Composite fluid actuated cylinder
View Patent ↗A fluid actuator having a honed metallic sleeved inner liner assembled with fitted end caps. The inner liner and end caps are wound with carbon reinforced fiber filaments in both longitudinal and hoop orientations so as to withstand increased fluid pressure over traditional metallic designs. The fluid actuator of the present invention is lightweight and had an extremely stiff piston and rod assembly, which may also be fabricated from high flexural modulus composite materials so as to allow for a very stiff, lightweight, hydraulic cylinder which is particularly resistant to column buckling at long extensions and comprises an economical, non-rebuildable design.
1. A fluid actuator, comprising:
a fiber reinforced composite cylinder assembly;
a piston disposed in the fiber reinforced composite cylinder assembly;
a fiber reinforced composite rod connected to the piston and extending through an end of the cylinder assembly, the rod being rigid and comprising longitudinally oriented fibers to enhance buckling resistance in the longitudinal direction,
wherein the fiber reinforced composite cylinder assembly includes fiber reinforcement along the cylinder body and end caps forming a substantially permanently assembled fluid actuator.
2. A fluid actuator according to claim 1 , wherein the piston comprises a fiber reinforced composite.
3. A fluid actuator according to claim 2 , further comprising a hardened metallic coating disposed over the piston.
4. A fluid actuator according to claim 2 , wherein the fiber reinforced composite piston and fiber reinforced composite rod comprise a single-piece integral unit.
5. A fluid actuator according to claim 4 wherein the fiber reinforced composite rod and fiber reinforced composite piston comprises a carbon fiber molded structure.
6. A fluid actuator according to claim 4 , further comprising a hardened metallic coating disposed over the fiber reinforced composite piston and rod.
7. A fluid actuator according to claim 1 , wherein the piston is adhesively connected to the fiber reinforced composite rod.
8. A fluid actuator according to claim 1 , wherein the fiber reinforced composite cylinder assembly further comprises:
a metal liner;
first and second end fittings attached to ends of the metal liner;
a carbon fiber impregnated with an epoxy resin wound about the metal liner and end fittings.
9. A fluid actuator according to claim 8 , wherein the carbon fiber is layered in helical and hoop windings.
10. A fluid actuator according to claim 8 wherein the first and second end fittings overlap associated end portions of the metal liner and comprise external domed surfaces.
11. A fluid actuator according to claim 1 , wherein the fiber reinforced composite cylinder assembly further comprises:
a liner;
first and second end fittings attached to ends of the liner;
helical and hoop windings about the liner and first and second end fittings as a single unit.
12. A hydraulic actuator, comprising:
a mandrel, the mandrel comprising:
a hollow tube including a hardened metallic interior cylindrical surface;
semi-spherical end caps disposed at each end of the hollow tube;
carbon fiber wound about the mandrel and reinforcing the hollow tube and semi-spherical end caps of the mandrel;
a piston and rod assembly comprising carbon fiber reinforcement disposed in the hollow tube, wherein the rod comprises a carbon fiber composite having longitudinally oriented fibers.
13. A hydraulic actuator according to claim 12 , wherein the piston and rod are adhesively attached to one another.
14. A hydraulic actuator according to claim 12 , wherein the piston and rod comprise a single, integrated piece.
15. A hydraulic actuator according to claim 14 , wherein the piston and rod comprise a carbon fiber mold.
16. A hydraulic actuator according to claim 12 , further comprising a hardened metallic coating disposed over the piston.
17. An assembly, comprising:
a piston having a central cavity;
a rod inserted into the central cavity, wherein the rod comprises a carbon fiber composite having longitudinally oriented fibers; and
an adhesive disposed in an annulus between the central cavity and the rod.
18. An assembly according to claim 17 , wherein the adhesive comprises an epoxy.
19. An assembly according to claim 17 , wherein the piston comprises a carbon composite and a hardened metallic over layer.
20. A method of making a hydraulic cylinder, comprising:
providing a cylinder;
inserting a fiber reinforced composite piston and rod into the cylinder, wherein the rod comprises a carbon fiber composite having longitudinally oriented fibers; and
winding filament around the cylinder to reinforce substantially all of the surface area of the cylinder and enclose the piston and rod within the cylinder.
21. A method of making a hydraulic cylinder according to claim 20 , wherein the cylinder comprises a metallic liner.
22. A method of making a hydraulic cylinder according to claim 21 , further comprising attaching end caps to ends of the metallic liner, and wherein the winding comprises winding the end caps and the cylinder as a single unit.
23. A method of making a hydraulic cylinder according to claim 20 , further comprising adhesively bonding the piston to the rod.
24. A method of making a hydraulic cylinder according to claim 20 , further comprising molding the fiber reinforced composite piston and rod as a unitary piece.
25. A method of making a hydraulic cylinder according to claim 20 , further comprising overlaying the piston with a hardened metallic coating.