Patent ID: 6571680
Filing Date: 2003-06-03
Classification: F01B,F15B

Abstract:
A pneumatic motor, comprising:a) a motor body having a main piston chamber with opposed first and second chamber ends, two spool chambers in fluid communication with said main piston chamber, an inlet for flowing a pressurized fluid into each of the two spool chambers, an outlet provided in the housing for exhausting the pressurized fluid from said main piston chamber and each of the two spool chambers, wherein each spool chamber has a respective spool member located therein; b) each spool member being adapted to be movable in a first direction to permit pressurized fluid to be supplied to said main piston chamber and also in a second direction to permit the pressurized fluid to be exhausted from said main piston chamber; and c) a piston member movable in a reciprocating manner in said main piston chamber in response to movement by said spool members within their spool chambers, said piston having i) a first piston end and a second piston end, said first and said second piston ends defining, with said first and said second chamber ends, a first chamber and a second chamber, respectively, in said main piston chamber during reciprocation of said piston; ii) an annular groove along an outer periphery of the piston member between said first and second piston ends, said groove defining a movable annular piston chamber located in said main piston chamber between said first and said second chamber ends; and iii) a first piston passage connecting said annular piston chamber to said first chamber and a second piston passage connecting said annular piston chamber to said second piston chamber wherein said piston passages are internal bores located within said piston; d) a first valve in said first piston passage and a second valve in said second piston passage, wherein said first and second valves are directional check valves that permit passage of air in only one direction into said annular piston chamber from said first and second chambers, respectively, such that while said piston reciprocates within said main piston chamber, said first valve and said second valve alternately exhaust said first and said second chambers into said annular piston chamber through first and second piston passages respectively, wherein said directional check valves comprise first and second â€œVâ€ -shaped grooves located circumferentially around said annular piston chamber and in fluid communication with said internal bores in said piston with first and second â€œOâ€ -rings seated in said â€œVâ€ -shaped grooves.