Gear Shift Quality Enhancement Using Sensitivity Analysis

The global automotive industry is growing rapidly in recent years and the market competition has increased drastically. The engines with high torque delivery and deeper transmission ratios has become more and more common for a pleasant drivability experience. In a market highly driven from a comfort and an economic point of view, it is essential to develop a transmission and its components in an optimal way. One of the Unique Selling Point (USP) of a vehicle is the gear shift quality & it is highly important to have an optimum shift quality for an enhanced customer experience. Synchronizer plays a vital role for gear shifting performance in manual gearbox without any shifting assistance. The primary function of a synchronizer is to reduce the RPM difference between two gears before gear shifting with minimum time. Static gear shift quality in vehicle standstill and engine off condition is of utmost importance as the customer evaluates only static gear shift quality in a vehicle showroom before the test drive. A negative first impression on static gear shift quality reduces the customer base for the OEM. This paper discusses the optimization of a manual transmission synchronizer for obtaining a superior shift quality for a product in its development stages. A static gear shift quality problem experienced while shifting from gear 4th to gear 5th was solved using tools of optimization. An objective function was generated using the regression model in Minitab software. The sensitivity analysis of input parameters is studied, and an optimized solution is presented. The optimized solution is validated using physical components to have improved gear shift quality.