Linear actuator

Claim 2

In a linear actuator, a pair of members having portions of same in telescoping relation, a bearing unit interposed between said members at said portions thereof and including a first bearing element riding on one of said members, a second bearing element positioned to be coupled to the other of said members, and antifriction means interposed between said bearing elements, means for rotating said portion of said other member relative to said one member portion, and wedge lock means interposed between said second bearing element and said portion of said other member for wedging said bearing unit between said members in a position eccentric to said member portions and coupling said second bearing element to said other members, said bearing unit being mounted in a fixed plane that extends parallel to the transverse axis of said member portions and that is canted at an acute angle with respect to the transverse section thereof whereby said second bearing element on rotation of said other member portion rotates about an axis that is parallel to the plane that includes the axis of rotation of said other member portion and bisects the section of said member portions that is defined by said fixed plane along the major axis thereof, said first bearing element and said one member at their contacting portions being formed to define an elongate rolling contact area, whereby rotation of said other member portion will provide linear movement of said one member portion in proportion to the position of said contact area to one side of the last mentioned plane.

Claim 3

In a linear actuator, a pair of members having portions of same in concentric telescoping relation, a bearing unit interposed between said members at said portions thereof and including a first bearing element riding on one of said members, a second bearing element positioned to be coupled to the other of said members, and antifriction means interposed between said bearing elements, means for rotating said portion of said other member relative to said one member portion, and wedge lock means interposed between said second bearing element and said portion of said other member for wedging said bearing unit between said members in a position eccentric to said member portion with a force proportional to the forces resisting linear movement of said one member and coupling said second bearing element to said other member, said bearing unit being mounted in a fixed plane that extends parallel to the transverse axis of said member portions and that is canted at an acute angle with respect to the transverse section thereof whereby said second bearing element on rotation of said other member portion rotates about an axis that is parallel to the plane that includes the longitudinal axis of said member portions and bisects the section of said member portions that is defined by said fixed plane along the major axis thereof, said first bearing element and said one member at their contacting portions being formed to define an elongate rolling contact area extending circumferentially of said first bearing element, and means for positioning said contact area to one side of the last mentioned plane whereby rotation of said other member portion will provide linear movement of said one member portion.

Claim 4

In a linear actuator, a pair of members having portions of same in concentric telescoping relation, a bearing unit interposed between said members at said portions thereof and including a first bearing element riding on one of said members, a second bearing element positioned to be coupled to the other of said members, and antifriction means interposed between said bearing elements, means for rotating said portion of said other member relative to said one member portion, and wedge lock means interposed between said second bearing element and said portion of said other member for wedging said bearing unit between said members in a position eccentric to said member portion with a force proportional to the forces resisting linear movement of said one member and coupling said second bearing element to said other member, said bearing unit being mounted in a fixed plane that extends parallel to the transverse axis of said member portions and that is canted at an acute angle with respect to the transverse section thereof whereby said second bearing element on rotation of said other member portion rotates about an axis that is parallel to the plane that includes the longitudinal axis of said member portions and bisects the section of said member portions that is defined by said fixed plane along the major axis thereof, said first bearing element and said one member at their contacting portions being formed to define an elongate rolling contact area extending circumferentially of said first bearing element, and means for positioning said contact area to one side of the last mentioned plane whereby rotation of said other member portion will provide linear movement of said one member portion.

Claim 5

The linear actuator set forth in claim 2 wherein: said positioning means includes means for automatically disposing said contact area relative to said last mentioned plane in proportion to the force multiplication required to move said one member portion linearly against forces acting against same to oppose such linear movement.

Claim 6

The linear actuator set forth in claim 2 wherein: said wedge lock means comprises: bearing ball means interposed between said second bearing element and said other member, said second bearing element and said other member defining surface means for wedging engagement of said bearing ball means between same on rotation of said other member.

Claim 7

The linear actuator set forth in claim 4 wherein: said bearing ball means is biased into said wedging engagement.

Claim 8

The linear actuator set forth in claim 2 wherein: said wedge lock means comprises: bearing ball means interposed between said second bearing element and said other member, said second bearing element and said other member defining surface means for wedging engagement of said bearing ball means between same on rotation of said other member, said bearing ball means and said surface means including means for providing said wedging engagement in either direction longitudinally of said axis of rotation.

Claim 9

The linear actuator set forth in claim 6 wherein: said bearing ball means is biased into said wedging engagement.

Claim 10

In a linear actuator, a pair of members having portions of same circular in configuration and in telescoping relation axially thereof, a rolling bearing unit interposed between said members at said portions thereof and including a first race element riding on one of said members, a second race element adapted to be coupled to the other of said member, and rolling bearing antifriction means interposed between said race elements, means for rotating said portion of said other member relative to said one member portion, and ball wedge lock means interposed between said second bearing element and said portion of said other member for wedging said bearing unit between said members in a position eccentric to said member portion with a force proportional to the forces resisting linear movement of said one member, said bearing unit being mounted in a fixed plane disposed at an acute angle transversely of said member portions and being positioned so that the axis of rotation of said second bearing element on rotation of said other member portion is parallel to a plane that includes the axis of rotation of said other member portions and intersects said fixed plane along the major axis of the section defined by said fixed plane, said first bearing race at its portion contacting said one member being formed to define a spherically contoured rolling surface whereby an elongate rolling contact area between said one member and said first race element is formed extending circumferentially of said first race element, whereby when said contact area is positioned to one side of the last mentioned plane, rotation of said other member portion will provide linear movement of said one member portion.

Claim 11

In a linear actuator, a pair of members having portions of same circular in configuration and in telescoping relation axially thereof, a rolling bearing unit interposed between said members at said portions thereof and including a first race element riding on one of said members, a second race element adapted to be coupled to the other of said member, and rolling bearing antifriction means interposed between said race elements, means for rotating said portion of said other member relative to said one member portion, and ball wedge lock means interposed between said second bearing element and said portion of said other member for wedging said bearing unit between said members in a position eccentric to said member portion with a force proportional to the forces resisting linear movement of said one member, said bearing unit being mounted in a fixed plane disposed at an acute angle transversely of said member portions and being positioned so that the axis of rotation of said second bearing element on rotation of said other member portion is parallel to a plane that includes the axis of rotation of said other member portions and intersects said fixed plane along the major axis of the section defined by said fixed plane, said first bearing race at its portion contacting said one member being formed to define a spherically contoured rolling surface whereby an elongate rolling contact area between said one member and said first race element is formed extending circumferentially of said first race element, whereby when said contact area is positioned to one side of the last mentioned plane, rotation of said other member portion will provide linear movement of said one member portion.

Claim 12

A linear actuator comprising: a tubular member, a shaft member mounted for rotation within said tubular member about the longitudinal axis of said tubular member, a rolling bearing assembly interposed between said members and mounted in a fixed plane disposed at an acute angle transversely of said members and for shifting movement circumferentially of said members, said bearing assembly comprising a bearing unit comprising an inner race element, an outer race element, and rolling bearing means interposed between said elements, said outer race element defining a spherically contouRed annular surface for riding on said tubular member, and ball wedge lock means interposed between said inner race element and said shaft member for wedging said bearing unit between said members in a position eccentric to same to dispose said surface of said outer race element in rolling engagement with said tubular member, and means for rotating said shaft member, said bearing unit being disposed relative to said members such that said inner race element thereof rotates about an axis that is parallel to the plane that includes the said axis of said tubular member and bisects the section defined by said fixed plane along the major axis thereof, said outer race element and said tubular member at their contacting portions defining an elongate rolling contact area, whereby, when said contact area is positioned to one side of the last mentioned plane, rotation of said shaft member will provide linear movement of said tubular member.

Claim 13

A linear actuator comprising: a tubular member, a shaft member mounted for rotation within said tubular member about the longitudinal axis of said tubular member, a rolling bearing assembly interposed between said members and mounted in a fixed plane disposed at an acute angle transversely of said members and for shifting movement circumferentially of said members, said bearing assembly comprising a bearing unit comprising an inner race element, an outer race element, and rolling bearing means interposed between said elements, said outer race element defining a spherically contouRed annular surface for riding on said tubular member, and ball wedge lock means interposed between said inner race element and said shaft member for wedging said bearing unit between said members in a position eccentric to same to dispose said surface of said outer race element in rolling engagement with said tubular member, and means for rotating said shaft member, said bearing unit being disposed relative to said members such that said inner race element thereof rotates about an axis that is parallel to the plane that includes the said axis of said tubular member and bisects the section defined by said fixed plane along the major axis thereof, said outer race element and said tubular member at their contacting portions defining an elongate rolling contact area, whereby, when said contact area is positioned to one side of the last mentioned plane, rotation of said shaft member will provide linear movement of said tubular member.

Claim 14

The actuator set forth in claim 9 including: means for biasing said bearing unit to dispose said rolling contact area 90* from said last mentioned plane relative to said shaft axis, whereby, on initiation of rotation of said shaft member, said bearing unit shifts circumferentially of said members to provide a high force conversion ratio for overcoming inertia, and said biasing means when said inertia has been overcome automatically shifts said bearing unit circumferentially of said members to decrease the force conversion ratio in proportion to the forces resisting linear movement of said tubular member relative to said shaft member.

Claim 15

The actuator set forth in claim 9 wherein: said ball wedge lock means comprises: bearing ball means interposed between said inner race element and said shaft member, said inner race element and said shaft member defining surface means for wedging engagement of said bearing ball means between same.

Claim 16

The actuator set forth in claim 11 wherein: said bearing ball means comprises a single bearing ball.

Claim 17

The actuator set forth in claim 11 wherein: said bearing ball means comprises a pair of bearing balls spaced axially of said shaft member, said surface means including a spherically contoured concave surface formed in said inner race, and means for biasing said balls into engagement with said surface.

Claim 18

The actuator set forth in claim 11 wherein: said bearing ball means comprises a pair of bearing balls spaced axially of said shaft member, said surface means comprising frustoconical surfaces converging inwardly of said bearing unit, said balls respectively engaging the respective surfaces of said surface means, and means for biasing said balls into engagement with the respective surfaces of said surface means.

Claim 19

The actuator set forth in claim 14 wherein: said rolling bearing means comprises a pair of rows of bearing balls, said rows being spaced apart axially of said shaft member and disposed so that the balls of the respective rows ride in planes extending transversely of said shaft member that intersect said members between said contact area and the respective balls of said bearing ball means.

Claim 20

The actuator set forth in claim 9 wherein: said bearing assembly comprises three of said bearing units keyed together against rotation relative to each other, with said contact areas of the respective bearing units being disposed to balance forces transmitted to said one member.

Claim 21

The actuator set forth in claim 16 wherein: said bearing unit biasing means comprises: a torsion spring connected between said inner race element and said shaft member and disposed about said shaft member.

Claim 22

In a rolling bearing assembly, the combination comprising: a plurality of bearing units disposed in aligned side-by-side relation, said units each comprising an inner race, an outer race, and rolling bearings interposed between the respective inner and outer racEs, with adjacent inner races of the respective units being keyed by keying means against rotational movement relative to each other, said keying means including means for permitting shifting of said units in parallel planes that are coplanar with the planes of said units.

Claim 23

In a rolling bearing assembly, the combination comprising: a plurality of bearing units disposed in aligned side-by-side relation, said units each comprising an inner race, an outer race, and rolling bearings interposed between the respective inner and outer racEs, with adjacent inner races of the respective units being keyed by keying means against rotational movement relative to each other, said keying means including means for permitting shifting of said units in parallel planes that are coplanar with the planes of said units.

Claim 24

A screwless linear actuator comprising: a shaft member, a tubular member in concentric telescoping relation to said shaft member, a rolling bearing unit interposed between said members in eccentric relation thereto, said unit having a first race defining an annular spherically contoured surface disposed in contact with one of said members, a second race positioned to be coupled to the other of said members, and rolling bearings interposed between said races, wedge lock means acting between said second race and said other member for wedging said bearing unit between said members in eccentric relation thereto, and means for rotating said other member, said bearing unit being positioned relative to said members to dispose same in a fixed plane extending at an acute angle transversely of said members.

Claim 25

A screwless linear actuator comprising: a shaft member, a tubular member in concentric telescoping relation to said shaft member, a rolling bearing unit interposed between said members in eccentric relation thereto, said unit having a first race defining an annular spherically contoured surface disposed in contact with one of said members, a second race positioned to be coupled to the other of said members, and rolling bearings interposed between said races, wedge lock means acting between said second race and said other member for wedging said bearing unit between said members in eccentric relation thereto, and means for rotating said other member, said bearing unit being positioned relative to said members to dispose same in a fixed plane extending at an acute angle transversely of said members.

Claim 26

The actuator set forth in claim 11 wherein: said bearing ball means comprises a pair of bearing balls spaced axially of said shaft member, said surface means comprising frustoconical surfaces converging inwardly of said bearing unit and being formed in said other member, said balls respectively engaging the respective surfaces of said surface means, and means for biasing said balls into engagement with the respective surfaces of said surface means.

Claim 27

A linear actuator comprising: a tubular member, a shaft member mounted for rotation within said tubular member about the longitudinal axis of said tubular member, a rolling bearing assembly interposed between said members and mounted in a fixed plane disposed at an acute angle transversely of said members and for shifting movement circumferentially of said members, said bearing assembly comprising a bearing unit comprising an inner race element, an outer race element, and rolling bearing means interposed between said elements, said outer race element defining a spherically contoured annular surface for riding on said tubular member, and ball wedge lock means interposed between said inner race element and said shaft member for wedging said bearing unit between said members in a position eccentric to same to dispose said surface of said outer race element in rolling engagement with said tubular member, means for rotating said shaft member, said bearing unit being disposed relative to said members such that said inner race element thereof rotates about an axis that is parallel to the plane that includes the said axis of said tubular member and bisects the section defined by said fixed plane along the major axis thereof, said outer race element and said tubular member at their contacting portions defining an elongate rolling contact area, whereby, when said contact area is positioned to one side of the last mentioned plane, rotation of said shaft member will provide linear movement of said tubular member, said ball wedge lock means comprising bearing ball means interposed between said inner race element and said shaft member, said inner race element and said shaft member defining surface means for wedging engagement of said bearing ball means between same, retainer means for said bearing ball means comprising: a first half sleeve element on one side of said shaft member, a second half sleeve element on the other side of said shaft member, said sleeve elements being interposed between said shaft member and said inner race element, said second half sleeve element comprising two segments spaced apart axially of said shaft member, and torsion spring means connected between each of said half sleeve element segments and said inner race and acting under compression to bias said sleeve segments away froM each other.

Claim 28

A linear actuator comprising: a tubular member, a shaft member mounted for rotation within said tubular member about the longitudinal axis of said tubular member, a rolling bearing assembly interposed between said members and mounted in a fixed plane disposed at an acute angle transversely of said members and for shifting movement circumferentially of said members, said bearing assembly comprising a bearing unit comprising an inner race element, an outer race element, and rolling bearing means interposed between said elements, said outer race element defining a spherically contoured annular surface for riding on said tubular member, and ball wedge lock means interposed between said inner race element and said shaft member for wedging said bearing unit between said members in a position eccentric to same to dispose said surface of said outer race element in rolling engagement with said tubular member, means for rotating said shaft member, said bearing unit being disposed relative to said members such that said inner race element thereof rotates about an axis that is parallel to the plane that includes the said axis of said tubular member and bisects the section defined by said fixed plane along the major axis thereof, said outer race element and said tubular member at their contacting portions defining an elongate rolling contact area, whereby, when said contact area is positioned to one side of the last mentioned plane, rotation of said shaft member will provide linear movement of said tubular member, said ball wedge lock means comprising bearing ball means interposed between said inner race element and said shaft member, said inner race element and said shaft member defining surface means for wedging engagement of said bearing ball means between same, retainer means for said bearing ball means comprising: a first half sleeve element on one side of said shaft member, a second half sleeve element on the other side of said shaft member, said sleeve elements being interposed between said shaft member and said inner race element, said second half sleeve element comprising two segments spaced apart axially of said shaft member, and torsion spring means connected between each of said half sleeve element segments and said inner race and acting under compression to bias said sleeve segments away froM each other.

Claim 29

A rolling bearing unit for a screwless linear actuator that includes a shaft member, means for rotating same, and a tubular member in substantial concentric telescoping relation to the shaft member, in which the bearing unit is to be interposed between said members in a fixed plane extending at an angle transversely of the shaft member and in eccentric relation thereto, with wedge lock means acting between the bearing unit and the shaft member for wedging the bearing unit between the members in eccentric relation thereto in the operating position of the bearing unit in the actuator, said bearing unit comprising: an outer race defining an outer spherically contoured surface concentric with said unit and adapted to contact said tubular member in said operating position of said unit, an inner race in concentric relation to said outer race and defining a bore to receive the shaft member, and rolling bearings interposed between said races in force transmitting relation therebetween, said races being in coplanar relation in the fixed plane, said inner race bore being defined by a cylindrical surface that is concentric about an axis that is other than perpendicular to the plane of the bearing unit, said inner race surface having a uniform radius about said axis lengthwise of said axis.

Claim 30

A rolling bearing unit for a screwless linear actuator that includes a shaft member, means for rotating same, and a tubular member in substantial concentric telescoping relation to the shaft member, in which the bearing unit is to be interposed between said members in a fixed plane extending at an angle transversely of the shaft member and in eccentric relation thereto, with wedge lock means acting between the bearing unit and the shaft member for wedging the bearing unit between the members in eccentric relation thereto in the operating position of the bearing unit in the actuator, said bearing unit comprising: an outer race defining an outer spherically contoured surface concentric with said unit and adapted to contact said tubular member in said operating position of said unit, an inner race in concentric relation to said outer race and defining a bore to receive the shaft member, and rolling bearings interposed between said races in force transmitting relation therebetween, said races being in coplanar relation in the fixed plane, said inner race bore being defined by a cylindrical surface that is concentric about an axis that is other than perpendicular to the plane of the bearing unit, said inner race surface having a uniform radius about said axis lengthwise of said axis.