BACKGROUND OF THE INVENTION AND PRIOR ART The present invention pertains to a transmission according to the preamble of claim 1 . The invention also pertains to a vehicle comprising such a transmission according to claim 12.

Transmissions in vehicles are used to transmit power from a driving device to a driven device via an input shaft in the transmission and an output shaft in the transmission. The driving device may e.g. be an internal combustion engine or an electric motor and the driven device may be the vehicle's driving wheels, an oil pump, a fuel pump or similar. When the driving device changes rotational direction, the rotational direction of the transmission's input shaft also changes. Usually, this also entails that the transmission's output shaft changes rotational direction. Depending on the construction of the driven device, this may be more or less suitable. In cases where the driven device may only be operated in one rotational direction, variations in the rotational direction of the input shaft cause problems.

In order to lubricate and cool the transmission and to prevent corrosion, a transmission oil is supplied. Where the transmission is a gearbox in a vehicle, the oil is supplied via an oil pump, which may be operated by the internal com- bustion engine via a layshaft of the gearbox. Where the combustion engine does not operate the layshaft, this leads to the oil pump standing still and no oil is supplied to the gearbox transmission. In certain operating modes where the layshaft is at a standstill, e.g. in generator operation with hybrid vehicles at a standstill, it would, however, still be desirable to supply oil. One way of resolv- ing this problem is to operate the oil pump with the electric motor that operates the hybrid vehicle. The electric motor changes rotational direction, however, when it acts as a generator and thus rotates alternating between a clockwise

RECORD COPY TRANSLATION and counterclockwise direction. In cases where the oil pump may only be operated in one rotational direction, it is therefore desirable to achieve a transmission which generates a specific direction of the output shaft, depending on the rotational direction of the input shaft.

There are different solutions in relation to actuators for the oil pump of a gearbox where the oil pump is operated by an electric motor. Document DE

102007043737 A1 describes a driving device in a hybrid vehicle comprising a transmission between an electric motor and a pump. The transmission com- prises a planetary gear, wherein one part of the planetary gear is connected with the electric motor, one part is connected with a brake and one part is connected with the pump. A freewheel is also arranged between the electric motor and the pump so that, where the pump rotates slower than the electric motor, the pump is operated directly by the electric motor instead of via the planetary gear.

Document JP2004096970 shows a device to operate a hydraulic pump. The device comprises a transmission between a driving shaft and the pump, wherein the transmission comprises freewheels to be able to shift between different driving units in order to operate the pump optimally both when it is in operation and when it is at a standstill.

Further, document DE102006037577 A1 shows a driving device for an aggregate comprising a transmission with freewheels in order to be able to operate the aggregate with an electric motor when the combustion engine is at a standstill. SUMMARY OF THE INVENTION

Despite prior art solutions in this area, there is a need to further develop a transmission which transmits power in an optimal manner from a driving device to a driven device.

The objective of the present invention is to achieve a transmission which generates a specific rotational direction in its output shaft, regardless of the rotational direction of its input shaft.

The objective of the present invention is also to achieve a transmission which entails a flexible operation of a driven device.

Another objective of the invention is to achieve a transmission which enables optimal use of a driven device.

These objectives are achieved with a transmission of the type specified at the beginning and which is characterised by the features specified in the characterising portion of claim 1 .

By arranging a first coupling device in connection with two components comprised in the planetary gear and a second coupling device in connection with the planetary wheel carrier and a section which is static in relation to the planetary wheel carrier, the first coupling device allows for connection of both com- ponents at a first rotational direction of the input shaft and the second coupling device allows for locking of the planetary wheel carrier to the static section and thus prevents rotation of the planetary wheel carrier at a second rotational direction of the input shaft. The first rotational direction and the second rotational direction are opposite to each other. When the first coupling device connects the two components, the second coupling device allows the planetary wheel carrier to rotate, and when the second coupling device locks the planetary wheel carrier, the first coupling device allows the two components to rotate separately. By connecting two components comprised in the planetary gear, the positions of all of the components comprised are locked in relation to each other and all the components rotate in the same rotational direction. By arranging the first and the second coupling devices in accordance with the present invention, the output shaft of the transmission will rotate, at one of the rotational directions of the input shaft, in the same rotational direction as the input shaft, and at the input shaft's second rotational direction, the output shaft will rotate in an opposite rotational direction. The output shaft will thus always rotate with the same rotational direction. Thus, a transmission is achieved that generates a specific rotational direction in its output shaft, regardless of the rotational direction of its input shaft. Thus the present invention is particularly suitable to operate a driven device which may only be operated in one rotational direction. The transmission according to the present invention may thus be operated by a driving device that changes rotational direction without im- pacting the rotational direction of the transmission's output shaft. Thus, a transmission is achieved which entails a flexible operation of a driven device and which facilitates optimal use of the driven device.

A planetary gear means a transmission consisting of a number of cog ele- ments that are in constant contact and that rotate around their respective shafts. A planetary gear comprises a ring gear, a sun wheel, one or several planetary wheels (satellite wheels) and a planetary wheel carrier. The planetary wheels are arranged in engagement with the sun wheel, so that when the planetary wheels rotate around their own shafts, they also circulate around the centrally arranged sun wheel. The planetary wheels are also arranged on a moveable planetary wheel carrier, which may rotate in relation to the sun wheel around a shaft which is concentric with the shaft of the sun wheel. The ring gear is arranged so that it surrounds the sun wheel and the planetary wheels and rotates around a shaft which is concentric with the shaft of the sun wheel. The planetary wheels are in engagement with the ring gear's inner cogs. The different components comprised may be locked individually to achieve different gearings. The first coupling device is preferably arranged in connection with the ring gear and the planetary wheel carrier. When the transmission's input shaft rotates with a first rotational direction, the first coupling device thus locks the ring gear and the planetary wheel carrier together, which as a result rotate with the same rotational direction. When the input shaft changes rotational direction to the second rotational direction, the first coupling device opens up and the second coupling device locks the planetary wheel carrier to the static section. Alternatively, the first coupling device is arranged in connection with the sun wheel and the planetary wheel carrier. When the transmission's input shaft rotates with a first rotational direction, the first coupling device thus locks the sun wheel and the planetary wheel carrier together, which as a result rotate in the same rotational direction. When the input shaft changes rotational direction to the second rotational direction, the first coupling device opens up and the second coupling device locks the planetary wheel carrier to the static section.

Alternatively, the first coupling device is arranged in connection with the ring gear and the sun wheel. When the transmission's input shaft rotates with a first rotational direction, the first coupling device thus locks the ring gear and the sun wheel together, which as a result rotate in the same rotational direction. When the input shaft changes rotational direction to the second rotational direction, the first coupling device opens up and the second coupling device locks the planetary wheel carrier to the static section.

The first coupling device preferably consists of a first freewheel and the second coupling device preferably consists of a second freewheel. A freewheel is a mechanical coupling which is driving in one rotational direction but disconnected in the opposite direction. By arranging freewheels between two compo- nents, both components are connected in one rotational direction, and in the opposite rotational direction the freewheel is disconnected and both components are independent of each other. Alternatively, the first and the second coupling devices consist of friction couplings or form-bound couplings, which are controlled by a control device. The control device is suitably arranged in connection with the driving device and controls the respective couplings depending on the rotational direction of the driving device. The control device thus controls the first friction coupling/form- bound coupling, so that it is closed and connects the two components comprised in the planetary gear, at a first rotational direction of the input shaft. The control device also controls the second friction coupling/form-bound coupling, so that it is closed and accordingly locks the planetary wheel carrier to the static section, at a second rotational direction of the input shaft. The first and the second coupling devices may, alternatively, consist of claw couplings, cone couplings, disc couplings such as plate couplings, or similar. The input shaft of the transmission is connected to the ring gear and the output shaft is connected to the sun wheel. By arranging the output shaft in connection with the sun wheel, a compact transmission is achieved which may be arranged at the driven device. When the input shaft rotates in the first rotational direction, the first coupling device connects the two components comprised in the planetary gear, which leads to all of the components of the planetary gear rotating in the same rotational direction. When the input shaft changes rotational direction and rotates with the second rotational direction, the first coupling device is disconnected and allows for individual rotation of the two components while the second coupling device locks the planetary wheel carrier. When the planetary wheel carrier is static, the planetary wheels rotate only around their own shafts and not around the sun wheel. Since the planetary wheels are in engagement with both the ring gear and the sun wheel and only rotate around their own shaft, the ring gear and the planetary wheels will thus rotate in the same rotational direction while the planetary wheels and the sun wheel will rotate in opposite rotational directions. Accordingly, the ring gear and the sun wheel will always rotate in different rotational directions when the planetary wheel carrier is locked. Where the input shaft is directly connected with the ring gear, the first rotational direction of the input shaft entails that the ring gear rotates in the same first rotational direction, and the first coupling device's connection of two com- ponents also entails that the sun wheel rotates in the same first rotational direction. Accordingly, the output shaft rotates in the same rotational direction as the input shaft. When the input shaft rotates in the second rotational direction, the ring gear rotates in the same rotational direction while the sun wheel rotates in an opposite rotational direction. Thus, the sun wheel and therefore the output shaft still rotate in the first rotational direction. Accordingly, the output shaft will always rotate in the same rotational direction, regardless of the rotational direction of the input shaft.

Alternatively, the input shaft is connected to the ring gear via a cogwheel ar- ranged at the input shaft, whose cogwheel is arranged in connection with outer cogs arranged on the ring gear. The first rotational direction of the input shaft and the cog wheel entails that the ring gear rotates in an opposite rotational direction, and the first coupling device's connection of two components entails that the sun wheel also rotates in the same first rotational direction. Accord- ingly, the output shaft rotates in a rotational direction opposite to the first rotational direction of the input shaft. When the input shaft rotates with the second rotational direction the ring gear again rotates in an opposite rotational direction. The sun wheel, and therefore the output shaft, on the other hand rotate in a rotational direction which is opposite to the rotational direction of the ring gear and therefore in the same rotational direction as the input shaft. Accordingly, the output shaft will always rotate in the same rotational direction, regardless of the rotational direction of the input shaft.

It is also possible that the input shaft of the transmission is connected to the sun wheel and the output shaft is connected to the ring gear. The output shaft may then be directly connected to the ring gear or connected via a cogwheel arranged at the output shaft, which is in engagement with the outer cogs of the ring gear. This solution may be preferable in other types of installations than those exemplified in this application.

The driving device, which is connected to the input shaft of the transmission, is preferably an electric motor. By controlling the speed of the electric motor, the driven device may, via the transmission, be operated in a flexible and optimal manner. Thus, a transmission is achieved which entails a flexible operation of a driven device and which facilitates optimal use of the driven device. The driven device, which is connected to the output shaft of the transmission, is preferably an oil pump. The oil pump is suitably of the type that it may only be operated in one rotational direction. The transmission according to the present invention entails that the output shaft always rotates in one and the same rotational direction. Accordingly, the operation of the oil pump may be ensured regardless of whether the driving device, and therefore the input shaft, changes rotational direction.

Other advantages of the invention are set out in the detailed description below. BRIEF DESCRIPTION OF THE DRAWINGS

Below is a description of, as examples, preferred embodiments of the invention with reference to the enclosed drawings, in which: shows schematically a transmission according to one embodiment of the present invention,

shows the transmission in Fig. 1 at a first rotational direction of an input shaft,

shows the transmission in Fig. 1 at a second rotational direction of the input shaft,

shows schematically a transmission according to one embodiment of the present invention, shows schematically a transmission according to one embodiment of the present invention,

shows schematically a transmission according to one alternative embodiment,

shows schematically a transmission according to one alternative embodiment,

shows schematically a transmission according to one alternative embodiment,

shows schematically a transmission according to one embodiment of the present invention, and

shows a schematic side view of a vehicle comprising a transmission according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Fig. 1 shows a schematic side view of a transmission 1 according to one embodiment of the present invention. The transmission 1 comprises a planetary gear 2 with a ring gear 4, a sun wheel 6, three planetary wheels 8 (only two displayed) and a planetary wheel carrier 10. Further, the transmission 1 com- prises a cogwheel 12 arranged at the input shaft 14 of the transmission 1 . The cog wheel 12 is arranged in engagement with external cogs arranged on the ring gear 4 (not displayed) and operates the ring gear 4. Accordingly, the input shaft 14 is connected to the ring gear 4. The output shaft 16 of the transmission 1 is arranged in connection with the sun wheel 6. Further, the input shaft 14 is connected to a driving device E, which consists of an electric motor. The output shaft 16 is connected to and operates a driven device P, which consists of an oil pump. A first coupling device 18 in the form of a first freewheel is arranged between and in connection with the ring gear 4 and the planetary wheel carrier 10. The first freewheel 18 locks the planetary wheel carrier 10 to the ring gear 4 at a first rotational direction of the input shaft 14, so that the planetary wheel carrier 10 and the ring gear 4 rotate together in the same rotational direction. At a second rotational direction of the input shaft 14 the first freewheel 18 allows for separate rotations of the planetary wheel carrier 10 and the ring gear 4. The first rotational direction and the second rotational direction are opposite to each other. Further, a second coupling device 20 in the form of a second freewheel is arranged between and in connection with the planetary wheel carrier 10 and a static section 21 in relation to the planetary wheel carrier 10, e.g. a transmission house. The second freewheel 20 allows for rotation of the planetary wheel carrier 10 at a first rotational direction of the input shaft 14 and locks the planetary wheel carrier 10 to the static section 21 and prevents rotation at the second rotational direction of the input shaft 14. The first freewheel 18 and the second freewheel 20 are thus arranged in opposite directions to (mirroring) each other, so that when the first freewheel 18 is locked, and thus connects the planetary wheel carrier 10 and the ring gear 4, the second freewheel 20 is disconnected and accordingly allows for rotation of the planetary wheel carrier 10 and vice versa. The function of the transmis- sion 1 is described in further detail in Figs. 2a-2b below.

Fig. 2a shows the transmission 1 according to Fig. 1 in a view seen from the front, where the cogwheel 12 of the input shaft 14 rotates in a first rotational direction. Rotational directions are illustrated with arrows in the figure, and in order to clarify the transmission's 1 function the first rotational direction is described as clockwise and the second rotational direction is described as counterclockwise. The cogwheel 12 is arranged in engagement with the outer cogs of the ring gear 4 (not displayed), so that where the cog wheel 12 rotates in a clockwise direction, the ring gear 4 rotates in a counterclockwise direction. The first freewheel 18 is arranged so that when the input shaft 14 and therefore the cogwheel 12 rotate in the first rotational direction, the planetary wheel carrier 10 is locked to the ring gear 4. The second freewheel 20 is simultaneously arranged so that at the input shaft's 14 first rotational direction it allows for rotation of the planetary wheel carrier 10. The first freewheel 18 is here illustrated with dashes, symbolising the locking of the planetary wheel carrier 10 and the ring gear 4. The locking entails that the planetary wheel carrier 10 rotates in the same rotational direction as the ring gear 4 (counterclockwise), which in turn means that the planetary wheels 8 do not rotate around their own shaft and are not able to circulate in relation to the ring gear 4 or the sun wheel 6, but follow the rotation of the ring gear 4. The engagement of the planetary wheels 8 with the sun wheel 6 accordingly entails that the ring gear 4, the planetary wheel carrier 10, the planetary wheels 8 and the sun wheel 6 rotate in the same rotational direction, namely counterclockwise. Where the output shaft 16 is connected to the sun wheel 6, a clockwise rotation of the input shaft 14 therefore entails that the output shaft 16 rotates in a counterclockwise direction.

Fig. 2b shows the transmission 1 according to Fig. 2a in a view seen from the front, where the cogwheel 12 of the input shaft 14 rotates in a second rotational direction, namely counterclockwise. At the second rotational direction the first freewheel 18 is disconnected and the planetary wheel carrier 10 and the ring gear 4 are no longer connected. The second freewheel 20 entails, however, that the planetary wheel carrier 10 is locked to the static section 21 , so that a rotation of the planetary wheel carrier 10 is prevented. The locking of the planetary wheel carrier 10 to the static section 21 is illustrated with dashes between the planetary wheel carrier 10 and earth. The placement and function of both freewheels 18, 20 thus entail that when the cogwheel 12 and the input shaft 14 rotate counterclockwise, the ring gear 4 rotates clockwise while the planetary wheel carrier 10 is stationary. This entails that the planetary wheels 8 rotate clockwise around their own shaft, which in turn entails that the sun wheel 6 rotates counterclockwise. Thus, a counterclockwise rotation of the in- put shaft 14 entails that the output shaft 16 rotates counterclockwise. By arranging the first freewheel 18 and the second freewheel 20 according to the present invention, a transmission 1 is achieved that generates a specified rotational direction of its output shaft 16, regardless of the rotational direction of its input shaft 14. Accordingly, the present transmission 1 facilitates operation of an oil pump P via an electric motor E, also in cases where the oil pump P may only be operates in one rotational direction. Fig. 3a shows a schematic side view of a transmission 1 according to one embodiment of the present invention. The transmission 1 according to Fig. 3a is adapted according to the transmission 1 as per Fig. 1 , with the difference that the first freewheel 18 is arranged in an alternative manner. The first freewheel 18 is here arranged between, and in connection with, the planetary wheel carrier 10 and the sun wheel 6. The first freewheel 18 is arranged so that the planetary wheel carrier 10 is locked to the sun wheel 6 at the first rotational direction of the input shaft 14 and therefore the cogwheel 12. The second freewheel 20 is arranged so that the rotation of the planetary wheel carrier 10 is allowed at the first rotational direction of the input shaft 14 and therefore the cogwheel 12. In order to clarify how the transmission 1 functions, the input shaft's 14 first rotational direction is set to be clockwise and the second rotational direction is counterclockwise. The cogwheel 12 is arranged in engagement with the ring gear 4, so that where the cog wheel 12 rotates in a clock- wise direction, the ring gear 4 rotates in a counterclockwise direction. The locking between the sun wheel 6 and the planetary wheel carrier 10 entails that the planetary wheels 8, the planetary wheel carrier 10 and the sun wheel 6 rotate in the same rotational direction as the ring gear 4. Thus, a clockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. When the input shaft 14 and the cog wheel 12 rotate in the second rotational direction, counterclockwise in this example, the second freewheel 20 locks the planetary wheel carrier 10 to the static section 21 , so that the rotation of the planetary wheel carrier 10 is prevented. The first freewheel 18 no longer entails any locking between the planetary wheel carrier 10 and the sun wheel 6. The function of both freewheels 18, 20 thus entail that when the cogwheel 12 rotates counterclockwise, the input shaft 4 rotates clockwise while the planetary wheel carrier 10 is stationary. This entails that the planetary wheels 8 also rotate clockwise around their own shaft, which in turn entails that the sun wheel 6 rotates counterclockwise. Thus, a counterclockwise rotation of the in- put shaft 14 entails that the output shaft 16 rotates counterclockwise. By arranging the first freewheel 18 and the second freewheel 20 according to the present invention, a transmission 1 is achieved which generates a specified rotational direction of its output shaft 16, regardless of the rotational direction of its input shaft 14.

Fig. 3b shows a schematic side view of a transmission 1 according to one em- bodiment of the present invention. The transmission 1 according to Fig. 3b is adapted according to the transmission 1 as per Fig. 1 , with the difference that the first freewheel 18 is arranged in an alternative manner. The first freewheel 18 is here arranged between, and in connection with, the ring gear 4 and the sun wheel 6. The first freewheel 18 is arranged so that the ring gear 4 is locked to the sun wheel 6 at the first rotational direction of the input shaft 14 and therefore the cogwheel 12. The second freewheel 20 is arranged so that the rotation of the planetary wheel carrier 10 is allowed at the first rotational direction of the input shaft 14 and therefore the cogwheel 12. In order to clarify how the transmission 1 functions, the input shaft's 14 first rotational direction is set to be clockwise and the second rotational direction is counterclockwise. The cogwheel 12 is arranged in engagement with the outer cogs of the ring gear 4, so that when the cog wheel 12 rotates in a clockwise direction, the ring gear 4 rotates in a counterclockwise direction. The locking between the ring gear 4 and the sun wheel 6 entails that the sun wheel 6, and therefore the planetary wheels 8 and the planetary wheel carrier 10 rotate in the same rotational direction as the ring gear 4. Thus, a clockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. When the input shaft 14 and the cog wheel 12 rotate in the second rotational direction, counterclockwise in this example, the second freewheel 20 locks the planetary wheel carrier 10 to the static section 21 , so that the rotation of the planetary wheel carrier 10 is prevented. The first freewheel 18 no longer entails any locking between the ring gear 4 and the sun wheel 6. The freewheels 18, 20 thus entail that when the cogwheel 12 rotates counterclockwise, the ring gear 4 rotates clockwise while the planetary wheel carrier 10 is stationary. This entails that the planetary wheels 8 also rotate clockwise around their own shaft, which in turn entails that the sun wheel 6 rotates counterclockwise. Thus, a counterclockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. By arranging the first freewheel 18 and the second freewheel 20 according to the present invention, a transmission 1 is achieved which generates a specified rotational direction of its output shaft 16, regardless of the rotational direction of its input shaft 14.

Fig. 4a shows a schematic side view of a transmission 1 according to one alternative embodiment. The transmission 1 is adapted according to the transmission 1 described in Fig. 1 , with the difference that the transmission's 1 input shaft 14 is connected to the sun wheel 6 and the transmission's 1 output shaft 16 is connected to the ring gear 4 via a cogwheel 22 arranged at the output shaft 16. Thus, the electric motor E is connected to and operates the sun wheel 6 while the oil pump P is connected to and operated by the ring gear 4. When the input shaft 14 and therefore the sun wheel 6 rotate in a first rotational direction, e.g. clockwise, the locking between the ring gear 4 and the planetary wheel carrier 10 entails that the planetary wheels 8, the planetary wheel carrier 10 and the ring gear 4 also rotate clockwise. The cogwheel 22 is arranged in engagement with the outer cogs of the ring gear 4 and thus rotates counterclockwise. Thus, a clockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. When the input shaft 14 and the sun wheel 6 rotate in the second rotational direction, counterclockwise in this example, the second freewheel 20 locks the planetary wheel carrier 10 to the static section 21 , so that the rotation of the planetary wheel carrier 10 is prevented. The first freewheel 18 no longer entails any locking between the ring gear 4 and the planetary wheel carrier 10. The placement and function of both freewheels 18, 20 thus entail that when the sun wheel 6 rotates counterclockwise, the planetary wheels 8 rotate clockwise around their own shaft while the planetary wheel carrier 10 is stationary. This entails that the ring gear 4 also rotates clockwise which in turn entails that the cogwheel 22 rotates counterclockwise. Thus, a counterclockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. Thus, a transmission 1 is achieved which generates a specific rotational direction in its output shaft 16, regardless of the rotational direction of its input shaft 14. Fig. 4b shows a schematic side view of a transmission 1 according to one alternative embodiment. The transmission 1 is adapted according to the transmission 1 described in Fig. 3a, with the difference that the transmission's 1 input shaft 14 is connected to the sun wheel 6 and the transmission's 1 output shaft 16 is connected to the ring gear 4 via a cogwheel 22 arranged at the output shaft 16. Thus, the electric motor E is connected to and operates the sun wheel 6, while the oil pump P is connected to and operated by the ring gear 4. When the input shaft 14 and therefore the sun wheel 6 rotate in a first rota- tional direction, e.g. clockwise, the locking between the planetary wheel carrier 10 and the sun wheel 6 entails that the planetary wheels 8, the planetary wheel carrier 10 and the ring gear 4 also rotate clockwise. The cogwheel 22 is arranged in engagement with the outer cogs of the ring gear 4 and thus rotates counterclockwise. Thus, a clockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. When the input shaft 14 and the sun wheel 6 rotate in the second rotational direction, counterclockwise in this example, the second freewheel 20 locks the planetary wheel carrier 10 to the static section 21 , so that the rotation of the planetary wheel carrier 10 is prevented. The first freewheel 18 no longer entails any locking between the plane- tary wheel carrier 10 and the sun wheel 6. The placement and function of both freewheels 18, 20 thus entail that when the sun wheel 6 rotates counterclockwise, the planetary wheels 8 rotate clockwise around their own shaft while the planetary wheel carrier 10 is stationary. This entails that the ring gear 4 also rotates clockwise which in turn entails that the cogwheel 22 rotates counter- clockwise. Thus, a counterclockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. Thus, a transmission 1 is achieved which generates a specific rotational direction in its output shaft 16, regardless of the rotational direction of its input shaft 14. Fig. 4c shows a schematic side view of a transmission 1 according to one alternative embodiment. The transmission 1 is adapted according to the transmission 1 described in Fig. 3b, with the difference that the transmission's 1 input shaft 14 is connected to the sun wheel 6 and the transmission's 1 output shaft 16 is connected to the ring gear 4 via a cogwheel 22 arranged at the output shaft 16. When the input shaft 14 and therefore the sun wheel 6 rotate in a first rotational direction, e.g. clockwise, the locking between the sun wheel 6 and the ring gear 4 entails that the ring gear 4 also rotates clockwise. The cogwheel 22 is arranged in engagement with the outer cogs of the ring gear 4 and thus rotates counterclockwise. Thus, a clockwise rotation of the input shaft 14 entails that the output shaft 16 rotates counterclockwise. When the input shaft 14 and the sun wheel 6 rotate in the second rotational direction, counter- clockwise in this example, the second freewheel 20 locks the planetary wheel carrier 10 to the static section 21 , so that the rotation of the planetary wheel carrier 10 is prevented. The first freewheel 18 no longer entails any locking between the ring gear 4 and the sun wheel 6. The placement and function of both freewheels 18, 20 thus entail that when the sun wheel 6 rotates counter- clockwise, the planetary wheels 8 rotate clockwise around their own shaft while the planetary wheel carrier 10 is stationary. This entails that the ring gear 4 also rotates clockwise which in turn entails that the cogwheel 22 rotates counterclockwise. Thus, a counterclockwise rotation of the input shaft 14 entails that the output shaft 16 also rotates counterclockwise. Thus, a transmission 1 is achieved which generates a specific rotational direction in its output shaft 16, regardless of the rotational direction of its input shaft 14.

Fig. 5 shows a schematic side view of a transmission 1 according to one embodiment of the present invention. The transmission 1 comprises a planetary gear 2 with a ring gear 4, a sun wheel 6, three planetary wheels 8 (only two displayed) and a planetary wheel carrier 10. Further, the transmission 1 comprises a cogwheel 12 arranged at the input shaft 14 of the transmission. The cog wheel 12 is arranged in engagement with external cogs arranged on the ring gear (not displayed) and operates the ring gear 4, and the input shaft 14 is thus connected to the ring gear 4. The output shaft 16 of the transmission 1 is arranged in connection with the sun wheel 6. Further, the input shaft 14 is connected to a driving device E, which consists of an electric motor. The out- put shaft 16 is connected to and operates a driven device P, which consists of an oil pump. A first coupling device 28 in the form of a friction coupling is arranged between and in connection with the ring gear 4 and the planetary wheel carrier 10. The first friction coupling 28 is arranged in connection with a control device 40 which controls the first friction coupling 28, so that it closes and connects the planetary wheel carrier 10 with the ring gear 4 at a first rotational direction of the input shaft 14. With the planetary wheel carrier 10 and the ring gear 4 connected, the ring gear 4, the planetary wheels 8, the planetary wheel carrier 10 and the sun wheel 6 rotate together in the same rotational direction. When the input shaft 14 and the cogwheel 12 rotate in a first rotational direction, the ring gear 4, and thus all of the components of the planetary gear 2, rotate in one rotational direction opposite to the first rotational direction of the input shaft 14. At a second rotational direction of the input shaft 14 the first friction coupling 28 allows for individual rotations of the planetary wheel carrier 10 and the ring gear 4. The first rotational direction and the second rotational direction are opposite to each other. Further, a second coupling device 30 in the form of a second friction coupling is arranged between and in connection with the planetary wheel carrier 10 and a static section 21 in relation to the planetary wheel carrier, e.g. a transmission house. The second friction coupling 30 is also arranged in connection with the control device 40 which controls the second friction coupling 30, so that it is open and allows the planetary wheel carrier 10 to rotate at the first rotational direction of the input shaft 14. The control device 40 also controls the second friction coupling 30, so that it is closed and locks the planetary wheel carrier 10 to the static section 21 and prevents rotation at the second rotational direction of the input shaft 14. The locking of the planetary wheel carrier 10 to the static section 21 entails that when the cogwheel 12 and the input shaft 14 rotate in the second rotational direction, the ring gear 4 rotates in an opposite direction while the planetary wheel carrier 10 is stationary. This entails that the planetary wheels 8 rotate around their own shaft in the same rotational direction as the ring gear 4, which in turn entails that the sun wheel 6 rotates in the same rotational direction as the cogwheel 12. Accordingly, a rotation in the second rotational direc- tion of the input shaft 14 leads to the output shaft 16 rotating in the same rotational direction as the input shaft 14. The control device 40 is arranged in connection with the electric motor E, so that the control device 40 is able to control the first friction coupling 28 and the second friction coupling 30 depending on the electric motor's E rotational direction. Thus, a transmission 1 is achieved which generates a specific rotational direction in its output shaft 16, regardless of the rotational direction of its input shaft 14.

Fig. 6 shows a schematic side view of a vehicle 100 comprising a transmission 1 according to the present invention. The vehicle 100 also comprises a combustion engine 200 connected to a gearbox 300, which comprises the transmission 1 . The gearbox 300 also comprises a transmission house 400, which may consist of the static section 21 .

The components and features specified above may, within the framework of the invention, be combined between different embodiments specified.