초록 ▼

An apparatus for converting rotary motion to linear motion includes a centrally located screw member and a concentrically positioned outer member that surrounds the screw member but is spaced therefrom in order to define an annular space between the outer member and the screw member. A plurality of

An apparatus for converting rotary motion to linear motion includes a centrally located screw member and a concentrically positioned outer member that surrounds the screw member but is spaced therefrom in order to define an annular space between the outer member and the screw member. A plurality of planet assemblies are positioned around the screw member and within the annular space. Each planet assembly is comprised of a roller that has a plurality of annular grooves extending circumferentially around its exterior surface. Each pair of adjacent grooves define a ridge therebetween whereby each roller has a plurality of spaced annular ridges extending circumferentially around its exterior surface. The ridges on the rollers engage the helical thread on the screw member as well as annular grooves on the inner surface of the outer member. The outer diameter of the planet assemblies is at least equal to the outside diameter of the screw member. Further, a planet assembly carrier can be provided for holding the planet assemblies and for maintaining the planet assemblies in a symmetrical arrangement around the screw member.

대표청구항 ▼

An apparatus for converting rotary motion to linear motion comprising: an externally threaded longitudinally extending screw member having a longitudinal axis and an outer diameter; at least one outer member concentrically positioned with respect to said screw member and surrounding a portion of the

An apparatus for converting rotary motion to linear motion comprising: an externally threaded longitudinally extending screw member having a longitudinal axis and an outer diameter; at least one outer member concentrically positioned with respect to said screw member and surrounding a portion of the longitudinal extent of said screw member with an annular space being provided between an inner surface of the at least one outer member and an outer surface of the screw member, said at least one outer member having a plurality of spaced annular grooves located on the inner surface thereof, said at least one outer member having a longitudinal axis; a plurality of planet assemblies positioned within said annular space, each of said planet assemblies having a longitudinal axis and being comprised of at least one roller, each roller having a plurality of spaced annular grooves extending circumferentially around the exterior surface thereof, each pair of adjacent grooves defining an annular ridge therebetween which extends circumferentially around the exterior surface of the roller to thereby define a plurality of spaced annular ridges on each roller, each one of the majority of said ridges engaging the thread on said screw member and also engaging one of the grooves on the inner surface of said at least one outer member, the longitudinal axes of said screw member, said at least one outer member and said plurality of planet assemblies being parallel, the outer diameter of all of said planet assemblies being substantially equal and being at least equal to the outer diameter of said screw member.