The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 17, 2013
Filed:
May. 09, 2008
Kikuo Maeda, Kuwana, JP;
Kikuo Maeda, Kuwana, JP;
NTN Corporation, Osaka, JP;
Abstract
The invention provides a deep groove ball bearing which exhibits a long life even in a high-temperature environment or an environment involving the penetration of water in spite of its low alloying element content. The outer race, inner race and ball constituting the bearing are made of a steel which contains 0.3 to 0.4% of carbon, 0.3 to 0.7% of silicon, 0.3 to 0.8% of manganese, 0.5 to 1.2% of nickel, 1.6 to 2.5% of chromium, 0.1 to 0.7% of molybdenum and 0.2 to 0.4 of vanadium with the balance consisting of iron and impurities and in a total content of silicon and manganese of 1.0% or below, a total content of nickel and chromium of 2.3% or above and a total content of chromium, molybdenum and vanadium of 3.0% or below. Surface hardened layers are formed in the outer race, inner race and ball respectively and the surface hardened layers exhibit hardness of 725 to 800 HV, while the maximum particle size of carbides dispersed in the surface hardened layers is 10 μm or below and the area ratio thereof is 7 to 25%. Further, the inner parts exhibit hardness of 450 to 650 HV.