Abstract: An object is to obtain a white ink which is easy to redisperse and is redispersible by being shaken several tens of times with weak force at most, or alternatively, without being shaken. As a solution, a white ink composition is provided which contains 5.0 to 20.0% by mass of a titanium oxide in an ink composition; 3.0 to 60.0 parts by mass of a solid content of alkali-soluble resin relative to 100 parts by mass of a pigment or pigments in the ink composition, wherein building blocks of the alkali-soluble resin are styrene; stearyl acrylate and/or lauryl acrylate; and acrylic acid, and the alkali-soluble resin has a weight-average molecular weight of 10,000 or more, an acid value of 100 mgKOH/g or more, and a glass transition temperature of 50° C. or more; and a surfactant.

Abstract: An opening end of an inboard section includes: an end surface composed of a plane positioned farthest from the center of a differential device in the axial direction and perpendicular to the axial direction; a ledge positioned adjacent to the end surface in the circumferential direction of the opening end and closer to the center than the end surface in the axial direction; and a tapered section in a slope shape formed continuing to the inner diameter side of the ledge at the opening end, slanting toward the inner diameter side of the opening end and approaching the center. Lubricating oil supplied to the opening end of the inboard section flows to the tapered section via the ledge and flows from the tapered section into a spiral groove formed on an inner periphery of the inboard section.

Abstract: An opening end of an inboard section includes: an end surface composed of a plane positioned farthest from the center of a differential device in the axial direction and perpendicular to the axial direction; a ledge positioned adjacent to the end surface in the circumferential direction of the opening end and closer to the center than the end surface in the axial direction; and a tapered section in a slope shape formed continuing to the inner diameter side of the ledge at the opening end, slanting toward the inner diameter side of the opening end and approaching the center. Lubricating oil supplied to the opening end of the inboard section flows to the tapered section via the ledge and flows from the tapered section into a spiral groove formed on an inner periphery of the inboard section.