PANEL 3311125 - Caterpillar

Primary Power Train Components
Illustration 1 g01357960Transfer of Power from the Engine to the Tracks
The engine is the source of the power that is required to propel the tractor. The mechanical power that is created by the engine is converted into electrical power by the generator. The electrical power is then converted back to mechanical power by electric motors that drive the tracks.The generator produces 480 Volt three-phase Alternating Current (AC). The Alternating Current is sent to the inverter. The Alternating current is converted to 615 Volt Direct Current (DC). The Direct Current (DC) is then inverted back into 480 Volt three-phase Alternating Current (AC). The frequency is controlled in order to control the speed of the motors in the electric drive propulsion module.The propulsion module consists of the following components: two electric motors, a large bull gear, brakes and three planetary gear sets. The two electric motors drive the bull gear. The bull gear drives the planetary carrier of one of the three planetary gear sets. The planetary carrier drives the sun gear. The sun gear is splined to a shaft that runs through the center of the propulsion module. All three sun gears are splined to the center shaft. When the brakes are not applied, the propulsion module supplies the power to the final drives.Each final drive is a combination of single reduction and planetary gear set. The single reduction contains a gear set in order to increase the torque to the planetary gear set. The planetary gear set also increases the torque in the final drive. The sprocket that is located on the final drive meshes with the bushings of the track link assembly. The sprocket drives the track around the idler and around the rollers. The track shoe grousers apply force against the ground. The reaction of the force against the ground moves the machine in the desired direction.