Single axle roll control system with gerotor pump

Patent metadata

Field	Value
Publication number	US-12358335-B2
Application number	US-202318324486-A
Country	US
Kind code	B2
Filing date	May 26, 2023
Priority date	May 15, 2023
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

A single axle suspension system including right and left dampers, first and second hydraulic circuits, a first pressurizing mechanism connected in fluid communication with the first and second hydraulic circuits, and a second pressurizing mechanism connected in series with the first pressurizing mechanism. The first pressurizing mechanism is a gerotor pump that provides roll control by generating a pressure differential between the first and second hydraulic circuits, which increases fluid pressure inside either the first working chamber of the right damper and the second working chamber of the left damper or inside the first working chamber of the left damper and the second working chambers of the right damper to provide roll stiffness that counters vehicle roll during cornering. The second pressurizing mechanism adjusts static pressure within the first and second hydraulic circuits by adding and removing hydraulic fluid to and from the first and second hydraulic circuits.

First claim

What is claimed is:

1. A single axle suspension system, comprising:
right and left dampers each including a damper housing, a piston rod, and a piston that is mounted on the piston rod and arranged in sliding engagement inside the damper housing such that the piston divides the damper housing into first and second working chambers;
a first hydraulic circuit connecting the first working chamber of the right damper and the second working chamber of the left damper;
a second hydraulic circuit connecting the second working chamber of the right damper and the first working chamber of the left damper;
a first pressurizing mechanism that is connected in fluid communication with the first and second hydraulic circuits and configured to adjust roll resistance of the single axle suspension system by generating a pressure differential between the first and second hydraulic circuits independent of damper movements; and
a second pressurizing mechanism that is connected in series with the first pressurizing mechanism and configured to adjust static pressure within the first and second hydraulic circuits by adding and removing hydraulic fluid to and from the first and second hydraulic circuits,
wherein the first pressurizing mechanism is a gerotor pump that includes a first port that is arranged in fluid communication with the first hydraulic circuit, a second port that is arranged in fluid communication with the second hydraulic circuit, and a third port that is arranged in fluid communication with the second pressurizing mechanism.

2. The single axle suspension system set forth in claim 1 , wherein the gerotor pump has a first cavity that is arranged in fluid communication with the first port, a second cavity that is arranged in fluid communication with the second port, and a gerotor gear assembly that is rotatably driven.

3. The single axle suspension system set forth in claim 2 , wherein the gerotor pump has a third cavity that is arranged in fluid communication with the third port via a channel, wherein the gerotor pump is configured so that hydraulic fluid is permitted to flow from the third cavity to the first cavity when fluid pressure in the third cavity is greater than fluid pressure in the first cavity, and wherein the gerotor pump is configured so that hydraulic fluid is permitted to flow from the third cavity to the second cavity when fluid pressure in the third cavity is greater than fluid pressure in the second cavity.

4. The single axle suspension system set forth in claim 3 , wherein the gerotor pump has an electric motor that is configured to drive the gerotor gear assembly in a first working mode where rotation of the electric motor in a first rotational direction causes the gerotor pump to pump hydraulic fluid from the first cavity to the second cavity such that fluid pressure in the second cavity rises above fluid pressure in the first cavity and such that the first port acts as an inlet and the second port acts as an outlet of the gerotor pump and wherein the electric motor is configured to drive the gerotor gear assembly in a second working mode where rotation of the electric motor in a second rotational direction causes the gerotor pump to pump hydraulic fluid from the second cavity to the first cavity such that fluid pressure in the first cavity rises above fluid pressure in the second cavity and such that the second port acts as the inlet and the first port acts as the outlet of the gerotor pump.

5. The single axle suspension system set forth in claim 3 , wherein hydraulic fluid in the third cavity of the gerotor pump is separated from hydraulic fluid in the first and second cavities of the gerotor pump by check valves and wherein the check valves are configured to permit hydraulic fluid to flow from the third cavity to the first cavity when fluid pressure in the third cavity is greater than fluid pressure in the first cavity and permit hydraulic fluid to flow from the third cavity to the second cavity when fluid pressure in the third cavity is greater than fluid pressure in the second cavity.

6. The single axle suspension system set forth in claim 3 , wherein the third cavity of the gerotor pump is arranged in fluid communication with the first and second cavities of the gerotor pump via restrictive passages or orifices that have a low cross-sectional flow area relative to the first and second cavities such that three distinct zones of fluid pressure are maintained within the first, second, and third cavities during operation of the gerotor pump.

7. The single axle suspension system set forth in claim 2 , wherein the gerotor gear assembly is disposed within a pocket in the gerotor pump, the gerotor gear assembly includes inner rotor and an outer rotor, wherein spaces between the inner and outer rotors define fluid pumping chambers that are arranged in fluid communication with the first and second cavities of the gerotor pump, and wherein the inner rotor rotates about an axis of rotation that is offset from an axis of rotation of the outer rotor such that the fluid pumping chambers change in size when the inner and outer rotors rotate.

8. The single axle suspension system set forth in claim 1 , further comprising:
first and second bi-directional conduits that extend between and interconnect the first and second ports of the first pressurizing mechanism with the first and second hydraulic circuits;
a hydraulic line that extend between and interconnects the third port of the first pressurizing mechanism with the second pressurizing mechanism.

9. The single axle suspension system set forth in claim 8 , wherein the second pressurizing mechanism has a variable volume chamber with a driven piston that is moveable in first and second directions to increase and decrease the volume of the variable volume chamber.

10. The single axle suspension system set forth in claim 9 , wherein movement of the driven piston of the second pressurizing mechanism in the first direction decreases the volume in the variable volume chamber of the second pressurizing mechanism and pushes the hydraulic fluid out of the variable volume chamber of the second pressurizing mechanism and into the hydraulic line between the first and second pressurizing mechanisms to cause an increase in the static pressure in the system and wherein movement of the driven piston of the second pressurizing mechanism in the second direction increases the volume in the variable volume chamber of the second pressurizing mechanism and draws the hydraulic fluid into the variable volume chamber of the second pressurizing mechanism from the hydraulic line between the first and second pressurizing mechanisms to cause a decrease in the static pressure of the system.

11. The single axle suspension system set forth in claim 10 , wherein the second pressurizing mechanism includes a ball/screw mechanism that is configured to operably drive movement of the driven piston in the first and second directions.

12. The single axle suspension system set forth in claim 8 , wherein the second pressurizing mechanism is a bi-directional pump that is connected in fluid communication with a reservoir, wherein the bi-directional pump of the second pressurizing mechanism is configured to pump hydraulic fluid in a first direction from the reservoir and into the hydraulic line between the first and second pressurizing mechanisms to cause an increase in the static pressure in the system, and wherein the bi-directional pump of the second pressurizing mechanism is configured to pump hydraulic fluid in a second direction from the hydraulic line between the first and second pressurizing mechanisms and into the reservoir to cause a decrease in the static pressure of the

Assignees

• Driv Automotive Inc
• Advanced Suspension Tech Llc

Inventors

• Dhaens Miguel
• Al Sakka Monzer

Classifications

• B60G2500/114

  pressure regulating valves · CPC title

• B60G2202/416

  using a pump, e.g. in the line connecting the lower chamber to the upper chamber of the actuator · CPC title

• B60G21/073 Primary

  between wheels on the same axle but on different sides of the vehicle, i.e. the left and right wheel suspensions being interconnected · CPC title

• B60G13/08

  hydraulic · CPC title

• B60G17/0162

  mainly during a motion involving steering operation, e.g. cornering, overtaking (B60G17/0164 takes precedence) · CPC title