Nsk Corporation

Kikuaki Kamamura

Manabu Ohori

Akihiro Kiuchi

Hiroshi Narai

A toroidal-type continuously variable transmission component, such as an input disk, an output disk, an inner ring of a power roller bearing, and an outer ring of the power roller bearing, which is functioned as a rolling member, has a layer a depth of which is 0.5 mm or less from the surface thereof. The layer does not include a non-metallic inclusion having a maximum diameter of up to 0.1 mm in the area thereof having a depth of 0.5 mm or less from the surface thereof.

Toroidal-type continuously variable transmission component and method for evaluating the same

In an ultrasonic detecting method for a bearing ring in which a bearing ring 2 and an ultrasonic detection probe 3 are disposed within ultrasonic transmission medium such as water, then ultrasonic wave is transmitted from the ultrasonic detection probe 3 to the bearing ring 2, and a defect of the bearing ring 2 is detected on the basis of an ultrasonic wave echo reflected from the bearing ring 2, wherein at least a defect in a range from the surface of the bearing ring 2 to a position beneath by 2 mm from the surface of the bearing ring which is deeper than a maximum shearing stress position of the bearing ring 2 is detected by an angle beam method with an incident angle in a range of 10 to 30.degree., preferably in a range of 25 to 30.degree., and a defect in a range deeper than the range detected by the angle beam method is detected by a normal beam method with an incident angle in a range of 0 to 10.degree., preferably in a range of 0 to 5.degree., thereby to detect a defect in the entire section of the bearing ring 2.

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Nara, Japan

Kikuaki Kamamura