Linear actuator

Claim 2

A linear actuator comprising: a shaft member, a tubular member in substantial concentric telescoping relation to said shaft member, one of said members being threaded, a bearing unit interposed between said members, and means for rotating one of said members, said unit comprising: means for defining a raceway about said shaft member, a plurality of free rolling roller elements rolling about said raceway on actuation of said rotating means, said elements each including an elongate shank having right ridge means in lateral load transmitting rolling meshing engagement with said threading, with said element shanks each defining oppositely extending end portions forming the longitudinal ends of the respective roller elements, with said element ends being aligned transversely of said members, said roller element ends being free of journaling relative to said members, means for maintaining said ridge means of said elements in said meshing engagement with said threading, and means keyed to the member that is other than said threaded member for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof to the exclusion of said ridge means thereof.

Claim 3

The actuator set forth in claim 1 wherein: said right ridge means of each rolling element comprises a plurality of spaced right flanges in meshing relation with said threading, with the flanges of adjacent elements being scheduled longitudinally thereof to complement the pitch of said threading.

Claim 4

The actuator set forth in claim 2 wherein said restraining means comprises: grooves formed in said elements intermediate the ends thereof and aligned transversely of said members, and a plurality of rolling bearings interposed between said rolling elements and said raceway, with said bearings engaging the respective elements at their respective grooves, said raceway defining an annular bearing groove in which said bearings ride to form said maintaining means.

Claim 5

In a linear actuator of the type including a shaft member, a tubular member in substantial concentric telescoping relation to said shaft member, a bearing unit interposed between said members, and means for rotating one of said members, the improvement wherein: one of said members is threaded lOngitudinally thereof, and wherein said unit comprises: means for defining a raceway about said shaft member, a plurality of free rolling roller elements of substantially equal lengths rolling about said raceway on actuation of said rotating means, said elements each including an elongate shank having right ridge means comprising a plurality of right flanges in rolling meshing engagement with said threading, with said elements shanks each defining oppositely extending end portions forming the longitidual ends of the respective roller elements, with said element ends being aligned transversely of said members, said roller element ends being free of journaling relative to said members, means for maintaining said ridge means of said elements in said meshing engagement with said threading, and means keyed to the member that is other than said threaded member for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof to the exclusion of said flanges.

Claim 6

In a linear actuator of the type including a shaft member, a tubular member in substantial concentric telescoping relation to said shaft member, a bearing unit interposed between said members, and means for rotating one of said members, the improvement wherein: one of said members is threaded lOngitudinally thereof, and wherein said unit comprises: means for defining a raceway about said shaft member, a plurality of free rolling roller elements of substantially equal lengths rolling about said raceway on actuation of said rotating means, said elements each including an elongate shank having right ridge means comprising a plurality of right flanges in rolling meshing engagement with said threading, with said elements shanks each defining oppositely extending end portions forming the longitidual ends of the respective roller elements, with said element ends being aligned transversely of said members, said roller element ends being free of journaling relative to said members, means for maintaining said ridge means of said elements in said meshing engagement with said threading, and means keyed to the member that is other than said threaded member for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof to the exclusion of said flanges.

Claim 7

The improvement set forth in claim 4 wherein: said means for defining a raceway about said shaft member comprises a ball element carried by said shaft member and defining a spherically contoured peripheral surface, said roller elements each defining an encircling groove portion thereabout intermediate the ends thereof, said said roller element groove portions of the respective roller elements riding on said ball element surface to provide said restraining means.

Claim 8

The improvement set forth in claim 5 wherein: said tubular member comprises said one member, the threading of said one member is 45* angle threading, said right ridge means of each of said roller elements comprising a flange adjacent either end of same in meshing engagement with said threading, said flanges of each roller element being spaced apart at least a distance equivalent to the pitch diameter of said threading.

Claim 9

The improvemet set forth in claim 4 wherein: said restraining means comprises a pair of spaced apart oppositely acting thrust resisting surfaces adjacent either end of said raceway defining means and encircling said shaft member, said roller element shanks each defining adjacent either end of said bearing surfaces riding on the respective thrust resisting surfaces of said raceway, said right ridge means of each rolling element being intermediate said ends thereof.

Claim 10

The improvement set forth in claim 7 wherein: said threading is 45* angle threading, and said flanges are formed to substantially complement said threading.

Claim 11

A bearing unit for application between concentrically arranged shaft and tubular members, one of which is threaded, for moving one of said members linearly when the other member is rotated, said unit comprising: means for defining a raceway about said shaft member, a plurality of free rolling elements rolling about said raceway on actuation of the member to be rotated, said elements each including an elongate shank having right ridge means for rolling meshing engagement with said threading, means for maintaining said ridge means of said elements in meshing engagement with said threading, and means for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof.

Claim 12

A bearing unit for application between concentrically arranged shaft and tubular members, one of which is threaded, for moving one of said members linearly when the other member is rotated, said unit comprising: means for defining a raceway about said shaft member, a plurality of free rolling elements rolling about said raceway on actuation of the member to be rotated, said elements each including an elongate shank having right ridge means for rolling meshing engagement with said threading, means for maintaining said ridge means of said elements in meshing engagement with said threading, and means for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof.

Claim 13

The bearing unit set forth in claim 9 wherein: said right ridge means of each rolling element comprises a plurality of spaced flanges in meshing relation with the threading, with the flute flanges of adjacent elements being staggered longitudinally thereof to complement the pitch of said threading.

Claim 14

The bearing unit set forth in claim 9 wherein said restraining means comprises: grooves formed in said elements intermediate the ends thereof and aligned tranversely of said members, and a plurality of rolling bearings interposed between said rolling elements and Said raceway, with said bearings engaging the respective elements at their respective grooves, said raceway defining an annular bearing groove in which said bearings ride to form said maintaining means.

Claim 15

The bearing unit set forth in claim 9 wherein said restraining means comprises: said raceway being formed to define opposed radially extending bearing surfaces extending crosswise of said members against which said elements engage at either end thereof, and a cylindrical surface on which said element ridge means ride and comprising said maintaining means.

Claim 16

The bearing unit set forth in claim 9 wherein: said means for defining a raceway about the shaft member comprises a ball element carried by said shaft member and defining a spherically contoured peripheral surface, said roller elements each defining an encircling groove portion thereabout intermediate the ends thereof, with said roller element groove portions of the respective roller elements riding on said ball element surface to provide said restraining means.

Claim 17

The bearing unit set forth in claim 13 wherein: the tubular member comprises the threaded member, said right ridge means of each of said roller elements comprising a flange adjacent either end of same in meshing engagement with said threading, said flanges of each roller element being spaced apart at least a distance equivalent to the pitch diameter of said threading.

Claim 18

A bearing unit for application between a shaft member and an internally threaded tubular member received over the shaft member for driving one of said members linearly when the other is rotated, said unit comprising: an inner race adapted to be received over the shaft and defining a raceway, a plurality of bearing balls received in said raceway about said inner race, a plurality of bearing rollers riding on said bearing balls with each roller engaging an adjacent pair of said balls and extending generally longitudinally of the axis of said race, said rollers each being circumferentially grooved intermediate the ends thereof and engaging said balls at said grooves, said rollers each being formed with radial flanges on either side of said grooves that are shaped for meshing relation with the tubular member threading, and a retainer ring received about said rollers and in said roller grooves.

Claim 19

A bearing unit for application between a shaft member and an internally threaded tubular member received over the shaft member for driving one of said members linearly when the other is rotated, said unit comprising: an inner race adapted to be received over the shaft and defining a raceway, a plurality of bearing balls received in said raceway about said inner race, a plurality of bearing rollers riding on said bearing balls with each roller engaging an adjacent pair of said balls and extending generally longitudinally of the axis of said race, said rollers each being circumferentially grooved intermediate the ends thereof and engaging said balls at said grooves, said rollers each being formed with radial flanges on either side of said grooves that are shaped for meshing relation with the tubular member threading, and a retainer ring received about said rollers and in said roller grooves.

Claim 20

The bearing unit set forth in claim 15 wherein: said roller radial flanges are at right angles to the axes of the respective rollers.

Claim 21

In a linear actuator of the type including a shaft member, a tubular member is substantial concentric telescoping relation to said shaft member, a bearing unit interposed between said members, and means for rotating one of said members, the improvement wherein: one of said members is threaded longitudinally thereof, and wherein said unit comprises: means for defining a raceway about said shaft member, a plurality of free rolling elements rolling about said raceway on actuation of said rotating means, said elements each including an elongate shank having right ridge means for rolling meshing engagement with said threading, means for maintaining said ridge means of said elements in meshing engagement with said threading, and means for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof, said raceway defining means comprising said shaft member being formed to define an annular groove thereabout having a thrust resisting surface adjacent either end of and encircling same, said roller element shanks each defining adjacent either end of same bearing surfaces riding on the resepctive thrust resisting surfaces of said raceway to provide said restraining means, said right ridge means of each rolling element comprising a plurality of spaced flanges in meshing relation with said threading intermediate said ends thereof.

Claim 22

In a linear actuator of the type including a shaft member, a tubular member is substantial concentric telescoping relation to said shaft member, a bearing unit interposed between said members, and means for rotating one of said members, the improvement wherein: one of said members is threaded longitudinally thereof, and wherein said unit comprises: means for defining a raceway about said shaft member, a plurality of free rolling elements rolling about said raceway on actuation of said rotating means, said elements each including an elongate shank having right ridge means for rolling meshing engagement with said threading, means for maintaining said ridge means of said elements in meshing engagement with said threading, and means for restraining said elements from movement longitudinally of said members against lateral loads and engaging the shanks thereof, said raceway defining means comprising said shaft member being formed to define an annular groove thereabout having a thrust resisting surface adjacent either end of and encircling same, said roller element shanks each defining adjacent either end of same bearing surfaces riding on the resepctive thrust resisting surfaces of said raceway to provide said restraining means, said right ridge means of each rolling element comprising a plurality of spaced flanges in meshing relation with said threading intermediate said ends thereof.

Claim 23

The improvement set forth in claim 17 wherein: said tubular member comprises said one member, the threading of said one member is 45* angle threading, said roller elements having sufficient length axially of said shaft member such that for each roller element diagonal lines between the portions of the bearing surfaces thereof engaging the respective thrust resisting surfaces and extending through like points on the opposite sides of the respective roller elements at opposite ends thereof intersect adjacent the axial midportion of the respective rollers at 90* angles and intersect at 45* angles with the generatrix of a right cylinder formed along the pitch diameter of said threading.

Claim 24

The improvement set forth in claim 18 wherein: said raceway defining means comprises the shaft member being formed to define an annular groove thereabout having a thrust resisting surface adjacent either end of and encircling same, said roller element shanks each defining adjacent either end of same bearing surfaces riding on the respective thrust resisting surfaces of said raceway to provide said restraining means, said right ridge means of each rolling element comprising a plurality of spaced flutes in meshing relation with said threading intermediate said ends thereof.

Claim 25

The improvement set forth in claim 19 wherein: the tubular member comprises said one member, the threading of said one member is 45* angle threading, said roller elements having sufficient length axially of the shaft member such that for each roller element diagonal lines between the portions of the bearing surfaces thereof engaging the respective thrust resisting surfaces and extending through like points on the opposite sides of the respective roller elements at opposite ends thereof intersect adjacent the axial midportion of the respective rollers at 90* angles and intersect at 45* angles with the generatrix of a right cylinder formed along the pitch diameter of said threading.