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US5560787A
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Rolling bearing for high-speed rotation at high temperatures
Assignee: NSK Ltd
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Filing: 1995-07-26
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Granted: 1996-10-01
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Expires: 2015-07-26
Abstract
Abstract One of component parts of an inner race, an outer race and rolling elements of a rolling bearing is composed of a bearing material that is prepared by working a high-speed steel, carburizing or carbonitriding the wrought steel in a temperature range from 800° C. to less than 1200° C. and subsequently hardening and tempering the carburized or carbonitrided steel, the steel composing of 0.2 wt %≦C≦2.3 wt %, Si≦1.0 wt %, Mn≦1.0 wt %, 2.0 wt %≦Cr≦7.0 wt %, 1.5 wt %≦W≦22.0 wt %, Mo≦10.0 wt %, 0.5≦V≦6.0 wt %, Co≦18.0 wt %, the balance Fe and incidental impurities. By carburizing or carbonitriding the steel at low temperatures less than 1,200° C., not only high core toughness is insured but also the dissolved C or N in the surface is compensated to increase the hot strength of the steel and the compressive stress that remains in the surface after heat treatment, so that the rolling bearing that rotate at high speed and high temperatures of more 400° C. extends the service life.
Inventors
- 👤 Masaaki Takagi
- 👤 Manabu Ohori
- 👤 Kyozaburo Furumura
- 👤 Kenji Yamamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:12
CPC Classifications
F; F16; F16C; F16C33/00; F16C33/30; F16C33/58; F16C33/62; C; C21; C21D; C21D9/00; C21D9/36; C21D9/40; Y; Y10; Y10S; Y10S148/00; Y10S148/902; Y10S148/906
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
111 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein a surface layer of at least one of said component parts has hardness of the range from 60 to 65 in Rockwell hardness at the temperature of the range from 300° to 400° C.
Claim 2
Dependent Claim
111 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein a surface layer of at least one of said component parts has hardness of the range from 60 to 65 in Rockwell hardness at the temperature of the range from 300° to 400° C.
Claim 3
Dependent Claim
112 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein average residual compressive stress in the neighborhood of a surface of at least one of said component parts is 225 to 400 MPa in the range from the surface to a depth of 2 mm.
Claim 4
Dependent Claim
112 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein average residual compressive stress in the neighborhood of a surface of at least one of said component parts is 225 to 400 MPa in the range from the surface to a depth of 2 mm.
Claim 5
Dependent Claim
97 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein an Izod impact value of a core of at least one of said component parts is 100 to 200 J.
Claim 6
Dependent Claim
97 words
A rolling bearing for high-speed rotation at high temperatures, comprising component parts of an inner race, an outer race and rolling elements, wherein at least one of said component parts is prepared by working a high-speed steel comprising: 0.2 wt %≦C≦2.3 wt %; Si≦1.0 wt %; Mn≦1.0 wt %; 2.0 wt %≦Cr≦7.0 wt %; 1.5 wt %≦W≦22.0 wt %; Mo≦10.0 wt %; 0.5 wt %≦V≦6.0 wt %; Co≦18.0 wt %; the balance Fe and incidental impurities, wherein an Izod impact value of a core of at least one of said component parts is 100 to 200 J.
Claim 7
Dependent Claim
42 words
The rolling bearing of claim 1, wherein average residual compressive stress in the neighborhood of a surface of at least one of said component parts is 225 to 400 MPa in the range from the surface to a depth of 2 mm.
Claim 8
Dependent Claim
27 words
The rolling bearing of claim 1, wherein an Izod impact value of a core of at least one of said component parts is 100 to 200 J.
Claim 9
Dependent Claim
27 words
The rolling bearing of claim 4, wherein an Izod impact value of a core of at least one of said component parts is 100 to 200 J.
Claim 10
Dependent Claim
27 words
The rolling bearing of claim 2, wherein an Izod impact value of a core of at least one of said component parts is 100 to 200 J.
Claim 11
Dependent Claim
40 words
The rolling bearing of claim 1, wherein the steel is subjected to a carburizing and hardening treatment, or a carbonitriding and hardening treatment, at a temperature range from 1050°-1200° C., and then tempering at a temperature range of 500°-600° C.
Claim 12
Dependent Claim
40 words
The rolling bearing of claim 2, wherein the steel is subjected to a carburizing and hardening treatment, or a carbonitriding and hardening treatment, at a temperature range from 1050°-1200° C., and then tempering at a temperature range of 500°-600° C.
Claim 13
Dependent Claim
40 words
The rolling bearing of claim 3, wherein the steel is subjected to a carburizing and hardening treatment, or a carbonitriding and hardening treatment, at a temperature range from 1050°-1200° C., and then tempering at a temperature range of 500°-600° C.
Claim 14
Dependent Claim
32 words
The rolling bearing of claim 1, wherein the steel is subjected to carburizing at a temperature of 930° C. for 8 hours, and then tempering at a temperature range of 500°-600° C.
Claim 15
Dependent Claim
32 words
The rolling bearing of claim 2, wherein the steel is subjected to carburizing at a temperature of 930° C. for 8 hours, and then tempering at a temperature range of 500°-600° C.
Claim 16
Dependent Claim
32 words
The rolling bearing of claim 3, wherein the steel is subjected to carburizing at a temperature of 930° C. for 8 hours, and then tempering at a temperature range of 500°-600° C.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-10-01 | 2000-04-01 | 2000-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-10-01 | 2004-04-01 | 2004-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-10-01 | 2008-04-01 | 2008-10-01 | $7700.00 | Window Closed / Lapsed |