A dustproof device is provided for use with a ball screw which includes a screw rod and a nut mounted around the screw rod. The dustproof device includes an annular body and an elastic valve plate. The annular body is provided at one end of the nut and penetrated by the screw rod and has an outer annular surface provided with a debris exit. The debris exit has one end in communication with a spiral passage formed between the screw rod and the nut. The elastic valve plate, which is provided at the opposite end of the debris exit of the annular body, can be pushed open by a fluid and thus opens the debris exit, allowing the debris generated by the ball screw to be discharged through the debris exit along with the fluid, thereby contributing to extending the service life of the ball screw.

A rotary seal comprising: a shaft with a chromium oxide coating provided at a seal contact area; wherein said coating has a hardness of at least 55 Rockwell-C. The coating may have a surface roughness parameter (Ra) of between 0.2 and 0.4 circular. The coating may have a thickness of at least 0.1 mm. The coating layer forms part of a rotary seal with a flexible seal element that is biased into contact with the surface of the coating. The flexible seal element may be biased against the shaft by a spring to increase the pressure of the flexible seal element against the coating. The coating is preferably deposited by a plasma spray process.

A ballscrew assembly includes a nut having a first helical groove formed on a radially inner surface and defining an axis, a screw disposed along the axis (X) and within the nut and that includes a second helical groove formed on a radially outer surface and opposed to the first helical groove so as to form a helical raceway. The assembly also includes a plurality of balls disposed in the helical raceway and an annular seal disposed radially between the nut and the screw. The seal includes a resilient body and a layer formed of PTFE and disposed radially between the resilient body and the screw and configured to contact the radially outer surface of the screw. An optional annular scraper is disposed axially adjacent to the seal and is configured to receive fluid at one axial end and expel fluid at a second axial end.

A helical gearing for driving an adjusting element, which may be an actuator or a piston of a piston-cylinder unit, is driven by an electric motor. The adjusting element may be moved along an axis. The drive apparatus has a rotor, or a translator rotatably mounted in a housing by a bearing and fixedly connected to the input of or formed integrally with the helical gearing. The output of the helical gearing is connected to or formed integrally with the adjusting element. An anti-twist means may prevent the adjusting element from twisting in the circumferential direction about the axis. The helical gearing and/or at least part of the adjusting element is/are formed to be transversely elastic to the axis of rotation, at least in one region.

An electric actuator includes: a drive part (2); a motion conversion mechanism part (3) configured to convert a rotary motion from the drive part (2) to a linear motion in an axial direction parallel with an output shaft (10a) of the drive part (2); a driving force transmission part (4) including a transmission gear mechanism (28) configured to transmit a driving force from the drive part (2) to the motion conversion mechanism part (3); and a motion-conversion-mechanism support part (5) including a double-row bearing (40) configured to support the motion conversion mechanism part (3), wherein the double-row bearing (40) is arranged on one side in the axial direction with respect to the transmission gear mechanism (28).

A waterproof structure including an extension shaft disposed at an upper side of a vertically extending ball screw spline shaft so as to be coaxial with the ball screw spline shaft, a cylindrical cover member that covers the extension shaft and the ball screw spline shaft and is configured to be extended and shortened in a direction along a longitudinal axis of the extension shaft, and a rotary connection unit that connects the ball screw spline shaft and the extension shaft to each other so that the ball screw spline shaft and the extension shaft are configured to rotate relative to each other around the longitudinal axis, where an upper end of the cover member is fixed to an upper end of the extension shaft.

A linear motion device and a linear motion device component are provided. The linear motion device includes a screw, a nut, an end cover, and a scrape plate. The nut is fitted over the screw, and a spiral outer groove of the screw and a spiral inner groove of the nut correspond to each other to form a ball groove. The end cover is fixed to the nut. A first through hole portion is defined through the end cover and corresponds to the nut. An engaging groove is arranged on a first surface of the end cover. The scrape plate is assembled with the end cover. A second through hole portion is defined through the scrape plate and corresponds to the nut. An engaging member is arranged on the scrape plate and assembled with the engaging groove.

A linear actuator (1) comprising an electric motor (20), a transmission (40), a spindle (80) being connected to the transmission (40), a spindle nut (81) being arranged on the spindle (80), a housing (10), an outer tube (3) being connected to the housing (10), and an inner tube (2) being connected to the spindle nut (81). The spindle nut (81) and the inner tube (2) are guided inside the outer tube (3). The transmission (40) including a transmission housing (41), a transmission input end and a transmission output end positioned opposite the transmission input end. A coupling (30) including a first coupling part (32) being connected to the output end of the transmission, a second coupling part (34) being connected to the end of the spindle and a coupling member (36) disposed between the first and second coupling parts (32, 34) and slidably engaged with the first and second coupling parts (32, 34).

Embodiments of an actuator assembly for a power tailgate system are disclosed. The actuator assembly includes an actuator having a housing, a guide with a first end extending from the housing and a second end opposite the first end, and a slide coupled to the guide so as to be movable with respect to the guide second end. The actuator assembly also includes a bellows having a first end attached to the guide first end, a second end opposite the first end and attached to an end of the slide, and a body extending between the first and second ends. At least one hole is formed in the bellows proximate the bellows second end and enables fluid communication between an interior of the bellows and an exterior of the bellows. The bellows may expel moisture collected therein during operation of the actuator.

Linear actuator comprising a housing (1) consisting of two parts (1a, 1.sub.b), an electric motor (3) with a motor shaft, a transmission (8-11) in connection with the motor shaft, a spindle unit in connection with the transmission, where the spindle unit comprises at least a spindle (7) with a spindle nut (14) and where the spindle (7) is equipped with a bearing (12), an adjustment element (13) in connection with the spindle unit. The linear actuator is characterized in that a mounting unit (2) is embedded in the housing, said mounting unit (2) has a front and a rear end, and where the motor (3) is placed on the rear end of the mounting unit (2) and the spindle (7) is mounted on the front end of the mounting unit (2), and where the transmission (8-11) is located inside the mounting unit (2). In addition to being able to reduce the number of components with this construction, e.g. the activation element (13), the front mounting (15) and the spindle nut (14) can be moulded as one single plastic unit, it also allows for a slackening of the tolerances as the assembly of the components is considerably simplified, namely only with regard to the mounting unit (2). In that connection, the transmission (8-11) is expediently placed in the mounting unit (2).