US 7,520,191 B2
Actuator
Shigekazu Nagai, Adachi-ku (Japan); Akio Saitoh, Kawaguchi (Japan); and Masaki Imamura, Moriya (Japan)
Assigned to SMC Kabushiki Kaisha, Tokyo (Japan)
Filed on Nov. 17, 2004, as Appl. No. 10/989,638.
Claims priority of application No. 2003-392744 (JP), filed on Nov. 21, 2003.
Prior Publication US 2005/0109139 A1, May 26, 2005
Int. Cl. F16H 29/02 (2006.01)
U.S. Cl. 74—89.33  [92/165 PR; 92/172] 8 Claims
OG exemplary drawing
 
1. An actuator comprising:
a frame;
a plurality of sliding grooves formed in said frame;
a driving source arranged for said frame;
a driving force-transmitting mechanism for transmitting a driving force of said driving source;
a slider that makes reciprocating motion in an axial direction of said frame on the basis of said driving force transmitted from said driving force-transmitting mechanism;
a plurality of installation grooves identical in number to said plurality of sliding grooves, said installation grooves being formed on an outer wall surface of said slider opposing said plurality of sliding grooves, respectively, said installation grooves and said sliding grooves having the same radius of curvature; and
a guide mechanism comprising a plurality of resin sliding members disposed both in said sliding grooves and in said installation grooves and being interposed between an outer wall surface of said slider and an inner wall surface of said frame, said resin sliding members being fixed to said frame and/or said slider and being slidable in at least one of said installation grooves and said sliding grooves, wherein said resin sliding members guide said slider when said slider is displaced along said frame,
said plurality of resin sliding members comprising:
a pair of first resin sliding members installed in a pair of first installation grooves formed on said slider and which make sliding movement along first sliding grooves formed on a bottom wall section of said frame;
a pair of second resin sliding members installed in a pair of second installation grooves formed on said slider and which make sliding movement along second sliding grooves formed on side wall sections of said frame; and
a pair of third resin sliding members installed in a pair of third installation grooves formed on said slider and which make sliding movement along third sliding grooves formed on said side wall sections of said frame,
wherein each of said pairs of first resin sliding members has an axial center disposed on a inner virtual circle that is disposed concentrically inwardly by a predetermined distance with respect to an outer virtual circle, wherein said outer virtual circle intersects axial centers of said pairs of second and third resin sliding members.