SHAFT 2447353 - Caterpillar

Control of the Machine Travel
Illustration 1 g00876642
Control of the Machine Travel (Block Diagram)The speed (acceleration / brake) and the direction (forward / reverse) of the machine travel is determined by the position of the propel lever. When the propel lever is moved in the forward position, the machine will move forward. When the propel lever is moved in the reverse position, the machine will move in reverse. When the propel lever is in the neutral position, no machine movement is commanded. The ECM uses the position of the lever to apply current to the solenoid valve (forward EDC) or to the solenoid valve (reverse EDC).The engine propel speed dial sets the maximum speed of the machine. The actual speed of the machine is determined by the movement of the propel lever. When the lever is in neutral, the machine is stopped. As the lever is moved away from neutral, the machine increases speed. When the lever is in the maximum position, the machine moves at the maximum speed that is set by the engine propel speed dial.When the switch (parking brake) is applied, the solenoid valve (parking brake) is de-energized. The brake is applied and the propulsion is stopped.When the switch (parking brake) is released, the brake is released. The propel lever needs to be reset to neutral before propulsion is enabled.When the foot brake is applied, the ECM shuts off the current to the solenoid valve (forward EDC) or to the solenoid valve (reverse EDC).Control of the Machine Speed at High Load
Illustration 2 g00876645
Control of the Machine Speed at High Load (Block Diagram)The ECM determines engine speed by reading the signal from the sensor (engine speed). The engine speed will decrease as the power demands are increased. Power demands are increased by going faster or by reclaiming tougher material. Therefore, when the rotor is engaged and when the machine is moving forward, the engine speed will decrease. If the engine speed decreases below a specific value, the ECM will reduce the desired machine speed. Reducing the machine speed will reduce the power demand, and the engine will not stall.Control of the Steering
Illustration 3 g00876649
Control of the Steering (Block Diagram)There are four steering modes for the machine: REAR steering, CRAB steering, COORDINATED steering and FRONT steering. The mode is determined by the switch (steering mode). The ECM continuously reads the position of the front wheels and rear wheels. The ECM outputs current to the solenoid valves (rear steering) in order to move the rear wheels to the proper position. During REAR steering, the rear wheels are turned by the switch (rear steering). During CRAB steering, the rear wheels will turn in the same direction as the front wheels. During COORDINATED steering, the rear wheels will turn in the opposite direction of the front wheels. During FRONT steering, the rear wheels are moved straight ahead to a calibrated position.Note: The switch (rear steering) is active in all steering modes.Control of the Propel Transmission
Illustration 4 g00876653
Control of the Propel Transmission (Block Diagram)The switch (propel