Drive arrangement, vehicle having a drive arrangement, and method for operating a drive arrangement

Abstract

The invention relates to a drive arrangement (10) having features of claim (1), to a vehicle (14) comprising a drive arrangement (10) of said kind, and to a method for operating a drive arrangement (10) of said kind.

Description

[0001] R.413680

[0002] Description

[0003] title

[0004] Drive arrangement, vehicle with a drive arrangement and a method for operating a drive arrangement

[0005] State of the art

[0006] The invention relates to a drive arrangement with features of claim 1, a vehicle with such a drive arrangement and a method for operating such a drive arrangement.

[0007] In drive systems with an electric motor, heat is generated during operation. To prevent overheating of the drive system, and especially the electric motor, this heat can be dissipated. A cooling circuit can be provided for this purpose, in which a coolant is circulated through the electric motor by a pump. A bypassable heat exchanger can be used for more efficient heat dissipation. The coolant can be used for cooling and lubricating components. To ensure the correct operation of the components supplied with the coolant, the coolant pressure within the cooling circuit can be measured and monitored using a pressure sensor.

[0008] The disadvantage is that pressure sensors are expensive and increase the overall cost of the drive system or cooling circuit.

[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 first coolant is or can be conveyed. R.413680

[0011] - 2 -

[0012] The cooling circuit includes a coolant reservoir for storing the coolant. The cooling circuit includes a coolant pump for circulating the coolant within the circuit. The cooling circuit includes a temperature sensor for determining the coolant temperature. The temperature sensor may be located downstream of the coolant pump (immediately) in the direction of coolant flow. The cooling circuit includes at least one component that is supplied with, or can be supplied with, the coolant. The drive assembly, in particular the cooling circuit, is configured to determine the coolant pressure within the cooling circuit using a predictive model.

[0013] This eliminates the need for a physical pressure sensor. A virtual pressure sensor can be implemented. The coolant pressure can be determined or predicted, thus dispensing with a physical pressure sensor. The coolant pressure can be calculated using the predictive model. This reduces the overall cost of the drive system and / or cooling circuit.

[0014] The prediction model can be based on known static and / or dynamic parameters of the drive arrangement, in particular the cooling circuit and / or the external cooling circuit.

[0015] According to a further development of the drive arrangement, the component that is or can be supplied with coolant can be designed as a heat exchanger, a bypass line, a first valve, at least one first coolant line, an electric machine with a stator and a rotor, a second valve, at least one second coolant line, a gearbox, a third valve, at least one third coolant line, a parking lock, a fourth valve and / or at least one fourth coolant line.

[0016] The heat exchanger can be thermally coupled to an external cooling circuit. The bypass line can be designed to bypass the heat exchanger. The parking lock can be designed to interrupt torque within the drive assembly. The parking lock can be configured to be actuated by the coolant. The parking lock can be designed as a hydraulic parking lock. The coolant can be used as a hydraulic fluid for the parking lock. R.413680

[0017] - 3 -

[0018] The first valve can be configured to direct the coolant through the heat exchanger and / or the bypass line. The second valve can be a proportional valve. The second valve can be configured to direct the coolant through the electric motor, stator, and / or rotor. The third valve can be configured to direct the coolant through the gearbox. The fourth valve can be configured to direct the coolant to the parking brake.

[0019] The first coolant line can be configured for the fluidic coupling of the heat exchanger, the bypass line, and / or the first valve. The second coolant line can be configured for the fluidic coupling of the electric motor, the stator, the rotor, and / or the second valve. The third coolant line can be configured for the fluidic coupling of the gearbox and / or the third valve. The fourth coolant line can be configured for the fluidic coupling of the parking lock and / or the fourth valve.

[0020] This allows the efficiency of the cooling circuit and thus the drive arrangement to be further optimized.

[0021] In this context, a fluidic connection or fluidic coupling means that a fluid can flow between two fluidically coupled elements or between two elements that are in fluidic connection.

[0022] The coolant can also function as a lubricant. In other words, the coolant can be used for cooling and / or lubrication. The coolant can be in liquid form, particularly oil. The coolant can also be used as a hydraulic fluid to actuate or operate the parking lock.

[0023] According to a further development of the drive arrangement, the predictive model can be based on the coolant flow rate and the hydraulic resistance of the cooling circuit. The pressure to be determined using the predictive model can be calculated by multiplying the flow rate of the R.413680

[0024] - 4 -

[0025] The coolant and the hydraulic resistance of the cooling circuit must be calculated.

[0026] This allows the pressure of the coolant within the cooling circuit to be determined or calculated using simple means.

[0027] According to a further development of the drive arrangement, the coolant flow rate can be calculated based on at least one parameter of the coolant pump, in particular the pump's delivery velocity. Alternatively or additionally, the coolant flow rate can be calculated based on at least one parameter of the coolant itself. This coolant parameter can be its temperature, heat capacity, and / or viscosity. The coolant temperature, in particular, can influence its viscosity.

[0028] This allows the coolant flow rate to be calculated using simple means.

[0029] According to a further development of the drive arrangement, the drive arrangement, in particular the cooling circuit, can comprise a first coolant path with a first hydraulic resistance, a second coolant path with a second hydraulic resistance, a third coolant path with a third hydraulic resistance and / or a fourth coolant path with a fourth hydraulic resistance.

[0030] The heat exchanger, bypass line, first valve, and / or first coolant line may be located within the first coolant path. The electric motor, stator, rotor, second valve, and / or second coolant line may be located within the second coolant path. The gearbox, third valve, and / or third coolant line may be located within the third coolant path. The parking lock, fourth valve, and / or fourth coolant line may be located within the fourth coolant path.

[0031] The hydraulic resistance of the cooling circuit can be determined based on the first hydraulic resistance, the second hydraulic resistance, the third R.413680

[0032] - 5 - hydraulic resistance, the fourth hydraulic resistance, a switching state of the first valve, a switching state of the second valve, a switching state of the third valve, a switching state of the fourth valve, a leakage of the second coolant path, a leakage of the third coolant path, a temperature of the coolant and / or at least one parameter of the coolant.

[0033] This allows the hydraulic resistance of the cooling circuit to be calculated using simple means.

[0034] According to a further development of the drive arrangement, the second coolant path, the third coolant path, and / or the fourth coolant path can be fluidically connected (arranged) in parallel. In other words, the second, third, and / or fourth coolant paths can be fluidically coupled in parallel.

[0035] This allows the second, third and / or fourth hydraulic resistance, and thus the hydraulic resistance of the cooling circuit, to be calculated using simple means.

[0036] According to a further development of the drive arrangement, the first and second coolant paths can be fluidically connected (arranged) in series. The first and third coolant paths can be fluidically connected (arranged) in series. The first and fourth coolant paths can be fluidically connected (arranged) in series. In other words, the first coolant path and the second, third, and / or fourth coolant paths can be fluidically coupled in series.

[0037] This allows the first, second, third and / or fourth hydraulic resistance, and thus the hydraulic resistance of the cooling circuit, to be calculated using simple means.

[0038] According to a further development of the drive arrangement, the first coolant path, the second coolant path, the third coolant path, the fourth coolant path, the cooling circuit and / or the drive arrangement can each be designed without a pressure sensor (i.e., without a physical pressure sensor). R.413680

[0039] - 6 -

[0040] This can reduce the costs of the respective coolant path, cooling circuit and / or drive arrangement.

[0041] The cooling circuit may include a filter for filtering the coolant. The drive assembly, in particular the cooling circuit, may comprise a module. The module may be designed as a flexible thermal unit (FTU). The filter, coolant reservoir, coolant pump, temperature sensor, heat exchanger, bypass line, first valve, (at least partially) the first coolant line, second valve, (at least partially) the second coolant line, third valve, (at least partially) the third coolant line, fourth valve, and / or (at least partially) the fourth coolant line may be arranged within the module.

[0042] This allows the individual elements arranged within the module to be implemented in the drive arrangement or circuit in a space-saving and simple manner.

[0043] According to the invention, a vehicle, in particular a motor vehicle, with a drive arrangement as described above is proposed.

[0044] Regarding the advantages achievable with the vehicle, 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 for further vehicle development.

[0045] According to the invention, a method for operating a drive arrangement as described above is proposed. The method comprises the step:

[0046] Determining the coolant pressure within the cooling circuit using the predictive model. The pressure can be determined by calculation. R.413680

[0047] - 7 -

[0048] 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.

[0049] Embodiments of the invention are explained below with reference to the accompanying drawings. These show:

[0050] Figure 1 shows a schematic representation of a drive arrangement according to a first embodiment,

[0051] Figure 2 shows a schematic representation of the drive arrangement according to a second embodiment.

[0052] Figure 3 shows a schematic representation of a first coolant path of the drive arrangement according to Figure 2 and

[0053] Figure 4 shows a schematic representation of a second, a third and a fourth coolant path of the drive arrangement according to Figure 2.

[0054] 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 or can be conveyed.

[0055] The cooling circuit 12 comprises a coolant reservoir 16 for storing the coolant 14 and a coolant pump 18 for circulating the coolant 14 within the cooling circuit 12. The cooling circuit 12 includes a temperature sensor 20 for determining the temperature of the coolant 14 and at least one component 22 that is supplied or can be supplied with the coolant 14.

[0056] The drive arrangement 10, in particular the cooling circuit 12, is configured to maintain a pressure P of the coolant 14 within the cooling circuit 12 by means of R.413680

[0057] - 8 - of a prediction model. This allows a virtual pressure sensor 13 to be implemented. In other words, the pressure P of the coolant 14 within the cooling circuit 12 at the position where the virtual pressure sensor 13 is shown in Figure 1 can be determined or predicted (calculated). A physical pressure sensor is therefore unnecessary.

[0058] Figure 2 shows a schematic representation of the drive arrangement 10 according to a second embodiment. The second embodiment differs from the first embodiment shown in Figure 1 in the following ways:

[0059] The component 22 can be configured as a heat exchanger 24, a bypass line 26, a first valve 28, at least one first coolant line 30, an electric machine 32 with a stator 34 and a rotor 36, a second valve 38, at least one second coolant line 40, a gearbox 42, a third valve 44, at least one third coolant line 46, a parking lock 48, a fourth valve 50 and / or at least one fourth coolant line 52.

[0060] The heat exchanger 24 can be thermally coupled to an external cooling circuit 25. The bypass line 26 can be configured to bypass the heat exchanger 24. The parking lock 48 can be configured to interrupt torque within the drive assembly 10.

[0061] The first valve 28 can be configured to direct the coolant 14 through the heat exchanger 24 and / or the bypass line 26. The second valve 38 can be configured to direct the coolant 14 through the electric motor 32, the stator 34, and / or the rotor 36. The third valve 44 can be configured to direct the coolant 14 through the gearbox 42. The fourth valve 50 can be configured to direct the coolant 14 to the parking lock 48.

[0062] The first coolant line 30 can be configured for the fluidic coupling of the heat exchanger 24, the bypass line 26, and / or the first valve 28. The second coolant line 40 can be configured for the fluidic coupling of the electric machine 32, the stator 34, and / or the rotor 36. R.413680

[0063] - 9 - be configured. The third coolant line 46 can be configured for the fluidic coupling of the transmission 42 and / or the third valve 44. The fourth coolant line 52 can be configured for the fluidic coupling of the parking lock 48 and / or the fourth valve 50.

[0064] The cooling circuit 12 can include a filter 15 for filtering the coolant 14. The filter 15 can be arranged between the coolant pump 18 and the coolant reservoir 16.

[0065] The drive assembly 10, in particular the cooling circuit 12, can comprise a module 27. The module 27 can be designed as a flexible thermal unit. The filter 15, the coolant reservoir 16, the coolant pump 18, the temperature sensor 20, the heat exchanger 24, the bypass line 26, the first valve 28, at least partially the first coolant line 30, the second valve 38, at least partially the second coolant line 40, the third valve 44, at least partially the third coolant line 46, the fourth valve 50 and / or at least partially the fourth coolant line 52 can be arranged within the module 27.

[0066] The prediction model can be based on a flow rate Q of the coolant 14 and a hydraulic resistance R of the cooling circuit 12. The pressure P to be determined using the prediction model can be calculated by multiplying the flow rate Q of the coolant 14 and the hydraulic resistance R of the cooling circuit 12 (see below).

[0067] The flow rate Q of the coolant 14 can be calculated on the basis of at least one parameter of the coolant pump 18, in particular a delivery rate of the coolant pump 18, and / or at least one parameter of the coolant 14, in particular the temperature and / or the heat capacity of the coolant 14.

[0068] Figure 3 shows a schematic representation of a first coolant path 54 of the drive assembly 10 or the cooling circuit 12 according to Figure 2. The heat exchanger 24, the bypass line 26, the first valve 28 and / or the first coolant line 30 are arranged within the first coolant path 54. R.413680

[0069] - 10 -

[0070] Figure 3 above shows the first coolant path 54 when the coolant 14 is routed through the heat exchanger 24. For this purpose, the first valve 28 is switched in a corresponding "bypass line off" state (also shown in Figure 2).

[0071] Figure 3 below shows the first coolant path 54 when the coolant 14 is routed through the bypass line 26. For this purpose, the first valve 28 is switched in a corresponding "bypass line on" switching state.

[0072] The first coolant path 54 can have a first hydraulic resistance R1. The first coolant line 30 can have a hydraulic resistance 62. The first valve 28 can have a hydraulic resistance 64 in the "bypass line off" position. The first valve 28 can have a hydraulic resistance 66 in the "bypass line on" position. The heat exchanger 24 can have a hydraulic resistance 68. The bypass line 26 can have a hydraulic resistance 70. The first hydraulic resistance R1 can be calculated from the sum of the hydraulic resistances 62, 64, 66, 68, and 70 of the respective components:

[0073] R1 (when switching state "bypass line off") = 62 + 64 + 68 R1 (when switching state "bypass line on") = 62 + 66 + 70

[0074] Figure 4 shows a schematic representation of a second, a third and a fourth coolant path 56, 58, 60 of the drive arrangement 10 or of the cooling circuit 12 according to Figure 2.

[0075] The electric machine 32, the stator 34, the rotor 36, the second valve 38, and / or the second coolant line 40 can be arranged within the second coolant path 56. The second coolant path 56 can have a second hydraulic resistance R2. The second coolant line 40 can have a hydraulic resistance 72. The second valve 38 can have a hydraulic resistance 74. The second valve 38 can be configured as a proportional valve. The stator 34 can have a hydraulic resistance 76. The rotor 36 can have a hydraulic resistance 78. A leakage from the second coolant path 56 can cause an R.413680

[0076] - 11 - exhibit hydraulic resistance of 80. The second hydraulic resistance R2 can be calculated from the hydraulic resistances 72, 74, 76, 78, 80 of the respective components.

[0077] The transmission 42, the third valve 44, and / or the third coolant line 46 can be located within the third coolant path 58. The third coolant path 58 can have a third hydraulic resistance R3. The third coolant line 46 can have a hydraulic resistance 82. The third valve 44 can have a hydraulic resistance 84 in the "transmission on" switching state. The transmission 42 can have a hydraulic resistance 86. A leak in the third coolant path 58 can have a hydraulic resistance 88. The third hydraulic resistance R3 can be calculated from the hydraulic resistances 82, 84, 86, and 88 of the respective components.

[0078] The parking lock 48, the fourth valve 50, and / or the fourth coolant line 52 can be arranged within the fourth coolant path 60. The fourth coolant path 60 can have a fourth hydraulic resistance R4. The fourth coolant line 52 can have a hydraulic resistance 90. The fourth valve 50 can have a hydraulic resistance 92. The parking lock 48 can have a hydraulic resistance 94. The fourth hydraulic resistance R4 can be calculated from the hydraulic resistances 90, 92, and 94 of the respective components.

[0079] The second coolant path 56, the third coolant path 58 and / or the fourth coolant path 60 can be fluidically connected (arranged) in parallel.

[0080] The first coolant path 54 and the second coolant path 56 can be fluidically connected (arranged) in series. The first coolant path 54 and the third coolant path 58 can be fluidically connected (arranged) in series. The first coolant path 54 and the fourth coolant path 60 can be fluidically connected (arranged) in series.

[0081] The hydraulic resistance R of cooling circuit 12 can be determined based on the first hydraulic resistance R1, the second hydraulic resistance R2, the R.413680

[0082] - 12 - third hydraulic resistance R3 and / or the fourth hydraulic resistance R4 are calculated:

[0083] R = R1 + 1 / (1 / R2 + 1 / R3 + 1 / R4)

[0084] In the event that valve 50 is completely off (R4 would then be infinitely large), the coolant path 60 (i.e. the term 1 / R4) can be omitted from the calculation (see equation above).

[0085] The calculation of the hydraulic resistance R can depend on the respective fluidic connection (series and / or parallel) and can be implemented using the calculation rules for series or parallel connections.

[0086] This allows the pressure P of the coolant 14 (at the position marked by the virtual pressure sensor 13 in Figure 2) to be calculated from a multiplication of the flow rate Q of the coolant 14 and the hydraulic resistance R of the cooling circuit 12:

[0087] P = R x Q

[0088] The above calculations assume that the coolant 14 is liquid and therefore incompressible.

[0089] The first coolant path 54, the second coolant path 56, the third coolant path 58, the fourth coolant path 60, the cooling circuit 12 and / or the drive arrangement 10 can each be designed without a pressure sensor, i.e. without a physical pressure sensor.

[0090] The following describes a method for operating a drive arrangement 10 according to the above descriptions, with reference to Figures 1 to 4. The drive arrangement 10 can be one of the drive arrangements 10 shown in Figures 1 to 4. The method comprises the step:

[0091] Determining the pressure P of the coolant 14 within the cooling circuit 12 using the prediction model. The pressure P of the coolant 14 can be determined at the position in the cooling circuit 12 where the virtual pressure sensor 13 is located in R.413680.

[0092] - 13 -

[0093] Figure 1 or Figure 2 illustrates this. The determination of the pressure P can be implemented according to the above explanations, in particular calculated using the above equations.

Claims

R.413680 - 14 - 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: a coolant reservoir (16) for storing the coolant (14), a coolant pump (18) for conveying the coolant (14) within the cooling circuit (12), a temperature sensor (20) for determining a temperature of the coolant (14), at least one component (22) that can be supplied with the coolant (14), wherein the drive arrangement (10), in particular the cooling circuit (12), is configured to determine a pressure of the coolant (14) within the cooling circuit (12) by means of a predictive model.

2. Drive arrangement (10) according to claim 1, characterized in that the component (22) is a heat exchanger (24), a bypass line (26) for bypassing the heat exchanger (24), a first valve (28) for directing the coolant (14) through the Heat exchanger (24) and / or the bypass line (26), at least one first coolant line (30) for fluidic coupling of the heat exchanger (24), the bypass line (26) and / or the first valve (28), an electric machine (32) with a stator (34) and a rotor (36), a second valve (38) for directing the coolant (14) through the electric machine (32), the stator (34) and / or the rotor (36), at least one second coolant line (40) for fluidic coupling of the electric machine (32), the stator (34), the rotor (36) and / or the second valve (38), R.413680 - 15 - a gearbox (42), a third valve (44) for directing the coolant (14) through the gearbox (42), at least a third coolant line (46) for fluidically coupling the gearbox (42) and / or the third valve (44), a parking lock (48) for interrupting a torque within the drive arrangement (10), a fourth valve (50) for directing the coolant (14) to the parking lock (48) and / or at least a fourth coolant line (52) for fluidically coupling the parking lock (48) and / or the fourth valve (50).

3. Drive arrangement according to claim 1 or 2, characterized in that the prediction model is based on a flow rate of the coolant (14) and a hydraulic resistance of the cooling circuit (12), in particular wherein the pressure to be determined by means of the prediction model is calculated from a multiplication of the flow rate of the coolant (14) and the hydraulic resistance of the cooling circuit (12).

4. Drive arrangement (10) according to claim 3, characterized in that the flow rate of the coolant (14) is calculated on the basis of at least one parameter of the coolant pump (18), in particular a delivery rate of the coolant pump (18), and / or at least one parameter of the coolant (14), in particular the temperature of the coolant (14).

5. Drive arrangement (10) according to one of claims 2 to 4, characterized in that the drive arrangement (10), in particular the cooling circuit (12), comprises: a first coolant path (54) with a first hydraulic resistance, wherein the heat exchanger (24), the bypass line (26), the first valve (28) and / or the first coolant line (30) are arranged within the first coolant path (54), a second coolant path (56) with a second hydraulic resistance, wherein the electric machine (32), the stator (34), the rotor R.413680 - 16 - (36), the second valve (38) and / or the second coolant line (40) are arranged within the second coolant path (56), a third coolant path (58) with a third hydraulic resistance, wherein the transmission (42), the third valve (44) and / or the third coolant line (46) are arranged within the third coolant path (58), and / or a fourth coolant path (60) with a fourth hydraulic resistance, wherein the parking lock (48), the fourth valve (50) and / or the fourth coolant line (52) are arranged within the fourth coolant path (60), wherein the hydraulic resistance of the cooling circuit (12) is based on the first hydraulic resistance, the second hydraulic resistance, the third hydraulic resistance, the fourth hydraulic resistance, a switching state of the first valve (28), a switching state of the second valve (38), a switching state of the third valve (44),a switching state of the fourth valve (50), a leakage of the second coolant path (56), a leakage of the third coolant path (58), a temperature of the coolant (14) and / or at least one parameter of the coolant (14) is calculated.

6. Drive arrangement (10) according to claim 5, characterized in that the second coolant path (56), the third coolant path (58) and / or the fourth coolant path (60) are fluidically connected in parallel.

7. Drive arrangement (10) according to claim 5 or 6, characterized in that the first coolant path (54) and the second coolant path (56), the third coolant path (58) and / or the fourth coolant path (60) are fluidically connected in series.

8. Drive arrangement (10) according to one of the preceding claims, characterized in that the first coolant path (54), the second coolant path (56), the third coolant path (58), the fourth coolant path (60), the cooling circuit (12) and / or the drive arrangement (10) are each designed without pressure sensors. R.413680 - 17 - 9. Vehicle, in particular motor vehicle, comprising a drive arrangement (10) according to one of the preceding claims.

10. Method for operating a drive arrangement (10) according to any one of claims 1 to 8 comprising the step: Determining the pressure of the coolant (14) within the cooling circuit (12) using the prediction model.

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