Abstract: At a position of a depth of the first predetermined value from the surface of the gear portion, a surface treatment that satisfies a range of a required hardness defined in advance of the gear portion is performed. A surface treatment is performed at a depth of a second predetermined value from a surface of a bearing portion, the surface treatment satisfying a required hardness in a range prescribed in advance for the bearing portion. Since the second predetermined value is deeper than the first predetermined value, the hardness distribution is made different between the gear portion and the bearing portion. The required hardness in the gear portion and the required hardness in the bearing portion are respectively satisfied.

Abstract: A method for manufacturing a pipe includes: press-forming a plate member into a U shape; and press-forming the plate member formed into the U shape into an O shape. The pipe includes a pipe body and a tapered part tilted radially inward and protruding from one end of the pipe body. Before the plate member is press-formed into the U shape, a boundary between a portion of the plate member corresponding to the pipe body and a portion of the plate member corresponding to the tapered part is pressed from a surface of the plate member corresponding to an inner peripheral surface of the pipe to bend the portion of the plate member corresponding to the tapered part toward the surface of the plate member corresponding to the inner peripheral surface of the pipe.

Abstract: A method for manufacturing a pipe includes: press-forming a plate member into a U shape; and press-forming the plate member formed into the U shape into an O shape. The pipe includes a pipe body and a tapered part tilted radially inward and protruding from one end of the pipe body. Before the plate member is press-formed into the U shape, a boundary between a portion of the plate member corresponding to the pipe body and a portion of the plate member corresponding to the tapered part is pressed from a surface of the plate member corresponding to an inner peripheral surface of the pipe to bend the portion of the plate member corresponding to the tapered part toward the surface of the plate member corresponding to the inner peripheral surface of the pipe.

Abstract: A method for manufacturing a crankshaft including a pin portion and a journal portion includes: a preparation process of preparing a die that is formed such that a parting plane of the pin portion and a parting plane of the journal portion are spaced apart from each other in a stamping direction; and a stamping process of forming a shaft portion including the pin portion and the journal portion by stamping a blank with the die.

Abstract: Disclosed is a caulking tool used for a ring gear press-fit in the outer periphery of a flange of a differential case constituting a differential subassembly, in order to caulk a caulking portion provided on at least either end of the flange in the axial direction, with respect to a plurality of notches formed in at least either end of the ring gear in the axial direction. The notches are formed along the inner periphery of the ring gear. Each notch has a bottom part slanted at a predetermined angle with respect to the radial direction of the ring gear, and a plurality of protrusions which correspond to the notches and are projected from the slant portion, in order to press the caulking portion in the axial direction of the ring gear.

Abstract: A fastening structure for a ring-gear and a differential case comprises a differential case which is provided with: a ring gear having a gear section formed on the outer peripheral surface thereof, and a plurality of notch portions formed on the inner peripheral surface thereof; a press-fitting surface whereon the ring gear is press-fitted; and a flange section which is forced against and caulked to the notch portions, at the end of the press-fitting surface. After the ring gear has been press-fitted to the press-fitting surface, the flange section is forced toward the notch portions, and thus the differential case is caulked and fastened to the ring gear. The notch portions have stepped surfaces , and thus rattling generated during torque transmission can be suppressed.

Abstract: An annular caulking-fastened component to be fastened to a counterpart component by caulking includes a notch formed in an inner peripheral edge portion at one end side in a center axis direction, the notch being to be fixed to the counterpart component by caulking; and at least one of an inner-peripheral stepped portion formed between an inner peripheral surface and the inner peripheral edge portion and outward from the inner peripheral surface in a radial direction and an end-face stepped portion formed between an end face at one end side in the center axis direction and the inner peripheral edge portion and from the end face toward the other end side in the center axis direction.

Abstract: Disclosed is a caulking tool used for a ring gear press-fit in the outer periphery of a flange of a differential case constituting a differential subassembly, in order to caulk a caulking portion provided on at least either end of the flange in the axial direction, with respect to a plurality of notches formed in at least either end of the ring gear in the axial direction. The notches are formed along the inner periphery of the ring gear. Each notch has a bottom part slanted at a predetermined angle with respect to the radial direction of the ring gear, and a plurality of protrusions which correspond to the notches and are projected from the slant portion, in order to press the caulking portion in the axial direction of the ring gear.

Abstract: Disclosed is a structure for fastening a ring gear to a differential case. The ring gear has a gear-side press-fit face annularly formed thereon, a projected portion located at an inner position relative to the gear-side press-fit face, and a notch portion located opposite to the gear-side press-fit face across the projected portion. The differential case has a case-side press-fit face which is annularly formed thereon and over which the gear-side press-fit face is press fitted, a caulk portion which is smaller than the case-side press-fit face in outer diameter and caulked to the notch portion, and a case-side smooth face which contacts the projected portion to position the ring gear with respect to the differential case. This arrangement serves to reduce the differential case in size.

Abstract: A fastening structure for a ring-gear and a differential case comprises a differential case which is provided with: a ring gear having a gear section formed on the outer peripheral surface thereof, and a plurality of notch portions formed on the inner peripheral surface thereof; a press-fitting surface whereon the ring gear is press-fitted; and a flange section which is forced against and caulked to the notch portions, at the end of the press-fitting surface. After the ring gear has been press-fitted to the press-fitting surface, the flange section is forced toward the notch portions, and thus the differential case is caulked and fastened to the ring gear. The notch portions have stepped surfaces, and thus rattling generated during torque transmission can be suppressed.

Abstract: An annular caulking-fastened component to be fastened to a counterpart component by caulking includes a notch formed in an inner peripheral edge portion at one end side in a center axis direction, the notch being to be fixed to the counterpart component by caulking; and at least one of an inner-peripheral stepped portion formed between an inner peripheral surface and the inner peripheral edge portion and outward from the inner peripheral surface in a radial direction and an end-face stepped portion formed between an end face at one end side in the center axis direction and the inner peripheral edge portion and from the end face toward the other end side in the center axis direction.

Abstract: An end plate is made of a magnetic material, and holds an axis-direction end surface of a rotor core in which a permanent magnet is buried. The end plate includes: a protruded portion constructed so as to be caused to pressingly contact the axis-direction end surface of the rotor core when mounted in the rotor; and a depressed portion constructed so as not to contact the axis-direction end surface. The protruded portion is formed so as to contact only one of a d-axis magnetic path region and a q-axis magnetic path region that are formed by the permanent magnet within the rotor core.

Abstract: Technology which enables a first member and a second member to be fastened together strongly is provided. A bar-shaped section is formed on the first member, a hole is formed in the second member, and the bar-shaped section of the first member is pressure fitted into the hole of the second member. Here, the diameter of the circumscribed circle which circumscribes the cross-section perpendicular to the axis of the bar-shaped section is made greater than the diameter of the inscribed circle which inscribes the cross-section perpendicular to the axle of the hole. The diameter of the inscribed circle which inscribes the cross-section perpendicular to the axis of the bar-shaped section is made smaller than the diameter of the circumscribed circle which circumscribes the cross-section perpendicular to the axle of the hole.

Abstract: Technology which enables a first member and a second member to be firmly fastened together is provided. A bar-shaped section is formed on the first member, a hole is formed in the second member, and the bar-shaped section of the first member is pressure fitted into the hole of the second member. Here, peak sections which extend intermittently in the axial direction or peak sections which extend obliquely with respect to the axial direction are formed in a repeating fashion in the circumferential direction, on the side face of the harder of the bar-shaped member and the hole.

Abstract: Technology which enables a first member and a second member to be fastened together strongly is provided. A bar-shaped section is formed on the first member, a hole is formed in the second member, and the bar-shaped section of the first member is pressure fitted into the hole of the second member. Here, the diameter of the circumscribed circle which circumscribes the cross-section perpendicular to the axis of the bar-shaped section is made greater than the diameter of the inscribed circle which inscribes the cross-section perpendicular to the axle of the hole. The diameter of the inscribed circle which inscribes the cross-section perpendicular to the axis of the bar-shaped section is made smaller than the diameter of the circumscribed circle which circumscribes the cross-section perpendicular to the axle of the hole.

Abstract: Technology which enables a first member and a second member to be firmly fastened together is provided. A bar-shaped section is formed on the first member, a hole is formed in the second member, and the bar-shaped section of the first member is pressure fitted into the hole of the second member. Here, peak sections which extend intermittently in the axial direction or peak sections which extend obliquely with respect to the axial direction are formed in a repeating fashion in the circumferential direction, on the side face of the harder of the bar-shaped member and the hole.