A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter, and comprising a ground taper portion in at least one end portion, the taper portion having ground streaks extending in the longitudinal direction of the ferrite core, can be formed by centerless-grinding a rotating ferrite core by a rotating grinder.

A tapered ferrite core having a solid or hollow cylindrical shape with larger length than outer diameter, and comprising a ground taper portion in at least one end portion, the taper portion having ground streaks extending in the longitudinal direction of the ferrite core, can be formed by centerless-grinding a rotating ferrite core by a rotating grinder.

Disclosed is a roller taper grinding method for a planetary roller screw mechanism. The method includes steps as follows: step 1: determining basic parameters and a bearing capacity of a planetary roller screw mechanism to be machined; step 2: establishing deformation and force balance equations of the planetary roller screw mechanism according to the basic parameters and the bearing capacity of the planetary roller screw mechanism determined in step 1; step 3: iteratively computing an optimal grinding taper angle of roller grinding according to the deformation and force balance equations established in step 2; step 4: determining process parameters of roller grinding; and step 5: grinding a roller taper of the planetary roller screw mechanism by a machine tool according to the process parameters determined in step 4.

Disclosed is a roller taper grinding method for a planetary roller screw mechanism. The method includes steps as follows: step 1: determining basic parameters and a bearing capacity of a planetary roller screw mechanism to be machined; step 2: establishing deformation and force balance equations of the planetary roller screw mechanism according to the basic parameters and the bearing capacity of the planetary roller screw mechanism determined in step 1; step 3: iteratively computing an optimal grinding taper angle of roller grinding according to the deformation and force balance equations established in step 2; step 4: determining process parameters of roller grinding; and step 5: grinding a roller taper of the planetary roller screw mechanism by a machine tool according to the process parameters determined in step 4.

A superfinishing method for a bearing roller involves installation of a pair of parallel feed drums. The feed drums have guide thread surfaces each continuing in a spiral shape on an outer periphery, and each being driven to rotate about respective center axes. The feed drums through-feed a workpiece to be formed into a bearing roller while supporting and rotating the workpiece with the guide thread surfaces opposed to each other. The superfinishing method includes using a grinder to process an outer peripheral surface of the workpiece passing between the feed drums, varying a thread bottom angle of the guide thread surface based on positions along the feed drums in an axial direction, and superfinishing straight and logarithmic portions at both ends of the straight portion of a rolling surface of the bearing roller by one through-feed of the workpiece passing between the feed drums.

Provided is a grinding machine that does not require work for replacing an upper roller (12) and a lower roller (14) and that ensures interchangeability thereof, even when the outer diameter of a workpiece (W) and the inclination state of the generating line of the workpiece (W) are different. A headstock (7) of the grinding machine comprises an upper-roller device (13) on which the upper roller (12) is rotatably supported, and a lower-roller device (15) on which the lower roller (14) is rotatably supported. The upper-roller device (13) and the lower-roller device (15) are provided with vertical position adjustment mechanisms (22), (46), respectively, for modifying the height position related to the vertical direction thereof, and a turn angle adjustment mechanism (21) for modifying the inclination angles of the upper-roller device (13) and the lower-roller device (15) with respect to the horizontal direction of the center axes thereof.

Provided is a grinding machine that does not require work for replacing an upper roller (12) and a lower roller (14) and that ensures interchangeability thereof, even when the outer diameter of a workpiece (W) and the inclination state of the generating line of the workpiece (W) are different. A headstock (7) of the grinding machine comprises an upper-roller device (13) on which the upper roller (12) is rotatably supported, and a lower-roller device (15) on which the lower roller (14) is rotatably supported. The upper-roller device (13) and the lower-roller device (15) are provided with vertical position adjustment mechanisms (22), (46), respectively, for modifying the height position related to the vertical direction thereof, and a turn angle adjustment mechanism (21) for modifying the inclination angles of the upper-roller device (13) and the lower-roller device (15) with respect to the horizontal direction of the center axes thereof.

The invention provides a method for the centerless grinding of shaft parts (9), in particular of tubes for assembled camshafts, in the case of which the shaft part (9) which is to be ground, and has axial centering portions (11) on its end sides, is ground in rotatably driven fashion, in a manner which is customary in centerless grinding, in a gap between the grinding wheel (1) and regulating wheel (2). The grinding wheel (1) and regulating wheel (2) have a width which corresponds at least to the length of the shaft part (9). The shaft part (9) is ground in its end regions (28) first of all concentrically in relation to the centering portions (11), and this produces ground formations concentrically in relation to the centering portions (11). This is followed by the grinding of the intermediate region (29), which is located between the end regions (28), and then by the entire shaft part (9) being ground to size in a dimensionally accurate and dimensionally stable manner on the basis of the ground formations at the end regions (28) of the shaft part (9), said formations being made concentrically in relation to the centring portions (11) and resting on a support (16). In order to implement the method, the invention provides an appropriately dimensioned grinding-wheel and regulating-wheel pair (1, 2) in a centreless grinding machine, in the case of which regions of increased diameter, i.e. a respective profiling, are/is provided in the side regions of said machine in order to grind the end regions (28) of the shaft part (9).

The invention provides a method for the centerless grinding of shaft parts (9), in particular of tubes for assembled camshafts, in the case of which the shaft part (9) which is to be ground, and has axial centering portions (11) on its end sides, is ground in rotatably driven fashion, in a manner which is customary in centerless grinding, in a gap between the grinding wheel (1) and regulating wheel (2). The grinding wheel (1) and regulating wheel (2) have a width which corresponds at least to the length of the shaft part (9). The shaft part (9) is ground in its end regions (28) first of all concentrically in relation to the centering portions (11), and this produces ground formations concentrically in relation to the centering portions (11). This is followed by the grinding of the intermediate region (29), which is located between the end regions (28), and then by the entire shaft part (9) being ground to size in a dimensionally accurate and dimensionally stable manner on the basis of the ground formations at the end regions (28) of the shaft part (9), said formations being made concentrically in relation to the centring portions (11) and resting on a support (16). In order to implement the method, the invention provides an appropriately dimensioned grinding-wheel and regulating-wheel pair (1, 2) in a centreless grinding machine, in the case of which regions of increased diameter, i.e. a respective profiling, are/is provided in the side regions of said machine in order to grind the end regions (28) of the shaft part (9).

A machining apparatus is of an in-feed type configured to machine an outer peripheral surface of a rotating tapered roller, and includes a rotating mechanism having a lateral pair of rollers on which the tapered roller is mounted, the rotating mechanism rotating the pair of rollers, and a grinding stone that is brought into contact with the outer peripheral surface of the tapered roller mounted on the pair of rollers. Each roller of the pair of rollers is shaped like a truncated cone. Small-diameter portions of the pair of rollers come into contact with a small-diameter portion of the tapered roller. Large-diameter portions of the pair of rollers come into contact with a large-diameter portion of the tapered roller.