PHV-390-53B Walking/Travel Device Komatsu Caterpillar Yuchai XCMG Takeuchi John Deere 35 40 Travel Motor Travel Reduction Gearbox

Hydraulic travel motors – Provide rotary power to the track wheels.

Dual independent motors – Allow for counter-rotation and pivot turns.

Travel control levers/pedals – Operator inputs for speed and direction.

Main hydraulic pump – Supplies high-pressure oil to the travel system.

Travel control valves – Direct flow from the pump to the left or right motor.

Two-speed travel selection – Switches between high-speed and high-torque modes.

Speed change valve – Alters motor displacement for speed shifting.

Travel reduction gearbox (final drive) – Reduces motor speed and increases torque.

Sprocket drive – Final drive output shaft directly turns the track sprocket.

Planetary gear sets – Inside the reduction gearbox for compact torque multiplication.

Swing bearings – Support the upper structure and allow it to rotate during travel turns.

Track frame – Rigid structure housing the final drive and rollers.

Hydraulic pressure release – Allows the machine to be towed by disengaging the motors.

Travel brakes – Typically spring-applied, hydraulic-release parking brakes.

Hydraulic counterbalance valves – Prevent uncontrolled movement on slopes.

Pilot pressure system – Provides low-pressure control signals to the main valves.

Neutral bypass – Routes pump flow back to tank when travel levers are not activated.

Load sensing system – Adjusts pump flow and pressure based on demand.

Track tension adjustment – Maintains proper tension via grease cylinders.

Track rollers and idlers – Support and guide the track chain.

Pivot turn (spot turn) – Achieved by driving one track forward and the other reverse.

Gradual turn – Accomplished by varying speed between the two tracks.

Straight-line travel – Both motors receive equal flow and pressure.

Auto-deceleration system – Redects engine speed when travel levers are neutral.

Travel alarm – Sounds when the machine is set to move.

Speed sensors (if equipped) – Monitor track speed for control or monitoring systems.

Travel pressure relief valves – Protect the system from overloads.

Case drain lines – Return internal leakage oil from motors back to the tank.

Hydrostatic transmission principle – Uses variable hydraulic flow for infinite speed control.

Integrated pump-motor circuit – Forms a closed-loop for efficient power transfer.