ROLE OF EDGE CONTACT IN THE PROVISION OF CONTACT STRENGTH OF GEARS

摘要

Contact fracture of heat-treated involute gears in gear sets occurs in a mode of edge scoring by the mechanism of microcutting. We have developed a method for calculating the fracture of a tooth under the conditions of edge scoring and used it to obtain refined temperature and force conditions that appear on the edge of a tooth in the operation of a gear set. Specifically, we have shown that the temperature in the edge attains about 400 deg C. The choice of gear parameters with allowance for the edge contact makes it possible to double the load-carrying capacity of gear sets and to reduce the power losses by a factor of 2-3. The service life of such a gear set can be extended additionally by using high-temperature steels or coatings deposited by methods of chemicothermal treatment, for example, by nitriding.