To provide a touchdown bearing capable of improving seizure resistance and abrasion resistance.
This touchdown bering (an angular ball bearing 7) is provided in a magnetic levitation type turbo-molecular pump having an axial magnetic bearing and a radial magnetic bearing for rotatably supporting a rotor shaft integrally rotating with a rotor vane in a noncontact state, and functions by contact between the rotor shaft, an inner diameter surface 71a of an inner race 71 and an end surface 71b when the axial magnetic bearing and the radial magnetic bearing cannot be controlled. The inner diameter surface 71a of the inner race 71 and the end surface 71b are formed by colliding a spherical or substantially spherical metallic particle, and have a hardening layer S having surface hardness of Hv 700 or more in Vickers hardness, having surface roughness falling within a range og 0.3-1.2 Ram and having the thickness falling within a range of 10-100 m. A lubricating coating film F formed of a solid lubricant is formed on a surface of the hardening layer S.
HOSOYA MASAYUKI
Yoshiaki Naito
Cui Shu Tetsu
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