Lubricant supply for an electric drive system and motor vehicle with such a lubricant supply

Abstract

A lubricant supply for a powertrain in an electrically driven motor vehicle has a hydraulic oil pump, which can be driven by a drive actuator, a lubricant supply point and a lubricant reservoir. The hydraulic oil pump can generate a first lubricant volume flow from the lubricant reservoir to the lubricant supply point and a second lubricant flow volume from the lubricant supply point or an additional lubricant supply point in the lubricant reservoir. The drive actuator is an electric motor. The lubricant supply point is arranged in a traction motor with a rotor shaft and a motor housing. The additional lubricant supply location is disposed in a traction transmission. The lubricant supply points can be supplied with lubricant by way of the first lubricant volume flow.

Claims

1. A lubricant supply for a drive train in an electrically driven motor vehicle, comprising: a lubricating oil pump configured as a double pump comprising a scavenge pump and a pressurized oil pump, which are drivable commonly by way of an electric motor drive actuator and are couplable to a common drive shaft of the electric motor drive actuator for drive purposes, a first lubricant supply point arranged in a traction motor having a rotor shaft and a motor housing; a further lubricant supply point arranged in a traction transmission; and a lubricant reservoir, wherein a first lubricant volumetric flow from the lubricant reservoir to the first and further lubricant supply points is producible by the pressurized oil pump, a second lubricant volumetric flow from at least one of the first or further lubricant supply points into the lubricant reservoir is producible by the scavenge pump, and the second lubricant volumetric flow which is producible is greater than the first lubricant volumetric flow which is producible.

2. The lubricant supply as claimed in claim 1, wherein the first or the second lubricant volumetric flow is guided through a heat exchanger.

3. The lubricant supply as claimed in claim 2, wherein the heat exchanger is bypassable by way of a bypass, and a bypass valve is provided in order to control said bypass.

4. The lubricant supply as claimed in claim 1, further comprising: a transmission arranged between the pressurized oil pump and the scavenge pump for transmitting power from the pressurized oil pump to the scavenge pump, wherein said transmission is configured such that a drive speed of the scavenge pump in operation as planned of the double pump is greater than a drive speed of the pressurized oil pump.

5. The lubricant supply as claimed in claim 1, wherein lubricant delivery volume per revolution of the common drive shaft is greater in the case of the scavenge pump than in the case of the pressurized oil pump.

6. The lubricant supply as claimed in claim 5, wherein the scavenge pump and the pressurized oil pump in each case have a pump rotor which is rotatable in order to produce the respective lubricant volumetric flow, and said pump rotors are arranged concentrically with respect to one another.

7. The lubricant supply as claimed in claim 1, wherein a lubricant collecting region is arranged in the traction transmission, and the second lubricant volumetric flow is dischargeable from said lubricant collecting region to the scavenge pump.

8. The lubricant supply as claimed in claim 1, wherein the first and further lubricant supply points are suppliable in each case with a part volumetric flow from the first lubricant volumetric flow.

9. The lubricant supply as claimed in claim 1, wherein lubricant from the first lubricant volumetric flow is feedable to the traction motor by way of the rotor shaft, a lubricant collecting region is arranged in the motor housing, and the second lubricant volumetric flow is dischargeable from said lubricant collecting region to the scavenge pump.

10. The lubricant supply as claimed in claim 1, wherein the traction motor has a stator, the stator is temperature controllable by way of a cooling jacket in the motor housing, and lubricant from the first lubricant volumetric flow is feedable to the cooling jacket.

11. The lubricant supply as claimed in claim 1, wherein the lubricant reservoir has an overflow line, and the overflow line is set up to establish a fluid-conducting connection between the lubricant reservoir and one of the first and further lubricant supply points.

12. The lubricant supply as claimed in claim 1, further comprising: an air separator in the second lubricant volumetric flow downstream of the scavenge pump.

13. An electrically driven motor vehicle comprising the lubricant supply as claimed in claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a diagrammatic lubricating supply having a double pump.

(2) FIG. 2 is a diagrammatic lubricating supply having a single pressurized oil pump.

DETAILED DESCRIPTION OF THE DRAWINGS

(3) FIG. 1 shows a diagrammatic lubricant supply. The lubricant supply has a double pump 1. The double pump 1 has a pressurized oil pump 3 and a scavenge pump 4. The pressurized oil pump 3 and the scavenge pump 4 are connected to one another fixedly via the connecting shaft 20 so as to rotate together. Here, the drive power which is provided by the common drive actuator, which is configured as an electric motor 2, is transmitted by way of the common drive shaft 27 to the pressurized oil pump 3 and from the latter via the connecting shaft 20 to the scavenge pump 4. The two pumps 3, 4 are therefore driven by way of a common drive actuator.

(4) The pressurized oil pump 3 sucks lubricant via the suction line 5 from the lubricant reservoir which is configured as an oil tank 21, in order to produce a first lubricant volumetric flow. The first lubricant volumetric flow is fed to the lubricant supply points 32, 33 via the pressurized oil line 26 which is divided into the part lines 9, 10.

(5) A heat exchanger 6 is provided in the pressurized oil line 26. The throughflow through the heat exchanger 6 can be influenced by the valve 8 and the bypass line 7.

(6) Here, as an alternative to the embodiment which is shown, the valve 8 can also be arranged in the pressurized oil line 26, with the result that the throughflow through the heat exchanger 6 can be shut off completely and the entire volumetric flow can be conducted through the bypass line 7. A configuration of this type is possible independently of the remaining configuration of the lubricant supply.

(7) The first part line 9 opens into a bore 18 which is made in the rotor 13 of the traction motor 12. Both the rotor 13, the stator 24, and the motor housing 14 of the traction motor 12 can be supplied with lubricant by way of the outlet recesses 25 which can open into the air gap 35. A collecting region 15 for lubricant which flows back is provided in the stator 24 and/or in the motor housing 14.

(8) A second lubricant volumetric flow is produced via the suction line 23 by way of the scavenge pump 4, by which second lubricant volumetric flow the lubricant flows back out of the collecting region 15 via the air separator 28 into the oil tank 21.

(9) Lubricant can be fed via the second part line 10 to the further lubricant supply point 33 in the traction transmission 11, with the result that the gearwheels 17 can be supplied with lubricant.

(10) The oil tank 21 has an overflow line 16, by means of which a fluid-conducting connection is established between the oil tank and the traction motor 12 or the traction transmission 11 via the oil outlets 19.

(11) For the transmission of power, the traction transmission 11 has a series of gearwheels 17. The gearwheels 17 form the further lubricant supply point 33 in the traction transmission 11. The drive power which can be provided by the traction motor 12 is transmitted by way of the traction transmission 11 to the output shaft 25 and can be transmitted from the latter to a drive axle.

(12) FIG. 2 shows a diagrammatic illustration of a further lubricant supply. Here, the pressurized oil pump 3 which is driven by the electric motor 2 sucks lubricant directly via the suction line 23 out of the oil tank 21. The arrangement in relation to the heat exchanger 6, and the bypass line 7 and the bypass valve 8 are embodied as shown in FIG. 1.

(13) The traction motor 12 has a motor housing 14. A cooling jacket 34 is arranged in the motor housing 14. In a first variant, the cooling jacket 34 can be flowed through by the lubricant volumetric flow. A second variant provides that the cooling jacket 34 cannot be flowed through by lubricant, but rather by another cooling fluid, for example water. For the second variant, the lubricant volumetric flow is guided around the traction motor 12 by way of the hydraulic line 36.

(14) The lubricant can be conducted to the lubricant supply point 32 and the further lubricant supply point 33 by way of the first and second part lines 9, 10. From the first part line 9, the part volumetric flow passes through the bore 18 into the rotor 13 of the traction motor 12. Through the second part line 10, the second part volumetric flow passes to the gearwheels 17 in the traction transmission 11 and therefore to the further lubricant supply point 33.

(15) Via the return line 37, the lubricant passes back into the oil tank 21. A delivery action for the lubricant in the direction of the return line 37 results in the traction transmission 11 by way of the gearwheels 17.

(16) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.