Manual Transmission Design and Application for Improved Fuel Economy and Efficiency

摘要

In an engine, maximum power is developed at high speed and over a narrow speed range, and the power drops linearly with engine speed. It is desirable to have near-maximum power available at all vehicle speeds for best acceleration and performance. Therefore, a device complementary to the engine is required that takes its power and supplies at its maximum to the vehicle at all road speeds and conditions. The major function of this device is clearly that of an intermediary between the engine and the wheels. It lets the engine run at the speed of its maximum power output at any vehicle speed, and at the same time transmits as much of this power as possible in a manner satisfactory to the performance requirements. Hence, this device is appropriately called the transmission and it is normally attached directly to the engine. Since transmission plays a unique role in the scheme of vehicle performance, the operating efficiency of the transmission is a significant factor that must be quantified in conjunction with the performance objectives and fuel economy requirements. Automobile transmissions in the modern age are divided into the following categories: 1. Automatic - The various forward gear ratios are automatically selected, while neutral and reverse are manually selected by the driver. 2. Manual - The various forward gear ratios, and reverse gear ratio, are manually selected by the driver.