Design of Linear Functional Noncircular Gear with High Contact Ratio Used in Continuously Variable Transmission

Abstract

Continuously variable transmission (CVT) of noncircular gears has the technical advantages of large bearing capacity and high transmission efficiency. This paper focuses on the linear functional noncircular gear pair to realize continuously variable transmission. According to the required working section transmission ratio of noncircular gear pair, the transmission ratio function in the non-working section, was constructed by using polynomial, and then the influence of pitch curve parameters in working section on which in non-working section was also analyzed. Furthermore, the pitch curve of the linear functional noncircular gear pair, which are suitable for transmission, were obtained. In order to improve the stability and bearing capacity of gear transmission, the noncircular gear pair transmission with high contact ratio was designed, and an indirect method to verify the contact ratio by detecting the contact length error of tooth profile was proposed. The error was calculated by comparing the actual contact tooth profile length obtained from the rolling experiment with the accurate value of contact tooth profile length based on the principle of gear and the property of involute profile, and the noncircular gear transmission with high contact ratio was verified.