A vacuum chuck includes: a vacuum chuck stage having a circular vacuum surface; a vacuum protection pad provided to the vacuum surface; an annular or arc-shaped concave portion dividing the vacuum surface into a central region located closer to a center of the vacuum surface and an outer circumferential region located on an outer circumferential side; and radially-extending concave portions formed in the central region. The vacuum protection pad has through holes in communication with the radially-extending concave portions, and the vacuum protection pad is bonded to the vacuum surface at the central region excluding the radially-extending concave portions.

A bore finishing tool has an arbor with a tapered outer circumferential surface and a sleeve over the arbor having a tapered inner circumferential surface cooperatively disposed in surface to surface overlaying relation to at least a substantial portion of the tapered outer circumferential surface of the arbor. The sleeve is adjustably movable relative to the arbor for expanding a diametrical extent of the sleeve and has a plurality of internal material relief features at circumferentially spaced locations in the tapered inner circumferential surface extending partially through the sleeve so as to reduce a level of force required for expanding the diametrical extent of the sleeve. Exemplary material relief features include flutes and fractures. The sleeve can also include an external retraction feature enabling application of a retraction force by an external device for reducing the diametrical extent.

A bore finishing tool has an arbor with a tapered outer circumferential surface and a sleeve over the arbor having a tapered inner circumferential surface cooperatively disposed in surface to surface overlaying relation to at least a substantial portion of the tapered outer circumferential surface of the arbor. The sleeve is adjustably movable relative to the arbor for expanding a diametrical extent of the sleeve and has a plurality of internal material relief features at circumferentially spaced locations in the tapered inner circumferential surface extending partially through the sleeve so as to reduce a level of force required for expanding the diametrical extent of the sleeve. Exemplary material relief features include flutes and fractures. The sleeve can also include an external retraction feature enabling application of a retraction force by an external device for reducing the diametrical extent.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A wafer polishing apparatus includes a lower surface plate, an upper surface plate disposed over the lower surface plate, a carrier disposed between the lower surface plate and the upper surface plate and containing a wafer, and a lift unit lifting the carrier such that an upper surface of the carrier contacts a lower surface of the upper surface plate or lowering the carrier such that a lower surface of the carrier contacts an upper surface of the lower surface plate.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A double-disc straight groove cylindrical-component surface grinding disc, includes a first grinding disc and a second grinding disc, rotating relative to each other; the the first grinding disc's working face is planar; the second grinding disc's surface, opposite the first grinding disc, includes a set of radial straight grooves, with groove faces of the straight grooves are the working face of the second grinding disc; the cross-sectional outline of the working face of the second grinding disc is arcuate or V-shaped or is a V-shape having an arc; during grinding, a workpiece spins inside the straight grooves, while under the effect of an advancing apparatus, the workpiece slides in translational motion along the straight grooves. The described grinding disc device has high-volume production capabilities, and the shape accuracy and size consistency of the cylindrical roller's cylindrical surface and the efficiency in machining are improved, and machining cost is reduced.

A method for manufacturing a hypoid gear includes: a tooth cutting step of machining a shape of a tooth of the hypoid gear; a surface treatment step of forming a third intermediary gear provided with a hardened layer on a surface of the tooth; a lapping step of machining the third intermediary gear using an abrasive particle having a diameter of 14 μm or less to form a fourth intermediary gear; and a shot peening step of spraying a particle having a diameter of 160 μm or less onto the fourth intermediary gear.

A method for manufacturing a hypoid gear includes: a tooth cutting step of machining a shape of a tooth of the hypoid gear; a surface treatment step of forming a third intermediary gear provided with a hardened layer on a surface of the tooth; a lapping step of machining the third intermediary gear using an abrasive particle having a diameter of 14 μm or less to form a fourth intermediary gear; and a shot peening step of spraying a particle having a diameter of 160 μm or less onto the fourth intermediary gear.