Abstract: Multi-recess hydrostatic journal bearings support a rotating shaft and have inclined surfaces, each inclined surface forming a variable radial gap with the surface of the shaft, the variable gaps converging in the direction of rotation of the shaft to increase hydrodynamic forces, reduce a turbulent component of shear friction, and improve the thermal stability of the journal bearing. The inclined surfaces can be formed in one or more of portions of recess bottoms in recesses, portions of gap lands surrounding recesses, and portions of an inner surface of a bushing.

Abstract: A spindle includes a housing, a shaft rotatably mounted to the housing, a first bearing arrangement and a second bearing arrangement. The first bearing arrangement has at least one first pocket defined between the first bearing arrangement and the shaft forming a first radial hydrostatic bearing and a longitudinal recess between the first bearing arrangement and the shaft forming a first portion of a thrust hydrostatic bearing. Fluid supplied to the first portion of the thrust hydrostatic bearing is supplied thereto from the at least one first pocket directly through a first radial gap defined between the first bearing arrangement and the shaft. The second bearing arrangement has a longitudinal chamber between the second bearing arrangement and the shaft forming a second portion of the thrust hydrostatic bearing. Longitudinal forces on the shaft from the first portion of the thrust longitudinal bearing and the second portion of the thrust longitudinal bearing are in opposing directions.

Abstract: A machine for rotating a part includes a rotatable shaft having at least one first surface configured to form a first hydrostatic bearing between the first surface and a substantially cylindrical surface of a part rotationally mountable thereat such that the part rotates coaxially about the substantially cylindrical surface. The machine further includes a stationary fixture having at least one stationary surface having substantially a non-cylindrical shape that is positioned and configured to form a second hydrostatic bearing between the at least one stationary surface and a complementary surface on the part.

Abstract: A hydrostatic arrangement for a spin welding machine includes, a spindle rotationally supported with at least one of a thrust hydrostatic bearing and a journal hydrostatic bearing, and a hydraulic unit configured to supply liquid to the at least one of a thrust hydrostatic bearing and a journal hydrostatic bearing at at least two different pressures.

Abstract: A spindle includes a shaft, at least one non-contact bearing in operable communication with the shaft, and a housing in operable communication with the at least one non-contact bearing. The shaft is rotatable relative to the housing, and at least one non-contact thrust bearing in operable communication with the shaft is configured to transfer oscillations to the shaft in directions parallel to an axis of the shaft.

Abstract: Multi-recess hydrostatic journal bearings support a rotating shaft and have inclined surfaces, each inclined surface forming a variable radial gap with the surface of the shaft, the variable gaps converging in the direction of rotation of the shaft to increase hydrodynamic forces, reduce a turbulent component of shear friction, and improve the thermal stability of the journal bearing. The inclined surfaces can be formed in one or more of portions of recess bottoms in recesses, portions of gap lands surrounding recesses, and portions of an inner surface of a bushing.

Abstract: A method and device for simultaneous compensation of five existing components of deviation from the ideal linear motion of solid unit moving hydro (air) static slides and using five independent flow control valves whose valves connections to the recesses and commutations between recesses are made in such a way that every valve is responsible for compensation only for one component of deviation.

Abstract: The present invention relates to an improved spindle unit. The spindle unit includes a body, an external shaft placed into the body and rotating on bearings relative to the body, and an internal shaft placed into the external shaft and coupled thereto. The spindle unit further includes front and rear static journal bearings and a thrust bearing between the external and internal shafts. Flow control valves are provided which have their outlets connected to recesses communicating with the rear and front journal bearings. Operation of the valves in response to measured parameters controls the position of the internal shaft relative to the rotation axis of the external shaft. This is accomplished by controlling the flow of fluid to recesses associated with the front and rear journal bearings. By controlling the position of the internal shaft, one can insure that a workpiece attached to the internal shaft is automatically centered.

Abstract: The present invention relates to a spindle unit which is able two work both in a low speed powerful roughing regime and medium and high speed precision semi-finishing and finishing. The spindle unit includes a body, a shaft placed into the body, journal bearings between the body and the shaft, and at least one journal-thrust ball bearing assembly placed between the body and the shaft. A hydraulic or pneumatic cylinder is used to move the shaft in an axial direction. The spindle unit further has a pad placed on at least one side of the hydraulic or pneumatic cylinder. As a result of this construction, the spindle unit can work as a fully restricted spindle unit with and without additional ball bearing support.