In a differential device in which a differential case has a pair of case half bodies that are mutually adjacently disposed in the axial direction, one case half body has a cutout part that extends in the axial direction while having one end opening on a face opposing the other case half body and that enables a shaft portion of a pinion shaft to be inserted thereinto, the other case half body has a support projecting portion that is fitted into the cutout part in the axial direction, and in an assembled state of the differential device in which the pair of case half bodies are joined to each other, the shaft portion of the pinion shaft inserted into the cutout part is held between the cutout part and the support projecting portion, and the pinion shaft is fixed to the differential case. Such differential device has easy assembly.

A final drive differentially for distributing torque input into a shaft via a differential device to a pair of axles is provided with a ring gear coupled via gearing to the shaft to transmit the torque to the differential device. A housing unitarily includes a main portion supporting the shaft and enclosing the differential device, and a wall portion including a first opening through which one of the axles passes and supporting a first end of the differential device. A cover included a second opening through which the other of the axles passes, and is combined with the housing to support a second end of the differential device, wherein the wall portion, the ring gear, and the shaft are arranged, from the wall portion toward the cover, in an order of the wall portion, the ring gear, and the shaft.

A differential hypoid gear, a pinion gear, and paired hypoid gears formed by a combination thereof are provided. The differential hypoid gear includes a ring-shaped main body and a tooth-forming surface, and has a chemical component composition including C: 0.15-0.30 mass %, Si: 0.55-1.00 mass %, Mn: 0.50-1.20 mass %, Cr: 0.50-1.50 mass %, Al: 0.020-0.080 mass %, B: 0.0005-0.0050 mass %, Ti: 0.01-0.08 mass %, N: 0.0020-0.0100 mass %, Mo: 0.25 mass % or less, and Nb: less than 0.10 mass %, the remainder being Fe and unavoidable impurities. The chemical component composition satisfies Formulae 1 and 2. The differential hypoid gear has a metallographic structure including mainly tempered martensite. A martensite ratio at an inside of a dedendum differs between an end portion of a tooth and a central portion of the tooth within a range of 15% or less. A core hardness of the dedendum at the central portion falls within 350-500 HV.

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 hypoid gear, a pinion gear, and paired hypoid gears formed by a combination thereof are provided. The differential hypoid gear includes a ring-shaped main body and a tooth-forming surface, and has a chemical component composition including C: 0.15-0.30 mass %, Si: 0.55-1.00 mass %, Mn: 0.50-1.20 mass %, Cr: 0.50-1.50 mass %, Al: 0.020-0.080 mass %, B: 0.0005-0.0050 mass %, Ti: 0.01-0.08 mass %, N: 0.0020-0.0100 mass %, Mo: 0.25 mass % or less, and Nb: less than 0.10 mass %, the remainder being Fe and unavoidable impurities. The chemical component composition satisfies Formulae 1 and 2. The differential hypoid gear has a metallographic structure including mainly tempered martensite. A martensite ratio at an inside of a dedendum differs between an end portion of a tooth and a central portion of the tooth within a range of 15% or less. A core hardness of the dedendum at the central portion falls within 350-500 HV.

The present disclosure provides a differential gear to be mounted on a vehicle, including a pair of side gears, at least two pinion gears meshed with the side gears, and a differential case that houses the side gears and the at least two pinion gears. Lubricating oil is supplied to and discharged from the inside of the differential case via an opening portion. The differential case includes at least two seat surfaces formed on the inner peripheral surface of the differential case so as to support the pinion gears, weir portions provided between the adjacent seat surfaces and extending in a direction along the rotational direction of the differential case to connect between the adjacent seat surfaces, and an oil reservoir portion formed on the inner peripheral surface by the weir portions so as to be positioned on the opposite side, in the axial direction of the side gears, of the opening portion from the weir portions. Consequently, it is possible to render the differential gear compact by suppressing a shortage of lubricating oil for a sliding portion well.

The present disclosure provides a differential gear device. The differential gear device includes a differential gear set including a first side gear and a second side gear disposed opposite to each other, and a first planetary gear meshing with the first side gear and the second side gear, the first planetary gear being configured to rotate on its own and to revolve around the first side gear and the second side gear; a first motor connected to the first side gear; a second motor connected to the second side gear; and a slider-crank assembly including a crank, a connecting rod, and a sliding block, both ends of the connecting rod being hinged with the crank and the sliding block respectively, and the crank being connected with the first planetary gear.

A differential assembly including a differential housing, a gear assembly, a shaft, and a ring gear. The differential housing generally includes a peripheral wall, first and second end walls connected to the peripheral wall and spaced apart along a rotational axis so that the peripheral wall and the first and second end walls, in combination, define an internal cavity, a transitional region defined in the differential housing where the second end wall meets the peripheral wall, and a first window formed through the peripheral wall, the transitional region, and/or the second end wall and into the internal cavity, the first window including a central portion and first and second ear portions adjoining the central portion and extending outwardly therefrom. The first window defines a shape when projected perpendicularly onto a first plane including both the rotational axis and a pinion axis, said pinion axis extending perpendicular to the rotational axis.

A differential device is provided in which a differential case is dividedly formed into a pair of case half bodies, wherein the differential case is dividedly formed into a pair of case half bodies that are joined to each other in a state in which open ends thereof oppose each other in an axial direction, an inner peripheral face of at least one case half body is formed by turning while a rotational axis of a material to be machined is made to coincide with the rotational axis, and the one case half body has a wall part in which the position of an outside face thereof is determined so that an oil hole extending between an interior and an exterior of the one case half body is formed by the turning. In such differential device, the oil hole of the case half body is formed without an additional process.

A differential device includes: a differential case; a plurality of pinion shafts supported by the differential case and that is disposed on a first axis and a second axis orthogonal to the first axis; a first pinion gear and a second pinion gear that are each rotatably supported by the plurality of pinion shafts and that are disposed on the first axis, and a third pinion gear and a fourth pinion gear that are each rotatably supported by the plurality of pinion shafts and that are disposed on the second axis; and a first side gear and a second side gear that mesh with the first to fourth pinion gears and that are preloaded toward the first to fourth pinion gears. The number of teeth of the first side gear and second side gear is configured to be the 4N+2 in which N is an integer.