Through the following steps (a) and (b), the side surface of a grinding object is ground to manufacture a ground product having a smaller diameter than that of the grinding object. In the step (a), a cup type grinding stone is disposed such that the central axis is parallel offset from a state where the central axis is orthogonal to the central axis of the grinding object. In the step (b), the cup type grinding stone is axially rotated so that the cup type grinding stone grinds the side surface of the grinding object while the grinding object is axially rotated and moved in the axial direction. Thereby, the outer peripheral surface of the grinding object is finish-ground by the bottom grinding stone portion of the cup type grinding stone while the grinding object is rough-ground by the side grinding stone portion to obtain a ground product.

A method of forming a recess in a surface of a substrate includes: providing an abrasive article comprising a structured abrasive member disposed along a peripheral surface of a support member, frictionally contacting the structured abrasive layer with a surface of a substrate, longitudinally advancing the structured abrasive layer relative to the surface of the substrate; and rotating at least one of the abrasive article or the substrate relative to the other around a rotational axis perpendicular to the surface of the substrate such that the structured abrasive layer maintains contact with and abrades the surface of the substrate. The structured abrasive member comprises a structured abrasive layer comprising shaped abrasive composites secured to a backing, wherein the backing is proximate to the support member. The shaped abrasive composites comprise abrasive particles retained in a binder material. The present disclosure also provides an abrasive wheel comprises a structured abrasive member disposed on a peripheral surface of a support wheel and display covers including a spherically concave recess abutting a cylindrical passage.

A grinding stroke control device for a valve stem grinding apparatus is fixed to a processing machine and provided for gripping a valve stem or a test bar. Using the hand wheel, the dial gauge and the positioning seat can obtain an initial position, then moving the measuring meter of the positioning mechanism along the transverse direction to make sure the valve stem has the right length with a standard valve clearance. By such arrangements, the grinding stroke control device for a stem valve grinding apparatus of the invention can have a less complicated structure and therefore is more convenient to operate.

An apparatus for machining a cylindrical workpiece has a hollow spindle with a driving center on its tip end. The hollow spindle is rotationally journaled within a spindle unit. A tail stock spindle, with a centering center on its tip end, is rotationally supported and axially movable within a centering unit. A shaft-like kelly is non-rotationally and axially movably supported within an inner bore of the spindle. A drive rotates the spindle. Cylinders axially drive the kelly and the tail stock spindle, respectively. The spindle, the tail stock spindle and the cylinders are arranged on the same axial line. The cylindrical workpiece is sandwiched between the driving center and the centering center. An outer circumferential surface of the workpiece is finish machined while rotating the workpiece under a condition where the kelly engages the workpiece within an inner bore of the workpiece.

An apparatus for machining a cylindrical workpiece has a hollow spindle with a driving center on its tip end. The hollow spindle is rotationally journaled within a spindle unit. A tail stock spindle, with a centering center on its tip end, is rotationally supported and axially movable within a centering unit. A shaft-like kelly is non-rotationally and axially movably supported within an inner bore of the spindle. A drive rotates the spindle. Cylinders axially drive the kelly and the tail stock spindle, respectively. The spindle, the tail stock spindle and the cylinders are arranged on the same axial line. The cylindrical workpiece is sandwiched between the driving center and the centering center. An outer circumferential surface of the workpiece is finish machined while rotating the workpiece under a condition where the kelly engages the workpiece within an inner bore of the workpiece.

A grinding machine for finishing turned surfaces of a rotor disc for a gas turbine engine, including a retaining mechanism for retaining the rotor disc and rotatable about a rotational axis corresponding to a central axis of the rotor disc, a spindle engaged to a grinding wheel and rotatable about a rotational axis corresponding to a central axis of the grinding wheel, the grinding wheel having an outer super abrasive surface, a translating mechanism engaged to at least one of the retaining mechanism and the spindle and actuable to provide a relative translational motion between the retaining mechanism and the spindle along three perpendicular axes, and a pivoting mechanism engaged to one of the retaining mechanism and the spindle and actuable to provide a pivoting motion of the rotational axis of one of the retaining mechanism and the spindle around a pivot axis perpendicular thereto.

A grinding machine for finishing turned surfaces of a rotor disc for a gas turbine engine, including a retaining mechanism for retaining the rotor disc and rotatable about a rotational axis corresponding to a central axis of the rotor disc, a spindle engaged to a grinding wheel and rotatable about a rotational axis corresponding to a central axis of the grinding wheel, the grinding wheel having an outer super abrasive surface, a translating mechanism engaged to at least one of the retaining mechanism and the spindle and actuable to provide a relative translational motion between the retaining mechanism and the spindle along three perpendicular axes, and a pivoting mechanism engaged to one of the retaining mechanism and the spindle and actuable to provide a pivoting motion of the rotational axis of one of the retaining mechanism and the spindle around a pivot axis perpendicular thereto.

A method and device for simultaneous centerless cylindrical grinding of multiple workpieces (11, 12, 13, 14), at least sections of which are rotationally symmetrical, the workpieces are arranged on a support apparatus (200) one behind the other between at least one grinding wheel (110) and at least one regulating wheel (120), and wherein the axis of rotation of the regulating wheel is inclined with respect to a horizontal plane extending parallel to the workpiece axes of rotation and the grinding wheel axis of rotation by an inclination angle (). During grinding the workpieces are arranged with a height offset relative to each other corresponding to at least a quarter of the inclination angle () of the axis of rotation of the regulating wheel with respect to the parallel plane to render the respective bearing angles () of the workpieces on the inclined regulating wheel consistent.

A method and device for simultaneous centerless cylindrical grinding of multiple workpieces (11, 12, 13, 14), at least sections of which are rotationally symmetrical, the workpieces are arranged on a support apparatus (200) one behind the other between at least one grinding wheel (110) and at least one regulating wheel (120), and wherein the axis of rotation of the regulating wheel is inclined with respect to a horizontal plane extending parallel to the workpiece axes of rotation and the grinding wheel axis of rotation by an inclination angle (). During grinding the workpieces are arranged with a height offset relative to each other corresponding to at least a quarter of the inclination angle () of the axis of rotation of the regulating wheel with respect to the parallel plane to render the respective bearing angles () of the workpieces on the inclined regulating wheel consistent.

Methods are disclosed for performing operations such as cleaning, inspection or data acquisition on an external surface of a hollow cylindrical tubular. Preferred embodiments include providing a fluid dispenser and an abrasion assembly on a buggy that travels up and down the length of the tubular as the tubular rotates. The fluid dispenser includes nozzles that dispense cleaning fluids onto the tubular's external surface. The abrasion assembly includes a swivel brush and a brush train providing different styles of abrasion cleaning of the tubular's external surface. Preferred embodiments include robotically monitoring abrader contact against the external surface of the tubular, and, in response, dynamically adjusting the distance between the external surface of the tubular and the abrasion assembly.