초록 ▼

An object of the present invention is to provide a compact motion conversion transmission apparatus which can set the transmission characteristic for motion or force as desired over a wide range. The apparatus includes input, intermediate, and output members which are fitted to one another while bei

An object of the present invention is to provide a compact motion conversion transmission apparatus which can set the transmission characteristic for motion or force as desired over a wide range. The apparatus includes input, intermediate, and output members which are fitted to one another while being aligned with an axis and move in relation to one another while being aligned with the axis. Further, the apparatus includes first transmission means which converts a first motion of the input member to a second motion and transmits the second motion to the intermediate member, the first motion being one of a rectilinear motion along the axis and a rotary motion about the axis, and the second motion being the other of the rectilinear motion along the axis and the rotary motion about the axis; and second transmission means which converts the second motion of the intermediate member to the first motion and transmits the first motion to the output member. At least one of the first transmission means and the second transmission means continuously and nonlinearly varies a ratio of an amount of motion of a motion transmission destination member to an amount of motion of a motion transmission source member according to the amount of motion of the motion transmission source member.

대표청구항 ▼

1. A motion conversion transmission apparatus comprising: an input member, an intermediate member, and an output member which are fitted to one another while being aligned with an axis and move in relation to one another while being aligned with the axis;a first transmission which converts a first m

1. A motion conversion transmission apparatus comprising: an input member, an intermediate member, and an output member which are fitted to one another while being aligned with an axis and move in relation to one another while being aligned with the axis;a first transmission which converts a first motion of the input member to a second motion and transmits the second motion to the intermediate member, the first motion being one of a rectilinear motion along the axis and a rotary motion about the axis, and the second motion being the other of the rectilinear motion along the axis and the rotary motion about the axis;a second transmission which converts the second motion of the intermediate member to the first motion and transmits the first motion to the output member; andat least one of the first transmission and the second transmission continuously and nonlinearly varies a ratio of an amount of motion of a motion transmission destination member to an amount of motion of a motion transmission source member according to the amount of motion of the motion transmission source member, whereina ratio of an amount of motion of the output member to an amount of motion of the intermediate member is larger than a ratio of an amount of motion of the intermediate member to an amount of motion of the input member. 2. A motion conversion transmission apparatus according to claim 1, wherein the first transmission converts a rectilinear motion of the input member along the axis to a rotary motion about the axis, and transmits the rotary motion to the intermediate member; and the second transmission converts the rotary motion of the intermediate member about the axis to a rectilinear motion along the axis, and transmits the rectilinear motion to the output member. 3. A motion conversion transmission apparatus according to claim 2, wherein the first transmission and the second transmission are configured to rectilinearly move the output member along the axis in the same direction as that of rectilinear motion of the input member. 4. A motion conversion transmission apparatus according to claim 3, wherein, when the amount of motion of the input member is zero, the input member and the output member are in contact with each other. 5. A motion conversion transmission apparatus according to claim 2, wherein the input member and the output member have respective portions which are engaged with each other along the axis; and the first transmission and the second transmission are provided at the portion of the input member and the portion of the output member, respectively, and are separated from each other in a circumferential direction about the axis. 6. A motion conversion transmission apparatus according to claim 5, wherein the input member and the output member have respective pairs of arm portions extending along the axis toward the output member and the input member, respectively, and the paired arm portions of the input member and the paired arm portions of the output member are disposed alternately as viewed along a circumferential direction about the axis and prevent a relative rotary motion about the axis between the input member and the output member while allowing a relative rectilinear motion along the axis between the input member and the output member. 7. A motion conversion transmission apparatus according to claim 6, wherein the input member and the output member have the same shape and are disposed along the axis in an oppositely oriented relation. 8. A motion conversion transmission apparatus according to claim 2, wherein the first transmission and the second transmission are configured to rectilinearly move the output member along the axis in a direction opposite that of rectilinear motion of the input member. 9. A motion conversion transmission apparatus according to claim 2, wherein, in cooperation with other members, the output member defines on its opposite sides two cylinder chambers which are filled with liquid and whose volumes are variable; the output member has an orifice for establishing communication between the two cylinder chambers; and, in association with rectilinear motion of the output member, the liquid flows from one of the two cylinder chambers to the other cylinder chamber through the orifice. 10. A motion conversion transmission apparatus according to claim 1, wherein the first transmission converts a rotary motion of the input member about the axis to a rectilinear motion along the axis, and transmits the rectilinear motion to the intermediate member; and the second transmission converts the rectilinear motion of the intermediate member along the axis to a rotary motion about the axis, and transmits the rotary motion to the output member. 11. A motion conversion transmission apparatus according to claim 1, wherein the first transmission continuously and nonlinearly varies a ratio of an amount of motion of the intermediate member to an amount of motion of the input member according to the amount of motion of the input member; and the second transmission continuously and nonlinearly varies a ratio of an amount of motion of the output member to the amount of motion of the intermediate member according to the amount of motion of the intermediate member. 12. A motion conversion transmission apparatus according to claim 1, wherein each of the first and second transmission includes a cam provided on the motion transmission source member and a cam follower provided on the motion transmission destination member and engaged with the cam, and, by the cam follower moving to follow the cam, the ratio of the amount of motion of the motion transmission destination member to the amount of motion of the motion transmission source member is varied continuously and nonlinearly according to the amount of motion of the motion transmission source member. 13. A motion conversion transmission apparatus according to claim 12, wherein one of the cam and the cam follower is a cam groove, whereas the other of the cam and the cam follower is a cam groove engagement member which is engaged with the cam groove and moves along the cam groove, and the cam groove of at least one of the first and second transmission extends while being inclined with respect to a circumferential direction about the axis and is curved such that an angle of inclination with respect to the circumferential direction varies gradually and continuously. 14. A motion conversion transmission apparatus according to claim 13, wherein each of the cam groove engagement members has a shaft member which is fixed to a corresponding member and extends in a radial direction, and a cam roller which is rotatably supported by the shaft member and is rollably engaged with a wall surface of the corresponding cam groove. 15. A motion conversion transmission apparatus according to claim 13, wherein the cam groove of the first transmission and the cam groove of the second transmission m ns have the same angle of inclination with respect to the circumferential direction as measured at respective positions where, when the amount of motion of the input member is zero, the cam groove engagement members are engaged with the corresponding cam grooves. 16. A motion conversion transmission apparatus comprising: an input member, an intermediate member, and an output member which are fitted to one another while being aligned with an axis and move in relation to one another while being aligned with the axis;a first transmission which converts a first motion of the input member to a second motion and transmits the second motion to the intermediate member, the first motion being one of a rectilinear motion along the axis and a rotary motion about the axis, and the second motion being the other of the rectilinear motion along the axis and the rotary motion about the axis;a second transmission which converts the second motion of the intermediate member to the first motion and transmits the first motion to the output member; andat least one of the first transmission and the second transmission continuously and nonlinearly varies a ratio of an amount of motion of a motion transmission destination member to an amount of motion of a motion transmission source member according to the amount of motion of the motion transmission source member, whereineach of the first and second transmission includes a cam provided on the motion transmission source member and a cam follower provided on the motion transmission destination member and engaged with the cam, and, by the cam follower moving to follow the cam, the ratio of the amount of motion of the motion transmission destination member to the amount of motion of the motion transmission source member is varied continuously and nonlinearly according to the amount of motion of the motion transmission source member,one of the cam and the cam follower is a cam groove, whereas the other of the cam and the cam follower is a cam groove engagement member which is engaged with the cam groove and moves along the cam groove, and the cam groove of at least one of the first and second transmission extends while being inclined with respect to a circumferential direction about the axis and is curved such that an angle of inclination with respect to the circumferential direction varies gradually and continuously, andthe motion conversion transmission apparatus includes a housing for accommodating the input member, the intermediate member, and the output member therein; the intermediate member is fitted to the input member and the output member in such a manner as to surround the input member and the output member about the axis, and supports the input member and the output member in such a manner that the input member and the output member are rectilinearly movable along the axis; the housing is fitted to the intermediate member in such a manner as to surround the intermediate member about the axis, and supports the intermediate member in such a manner that the intermediate member is rotatable about the axis; the cam groove of the first transmission and the cam groove of the second transmission are provided on the intermediate member; the cam groove engagement member of the first transmission and the cam groove engagement member of the second transmission are provided on the input member and the output member, respectively; the housing has guide grooves extending along the axis; and the cam groove engagement member of the first transmission and the cam groove engagement member of the second transmission radially extend through the cam groove of the first transmission and the cam groove of the second transmission, respectively, and are engaged with the corresponding guide grooves in such a manner as to be movable along the guide grooves. 17. A motion conversion transmission apparatus according to claim 16, wherein the input member and the output member are spaced apart from each other along the axis at the same circumferential position about the axis, and the cam groove engagement member of the first transmission and the cam groove engagement member of the second transmission are engaged with a common guide groove. 18. A motion conversion transmission apparatus according to claim 17, wherein one of the input member and the output member has a shaft portion extending along the axis toward the other of the input member and the output member, the other member has a recess which extends along the axis and receives the shaft portion in such a manner that the shaft portion is rectilinearly movable along the axis in relation to the recess, the cam groove engagement member of the first transmission and the cam groove engagement member of the second transmission are provided at a portion around the shaft portion and the recess and are spaced apart from each other around the axis, and the portion around the recess has a slit which allows the cam groove engagement members provided at the shaft portion to move rectilinearly along the axis in relation to the portion around the recess. 19. A motion conversion transmission apparatus according to claim 17, wherein a range in which the cam groove of the first transmission extends along the axis and a range in which the cam groove of the second transmission extends along the axis overlap each other at least partially as viewed along a circumferential direction about the axis. 20. A motion conversion transmission apparatus according to claim 17, wherein the motion conversion transmission apparatus includes a housing for accommodating the input member, the intermediate member, and the output member therein; the input member and the output member are fitted to the intermediate member in such a manner as to surround the intermediate member about the axis, and supports the intermediate member in such a manner that the intermediate member is rectilinearly movable along the axis; the housing is fitted to the input member and the output member in such a manner as to surround the input member and the output member about the axis, and supports the input member and the output member in such a manner that the input member and the output member are rotatable about the axis; the cam groove of the first transmission and the cam groove of the second transmission are provided on the input member and the output member, respectively; the cam engagement member of the first transmission and the cam engagement member of the second transmission are provided on the intermediate member; the housing has guide grooves extending along the axis; and the cam groove engagement member of the first transmission and the cam groove engagement member of the second transmission radially extend through the cam groove of the first transmission and the cam groove of the second transmission, respectively, and are engaged with the corresponding guide grooves in such a manner as to be movable along the guide grooves. 21. A motion conversion transmission apparatus comprising: an input member, an intermediate member, and an output member which are fitted to one another while being aligned with an axis and move in relation to one another while being aligned with the axis;a first transmission which converts a first motion of the input member to a second motion and transmits the second motion to the intermediate member, the first motion being one of a rectilinear motion along the axis and a rotary motion about the axis, and the second motion being the other of the rectilinear motion along the axis and the rotary motion about the axis;a second transmission which converts the second motion of the intermediate member to the first motion and transmits the first motion to the output member; andat least one of the first transmission and the second transmission continuously and nonlinearly varies a ratio of an amount of motion of a motion transmission destination member to an amount of motion of a motion transmission source member according to the amount of motion of the motion transmission source member, whereineach of the first and second transmission includes a cam provided on the motion transmission source member and a cam follower provided on the motion transmission destination member and engaged with the cam, and, by the cam follower moving to follow the cam, the ratio of the amount of motion of the motion transmission destination member to the amount of motion of the motion transmission source member is varied continuously and nonlinearly according to the amount of motion of the motion transmission source member,one of the cam and the cam follower is a cam groove, whereas the other of the cam and the cam follower is a cam groove engagement member which is engaged with the cam groove and moves along the cam groove, and the cam groove of at least one of the first and second transmission extends while being inclined with respect to a circumferential direction about the axis and is curved such that an angle of inclination with respect to the circumferential direction varies gradually and continuously,each of the cam groove engagement members has a shaft member which is fixed to a corresponding member and extends in a radial direction, and a cam roller which is rotatably supported by the shaft member and is rollably engaged with a wall surface of the corresponding cam groove, andeach of the cam groove engagement members has a guide roller which is rotatably supported by the shaft member and is rollably engaged with a wall surface of the corresponding guide groove extending along the direction of rectilinear motion of the input member.