A joining outer diameter portion located at an axial-direction intermediate portion and fitting tapered outer diameter portions located on both axial-direction sides across the joining outer diameter portion are formed on an outer peripheral face portion of an inner metal member. A joining inner diameter portion corresponding to the joining outer diameter portion and having a smaller diameter than the joining outer diameter portion so as to overlap with the joining outer diameter portion, and fitting tapered inner diameter portions corresponding to the fitting tapered outer diameter portions are formed on an inner peripheral face portion of an outer metal member. The joining portions are joined by means of resistance heating generated by conducting electricity while they are pressurized in the axial direction. The fitting tapered portions are brought into a fitted state in association with the joining.

A thrust washer and a differential containing a thrust washer. The differential has a housing, a spider and one or more spider gears. The thrust washer includes a body having an annular shape and a width configured to approximately match with a width of the one or more spider gears. The thrust washer is further configured to engage with the spider to prevent or reduce the thrust washer from rotating relative to the housing when the thrust washer is installed in the differential.

A thrust washer and a differential containing a thrust washer. The differential has a housing, a spider and one or more spider gears. The thrust washer includes a body having an annular shape and a width configured to approximately match with a width of the one or more spider gears. The thrust washer is further configured to engage with the spider to prevent or reduce the thrust washer from rotating relative to the housing when the thrust washer is installed in the differential.

A differential gear accommodated in a differential case, includes: an axial cylinder having a cylindrical shape fitted onto a shaft; an annular wall having an annular shape protruding from an outer circumferential surface of the axial cylinder; a gear protruding from the annular wall on one side with respect to an axial direction of the shaft; a reinforcing rib protruding from an outer circumferential surface of the annular wall; and a first recess formed by boring the annular wall and opening the other side with respect to the axial direction of the shaft.

A differential gear accommodated in a differential case, includes: an axial cylinder having a cylindrical shape fitted onto a shaft; an annular wall having an annular shape protruding from an outer circumferential surface of the axial cylinder; a gear protruding from the annular wall on one side with respect to an axial direction of the shaft; a reinforcing rib protruding from an outer circumferential surface of the annular wall; and a first recess formed by boring the annular wall and opening the other side with respect to the axial direction of the shaft.

Methods and systems for a differential assembly are provided herein. In one example, a diagnostic method includes generating a clutch fault according to a variance between an initial engagement position and a lock point position of a clutch motor that occur during engagement of an interaxle differential (IAD) locking clutch coupled to the clutch motor. In the IAD system, an actuation assembly is coupled to the clutch motor and the IAD locking clutch.

Methods and systems for a differential assembly are provided herein. In one example, a diagnostic method includes generating a clutch fault according to a variance between an initial engagement position and a lock point position of a clutch motor that occur during engagement of an interaxle differential (IAD) locking clutch coupled to the clutch motor. In the IAD system, an actuation assembly is coupled to the clutch motor and the IAD locking clutch.

A downsized differential assembly having a simple structure, which can be mounted easily on automobiles. The differential assembly comprises: a first gear as an internal gear; a second gear as an external gear; a first eccentric gear as an external gear meshed with the first gear; a second eccentric gear as an internal gear meshed with the second gear; a supporting member supporting the first eccentric gear and the second eccentric gear; a first motion translating mechanism translating revolving motion of the first eccentric gear into rotary motion of the first rotary shaft; and a second motion translating mechanism translating revolving motion of the second eccentric gear into rotary motion of the second rotary shaft. Gear ratios between the first gear and the first eccentric gear and between the second gear and the second eccentric gear are different, and the first rotary shaft and the second rotary shaft are rotated in opposite directions.

A downsized differential assembly having a simple structure, which can be mounted easily on automobiles. The differential assembly comprises: a first gear as an internal gear; a second gear as an external gear; a first eccentric gear as an external gear meshed with the first gear; a second eccentric gear as an internal gear meshed with the second gear; a supporting member supporting the first eccentric gear and the second eccentric gear; a first motion translating mechanism translating revolving motion of the first eccentric gear into rotary motion of the first rotary shaft; and a second motion translating mechanism translating revolving motion of the second eccentric gear into rotary motion of the second rotary shaft. Gear ratios between the first gear and the first eccentric gear and between the second gear and the second eccentric gear are different, and the first rotary shaft and the second rotary shaft are rotated in opposite directions.

An inner plunger of a solenoid coil assembly for a differential clutch of a vehicle contributes to weight lightening and price reduction of a solenoid assembly, provide various shapes, reduce friction against an inner housing, and improve the function of the solenoid assembly. The inner plunger includes an outer wheel combined with a coil bobbin of a solenoid assembly and an inner wheel combined with an inner housing. The inner wheel is molded of insulator synthetic resin with excellent moldability, magnetic metal as the outer wheel is inserted into the outer circumferential surface of the inner wheel made of the synthetic resin, and an undercut groove is formed on the whole inner surface of the inner wheel made of synthetic resin in order to reduce friction against an inner housing.