A ball screw assembly having a ball nut including a first end, a second end, a central bore, and a ball track defined by the inner surface, a ball screw shaft including an outer surface defining a ball track, the ball screw shaft being disposed in the central bore so that the ball tracks form a ball raceway, a first stopper disposed within the ball raceway, a plurality of main balls forming a ball train, the ball train being disposed in the ball raceway, and a main spring assembly disposed in the ball raceway between a first end of the ball train and the first stopper, wherein a spring constant of the first spring portion is greater than a spring constant of the second spring portion.

This application concerns embodiments of a low cost magnetically geared lead screw (MGLS). In some embodiments, a MGLS system comprises at least an outer cylinder, an inner rotor, and a translator sandwiched between the outer cylinder and the inner rotor. In various embodiments, the MGLS overcomes some of the disadvantages of other systems by skewing magnetic pole pairs on either or both of the outer cylinder or the inner rotor instead of skewing magnetic portions of the translator. By skewing the pole pairs, the translator placed between the outer and inner cylinder is generally not required to contain any magnetic material (such as permanent magnets or magnetic rings, rare earth elements, etc.), which may otherwise cause the translator to become costly and/or heavy, or to exhibit any other number of deficiencies.

A ball-screw actuator includes a screw nut having a metal core and an over-molded plastic outer shell. The plastic outer shell includes features which would be expensive to manufacture in a single piece metal screw nut, such as an anti-rotation feature, an axial position control feature, and a lateral position control feature. The anti-rotation feature may take the form of an axial groove or of an axial ridge.

A linear drive comprising an electric motor driving a worm, a worm gear which meshes with the worm and which is connected non-rotatably to a spindle extending along a linear drive longitudinal axis or axis of rotation and which has a rear and a front end. The worm gear has a bearing seat for a rear bearing, with which the worm gear is mounted in a surrounding transmission housing. To simplify the manufacture of such a linear drive the invention proposes that the rear bearing is in the form of a fixed bearing, the spindle comprises a weldable material, a securing disk is arranged on the rear end of the spindle and the securing disk is connected to the spindle in bonded-material relationship.

An electromechanically drivable brake pressure generator for a hydraulic braking system of a vehicle, having at least one threaded drive assemblage for converting an input-drive-side rotary motion into a translational motion, and a piston/cylinder unit, actuatable by the threaded drive assemblage, for hydraulic brake pressure generation. The assemblage encompasses: a spindle that has a spindle thread; and a spindle nut that has a spindle nut thread, the spindle nut being disposed on the spindle thread of the spindle so that as one of the two spindle elements rotates, the other, which is prevented from twisting using a twist preventer, is axially displaceable. The spindle nut has a spindle nut body and at least one anti-friction layer made of plastic, which is applied on the spindle nut body and has a more pronounced anti-friction property than the spindle nut body, that anti-friction layer being applied on the spindle nut thread.

An electromechanical brake pressure generator for a hydraulic braking system of a vehicle. The electromechanical brake pressure generator includes at least one threaded drive system for converting a drive-side rotary motion into a translatory motion for the brake pressure generation. The threaded drive system includes a rotatable spindle nut, and a spindle cooperating with a thread of the spindle nut so that the spindle is axially displaceable with a rotation of the spindle nut. The threaded drive system includes a drive wheel, which is non-rotatably situated on the spindle nut and via which the spindle nut is connected to the electric motor, the drive wheel and the spindle nut being designed as separate plastic components, including a plurality of mutually corresponding connecting structures which, in the assembled state, engage one another in a form-locked manner in such a way that a torque required for rotating the spindle nut is transmittable.

A door opening and closing device for vehicles of the present invention includes: a motor drive mechanism; a first housing that accommodates the motor drive mechanism; a spindle drive mechanism connected to the motor drive mechanism; and a second housing that is arranged coaxially with the first housing and relatively moves with respect to the first housing by the spindle drive mechanism. The spindle drive mechanism includes: a spindle connected to the motor drive mechanism; a spindle nut screwed with the spindle; a push rod fixed so as not to rotate relative to the spindle nut and provided with a protrusion on its outer periphery; and a guide tube in which a guide groove guiding the protrusion of the push rod in an axial direction is formed.

An electronic dosing drive comprising a support structure, a threaded spindle with an external thread for driving a plunger, at least one first guide element is firmly connected, and is guided parallel to the threaded spindle on a second guide element, a spindle nut having an internal thread is engaged with the external thread of the threaded spindle, an electric drive motor having a motor shaft is coupled with the spindle nut and is attached to the support structure, an electric control apparatus is connected to the electric drive motor, where the external thread of the threaded spindle has multiple threaded areas that are separated from each other by first flattenings on their circumference extending in the longitudinal direction, and the first flattenings have guide areas that abut the core diameter of the internal thread of the spindle nut.

A screw element of a ball screw mechanism includes a lead screw which, at an axial end, is joined to a rod element using a friction welding process. In order to improve the friction-welded joint, prior to the friction welding process, the lead screw has a circumferential groove on the end face facing the rod element.

The present invention relates to the field of linear actuators, and in particular, to a high-efficiency high-thrust electric linear actuator for a solar panel. Compared with a conventional electric linear actuator, in the electric linear actuator for a solar panel of the present invention, a drive nut on a screw uses a copper alloy nut. The copper alloy nut used in the present invention greatly improves the strength, toughness, and fatigue-resistance performance and has high hardness and high tensile strength. The copper alloy nut and the corresponding screw are used in combination to bear higher pressure and do not fracture easily. Therefore, a small-structure high-thrust electric linear actuator can be realized. An electric linear actuator having a smaller volume is used to support the solar panel, so that small space is occupied, and transportation and use become more convenient.