A swivel assembly for an actuator includes: a rod defining a socket, the rod defining an arcuate surface at the floor of the socket; a cap dimensioned to fit into the socket, the cap defining a convex arcuate surface dimensioned to correspond to the arcuate surface of the floor of the socket; a first extended surface defined by the rod, the first extended surface, defined at least in part, by side portions of the socket providing depth to the socket; a second extended surface defined by the cap providing an extended length to the cap to allow the cap to extend out of the socket when the convex arcuate surface of the cap contacts the arcuate surface of the floor of the socket; and a cylinder assembly operatively connected to a piston and the cap to permit the piston and cap to move axially along a longitudinal axis of the cylinder assembly to move inwardly and outwardly of the cylinder assembly.

A nacelle for a wind turbine includes: a nacelle housing; a rotor shaft; a rotor hub, arranged on the rotor shaft; a first rotor shaft bearing for bearing the rotor shaft on the nacelle housing; and a second rotor shaft bearing. The first rotor shaft bearing and the second rotor shaft bearing are arranged at an axial distance to one another and the first rotor shaft bearing is arranged closer to the rotor hub than the second rotor shaft bearing. The first rotor shaft bearing has a first sliding surface having an averaged first sliding surface diameter and the second rotor shaft bearing has a second sliding surface having an averaged second sliding surface diameter. The first sliding surface faces away from the rotor hub at least in some sections, wherein the first sliding surface and the second sliding surface face one another at least in a partial section.

An electric pump includes: a casing; a shaft member whose one end portion is fixed to the casing; first and second bearing portions disposed to an outer circumferential side of the shaft member at positions close to the one end portion of the shaft member and the other end portion of the shaft member, respectively; a rotor accommodated in the casing and integrally rotating with the first and second bearing portions; an impeller fixed to the rotor at a position close to the other end portion; an impeller housing connected to the casing in a state where the other end portion is inserted into the impeller housing and accommodating the impeller; and a slide-contacting member disposed between the impeller housing and the second bearing portion and coming into slide-contact with the second bearing portion.

An air compressor or water pump including a frame in which there are mounted a stator, a rotor interacting with the stator to form a synchronous motor, and including a shaft, at least one turbine carried by the shaft, a fluid-supply channel to the turbine, and an outlet channel for compressed fluid, the shaft of the rotor being mounted rotatably on the frame about an, axis by a first and a second bearing. The first, respectively the second, bearing includes a first, respectively a second, spherical element provided on a first, respectively a second, end of the shaft and disposed centered relative to the axis of the shaft, and a first, respectively a second, housing provided in the frame having a form of a cap disposed centered relative to the axis of the shaft and provided to support the first, respectively the second, spherical element.

An assembly for use in a wellbore can include a drill string having an outer housing and a thrust bearing sleeve positioned within the outer housing of the drill string. The assembly can also include a stationary thrust bearing positioned within the thrust bearing sleeve and coaxially around a mandrel extending through a longitudinal length of the thrust bearing sleeve. The assembly can further include an interlocking component including a first end coupled to the stationary thrust bearing and a second end positioned in a recessed portion of a housing of the drill string for preventing the stationary thrust bearing from rotating about a central axis of the mandrel, and for allowing the stationary thrust bearing to rotate about one or more axes perpendicular to the central axis. The assembly can include a flexible member for opposing a rotational force applied to the stationary thrust bearing by another thrust bearing.

A downhole motor drive shaft assembly includes a drive shaft having a longitudinal rotational axis, a plurality of drive key sockets, an end housing having a longitudinal rotational axis, a plurality of circumferentially spaced axial keyways, and a concave spherical thrust bearing surface, and a drive key operatively connecting each drive key socket with a respective axial keyway for transferring torque from the drive shaft to the end housing. The drive key includes a substantially planar drive face slidably engaging the axial keyway, and a radiused, cylindrical back portion rotatably engaging the drive key socket, the substantially planar drive face and radiused, cylindrical back portion forming a nominal half-circle.

A bidirectional bearing, a drive train, a planetary gear and a wind generator having a bidirectional bearing are provided. A bidirectional bearing comprises an outer bearing shell having a first intermediate bearing shell, which is coupled to the shaft and which cooperates with the outer bearing shell. The bidirectional bearing further comprises a second intermediate bearing shell, which is arranged opposite to the outer bearing shell with respect to the first intermediate bearing shell. The second intermediate bearing shell is configured to take up a first load having a first direction from the first intermediate bearing shell. Furthermore, the first second intermediate bearing shell is configured to receive a second load having a second direction, which is substantially opposite to the first direction. The first intermediate bearing shell receives the second load from the second intermediate bearing shell and is configured to transfer this second load to the outer bearing shell.

A method and apparatus according to which the optimal radius of a thrust bearing in a well tool is determined. In one embodiment, the method includes receiving inputs representing a plurality of geometric characteristics and material properties of the well tool, the well tool including a housing, a shaft extending within the housing, and the thrust bearing, which includes convex and concave surfaces that define an interface having a radius; determining, based on the inputs, an expected value of the bending moment of the well tool in the vicinity of the thrust bearing; determining, based on the expected value of the bending moment, one or more expected values of the radial reaction force at the interface, which values depend upon the radius of the interface; and selecting, based on the one or more expected values of the radial reaction force, an optimal radius of the interface.

A method and apparatus according to which the optimal radius of a thrust bearing in a well tool is determined. In one embodiment, the method includes receiving inputs representing a plurality of geometric characteristics and material properties of the well tool, the well tool including a housing, a shaft extending within the housing, and the thrust bearing, which includes convex and concave surfaces that define an interface having a radius; determining, based on the inputs, an expected value of the bending moment of the well tool in the vicinity of the thrust bearing; determining, based on the expected value of the bending moment, one or more expected values of the radial reaction force at the interface, which values depend upon the radius of the interface; and selecting, based on the one or more expected values of the radial reaction force, an optimal radius of the interface.