How Does a Nissan Transmission Work?

by Vee Enne

Nissan automobiles employ a continuously variable transmission, rather than the more traditional gear-based transmissions. Regardless of the technology used, a transmission has the same function. A car's transmission varies the ratio of the speed and power between the engine of the car and its wheels. The transmission gives the driver the ability to use first gear to accelerate, or use third gear to travel at high speeds. Without the transmission, the automobile would only be able to use one gear, which would limit its range considerably.

A commonplace manual automobile transmission uses a system of sets of gears to accomplish its function. Each position of the gear-shift engages a different set of gears, which gives the automobile a different speed to power ratio. An automatic transmission, on the other hand, typically uses a planetary model of gears. In this model, there is only one set of gears, which is used in different combinations in order to achieve the proper ratio. A continuously variable transmission, however, does not use gears at all.

The Nissan transmission is a pulley-based continuously variable transmission. These transmissions have three main parts, in addition to a number of electronic sensors and microprocessors. The first main part of a pulley-based continuously variable transmission is the belt, which can be made of metal or rubber. In addition to the belt, there are two variable input pulleys, and output pulleys in this type of transmission.

When the engine is running, one variable input pulley, called the drive pulley, connects to the engine crankshaft. As the engine runs, energy enters the transmission through this pulley. The output pulley, called the driven pulley, transfers that energy to the driveshaft to create movement.

The location of the pulleys in relation to the belt, also known as the pitch radius, determines the gear. As the pulleys move together, it causes the belt to rise, increasing the pitch radius, which results in a higher gear. When the pulleys move apart, and the belt moves downward, the pitch radius lowers, which results in a lower gear. The variations in gears are infinite, due to the minute graduations in pulley location and belt position. This aspect of the continuously variable transmission allows Nissan to produce cars that operate much more smoothly between speeds.

About the Author

Vee Enne is a U.S. Military Veteran who has been writing professionally since 1993. She writes for Demand Studios in many categories, but prefers health and computer topics. Enne has an associate's degree in information systems, and a bachelor's degree in information technology (IT) from Golden Gate University.