自动变速器与驱动桥概述 英文文献加中文翻译.docVIP

AUTOMATIC TRANSMISSION TRANSAXLE OVERVIEWby Kyle McFadden Automatic transmissions are highly complex hyrdomechanical devices. Diagnosing and repairing them requires nothing less than an ASE master mechanic. The automatic transmission provides automated selection of forward gears in a motor vehicle. The automatic transmission is able to select the correct forward gear for efficient engine operation based on vehicle speed, throttle position, and engine load. The automatic transmission components consist of transmission case, torque converter, fluid pump, planetary gear set, clutch packs and/or band assemblies, control valves, transmission mainshaft, extension housing and various small parts. The transmission case is manufactured of cast aluminum. It houses the internal components of the automatic transmission and provides a mounting surface for attachment to the engine block. The torque converter is bolted to a type of flywheel called a flex plate. The flexplate in turn, is bolted to the rear of the crankshaft. The torque converter provides a means to transmit engine power into the transmission. Refer to an auto repair manual for a diagram showing the details of your vehicle’s torque converter assembly. The torque converter is a doughnut shaped device that is filled with fluid. When the engine is running, the torque converter spins, rotating and pressurizing the fluid using internally mounted blades. The spinning fluid rotates a turbine that is connected to the transmission mainshaft. A separate internal set of blades called a stator helps to direct the fluid into the turbine. The operation of the torque converter can be compared to a powered air fan spinning a non powered air fan. The powered fan will generate moving air, directed at the non powered fan blade, causing it to rotate. The powered fan becomes the driving member, while the non powered fan becomes the driven member. If the air is moving slow enough, very little torque is transmitted from th