Drive device with self-controlled cooling

Abstract

A drive arrangement, in particular for an electrically drivable vehicle, is disclosed, having at least one electric motor, having at least one drive inverter for actuating the electric motor, having at least one cooling unit, the cooling unit having at least one coolant pump, a cooler, at least one pump inverter and at least one heat exchanger, wherein the heat exchanger is fluidically connected to the coolant pump and the cooler by means of a coolant circuit, wherein at least one pump inverter is integrated into the drive inverter or is arranged adjacent to the drive inverter, wherein the coolant pump can be actuated by means of the pump inverter.

Description

TECHNICAL FIELD

[0001] The invention relates to a drive device, in particular for an electrically drivable vehicle, having at least one electric motor, having at least one drive inverter for actuating the electric motor, and having at least one cooling unit having at least one coolant pump, a cooler, at least one pump inverter and at least one heat exchanger. BACKGROUND

[0002] Electric drives are becoming increasingly important in the motorization of vehicles. In operation, the electric motor generates a loss power which has to be dissipated from the electric motor and the corresponding power electronics or inverter in the form of heat. In particular in highly efficient electric motors, external cooling of the components of the electric drive is necessary in order to be able to achieve operation of the components within their specifications.

[0003] The external cooling usually comprises a coolant pump which is actuated and supplied with electrical energy by separate data and supply lines. In order to improve the overall efficiency of the vehicle, the coolant pump is actuated as required. Thereby, in the case of high power requirements of the electric drive, the coolant pump can also require an increased cooling power. This optimization of the cooling power provided at vehicle level is usually complex and technically costly. Furthermore, the installation effort for the electrical connection of the cooling device to the central controller is cumbersome. SUMMARY

[0004] It can be the object underlying the invention to propose a drive device having a cost-efficient and compact cooling device.

[0005] This object is solved by means of the respective subject matter of the independent claims. Advantageous design solutions of the invention are the subject matter of the dependent claims, respectively.

[0006] According to one aspect of the invention, a drive device, in particular for an electrically drivable vehicle, is provided. The drive device has at least one electric motor and at least one drive inverter for actuating the electric motor.

[0007] Furthermore, at least one cooling unit is provided with at least one coolant pump, a cooler, at least one pump inverter and at least one heat exchanger. The heat exchanger is fluidically connected to the coolant pump and the cooler by means of a coolant circuit.

[0008] Preferably, the at least one pump inverter is integrated into the drive inverter or arranged adjacent to the drive inverter, wherein the coolant pump is actuable by means of the pump inverter.

[0009] The drive arrangement thus combines the aggregates from the drive train with aggregates from the HVAC / cooling domain. Thereby a cheaper overall system and vehicle can be provided. Here, the drive inverter can take over the actuation of the coolant pumps of the electric drive. This is achieved by integrating one or more corresponding pump inverters into the drive inverter or arranging the pump inverters next to the drive inverter.

[0010] The drive inverter is set up for actuating the at least one electric motor and can convert a direct voltage of a traction battery or a direct voltage source to operate the electric motor. For example, the drive inverter can convert the direct voltage into an alternating voltage in order to actuate the electric motor via three or six phases. Here, the drive inverter can have a data interface via which, for example, power requirements can be notified to the drive inverter.

[0011] The pump inverter can actuate one or more coolant pumps and thus enable the delivery of coolant in a coolant circuit. Here, the pump inverter can set a higher or lower volume flow of coolant depending on the required power of the drive components.

[0012] With the drive arrangement according to the application, the electrical axle can be realized with self-controlled or self-managed cooling. Synergies arise, in particular, in terms of power and / or data supply, since the power and / or data supply is supplied centrally from the axle-side or motor-side drive inverter.

[0013] The integration of the cooling aggregate-actuation into the drive inverter makes the drive inverter a closed, easy-to-apply system. In particular, a technically costly implementation of the communication of the coolant flow volume between the coolant pumps, the central controller and the drive components can be eliminated. Thus, the drive components, for example the electric motor and the drive inverter, can provide their own cooling and in this way take over the thermal, electrical and mechanical control in the electric vehicle. A multifunctional drive arrangement results, which can be designed independently for torque control (traction and deceleration by recuperation).

[0014] As an important interface of the superior vehicle controller, the drive arrangement designed as a unit can have a data interface. Via the data interface, lateral-target value presets, for example torque presets, force presets or acceleration presets, can be exchanged with the central vehicle controller.

[0015] A further advantage lies in the reduced wiring effort due to the elimination of the data lines and energy supply lines of the at least one cooling unit. The coolant pumps can be electrically connected by the central data and energy supply of the drive components. Here, the optimized spatial arrangement of the drive inverter, the electric motor and the pump inverter can allow a joint use of the cooling surface in order to simplify the thermal design of the pump inverter and the drive arrangement.

[0016] Furthermore, the installation effort of the drive arrangement can be reduced by integrating the pump inverter into the drive inverter. Here, the components can be fixed with a smaller number of screwing points and take up a smaller installation space in the vehicle.

[0017] The drive arrangement can preferably be used in an electrically drivable vehicle. Such a vehicle can be, for example, an electric vehicle or a hybrid vehicle.

[0018] The vehicle can be operated according to the BASt standard with assistance, partially automated, highly automated and / or fully automated or driverless.

[0019] The vehicle can be, for example, a passenger car, a truck, a robot taxi or the like. The vehicle is not limited to being operated on a road. Rather, the vehicle can also be designed as a ship, an aircraft, for example, a transport drone or the like.

[0020] In one embodiment, the electric motor and the drive inverter are designed as an electric axle. Alternatively or additionally, the transmission of the electric motor can also be integrated into the electric axle or e-axle. Thus, the drive arrangement can be embodied as a self-cooled e-axle, which can be optimized internally with regard to the required cooling.

[0021] By this measure, the energy uptake of the coolant pump can be minimized and the self-protection or service life of the cooled drive components can be increased.

[0022] According to a further embodiment, the pump inverter is arranged in a common housing of the drive inverter. Thereby, a spatial coupling of the drive inverter and the pump inverter can be realized. By this spatial coupling, a synergy effect in the thermal regulation of the inverters can be utilized, for example, by a common cooling body.

[0023] Furthermore, a functional coupling of the inverters can be realized. The functional coupling can be used to jointly use electronic components, for example, microprocessors and ASIC protection circuits, for a plurality of inverters.

[0024] According to a further embodiment, the coolant pump is arranged adjacent to the electric motor and / or the drive inverter. Thereby, the coolant pump can be spatially assigned to the drive components and the pump inverter. Here, the coolant lines and the electrical lines can be shortened and the installation effort of the drive arrangement can be reduced.

[0025] According to a further embodiment, the electric motor, the drive inverter and / or the pump inverter have a common heat exchanger, which is fluidically connected to the coolant pump. By this measure, a technically particularly simple drive arrangement can be provided. All drive components or only the pump inverter with the drive inverter can use a common heat exchanger and / or a common cooling surface and thus the complexity of the thermal management can be reduced.

[0026] According to a further embodiment, the drive inverter and the at least one pump inverter are thermally connected with a common heat exchanger or with separate heat exchangers. Thus, both inverters can have a common cooler or heat exchanger. Alternatively or additionally, separate cooling bodies with different cooling circuit temperatures can be provided depending on the operating temperature of the inverters.

[0027] The respective coolant circuits can be decoupled from one another. Here, each inverter can have its own coolant circuit.

[0028] According to a further embodiment, the electric motor is thermally coupled with a first heat exchanger, which is fluid-conductively connected with a first cooling unit by means of a first coolant circuit.

[0029] Preferably, the drive inverter and / or the at least one pump inverter are thermally coupled with at least one second heat exchanger, which is fluid-conductively connected with a second cooling unit by means of a second coolant circuit. In this design, the at least one electric motor can be thermally conditioned by a cooling unit, which is different from the cooling unit of the inverters. By this measure, different temperature levels for the electric motor and for the power electronics, which are used in the form of the drive inverter and the pump inverter for actuating the electric motor and the pump motor, can be achieved. For example, the electric motor can be operated at a higher temperature level relative to the power electronics. Thus, the cooling of the drive device can be particularly efficient.

[0030] According to a further embodiment, the at least one coolant circuit has a coolant, wherein the coolant is designed as oil, water, air or an aqueous solution. Thereby, the thermal conditioning of the drive components can be realized in a particularly versatile manner.

[0031] For example, the electric motor can be cooled with a different cooling medium than the inverters.

[0032] The different coolant circuits can have the same or different coolants.

[0033] In the following, preferred embodiments of the application are explained in more detail with the aid of highly simplified schematic drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A schematic diagram of a drive device according to one embodiment is shown,

[0035] Figure 2 A schematic diagram of a drive device according to a further embodiment is shown,

[0036] Figure 3 A schematic diagram of a drive device with separate coolant circuits according to one embodiment is shown, and

[0037] Figure 4 A schematic diagram of a drive arrangement with a separate coolant circuit is shown according to a further embodiment. DETAILED DESCRIPTION

[0038] In Figure 1 A schematic diagram of a drive arrangement 1 according to an embodiment is shown in Fig. 1. The drive arrangement 1 can be used in an electrically drivable vehicle, for example an electric vehicle or a hybrid vehicle.

[0039] The drive arrangement 1 shown in the embodiment has an electric motor 2 and a drive inverter 4 for operating the electric motor 2. The drive inverter 4 can supply and regulate electrical energy provided by a traction battery 6 to the electric motor 2. For example, the drive inverter 4 can supply the energy provided by the traction battery 6 as a direct voltage to the electric motor 2 in the form of an alternating voltage.

[0040] As an interface to a superordinate vehicle controller 8, the drive arrangement 1 can have a data interface 10. Through the data interface 10, lateral-target value specifications, for example torque specifications, force specifications or acceleration specifications, can be exchanged with the central vehicle controller 8.

[0041] Furthermore, the drive arrangement 1 has a cooling unit 12. The cooling unit 12 can have, for example, a cooler 14, a pump inverter 16 and a coolant pump 18. The cooling unit 12 can be realized by means of a heat exchanger 20.

[0042] The pump inverter 16 serves to operate the coolant pump 18 and is preferably integrated into the drive inverter 4 or arranged adjacent to the drive inverter 4.

[0043] The electric motor 2, the drive inverter 4 and the pump inverter 16 can be designed as one unit, for example an electric axle.

[0044] The coolant pump 18 can convey coolant in a coolant circuit 22. The coolant circuit 22 connects the coolant pump 18 with the cooler 14 and the heat exchanger 20.

[0045] The heat exchanger 20 is provided for transporting the loss power and waste heat of the drive inverter 4, the electric motor 2 and the pump inverter 16 into the coolant. The heat absorbed by the coolant can then be released in the cooler 14.

[0046] By integrating the pump inverter 16 into the electric axle, it can also be supplied with power through the interface of the drive inverter 4. Furthermore, the power requirement of the coolant pump 18 can be directly known on the electric axle to be cooled. The operation of the coolant pump 18 is directly carried out by means of the pump inverter 16.

[0047] The coolant in the coolant circuit 22 can be, for example, an aqueous solution.

[0048] Figure 2A drive arrangement 1 according to another embodiment is shown in a schematic view. As in the Figure 1 Unlike the drive arrangement 1 shown in

[0049] Furthermore, the drive arrangement 1 has, in the shown embodiment, an arrangement of the cooling units 12 and the electrical shafts 4, 2, 16 in a common housing 26. Thereby, the entire drive arrangement 1 can be designed as a unit which can be installed simply.

[0050] In Figure 3 A schematic view of a drive arrangement 1 according to one embodiment with separate coolant circuits 22.1, 22.2 is shown in

[0051] The electric motor 2 is thermally coupled with a first heat exchanger 20.1 which is fluid conductively connected with a first cooling unit 12.1 by a first coolant circuit 22.1. The first heat exchanger 20.1 is supplied with coolant by the first cooling unit 12.1. Here, a first coolant pump 18.1 conveys coolant in the first coolant circuit 22.1.

[0052] A second coolant circuit 22.2 is operated by a second cooling unit 12.2 with a second coolant pump 18.2. Here, a second heat exchanger 20.2 is fluid conductively connected with the second coolant circuit 22.2.

[0053] The first coolant pump 18.1 is operated by a first pump inverter 16.1 and the second coolant pump 18.2 is operated by a second pump inverter 16.2 and is supplied with electrical energy.

[0054] The first cooling unit 12.1 can set a first temperature level or heat transfer in the first heat exchanger 20.1 for thermal conditioning of the electric motor 2 with the first coolant circuit 22.1.

[0055] The second cooling unit 12.2 can set a second temperature level or heat transfer in the second heat exchanger 20.2 for thermal conditioning of the drive inverter 4 and the second pump inverter 16.2 with the second coolant circuit 22.2. The first pump inverter 16.1 can here likewise be cooled by the second heat exchanger 20.2.

[0056] The heat exchangers 20 are in principle not only suitable for cooling components. Depending on the design of the drive arrangement 1, the heat exchangers 20 can also be used for heating components in order to be able to realize an operation of the components within an optimum specification.

[0057] Figure 4A schematic diagram of a drive arrangement 1 with separate coolant circuits 22.1, 22.1 is shown according to a further embodiment. In contrast to the embodiment shown in Figure 3 The drive arrangement 1 has a separate heat exchanger 20.2, 20.3, 20.4 for each inverter 4, 16.1, 16.2. The heat exchangers 20.2, 20.3, 20.4 are all in common fluidically connected with the second coolant circuit 22.2.

[0058] For the sake of clarity, the cooler 14 is not shown in Figure 3 and Figure 4

[0059] According to an alternative design, it is also possible to use multiple coolant circuits decoupled from each other in order to cool different inverters 4, 16.1, 16.2. For example, each inverter 4, 16.1, 16.2 can be cooled by a heat exchanger 20.2, 20.3, 20.4 fluidically coupled with a separate coolant circuit, respectively.​

Claims

1. A drive device (1), particularly for an electrically driven vehicle, the drive device having -At least one electric motor (2), - At least one drive inverter (4) for controlling the motor (2), - At least one cooling unit (12) having at least one coolant pump (18), a cooler (14), at least one pump inverter (16), and at least one heat exchanger (20), wherein, The heat exchanger (20) is fluidly connected to the coolant pump (18) and the cooler (14) via a coolant circuit (22). The device is characterized in that at least one pump inverter (16) is integrated into or arranged adjacent to the drive inverter (4), wherein the coolant pump (18) is operable by the pump inverter (16), wherein the motor (2), the drive inverter (4) and the pump inverter (16) are designed as electric shafts, and wherein a heat exchanger (20) is provided for transporting the power loss and waste heat of the drive inverter (4), the motor (2) and the pump inverter (16) to the coolant.

2. The driving device according to claim 1, wherein, The electric motor (2) and the drive inverter (4), or the electric motor (2), the drive inverter (4) and the transmission device are designed as electric shafts.

3. The driving device according to claim 1 or 2, wherein, The pump inverter (16) is arranged in the common housing (26) of the drive inverter (4).

4. The driving device according to any one of claims 1 to 3, wherein, The coolant pump (18) is arranged adjacent to the motor (2) and / or the drive inverter (4).

5. The driving device according to any one of claims 1 to 4, wherein, The electric motor (2), the drive inverter (4) and / or the pump inverter (16) have a common heat exchanger (20) which is fluidly connected to the coolant pump (18).

6. The drive device according to any one of claims 1 to 4, wherein, The drive inverter (4) and the at least one pump inverter (16) are thermally connected to a common heat exchanger (20.2) or to separate heat exchangers (20.2, 20.3, 20.4).

7. The driving device according to any one of claims 1 to 4, wherein, The motor (2) is thermally coupled to a first heat exchanger (20.1), which is fluidly connected to a first cooling unit (12.1) via a first coolant circuit (22.1). The drive inverter (4) and / or at least one pump inverter (16) are thermally coupled to at least one second heat exchanger (20.2), which is fluidly connected to a second cooling unit (12.2) via a second coolant circuit (22.2).

8. The drive device according to any one of claims 1 to 7, wherein, The at least one coolant circuit (22) has a coolant, wherein the coolant is oil, water, air or an aqueous solution.

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