A return cover provided with a ball circulation path is attached to a slider, a lubricant retainer made up from a porous elastic body and in sliding contact with a guide rail of a body is supported by the return cover, and the lubricant retainer is provided therein with a lubricant storage space filled with lubricant.

A shaft member includes: an outer peripheral surface; at least one axial side surface facing an axial direction; a chamfered portion formed at a connection portion between an axial end edge of the outer peripheral surface and an outer peripheral edge of the axial side surface; and a processing target portion formed on at least a part of the outer peripheral surface. The chamfered portion includes at least one supported surface portion disposed at an axially intermediate portion of the chamfered portion and inclined radially outward as approaching the processing target portion in the axial direction. The axial end edge of the outer peripheral surface and the outer peripheral edge of the axial side surface are located radially inward than a tangent line at an axially intermediate portion of the supported surface portion, in a cross section in the axial direction.

An object of the present invention is to provide an actuator capable of reducing a shock in acceleration at the time of a turn caused by a load in a lateral direction orthogonal to an axis of the actuator even when the load is excessive while reducing manufacturing cost and manufacturing man-hours, and a tripod structure including the actuator. An actuator according to the present invention includes: a pipe; a ball screw used as a feed screw; a conversion nut used as a feed nut and screwed with the ball screw; a piston fixed integrally to the conversion nut and driven to expand and contract from a free end which is one end of the pipe; and a rolling bearing unit being provided on a tip of the free end of the pipe and including a plurality of roller followers holding the piston movably.

A non-Cartesian coordinate positioning machine that includes an extendable leg assembly for positioning a component such as a measurement probe within a working volume of the machine. The extendable leg assembly includes a first member and a second member which move relative to one another when the extendable leg assembly changes length. The first member including an axial arrangement of magnets forming part of a linear motor for extending and retracting the extendable leg assembly, and at least one resilient member for absorbing at least some of any axial thermal expansion or contraction of the magnets in use.

A coupling e.g. for an actuator, includes a housing which is preferably in the form of a ring mounted around the end of an outer rod of the actuator and which can be mounted to a component e.g. a cowl being deployed. Within the housing of the coupling is provided an eccentric bearing mount and bearing arrangement mounted eccentrically to the housing so as to permit some eccentric movement.

Various embodiments of the present technology generally relate to precise rotary motion control systems. More specifically, some embodiments relate to systems, methods, and means for providing pressure to a non-contact rotary system. In some embodiments, the rotary system comprises a rotary shaft that can rotate three hundred and sixty degrees continuously. In order for the rotary system to be entirely non-contact with any surfaces of surrounding components or housing, pressure must be supplied to a rotary air bearing that floats the rotary unit above a surface. In some examples, the bottom air bearing is a vacuum preloaded (VPL) air bearing. As such, the VPL air bearing requires a supply of positive pressure and a supply of negative pressure to stabilize the rotary unit. The present technology provides a mechanism for providing pneumatic air to the air bearing without a physical connection to the rotary shaft or air bearing.

A main shaft device is attached to a work machine. The main shaft device is provided with a main shaft that supports a tool or a workpiece, and a main shaft motor that causes the main shaft to rotate. The main shaft device is provided with bearings that are rolling bearings which support the main shaft in an inner race, and a housing and a rear housing that secure an outer race of the bearings. The housing and the rear housing are formed of a material having a coefficient of thermal expansion greater than that of the main shaft.

An adjusting device for a machine tool comprises a base body (1), a movable body (2) movable along a moving direction (X) relative to the base body, and a drive (3) for moving the movable body relative to the base body. In order to effectively damp vibrations between the movable body and the base body (in particular so-called stray vibrations) and yet still enable rapid positioning movements of the movable body relative to the base body, the adjusting device comprises an auxiliary body (10) which can be releasably fixed to the base body and, in the released state, can be moved together with the movable body relative to the base body. The adjusting device also comprises at least one vibration damper (11) which is arranged between the auxiliary body and the movable body.

A throttle unit is equipped with a grooved block including at least one minute groove formed on a plane surface, and an opposite block having a plane surface which is opposite to the minute groove. The grooved block and the opposite block are detachably joined so as to be opposite to each other. A throttle fluid path is formed by the minute groove and the plane surface of the opposite block. At least one surface of each of the minute groove is constituted by a curved surface or an inclined surface that is inclined with respect to the plane surface of the grooved block.

Disclosed is a rotary indexing table (10) having an output flange (12) which is suitable for receiving a workpiece, mounted on a housing (14) of said rotary indexing table (10) for rotation about an axis of rotation (A) and drivingly connected to at least one drive element (24) which engages a driving groove (22) in a cylindrical cam (20) which can be driven by a motor, the cylindrical cam (20) being disposed asymmetrically to the axis of rotation (A) of the output flange (12).