Coolant supply system for an electrically operated vehicle axle

Patent metadata

Field	Value
Publication number	US-12249898-B2
Application number	US-202218699966-A
Country	US
Kind code	B2
Filing date	Jul 27, 2022
Priority date	Oct 28, 2021
Publication date	Mar 11, 2025
Grant date	Mar 11, 2025

Abstract

A coolant supply system for a drive device of an electrically operated vehicle axle with an electric machine which has a cylindrical stator housing, in which there is a winding head space axially on both sides of a rotor/stator arrangement, at the bottom of which coolant collects. The two winding head spaces are fluidly connected to one another via a coolant sump, and the stator housing height and the coolant sump height in the electric machine vertical direction add up to a total height. In order to reduce the total height, the coolant sump is offset by a transverse offset from a rotor axis vertical plane. In this way, the stator housing height and the coolant sump height can at least partially overlap in the vertical direction of the electric machine by an overlap amount.

First claim

The invention claimed is:

1. A coolant supply system for a drive device of an electrically operated vehicle axle of a vehicle with an electric machine which has a cylindrical stator housing, in which there is a winding head space axially on both sides of a rotor/stator arrangement, at the bottom of which coolant collects, wherein the two winding head spaces are fluidly connected to one another via a coolant sump, and
wherein the stator housing height and the coolant sump height in the electric machine vertical direction add up to a total height, wherein the stator housing height is measured from a suction point defined on a lower internal surface of the stator housing, and
wherein, in order to reduce the total height, the coolant sump is offset by a transverse offset from a rotor axis vertical plane, so that the stator housing height and the coolant sump height at least partially overlap in the electric machine vertical direction by an overlap amount, and
wherein the electric machine is mounted transversely on the vehicle such that the electric machine extends parallel to the vehicle axle,
wherein the coolant sump is divided into two slosh channels, which are arranged with a transverse offset on both sides of the rotor axis vertical plane, and
when the vehicle is driving uphill, the rear slosh channel in the direction of travel ensures a fluid connection between winding head spaces due to transverse force, or when the vehicle is driving downhill, the front slosh channel in the direction of travel ensures the fluid connection between the winding head spaces due to transverse force.

2. The coolant supply system according to claim 1 , wherein the coolant sump extends continuously in the stator housing axial direction over the entire stator housing axial length.

3. The coolant supply system according to claim 1 , wherein an electric machine hydraulic circuit is provided, in which the coolant sump is integrated, from which coolant can be returned at suction points by means of at least one return pump to a coolant tank.

4. The coolant supply system according to claim 1 , wherein a first suction point is positioned on one side of the vehicle and a second suction point is positioned on the other side of the vehicle, and when the vehicle is cornering to the left, the coolant in the coolant sump is displaced towards the right suction point due to centrifugal force, or when the vehicle is cornering to the right, the coolant in the coolant sump is displaced towards the left suction point due to centrifugal force, so that the coolant can be safely returned to the coolant tank either at the first or second suction point.

5. The coolant supply system according to claim 4 , wherein the first suction point is located close to the transmission, and wherein the second suction point is located remote from the transmission.

6. The coolant supply system according to claim 4 , wherein the vehicle is configured to safely return the coolant to the coolant tank during cornering.

7. The coolant supply system according to claim 1 , wherein in the drive device, the electric machine drives, via a transmission, flange shafts guided to the vehicle wheels, and a transmission hydraulic circuit is provided, in which a transmission chamber and a transmission sump formed on the transmission bottom are integrated, in which the coolant draining from transmission components collects at a transmission-side suction point, from which the coolant can be returned into the transmission tank with a transmission return pump and the transmission is arranged on a stator housing axial side.

8. The coolant supply system according to claim 7 , wherein an end wall of the stator housing close to the transmission has a coolant passage which connects the winding head space close to the transmission with the transmission sump, so that the transmission-side suction point has a dual function, namely not only of sucking out the coolant collecting in the transmission sump, but also of sucking the coolant transferred from the stator housing, and the coolant passage is positioned in vertical alignment with the rotor axis, and/or the sloshing channels are connected to the respective winding head space via coolant passages, and/or at least one of the sloshing channels is connected to the transmission sump via a channel opening.

9. The coolant supply system according to claim 1 , wherein the return pumps are arranged on a common stator housing axial side, and the suction point arranged on an axial side remote from the pump is connected via a return line to an electric machine return pump, and/or the slosh channel formed with the channel opening and the transmission-side suction point are positioned on the same side with respect to the rotor axis vertical plane, and/or the suction point remote from the transmission or pump and the sloshing channel which is not connected to the transmission sump are arranged on the opposite side of the rotor axis vertical plane, so that the two suction points are positioned in a diagonal arrangement with respect to the rotor axis vertical plane.

10. The coolant supply system according to claim 1 , wherein on a stator housing axial side, a transverse channel is formed, into which the two slosh channels and the return line open, and the transverse channel connects the two slosh channels with one another, and the transverse channel is connected to the winding head space at a coolant passage.

11. The coolant supply system according to claim 10 , wherein a sieve element can be inserted into the transverse channel, which element filters the coolant passing through.

12. The coolant supply system according to claim 10 , wherein the transverse channel is formed on the stator housing axial side remote from the transmission.

13. A coolant supply system for a drive device of an electrically operated vehicle axle of a vehicle with an electric machine which has a cylindrical stator housing, in which there is a winding head space axially on both sides of a rotor/stator arrangement, at the bottom of which coolant collects, wherein the two winding head spaces are fluidly connected to one another via a coolant sump, and wherein the stator housing height and the coolant sump height in the electric machine vertical direction add up to a total height, wherein the stator housing height is measured from a suction point defined on a lower internal surface of the stator housing, and
wherein, in order to reduce the total height, the coolant sump is offset by a transverse offset from a rotor axis vertical plane, so that the stator housing height and the coolant sump height at least partially overlap in the electric machine vertical direction by an overlap amount,
wherein an electric machine hydraulic circuit is provided, in which the coolant sump is integrated, from which at suction points coolant can be returned into a coolant tank by means of at least one return pump,
wherein the coolant sump is divided into two slosh channels, which are arranged with a transverse offset on both sides of the rotor axis vertical plane, and
a transverse channel is formed on a stator housing axial side, in which channel the two sloshing channels open, and the transverse channel connects the two sloshing channels to one another.

Assignees

• Audi Ag

Inventors

• Weber Andreas
• Greiter Ivo
• Gloede Harald
• Tschentscher Herbert
• Roethlingshoefer Frank

Classifications

• H02K9/193

  with provision for replenishing the cooling medium; with means for preventing leakage of the cooling medium · CPC title

• H02K7/116

  with gears · CPC title

• B60K11/02

  with liquid cooling · CPC title

• H02K1/32

  with channels or ducts for flow of cooling medium · CPC title

• H02K9/197

  in which the rotor or stator space is fluid-tight, e.g. to provide for different cooling media for rotor and stator · CPC title