So What’s a CVT and How Does It Work?

What is a CVT?

A continuously variable transmission (CVT) is a transmission that operates on an ingenious pulley system that automatically varies the transmission ratio, allowing an infinite variability between highest and lowest gears with no discrete steps or shifts. CVTs provide more useable power, better fuel economy and a smoother driving experience than traditional transmissions that use gearboxes with fixed numbers of gear sets.

Principle Elements of a CVT:

  • Primary clutch
  • Secondary clutch
  • Belt

The primary clutch is an advanced form of centrifugal clutch and is typically mounted to the output end of the engine crankshaft.  The clutch has two sheave faces; one that is laterally fixed (stationary sheave), and one that can move in and out to engage the belt (moveable sheave).  In most systems, at idle the sheave surfaces are spread at their widest spacing, the belt is riding on the post or shaft at the smallest diameter of the clutch, and the belt is not pinched by the sheave faces.  This provides a “neutral” position that allows the engine to idle without transmitting power to the wheels.

The secondary clutch is mounted to the input shaft of the transmission, transaxle, or the like.  In modern CVT systems such as those used in recreational vehicles, the secondary clutch has two functions:  as a “slave” to the primary clutch and to provide a torque sensing element.

The belt in most CVT systems is a heavy duty “V-belt” which is V-shaped in cross section.  They are made of rubber components reinforced with Kevlar and other materials to enhance durability.

How a CVT Works

TEAM receives a lot of requests to explain how a CVT works. In response, we produced a video, aptly titled, How A CVT Works, to demonstrate the basics of a Continuously Variable Transmission (CVT).  Take a look.

Contact us for more information about TEAM's CVT systems.