A ball screw drive (10) including a threaded spindle (12) and a spindle nut (14) which at least partially coaxially encloses the threaded spindle (12) and has a stop at an axial end face (18). A multiplicity of balls can circulate in the space (16) between the threaded spindle (12) and the spindle nut (14). A radial stop element (22) is connected to the threaded spindle (12) in a force-fitting manner and adapted to interact with the complementary axial end face (18) of the spindle nut (14). A bearing element is provided for receiving a first longitudinal end of the spindle nut (12). The radial stop element (22) and the bearing element are designed in combination as an integral bearing/stop element (24) which has two anti-rotation features (26, 28).

A spindle nut (S) for a ball screw is conventionally designed as a hollow cylinder with a central-symmetrical middle longitudinal axis (Z). The spindle nut has an internal thread, which is designed as a ball groove (K) arranged on the cylinder inner surface. Pairs of load-relief bores (B) serve as substantially cylindrical channels for guiding the balls out of and into the ball channel (K) through the wall of the spindle nut. Each load-relief bore (B) is distinguished by a generatrix (L), which has an intersection point (C) with the thread base line of the ball channel (K) and constitutes the geometric continuation of the traveling path of a ball from the ball channel (K) into the load-relief bore (B). A tangent (T) to the cylinder surface (G) runs in a parallel manner at a spacing a >0 to the generatrix (L), both T and L being perpendicular to a common normal (R) to the middle longitudinal axis (Z).

An actuating mechanism includes a gear shifting motor, a first transmission gear, second transmission gears, gear shifting screws, a push block, a shift fork, a shift block and a linear driving device. An output shaft of the gear shifting motor is provided thereon with the first transmission gear engaged with the second transmission gears; the second transmissions gears are fixedly connected to the gear shifting screws; the gear shifting screws are in screw thread connection with the push block provided thereon with a through hole; one end of the shift block is connected to the linear driving device, and the other end is aligned with a groove on the shift fork after inserting into the through hole. The linear driving device corresponding to a shift position drives the shift block; the gear shifting motor drives the first transmission gear; and the second transmission gears drive the gear shifting screws.

A method of displacing rotors of an aircraft between a hover mode and an aircraft mode includes rotating a spindle drivingly connected to the rotors about a spindle axis to displace the rotors between the hover and aircraft modes until a component displaceable with the spindle abuts against a downstop of the aircraft and applies a load against the downstop. The method includes passively maintaining the component against the downstop to maintain the load applied against the downstop. An aircraft is also disclosed.

An external circulation ball screw includes: a screw shaft; a nut sleeved on the screw shaft and including a through hole having an opening end; and a return member mounted on the nut, and including a return groove having a return section and a continuation section, one end of the return section connected to the through hole including a connecting end which abuts against the opening end. The opening end and the connecting end are non-tangentially connected, the return section circles around a reference point, the outer wall surface of the return section is arc-shaped and centered on the reference point, a distance between the outer wall surface and the reference point is a radius of curvature, and the radius of curvature is greater than or equal to 1.2 times the ball diameter, but is less than or equal to 1.5 times the ball diameter.

An actuator and a transmission structure thereof. The transmission structure (3) includes a screw nut (31) and a ratchet guiding sleeve (32). The screw nut (31) includes one or a plurality of pawls (311). The ratchet guiding sleeve (32) is mounted on the screw nut (31), and the screw nut (31) is able to rotate relative to the ratchet guiding sleeve (32). The ratchet guiding sleeve (32) includes a ring ratchet (321) disposed on an inner circumference thereof and a plurality of track slots (322) disposed on an outer circumference thereof. One or a plurality of pawls (311) abut against the ring ratchet (321), thereby achieving the effect of smooth movements of the actuator (10) and the transmission structure (3).

A posture correction mechanism includes a carrier attached to a housing, and a gearwheel rotatably attached to the housing, the gearwheel includes a screw hole engaged with a screw which is moveable up and down relative to the housing for driving the gearwheel to rotate relative to the housing, two shafts are rotatably attached to the carrier and each has an arm rest, two gears are rotatably attached to the carrier and engaged with the gearwheel, the gears are connected to the shafts for allowing the shafts to be driven by the gearwheel to rotate relative to the carrier and for allowing the arm rests to be rotated toward or away from the user.

A posture correction mechanism includes a carrier attached to a housing, and a gearwheel rotatably attached to the housing, the gearwheel includes a screw hole engaged with a screw which is moveable up and down relative to the housing for driving the gearwheel to rotate relative to the housing, two shafts are rotatably attached to the carrier and each has an arm rest, two gears are rotatably attached to the carrier and engaged with the gearwheel, the gears are connected to the shafts for allowing the shafts to be driven by the gearwheel to rotate relative to the carrier and for allowing the arm rests to be rotated toward or away from the user.

A spring system that includes an adjustable spring system that is operated by a motor.

A spring system that includes an adjustable spring system that is operated by a motor.