A roller assembly for a rotary dresser comprise a plurality of axial segments which may be in the form of discs, each disc provided with an abrasive, radially outer surface. The discs are secured in axial alignment, each in a preconfigured rotational orientation. The disc assembly has a centrally arranged aperture for receiving a rotor shaft. The abrasive surface of the assembly can be accurately presented as an array of uniformly shaped abrasive units in a predefined pattern.

Disclosed is a wheel outer rim fillet dressing device, including a rough wheel positioning system, a precision wheel positioning system, a wheel rotating system and a cutter dressing system. After a wheel is roughly positioned, an electric cylinder drives a moving plate to descend to an appropriate position, an adjusting cylinder drives a right sliding table to move right, a left sliding table moves synchronously with right sliding table under the action of a second gear rack, thus the distance between a precision positioning post on left sliding table and a precision positioning post on right sliding table is adjusted, and precision positioning posts contact vertical surface of cap seam allowance of wheel and hold the wheel tightly. The adjusting cylinder is restarted, and outer rim fillets can be dressed when the distance between two dressing cutters is adjusted to an appropriate position and under the cooperation of rotating wheel.

Disclosed is a wheel outer rim fillet dressing device, including a rough wheel positioning system, a precision wheel positioning system, a wheel rotating system and a cutter dressing system. After a wheel is roughly positioned, an electric cylinder drives a moving plate to descend to an appropriate position, an adjusting cylinder drives a right sliding table to move right, a left sliding table moves synchronously with right sliding table under the action of a second gear rack, thus the distance between a precision positioning post on left sliding table and a precision positioning post on right sliding table is adjusted, and precision positioning posts contact vertical surface of cap seam allowance of wheel and hold the wheel tightly. The adjusting cylinder is restarted, and outer rim fillets can be dressed when the distance between two dressing cutters is adjusted to an appropriate position and under the cooperation of rotating wheel.

A method is disclosed for grinding grooves on workpieces using a profiled grinding wheel, the profile of which is crushed. A reshaping crush process includes driven crush rollers, each being controlled on the basis of a rotational speed and current consumption. Thus, relative advancement between the grinding wheel and crush roller is controlled according to the speed and current consumption. A grinding machine is also disclosed for grinding a workpiece, wherein the workpiece is held by means of a workpiece spindle head. A crush device comprising a crush roller with a dedicated rotary drive is provided on the grinding machine. The grinding wheel is applied to the crush roller in order to dress the grinding wheel profile. The crush roller has a profile-crushing portion for profile-crushing the grinding wheel with a first dressing volume and a reshaping profile-crushing portion for profile-crushing the grinding wheel with a second dressing volume.

A method is disclosed for grinding grooves on workpieces using a profiled grinding wheel, the profile of which is crushed. A reshaping crush process includes driven crush rollers, each being controlled on the basis of a rotational speed and current consumption. Thus, relative advancement between the grinding wheel and crush roller is controlled according to the speed and current consumption. A grinding machine is also disclosed for grinding a workpiece, wherein the workpiece is held by means of a workpiece spindle head. A crush device comprising a crush roller with a dedicated rotary drive is provided on the grinding machine. The grinding wheel is applied to the crush roller in order to dress the grinding wheel profile. The crush roller has a profile-crushing portion for profile-crushing the grinding wheel with a first dressing volume and a reshaping profile-crushing portion for profile-crushing the grinding wheel with a second dressing volume.

Provided is a method of chamfer machining a silicon wafer which makes it possible to increase the number of machining operations that can be performed using a chamfering wheel used for helical chamfer machining in the case of obtaining a small finished wafer taper angle. The method in which helical chamfer machining is performed so that the finished wafer taper angle of an edge portion in the one silicon wafer is within an allowable angle range of a target wafer taper angle .sub.0 includes a first truing step; a first chamfer machining step; a step of determining a groove bottom diameter .sub.A of the fine grinding grindstone portion; a second truing step using a second truer taper angle .sub.2; and a second chamfer machining step. The second truer taper angle .sub.2 is made larger than the first truer taper angle .sub.1.

Provided is a method of chamfer machining a silicon wafer which makes it possible to increase the number of machining operations that can be performed using a chamfering wheel used for helical chamfer machining in the case of obtaining a small finished wafer taper angle. The method in which helical chamfer machining is performed so that the finished wafer taper angle of an edge portion in the one silicon wafer is within an allowable angle range of a target wafer taper angle .sub.0 includes a first truing step; a first chamfer machining step; a step of determining a groove bottom diameter .sub.A of the fine grinding grindstone portion; a second truing step using a second truer taper angle .sub.2; and a second chamfer machining step. The second truer taper angle .sub.2 is made larger than the first truer taper angle .sub.1.

Method for profiling a finishing tool, in particular a grinding worm, having a first and a second finishing flank; the method providing the steps of: arranging a cutting portion of a profiling tool in contact with the first flank of the thread; causing the cutting portion to slide in contact with the first flank of the thread so as to profile it; removing the cutting portion from the thread; automatically rotating the profiling tool so as to arrange the cutting portion in contact with a second flank of the thread; and causing the cutting portion to slide in contact with the second flank of the thread so as to profile it.

Herein is disclosed a method of dressing a grinding wheel, the method comprising providing a dressing roller and a grinding wheel, wherein the dressing roller comprises a hub and a plurality of polycrystalline diamond (PCD) segments mounted peripherally about the hub, each PCD segment having a pair of side surfaces extending generally radially and an end surface extending generally circumferentially between the side surfaces, the method comprising the steps of: a. rotating the dressing roller and/or the grinding wheel, and b. engaging a periphery of the dressing roller and a periphery of the grinding wheel, wherein a speed ratio qd between the dressing roller and the grinding wheel is below 0 or above +1, and wherein a rake face is located on one of said side surfaces of each PCD segment and a corresponding flank face is located on the end surface.

Herein is disclosed a method of dressing a grinding wheel, the method comprising providing a dressing roller and a grinding wheel, wherein the dressing roller comprises a hub and a plurality of polycrystalline diamond (PCD) segments mounted peripherally about the hub, each PCD segment having a pair of side surfaces extending generally radially and an end surface extending generally circumferentially between the side surfaces, the method comprising the steps of: a. rotating the dressing roller and/or the grinding wheel, and b. engaging a periphery of the dressing roller and a periphery of the grinding wheel, wherein a speed ratio qd between the dressing roller and the grinding wheel is below 0 or above +1, and wherein a rake face is located on one of said side surfaces of each PCD segment and a corresponding flank face is located on the end surface.