FLANGE 6K2503 - Caterpillar

Illustration 1 g01263365
The propel system contains an electrical portion, a hydraulic portion, and a mechanical portion. The electrical portion contains electronic control modules (ECM), associated input devices, and associated output devices. The hydraulic portion consists of two closed circuit hydrostatic loops. One closed loop is for the front propel circuit and one closed loop is for the rear propel circuit. The mechanical portion contains a planetary final drive unit for each wheel.The front propel hydraulic circuit contains a variable displacement pump and a two-speed motor for each front wheel. The rear propel hydraulic circuit contains a variable displacement pump and a two-speed hydraulic motor for each rear wheel. The front and rear propel circuits are equipped with flow divider valves. These valves provide equal traction to the wheels when the traction control system is engaged. The propel motors transfer power to the corresponding wheels through planetary final drives.Each planetary final drive unit contains a spring-applied, hydraulically released parking brake. The hydrostatic drive systems provide the primary braking method.The electronic control system monitors the machine operating conditions. The ECMs on the machine communicate through Controller Area Network (CAN) lines. The control system determines if an output signal should be sent to the electronic displacement controls (EDCs) on the pump. The system prevents the machine from moving under the following conditions:
The propel lever is out of the NEUTRAL position when the machine is started.
The parking brake switch is in the ON position.
The rotor service switch is in the SERVICE position.The electronic control system is also programmed with load control logic. When the load control system is on, the electronic control system adjusts the propel speed in order to maintain optimum engine speed.