Method of manufacturing laminated ring and heat treatment apparatus for use in such method
US6631542B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 2000 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | May 26, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49798
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A cylindrical drum, which comprises a sheet of maraging steel with welded opposite ends, is severed into a plurality of rings of predetermined width, and the rings are rolled to a predetermined length, after which circumferential lengths of the rings are corrected. The rings are aged by placing the rings into an aging chamber, heating the aging chamber to a predetermined aging temperature, and keeping the rings at the predetermined aging temperature for a predetermined period of time. Thereafter, the rings are nitrided by transferring the rings from the aging chamber into a nitriding chamber which is disposed independently of the aging chamber and has been heated to a predetermined nitriding temperature, while maintaining the rings at the aging temperature, keeping the rings at the nitriding temperature in an atmosphere containing at least an ammonia gas for a predetermined period of time, and cooling the rings. The rings are fitted and stacked together into a laminated ring for use as a belt in transmitting power in a continuously variable transmission.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.