A rotary mechanical transmission, includes: a containment structure, a first rotary element, connected to a drive unit to define a mechanical power input unit and rotatable about an axis. The transmission also includes a fixed guide and a second rotary element, rotatable about said axis and defining a power output unit. A connecting element extends along the axis and couples to the first rotary element by a first threaded connection. The connecting element is also coupled with one of either the fixed guide and the second rotary element by a second threaded connection, and with the other of the fixed guide and the second rotary element by a linear guide parallel to the axis. The first threaded connection and second threaded connection have different pitches in such a way as to vary the angular speed between the connecting element and the first rotary element.

In a spindle gear mechanism (1) having a spindle component (2) with a spindle thread (21) which has a pitch which alters over a longitudinal axis of the spindle component (2), and having a threaded component (3) which engages in the spindle thread (21), wherein the two components (2; 3) can be displaced relative to one another in relation to the longitudinal axis (1) of the spindle component (2), provision is made, for the purpose of straightforward production capability and suitability for a large number of applications, for the threaded component (3) to have at least one freely movable threaded element (4) which engages in the spindle thread (21) and, during operation, adapts automatically to the pitch of the spindle thread (21).

A movement transfer mechanism for a surgical scoping device, wherein a rotational proximal input force is transformed into a longitudinal force that is conveyed down the length of an instrument channel of the scoping device, where it is transformed again into an operational movement of a distal instrument. The operational movement can be rotational movement, but may be any movement that changes the orientation or configuration of the distal instrument. By conveying a linear force along the instrument channel rather than a twisting force, the problems of slipping and discontinuous operation of the distal instrument due to friction between the instrument and the instrument channel can be reduced or eliminated.

Ball screw rotary actuator with ball cage. In one embodiment, a ball screw rotary actuator includes an outer cylinder, a piston, and inner shaft. Outer ball bearings travel in helical groove between the outer cylinder and position to rotate the piston as it translates due to fluid pressure. The inner shaft is situated radially inward of the piston, and straight grooves are disposed between the piston and the inner shaft. Inner ball bearings travel in the straight grooves and rotate the inner shaft as the piston rotates. The ball screw rotary actuator also includes an outer ball cage to position the outer ball bearings in a spaced configuration, an outer indexing gear to control a position of the outer ball cage, an inner ball cage to position the inner ball bearings in a spaced configuration, and an inner indexing gear to control a position of the inner ball cage.

Ball screw rotary actuator with independent ball paths. In one embodiment, a ball screw rotary actuator includes an outer cylinder including a fluid port, a piston configured to translate within the outer cylinder due to fluid pressure, helical grooves disposed between the outer cylinder and the piston, and outer ball bearings configured to travel in the helical grooves to rotate the piston within the outer cylinder as the piston translates. The ball screw rotary actuator also includes an inner shaft situated radially inward of the piston, straight grooves disposed between the piston and the inner shaft, and inner ball bearings configured to travel in the straight grooves, and to rotate the inner shaft as the piston rotates.

Described herein are methods and system that use electromagnetic heating to heat wellbores and the fluids therein. The heating is achieved by placing one or more permanent magnets in the wellbore and moving a metallic component and/or the one or more permanent magnets relative to each other. This generates eddy currents in the metallic component, which heat the metallic component. This heat is transferred to the fluids in the wellbore from the metallic component by convection. In some embodiments, permanent magnets are installed in the tubing to induce eddy current heating in a well by converting the linear motion of a sucker rod to rotary motion of a conducting tube using a lead or ball screw. The heater may directly integrate with existing pump jack equipment with little or no additional infrastructure required.

A rotary hydraulic actuator may be configured to output rotary motion to control a hinged surface of an aircraft. The actuator includes a nested ballscrew, ballnut, and output assembly that form concentric ball races for converting the linear motion and force of the linear actuator to rotary motion and torque of the output assembly that is connected to the hinged surface. One of the ball races is helically inclined and the other of the ball races is linear. The rotary hydraulic actuator may include a ball return structure that returns the balls from a loaded path of a ball race to an unloaded path of the ball race. The ball return structure may define a ball return path that is located at the same radial distance from the actuator centerline as the loaded path for minimizing the overall diameter of the actuator.

The present invention provides an adjustment arrangement (10), comprising a rotating input element (26) at which a first torque from a motor arrangement (18, 22) can be inputted into the adjustment arrangement, a rotating output element (16) at which a second torque can be outputted by the adjustment arrangement, and a transmission portion for converting the first torque into the second torque, the transmission portion comprising a transmission means (32) having a first threaded portion (30) and a second threaded portion (34), the first threaded portion converting a rotation of the input element (26) into an axial movement of the transmission means, and the second threaded portion converting an axial movement of the transmission means into a rotation of the output element (16).

In a rotary drive with a housing that contains a piston, a lid and a bottom, screw thread-like guiding grooves in the piston, a shaft with a rotary axis that can be rotated around an axis of the rotary drive and that encroaches in the guiding grooves, and axially parallel torque supports that are attached in the lid and/or bottom and that are embedded in guidances in the piston, with each torque support having an approximately rectangular external cross-section with a load-specific design to support torques to be transmitted and having longer rectangle sides tangentially to the shaft and shorter rectangle sides approximately in directions towards the axis.

An actuator for driving a rotatable component includes a first, rotating member comprising a screw and a second member comprising a nut threaded to said screw, wherein rotation of said first member causes axial movement of said first or second member. The component also includes a third member coupled to the second member, wherein axial movement of said first or second member causes axial movement of said third member and a fourth, rotating member coupled to said third member and connectable to said component. The system also includes a bearing system located between said third member and said fourth member, said bearing system configured to cause said fourth member to rotate upon said axial movement of said third member so as to drive said component.