Press quenching is designed to harden steel gears while minimizing distortion, and the process is especially applied for hardening large diameter thin-wall gears, face gears and bevel gears. The dimensional control aims at maintaining flatness, out-of-round, straightness and consistency of radial size. The press quench tooling and the process design have been mainly experience-based, using a trial and error approach for implementation of new processes, new gear materials and gear configurations.
This paper presents a new approach to repair industrial gears by showing a case study where pressure angle modification is also considered, differently from the past repairing procedures that dealt only with the modification of the profile shift
coefficient. A computer program has been developed to automatically determine the repair alternatives under two goals: minimize the stock removal or maximize gear tooth strength.
Induction hardening is widely used in both the automotive and aerospace gear industries to minimize heat treat distortion and obtain favorable compressive residual stresses for improved fatigue performance. The heating process during induction hardening has a significant effect on the quality of the heat-treated parts. However, the quenching process often receives less attention even though it is equally important.
The proper control of distortion after thermal treatment of powertrain components in the automotive industry is an important measure in ensuring high-quality parts and minimizing subsequent hard machining processes in order to reduce overall production costs.
Heat treating and quenching are arguably the most critical operations in the manufacture of gears. This article examines causes of distortion in heat treating and quenching.
Graded hardening technology has proven over the years to yield very good results when used in the heat treating of carburized gears. It is especially advantageous for smaller companies, subject to higher competitive pressures. Unfortunately, despite the fact that graded hardening is a very well-known method, its use has been limited. We strongly recommend this technology to all of those who need to produce gears with high metallurgical quality.
Could the tip chamfer that manufacturing people usually use on the tips of gear teeth be the cause of vibration in the gear set? The set in question is spur, of 2.25 DP, with 20 degrees pressure angle. The pinion has 14 teeth and the mating gear, 63 teeth. The pinion turns at 535 rpm maximum. Could a chamfer a little over 1/64" cause a vibration problem?
Dear Editor:
In Mr. Yefim Kotlyar's article "Reverse Engineering" in the July/August issue, I found an error in the formula used to calculate the ACL = Actual lead from the ASL = Assumed lead.
