl 101 with the internal teeth 116 into engagement, the camshaft 98 has a recess 122 into which the inner portion 118 of the resiliently biased pawl 101 pivots inwardly. As a result, the outer portion 120 pivots outwardly and engages in the internal toothing 116, whereby the input shaft 60 is rotatably connected to the drive wheel 78 in Rekuperationsrichtung. The pawl 99 for the drive direction is not actuated in this embodiment by the camshaft 98 and runs in recuperation in the freewheel with and connects the drive wheel 78 to the input shaft 60 in the drive direction rotationally fixed. Alternatively, the pawls 99, 101 may be actuated alternately by the camshaft 98 so that either the pawl 99 or the pawl 101 is swung out.

By means of the pawls 99, 101 shown in FIG. 12, a rotation into the recuperation mode is possible by rotation of the camshaft 98.

Claims

claims

A drive unit (30) for a muscle-powered vehicle, comprising a first shaft (52, 60) on which a plurality of gears (53-59, 62, 76, 78) is mounted, and a second shaft (32, 34) on which a corresponding plurality of gears (45 - 51, 64, 80, 82) is mounted, which mesh with the gears (53 - 59, 62, 76, 78) of the first shaft (52, 60), characterized in that one of the transmission shafts (32, 34, 52, 60) is connected or connectable to a motor shaft (22) of an electric machine (20) in order to input torque into the transmission (10) or out of the transmission (10). decouple.

2. Drive unit according to claim 1, characterized in that the drive unit (30) has a drive shaft (32) and an output shaft (34), wherein the first shaft (52, 60) as a countershaft (52, 60) is formed and the second Shaft (32, 34) forms the output shaft (34) or the input shaft (32), wherein on the countershaft (52, 60) mounted gears (53-59, 62, 76, 78) each with a gear (45-51 , 64, 80, 82) mounted on the drive shaft (32) or the output shaft (34).

3. Drive unit according to claim 2, characterized in that the transmission shaft is the drive shaft (32).

4. Drive unit according to claim 2, characterized in that the transmission shaft, the countershaft (52, 60).

5. Drive unit according to claim 2, characterized in that the transmission shaft is the output shaft (34).

6. Drive unit according to one of claims 2 to 5, characterized in that on the drive shaft (32) a plurality of gears (45 - 51) loaded gela- Gert is that with gears (53-59) of the countershaft (52, 60) form a partial transmission (42), wherein the gears (53-59) of the countershaft (52, 60) are designed as loose wheels, by means of switching (61 ) are rotatably connected to the countershaft (52, 60).

7. Drive unit according to one of claims 2 to 6, characterized in that on the output shaft (34) has a plurality of gears (64, 80, 82) is mounted, which with gears (62, 76, 78) of the countershaft (52, 60) form a partial transmission (44), wherein the gears (62, 76, 78) of the countershaft (52, 60) are designed as loose wheels and by means of switching means (79) with the countershaft (60) are rotatably connected.

8. Drive unit according to claim 6 or 7, characterized in that the switching means (61, 79) switchable freewheels (61) which are actuated by means of a in the form of a hollow shaft countershaft (52, 60) mounted camshaft (66, 84) ,

9. Drive unit according to one of claims 1 to 8, characterized in that the electric machine (20) via a reduction gear (26) with the respective transmission shaft (32, 34, 52, 60) is connectable.

10. Drive unit according to one of claims 1 to 9, characterized in that the electrical machine (20) by means of a clutch (28), in particular a clutch or a switchable freewheel with the respective transmission shaft (32, 34, 52, 60) is connectable ,

11. Drive unit according to one of claims 1 to 10, characterized in that the motor shaft (22) of the electric machine (20) with one of the gears (45-51, 53-59, 62, 64, 76, 78, 80, 82nd ) of the transmission shafts (32, 34, 52, 60) rotatably connected.

12. Drive unit according to one of claims 1 to 11, characterized in that the motor shaft (22) by means of a ratchet wheel (94, 96) which is mounted on one of the transmission shafts (34, 52, 60), at least in one direction of rotation with the transmission shaft (34, 52, 60) is connectable.

13. Drive unit according to claim 12, characterized in that the switching wheel (94, 96) by means of a freewheel (99), in particular a switchable freewheel (99), in a drive direction with the transmission shaft (34, 62, 60) is connectable.

14. Drive unit according to one of claim 12 or 13, characterized in that the switching wheel (94, 96) by means of a switchable freewheel (101) in a direction opposite to the drive direction rotationally fixed to the transmission shaft (34, 52, 60) is connectable.

15. Drive unit according to one of claims 13 or 14, characterized in that the switchable freewheels (99, 101) by means of a in the transmission shaft (34, 52, 60) arranged camshaft (98) are actuated.

16. Drive unit according to claim 15, characterized in that the camshaft (98) for switching the freewheels (99, 101) relative to the transmission shaft (34, 52, 60) is rotatable, wherein the camshaft (98) by means of a speed superposition gear (100 ), in particular by means of two planetary gear (102, 106), relative to the transmission shaft (34, 52, 60) is rotatable.

17. Drive unit according to one of claims 1 to 16, characterized in that the motor shaft (22) of the electric machine (20) is arranged parallel to the transmission shafts (32, 34, 52, 60).

18. Drive unit according to one of claims 1 to 16, characterized in that the motor shaft (22) of the electric machine (20) at an angle of 90 ° to the transmission shafts (32, 34, 52, 60) is arranged.

19. Drive unit according to one of claims 1 to 17, characterized in that the motor shaft (22) of the electric machine (20) integral with one of the transmission shafts (32, 34, 52, 60) is formed.

20. Bicycle (12) with a drive unit (30) according to one of claims 1 to 19.