Patent · US Expired

System for hardening gears by induction heating

US4785147A · kind A · utility

25Cited by
8References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 7, 1987
Grant dateNov 15, 1988
Priority date
Expiry dateOct 7, 2007

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC21D9/32
  • WIPO fieldMaterials, metallurgy
  • WIPO sectorChemistry

Abstract

An apparatus for hardening the outwardly facing teeth surfaces of a gear is disclosed. First and second induction heating coils with power sources controlled by an appropriate microprocessor heat the gear when in the first coil at a precisely controlled cycle to generate an unstable, circular band of high temperature positioned radially inwardly from the tips of the gear. Before the band can dissipate, the microprocessor actuates an appropriate drive to locate the gear in the second coil energized by an appropriate power source to impart a high skin temperature to the teeth. A liquid spray quench in the second coil is immediately actuated to effectively quench the gear. By sizing the cycles, the apparatus is thus able to rapidly harden the gear teeth at minimal power levels.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.