Abstract: A differential unit includes: a pinion gear shaft including a shaft portion and a gear portion; a ring gear meshing with the gear portion; a differential case that rotates with the ring gear; a differential gear mechanism accommodated in the differential case; a differential carrier having an accommodating space accommodating the differential case and the ring gear; and a pair of bearings supporting the pinion gear shaft such that the pinion gear shaft is rotatable with respect to the differential carrier. The differential carrier has an inner cylindrical portion, an outer cylindrical portion, and a connecting portion that are provided as a single member. The inner cylindrical portion has the pair of bearings fitted in the inner cylindrical portion. The outer cylindrical portion is provided radially outward of the inner cylindrical portion. The connecting portion connects the inner cylindrical portion and the outer cylindrical portion.

Abstract: A cutter head assembly including: (a) a main body which has a cutting-blade receiving bore and a clamping-member receiving bore partially interfering with the cutting-blade receiving bore; (b) a cutting blade received in the cutting-blade receiving bore and having a flat surface as a part of an outer circumferential surface thereof and parallel to an axis of the cutting blade; and (c) a cylindrical clamping member received in the clamping-member receiving bore and having a fitting portion and a cam portion. The cylindrical clamping member is fitted at the fitting portion in the clamping-member receiving bore. The cam portion has a cam surface whose radial distance from an axis of the fitting portion changes in a circumferential direction of the cylindrical clamping member.

Abstract: A cutter head assembly including: (a) a main body which has a cutting-blade receiving bore and a clamping-member receiving bore partially interfering with the cutting-blade receiving bore; (b) a cutting blade received in the cutting-blade receiving bore and having a flat surface as a part of an outer circumferential surface thereof and parallel to an axis of the cutting blade; and (c) a cylindrical clamping member received in the clamping-member receiving bore and having a fitting portion and a cam portion. The cylindrical clamping member is fitted at the fitting portion in the clamping-member receiving bore. The cam portion has a cam surface whose radial distance from an axis of the fitting portion changes in a circumferential direction of the cylindrical clamping member.

Abstract: A method of lapping teeth of a pair of gears by positively rotating one of the pair of gears at a predetermined constant speed, in mesh with the other gear in the presence of a lapping powder, while applying a braking torque to the other gear. The braking torque is controlled such that the braking torque is smaller at least when an angular acceleration value of the above-indicated other gear is maximum, than when the angular acceleration value is minimum. Also disposed is an apparatus for practicing the method.

Abstract: A cutting feed starting position control device for machine tools is capable of automatically shifting a cutting feed starting position in the machine tool toward a work a distance corresponding to a variation in size of a tool such as a grinding wheel due to dressing or truing, and again returning the shifted cutting feed starting position to an original position when it is desired such as a replacement of wheels, thereby completely removing various kinds of difficulties in a numerical machine tool control due to the variation in size of tools.

Abstract: A numerically controlled reversible gear system with a main output gear using two driving gears with a same number of teeth each coupled to respective one of a pair of pulse motors with same specifications connected to a single controlling equipment, wherein the driving gears are meshed with said main gear after rotationally shifting them in opposite direction by a same number of teeth within a range of attraction of respective phase of the pulse motors and either one gear acts as a driving element depending upon the direction of rotation so as to eliminate backlash of the main gear.

Abstract: A peritrochoid curved surface generating apparatus comprises an outer cylinder rotatably supported on a frame, a first central shaft rotatably journalled in the rotating axis of the outer cylinder, an inner cylinder adjustably fixed within an eccentric opening of the outer cylinder, an inner cylinder central shaft rotatably journalled in an axis of the inner cylinder, a second central shaft rotatably journalled in an eccentric opening of the inner cylinder and supporting a work table, a gear train for transmitting the rotation of the first central shaft to the second central shaft through the inner cylinder central shaft, a cylindrical tool rotatable about its axis and a rocking device supporting the tool and rockable in synchronism with the rotation of the outer cylinder.