IP Library › Granted Patent US 12663069

Granted Patent B2

US 12663069 · App. 18/775,637 · Granted Jun 23, 2026

Use of dynamic pressure to control fluid bleed system

Inventors: Christopher Chapanar (Massillon, OH); Kyle Nelson (Delaware, OH); Antonio Eduardo Mogro Zambrano (Puebla, MX)

Assignee: Schaeffler Technologies AG & Co. KG

F16H57/0423 F16H57/0408 F16H57/0417

View Patent ↗

Loading inventors, assignments & file history…

Monitor This Case

Get email alerts when status or documents change.

Order Certified Copies

Most orders are placed with the USPTO same day — all within 24 business hours.

Order via The Patent Place →

Pre-filled with this patent's details

Quick Facts

Patent No.: US 12663069
App. No.: 18/775,637
Granted: Jun 23, 2026
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

A drive unit for an electric vehicle including a gearbox having rotating components supported in a gearbox portion of the housing, an oil circuit in fluid communication with the gearbox portion of the housing for circulating oil in response to dynamic pressure generated by the rotating components of the gearbox when in operation, and a bleed passage connecting the oil circuit to the gearbox portion of the housing. Dynamic pressure in the gearbox portion of the housing generated by the rotating components when in operation restricts flow of oil through the bleed passage from the oil circuit to the gearbox portion of the housing, and static pressure in the gearbox portion of the housing when the gearbox is not in operation permits flow of oil from the oil circuit to the gearbox portion of the housing.

Claims (41)

1 . A drive unit comprising:

a housing including a central portion and a gearbox portion separate from the central portion;

at least one of an electric motor or a heat exchanger supported in the central portion of the housing;

a gearbox having rotating components supported in a-the gearbox portion of the housing;

an oil circuit in fluid communication with the gearbox portion of the housing for circulating oil to and from at least one of the electric motor or the heat exchanger in the central portion of the housing in response to dynamic pressure generated by the rotating components of the gearbox when in operation; and

a bleed passage connecting the oil circuit in the central portion of the housing to the gearbox portion of the housing;

wherein dynamic pressure in the gearbox portion of the housing generated by the rotating components when in operation restricts flow of oil through the bleed passage from the oil circuit to the gearbox portion of the housing; and

wherein static pressure in the gearbox portion of the housing when the gearbox is not in operation permits flow of oil from the oil circuit to the gearbox portion of the housing.

2 . The drive unit according to claim 1 , wherein the gearbox portion of the housing includes a sump.

3 . The drive unit according to claim 2 , wherein the oil circuit is connected to the gearbox portion of the housing for the supply and return of oil above the sump and the bleed passage is connected to the sump.

4 . The drive unit according to claim 3 , wherein the central portion of the housing includes a sump.

5 . The drive unit according to claim 4 , wherein the bleed passage extends between the sump of the gearbox portion of the housing and the sump of the central portion of the housing.

6 . The drive unit according to claim 4 , further comprising at least one dynamic seal, wherein the bleed passage is below the at least one dynamic seal, whereby when the gearbox is not in operation, a fluid level in the sump of the gearbox portion of the housing and a fluid level in the sump of the central portion of the housing can equalize at a level below the at least one dynamic seal.

7 . The drive unit according to claim 4 , wherein the housing further comprises a drain port for draining oil from the sump of the gearbox portion of the housing, wherein the drain port is in fluid communication with the sump of the central portion of the housing via the bleed passage.

8 . The drive unit according to claim 3 , further comprising a gasket between the gearbox portion of the housing and the central portion of the housing, wherein the bleed passage comprises a hole in the gasket.

9 . A method of controlling flow of fluid in a hydraulic circuit of a drive unit comprising:

providing a drive unit having:

a housing including a central portion and a gearbox portion separate from the central portion;

at least one of an electric motor or a heat exchanger supported in the central portion of the housing;

a gearbox having rotating components supported in a gearbox portion of the housing;

a bleed passage connecting the oil circuit in the central portion of the housing to the gearbox portion of the housing; and

operating the rotating components of the gearbox to generate a dynamic pressure in the gearbox portion of the housing to restrict flow of oil through the bleed passage from the oil circuit to the gearbox portion of the housing.

10 . The method according to claim 9 , wherein the gearbox portion of the housing includes a sump.

11 . The method according to claim 10 , wherein the oil circuit is connected to the gearbox portion of the housing for the supply and return of oil above the sump and the bleed passage is connected to the sump.

12 . The method according to claim 9 , wherein the central portion of the housing includes a sump.

13 . The method according to claim 12 , wherein the bleed passage extends between the sump of the gearbox portion of the housing and the sump of the central portion of the housing.

14 . The method according to claim 12 , further comprising at least one dynamic seal, wherein the bleed passage is below the at least one dynamic seal, whereby when the gearbox is not in operation, a fluid level in the sump of the gearbox portion of the housing and a fluid level in the sump of the central portion of the housing can equalize at a level below the at least one dynamic seal.

15 . The method according to claim 12 , wherein the housing further comprises a drain port for draining oil from the sump of the gearbox portion of the housing, wherein the drain port is in fluid communication with the sump of the central portion of the housing via the bleed passage.

16 . The method according to claim 9 , further comprising a gasket between the gearbox portion of the housing and the central portion of the housing, wherein the bleed passage comprises a hole in the gasket.

17 . A drive unit comprising:

a housing;

a gearbox having rotating components supported in the gearbox portion of the housing;

an oil circuit in fluid communication with the gearbox portion of the housing for circulating oil in response to dynamic pressure generated by the rotating components of the gearbox when in operation; and

a bleed passage connecting the oil circuit to the gearbox portion of the housing;

wherein static pressure in the gearbox portion of the housing when the gearbox is not in operation permits flow of oil from the oil circuit to the gearbox portion of the housing;

wherein the gearbox portion of the housing includes a sump;

wherein the oil circuit is connected to the gearbox portion of the housing for the supply and return of oil above the sump and the bleed passage is connected to the sump;

wherein the housing includes a central portion containing at least one of a heat exchanger or a motor, and the oil circuit circulates oil through at least one of the heat exchanger or the motor; and

further comprising a gasket between the gearbox portion of the housing and the central portion of the housing, wherein the bleed passage comprises a hole in the gasket.