Method for operating a motor vehicle transmission pump

Abstract

Method for operating a motor vehicle transmission pump (15) which is connected to an electric machine (1) by means of a summing gear (14) and which is connected or connectable to a drive unit (16) by means of the summing gear (14), wherein a brake (6) is selectively switched to a first switching state or a second switching state, wherein the electric machine (1) in the first switching state is selectively operated either in motor mode, in which the motor vehicle transmission pump (15) is at least partially driven by the electric machine (1), or in generator mode, in which the motor vehicle transmission pump (15) and the electric machine (1) are driven by means of the drive unit (16),is operated and wherein in the second switching state the motor vehicle transmission pump (15) is driven solely by the drive device (16) and the summing transmission (14) is supported by means of the brake (6) characterized in that in the second switching state of the brake (6) the summing transmission (14) is mechanically supported by means of the brake (6) and the actuating means (11) , a. to transfer the brake (6) into the second switching state and / or b. to transfer the brake (6) to the first switching state, and the actuating means (11) is not energized when the speed of the drive shaft (30) is less than the minimum speed (n1) of the drive shaft (30).

Description

[0001] The invention relates to a method for operating a motor vehicle gear pump which is drive-technically connected to an electric machine by means of a summing gear and which is drive-technically connected or connectable to a drive device by means of the summing gear.

[0002] Furthermore, the invention relates to a motor vehicle transmission with an electric machine, a summing gear which is drivingly connected to a rotor shaft of the electric machine and can be drivingly connected to a drive device, a motor vehicle transmission pump which is drivingly connected to an output shaft of the summing gear and a brake.

[0003] A variety of motor vehicle transmissions are known from the prior art, which have a motor vehicle transmission pump arranged within a cavity of the motor vehicle transmission for pumping oil. It is known that the motor vehicle transmission pump can be driven by two separate drive devices. One drive device can comprise an internal combustion engine, an electric motor, or a hybrid drive, wherein the drive device is or can be connected to the motor vehicle transmission pump by means of a gear set and a summing gear. Another drive device can comprise another electric motor, which is connected to the motor vehicle transmission pump by means of the summing gear.

[0004] DE 10 2011 013 487 A1 discloses a design in which a freewheel is provided on a sun shaft with support in the housing. A disadvantage of this design is that operating the electric motor in generator mode is not possible. Furthermore, controlling the pump speed across the entire speed range of the drive device, especially the combustion engine, is only possible to a limited extent.

[0005] US 2004 / 0 112 654 A1 describes a vibration damping device for reducing torsional resonance vibration in a hybrid vehicle, wherein, among other things, the inertia of the transmission arrangement and the combustion engine is coupled to the inertia of the electric motor via spring elements.

[0006] DE 103 29 215 A1 describes a drive device for a transmission oil pump with a constant displacement volume for supplying any transmission, wherein the drive device has two power trains, one power train being driven by an internal combustion engine and the other power train being driven by an electric motor.

[0007] DE 687 644 A describes an electric motor with an electromagnetically controlled brake located within the brake-side bearing plate, which closes off the brake chamber to the outside. The brake's control magnet is supported by a flange body. The flange body is attached to the hub of a standard bearing plate that accommodates the shaft bearing.

[0008] The disadvantage of the current design is that the electric motor cannot be operated on demand. However, this is advantageous for reasons such as fuel savings and is therefore often desired by vehicle manufacturers.

[0009] The object of the invention is therefore to provide a method for operating a motor vehicle transmission pump in which the electric machine can be operated as needed.

[0010] This object is achieved by a method of the type mentioned at the outset, which is characterized in that a brake is selectively switched into a first switching state or a second switching state, wherein in the first switching state the electric machine is operated selectively in a motor mode, in which the motor vehicle transmission pump is driven at least partially by means of the electric machine, or in a generator mode, in which the motor vehicle transmission pump and the electric machine are driven by means of the drive device, and wherein in the second switching state the motor vehicle transmission pump is driven solely by the drive device and the summing gear is supported by means of the brake.

[0011] The object of the invention is also to provide a motor vehicle transmission in which the electric machine can be operated as needed when driving the motor vehicle transmission pump.

[0012] The object is achieved by a motor vehicle transmission of the type mentioned at the outset, which is characterized in that the brake can be selectively switched into a first switching state or a second switching state, wherein in the first switching state the electric machine can be operated selectively in a motor operation, in which the motor vehicle transmission pump can be driven at least partially by means of the electric machine, or in a generator operation, in which the motor vehicle transmission pump and the electric machine can be driven by means of the drive device, and wherein in the second switching state the motor vehicle transmission pump can be driven solely by the drive device and the summing transmission can be supported by means of the brake.

[0013] The provision of the brake, which can be switched to either the first switching state or the second switching state, offers the advantage that the electric machine can be operated as needed. Thus, when the brake is in the first switching state, the electric machine can be operated in motor or generator mode. Alternatively, when the brake is in the second switching state, the motor vehicle transmission pump can be operated solely by the drive device. This means that when the brake is in the second switching state, the electric machine is not operated. As a result, demand-dependent operation of the electric machine can be achieved in a simple manner and / or the electric machine can be used in a variety of ways.

[0014] The provision of the brake also has the advantage that freewheels are not required to drive the motor vehicle transmission pump; instead, the switching state of the brake determines whether the electric motor can drive the motor vehicle transmission pump or not. This offers the advantage that the electric motor does not have to be constantly dragged along if the motor vehicle transmission pump is driven solely by the drive device. Furthermore, no complex engine control system is required to regulate the electric motor. Furthermore, if the electric motor fails, the motor vehicle transmission pump will not fail.

[0015] Furthermore, the electric motor can be immobilized at any time using the brake, regardless of whether it is operating in motor or generator mode. Using the switchable brake also makes it possible to suspend recuperation processes at times when no electrical consumers require electrical energy. Furthermore, demand-based recuperation is possible in areas where the oil flow rate is oversaturated. In particular, electrical energy can be supplied to electrical consumers of the vehicle transmission, for example, to reduce the transmission's electrical power consumption. This can reduce fuel consumption.Furthermore, due to the use of the switchable brake, it is possible to disconnect the electrical branch in the event of a failure of the electrical machine or its control and to drive the motor vehicle transmission pump exclusively mechanically, in particular by means of the drive device, which leads to a higher level of fail-safe protection.

[0016] The electric machine consists of at least a stator and a rotatably mounted rotor. It is designed to convert electrical energy into mechanical energy in the form of speed and torque in motor mode, and to convert mechanical energy into electrical energy in the form of current and voltage in generator mode. The rotor can be non-rotatably connected to the rotor shaft and / or attached to the rotor shaft.

[0017] The brake can be a switchable and / or a mechanical brake. With a mechanical brake, the braking effect is achieved solely by mechanical components. The mechanical components can be a coupling element, described in more detail below, or another coupling element, described in more detail below. The brake can be switched to the open and / or closed state using an actuating device, described in more detail below.

[0018] The drive device can comprise an internal combustion engine and / or another electric motor. The motor vehicle transmission pump serves to pump oil within the motor vehicle transmission.

[0019] In a special embodiment, a pump drive can be implemented such that the motor vehicle transmission pump is driven by the electric machine and the drive device. In particular, when the pump drive is operating in the first switching state of the brake, a speed of a drive shaft of the drive device and / or a speed of a rotor shaft of the electric machine can be set such that a speed of a pump shaft of the motor vehicle transmission pump remains constant. In particular, the speed of the rotor shaft of the electric machine can be adapted to the speed of the drive shaft of the drive device. This is often necessary because the speed of the drive shaft of the drive device is specified by the vehicle manufacturer.As a result, by adjusting the speed of the rotor shaft and / or the speed of the drive shaft relative to each other, it can be achieved in a simple manner that the speed of the pump shaft of the motor vehicle transmission pump remains constant during operation of the motor vehicle transmission pump.

[0020] The speed of the drive shaft and / or the speed of the rotor shaft can be adjusted both in generator and motor mode of the electric machine. In particular, the speed of the rotor shaft and the speed of the drive shaft can change in opposite directions both in motor and generator mode. In particular, a drop in the speed of the rotor shaft can be associated with an increase in the speed of the drive shaft. The speed of the pump shaft of the motor vehicle transmission pump can be selected such that the motor vehicle transmission pump delivers a sufficiently high oil volume flow to supply the motor vehicle transmission with oil.The advantage of the operating mode described above in the first switching state of the brake is that the surplus power available from the drive device, i.e. the power that is not required by the motor vehicle transmission pump to pump oil, can be converted into electrical energy by means of the electric machine.

[0021] A shaft is not exclusively understood to mean, for example, a cylindrical, rotatably mounted machine element for transmitting torque, but rather also general connecting elements that connect individual components or elements to one another, in particular connecting elements that connect several elements to one another in a rotationally fixed manner.

[0022] The directions “axial” and “radial” refer to a central axis of the electrical machine, unless otherwise stated.

[0023] The electrical energy generated during generator operation of the electric machine can be supplied to at least one consumer of a motor vehicle transmission and / or a motor vehicle electrical system. Thus, the excess power provided by the drive device can be used to supply electrical power, in particular to all electrical consumers of the motor vehicle transmission. If more electrical energy is generated than is required to operate the electrical consumers of the motor vehicle transmission, the electrical energy can be fed into the vehicle electrical system.

[0024] In another operating mode of the pump drive, the speed of the rotor shaft of the electric machine can be kept constant when the brake is first switched and the electric machine is operating as a generator, while the speed of a drive shaft of the drive device is increased. This can be achieved by energizing the stator of the electric machine in such a way that a counterforce is exerted on the rotor shaft, which prevents the speed of the rotor shaft from increasing. In this operating mode, only a portion of the surplus power available from the drive device can be converted into electrical energy by the electric machine. The motor operation of the electric machine can also take place in the other operating mode of the pump drive, as described in more detail above.

[0025] In the other operating mode of the pump drive, the electric motor's generator operation can only generate enough electrical energy to supply at least one electrical consumer, in particular all electrical consumers, of the vehicle transmission with electrical energy. In this operating mode, no electrical energy is supplied to the vehicle's electrical system.

[0026] In a further operating mode of the pump drive, the brake can be transferred to the second switching state at an actuation time at which a drive shaft of the drive device has a minimum speed. The minimum speed of the drive shaft of the drive device corresponds to the speed of the drive shaft at which the motor vehicle transmission pump has a sufficiently high speed so that the motor vehicle transmission pump can deliver the oil volume flow required to supply the motor vehicle transmission. From the minimum speed onwards, the motor vehicle transmission pump can be driven solely by the drive unit without there being a risk that the motor vehicle transmission pump will deliver too low an oil volume flow. This means that once the minimum speed of the drive shaft is reached, the electric machine is no longer operated and therefore the rotor shaft does not rotate.In this mode of operation, the electric motor is only operated in motor mode. Motor mode can occur as described above. The minimum speed of the drive shaft of the drive unit can have different values ​​for different operating conditions of the motor vehicle transmission pump, such as different torques and / or system pressures.

[0027] In the second switching state, the summing gear is mechanically supported by the brake. This means that the summing gear is supported solely by mechanical components and therefore not by an electromagnetic force applied by the electric motor. This eliminates the need to energize the electric motor to support the summing gear.

[0028] The brake is switched to the first, in particular open, switching state or a second, in particular closed, switching state by means of an actuating means. The actuating means is energized to apply the brake. The brake is released when the actuating means is not energized. The actuating means is not energized if the speed of the drive shaft is lower than the minimum speed of the drive shaft. This provides a simple way to ensure that the speed of the motor vehicle transmission pump does not fall below a minimum value, thus ensuring the oil supply to the motor vehicle transmission.

[0029] The brake can be designed such that, when the brake is applied, the brake prevents the rotor shaft of the electric machine from rotating at the time of application. When the brake is applied, the brake can be closed. However, the brake does not prevent the rotor shaft from rotating when the brake is not applied. In this case, the brake is open.

[0030] The actuating means can be an electromagnet or comprise an electromagnet. In particular, the actuating means can comprise a coil, which can be wound with its own winding having two winding ends. The coil can be energized via the electronics of the electric machine. Energization of the actuating means can depend on a power limit of the electric machine, an on-board power system requirement of the motor vehicle in which the electric machine is installed, a power requirement of a transmission-internal control system, and / or aspects for increasing availability or functional safety.

[0031] The actuating means can be arranged offset from the stator. In particular, the actuating means can be arranged axially offset from the stator and / or the rotor. The actuating means can have the same sheet metal cross-section as the stator. This allows for simple manufacturing of the actuating means. A portion of the actuating means, in particular the sheet metal cross-section, can be connected to the housing in a rotationally fixed manner. Furthermore, the actuating means can be energized independently of the stator.

[0032] The brake can have a coupling element that is movable relative to the rotor of the electric machine, wherein the brake is in the second switching state when the coupling element is in a first position and the brake is in the first switching state when the coupling element is in a second position. The coupling element can be connected to the rotor shaft in a rotationally fixed manner. Furthermore, the coupling element can be arranged so as to be movable in the axial direction relative to the rotor shaft and / or the rotor. The coupling element can be connected to the rotor shaft by means of a sliding toothing. Furthermore, the coupling element can be arranged coaxially to the rotor shaft. Furthermore, the coupling element can be arranged centrally to the actuating means in the first position.

[0033] A rotationally fixed connection is defined as a connection between two components that is designed and arranged in such a way that the two interconnected components always have the same rotational speed. This is not the case, for example, if a switching element is arranged between the two interconnected components and is in the open state.

[0034] The rotor shaft can extend through a housing of the electric machine. The housing can at least partially enclose a cavity in which the stator and / or the rotor are arranged. Furthermore, the rotor shaft can be supported on the housing, in particular directly, by means of at least one bearing. In particular, the rotor shaft can be supported on the housing, in particular directly, by means of exactly two bearings. The brake can be arranged within the cavity. Furthermore, the actuating means can be arranged within the cavity.

[0035] The brake can further comprise the other coupling element for a rotationally fixed connection to the coupling element. The other coupling element can be rotationally fixedly connected to the housing of the electric motor or the motor vehicle transmission. Furthermore, the other coupling element can be rotationally fixedly connected to the coupling element when the brake is engaged. The coupling element and the other coupling element can be connected to each other frictionally and / or positively. The rotationally fixed connection between the coupling element and the other coupling element can be realized independently of the direction of rotation of the rotor shaft.

[0036] The coupling element can move relative to the rotor shaft and / or the rotor when moving from the first position to the second position or vice versa. There is no axial movement of the rotor shaft and / or the rotor, which allows for a compact design of the electric machine. In particular, it is not necessary to provide space to accommodate the displaced rotor shaft and / or the displaced rotor. However, the rotor and / or the rotor shaft can rotate.

[0037] The brake can be engaged by moving the coupling element from the second position to the first position. Thus, apart from moving the coupling element from the second position to the first position, no further measures are necessary to create the rotationally fixed connection between the coupling element and the other coupling element. The brake can be released by moving the coupling element from the first position to the second position. Here, too, apart from moving the coupling element from the first position to the second position, no further measures are necessary to release the rotationally fixed connection between the coupling element and the other coupling element. As a result, the brake can be engaged or disengaged in a simple manner.

[0038] The coupling element can be actuated by the actuating means such that the coupling element moves from the first position to the second position. Alternatively or additionally, the coupling element can be actuated by the actuating means such that the coupling element moves from the second position to the first position. To actuate the coupling element by means of the actuating means, the actuating means can be energized. As a result of energizing the actuating means, an electromagnetic force is generated that acts on the coupling element and causes the coupling element to be displaced into the first or second position.

[0039] The electric machine can have a reset element that is operatively connected to the coupling element. The reset element can exert a force on the coupling element that is directed towards the second position. In particular, the reset element can be designed and arranged such that it moves the coupling element from the first position to the second position when the actuating means is not energized. The reset element can be designed as a spring, for example. The reset element can easily ensure that the rotor is moved into the second position when the actuating means is not energized. In contrast, when the actuating means is energized, the resulting electromagnetic force can be greater than the force applied by the reset element, so that the coupling element moves into the first position. When the rotor is moved into the first position, the reset element can be tensioned.

[0040] The return element can be supported at one end on the coupling element, in particular directly. Furthermore, the return element can be supported at another end, in particular indirectly, on the rotor shaft. In particular, the other end of the return element can be supported on the rotor shaft by means of a disk.

[0041] The electronics of the electric machine can include a control unit that energizes the actuating means. This means that the control unit energizes the actuating means or initiates energization of the actuating means. The control unit can decide when the actuating means should be energized. The control unit can be attached to a circuit board of the electronics and / or electrically connected to the circuit board. Furthermore, the electronics can include a communication means for communicating with a control unit of the motor vehicle transmission and / or a control unit of a motor vehicle electrical system.

[0042] The communication means communicates with a control unit of the motor vehicle transmission and / or with a control unit of the motor vehicle electrical system. In particular, the control unit of the motor vehicle transmission and / or the control unit of the motor vehicle electrical system can inform the communication means whether electrical consumers in the motor vehicle transmission require electrical energy and / or whether electrical energy can be fed into the vehicle electrical system. Depending on this information, the electric machine can be operated in such a way that the actually required amount of electrical energy is generated. The communication means can be a software program installed in the electronics of the electric machine.

[0043] Also advantageous is a motor vehicle transmission with a control unit that is designed to carry out a method according to the invention. In addition to or alternatively to the components described above, the motor vehicle transmission can have at least one gear set that has at least two, in particular exactly two or three, gears. The drive device not belonging to the motor vehicle transmission can be drivingly connected or connectable to the summing gear by means of the gear set. The gears can be spur gears. In a design that has two gears, the two gears can be in mesh with one another. In a design that has three gears, an intermediate gear can be present that is in mesh with the two remaining gears.

[0044] Alternatively, the drive device can be connected to the summing gear by means of a traction drive or can be connected to it by means of a traction drive. The traction drive can comprise at least two gears and a traction mechanism, such as a chain. The two gears can be connected to each other by means of the traction mechanism.

[0045] The rotor shaft of the electric motor can be non-rotatably connected to a component of the summing gear. The component of the summing gear is mechanically supported by the rotor shaft when the brake is applied. In this case, the motor vehicle transmission pump can be driven solely by the drive device, without the electric motor having to be dragged along. Furthermore, no axial forces are transmitted from the actuating means and / or the coupling element and / or the other coupling element to the rotor, or vice versa.

[0046] The drive device can be connected or connectable to another component of the summing gear. The output shaft of the summing gear can be connected in a rotationally fixed manner to another component of the summing gear. Furthermore, the output shaft can be connected in a rotationally fixed manner to the motor vehicle transmission pump, in particular directly. In particular, the output shaft can be connected in a rotationally fixed manner to a pump shaft of the motor vehicle transmission pump. The summing gear can have one, in particular a single, planetary gear set.

[0047] The drive unit can be connected to the summing gear via the gear set. This is the case if a coupling is arranged between the drive unit and the gear set. Alternatively, the drive unit can be connected to the summing gear via the gear set if no coupling is arranged between the drive unit and the gear set.

[0048] The motor vehicle transmission may also include a gearbox. A gearbox input shaft of the gearbox may be connected to the gear set or the traction drive by means of a drive element, or may be connectable, for example, by means of a shifting element. The gearbox may have several other gear sets and / or several other shifting elements, by means of which different gears with different ratios can be implemented between the gearbox input shaft and a gearbox output shaft of the gearbox. The gearbox input shaft may be connected to the other gear sets by means of a drive element, or may be connectable by means of a drive element. Furthermore, the different gears can be implemented by engaging another shifting element or several other shifting elements.

[0049] Furthermore, a motor vehicle with the drive device and a motor vehicle transmission according to the invention is advantageous. The drive device can be connected to the motor vehicle transmission pump for driving purposes. In another motor vehicle, the drive device can be connected to the motor vehicle transmission pump for driving purposes by means of the clutch.

[0050] The subject matter of the invention is illustrated schematically in the figures and is described below with reference to the figures, wherein identical or equivalent elements are generally provided with the same reference numerals. Herein: Fig. 1 an electrical machine with a coupling element arranged in a first position, Fig. 2 the electric machine with the coupling element arranged in a second position, Fig. 3 an enlarged view of a section between the coupling element and an actuating means of the electrical machine, Fig. 4 a motor vehicle transmission according to the invention according to a first embodiment, Fig. 5 a motor vehicle transmission according to the invention according to a second embodiment, Fig. 6 a motor vehicle transmission according to the invention according to a third embodiment, Fig. 7 is a diagram showing the operating range of the electrical machine, Fig. 8 shows a speed curve of the electric machine, the drive shaft and the motor vehicle transmission pump during an operating mode of a pump drive of the motor vehicle transmission, Fig. 9 a speed curve of the electric machine, the drive shaft and the motor vehicle transmission pump in a different operating mode of the pump drive of the motor vehicle transmission, Fig. 10 shows a speed curve of the electric machine, the drive shaft and the motor vehicle transmission pump in a further operating mode of the pump drive of the motor vehicle transmission.

[0051] Fig. Figure 1 shows an electrical machine 1 with a stator 3, a housing 4, which partially encloses a cavity 5, and a rotor 2. The stator 3 and the rotor 2 are arranged within the cavity 5. The rotor 2 is connected to a rotor shaft 9 for driving purposes. In particular, the rotor 2 is connected to the rotor shaft 9 in a rotationally fixed manner. Fig. 1 only an upper part of the electrical machine 1.

[0052] A brake 6 is arranged within the cavity 5. The brake 6 has a coupling element 7, which is connected to the rotor shaft 9 by means of a sliding toothing 19 in such a way that the coupling element 7 is movable in the axial direction with respect to a central axis 20 of the electric machine 1 relative to the rotor shaft 9 and the rotor 2. In addition, the coupling element 7 is connected to the rotor shaft 9 in a rotationally fixed manner. In a first position of the coupling element 7, the brake 6 is closed. In a second position of the coupling element 7, the brake 6 is opened. The rotor shaft 9 is connected to a Fig. 4 shown summing gear 14.

[0053] The stator 3 is arranged further away in the radial direction from the central axis 20 than the rotor 2. The stator 3 is connected to the housing 4 in a rotationally fixed manner. The stator 3 and the rotor 2 are arranged and designed such that they cannot move along the central axis 20. The rotor shaft 9 cannot move along the central axis 20 either.

[0054] When the brake 6 is in the closed switching state, Fig. 1, the coupling element 7 is connected in a rotationally fixed manner to another coupling element 8 of the brake 6. The other coupling element 8 is connected in a rotationally fixed manner to the housing 4 and / or is formed integrally with the housing 4. When the brake 6 is in the closed switching state, the rotor shaft 9 and thus the rotor 2 cannot rotate. Thus, Fig. 4 visible summing gear 14 resulting torques are supported by means of the rotor shaft 9, the coupling element 7, the other coupling element 8 and the housing 4.

[0055] The electric machine 1 has an actuating means 11 in the form of an electromagnet, which is arranged in the cavity 5. The actuating means 11 is arranged offset in the axial direction to the stator 3. Furthermore, a part of the actuating means 11 is connected to the housing 4 in a rotationally fixed manner. Fig. In the state of the electrical machine 1 shown in Figure 1, the electrical machine 1, in particular the actuating means 11 of the electrical machine 1, is energized. The electromagnetic force resulting from the energization holds the coupling element 7 in the first position.

[0056] The rotor shaft 9 is supported on the housing 4 via two bearings 10. Furthermore, the rotor shaft 9 extends through the housing 4. In particular, the end of the rotor shaft 9 extends through the housing 4, which is rotationally fixedly connected to a component of the summing gear 14.

[0057] The electric machine 1 has a return element 12. The return element 12 is designed as a spring, which is supported at one end on the coupling element 7. In the Fig. In the state of the electrical machine 1 shown in Figure 1, the reset element 12 is tensioned. The reset element 12 is supported at the other end on a disc 21.

[0058] Fig. Figure 2 shows the electric machine 1 with the coupling element 7 arranged in a second position. In the second position, the coupling element 7 is no longer rotationally fixedly connected to the other coupling element 8. This means that the brake 6 is in an open state. The return element 12 presses the coupling element 7 out of the Fig. 1 shown first position into the one shown in Fig. 2. When transferred from the first position to the second position, the coupling element 7 moves in a direction away from the other coupling element 8. In the second position, the electric machine 1 can be motor-driven. To move the coupling element 7 from the first position to the second position, the actuating means 11 is no longer energized, so that no electromagnetic force acts on the coupling element 7 that is greater than the force exerted on the coupling element 7 by the return element 12.

[0059] Fig. 3 shows an enlarged view of a Fig. 2 shown section A between the actuating means 11 and the coupling element 7. From Fig. 3 shows the course of magnetic field lines 42 between the actuating means 11 and the coupling element 7. In addition, Fig. Figure 3 shows the course of a force 43 acting on the coupling element 7. The force 43 has an axial and a radial component.

[0060] When the actuating means 11 is not energized, the spring force exerted by the return element 12 on the coupling element 7 is large enough to move the coupling element 7 from the first position to the second position. When the actuating means 11 is energized, the axial component of the force 43 is greater than the spring force of the return element 12, so that the coupling element 7 moves from the second position to the Fig. 1 shown first position.

[0061] Fig. 4 shows a motor vehicle transmission 13 according to a first exemplary embodiment. The motor vehicle transmission 13 has the electric machine 1, which is drivingly connected to the motor vehicle transmission pump 15 by means of the summing gear 14. The motor vehicle transmission pump 15, in particular a pump shaft of the motor vehicle transmission pump 15, is drivingly connected to the output shaft 23 of the summing gear 14. The summing gear 14 is also drivingly connectable to a drive device 16 by means of a gear set 17. In particular, a drive shaft 30 of the drive device 16 is rotationally fixedly connected to the summing gear 14 by means of a coupling 24.

[0062] The gear set 17 has a first gear 25, an intermediate gear 26, and a second gear 27. The first gear 25 meshes with the intermediate gear 26. The intermediate gear 26 also meshes with the second gear 27. The second gear 27 is directly connected to the summing gear 14. Furthermore, the second gear 27 is supported by a bearing on a housing G of the motor vehicle transmission 13. The summing gear 14 can have a planetary gear set (not shown in the figures). In this case, the rotor shaft 9 is rotationally fixedly connected to one component of the planetary gear set, in particular a sun gear. The second gear 27 is rotationally fixedly connected to another component of the planetary gear set, in particular a ring gear. The output shaft 23 is rotationally fixedly connected to another component of the planetary gear set, in particular a carrier.

[0063] The motor vehicle transmission 13 also has a gear 28. The transmission 28 has several other gear sets and / or other shifting elements (not shown in the figures) for implementing different gears with different ratios. The first gear 25 is rotationally fixedly connected to a transmission input shaft 29 of the transmission 28. The transmission input shaft 29 can also be rotationally fixedly connected to the drive shaft 30 by means of the clutch 24.

[0064] The motor vehicle transmission pump 15 can be driven by the drive device 16 alone. In this case, the coupling element 7 is arranged in the second position. Furthermore, the motor vehicle transmission pump 15 can be operated jointly by the drive device 16 and the electric machine 1 or solely by the electric machine 1. The motor vehicle transmission 13 and the drive device 16 can be part of a motor vehicle 18.

[0065] Fig. 5 shows a motor vehicle transmission 13 according to a second embodiment. The motor vehicle transmission 13 according to the second embodiment differs from that shown in Fig. 4 in the design of the gear set 17. The gear set 17 differs in that there is no intermediate gear 26. This means that the first gear 25 is in mesh with the second gear 27.

[0066] Fig. 6 shows a motor vehicle transmission 13 according to a third embodiment. Fig. In the motor vehicle transmission 13 shown in Figure 6, the summing gear 14 is designed as a planetary gear set. Fig. 6 shows a transmission output shaft 39, which is connected to components not shown in the figures, such as a differential, and electronics 35 of the electric machine 1.

[0067] The electronics system 35 includes a control unit 36, a circuit board 40 electrically connected to the control unit 36, and a communication means 37. The communication means 37 communicates with the control unit 36, a control unit 38 of the motor vehicle transmission 13, and a control unit of a motor vehicle electrical system 34. The control unit 36 ​​can energize the actuating means 11, as shown by the dashed line, and thus close the brake 6.

[0068] The control unit 38 of the motor vehicle transmission and / or the control unit of the motor vehicle electrical system 34 inform the communication device 37, among other things, whether an electrical consumer of the motor vehicle transmission 13 and / or the motor vehicle 18 requires electrical energy. The communication device 37 communicates this information to the control unit 36, so that the control unit 36 ​​decides which switching state the brake 6 should be switched to. Furthermore, the control unit 36 ​​decides how the electric machine 1 should be operated.

[0069] Fig. Figure 7 shows the operating range of electric machine 1. The torque M is plotted vertically, and the speed n is plotted horizontally. Electric machine 1 can be operated in motor mode in quadrants I and III. Conversely, electric machine 1 can be operated in generator mode in quadrants II and IV. Furthermore, electric machine 1 can be stopped from all situations by brake 6.

[0070] Fig. Figure 8 shows a speed curve 31 of the rotor shaft 9 of the electric machine 1, a speed curve 32 of the drive shaft 30 of the drive device 16, and a speed curve 33 of the pump shaft of the motor vehicle transmission pump 15 over time t during one operating mode of a pump drive of the motor vehicle transmission. During this operating mode, the electric machine 1 is operated in motor and generator mode. The speed n of the respective component is plotted vertically, and time t is plotted horizontally.

[0071] As from Fig. 8, the speed of the rotor shaft 9 and / or the speed of the drive shaft 30 is set at all times such that the speed of the pump shaft is constant. At a starting time t0, only the rotor shaft 9 of the electric machine 1 has a speed greater than zero. The speed of the rotor shaft 9 is so high that a speed of a pump shaft of the motor vehicle transmission pump 15 is established that is sufficient for supplying oil to the motor vehicle transmission 13. The speed of the rotor shaft 9 of the electric machine 1 decreases linearly from the starting time t0. In contrast, the speed of the drive shaft 30 increases linearly from a value of zero over time from the starting time t0.

[0072] The electric machine 1 is in motor operation until a time t1. From time t1 onwards, the electric machine 1 is in generator operation. This means that the surplus power of the drive device 16, the level of which is Fig. 8, correlates with the vertical distance between the rotational speed of the drive shaft 30 and the rotational speed of the motor vehicle pump 15, is converted into electrical energy in the electric machine 1. The generated electrical energy is supplied to other electrical consumers (not shown) of the motor vehicle transmission 13 or fed into the vehicle electrical system 34.

[0073] Fig. Figure 9 shows a speed curve 31 of the rotor shaft 9 of the electric machine 1, a speed curve 32 of the drive shaft 30 of the drive device 16, and a speed curve 33 of the pump shaft of the motor vehicle transmission pump 15 over time t for a different operating mode of the pump drive of the motor vehicle transmission 13. In the different operating mode, only a portion of the excess power of the drive device 16 is converted into electrical energy. Only enough electrical energy is generated to supply the electrical consumers of the motor vehicle transmission 13 with electrical energy. Thus, no electrical energy is fed into the motor vehicle electrical system 34.

[0074] The electrical machine 1 is analogous to the one in Fig. 8, the electric machine 1 is operated in generator mode from time t1. However, from a different time t2, the electric machine 1 is operated such that the speed of the rotor shaft 9 is kept constant. The portion of the surplus power of the drive device 16 that is not converted into electrical energy causes the speed of the pump shaft of the motor vehicle transmission pump 15 to increase from the different time t2.

[0075] In addition, Fig. 9 shows a minimum speed 41 of the motor vehicle transmission pump 15, which is required so that the motor vehicle transmission pump 15 can deliver the oil volume flow required for the oil supply to the motor vehicle transmission 13.

[0076] Fig. 10 shows a speed curve 31 of the rotor shaft 9 of the electric machine 1, a speed curve 32 of the drive shaft 30 of the drive device 16, and a speed curve 33 of the pump shaft of the motor vehicle transmission pump 15 over time t in a further operating mode of a pump drive of the motor vehicle transmission 13. In this further operating mode, generator operation of the electric machine 1 is not possible. This operating mode is useful, for example, when neither the motor vehicle electrical system 34 nor an electrical consumer of the motor vehicle transmission 13 requires electrical energy.

[0077] As from Fig.10, the brake 6 is closed at an actuation time t3. From the actuation time t3, the rotor shaft 9 of the electric machine 1 no longer rotates. At the actuation time t3, the speed of the drive shaft 30 corresponds to a minimum speed n1. The minimum speed n1 has such a high value that a speed of the pump shaft of the motor vehicle transmission pump 15 is established at which a sufficiently high

[0078] Oil volume flow can be pumped through the motor vehicle transmission pump 15 to supply the motor vehicle transmission 13 with oil. From the actuation time t3, the motor vehicle transmission pump 15 can be driven solely by the drive device 16.

[0079] The electric machine 1 is operated as a motor between the starting time t0 and the actuation time t3. From the actuation time t3 onward, the speed of the motor vehicle transmission pump 15 increases and the rotor shaft 9 does not rotate. Reference symbol 1 electric machine 2 rotors 3 Stator 4 Housing of the electrical machine 5 Cavity 6 Brake 7 Coupling element 8 other coupling element 9 Rotor shaft 10 warehouses 11 Actuating means 12 Reset element 13 Motor vehicle transmissions 14 summing gears 15 Automotive transmission pump 16 Drive device 17 wheelset 18 Motor vehicle 19 Sliding gearing 20 Central axis 21 disc 23 Output shaft 24 Clutch 25 first gear 26 intermediate gear 27 second gear 28 gearboxes 29 Gearbox input shaft 30 drive shaft 31 Speed ​​curve of the rotor shaft of the electric machine, 32 Speed ​​curve of the drive shaft of the drive device 33 Speed ​​curve of the automotive transmission pump 34 Vehicle electrical system 35 Electronics 36 Control unit 37 means of communication 38 Control unit of the motor vehicle transmission 39 Gearbox output shaft 40 boards 41 Minimum speed of the pump shaft of the motor vehicle transmission pump 42 magnetic field lines 43 power Section A G Housing of the motor vehicle gearbox n speed t time n1 Minimum speed t0 start time t1 time point t2 other time t3 Actuation time

Claims

[1] Method for operating a motor vehicle transmission pump (15) which is drivingly connected to an electric machine (1) by means of a summing gear (14) and which is drivingly connected or connectable to a drive device (16) by means of the summing gear (14), wherein a brake (6) is selectively switched into a first switching state or a second switching state, wherein the electric machine (1) in the first switching state is selectively operated in a motor mode, in which the motor vehicle transmission pump (15) is driven at least partially by means of the electric machine (1), or in a generator mode, in which the motor vehicle transmission pump (15) and the electric machine (1) are driven by means of the drive device (16),is operated and wherein in the second switching state the motor vehicle transmission pump (15) is driven solely by the drive device (16) and the summing gear (14) is supported by means of the brake (6), characterized by that in the second switching state of the brake (6) the summing gear (14) is mechanically supported by means of the brake (6) and the actuating means (11) a. to transfer the brake (6) into the second switching state and / or b. to transfer the brake (6) into the first switching state, no current is supplied, and the actuating means (11) is not supplied with current when the speed of the drive shaft (30) is lower than the minimum speed (n1) of the drive shaft (30). [2] Method according to claim 1, characterized by , that a. in the first switching state of the brake (6), a speed of a drive shaft (30) of the drive device (16) and / or a speed of a rotor shaft (9) of the electric machine (1) are set such that a speed of a pump shaft of the motor vehicle transmission pump (15) remains constant or that b. in the first switching state of the brake (6) and during generator operation of the electrical machine (1), a speed of a rotor shaft (9) of the electrical machine (1) is kept constant, while a speed of a drive shaft (30) of the drive device (16) is increased, or that c. that the brake (6) is transferred to the second switching state at an actuation time (t3) at which a drive shaft (30) of the drive device (16) has a minimum speed (n1). [3] Method according to claim 1 or 2, characterized by , that a. an electrical energy generated during generator operation of the electrical machine (1) is supplied to at least one electrical consumer of a motor vehicle transmission (13) and / or a motor vehicle electrical system (34) and / or that b. during generator operation of the electrical machine (1), only so much electrical energy is generated that at least one electrical consumer of a motor vehicle transmission (13) is supplied with electrical energy. [4] Method according to one of claims 1 to 3, characterized by that in the second switching state of the brake (6) the summing gear (14) is mechanically supported by means of the brake (6). [5] Method according to one of claims 1 to 4, characterized by that in the second switching state of the brake (6) rotation of a rotor shaft (9) of the electrical machine (1) is prevented by means of the brake (6). [6] Motor vehicle transmission (13) with a control unit (36, 38) which is designed to carry out a method according to one of claims 1 to 5. [7] Motor vehicle transmission (13) with an electric machine (1), a summing gear (14) which is drivingly connected to a rotor shaft (9) of the electric machine (1) and can be drivingly connected to a drive device (16), a motor vehicle transmission pump (15) which is drivingly connected to an output shaft (23) of the summing gear (14) and a brake (6), characterized byin that the brake (6) can be switched selectively into a first switching state or a second switching state, wherein in the first switching state the electric machine (1) can be operated selectively in a motor operation, in which the motor vehicle transmission pump (15) can be driven at least partially by means of the electric machine (1), or in a generator operation, in which the motor vehicle transmission pump (15) and the electric machine (1) can be driven by means of the drive device (16), and wherein in the second switching state the motor vehicle transmission pump (15) can be driven solely by the drive device (16) and the summing gear (14) can be supported by means of the brake (6). [8] Motor vehicle transmission (13) according to claim 6 or 7, characterized byin that the brake (6) has a coupling element (7) which is movable relative to a rotor (2) of the electrical machine (1), wherein the brake (6) is in the second switching state when the coupling element (7) is in a first position and is in the first switching state when the coupling element (7) is in a second position. [9] Motor vehicle transmission (13) according to claim 8, characterized by , that a. the coupling element (7) is connected to the rotor shaft (9) in a rotationally fixed manner and / or that b. the coupling element (7) is movable in the axial direction relative to the rotor shaft (9) and / or the rotor (2) and / or that c. the coupling element (7) is arranged coaxially to the rotor shaft (9). [10] Motor vehicle transmission (13) according to claim 8 or 9, characterized by that the brake (6) has another coupling element (8) which a. is connected to a housing in a rotationally fixed manner and / or the b. is connected to the coupling element (7) in a rotationally fixed manner when the brake (6) is closed. [11] Motor vehicle transmission (13) according to one of claims 8 to 10, characterized by a return element (12) which is operatively connected to the coupling element (7) and by means of which the coupling element (7) can be brought from the second position into the first position. [12] Motor vehicle transmission (13) according to one of claims 6 to 11, characterized by that an electronics (35) of the electrical machine (1) a control device (36) which causes the actuating means (11) to be energised and / or b. a communication means (37) for communicating with the control unit (38) of the motor vehicle transmission (13) and / or a motor vehicle electrical system (34).

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