Nsk Corporation

Yu Koiwa

Tamotsu Misawa

Sumio Sugita

Naoki Matsuyama

Takaaki Anzai

Masaru Terasaki

A rolling bearing includes an inner ring having an outer surface, an outer ring having an inner surface, a plurality of rolling elements rotatably disposed between the inner ring and the outer ring, and a retainer for retaining the rolling elements. The retainer is made of a resin material and is positioned with respect to the inner surface of the outer ring or the outer surface of the inner ring. The retainer includes a pair of annular portions axially arranged in parallel and a columnar portion coupling the annular portions. Then, the rolling bearing satisfies the following expression:AI=LH/dm&#x2265;0.025LH/dm&#x2265;0.025 mmin which H is a radial length of a section of the annular portion, L is an axial length of the same, and dm is PCD of the rolling element.

Rolling bearing and spindle apparatus for machine tool

A rolling bearing includes an inner ring having an outer surface, an outer ring having an inner surface, a plurality of rolling elements rotatably disposed between the inner ring and the outer ring, and a retainer for retaining the rolling elements. The retainer is made of a resin material and is positioned with respect to the inner surface of the outer ring or the outer surface of the inner ring. The retainer includes a pair of annular portions axially arranged in parallel and a columnar portion coupling the annular portions. Then, the rolling bearing satisfies the following expression: AI&equals;LH /dm&gE;0.025 in which H is a radial length of a section of the annular portion, L is an axial length of the same, and dm is PCD of the rolling element.

A bearing unit is provided, wherein the outer peripheral surface of the inner race extends outward in the axial direction beyond the end surface of the outer race, and is formed such that the diameter of the outer peripheral surface of the inner race increases in the direction toward the rolling elements, such that when lubrication oil is ejected together with air on the outer peripheral surface of the inner race, the lubrication oil moves over the outer peripheral surface due to centrifugal force and is supplied to the rolling elements, making it possible to secure the amount of lubrication oil supplied per unit time to the inside of the bearing, and thus making it possible to reduce wind noise.

Bearing unit

A lubrication system for a rolling bearing comprised of, an inner ring fitted on a shaft rotating at high speed inside a housing, on the outer peripheral surface of which an inner ring raceway is formed; an outer ring fitted into the housing, on the inner peripheral surface of which an outer ring raceway is formed; an outer ring spacer fitted into and supported by the housing adjacent to the outer ring and having a lubrication oil path; and a plurality of rolling elements provided between the inner ring race ay and the outes ring raceway; wherein the lubrication oil is supplied through the lubrication oil path in the outer ring spacer into a space where a plurality of the rolling elements are provided between an outer peripheral surface of the inner ring and an inner peripheral surface of the outer ring, wherein any portion where the sloping direction and/or sloping angle suddenly changes does not exist from the smaller diameter end, to the larger diameter end adjacent to the inner ring raceway.

Growing community of inventors

Fujisawa, Japan

Yu Koiwa