Hydraulic damper, hydraulic bump-stop and diverter valve
View Patent ↗Hydraulic bump stops and bi-directional diverter valves may be used to protect hydraulic systems, including, for example in one embodiment, the hydraulic actuators of an active suspension system, from damage due to operation outside the normal operating range of the system. In some embodiments, a hydraulic bump stop may be used to slow down the motion of a piston at the extremes of the compression and/or extension strokes of an actuator. In another embodiment, a diverter valve may be used to protect a hydraulic motor/pump in a hydraulic system from an over-speed condition. When the piston in an active suspension system actuator moves at a speed in excess of a threshold value, one or more diverter valves may be used to divert flow away from the hydraulic motor/pump. In some embodiments, a diverter valve may be a dual or single spool bi-directional diverter valve.
1. A bi-directional hydraulic diverter valve, comprising:
a first spool biased towards a first closed position;
a second spool biased towards a second closed position;
a first fluid flow path through the diverter valve; and
a second fluid flow path through the diverter valve;
a first bypass fluid flow path through the diverter valve;
a second bypass fluid flow path through the diverter valve;
wherein at a first operating point, wherein fluid flow in the first fluid flow path, in at least one mode of operation, causes the first spool to be displaced such that at least some of the fluid flowing in the first fluid flow path is diverted to the first bypass fluid flow path.
2. The bi-directional hydraulic diverter valve of claim 1 , wherein at a second operating point fluid flow in the second flow path causes the second spool to be displaced such that at least some of the fluid flowing in the second fluid flow path is diverted to the second bypass fluid flow path.
3. The bi-directional hydraulic diverter valve of claim 2 , wherein the first bypass fluid flow path and the second bypass fluid flow path are distinct flow paths.
4. The bi-directional hydraulic diverter valve of claim 2 , further comprising at least one of a wave spring and a coil spring that biases the first spool to the first closed position.
5. The bi-directional hydraulic diverter valve of claim 4 , wherein the at least one of the wave spring and the coil spring also biases the second spool to the second closed position.
6. The bi-directional hydraulic diverter valve of claim 1 , wherein the first spool and the second spool are constrained to move axially.
7. The bi-directional hydraulic diverter valve of claim 1 , wherein the first spool is biased against the second spool to bias the second spool towards the second closed position.
8. A bi-directional hydraulic diverter valve, comprising:
a first fluid flow path through the diverter valve;
a second fluid flow path through the diverter valve;
at least one spool biased toward a closed position; and
at least one bypass flow path through the diverter valve;
wherein at a first operating point, fluid flow in the first fluid flow path produces a force on the at least one spool that displaces the at least one spool such that at least some of the fluid flowing in the first fluid flow path is diverted to the at least one bypass flow path.
9. The bi-directional hydraulic diverter valve of claim 8 , wherein the at least one spool valve includes a first spool valve and a second spool and the at least one bypass flow path through the diverter valve includes a first bypass flow path through the diverter valve and a second bypass flow path through the diverter valve, wherein at a second operating point fluid flow in the second fluid flow path produces a force on the second spool that at least displaces the second spool such that at least some of the fluid flowing in the second fluid flow path is diverted to the second bypass flow path.
10. The bi-directional hydraulic diverter valve of claim 9 , wherein the first bypass flow path and the second bypass flow path are distinct flow paths.
11. The bi-directional hydraulic diverter valve of claim 8 , further comprising at least one of a wave spring and a coil spring that biases the at least one spool toward the closed position.
12. A method of operating a diverter valve, comprising:
displacing a first spool valve biased towards a first closed position in response to fluid flowing through a first flow path in the diverter valve such that at least some of the fluid flowing through the first flow path is diverted to a first bypass flow path; and
displacing a second spool valve biased towards a second closed position in response to fluid flowing through a second flow path in the diverter valve such that at least some of the fluid flowing through the second flow path is diverted to a second bypass flow path.
13. The method of claim 12 , wherein the first spool and the second spool form an integral unit.
14. The method of claim 13 , wherein the first bypass fluid flow path and the second bypass fluid flow path are distinct flow paths.
15. The method of claim 13 , further comprising biasing the first spool against the second spool to bias the second spool towards the second closed position.