A member joining structure for a differential device, the member joining structure includes a ring gear including a helical tooth extending in a rotation axis direction; a differential case that is rotated with the ring gear; and a first support that is disposed in a first position at a back surface corresponding to one end of a rotation axis of the ring gear and that connects the differential case and the ring gear, and a second support that is disposed in a second position at a back surface corresponding to another end in the rotation axis direction of the ring gear and that connects the differential case and the ring gear; wherein the first support and the second support are spaced apart from each other with a cavity therebetween.

The invention relates to an assembly for a differential unit of a vehicle, the assembly comprising: —a first housing portion (20a) designed to be assembled with a second housing portion for forming a differential carrier housing; —a first and a second supporting devices (30, 301, 302), each comprising a main portion (33) having substantially the shape of a ring and a base portion (31) attached to the first housing portion (20a) so that the main portions (33) of the first and second supporting devices (30) are substantially coaxial along a longitudinal direction (X), the first and second supporting devices being configured to support, in use, a system comprising a crown wheel (22) and a differential housing (24) containing a differential, the system having two end portions each including a bearing which has an inner ring (51) mounted on the differential housing (24), an outer ring configured to be mounted in the main portion (33) of one of the supporting devices (30), and rolling elements. The first housing portion (20a), the first supporting device (301) and the second supporting device (302) are made as a single piece. Moreover, the main portion (33) of at least one supporting device (30) comprises a notch (40) for inserting at least part of a corresponding end portion of the system (100), the notch (40) opening: —in a radial direction (Y), which is orthogonal to the longitudinal direction (X); —and in the longitudinal direction (X), towards the opposite supporting device (30).

A manufacturing method for a power transmission mechanism including: first and second shafts having first and second double helical gears; first and second rolling bearings rotatably supporting the shafts with respect to a case and restrict movement of the shafts in an axial direction thereof, includes an assembling step of assembling an outer ring of the first rolling bearing and an outer ring of the second rolling bearing to the case in a state where the outer rings are movable in the respective axial directions; and a positioning step of determining axial positions of the first rolling bearing and the second rolling bearing while rotating the first shaft and the second shaft in a state where the first double helical gear and the second double helical gear are meshed with each other, after the assembling step.

A method of joining parts, where at least one of the parts has a faying surface defining grooves therein. One of the parts is formed of a majority of titanium, and the other part is formed of a majority of iron. The method includes providing a set of opposed welding electrodes disposed on a side of each part and applying pressure to and heating the parts via the set of electrodes to form a joint between the parts. A bonded assembly includes a first part formed of a majority of titanium and a second part formed of a steel alloy. The first and second parts having a bond that includes a portion of the first part directly in contact with and attached to a portion of the second part. The parts may be a titanium-containing differential carrier case bonded to a steel gear.

A first abutting surface, a first welding surface, a first facing surface are formed in a differential case. A second abutting surface, a second welding surface, and a second facing surface are formed in a differential ring gear. In an installing step, the first abutting surface and the second abutting surface are inserted, positions of the differential case and the differential ring gear are determined in an axial direction, a separation portion that spaces the first welding surface and the second welding surface away from each other and that has a non-linear portion is formed, and a void is formed between the first facing surface and the second facing surface. In a welding step, a laser is irradiated to the separation portion and the first welding surface and the second welding surface are welded.

A method for assembling an axle assembly for a vehicle including that a pinion gear is inserted into a differential housing. The pinion gear having a first end and a second end opposite the first end. The pinion gear further includes a gear head at the first end, external threads proximate the second end, and external splines located a first distance away from the second end. The method further includes that a flange is slid over the second end of the pinion gear. The flange including internal splines. The method also includes that the internal splines of the flange are engaged with the external splines of the pinion gear and the flange is anchored to prevent the flange and the pinion gear from rotating. The method may further include that ultrasonic sound waves are transmitted through the pinion gear and reflections of the ultrasonic sound waves are detected.

A method of providing limited slip in a differential assembly includes interconnecting an axle and a differential assembly through a first slippable linkage. The axle is driven in rotation with a first housing of the differential assembly operable to be driven in rotation by a ring gear. A plurality of pinion gears of the differential assembly are positioned in the first housing and are driven in rotation by the first housing. A side gear is fixed to the axle and is meshed with at least some of the pinion gears. The axle is operable to slip relative to the first housing. The first housing, the plurality of pinion gears and the side gear are enclosed within a second housing. The axle extends from a first end positioned within both of the first housing and the second housing to a second end positioned outside of both of the first housing and the second housing.

In at least one implementation, a method of assembling gears into a housing of an automotive differential includes, selecting a thickness dimension of first and second pinion gear washers, and first and second side gear washers, locating a pair of pinion gears, a pinion shaft and a pair of side gears at least partially within an interior of the housing with the pinion gear washers between the housing and separate ones of the pinion gears, and the side gear washers between the housing and separate ones of the side gears. The thickness of the side gear washers may be a function of target side gear apex positions and relative to a pinion gear apex axis. The thickness of the pinion gear washers may be a function of target pinion gear apex positions residing along a pinion gear apex axis and relative to a side gear apex axis.

A differential device includes a ring gear receiving a rotational driving force from a drive gear, a differential case rotating integrally with the ring gear around a predetermined axis, and a differential mechanism installed within a barrel part of the differential case. The ring gear includes a gear portion meshing with the drive gear, and a rim portion that is formed integrally with an inner periphery of the gear portion and is fitted, in a non-welded state, onto a maximum diameter outer peripheral portion of the barrel part or a predetermined outer peripheral portion having a smaller diameter than the maximum diameter outer peripheral portion. The rim portion has a to-be-fixed portion welded to the barrel part at a position spaced in an axial direction from a fitting part via which the rim portion and the barrel part are fitted, the position being further radially inward than the fitting part.

A differential device includes a differential gear mechanism having a plurality of differential gears, a plurality of differential gear support bodies supporting the plurality of differential gears, and a pair of output gears meshing with each of the differential gears; and a differential case having a support member having a plurality of opposite ends-supporting parts supporting opposite end parts of each of the differential gear support bodies, a first cover member covering a back face of one of the output gears and capable of being joined to the support member, and a second cover member covering a back face of the other output gear and capable of being joined to the support member, wherein a recess portion facing a back face of each of the differential gears is formed in an outer support part, supporting of the differential gear support body on an outer side of the output gear.