Actuator system

Patent metadata

Field	Value
Publication number	US-11084350-B2
Application number	US-201816133827-A
Country	US
Kind code	B2
Filing date	Sep 18, 2018
Priority date	Sep 19, 2017
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

Abstract

An actuator system for a vehicle suspension system including: an actuator having a piston and a first fluid chamber separated from a second fluid chamber by the piston; a hydraulic pump having a first port, a first hydraulic circuit operable to connect the first port to the first chamber, the first hydraulic circuit including a first valve, the first valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the first chamber; a first hydraulic accumulator connected to a first gallery of the first hydraulic circuit between the first port and the first valve; a second hydraulic accumulator connected to a second port of the pump via a second gallery; and a second valve, the second valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the first gallery to the second gallery.

First claim

The invention claimed is:

1. An actuator system for a vehicle suspension system comprising:
an actuator having a piston and a first fluid chamber separated from a second fluid chamber by the piston;
a hydraulic pump having a first port;
a first hydraulic circuit operable to connect the first port to the first chamber, the first hydraulic circuit including a first valve, the first valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the first chamber;
a first hydraulic accumulator connected to a first gallery of the first hydraulic circuit between the first port and the first valve;
a second hydraulic accumulator connected to a second port of the pump via a second gallery;
a second valve, the second valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the first gallery to the second gallery;
a second hydraulic circuit operable to connect the first port to the second chamber, the second hydraulic circuit including a third valve, the third valve being a damper valve operable to variably restrict flow of hydraulic fluid out of the second chamber;
a third hydraulic accumulator connected to a third gallery of the second hydraulic circuit between the first port and the third valve; and
a fourth valve, the fourth valve being a variable pressure relief valve operable to variably restrict flow of hydraulic fluid from the third gallery to the second gallery.

2. The actuator system of claim 1 , wherein the first port is selectively connectable to the first gallery via a selection valve, the selection valve being operable to isolate the first port from the first gallery.

3. The actuator system of claim 1 , wherein the actuator has a full stroke differential volume defined by a difference between a full stroke volume of the first chamber and a full stroke volume of the second chamber and the second accumulator is sized to receive all of the full stroke differential volume.

4. The actuator system of claim 3 , wherein the fourth valve includes a valve operable to allow the flow of hydraulic fluid from the second gallery to the third gallery but prevent flow of hydraulic fluid from the third gallery to the second gallery.

5. The actuator system of claim 1 , wherein the first port is selectively connectable to the first gallery via a selection valve, the selection valve being operable to isolate the first port from the first gallery, wherein the first port is selectively connectable to the first hydraulic circuit and/or the second hydraulic circuit via the selection valve, the selection valve being operable to simultaneously connect the first port to the first hydraulic circuit and the second hydraulic circuit, or isolate the first port from the first hydraulic circuit while connecting the first port to the second hydraulic circuit, or isolate the first port from the second hydraulic circuit while connecting the first port to the first hydraulic circuit.

6. The actuator system of claim 5 the selection valve is a variable valve.

7. The actuator system of claim 1 including a valve operable to allow flow of hydraulic fluid from the second gallery to the first gallery but prevent flow of hydraulic fluid from the first gallery to the second gallery.

8. A vehicle including a ground engaging structure mounted on a suspension system attached to a vehicle body thereby defining a sprung mass and an unsprung mass, the vehicle including the actuator system as defined in claim 1 acting at least partially to support the sprung mass on the unsprung mass,
wherein one or more or all of the first valve, second valve, first accumulator, and second accumulator define at least a part of the unsprung mass, and/or
wherein the pump defines at least a part of the sprung mass.

9. The vehicle of claim 8 , wherein the first port of the actuator system is selectively connectable to the first gallery via a selection valve, the selection valve being operable to isolate the first port from the first gallery, the selection valve defining at least a part of the unsprung mass.

10. The vehicle of claim 8 , wherein one or more or all of the third valve, fourth valve, and third accumulator define at least a part of the unsprung mass.

11. The vehicle of claim 10 wherein the second hydraulic circuit has a second hydraulic circuit sprung portion defining the sprung mass and a second hydraulic circuit unsprung portion defining the unsprung mass and a second hydraulic circuit single flexible hydraulic line connecting the second hydraulic circuit sprung portion to the second hydraulic circuit unsprung portion, the second hydraulic circuit single flexible hydraulic line having a first end defining the sprung mass and a second end defining the unsprung mass.

12. The vehicle of claim 8 wherein the first hydraulic circuit has a first hydraulic circuit sprung portion defining the sprung mass and a first hydraulic circuit unsprung portion defining the unsprung mass and a first hydraulic circuit single flexible hydraulic line connecting the first hydraulic circuit sprung portion to the first hydraulic circuit unsprung portion, the first hydraulic circuit single flexible hydraulic line having a first end defining a sprung mass and a second end defining an unsprung mass.

13. A method of operating the vehicle of claim 8 , the method including:
a) defining a first target pressure for the first chamber,
b) operating the pump to generate the first target pressure in the first chamber and the first accumulator,
c) setting the second valve relief pressure to a value dependent upon the first target pressure.

14. The method of claim 13 when during b) the pump pumps hydraulic fluid from the second hydraulic circuit to the first hydraulic circuit.

15. The method of claim 13 , including subsequently:
d) defining a second target pressure for the second chamber,
e) operating the pump to generate the second target pressure in the second chamber, and the third accumulator,
f) setting the fourth valve relief pressure to a value dependent upon the second target pressure.

16. The method of claim 15 wherein during e) the pump pumps hydraulic fluid from the first hydraulic circuit to the second hydraulic circuit.

17. A vehicle including a ground engaging structure mounted on a suspension system attached to a vehicle body thereby defining a sprung mass and an unsprung mass, the vehicle including the actuator system as defined in claim 1 acting at least to partially support the sprung mass on the unsprung mass,
wherein one or both of the first valve and first accumulator define at least a part of the unsprung mass, and/or
wherein one or more or all of the second valve, second accumulator, and pump define at least a part of the sprung mass.

18. The vehicle of claim 17 , wherein the first port of the actuator system is selectively connectable to the first gallery via a selection valve, the selection valve being operable to isolate the first port from the first gallery, the selection valve defining at least a part of the sprung mass.

19. The vehicle of claim 17 , wherein one or both of the third valve and third accumulator define at least a part of the unsprung mass and/or
wherein the fourth valve defines at least part of the sprung mass.

Assignees

• Jaguar Land Rover Ltd

Inventors

• Birch Luke
• Brown Sam
• Neilson Robert
• Robertson James

Classifications

• B60G2500/10

  Damping action or damper · CPC title

• B60G17/0195

  characterised by the regulation being combined with other vehicle control systems {(conjoint control of vehicle sub-units including control of suspension systems B60W10/22)} · CPC title

• B60G2500/114

  pressure regulating valves · CPC title

• F16F9/46

  allowing control from a distance {, i.e. location of means for control input being remote from site of valves, e.g. on damper external wall (attachment of valve units to cylinders F16F9/325)} · CPC title

• F16F2228/066

  Variable stiffness · CPC title