Rotary actuator and method for forming a rotary piston
AssigneeKeystone International Holdings Corp.
InventorWilliam B. Scobie
Life of this patent
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Abstract
Improved techniques are provided for manufacturing a toroidal arc segment piston for use in a fluid pressure responsive rotary actuator, and for forming an actuator housing defining an arcuate chamber for receiving a rotary actuator piston. A moldable polymeric material is positioned within an arcuate master chamber in a piston-forming fixture, and a metal piston core is rotatably mounted to the fixture. The piston core is rotated to displace the polymeric material and form a sheath about the piston core. After curing, the piston core and sheath are rotated out of the arcuate master chamber, and are installed in a rotary actuator housing. A master piston may similarly be used to form a polymeric lining which defines the chamber for receiving the piston in the actuator housing.
Claims20
A method of forming a toroidal arc segment piston for use in a rotary actuator including a housing defining an arcuate chamber therein, an actuator shaft journaled within the housing and rotatable in response to movement of the piston, a fluid inlet to introduce pressurized fluid into the housing to effect movement of the piston, and a seal for dynamic sealing engagement between the housing and the piston, the method comprising:
- (a) forming a fixture defining an arcuate master chamber therein having a toroidal arc segment configuration;
- (b) inserting a moldable polymeric material within the arcuate master chamber;
- (c) rotatably mounting a metal piston core with respect to the fixture;
- (d) rotating the metal piston core into the arcuate master chamber to form a sheath about the metal piston core filled with the polymeric material;
- (e) curing the moldable polymeric material sheath about the metal piston core;
- and
- (f) thereafter rotating the metal piston core and the cured polymeric sheath out of the master piston chamber within the fixture.
A rotary actuator, comprising:
- a housing defining an arcuate chamber therein;
- a toroidal arc segment piston disposed within the housing for reciprocable movement within the arcuate chamber, the piston including a metal core and an outer polymeric material sheath;
- a fluid inlet to introduce pressurized fluid into the housing to effect movement of the piston in a first direction;
- return means to effect movement of the piston in an opposing second direction;
- a shaft journaled within the housing;
- an arm interconnecting the metal core and the shaft such that the shaft is rotated in response to movement of the piston;
- and
- a seal for effecting dynamic sealing between the outer polymeric material sheath and the housing.
A method of forming a rotary actuator housing for a rotary actuator including an actuator piston movable within the housing in response to the fluid pressure for rotating an actuator shaft interconnected with the piston, the method comprising:
- forming a housing having a generally arcuate chamber therein;
- rotatably mounting a master piston with respect to the housing;
- inserting a moldable polymeric material within the arcuate chamber;
- rotating the master piston into the arcuate chamber to form an annular sheath between the master piston and the generally arcuate chamber for the polymeric material;
- thereafter rotating the master piston out of the housing to form a chamber having a toroidal arc segment configuration defined by the curved polymeric material for receiving the actuator piston;
- and
- removing the master piston from the housing.
Dependencies are inferred from the claim text.