Induction hardened forged gear and process for preparing same
US6315841A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 31, 1999 |
| Grant date | Nov 13, 2001 |
| Priority date | — |
| Expiry date | Dec 31, 2019 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/25
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Bevel gears having a carbon content of at least about 0.4% by weight, preferably 0.5% by weight are manufactured by a process which includes forging a steel blank having a carbon content of at least 0.4% by weight until a bevel gear precursor having essentially the tooth configuration and dimensions of the desired product gear is obtained, and hardening the teeth of the gear precursor by induction heating without machining of the teeth. The initial forging is precise enough so that no further machining of the teeth is required. This requires forging to a tolerance specified in AGMA class 6. The gear is then induction hardened, first by preheating at a lower frequency, say 10 KHz, then induction heating at a higher frequency, say 50 KHz, in order to obtain a desired hardness profile. The desired hardness profile includes the surface hardness of at least 50, preferably 60, on the Rockwell C scale and a core hardness not over Rockwell C 45, preferably from Rockwell 25 to Rockwell 40. This invention provides a low-cost manufacturing process which is especially suited for differential gears, such as pinion mate gears and side gears, and other non-automotive gears that do not have to car…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.