A ball-screw assembly isolator is provided and includes a housing, a ball-screw, a ball-screw nut, a bearing assembly, a retaining member, a second retaining member, a first compressible member and a second compressible member. The bearing assembly is located between the housing and the ball-screw. The bearing assembly includes an inner race and an outer race. The retaining member is secured by the housing. The second retaining member is secured to the ball-screw nut. The first compressible member positioned between the housing and the outer race. The second compressible member is positioned between the outer race and the retaining member. The retaining member is configured to be preloaded to exert an axial force upon the first compressible member and the second compressible member.

A ballscrew assembly may comprise a ballscrew having an axially distributed ballscrew groove about an interior circumference of the ballscrew, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an interior circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further still, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an outer circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an interior circumference of the extended top plate and an axially distributed thrust bearing.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

A ballscrew assembly may comprise a ballscrew having an axially distributed ballscrew groove about an interior circumference of the ballscrew, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an interior circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an outer circumference of the extended top plate, and an axially distributed thrust bearing. Further still, a ballnut assembly may comprise a ballnut having an axially distributed ballnut groove about an outer circumference of the ballnut, an extended top plate having an axially distributed extended top plate groove disposed on an interior circumference of the extended top plate and an axially distributed thrust bearing.

An internal ball recirculation insert for a ball screw assembly. The ball screw assembly having a ball nut with at least one radial bore though it, a ball screw and load bearing balls. The ball screw and ball nut having complimental helical grooves, forming helical ball raceways when the ball screw and ball nut are assembled. The internal ball recirculation insert sized to fit into the radial bore of the ball nut, having a body portion, securing arms, a ball channel for channeling balls from one ball raceway to another and a friction or retention device around the circumference of the body portion. The friction device extending outwardly from a side wall of the recirculation insert, and contacting a wall of the radial bore in the ball nut.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.

Medical devices in accordance with various embodiments of the present invention employ one or more coaxial screw gear sleeve mechanisms. In various embodiments, coaxial screw gear sleeve mechanisms include a post with a threaded exterior surface and a corresponding sleeve configured to surround the post, the corresponding sleeve having a threaded interior surface configured to interface with the threaded exterior surface of the post and a geared exterior surface. A drive mechanism can be configured to interface with the geared exterior surface of the sleeve, causing the device to expand.