Rolling bearing
AssigneeNsk Ltd.
InventorsHiromichi Takemura, Akihiro Kiuchi, Yasuo Murakami
Life of this patent
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Abstract
An outer ring 2 as a stationary ring is fabricated with an iron-steel material of the following composition. Alloying components contain carbon (C) 0.40 wt % to 1.20 wt %, silicon (Si) and/or aluminum (Al) 0.7 wt % to 2.0 wt %, manganese (Mn) 0.2 wt % to 2.0 wt %, nickel (Ni) 0.1 wt % to 3.0 wt % and chromium (Cr) 3.0 wt % to 9.0 wt %. Cr-equivalent amount shown in the following (1) formula is 9.0 wt % to 17.0 wt %. In the bearing face, the hardness is HRC57 or higher, fine carbides (diameter 50 to 500 nm) are dispersively precipitated, and the maximum diameter of carbide is less than 10 μm. Cr-equivalent amount (%) [Cr]+2[Si]+1.5[Mo]+5[V]+5.5[Al]+1.75[Nb]+1.5[Ti] (1)
Claims18
A rolling bearing comprising:
- a stationary ring;
- a rotary ring;
- and
- a plurality of rolling elements rotatably interposed between said stationary and rotary rings,
- at least said stationary ring is made of an iron-steel material containing alloying components of
- 0.40% to 1.20% by weight of carbon (C);
- 0.7% to 2.0% by weight of at least one of silicon (Si) and aluminum (Al);
- 0.2% to 2.0% by weight of manganese (Mn);
- 0.1% to 3.0% by weight of nickel (Ni) and
- 3.0% to 9.0% by weight of chromium (Cr),
- where Cr-equivalent amount defined by following formula (1) is 9.0 wt % to 17.0 wt %,
- Cr-equivalent amount (%)=[Cr]+2[Si]+1.5[Mo]+5[V] +5.5[Al]+1.75[Nb]+1.5[Ti] (1)
- in the formula, [Cr], [Si], [Mo], [V], [Al], [Nb] and [Ti] show containing percent (wt %) of Cr, Si, Mo, V, Al, Nb and Ti in the iron-steel material, and
- wherein said at least said stationary ring has a rolling surface which is subjected to quenching and tempering and has hardness of HRC 57 or higher.
Dependencies are inferred from the claim text.