Twin tube damper with remote gas reservoir
View Patent ↗A damper is provided having a twin tube construction interconnected to a gas reservoir. The connection of each of the inner and outer volumes of the twin tube to the gas reservoir is independently valved, and each of these valves are independently settable to change the differential pressure thereacross at which they open. The damper provides flow passages directly from the inner and outer volumes to enable flow form the compression to rebound sides thereof, as well as through the valved connections to the gas reservoir and at least one valved opening in the damper piston.
1. A fluid damper comprising:
an inner tube forming an inner fluid volume;
an outer tube forming an outer fluid volume;
a plurality of flow passages extending through said inner tube to enable fluid communication between said inner fluid volume and said outer fluid volume;
a remote reservoir in fluid communication with said inner fluid volume and said outer fluid volume, said remote reservoir comprising:
a fluid portion;
a gas portion; and
a floating piston separating said fluid portion and said gas portion;
a valved interconnection fluidically coupling said remote reservoir with said inner fluid volume and said outer fluid volume, said valved interconnection comprising:
a first flow passage extending between said inner fluid volume and said fluid portion of said remote reservoir;
a second flow passage extending between said outer fluid volume and said fluid portion of said remote reservoir; and
at least one valve interposed in at least one of said first flow passage and said second flow passage, wherein said at least one valve controls fluid flow through said at least one of said first flow passage and said second flow passage; and
a damping piston moveable within said inner tube and connected to a shaft extending outwardly of said inner tube through a sealed end thereof, movement of said damping piston enabling fluid to flow between one side of said damping piston and said fluid portion of said remote reservoir via said valved interconnection and at least one of said inner fluid volume and said outer fluid volume, said damping piston having at least one piston opening formed therethrough to enable said fluid to flow directly through said damping piston, and wherein said damping piston sealingly isolates said inner tube into a compression volume and a rebound volume, wherein said rebound volume is in continuous fluid communication with said outer fluid volume of said outer tube.
2. The fluid damper of claim 1 , wherein said outer fluid volume is an annular volume extending around said inner fluid volume.
3. The fluid damper of claim 2 , wherein, upon reaching of a threshold of a difference in fluid pressure across said at least one valve in at least one of said first flow passage and said second flow passage, causes an opening of said at least one valve to allow fluid flow therethrough.
4. The fluid damper of claim 3 , wherein a level of said threshold of said difference in said fluid pressure across said at least one valve is adjustable.
5. The fluid damper of claim 3 , wherein a level of said threshold of said difference in said fluid pressure of said at least one valve in said first flow passage is independently adjustable with respect to a level of said threshold difference in said fluid pressure of said at least one valve in said second flow passage.
6. The fluid damper of claim 4 , wherein said at least one valve comprises:
a through hole extending therethrough, and a bendable shim extending across said opening, wherein a bending of said bendable shim away from said opening enables opening of said fluid passage to flow therethrough; and
a spring plate biased by a spring to selectively press against said shim to urge said shim in a direction to close said opening of said valve of said at least one valve.
7. The fluid damper of claim 6 , wherein said inner tube comprises:
said plurality of flow passages spaced in a direction of travel of said damping piston therein and extending between said inner fluid volume and said outer fluid volume, said plurality of flow passages being in an annular wall of said inner tube, and said movement of said position of said damping piston therein exposes different ones of said plurality of flow passages to said fluid volume of said inner tube on either side of said damping piston such that movement of said damping piston enables fluid to flow from said first side of said damping piston to said second side of said damping piston via said plurality of flow passages.
8. The fluid damper of claim 7 , wherein at least a first opening and a second opening of said plurality of flow passages in said inner tube are spaced part, in a direction of said damping piston travel, by a gap greater than a width of said damping piston.
9. The fluid damper of claim 1 wherein said at least one valve is automated.
10. The fluid damper of claim 9 said at least one valve is remotely adjustable while a vehicle, to which said fluid damper is coupled, is in motion.