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Patent Searching and Data

Document Type and Number:
WIPO Patent Application WO/2017/203914
Kind Code:
This race production method comprises a step for obtaining a race by heating a steel (2) to a temperature equal to or higher than the A1 transition temperature at a forming table (3), and punching a portion of the steel (2) in a ring shape, and then hardening the ring-shaped steel (2) at the forming table. In the step for obtaining a race, the heating and punching are performed while tension is being applied to a first portion and a second portion of the steel (2) that are situated away from each other in at least one direction along the surface of the steel (2) with the forming table (3) being situated in the space delineated therebetween. Tension is applied so as to widen the section between the first and second portions of the steel (2) by a length that corresponds to an amount of thermal expansion taking place in the section between the first and second portions when the steel (2) is heated to the abovementioned temperature during the step for obtaining a race. The forming table (3) comprises a first die (30) for punching out the steel (2) and a second die (36) facing the first die (30), wherein a forming surface of the first die (30) or the second die (31, 32) has an indented curved surface (35A).

MIZUTA, Kohei (105 Hidamarinooka 5-chome, Kuwana-sh, Mie 67, 〒5110867, JP)
OHKI, Chikara (105 Hidamarinooka 5-chome, Kuwana-sh, Mie 67, 〒5110867, JP)
FUJIWARA, Hiroki (105 Hidamarinooka 5-chome, Kuwana-sh, Mie 67, 〒5110867, JP)
Application Number:
Publication Date:
November 30, 2017
Filing Date:
April 24, 2017
Export Citation:
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NTN CORPORATION (3-17, Kyomachibori 1-chome Nishi-ku, Osaka-sh, Osaka 03, 〒5500003, JP)
International Classes:
B21D28/00; B21D28/02; B21D37/16; B21D53/10; B21J1/06; B21J5/00; B21J5/08; C21D1/18; C21D9/00; C21D9/40; F16C33/62; F16C33/64
Domestic Patent References:
Foreign References:
Attorney, Agent or Firm:
FUKAMI PATENT OFFICE, P.C. (Nakanoshima Central Tower, 2-7 Nakanoshima 2-chome, Kita-ku, Osaka-sh, Osaka 05, 〒5300005, JP)
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