Drive assembly, method for operating a drive assembly, and vehicle

Abstract

The invention relates to a drive assembly (10) for a vehicle, in particular a motor vehicle, having a cooling circuit (12) in which a coolant (14) is conveyed. The drive assembly comprises an electric machine (16) having a stator (18) and a rotor (20), a transmission (19), and a control device (21) for controlling a coolant flow through the stator (18), the rotor (20), and / or the transmission (19), the control device (21) being designed to control a coolant flow through the stator (18), the rotor (20), and / or the transmission (19) on the basis of a heat loss occurring in the stator (18), the rotor (20), and / or the transmission (19). The invention likewise relates to a method for operating such a drive assembly (10) and to a vehicle comprising such a drive assembly (10).

Description

[0001] Description

[0002] title

[0003] Drive arrangement, method for operating a drive arrangement and a vehicle

[0004] State of the art

[0005] The invention relates to a drive arrangement for a vehicle, in particular a motor vehicle, with features of claim 1, a method for operating a drive arrangement with features of claim 8, and a vehicle, in particular a motor vehicle, with features of claim 11.

[0006] In a drive system with an electric motor, particularly in electrified axles (e-axles), heat is generated during operation. To operate the drive system as efficiently as possible, temperature management is therefore necessary. A cooling circuit with a coolant circulated within the circuit by a pump can be used for this purpose. The heat absorbed by the coolant can then be used to preheat components of the drive system.

[0007] US 2018 / 0083509 A1 discloses a method of generating waste heat in the stator, whereby this waste heat is used to warm up a vehicle battery.

[0008] The disadvantage is that efficient and cost-effective temperature management of the drive assembly is not possible.

[0009] Disclosure of the invention

[0010] According to the invention, a drive arrangement for a vehicle, in particular a motor vehicle, is proposed, comprising a cooling circuit in which a coolant is circulated. The cooling circuit includes an electric machine with a stator and a rotor. The cooling circuit includes a transmission for transmitting torque within the drive arrangement. The cooling circuit includes a control device for controlling the coolant flow through the stator, the rotor, and / or the transmission. The control device is configured to control the coolant flow through the stator, the rotor, and / or the transmission depending on the heat loss generated in the stator, the rotor, and / or the transmission. In particular, the heat loss generated in or on the stator, rotor, and / or transmission can be absorbed and dissipated by means of the coolant. The coolant can, in particular, be temperature-controlled by means of the heat loss.The control unit can be configured to direct the coolant flow through at least one component of the drive assembly with the greatest heat loss. This component can be the stator, the rotor, and / or the gearbox.

[0011] The coolant can be a liquid, especially water and / or oil. The coolant can also act as a lubricant and have a lubricating effect. In other words, the coolant can be used for cooling and / or lubrication. Specifically, the coolant can also be a lubricant. The coolant or lubricant can be in liquid form, especially oil.

[0012] The drive arrangement can, for example, be designed as an e-axle or form part of an e-axle.

[0013] This allows the waste heat, which depends in particular on the application of the drive system, its operating state, a driving profile, and / or the ambient temperature, to be used to heat or preheat the coolant. This allows the coolant and the corresponding components of the drive system, which are heated by the coolant, or the drive system as a whole, to be brought up to operating temperature quickly.

[0014] For example, at cold ambient temperatures (<0°C), the coolant can be viscous. This can lead to losses due to high energy consumption (e.g., from high pump output or flow rate), generally increased transmission losses, and reduced cooling capacity due to limited flow rate. These losses can be avoided or at least reduced by (rapidly) preheating the coolant. This allows for range optimization of the drive system or a vehicle with such a drive system.

[0015] Heat, particularly waste heat, can be generated at various components of the drive system, such as the stator, rotor, and / or gearbox, depending on the operating cycle of the drive system or a vehicle with such a drive system. For example, most of the heat, or waste heat, is generated in the stator during start-up and at low speeds. At higher, especially constant, speeds, such as while driving on the highway, most of the heat is generated in the rotor. When the vehicle is stationary, the cooling of both the gearbox and the rotor can be completely switched off, or the rotor and gearbox can be bypassed. By switching off or bypassing the gearbox or rotor, the thermal mass can be significantly reduced.

[0016] The heat, especially waste heat, can be dissipated by means of appropriate control through an increased supply of coolant to the relevant component. This cools the component (stator, rotor and / or gearbox) and simultaneously heats the coolant (to operating temperature).

[0017] According to a further development of the drive arrangement, the electric machine can include a housing. The stator and / or the rotor can be arranged at least partially inside the housing. The stator can have a first end, a second end, and a central section arranged between the first and second ends.

[0018] The rotor can be mounted on a shaft and have a first end, a second end, and a central section located between the first and second ends. The electric machine can have at least one first, at least one second, at least one third, and at least one fourth fluid channel. The first fluid channel can extend at least partially through the housing and direct the coolant to the first and second ends of the stator. The second fluid channel can extend at least partially through the central section of the stator and direct the coolant from the first and second ends of the stator. The third fluid channel can extend at least partially through the housing and direct the coolant to the first and second ends of the rotor. The fourth fluid channel can extend at least partially through the central section of the rotor and / or the shaft and direct the coolant from the first and second ends of the rotor.

[0019] This allows the efficiency of the cooling circuit and thus the drive arrangement to be further optimized.

[0020] According to a further development of the drive arrangement, the cooling circuit can include a heat exchanger for removing heat (from the cooling circuit). The heat exchanger can be thermally coupled to an external cooling circuit. The external cooling circuit can be configured to transport the heat externally.

[0021] This allows the efficiency of the cooling circuit and thus the drive arrangement to be further optimized.

[0022] According to a further development of the drive arrangement, the heat exchanger can be designed to be bypassed by means of a bypass line. The control unit can be configured to control the coolant flow through the heat exchanger depending on the heat loss generated in the stator, rotor, and / or gearbox. The coolant can be routed either through the heat exchanger or around it (via the bypass line).

[0023] This allows the efficiency of the cooling circuit and thus the drive arrangement to be further optimized.

[0024] According to a further development of the drive arrangement, the drive arrangement can include an accumulator (battery or vehicle battery). The drive arrangement can be configured such that waste heat absorbed by the coolant in the cooling circuit is used to heat (preheat or pre-condition) the accumulator. The accumulator can be thermally coupled to the heat exchanger. The accumulator can also be thermally coupled to the external cooling circuit.

[0025] This allows the accumulator to be brought up to operating temperature quickly using simple means.

[0026] According to a further development of the drive arrangement, the cooling circuit can include a coolant sump for storing the coolant, a filter for filtering the coolant, and a coolant pump for circulating the coolant within the cooling circuit.

[0027] This allows the coolant to circulate within the circuit using simple means.

[0028] According to a further development of the drive arrangement, the control device can comprise or be formed from at least one valve, in particular several valves. The valve can be designed as a thermostatic valve, an electrohydraulic valve, a switching valve and / or a control valve.

[0029] This allows the control device to be implemented using simple means.

[0030] According to the invention, a method for operating a drive arrangement as described above is proposed. The method comprises the following steps:

[0031] Pumping the coolant through the stator, rotor, first fluid channel, second fluid channel, third fluid channel, fourth fluid channel, heat exchanger and / or gearbox. This can be achieved using the coolant pump.

[0032] Controlling the coolant flow through the stator, rotor, first fluid channel, second fluid channel, third fluid channel, fourth fluid channel, heat exchanger and / or gearbox depending on the heat loss generated in the stator, rotor and / or gearbox. This can be implemented using the control unit.

[0033] Regarding the advantages achievable with this method, reference is made to the relevant explanations concerning the drive arrangement. The measures described in connection with the drive arrangement and / or those explained below can be used to further develop the method.

[0034] According to a further development of the procedure, the procedure can include the following step:

[0035] Pulse width modeled control of the coolant flow through the stator, the rotor, the first fluid channel, the second fluid channel, the third fluid channel, the fourth fluid channel, the heat exchanger and / or the gearbox.

[0036] This can be implemented using pulse width modeling of a control signal from the control unit. In particular, a type of proportional function can be implemented, and a pulse-width-based coolant flow (or flow rate) can be set via the switch-on and switch-off times.

[0037] This allows the efficiency of the cooling circuit and thus the drive arrangement to be further optimized.

[0038] According to a further development of the procedure, the procedure can include the following step:

[0039] Deliberate generation of waste heat from the stator through inefficient stator control. In particular, the rotor is not rotated and / or heated when the stator is inefficiently controlled.

[0040] This can be implemented in particular when the drive system or a vehicle comprising the drive system is stationary.

[0041] This allows for the targeted and rapid generation of waste heat using simple means, warming the coolant to operating temperature. A high electrical power loss can be generated at the stator winding heads as well as within the stator itself, manifesting as heat. This waste heat can be used to preheat or pre-condition the coolant or the drive assembly. Since no torque is generated (vehicle stationary), rotation and thus heating of the rotor can be prevented.

[0042] According to the invention, a vehicle, in particular a motor vehicle, with a drive arrangement as described above is proposed. The vehicle comprises a vehicle interior. The vehicle is designed such that waste heat absorbed by the cooling circuit from the rotor, the stator, and / or the transmission is used to heat the vehicle interior. The vehicle interior can be thermally coupled to the heat exchanger. The vehicle interior can also be thermally coupled to the external cooling circuit.

[0043] Regarding the advantages achievable with the vehicle, reference is made to the relevant explanations concerning the drive system. The measures described in connection with the drive system and / or those explained below can be used for further vehicle development. The vehicle interior can thus be heated using simple means by means of waste heat (which would be generated anyway).

[0044] Embodiments of the invention are explained below with reference to the accompanying drawings. These show:

[0045] Figure 1 shows a schematic representation of a drive arrangement according to a first embodiment;

[0046] Figure 2 shows a schematic representation of the drive arrangement according to a second embodiment;

[0047] Figure 3 is a schematic representation of the drive arrangement according to a third embodiment; Figure 4 is a schematic sectional view of an electric machine of the drive arrangement according to Figure 3;

[0048] Figure 5 shows a schematic representation of the drive arrangement according to a fourth embodiment.

[0049] The drive assembly is designated by reference numeral 10 in Figure 1. The drive assembly 10 is designed for a vehicle, in particular a motor vehicle. The drive assembly 10 comprises a cooling circuit 12 in which a coolant 14 is circulated.

[0050] The cooling circuit 12 comprises an electric machine 16 with a stator 18 and a rotor 20. The cooling circuit 12 includes a gearbox 19 for transmitting torque within the drive arrangement 10. The cooling circuit 12 includes a control device 21 for controlling the coolant flow through the stator 18, the rotor 20, and / or the gearbox 19. The control device 21 is configured to control the coolant flow through the stator 18, the rotor 20, and / or the gearbox 19 depending on the heat loss generated in the stator 18, the rotor 20, and / or the gearbox 19.

[0051] The gearbox 19 and the electric machine 16 can be connected in parallel or in series in the cooling circuit 12.

[0052] The control device 21 can comprise or be formed from at least one valve 56. The valve 56 can be configured as a thermostatic valve, an electrohydraulic valve, a switching valve, and / or a control valve. The control device 21, or its valve(s) 56, can be arranged in the immediate vicinity of the respective components of the drive arrangement 10 to be switched by means of the valves 56. The control device 21, or its valve(s) 56, can be integrated into or arranged on a hydraulic module.

[0053] The cooling circuit 12 can include a heat exchanger 46 for heat removal. The heat exchanger 46 can be thermally coupled to an external cooling circuit 48. The external cooling circuit 48 can be configured to remove the heat externally, i.e., from the cooling circuit 12 of the drive assembly 10.

[0054] The heat exchanger 46 can be designed to be bypassed by means of a bypass line 49. The control device 21 can be configured to control the coolant flow through the heat exchanger 46 depending on the heat loss generated in the stator 18, the rotor 20 and / or the gearbox 19.

[0055] The control device 21 comprises two valves 56. A first valve 57 controls the coolant flow through the heat exchanger 46, and a second valve 58 controls the coolant flow through the gearbox 19. This control is based on the amount of heat loss generated in the stator 18, the rotor 20, and / or the gearbox 19.

[0056] The cooling circuit 12 can include a coolant sump 50 for storing the coolant 14, a filter 52 for filtering the coolant 14, and a coolant pump 54 for circulating the coolant 14 within the cooling circuit 12.

[0057] The flow of the coolant 14 in the cooling circuit 12 is as follows:

[0058] The coolant 14 is stored in the coolant sump 50. The coolant 14 is pumped by the coolant pump 54. The coolant 14 is routed from the coolant sump 50 through the filter 52 and the coolant pump 54. The coolant 14 is selectively routed by the control unit 21 either through the heat exchanger 46 or through the bypass line 49 around the heat exchanger 46. After the heat exchanger 46, the coolant 14 either passes through the gearbox 19 and then back into the coolant sump 50, or it passes through the electric machine 16 (or the stator 18 and / or the rotor 20) and then back into the coolant sump 50.

[0059] The drive assembly 10 can include an accumulator (not shown). The drive assembly 10 can be configured such that the waste heat absorbed in the cooling circuit 12 by means of the coolant 14 is used to heat the accumulator. The accumulator can be thermally coupled to the heat exchanger 46, in particular to the external cooling circuit 48.

[0060] Figure 2 shows a schematic representation of the drive arrangement according to a second embodiment. The second embodiment differs from the first embodiment in the following ways:

[0061] The control device 21 comprises three valves 56. A first valve 57 controls the coolant flow through the heat exchanger 46, a second valve 58 controls the coolant flow through the rotor 20, and a third valve 59 controls the coolant flow through the gearbox 19. This control is based on the amount of heat loss generated in the stator 18, the rotor 20, and / or the gearbox 19.

[0062] Figure 3 shows a schematic representation of the drive arrangement 10 according to a third embodiment. The third embodiment differs from the first embodiment in the following ways:

[0063] The control device 21 comprises two valves 56. A first valve 57 controls the flow of coolant through the heat exchanger 46, and a second valve 58 controls the flow of coolant through the stator 18 and / or the rotor 20 of the electric machine 16. This control is based on the amount of heat loss generated in the stator 18, the rotor 20, and / or the gearbox 19.

[0064] In this case, the bypass line 49 leads into the second valve 58. The second valve 58 divides the coolant 15 into four coolant paths, each of which runs through different areas of the stator 18 or the rotor 20.

[0065] Figure 4 shows a schematic sectional view of the electric machine 16 of the drive arrangement 10 according to Figure 3. The electric machine 16 can comprise a housing 22. The stator 18 and the rotor 20 can be arranged at least partially inside the housing 22.

[0066] The stator 18 can have a first end 24, a second end 26 and a first central section 28 arranged between the first and the second end 24, 26.

[0067] The rotor 20 can be arranged on a shaft 30. The rotor 20 can have a first end 32, a second end 34 and a central section 36 arranged between the first and second ends 32, 34.

[0068] The electric machine 16 can have at least one first fluid channel 38, at least one second fluid channel 40, at least one third fluid channel 42 and at least one fourth fluid channel 44.

[0069] The first fluid channel 38 can extend at least partially through the housing 22 and direct the coolant 14 to the first and second ends 24, 26 of the stator 18. The second fluid channel 40 can extend at least partially through the central section 28 of the stator 18 and direct the coolant 14 from the first and second ends 24, 26 of the stator 18. The third fluid channel 42 can extend at least partially through the housing 22 and direct the coolant 14 to the first and second ends 32, 34 of the rotor 20. The fourth fluid channel 44 can extend at least partially through the central section 36 of the rotor 20 and / or the shaft 30 and direct the coolant 14 from the first and second ends 32, 34 of the rotor 20.

[0070] The control device 21 can be configured to control the coolant flow through the first, second, third and / or fourth fluid channels 38, 40, 42, 44 depending on the heat loss generated in the stator 18, rotor 20 and / or gearbox 19.

[0071] Figure 5 shows a schematic representation of the drive arrangement 10 according to a fourth embodiment. The fourth embodiment differs from the third embodiment in the following way: In this case, the control device 21 comprises, in addition to the first valve 57 and the second valve 58, a third valve 59. By means of the third valve 59, the coolant flow through the gearbox 19 can be controlled depending on the heat loss generated in the stator 18, the rotor 20, and / or the gearbox 19. Furthermore, the bypass line 49 does not open into the second valve 58, but instead merges with the line that runs through the heat exchanger 46 after the heat exchanger 46.

[0072] The following describes a method for operating a drive arrangement 10 according to the above descriptions, with reference to Figures 1 to 5. The drive arrangement 10 can be one of those shown in Figures 1 to 5. The method comprises the following steps:

[0073] Pumping the coolant 14 through the stator 18, the rotor 20, the first fluid channel 38, the second fluid channel 40, the third fluid channel 42, the fourth fluid channel 44, the heat exchanger 46 and / or the gearbox 19. This can be implemented by means of the coolant pump 54.

[0074] Control of the coolant flow through the stator 18, the rotor 20, the first fluid channel 38, the second fluid channel 40, the third fluid channel 42, the fourth fluid channel 44, the heat exchanger 46 and / or the gearbox 19 depending on the heat loss generated in the stator 18, the rotor 20 and / or the gearbox 19. This can be implemented by means of the control unit 21.

[0075] The procedure may include the following steps:

[0076] Pulse width modeled control of the coolant flow through the stator 18, the rotor 20, the first fluid channel 38, the second fluid channel 40, the third fluid channel 42, the fourth fluid channel 44, the heat exchanger 46 and / or the gearbox 19.

[0077] The procedure may include the following steps:

[0078] Deliberate generation of waste heat from the stator 18 through inefficient control of the stator 18. In the case of inefficient control of the stator 18, the rotor 20 is specifically not rotated and / or heated. The following describes a vehicle, in particular a motor vehicle, with a drive arrangement 10 as described above. The drive arrangement 10 may be one of those shown in Figures 1 to 5.

[0079] The vehicle has a passenger compartment. The vehicle is designed such that the waste heat absorbed by the cooling circuit 12 (or the coolant 14) from the rotor 18, the stator 20 and / or the gearbox 19 is used to heat the passenger compartment.

[0080] The vehicle interior can be thermally coupled to the heat exchanger 46. The vehicle interior can be thermally coupled to the external cooling circuit 48.

Claims

Claims 1. Drive arrangement (10) for a vehicle, in particular a motor vehicle, with a cooling circuit (12) in which a coolant (14) is conveyed, comprising: an electric machine (16) with a stator (18) and a rotor (20), a gearbox (19) for transmitting a torque within the drive arrangement (10), a control device (21) for controlling a coolant flow through the stator (18), the rotor (20) and / or the gearbox (19), wherein the control device (21) is configured to control a coolant flow through the stator (18), the rotor (20) and / or the gearbox (19) depending on a loss of heat generated in the stator (18), in the rotor (20) and / or in the gearbox (19).

2. Drive arrangement (10) according to claim 1, characterized in that the electric machine (16) comprises a housing (22), wherein the stator (18) and the rotor (20) are arranged at least partially within the housing (22), wherein the stator (18) has a first end (24), a second end (26) and a central section (28) arranged between the first and the second end (24, 26), wherein the rotor (20) is arranged on a shaft (30) and has a first end (32), a second end (34) and a central section (36) arranged between the first and the second end (32, 34), wherein the electric machine (16) has at least one first fluid channel (38) which extends at least partially through the housing (22) and directs the coolant (14) to the first and second ends (24, 26) of the stator (18), and has at least one second fluid channel (40).which extends at least partially through the central section (28) of the stator (18) and the coolant (14) from the first and second ends (24, 26) of the, stator (18), has at least one third fluid channel (42) which extends at least partially through the housing (22) and directs the coolant (14) to the first and second ends (32, 34) of the rotor (20), has at least one fourth fluid channel (44) which extends at least partially through the central section (36) of the rotor (20) and / or the shaft (30) and directs the coolant (14) from the first and second ends (32, 34) of the rotor (20).

3. Drive arrangement (10) according to claim 1 or 2, characterized in that the cooling circuit (12) comprises a heat exchanger (46) for the removal of heat, in particular wherein the heat exchanger (46) is thermally coupled to an external cooling circuit (48).

4. Drive arrangement (10) according to claim 3, characterized in that the heat exchanger (46) is designed to be bypassable by means of a bypass line (49), wherein the control device (21) is set up to control a coolant flow via the heat exchanger (46) depending on a loss heat generated in the stator (18), in the rotor (20) and / or in the gearbox (19).

5. Drive arrangement (10) according to one of the preceding claims, characterized in that the drive arrangement (10) comprises an accumulator, wherein the drive arrangement (10) is configured such that the waste heat absorbed in the cooling circuit (12) by means of the coolant (14) is used to heat the accumulator, in particular wherein the accumulator is thermally coupled to the heat exchanger (46), in particular to the external cooling circuit (48).

6. Drive arrangement (10) according to one of the preceding claims, characterized in that the cooling circuit (12) comprises a coolant sump (50) for storing the coolant (14), a filter (52) for filtering the coolant (14) and a coolant pump (54) for pumping the coolant (14) within the cooling circuit (12).

7. Drive arrangement (10) according to one of the preceding claims, characterized in that the control device (21) has at least one Valve (56, 57, 58, 59), in particular a thermostatic valve, an electrohydraulic valve, a switching valve and / or a control valve, comprises or is formed from.

8. Method for operating a drive arrangement (10) according to one of the preceding claims, characterized by the steps: Conveying the coolant (14) through the stator (18), the rotor (20), the first fluid channel (38), the second fluid channel (40), the third fluid channel (42), the fourth fluid channel (44), the heat exchanger (46) and / or the gearbox (19); Control of the coolant flow through the stator (18), the rotor (20), the first fluid channel (38), the second fluid channel (40), the third fluid channel (42), the fourth fluid channel (44), the heat exchanger (46) and / or the gearbox (56) depending on the heat loss generated in the stator (18), in the rotor (20) and / or in the gearbox (19).

9. Method according to claim 8, characterized by the step: Pulse width modeled control of the coolant flow through the stator (18), the rotor (20), the first fluid channel (38), the second fluid channel (40), the third fluid channel (42), the fourth fluid channel (44), the heat exchanger (46) and / or the gearbox (56).

10. Method according to claim 8 or 9, characterized by the step: Targeted generation of waste heat from the stator (18) by inefficiently controlling the stator (18), in particular wherein the rotor (20) is not rotated and / or heated when the stator (18) is inefficiently controlled.

11. Vehicle, in particular motor vehicle, comprising a drive arrangement (10) according to one of claims 1 to 7 and a vehicle interior, wherein the vehicle is arranged such that the waste heat absorbed by means of the cooling circuit (12) is used by the stator (18), the rotor (20) and / or the transmission (19) to heat the vehicle interior.

Images