Nsk Corporation

Shoji Horike

Nobuyuki Hagiwara

Masahiro Yasumura

Chuichi Sato

Dai Kinno

Tsuyoshi Saito

Yuko Kamamura

Takaji Iwasawa

Yuichi Sumita

To avoid a difficulty of inserting a spline shaft into a spline hole, respective holding membersconstituting a holding devicefor holding a hubare displaced in a radial inward direction of a small diameter stepped portion. The inner peripheral surface of the inside end of an original holeis elastically deformed radially inward the same as or slightly greater than the elastic deformation caused by externally securing tightly an inner ring to the small diameter stepped portion. In this condition, a female spline portion for constituting a spline hole is formed in the original hole

Manufacturing method for a drive wheel rolling bearing unit and manufacturing apparatus therefor

In a manufacturing method and a manufacturing apparatus for a wheel-support rolling bearing unit, when forming a crimped portionon an end (inside end) of a hub main body, by rocking die forging using a die, while preventing enlargement of equipment, in order to prevent forming indentations in a second outer racewayand a second inner raceway, in the present invention, the outer ringis turned by a motor, and the ballsare rotated. A difference is provided between the rotation speed of the ballsand an oscillation speed of the die. This difference is preferably at least 10 min. By rotating the ballsthe formation of indentations in the second outer racewayand the second inner racewayis prevented. Moreover, by providing the difference between the rotation speed and the oscillation speed of the die, an increase in the torque required for rotation the outer ringis suppressed.

Manufacturing method and manufacturing apparatus for wheel-support rolling bearing unit

A cylindrical portion formed in the inside end portion of the hub is caulked and spread using a pressing mold assembled to an oscillating/caulking apparatus to thereby form the caulking portion. In working or forming the caulking portion, a cylindrical projecting portion formed in the central portion of the leading end face of the pressing mold is inserted into the cylindrical portion to thereby prevent the inside diameter of the cylindrical portion from reducing excessively.

Method for manufacturing wheel-supporting hub unit and pressing mold for manufacturing same hub unit

When a shape of the cylindrical portion ( ) to be formed into the calking portion ( ) is devised and when a sectional shape of the annular recess portion ( ) of the die ( ) for plastically deforming the cylindrical portion ( ) is devised, the calking portion ( ) is continuously given a compressive average stress during the process of working.

Method of manufacturing hub unit for supporting wheel and die for manufacturing the same

While rotating a spindle the circular hole is worked using a cutting tool Before or after the working operation of the circular hole a chuck is translated in a direction perpendicular to the rotation center axis of the spindle by a slider And, the flat surface as well as the stepped surfaces and inner surfaces which are respectively composed of partially tubular surfaces, are cut or worked.

Trunnion for half-toroidal-type continuously variable transmission and method for working the same

As a ball for ball bearing there is provided a ceramics-coated ball made of a steel having almost the same linear thermal expansion coefficient as that of the bearing ring of the ball bearing and coated with a ceramics material. In this arrangement, even when the temperature during bearing assembly and the working temperature differs from each other, the release of preload or excessive preload can be prevented as in ceramics ball because the bearing and the ball can expand or shrink in the same manner. Further, since the ball and the bearing ring contact with each other via the ceramics layer, fretting abrasion can be prevented, making it possible to obtain excellent running performance and acoustic properties.

Growing community of inventors

Kanagawa, Japan

Shoji Horike