A shaft circulation ball screw includes: a screw, a nut, a circulation member, and two fixing rings. The screw is provided with a stop portion for the two ends of the circulation member to rest against, a distance from the stop portion to a central axis of the screw is defined as a first height H, a distance from a highest point of the rolling elements which are located in the return passage to the central axis of the screw is defined as a second height Hmax, and Hmax satisfies the following relation: Hmax0.5BDHHmax.

An embodiment is an electromechanical door latch system including a latch device configured for motion between a latched position and an unlatched position. A manually actuated mechanical apparatus is coupled to the latch device and configured to move the latch device to the unlatched position in response to force applied by a user to a component of the mechanical apparatus. An electromechanical actuator system moves the latch device to an actuator unlatched position in response to an electrical signal from an access control device. The electromechanical actuator system includes a control module, a motor, and a ball screw drive including a ball screw or threaded nut, with one coupled to the motor shaft and the other configured for connection to a latch mechanism, and at least one recirculating ball circuit including ball bearings for transferring torque from the motor to the ball screw drive.

The present disclosure provides an actuator assembly comprising a ballnut having a helical track, an actuator drive unit (ADU) housing having an ADU track, and a ballscrew. In various embodiments, the ballscrew comprises a first translation bearing track, wherein the helical track and the first translation bearing track form a first translation bearing raceway in which a plurality of first translation bearing balls having a first diameter are disposed, and a second translation bearing track, wherein the helical track and the second translation bearing track form a second translation bearing raceway in which a plurality of second translation bearing balls having a second diameter are disposed, wherein the first diameter and the second diameter are not equal.

A brake assembly includes a service brake assembly and an electromechanically actuable parking brake assembly. The electromechanically actuable parking brake assembly has a ball nut assembly comprising a ball screw and a ball nut. The ball screw and ball nut form a raceway for bearing members. The bearing members circulate within an internal path formed in the ball screw.

The present disclosure provides an actuator assembly comprising a ballnut having a helical track, an actuator drive unit (ADU) housing having an ADU track, and a ballscrew. In various embodiments, the ballscrew comprises a first translation bearing track, wherein the helical track and the first translation bearing track form a first translation bearing raceway in which a plurality of first translation bearing balls having a first diameter are disposed, and a second translation bearing track, wherein the helical track and the second translation bearing track form a second translation bearing raceway in which a plurality of second translation bearing balls having a second diameter are disposed, wherein the first diameter and the second diameter are not equal.

A one-piece recirculation part intended to be housed in a cavity of a threaded member of a ballscrew mechanism comprises a bottom, facing in a reference direction of a reference axis, a recirculation path facing in the opposite direction and designed to pass through a thread of the threaded member, and at least one deflector, projecting from the recirculation path in the opposite direction to the reference direction. The deflector forms a guide face located at a distance from the recirculation path and facing in the reference direction, opposite a lumen in the one-piece part which extends parallel to the reference axis and opens onto the bottom and the recirculation path. When projected orthogonally onto a reference plane perpendicular to the reference axis, the first lumen surrounds or coincides with the guide face of the first deflector.

A retainer comprises a snap ring part substantially discontinuous-ring shaped with opposed ends defining a break to be fitted over an outer surface of a ball nut; and an outer race part of a ball return formed on an inner surface of the snap ring part to be coupled with an inner race part of the ball return, end portions of the outer race part of the ball return to be connected to openings of the ball nut for recirculating balls. The snap ring part is extended further than the end portions of the outer race part of the ball return around the outer surface of the ball nut such that the snap ring part retains the outer race part, formed on the inner surface of the retaining ring portion, on the outer surface of the ball nut to be coupled with the inner race part of the ball return.

A cam includes a cylindrical ring having a substantially circular outer section and, externally, a helical running track. The ring has a conduit that connects two ends of the external helical running track, and the conduit comprising includes a track for recirculation between the ends of the running track.

An actuator assembly comprises a ball screw drive having a ball screw spindle rotatably mounted about a spindle axis, on which a spindle nut is received, and a thread track on an outer circumferential surface of the ball screw spindle, has a portion of a ball return on a circumferential wall of the ball screw spindle, which return connects a beginning and an end of the thread track to one another. At the beginning and at the end of the thread track, an insert is inserted in which a ball race is formed, which is part of the ball return. The inserts are arranged such that each end of a ball race adjoins a portion of the ball return and another end adjoins a beginning of a thread track or an end of the thread track. In a section perpendicular to a spindle axis, an angle of the ball race to a tangent to the thread track at an adjacent beginning or end of the thread track is greater than 90 in a central portion between the first and the second end of the ball race. To determine the angle, a side of the tangent on which a portion of the thread track directly adjacent to the beginning or the end lies is selected. To produce the ball screw spindle, a channel of the ball return is introduced into the circumferential wall, a thread is introduced into an outer circumferential surface of the ball screw spindle, and in each case one depression is introduced into the outer circumferential surface at the beginning and at the end of the thread track, and inserts are inserted into the depressions.

A ball screw drive having a threaded spindle, a spindle nut and balls which circulate in a helical ball race located therebetween. Two ball deflectors engage in the ball race and a transfer channel extends therebetween that together with part of the ball race form a closed recirculation track. The ball return guide is an internal deflector. The threaded spindle includes a radially external hollow cylinder with a central symmetrical internal cavity and a cylindrical core filling this cavity. The cylindrical core is formed of first and second core halves. The transfer channel is arranged in the common separating surface of the core halves, which are designed as oblique halves, the common separating surface thereof forming a plane which intersects the central axis of the core only at one point. The ball screw drive can be used in a brake booster system, a wheel brake or generally as an actuator.