Travel Motor

A. Hydraulic Motor Section

1. Motor Housing / Casing

   • Encases motor components; usually cast steel.

2. Piston Assembly

   • Axial piston type (common in final drives). Converts oil pressure into rotational force.

3. Cylinder Block / Barrel

   • Rotates with pistons; central to hydraulic power conversion.

4. Valve Plate / Port Plate

   • Manages fluid flow between pistons and system.

5. Swash Plate / Shaft

   • Controls piston stroke and thus motor displacement.

6. Shaft Seal Kit

   • Prevents oil leakage and protects from contamination.

7. Rotating Group (Motor Shaft)

   • Drives torque into the gearbox.

B. Gearbox (Final Drive) Section

1. Planetary Gear Carrier

   • Contains sun, planet, and ring gears for torque multiplication.

2. Sun Gear

   • Central gear that drives the planet gears.

3. Planet Gears & Shafts

   • Distribute torque; mounted on the carrier.

4. Ring Gear

   • Outer gear meshed with planets; fixed to housing.

5. Carrier Assembly

   • Connects planet gears and outputs motion to final drive.

6. Output Hub / Flange

   • Connects to the machine’s sprockets or track rollers.

7. Gearbox Housing

   • Encloses and protects the gear train.

C. Brake System (Integrated or External)

1. Multi-disc Brake Pack

   • Spring-applied, hydraulically released (SAHR system).

2. Brake Piston & Springs

   • Applies pressure when hydraulic fluid is off (for safety).

3. Brake Plates and Discs

   • Friction components that hold the motor stationary.

4. Brake Control Port

   • For hydraulic brake release signal.

D. Seals, Bearings, and Mounts

1. Main Bearing

   • Large thrust bearing to support load.

2. Floating Seals (Face Seals)

   • Keep dirt out of the planetary gear section.

3. O-Rings & Back-Up Rings

   • Sealing between motor and gearbox housing.

4. Output Shaft Seal

   • Protects against oil leaks and dust ingress.

Common Replaceable Spare Parts

Typical Issues to Monitor

• Travel motor leaking oil? → Likely shaft seal or face seal failure.

• Weak travel or slipping? → Worn brake pack, low pressure, or internal leakage.

• Noisy drive or grinding? → Damaged planetary gears or worn bearings.