The disclosure relates to an actuator having a planetary roller screw drive comprising a housing having a cylinder chamber and a fluid reservoir forming one common volume and the housing is filled with a hydraulic fluid. The planetary roller screw drive comprises a spindle having a profiling, which meshes with a plurality of planetary rollers, which are arranged around the spindle and are supported at both ends in a planetary roller carrier. The planetary rollers mesh with an inner profiling of an internal ring gear surrounding the planetary rollers and the planetary rollers are supported in a sleeve surrounding the internal ring gear. According to the disclosure, the planetary roller carrier and/or the sleeve comprise one or more flow ducts connecting the interior and the exterior of a chamber defined radially by the sleeve and axially by the planetary roller carriers to one another.

A hydrostatically operated clutch system having a hydrostatic clutch actuator for hydrostatically operating a clutch, in particular a pulse separation clutch of a hybrid drive, such that the hydrostatic clutch actuator is combined with a valve arrangement which is to be opened actively and enables the clutch to be engaged rapidly.

A clutch drive unit 220 includes a crank arm 221 configured to rotate by rotary driving of a clutch actuator 231. The crank arm 221 includes an output pin 222 configured to press a master cylinder 232, and a receiving pin 223 configured to receive pressing force P from an extendable body 228. The extendable body 228 includes a lock spring 228a with such strength that the pressing force P is generated. The pressing force P allows pressing moment PM greater than reactive force moment RM based on reactive force R acting on the crank arm 221 from a clutch 210 to act on the crank arm 221. The extendable body 228 is, by the stretching force of the lock spring 228a, provided in a stretched state between the receiving pin 223 and a holder receiving pin 229.

A clutch actuator for transmitting a disengaging force to a disengaging device of a clutch includes an actuating element to which the disengaging force can be applied and includes a piston rod for transmitting the disengaging force from the actuating element to the disengaging device. The piston rod is mounted against a connection region of the actuating element such that the piston rod can be moved towards the connection region by the clutch reaction force of the clutch, and the positioning of the connection region and the piston rod relative to each other as a result of the movement can be fixed by applying the disengaging force to the actuating element. The actuating element is designed to at least partly deflect the disengaging force so as to produce a normal force and/or a radial force which acts between the connection region and the piston rod, and the normal force and/or the radial force fixes the position of the connection region and the piston rod relative to each other.

An actuating device for the selection and/or actuation of a gear ratio of a motor vehicle transmission and for engaging and/or disengaging a motor vehicle clutch, having a drive motor which drives a drive shaft that is connectible non-rotatingly to a gear selector drum of a transmission actuating device to move and/or rotate the gear selector drum, the gear selector drum also being connected to a transmission, and having a clutch actuating device which controls a release bearing of a clutch, wherein a master cylinder of the clutch actuating device, which is connected hydraulically to a slave cylinder that moves the release bearing, is actuatable depending on the position of the drive shaft, wherein an actuating segment which protrudes in the radial direction from the drive shaft is connected non-rotatingly to the drive shaft and the actuating segment actuates the master cylinder when the drive shaft is rotated in at least one direction of rotation, as well as to a drivetrain having such an actuating device is provided.

A vehicle includes a body frame, an engine, a transmission, a transmission case, and a shift actuator. The engine includes an engine case attached to the body frame, and a crankshaft supported by the engine case. The transmission case is spaced apart from the engine case, and houses the transmission. The shift actuator is connected to a shift drum of the transmission. At least a portion of the transmission case overlaps with the engine case as viewed along the axis of the crankshaft. The shift actuator is fixed to the transmission case.

An actuator system for hydraulic actuation of a clutch comprises a master cylinder with a master piston, a readjustment container for containing hydraulic fluid, a connection opening between the readjustment container and the master cylinder, where a degree of openness of the connection opening is dependent on the position of the master piston, and a hydraulic actuator to control a position of the master piston. In an actuator system, a control device for controlling the hydrostatic actuator is also provided, such that a speed of motion of the master piston is high while the connection opening is wide open, and low while the connection opening is open a little. In a method according to the disclosure, a position of the master piston is detected, and the actuator is controlled at different speeds depending on the position or the degree of openness.

An actuator assembly can include a housing, first and second pistons, and spring. The housing can include first and second cylinders disposed about an axis. The first piston and cylinder can define a first chamber in fluid communication with an inlet. The second piston and cylinder can define a second chamber in fluid communication with an outlet. Opposite ends of the spring can be coupled for axial translation with the first and second piston, respectively. The spring can translate the first piston to provide high volume, low pressure fluid to the outlet when a pressure in the first chamber is less than a predetermined pressure. When the pressure in the first chamber is equal to, or greater than, the predetermined pressure and the second piston is translated in the first axial direction, the spring can compress and the second piston can provide low volume, high pressure fluid to the outlet.