Flywheel couplings connect two shafts together while absorbing vibration and shock and providing a steady dampening effect. They are engine components that store energy and angular momentum, while ensuring steady shaft rotation when there is uneven torque. Flywheel couplings are necessary because some types of shafts tend to shift during operation, causing misalignment. Shaft movement is caused by bumps or vibration and it results in parallel, angular or skewed shaft misalignment.
Flywheel couplings and other flexible couplings are used in the transmission and engine of all varieties of vehicles. Flywheel couplings are either one or two piece engine components that are composed of a flange, hub and steel or aluminum housing. They are attached to a rotating shaft and smooth the delivery of the torque from the motor or engine. Flywheel couplings vary in size and weight, depending on the application and intended use.
They are heavy, take up little space and are able to work efficiently and safely in temperatures from -40 to 250°F. They are mainly used within the construction and automotive industries. Construction equipment such as skid steel loaders, aerial lifts, excavators, harvesters, bucket loaders, wheeled loaders and baggage handlers all use flywheel couplings as do aerial lifts, sweepers and power mulchers.
Flywheel couplings need very little change in speed to operate correctly and are designed to carry enough energy to power a car between the firing of each cylinder. In manual transmission, a friction plate is placed between a flywheel coupling and pressure plate. This allows the engine shaft to turn the transmission. The weight and size of flywheels directly correlate with the size and weight of the vehicle. The larger, heavier truck flywheel couplings are heavier so they may store more energy and offer faster acceleration.
There are many different kinds of shaft couplings. The Oldham coupling consists of three components: two hubs and a central plastic disk. It accommodates slight parallel misalignment, while providing almost zero backlash. Backlash is the amount of lost motion due to clearance or slackness when movement is reversed and contact is re-established.
The bellows coupling has two hubs and a thin walled metallic bellows and can accommodate all three types of misalignment. Single beam couplings are usually made of a single piece of aluminum and have a system of spiral cuts that allow it to bend in order to accommodate angular misalignment. Multiple beam couplings consist of two to three overlapping beams that address problems of torsional rigidity.