Evaluation of Advanced Gear Materials for Gear Boxes and Transmissions
Abstract
Helicopter transmission gear materials are selected mainly for their strength. Sliding behavior is normally improved by hardening the surfaces of the gears. However, pitting and spalling may occur to limit the performance of the transmission, under conditions which are not severe enough to cause tooth breakage. In the search for more reliable gear materials, the VASCO-X2 high hot hardness tool steel had previously demonstrated the capability of carrying 2.40 times the design load for 10 million cycles without evidence of pitting or spalling. Further, there was evidence that the VASCO-X2 test gears developed a protective surface layer on the working tooth under operating loads. The current test program consisted of rotating load tests on gear specimens with a tooth geometry designed to achieve pitting and spalling. VASCO-X2 (.24 carbon) high hot hardness tool steel gears, when tested against basline gears of AISI 9310 (AMS 6260) aircraft gear steel, demonstrated a 30-percent greater load carrying capability. A protective surface layer appeared to form on the VASCO-X2 gears lowering critical temperatures during operation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1970
- Accession Number
- AD0881061
Entities
People
- A. J. Lemanski
- J. P. Albert
Organizations
- Boeing Rotorcraft Systems