Drive assembly, and method for operating a drive assembly

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, comprising an electric machine (16) having a stator (18) and a rotor (20) and comprising a first control device (21) for controlling a coolant flow through the stator (18) and / or the rotor (20), the first control device (21) being designed to control a coolant flow through the stator (18) and / or the rotor (20) on the basis of the operating state of the drive assembly (10), in particular on the basis of the operating state of the electric machine (16). In addition, the invention relates to a method for operating such a drive assembly (10).

Description

[0001] Description

[0002] title

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

[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, and to a method for operating a drive arrangement with features of the dependent claim.

[0006] Electric motors in vehicles, especially electrified axles (e-axles), generate heat during operation. To prevent overheating, this heat can be dissipated. This can be achieved by cooling the electric motor as part of a cooling circuit. A coolant can be circulated through the circuit by a pump and passed through the electric motor. Alternatively, temperature-resistant permanent magnets can be used, but these can lead to higher costs, a potential drop in performance, and undesirable driving characteristics.

[0007] CN115139771A discloses a cooling of the electric machine using a coolant.

[0008] The disadvantage is that such cooling is usually not efficient and cost-effective to implement.

[0009] Disclosure of the invention

[0010] According to the invention, a drive arrangement for a vehicle, in particular a motor vehicle, is proposed. The drive arrangement comprises a cooling circuit in which a coolant is circulated. The cooling circuit comprises an electric machine with a stator and a rotor. The cooling circuit includes a first control device for controlling the coolant flow through the stator and / or the rotor. The first control device is configured to control the coolant flow through the stator and / or the rotor depending on an operating state of the drive arrangement, in particular the electric machine.

[0011] 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. In particular, 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] The operating state can depend on the driving profile, route profile, load, and application of the drive system or vehicle. In particular, a spatial zone within a critical temperature range in the drive system, especially in the electric machine, can change depending on the operating state. For example, this zone might be located in the stator area during acceleration and in the rotor area during constant driving at 130 km / h.

[0014] Cooling can be implemented efficiently and cost-effectively by controlling the coolant flow, particularly through the rotor and / or stator, based on the operating conditions. Different components of the drive system, especially the electric motor, can be selectively controlled with the coolant as needed, thus ensuring optimal temperature control. This can lead to an increase in the performance of the drive system, particularly the electric motor.

[0015] 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.

[0016] The rotor can be arranged 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.

[0017] 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.

[0018] This allows for the most efficient possible cooling of the stator and / or the rotor.

[0019] According to a further development of the drive arrangement, the first control device can be located in the area of ​​the electric machine. The first control device can be located on or in the electric machine. The first control device can be integrated into the electric machine.

[0020] This enables the most efficient and rapid control of coolant flow through the electric machine or the stator and / or rotor.

[0021] 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 coupled to an external cooling circuit that transports the heat externally. The heat exchanger can be designed to be bypassable. In other words, the coolant can be directed either through the heat exchanger or around it (e.g., by means of a bypass).

[0022] This allows for efficient cooling of the coolant using simple means.

[0023] 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.

[0024] This allows the coolant to circulate within the circuit using simple means.

[0025] According to a further development of the drive arrangement, the cooling circuit can include a gearbox for transmitting torque within the drive arrangement. The gearbox and the electric machine can be connected in parallel or in series within the cooling circuit.

[0026] This allows the gearbox to be cooled using simple means.

[0027] According to a further development of the drive arrangement, the cooling circuit can include a second control device for controlling the coolant flow through the transmission. The second control device can be configured to control (or bypass) the coolant flow through the transmission depending on an operating state of the drive arrangement, in particular the electric machine.

[0028] Alternatively or additionally, the cooling circuit can include a third control device for controlling the coolant flow through the heat exchanger. This third control device can be configured to control (or bypass) the coolant flow through the heat exchanger depending on the operating state of the drive assembly, particularly the electric motor. This allows for further optimization of the cooling of the drive assembly, especially the electric motor.

[0029] According to a further development of the drive arrangement, the first, second and / or third control device can each comprise or be formed from at least one actuator, at least one valve, at least one proportional valve (solenoid), in particular an electro-hydraulic valve, at least one flow control valve, at least one spring-loaded ball seat valve, at least one control valve and / or at least one switching valve.

[0030] This allows the first, second and / or third control unit to be implemented using simple means.

[0031] The first, second, and / or third control unit can be configured as a single control unit. The first, second, and / or third control unit can also be configured as a component of the cooling circuit or the drive assembly.

[0032] According to the invention, a method for operating a drive arrangement as described above is proposed. The method comprises the following steps:

[0033] 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.

[0034] 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 operating state of the drive assembly, in particular the electric machine. This can be implemented using the first, second, and / or third control unit.

[0035] 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.

[0036] According to a further development of the procedure, the procedure can include the following step:

[0037] 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.

[0038] This can be implemented by means of pulse width modeling of a control signal from the first, second, and / or third 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.

[0039] This allows for further optimization of the cooling of the drive assembly, especially the electric machine.

[0040] Embodiments of the invention are explained below with reference to the accompanying drawings. These show:

[0041] Figure 1 shows a schematic representation of a drive arrangement according to a first embodiment;

[0042] Figure 2 shows a schematic sectional view of an electric machine of the drive arrangement according to Figure 1;

[0043] Figure 3 shows a schematic representation of the drive arrangement according to a second embodiment;

[0044] Figure 4 shows a schematic representation of the drive arrangement according to a third embodiment;

[0045] Figure 5 shows a schematic representation of the drive arrangement according to a fourth embodiment and Figure 6 shows a schematic representation of the drive arrangement according to a fifth embodiment.

[0046] 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.

[0047] The cooling circuit 12 comprises an electric machine 16 with a stator 18 and a rotor 20. The cooling circuit 12 includes a first control device 21 for controlling a coolant flow through the stator 18 and / or the rotor 20. The first control device 21 is configured to control the coolant flow through the stator 18 and / or the rotor 20 depending on an operating state of the drive arrangement 10, in particular the electric machine 16.

[0048] The first control device 21 can be arranged in the area of ​​the electric machine 16, in particular on or in the electric machine 16. The first control device 21 can be implemented in the electric machine 16, in particular in a module of the electric machine 16.

[0049] The cooling circuit 12 can include a heat exchanger 46 for heat removal. The heat exchanger 46 can be coupled to an external cooling circuit 48. The heat can be removed externally, i.e., from the cooling circuit 12 of the drive assembly 10, by means of the external cooling circuit 48.

[0050] 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.

[0051] The cooling circuit 12 can include a gearbox 56 for transmitting torque within the drive arrangement 10. The gearbox 56 and the electric machine 16 can be connected in parallel or in series within the cooling circuit 12. In this case, the gearbox 56 and the electric machine 16 are connected in parallel within the cooling circuit 12.

[0052] The flow of the coolant 14 in the cooling circuit 12 is as follows:

[0053] 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, the coolant pump 54, and the heat exchanger 46. After the heat exchanger 46, the coolant 14 flows firstly through the gearbox 56 and then back into the coolant sump 50. Secondly, after the heat exchanger 46, the coolant 14 flows through the first control unit 21, the electric machine 16 (or the stator 18 and / or the rotor 20), and then back into the coolant sump 50.

[0054] In this case, the first control device 21 divides the coolant 14 into four coolant paths, each of which runs through different areas of the stator 18 or the rotor 20.

[0055] Figure 2 shows a schematic sectional view of the electric machine 16 of the drive arrangement 10 according to Figure 1.

[0056] 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.

[0057] 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.

[0058] 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. 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.

[0059] 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.The first control device 21 can be configured to control the coolant flow through the first, second, third and / or fourth fluid channel 38, 40, 42, 44 depending on an operating state of the drive arrangement 10, in particular the electric machine 16.

[0060] The first control device 21 can comprise or be formed from at least one actuator, at least one valve, at least one proportional valve (solenoid), in particular an electro-hydraulic valve, at least one flow control valve, at least one spring-loaded ball seat valve, at least one control valve and / or at least one switching valve.

[0061] Figure 3 shows a schematic representation of the drive arrangement 10 according to a second embodiment. The second embodiment differs from the first embodiment in the following ways:

[0062] The cooling circuit 12 comprises a second control device 31 for controlling the coolant flow through the transmission 56. The second control device 31 can be configured to control the coolant flow through the transmission 56 depending on an operating state of the drive arrangement 10, in particular the electric machine 16. The second control device 31 can comprise or be formed from at least one actuator, at least one valve, at least one proportional valve (solenoid), in particular an electro-hydraulic one, at least one flow control valve, at least one spring-loaded ball seat valve, at least one control valve, and / or at least one switching valve.

[0063] In particular, the coolant flow, e.g. by means of a volume flow valve, through the gearbox 56 and thus the distribution of the coolant 14 between the gearbox 56 and the electric machine 16 (or the stator 18 and / or the rotor 20) can be regulated. For example, a volume flow (or

[0064] The flow rate) of the coolant 14 through the electric machine 16 (or the stator 18 and / or the rotor 20) can be influenced while the coolant pump 54 maintains a constant power output.

[0065] Figure 4 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:

[0066] The gearbox 56 and the electric machine 16 are connected in series. In this case, the gearbox 56 is connected downstream of the electric machine 16, i.e., in the direction of coolant flow 14, it is located after the electric machine 16.

[0067] This allows cooling channels or lines of the cooling circuit 12 to be saved and the drive arrangement 10 to be designed more cost-effectively overall, especially with the same performance.

[0068] Figure 5 shows a schematic representation of the drive arrangement 10 according to a fourth embodiment. The fourth embodiment differs from the first embodiment in the following ways:

[0069] The first control device 21 comprises four valves. Each valve is configured to open and / or close one of the four fluid channels 38, 40, 42, 44 via the electric machine 16 (or the stator 18 and / or the rotor 20). The valves are designed as spring-loaded ball seat valves 58. These valves can open or close the respective fluid channel 38, 40, 42, 44 based on different spring characteristics, particularly depending on the coolant pressure 14 and / or the settings of the coolant pump 54. The cost-effectiveness of the spring-loaded ball seat valves 58 reduces the overall cost of the drive assembly 10.

[0070] Figure 6 shows a schematic representation of the drive arrangement 10 according to a fifth embodiment. The fifth embodiment differs from the second embodiment in the following ways:

[0071] The cooling circuit 12 includes a third control device 41 for controlling the coolant flow through the heat exchanger 46. The heat exchanger 46 has a bypass line 49 for bypassing the heat exchanger 46. The third control device 41 is configured to control (or bypass) the coolant flow through the heat exchanger 46 depending on the operating state of the drive arrangement 10, in particular the electric machine 16.

[0072] The third control device 41 can comprise or be formed from at least one actuator, at least one valve, at least one proportional valve (solenoid), in particular an electro-hydraulic valve, at least one flow control valve, at least one spring-loaded ball seat valve, at least one control valve and / or at least one switching valve.

[0073] In this arrangement, the coolant 14 is directed into the stator 18 via a first coolant path and into the rotor 20 via a second coolant path. The first control device 21 comprises a switching valve 60, which is arranged in the second coolant path and regulates the coolant flow through the second coolant path.

[0074] In this case, the second and third control units 31 and 41 for controlling the coolant flow through the heat exchanger 46 and through the transmission 56, respectively, each comprise a switching valve 60 (or are each formed from a switching valve 60). Due to the cost-effective switching valves 60, the costs of the entire drive assembly 10 can be reduced. By setting an on / off time of the switching valves 60, the coolant flow rate 14 can be adjusted based on pulse width.

[0075] The following describes a method for operating a drive arrangement 10 according to the above descriptions, with reference to Figures 1 to 6. The drive arrangement 10 can be one of the drive arrangements 10 shown in Figures 1 to 6. The method comprises the following steps:

[0076] 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 56. This can be implemented by means of the coolant pump 54.

[0077] 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 an operating state of the drive arrangement 10, in particular the electric machine 16. This can be implemented by means of the first, second and / or third control device 21, 31, 41.

[0078] The procedure may include the following steps:

[0079] 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.

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 first control device (21) for controlling a coolant flow through the stator (18) and / or the rotor (20), wherein the first control device (21) is configured to control a coolant flow through the stator (18) and / or the rotor (20) depending on an operating state of the drive arrangement (10), in particular the electric machine (16).

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 directs the coolant (14) from the first and second ends (24, 26) of the stator (18), has at least a third fluid channel (42) which extends at least partially through the housing (22) and carries the coolant, (14) to the first and second ends (32, 34) of the rotor (20), has at least a 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 first control device (21) is arranged in the area of ​​the electric machine (16), in particular on or in the electric machine (16).

4. Drive arrangement (10) according to one of the preceding claims, 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 coupled to an external cooling circuit (48).

5. 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).

6. Drive arrangement (10) according to one of the preceding claims, characterized in that the cooling circuit (12) comprises a transmission (56) for transmitting a torque within the drive arrangement (10), wherein the transmission (56) and the electric machine (16) are connected in parallel or in series in the cooling circuit (12).

7. Drive arrangement (10) according to one of the preceding claims and at least claim 4 and / or 6, characterized in that the cooling circuit (12) comprises a second control device (31) for controlling a coolant flow through the transmission (56) and / or a third control device (41) for controlling a coolant flow through the heat exchanger (46), wherein the second control device (31) and / or the third control device (41) are configured to control the respective coolant flow depending on an operating state of the to control the drive arrangement (10), in particular the electric machine (16).

8. Drive arrangement (10) according to one of the preceding claims, characterized in that the first, the second and / or the third control device (21 , 31 , 41) each comprises or is formed from at least one actuator, at least one valve, at least one proportional valve, in particular an electro-hydraulic valve, at least one flow control valve, at least one spring-loaded ball seat valve (58), at least one control valve and / or at least one switching valve (60).

9. 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 (56); 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 an operating state of the drive arrangement (10), in particular the electric machine (16).

10. Method according to claim 9, 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).

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