Electric drive device for a vehicle

Abstract

The invention relates to an electric drive device (1) for a vehicle, comprising an electric machine (12), an inverter (13) electrically connected to the electric machine (12), and a refrigerant compressor (14). The electric drive device (1) has a housing (10) having a first chamber (22) in which the electric machine (12) is arranged and having a second chamber (23) in which the inverter (13) is arranged and having a separating wall (45) which separates the first chamber (22) from the second chamber (23). A cooling channel (30) for cooling the inverter (13) is provided in the separating wall (45). The cooling channel (30) has an inlet (31) and an outlet (32). The refrigerant compressor (14) is arranged in a refrigerant compressor housing (24) of the electric drive device (1). The refrigerant compressor housing (24) has a refrigerant inlet (25) for admitting the refrigerant (70) to be compressed into the refrigerant compressor housing (24) and has a refrigerant outlet (26) for discharging the compressed refrigerant (70) from the refrigerant compressor housing (24). The outlet (32) of the cooling channel (30) is connected to the refrigerant inlet (25) of the refrigerant compressor housing (24).

Description

[0001] R. 415160

[0002] - 1 -

[0003] Description

[0004] title

[0005] Electric drive device for a vehicle

[0006] State of the art

[0007] From DE 102015225 103 A1, a drive train for a vehicle is already known, comprising an electric motor for driving the vehicle, a refrigeration circuit with an air conditioning compressor, an evaporator, a condenser, and an expansion valve for cooling the vehicle's interior, and a drive unit for mechanically driving the air conditioning compressor. The electric motor is mechanically coupled to the air conditioning compressor via a mechanical compressor coupling device, so that the electric motor serves to drive the vehicle in addition to mechanically driving the air conditioning compressor.

[0008] The aforementioned publication further proposes combining the electric machine, a gearbox, the air conditioning compressor, the compressor coupling means, a drive coupling means and power electronics for the electric machine into a single unit and / or arranging the electric machine, the gearbox, the air conditioning compressor, the compressor coupling means, the drive coupling means and the power electronics for the electric machine within a single or multi-part, common housing.

[0009] The aforementioned publication further proposes to thermally connect the evaporator of the refrigeration circuit to the power electronics in order to conduct waste heat from the power electronics to the evaporator.

[0010] Disclosure of the invention

[0011] The present invention is based on the desire to create an electric drive unit that ensures semiconductor components of an inverter of the electric drive unit can be operated at comparatively low temperatures. Operation at low temperatures R. 415160

[0012] - 2 -

[0013] Temperatures allow for further miniaturization of the inverter's semiconductor components, such as power semiconductor components. This reduces the area required for components like chips and consequently the installation space needed for the inverter itself. The result is a more compact drive unit design and significant cost advantages.

[0014] The invention makes it possible, for example, to operate the inverter in a temperature range between 20°C and 60°C.

[0015] According to the invention, a drive device for a vehicle, comprising an electric machine, an inverter electrically connected to the electric machine, a refrigerant compressor, and optionally a transmission mechanically coupled to the electric machine, has a housing comprising a first chamber in which the electric machine is arranged, a second chamber in which the inverter is arranged, and a partition separating the first chamber from the second chamber. A cooling channel for cooling the inverter is provided in the partition. The cooling channel has an inlet and an outlet. The refrigerant compressor is arranged in a refrigerant compressor housing of the electric drive device.The refrigerant compressor housing has a refrigerant inlet for the intake of the refrigerant to be compressed and a refrigerant outlet for the exhaust of the compressed refrigerant from the refrigerant compressor housing. According to the invention, the outlet of the cooling channel is fluidically connected to the refrigerant inlet of the refrigerant compressor housing.

[0016] By positioning the cooling channel upstream of the refrigerant compressor, it can transfer the cooling effect of the refrigerant through the partition to the inverter before the refrigerant reaches the compressor. This allows the inverter to operate at comparatively low temperatures.

[0017] In a first, modular embodiment, the housing is detachably connected to the refrigerant compressor housing, for example R. 415160

[0018] - 3 - is screwed together. This design is particularly flexible.

[0019] In a further development, the outlet of the cooling channel can be directly connected to the refrigerant inlet of the refrigerant compressor housing, for example, by a detachable connection between a flange of the housing and a flange of the refrigerant compressor housing, such as a bolted connection. Thus, no hoses, pipes, or other such refrigerant-carrying connecting elements are provided between the flanges or between the outlet of the cooling channel and the refrigerant inlet of the refrigerant compressor housing. This results in a compact design of the device according to this embodiment.

[0020] In a second, more integrated embodiment, the housing and the refrigerant compressor housing are designed as a single, monolithic unit, so that the cooling channel outlet and the refrigerant inlet of the refrigerant compressor housing are realized in a continuous cooling channel of the entire housing. This reduces the number of interfaces in the refrigerant circuit.

[0021] The overall housing can be, for example, a die-cast or cast part. It can be made of aluminum, for instance.

[0022] The first chamber of the housing can, for example, have a cylindrical shape. The refrigerant compressor housing can be arranged on its outer surface.

[0023] The second chamber of the housing can also be located on the outer surface.

[0024] It may be provided that the second chamber and the refrigerant compressor housing are arranged circumferentially at a right angle or approximately at a right angle (e.g. between 85° and 95°) to each other.

[0025] It may be provided that the second chamber and the refrigerant compressor housing, and in particular also the first chamber, extend identically or approximately identically in the axial direction, for example with extensions that overlap each other by at least 80%. R. 415160

[0026] - 4 -

[0027] The invention also relates to a coolant circuit for an electrically powered vehicle, which has a passenger compartment and an electric drive device according to one of the preceding claims, wherein the coolant circuit extends from the inlet of the cooling channel to the outlet of the cooling channel, then further to the refrigerant inlet of the refrigerant compressor housing, then further to the refrigerant outlet of the refrigerant compressor housing and then further via an evaporator provided for cooling the passenger compartment, back to the inlet of the cooling channel.

[0028] It is preferably provided that the refrigerant circulates in the coolant circuit driven by the refrigerant compressor and has a temperature between 0°C and 60°C, for example between 20°C and 60°C, at least within the cooling channel. The semiconductor components of the inverter are then preferably also operated within this temperature range.

[0029] Figures 1 to 3 show an example of a partially assembled electric drive unit according to the invention.

[0030] The housing 10 of the drive unit 1 comprises a first chamber 22, which has a cylindrical shape and into which an electric machine 12 of the drive unit 1 is to be placed (see, for example, Figure 1, in which the electric machine 12 is only symbolically indicated by its reference numeral 12 for clarity). Separated by a partition 45 of the housing 10, a second chamber 23 of the housing 10 is provided on its circumference. An inverter 13 of the drive unit 1 is arranged in this chamber and is electrically connected to the electric machine 12. Extending axially from the first chamber 22, the drive unit 1 can have a transmission 11 that is mechanically coupled to the electric machine 12 to transmit drive torques. The transmission can, for example, include a differential gear to adequately drive two wheels of a driven axle of the vehicle.For clarity, the gearbox 11 is only symbolically indicated in Figure 1 by its reference numeral 11. R. 415160.

[0031] - 5 -

[0032] The refrigerant compressor 14 is also arranged on the circumferential wall of the cylindrical first chamber 22 of the housing 10, approximately at right angles to the second chamber 23 along the circumference. In this example, it has a refrigerant compressor housing 24, which is mounted to the housing 10 by means of screws 50, three of which are visible in Figure 1. An electric drive for the refrigerant compressor 14 can, for example, be electrically connected to the inverter 13 for the purpose of supplying power to the drive.

[0033] The first and second chambers 22, 23 of the drive unit 1 can be closed by covers, which are not shown in Figure 1 for clarity.

[0034] As shown, for example, in Figure 2, the partition 45 has a cooling channel 30 that extends diagonally across the base of the second chamber 23, from an inlet 31, which is designed, for example, as an inlet flange, to an outlet 32, which is designed, for example, as an outlet flange, in a top view of the drive unit 1. In this example, the cooling channel 30 also runs below a flat cooling surface of the housing 10, which is provided for thermally conductive contact with semiconductor components of the inverter 13. The flow of a refrigerant 70 through inlet 31, cooling channel 30, and outlet 31, as provided in this example, is symbolized by arrows 101, 102, and 103 with respect to its path and direction of flow.

[0035] A refrigerant inlet 25 of the refrigerant compressor housing 24 is shown in Figure 3. It can also be seen that the refrigerant inlet 25 of the refrigerant compressor housing 24 is designed as a flange, which is directly connected to the outlet flange of the cooling channel 30 (i.e., without any further connection via an intervening pipe, hose, or similar component), here by means of a screw connection. Although the refrigerant outlet of the refrigerant compressor housing 24 is not visible in Figure 3, it is nevertheless present and is, for example, designed as a flange.

[0036] A coolant circuit 100, in which the drive unit 1 described above (Figures 1, 2 and 3) is integrated, is shown by way of example in Figure 4. A refrigerant 70 circulates in the coolant circuit 100, which is symbolized by the arrows 104. R. 415160

[0037] - 6 -

[0038] The refrigerant circuit 100 comprises the drive unit 1 described above (Figures 1, 2, and 3) by way of example, wherein the refrigerant 70 circulates from the inlet 31 of the cooling channel 30 to the outlet 32 ​​of the cooling channel 30, then on to the refrigerant inlet 25 of the refrigerant compressor housing 24, and then on to the refrigerant outlet 26 of the refrigerant compressor housing 24. From there, the refrigerant 70 circulates further via a condenser 120 of the refrigerant circuit 100, to a filter drier 130 of the refrigerant circuit 100, and via an expansion valve 140 to an evaporator 110 of the refrigerant circuit 100. The evaporator 110 is designed to deliver cooling to the passenger compartment of a vehicle, for example, by means of a fan. From the evaporator 110, the refrigerant 70 circulates back to the inlet 31 of the cooling channel in order to also cool the inverter 13 of the drive unit.

Claims

R. 415160 - 7 - Claims 1. Electric drive device (1) for a vehicle, comprising an electric machine (12), an inverter (13) electrically connected to the electric machine (12), a refrigerant compressor (14), and optionally a transmission (11) mechanically coupled to the electric machine (12), wherein the electric drive device (1) has a housing (10) having a first chamber (22) in which the electric machine (12) is arranged, and having a second chamber (23) in which the inverter (13) is arranged, and having a partition (45) separating the first chamber (22) from the second chamber (23), wherein a cooling channel (30) for cooling the inverter (13) is provided in the partition (45), wherein the cooling channel (30) has an inlet (31) and an outlet (32), and wherein the refrigerant compressor (14) is arranged in a refrigerant compressor housing (24) of the electric drive device (1).wherein the refrigerant compressor housing (24) has a refrigerant inlet (25) for the inlet of the refrigerant (70) to be compressed into the refrigerant compressor housing (24) and a refrigerant outlet (26) for the outlet of the compressed refrigerant (70) from the refrigerant compressor housing (24), wherein the outlet (32) of the cooling channel (30) is connected to the refrigerant inlet (25) of the refrigerant compressor housing (24).

2. Electric drive device (1) according to claim 1, wherein the housing (10) is detachably connected to the refrigerant compressor housing (24), for example by screwing, and the outlet (32) of the cooling channel (30) is directly connected to the refrigerant inlet (25) of the refrigerant compressor housing (24).

3. Electric drive device (1) according to claim 2, wherein a flange of the housing (10) is detachably connected to a flange of the refrigerant compressor housing (24), for example by screwing, in order to connect the outlet of the cooling channel (30) directly to the refrigerant inlet (25) of the R. 415160 - 8 - to connect refrigerant compressor housing (24).

4. Electric drive device (1) according to claim 1, wherein the housing (10) with the refrigerant compressor housing (24) are designed as a one-piece monolithic overall housing (34), such that the outlet (32) of the cooling channel and the refrigerant inlet (25) of the refrigerant compressor housing (24) are realized in a continuous overall cooling channel of the overall housing (34).

5. Electric drive device (1) according to claim 4, wherein the overall housing (34) is a cast or die-cast part and wherein the overall housing (34) is made of aluminium.

6. Electric drive device (1) according to one of the preceding claims, wherein the first chamber (22) of the housing has a cylindrical shape and wherein the refrigerant compressor housing (24) is arranged on its outer surface.

7. Electric drive device (1) according to claim 6, wherein the second chamber (23) is arranged on the outer surface.

8. Electric drive device (1) according to claim 6 or 7, wherein the second chamber and the refrigerant compressor housing are arranged circumferentially at approximately a right angle to each other.

9. Electric drive device (1) according to claim 6 or 7, wherein the second chamber (23) and the refrigerant compressor housing (24) extend in approximately the same axial direction.

10. Coolant circuit (100) for an electrically powered vehicle comprising a passenger compartment and an electric drive device (1) according to one of the preceding claims, wherein the coolant circuit (100) extends from the inlet (31) of the cooling channel (30) to the outlet (32) of the cooling channel (30), then further to the refrigerant inlet (25) of the refrigerant compressor housing (24), then further to the refrigerant outlet (26) of the refrigerant compressor housing (24) and then further via an evaporator (110) provided for cooling the passenger compartment. R. 415160 - 9 - extends to the inlet (31) of the cooling channel (30).

11. Coolant circuit (100) according to claim 6, wherein a refrigerant (70) is provided in the coolant circuit (100).

12. Method for operating the coolant circuit (100) according to claim 7, wherein the refrigerant (70) circulates in the coolant circuit (100) driven by the refrigerant compressor (14) and has a temperature between 0°C and 60°C at least within the cooling channel (30).

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