Roll control devices

1. A roll control device comprising:

at least first and second actuators that each have first and second chambers, and each of the first and second actuators having a first inlet port to the first chamber and a second inlet port to the second chamber;

at least one pump including at least a first outlet port fluidly connected to the first inlet port to the first chamber and a second outlet port fluidly connected to the second inlet port to the second chamber, and wherein the first outlet port is fluidly connected to a first valve and the second outlet port fluid connected to a second valve, the first and second valves being fluidly connected to a reservoir;

at least one failsafe valve downstream of the pump and upstream of the actuator;

at least first and second pressure relief valves associated with the first and second outlet ports of the pump and associated with the first and second inlet ports of the first actuator, and wherein the first and second pressure relief valves are positioned downstream of the failsafe valve and upstream of the first actuator;

at least third and fourth pressure relief valves associated with the first and second outlet ports of the pump and associated with the first and second chambers of the second actuator;

at least a first cross-link valve that fluidly connects the first and second chambers of the first actuator and a second cross-link valve that fluidly connects the first and second chambers of the second actuator;

at least one motor connected to the pump; and

a controller configured to command the motor to drive the pump and to control the failsafe and the first and second cross-link valves to transfer fluid between the first and second chambers of the first actuator and between the first and second chambers of the second actuator to change differential roll force associated with at least one of the first and second chambers to achieve a desired roll stability condition.

2. The roll control device according to claim 1 wherein the at least one pump comprises at least first and second pumps, and the at least one motor comprises first and second motors, and wherein the first motor drives the first pump to vary fluid flow within the first actuator and the second motor independently drives the second pump to vary fluid flow within the second actuator.

3. The roll control device according to claim 2 wherein the controller comprises a common controller that controls operation of the first and second motors and the first and second pumps.

4. The roll control device according to claim 2 wherein the first motor, the first pump and the first actuator are used to control roll stability for a first axle, and wherein the second motor, the second pump, and the second actuator are used to independently control roll stability for a second axle.

5. The roll control device according to claim 2 wherein the first and second pumps are each a bidirectional pump having first and second outlet ports respectively in fluid communication with first and second chambers of the respective first and second actuators, and wherein the controller commands the first and second motors to drive the first and second pumps in a desired direction.

6. The roll control device according to claim 2 comprising a first stabilizer connected to the first actuator and a second stabilizer connected to the second actuator and wherein roll characteristics are independently controlled between the first and second stabilizers.

7. The roll control device according to claim 6 wherein the first stabilizer comprises a first bar connected between a first pair of laterally spaced wheels and the second stabilizer comprises a second bar connected between a second pair of laterally spaced wheels.

8. The roll control device according to claim 1 wherein the at least one pump comprises only one pump, the at least one motor comprises only one motor, and wherein the motor drives the pump to vary fluid flow within the first actuator and the second actuator.

9. The roll control device according to claim 8 wherein the first and the second chambers of the first and second actuators are each respectively in fluid communication with the first and second outlet ports of the pump.

10. The roll control device according to claim 9 wherein the failsafe valve is in communication with the pump and acts to prevent transfer of fluid between first and second chambers of the first actuator in response to a failsafe condition, and wherein the second actuator is in communication with the pump upstream of the failsafe valve.

11. The roll control device according to claim 8 wherein the motor, the pump and the first actuator are used to control roll for a first axle, and wherein the motor, the pump, and the second actuator are used to independently control roll for a second axle.

12. The roll control device according to claim 8 wherein the pump is a single channel bidirectional pump having the first and second outlet ports respectively in fluid communication with the first and second chambers of the first actuator, and respectively in fluid communication with first and second chambers of the second actuator, and wherein the controller commands the motor to drive the pump in a desired direction.

13. The roll control device according to claim 8 comprising a first stabilizer connected to the first actuator and a second stabilizer connected to the second actuator and wherein roll characteristics are independently controlled between the first and second stabilizers.

14. The roll control device according to claim 1 including a second motor driving a second pump to control the second actuator, and including a second failsafe valve positioned downstream of the second pump and upstream of the third and fourth pressure relief valves.

15. A roll control device comprising:

at least first and second actuators each having first and second chambers;

a first cross-link valve in communication with first and second chambers in the first actuator and a second cross-link valve in communication with first and second chambers in the second actuator;

at least first and second pumps, wherein the first pump is fluidly connected between the first and second chambers of the first actuator and the second pump is fluidly connected between the first and second chambers of the second actuator;

a first failsafe valve positioned upstream of the first actuator and downstream of the first pump and a second failsafe valve positioned upstream of the second actuator and downstream of the second pump, and wherein the first failsafe valve is in communication with the first pump and acts to prevent transfer of fluid between first and second chambers of the first actuator in response to a failsafe condition, and wherein the second failsafe valve is in communication with the second pump and acts to prevent transfer of fluid between first and second chambers of the second actuator in response to a failsafe condition;

at least first and second motors respectively connected to the first and second pumps wherein the first motor drives the first pump to vary fluid flow within the first actuator and the second motor independently drives the second pump to vary fluid flow within the second actuator; and

a controller configured to command the motor to drive the pump in response to a desired roll stability signal for transferring fluid between the first and second chambers to change differential roll force associated with at least one of the first and second chambers.

16. The roll control device according to claim 15 wherein the first and second failsafe valves are normally closed, the first cross-link valve is normally closed, and the second cross-link valve is normally open.

17. A roll control device comprising:

at least first and second actuators each having first and second chambers, and wherein each first chamber has a first inlet port and each second chamber has a second inlet port;

only one pump that includes at least a first outlet port fluidly connected to the first inlet ports of the first and second actuators and a second outlet port fluidly connected to the second inlet ports of the first and second actuators;

at least one failsafe valve downstream of the pump and upstream of the first actuator, the failsafe valve being in communication with the pump and acting to prevent transfer of fluid between the first and second chambers of the first actuator in response to a failsafe condition, and wherein the second actuator is in communication with the pump upstream of the failsafe valve;

a first cross-link valve that fluidly connects the first and second chambers of the first actuator;

a second cross-link valve that fluidly connects the first and second chambers of the second actuator, and wherein the failsafe valve is normally closed, the first cross-link valve is normally closed, and the second cross-link valve is normally open;

only one motor connected to the pump to drive the pump to vary flow within the first and second actuators; and

a controller configured to command the motor to drive the pump and to control the failsafe and cross-link valves to transfer fluid between the first and second chambers to change differential roll force associated with at least one of the first and second chambers to achieve a desired roll stability condition.