Nsk Corporation

Takafumi Yasuhara

Hiroshi Nishizawa

Norihiro Aoki

Koji Takano

Chikara Matsuzawa

Masaru Kuge

Hiromitsu Muraki

A martensitic stainless steel containing, by mass %, C: 0.20% to 0.40%, N: 0.1% or less, Mo: 3% or less, and Cr: 12.0% to 16.0%, such that 0.3%&#x2264;C+N&#x2264;0.4% and a PI value (=Cr+3.3Mo+16N) is 18 or more, with the remainder being substantially Fe and unavoidable impurities is quenched from a temperature of 1,030&#xb0; C. to 1,140&#xb0; C. and subjected to a subzero treatment and tempering so as to obtain a prior austenite crystal grain size of a surface layer of 30 &#x3bc;m to 100 &#x3bc;m and a surface hardness of 58 HRc to 62 HRc.

Manufacturing method of mechanical component using martensitic stainless steel, rotating device, rolling bearing and rolling bearing unit

Two bearings are used to rotatably support the pivot with reference to a fixed shaft. The swing arm is highly precisely fixed to the pivot . The outer diameter of the outer race of the lower bearing is larger than the outer diameter of the outer race of the upper bearing . The end surface of the outer race of the outer race of the lower bearing and the outer periphery of the outer race of the upper ball bearing are used as a reference surface to fix the swing arm . The housing used in the prior art is eliminated from the structure according to the present invention to reduce the number of parts.

Rolling bearing unit

Growing community of inventors

Fujisawa, Japan

Takafumi Yasuhara