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:
Jun. 11, 2024
Filed:
Dec. 17, 2020
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Tomohisa Kanazawa, Tsukubamirai, JP;
Mitsuhiro Yoshimoto, Ibaraki-machi, JP;
Norihito Hata, Tsuchiura, JP;
Masao Hayakawa, Tsuchiura, JP;
Susumu Meguro, Tsukuba, JP;
Takanobu Hiroto, Ishioka, JP;
Yoshitaka Matsushita, Tsukuba, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
Abstract
Provided is a reusability determination method for a gear that makes it possible to determine reusability of a gear during or after use to increase the reuse ratio. The reusability determination method for a gear of the present invention includes a step of measuring a content of retained γ phases in the gear, a step of calculating a change rate of the content of the retained γ phases, a step of measuring residual stress applied to the gear, a residual stress ratio calculation step of calculating a residual stress ratio to residual stress in an initial state of the gear, and a reusability determination step of determining whether or not the gear is reusable on the basis of results of the calculation in the retained γ phase change rate calculation step and the residual stress ratio calculation step. In the reusability determination step, it is determined that the gear is reusable where the state of the gear corresponds to a first phase Por a second phase Pfrom among the first phase P, the second phase P, and a third phase P, and it is determined that the gear is not reusable where the state of the gear corresponds to the third phase P.