Synthesizing Wear-Resistant Straight Teeth Bevel Gears

Abstract

A method of designing bevel gears is given, allowing to reduce the specific sliding ratio. Specific pressure coefficients are used as an additional evaluation criterion. The mathematical relationship between the criteria used is given. A distinguishing feature of the proposed methodology is the possibility of calculating the gears using an arbitrary coefficient of profile shift for each of the gears. In doing so, the value of the radial gap equal to 0.25 of the module is retained in the gears. The Bevel Gears x64 program is used for calculations. This program was written as part of the ongoing research. As an example, it is shown that a gear with number of pinion teeth z1 = 16 and number of wheel teeth z2 = 20, with the coefficient of profile shift for pinion x1 = 0.7 and for wheel x2 = 0.7, has relatively low and fairly close values of specific sliding ratio |λ1max| = 1.213 and |λ2max| = 1.214 as well as specific pressure ratio ϑ1 = 0.45 and ϑ2 = 0.347. In similar gears (z1 = 16, z2 = 20), designed according to the standard methodology (x1 = 0.17 and x2 = –0.17), the values of the studied indicators were |λ1max| = 3.165, |λ2max| = 2.512, ϑ1 = 0.942, and ϑ2 = 0.572. Reducing specific sliding ratios |λ1max| from 3.165 to 1.213 and |λ2max| from 2.512 to 1.214 will reduce the slippage of tooth dedendum on the pinion and wheel in proportion (2.6 and 2.1 times, respectively). The results show a significant increase of wear-resistance of the designed gears.