DE102010051727A1 - drive unit - Google Patents

Abstract

The invention relates to a drive unit (30) for a vehicle powered by muscle power, comprising a first shaft (52, 60) on which a plurality of gearwheels (53-59, 62, 76, 78) is mounted and a second shaft ( 32, 34), on which a corresponding plurality of gear wheels (45-51, 64, 80, 82) is mounted, which mesh with the gear wheels (53-59, 62, 76, 78) of the first shaft (52, 60) , wherein one of the transmission shafts (32, 34, 52, 60) is connected or connectable to a motor shaft (22) of an electrical machine (20) in order to couple torque into the transmission (10) or out of the transmission (10) .

Description

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 serve to drive powered by muscle power vehicles and to overdrive or undercut the driving force accordingly.

From the DE 10 2008 064 514 A1 a transmission unit for a muscle-powered vehicle is known in which a through-shaft, which is connected to cranks for driving the vehicle and a countershaft are provided, wherein on the countershaft switchable idler gears are mounted with the gears 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 passage 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 region of the front and 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, as the proportion of unsprung mass of the bicycle in the front or 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 power 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.

In the case of the drive unit mentioned at the outset, this object is achieved in that one of the transmission shafts is connected or connectable to a motor shaft of an electric machine in order to switch on or off a torque in 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 muscle-powered 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 one of the waves with a motor shaft of an electrical machine is connected or connectable.

Advantage of the invention is that the electric machine is connected to one of the transmission shafts or 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 connectable to drive the vehicle to a drive source, a countershaft having a plurality of gears thereon and an output shaft, the gears supported on the countershaft each meshing with a gear which is mounted on the drive shaft or the output shaft, wherein one of the transmission shafts connected to a motor shaft of an electric machine or is connectable to connect a torque in the transmission on or out of the transmission.

Preferably, the transmission shaft is the drive shaft.

As a result, the electric machine can be operated in a narrow speed range, regardless of the driving speed, since the electric machine drives at the input of the transmission and thus can always be operated close to the optimum operating point. This narrow operating range, in which the electric machine is operated, can be 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.

As a result, 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 preferable 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 have switchable freewheels, which can be actuated by means of a camshaft mounted in the countershaft designed as a hollow shaft. 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 of the mounted in the countershaft first camshaft is actuated 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.

It is further preferred if the electric machine can be connected to the respective transmission shaft by means of a clutch, in particular a clutch or a switchable freewheel. 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 is 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 wheel by means of a switchable freewheel in a direction opposite to the drive direction rotationally fixed to the transmission shaft is connectable. By doing so leaves Switch with simple means of the drive operation in the recuperation.

Furthermore, it is preferred if the switchable freewheels can be 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 if 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 if, in the switching operation from a gear stage to the next gear stage, the pawls of the corresponding idler gears are first simultaneously pivoted radially outwards in an intermediate state. 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 below can be used not only in the particular combination given, but also in other combinations or in isolation, 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:

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

2a C is a schematic representation of an electric machine and a coupling by means of clutch and reduction gear;

3 a circuit diagram of a drive unit with multi-speed transmission and electric drive;

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

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

6 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;

7 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;

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

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

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

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

12 a schematic sectional view of a shaft with a connectable in both directions loose wheel in the axial direction.

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

1 shows a side view of a bicycle frame 12 that has a gearbox 14 in which the gear unit 10 is included. The gear unit 10 is indicated schematically in this illustration and is formed 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, but also the use in other powered by muscle power vehicles is possible.

The gear unit 10 , the gearbox 14 make up together with cranks 16 and 16 ' a multi-speed transmission 18 , The bicycle frame 12 has an electric drive 20 on that with the multi-speed transmission 18 connected to the vehicle in addition to the drive via the cranks 16 . 16 ' drive. The electric drive 20 is with an electrical energy source 21 connected to the electric drive 20 supplied with electrical energy. The energy source 21 is preferably as an accumulator 21 educated.

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

2a shows the electric drive 20 , the motor shaft 22 that has a gear 24 connected is. The gear 24 serves to that of the electric drive 20 generated torque that passes through the motor shaft 22 on the gear 24 is transmitted to other gears of the transmission unit 10 transferred to. As an electric drive 20 Any electrical machine can be used, in particular DC motors with and without Kommutatorschleifkontakten.

In 2 B is the electric drive 20 with a reduction gear 26 shown. The gear 24 is about the reduction gear 26 with the motor shaft 22 connected. 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, with simple means the speed of the electric drive 20 be reduced, whereby the electric drive can be designed for a higher rated speed range, and thereby reducing the weight and size of the electric drive 20 greatly reduce.

In 2c is the electric drive 20 with the reduction gear 26 shown, the shaft 22 a clutch 28 has to the electric drive 20 with the reduction gear 26 releasably connect. The coupling 28 can be designed 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 coupling 28 can be anywhere in the power flow between the electric drive 20 and the gear unit 10 be arranged. The arrangement between electric drive 20 and the reduction stage 26 is advantageous because the applied torque is low and thus the coupling can be dimensioned smaller. The disadvantage here, however, is that the translation stage 26 is also rotated in muscle power and accelerated, which increases the driving resistance. Unless the clutch 28 further back in the power flow between the electric drive 20 and the gear unit 10 is arranged, so for example. Between an idler and a gear wheel of the gear unit 10 , fewer gears are turned, whereby the driving resistance is reduced. In this case, however, the clutch must 28 transmit a larger torque and therefore be sized larger. Furthermore, electric bikes may only be electrically powered up to a certain maximum speed, but it must be possible to drive faster with muscle power. For this the electric drive has to be 20 from the gear unit 10 be decoupled.

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, to set the engine speed to a corresponding transmission speed. In the event that the electric drive 20 For energy recovery to be operated as a generator, 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 significantly 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 due to the reduction gear 26 be reduced to the speed range of the transmission. In a multi-stage planetary gear, as with 26 is shown is a reduction with the factor 25 realizable. 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 gear ratios of the reduction unit 26 can be the electric drive 20 due to the motor resistance and the friction of the reduction stage 26 do not turn. Another disadvantage of the fast rotating engines and gear stages is increased noise.

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

The drive unit 30 indicates the gear unit 10 and the electric drive 20 on.

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

At the drive shaft 32 is a first gear 38 stored, with an intermediate wheel 40 engaged. The intermediate wheel 40 is engaged with the gear 24 that over the motor shaft 22 with the electric drive 20 connected is. The gear 24 is thus on the intermediate 40 and the gear 38 rotatably with the drive shaft 32 connected. This is the drive shaft 32 through the electric drive 20 drivable.

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

The driven wheels 54 to 58 are by means of switching means 61 with the countershaft 52 connectable. The driven wheels 54 to 58 and the drive wheels 46 to 50 form pairs of wheels that have 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 on. The input shaft 60 is integral with the countershaft 52 educated. In an alternative embodiment, the input shaft 60 separately from the countershaft 52 be formed and a gear with the countershaft 52 be rotatably connected.

At the input shaft 60 is a gear 62 stored. At the output shaft 35 , which are both the output shaft of the second sub-transmission 44 as well as the output shaft of the gear unit 10 is a gear is 64 stored. The gears 62 and 64 form a constant gear set and connect the input shaft 60 with the output shaft 34 rotation. In one embodiment of the transmission unit 10 has the second partial transmission 44 a plurality of pairs of wheels having different translations. In this case, preferably, the gears that are on the input shaft 60 are stored, designed as idler gears, so that by selectively connecting the gears to the input shaft 60 different gear ratios of the second partial transmission 44 can be realized. In a particular embodiment, the first partial transmission can be used 42 be formed by a Konstantenradsatz.

In the 3 illustrated gear unit 10 has five different gear ratios, through the wheel pairs of the first sub-transmission 42 are feasible. Because the electric drive 20 with the drive shaft 32 rotatably connected, drives the electric drive 20 on the same drive shaft 32 the gear unit 10 on, like the cyclist on the cranks 16 . 16 , Because of the electric drive 20 in front of the gear unit 10 with the drive shaft 32 connected, the electric drive 20 be operated in a narrow speed range regardless of the driving speed with a speed of about 70-100 U / min. The electric drive 20 Thus, it can 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 parallel to the transmission shafts in this embodiment 32 . 34 . 52 . 60 arranged. Alternatively to the parallel offset arrangement of the electric drive 20 can the electric drive 20 also coaxial with the drive shaft 32 be arranged, in particular between the gears 46 to 50 , where the drive shaft 32 in this embodiment, the motor shaft 22 forms and thus the rotor of the electric drive 20 ,

In a further embodiment, the gear 24 directly with the gear 38 comb. Alternatively, the intermediate 40 Also be designed as a traction means or as a chain. To a desired center distance between the motor axis 22 and to achieve the gear shaft, a pair of wheels from the gear 24 and the idler 40 be used with a large pitch circle diameter.

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

At the drive shaft 32 are the drive wheels 45 to 51 stored and at the countershaft 52 are the driven wheels 53 to 59 stored. The drive gears 45 to 51 make up with the driven wheels 53 to 59 Wheel pairs that have different translations. The driven wheels 53 to 59 are designed as loose wheels and by means of switching means 61 with the countershaft 52 rotatably connected. the countershaft 52 is designed 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 the loose wheels 53 to 59 are operable to the loose wheels 53 to 59 with the countershaft 52 selectively rotatably connect. The camshaft 66 is about a speed superposition gearbox 68 with the countershaft 52 connected. The speed superposition gearbox 68 is coaxial with the countershaft 52 arranged. The speed superposition gear is through a first planetary gear 70 and a second planetary gear 72 educated. The first planetary gear 70 has a pull disk 74 on that with a ring gear of the planetary gear 70 connected is. The speed superposition gearbox 68 is designed to camshaft 66 synchronous with the countershaft 52 to rotate and a rotation of the pulley 74 as a relative movement of the camshaft 66 to the countershaft 52 on the camshaft 66 transferred to. This allows the loose wheels 53 to 59 by the relative movement of the camshaft 66 to the countershaft 52 with the countershaft 52 be connected, whereby selectively different gears or gear ratios can be realized. The loose wheels 53 to 59 are by means of switchable freewheels 61 in a drive direction with the countershaft 52 rotatably connected.

The gear 24 is about the idler 40 with the driven wheel 59 rotatably connected. This allows the rotation of the electric drive 20 on the driven wheel 59 be transmitted. Unless the driven wheel 59 not rotatably with the countershaft 52 connected, drives the driven wheel 59 the drive wheel 51 the drive shaft 32 so that a moment from the electric drive 20 on the drive shaft 32 is transmitted. This is the electric drive with the drive shaft 32 connected and the transmission unit 10 upstream. An electric traction can thus on the drive shaft 32 be transmitted.

It is understood that the gear 24 also directly with the driven wheel 59 can be engaged. It is understood that the electric drive 20 coaxial with the drive shaft 32 can be arranged. The drive shaft 32 can with the motor shaft 22 be integrally connected and the rotor of the electric drive 20 form. The electric drive 20 can also be between the drive wheels 45 to 51 be arranged. Advantage of in 4 illustrated embodiment is that the driven wheel 59 and the drive wheel 51 serve both to initiate the electric traction and as a pair of wheels of the first sub-transmission. Furthermore, superimpose the moments of the electric drive 20 and the muscle drive through the non-rotatable connection of the drive shaft 32 with the motor shaft 22 ,

The switchable freewheels 61 preferably have pawls, which in internal gears of the idler gears 53 - 59 grab these to prevent rotation with the countershaft 52 connect to. The internal camshaft 66 moves the pawls inward 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 ratchet is actuated, ie moved inwards to the higher gear completely insert. 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 the gear unit 10 upstream. It is referred to the 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 on that form pairs of wheels with different translations. The driven wheels 53 to 58 are designed as loose wheels and by means of the switching means 61 with the countershaft 52 connectable. The switching means 61 are by means of in the countershaft 52 arranged camshaft 66 selectively actuated. The camshaft 66 is with the speed superposition gearbox 68 connected to synchronously with the countershaft 52 to rotate and to switch from one gear to another relative to the countershaft 52 to be rotated.

The second partial transmission 44 has the input shaft 60 on, on the drive wheels 76 . 78 are stored. The drive wheels 76 . 78 combing with driven wheels 80 . 82 at the output shaft 34 are stored. 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 meshing drive wheels 76 . 78 and powered wheels 80 . 82 form pairs of wheels, which have different translations. The switching means 79 that drive the wheels 76 . 78 with the input shaft 60 connect, are selectively through one in the input shaft 60 rotatably mounted camshaft 84 actuated. By selectively connecting the drive wheels 76 . 78 with the input shaft 60 be different gear ratios of the second sub-transmission 44 realized. Because of that, the first partial transmission 42 and the second partial transmission 44 are connected in series, the gear stages of the two partial transmissions multiply 42 . 44 to a total number of gears of the gear unit 10 , In this case, twelve gear steps are realized.

The camshaft 84 rotates like the camshaft 66 synchronous to the input shaft 60 to maintain a set switching state and becomes relative to the input shaft 60 rotates to the switching state of the second partial transmission 44 switch. The camshaft 84 is about a driver 86 with the camshaft 66 connected. The driver 86 transmits a 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 in the following seventh gear.

The driver 86 In this case, the camshaft rotates 84 so that from the first gear of the second gearbox 44 is switched to second gear. At the same time by rotation of the camshaft 66 the first partial transmission 42 switched from sixth gear to first gear. This allows both partial transmissions 42 . 44 by actuating the pull pulley 74 of the speed superposition gear 68 turn.

The gear 24 of the electric drive 20 is about the idler 40 rotatably with the drive wheel 45 connected. This allows an electric traction on the drive shaft 32 in the gear unit 10 initiate. The advantage here is that the drive wheel 45 both part of a pair of wheels of the first sub-transmission 42 is as well as to initiate the electrical traction of the electric drive 20 serves.

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

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

In 6 is the drive unit 30 shown in which the electrical traction of the electric drive 20 over the output shaft 34 in the gear unit 10 is initiated. The gear unit 10 in 6 is identical to the one in 5 illustrated gear unit 10 , The same elements are designated by the same reference numerals, with only the differences being shown here.

The gear 24 is about the idler 40 non-rotatable with the driven wheel 78 connected. This is about the intermediate 40 and the pair of wheels through the drive wheel 78 and the driven wheel 82 is formed, a rotationally fixed connection between the electric drive 20 and the output shaft 34 educated. The drive wheel 78 is via a switchable freewheel 79 with the input shaft 60 connectable, so that the drive wheel 78 on the input shaft 60 slides, provided the rotation of the input shaft 60 larger than that of the drive wheel 78 ,

Electric traction via the output shaft 34 initiate, is advantageous because the transmission unit 10 only the muscle power of the driver must be reduced, whereby the dimensioning of the transmission in terms of durability and weight can be reduced. Furthermore, a recuperation is easily possible because the electric drive 20 with the output shaft 34 is connected and the rotation of the output shaft 34 not translated by the gear unit. However, the precondition for recuperation operation is that the chainring 36 rotatably with the output shaft 34 connected is. 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 gear unit 10 improved in this case, since the engine power in the power flow after the switchable freewheels 61 . 79 is initiated and thus can be switched without power reduction of the engine.

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

In 7 is another embodiment of the drive unit 30 shown. The gear unit 10 essentially corresponds to the gear unit 10 , in the 6 is shown. The same elements are designated by the same reference numerals, with only the differences are explained.

The intermediate wheel 40 combs with a loose wheel 88 that by means of a warehouse 90 at the input shaft 60 is stored. The idler wheel 88 is about a clutch 92 with the drive wheel 78 connectable. The coupling 92 can be designed as a one-way clutch or as a switchable clutch, the loose wheel in one or both directions 88 with the drive wheel 78 rotatably connects. Thereby, as in the embodiment according to 6 the traction of the electric drive 20 over the drive wheel 78 and the driven wheel 82 on the output shaft 34 be transmitted. Advantage of this embodiment is that the intermediate 40 and the gear 24 from the gear unit 18 can be decoupled, so that these gears do not rotate permanently in pure muscle operation. In this embodiment may further on a separate coupling on or in the electric drive 20 be waived. The coupling 92 can, for example, on the camshaft 84 in the wave 60 be operated.

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 coupling 92 can generally be designed as a switchable clutch or switchable freewheel, in particular as a sprag freewheel, as an axial overrunning clutch with an end-face toothing, as a pawl freewheel or as a switchable friction clutch.

In 8th is the drive unit 30 shown in which the electric traction on the countershaft 52 or the input shaft 60 of the second partial transmission 44 is initiated. The gear unit 10 corresponds essentially to the gear unit 5 and 6 , The same 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 is a freewheel 94 stored. The freewheel 94 blocked in a drive direction of the electric drive 20 with the input shaft 60 and slides on the input shaft 60 in an opposite direction of rotation. This will cause the electrical traction of the electric drive 20 from the gear 24 over the intermediate wheel 40 and the freewheel 94 on the countershaft 52 or the input shaft 60 transfer. Unless the input shaft 60 rotates faster than the freewheel 94 , the freewheel slides 94 on the input shaft 60 or slides the input shaft 60 under the freewheel 94 by. The electric drive 20 is thus the freewheeling 61 of the first partial transmission 42 downstream and the freewheeling 79 of the second partial transmission 44 upstream. This advantageously the driving force of the electric drive 20 not through the first partial transmission 42 transmitted, but only by the second partial transmission 44 , whereby the first partial transmission 42 can be dimensioned correspondingly smaller. Because of the electric drive 20 the second partial transmission 44 upstream, the speed range of the electric drive 20 be correspondingly narrower dimensioned, whereby the design of the electric drive 20 can be smaller and lighter dimensions. In general, it is preferred when the traction of the electric drive 20 on the countershaft 52 or the input shaft 60 in the axial direction as close as possible to the second partial transmission 44 is initiated. It is particularly preferred when the traction of the electric drive on the input shaft 60 at an axial end of the input shaft 60 , on one of the countershafts 52 opposite side, is initiated. This will increase the torsional load on the countershaft 52 or the input shaft 60 reduced, resulting in a longer life of the shaft.

When recuperation energy is recovered when braking the vehicle, which is to charge the battery 21 or a battery can be used to increase the range of the vehicle increase. For this purpose, a separate generator can be integrated into the system, which in the drive unit 30 is installed or arranged as an external component on the vehicle and can be switched separately comparable to a dynamo. There is basically the possibility of the electric drive 20 to use as a generator in the braking phases of the vehicle. However, this is only possible if the electric drive 20 after the freewheels of the second sub-transmission 44 is coupled, since this is a turning of the electric drive 20 during the rolling or braking phases do not allow, but change to the freewheel. Such recuperation by means of the electric drive 20 is thus possible if the motor shaft 22 with the output shaft 34 is rotatably connected or if the motor shaft 22 with the input shaft 60 or the counter-wave 52 rotatably connected and the second partial transmission 44 is designed as a constant gear. Further, it is necessary for the recuperation operation that the output shaft 34 is driven in 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 mode.

As described above, is between the electric drive 20 and the gear unit 10 preferably the clutch 28 arranged so that the vehicle can be driven by pure muscle power without the engine rotates. In case of recuperation, the clutch must 28 the torque, so the braking torque, transmitted in the opposite direction of rotation, so that a simple one-way clutch for the recuperation is inappropriate. In a variant of the drive unit 30 is therefore the clutch 28 formed 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.

At the freewheel 94 according to 8th Accordingly, a recuperation without further action is not possible.

In 9 is an embodiment of the drive unit 30 shown schematically with switchable freewheel. The gear unit 10 is essentially identical to the gear unit 10 out 8th , The same elements are designated by the same reference numerals, with only the differences being explained here.

At the input shaft 60 is in place of the freewheel 94 a ratchet wheel 96 stored. The ratchet wheel 96 is designed as a loose wheel and by means of pawls 99 with the input shaft 60 rotatably connected. The pawls 99 are designed such that they the ratchet wheel 96 in one direction with the input shaft 60 rotatably connect and switch in an opposite direction in the freewheel. The ratchet wheel 96 has the pawls 99 on, in the drive direction the ratchet wheel 96 with the input shaft 60 rotatably connect, and more pawls 101 that the ratchet wheel 96 in the opposite direction of rotation with the input shaft 60 rotatably connect. The pawls 99 . 101 are through a camshaft 98 selectively actuated. The camshaft 98 is with a speed superposition gearbox 100 connected, which is adapted to the camshaft 98 synchronous to the input shaft 60 to rotate and to an operation of the speed superposition gear 100 relative to the input shaft 60 to rotate. Due to the relative rotation of the camshaft 98 become the pawls 99 . 101 selectively actuated so that the corresponding reverse direction of the ratchet wheel 96 can be changed. As a result, either the pawls arranged in the first direction or in the opposite direction can be used 99 . 101 be switched. Thus, between a drive operation, in the traction of the electric drive 20 in the gear unit 10 is initiated, are switched to a recuperation, in the overrun torque on the electric drive 20 transferred and converted accordingly into electrical energy. Alternatively, only the pawl 101 for recuperation through the camshaft 98 operated, the pawl 99 always swung out and in drive mode, the input shaft 60 with the ratchet wheel 96 rotatably connects and switches in recuperation mode in the freewheel.

The speed superposition gearbox 100 is identical to the speed superposition gearbox 68 , The speed superposition gearbox 100 has a first planetary gear 102 on, its sun gear with the camshaft 98 is connected and the ring gear with a pull pulley 104 connected is. The planet carrier of the planetary gear 102 is with a planet carrier of a second planetary gear 106 connected, whose sun gear with the input shaft 60 is connected and the ring gear is mounted fixed to the housing.

By rotation of the pulley 104 becomes the camshaft 98 relative to the input shaft 60 rotated so that the pawls 99 . 101 of the switching wheel 96 be switched. As a result, the reverse direction of the ratchet wheel 96 reversible, which can be switched by the electric drive in the recuperation. The pull disk 104 is preferably operated by means of a Bowden cable. The pull disk 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 to the recuperation during each braking process.

The speed superposition gearbox 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 connected is. 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 gearbox 100 can also be replaced by a corresponding actuator, both with the input shaft 60 as well as with the camshaft 98 connected is.

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

Upon initiation of electric traction via the countershaft 52 or the input shaft 60 of the second partial transmission 44 is used to switch the second sub-transmission 44 the electric drive interrupted.

In 10 is an alternative embodiment of the drive unit 30 out 8th and 9 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 essentially identical to the gear unit 8th and 9 , The same elements are designated by the same reference numerals, with only the differences being explained here.

Instead of the freewheel 94 is at the drive unit 30 in 10 a crown wheel 108 with the input shaft 60 connected. The crown wheel 108 is with the idler 40 rotatably connected, which rotates about an axis orthogonal to the transmission shafts. The intermediate wheel 40 is with the gear 24 of the electric drive 20 connected, the motor shaft 22 oriented orthogonally to the transmission shafts. Due to the orthogonal arrangement of the motor shaft 22 can the electric drive 20 in a tube of the frame 12 be installed, causing the electric drive 20 saves space in the frame 12 can be installed. The crown wheel 108 can rotate with the input shaft 60 be connected.

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

In 11 is another embodiment of the drive unit 30 shown schematically, in which the motor shaft 22 oriented orthogonally to the transmission shafts and the electric traction across the output shaft 34 in the gear unit 10 is initiated. The gear unit 10 is essentially identical to the one in 6 illustrated gear unit 30 , The same elements are designated by the same reference numerals, with only the differences being explained here.

The drive wheel 76 of the second partial transmission 44 is via a bevel gear pairing 110 with the motor shaft 22 rotatably connected. The bevel gear pairing 110 has a bevel gear 112 on, the rotation with the motor shaft 22 is connected, and a bevel gear section 114 , which rotates with the drive wheel 76 connected is. By the bevel gear pairing 110 is the drive wheel 76 with the motor shaft 22 connected, which is arranged orthogonal to the transmission shafts. As a result, as in the embodiment 10 the electric drive 20 in a tube of the frame 12 , z. B. in the down tube or in the seat tube, are installed.

In addition to the compact design of the bicycle is the electric drive 20 Protected against impact and weather conditions when housed in a frame tube and the appearance of the bicycle becomes more compact and sportier, as the electric drive 20 is not visible from the outside.

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

The drive wheel 78 has an internal toothing 116 on, in which the pawls 99 . 101 can engage the drive wheel 78 with the input shaft 60 rotatably connected in the corresponding direction. Here is the pawl 99 aligned so that they are the drive wheel 78 in the drive direction of the electric machine 20 rotatably with the input shaft 60 combines. The pawl 101 is oriented so that the drive wheel in the opposite direction, the Rekuperationsrichtung rotatably connected to the input shaft 60 combines. The pawl 101 is at the input shaft 60 pivotally mounted and has an inner portion 118 and an outer section 120 on. The inner section 118 is from the camshaft 98 actuated such that in the internal toothing 116 engaging outer gate 120 is pivoted inward to the pawl 101 out of engagement of the internal teeth 116 bring to. To the pawl 101 with the internal toothing 116 to engage has the camshaft 98 a recess 122 on, in which the inner section 118 the resiliently biased pawl 101 swings inwards. As a result, the outer pans section 120 to the outside and engages in the internal teeth 116 , causing the input shaft 60 with the drive wheel 78 is connected rotatably in Rekuperationsrichtung. The pawl 99 for the drive direction is in this embodiment by the camshaft 98 not actuated and runs in recuperation with the freewheel and connects the drive wheel 78 with the input shaft 60 rotationally fixed in drive direction. Alternatively, the pawls 99 . 101 alternately from the camshaft 98 be operated so that either the pawl 99 or the pawl 101 swung out.

By the in 12 illustrated pawls 99 . 101 is by rotation of the camshaft 98 switching to the recuperation possible.

QUOTES INCLUDE IN THE DESCRIPTION

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

Cited patent literature

• DE 102008064514 A1 [0004]

Claims (20)

Drive unit ( 30 ) for a muscle-powered vehicle, with a first shaft ( 52 . 60 ), at which a plurality of gears ( 53 - 59 . 62 . 76 . 78 ) and a second shaft ( 32 . 34 ), on which a corresponding plurality of gears ( 45 - 51 . 64 . 80 . 82 ) mounted with the gears ( 53 - 59 . 62 . 76 . 78 ) of the first wave ( 52 . 60 ), characterized in that one of the transmission shafts ( 32 . 34 . 52 . 60 ) with a motor shaft ( 22 ) an electric machine ( 20 ) is connected or connectable to a torque in the transmission ( 10 ) on or off the transmission ( 10 ) decouple. Drive unit according to claim 1, characterized in that the drive unit ( 30 ) a drive shaft ( 32 ) and an output shaft ( 34 ), wherein the first wave ( 52 . 60 ) as a countershaft ( 52 . 60 ) and the second wave ( 32 . 34 ) the output shaft ( 34 ) or the input shaft ( 32 ), whereas those at the countershaft ( 52 . 60 ) mounted gears ( 53 - 59 . 62 . 76 . 78 ) each with a gear ( 45 - 51 . 64 . 80 . 82 ) on the drive shaft ( 32 ) or the output shaft ( 34 ) is stored. Drive unit according to claim 2, characterized in that the gear shaft, the drive shaft ( 32 ). Drive unit according to claim 2, characterized in that the transmission shaft, the countershaft ( 52 . 60 ). Drive unit according to claim 2, characterized in that the transmission shaft, the output shaft ( 34 ). Drive unit according to one of claims 2 to 5, characterized in that on the drive shaft ( 32 ) a plurality of gears ( 45 - 51 ) mounted with gears ( 53 - 59 ) of the countershaft ( 52 . 60 ) a partial transmission ( 42 ), the gears ( 53 - 59 ) of the countershaft ( 52 . 60 ) are designed as loose wheels, by means of switching means ( 61 ) with the countershaft ( 52 . 60 ) are rotatably connected. Drive unit according to one of claims 2 to 6, characterized in that on the output shaft ( 34 ) a plurality of gears ( 64 . 80 . 82 ) mounted with gears ( 62 . 76 . 78 ) of the countershaft ( 52 . 60 ) a partial transmission ( 44 ), the gears ( 62 . 76 . 78 ) of the countershaft ( 52 . 60 ) are designed as idler gears and by means of switching means ( 79 ) with the countershaft ( 60 ) are rotatably connected. Drive unit according to claim 6 or 7, characterized in that the switching means ( 61 . 79 ) switchable freewheels ( 61 ), which by means of a formed in the form of a hollow shaft countershaft ( 52 . 60 ) mounted camshaft ( 66 . 84 ) are operable. Drive unit according to one of claims 1 to 8, characterized in that the electrical machine ( 20 ) via a reduction gear ( 26 ) with the respective transmission shaft ( 32 . 34 . 52 . 60 ) is connectable. Drive unit according to one of claims 1 to 9, characterized in that the electric machine ( 20 ) by means of a coupling ( 28 ), in particular a clutch or a switchable freewheel with the respective transmission shaft ( 32 . 34 . 52 . 60 ) is connectable. 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 . 82 ) of the transmission shafts ( 32 . 34 . 52 . 60 ) is rotatably connected. Drive unit according to one of claims 1 to 11, characterized in that the motor shaft ( 22 ) by means of a switching wheel ( 94 . 96 ), which is connected to one of the transmission shafts ( 34 . 52 . 60 ) is mounted, at least in one direction of rotation rotatably with the transmission shaft ( 34 . 52 . 60 ) is connectable. 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. Drive unit according to one of the claims 12 or 13, characterized in that the ratchet 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. 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 operable. 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. Drive unit according to one of claims 1 to 16, characterized in that the motor shaft ( 22 ) of the electric machine ( 20 ) parallel to the gear shafts ( 32 . 34 . 52 . 60 ) is arranged. 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. Drive unit according to one of claims 1 to 17, characterized in that the motor shaft ( 22 ) of the electric machine ( 20 ) in one piece with one of the transmission shafts ( 32 . 34 . 52 . 60 ) is trained. Bicycle ( 12 ) with a drive unit ( 30 ) according to one of claims 1 to 19.

Images