TM22 final drive 21W-60-22130 PC78 hydraulic excavator travel motor gearbox

This high-precision compact driving device assembly (integrating high-pressure travel motor and planetary gearbox) uses Teijin/Daikin's classic TM03, TM09, TM18, and TM22 transmission series pump types, corresponding to Komatsu's core original part number 21W-60-22130. This final drive assembly is specially designed for Komatsu small and medium-sized core tailless/small rotary hydraulic excavators, perfectly matching 7 to 8-ton core flagship models such as PC78US-6, PC75UU-2, PC78, PC78MR, etc. The product is based on first principles for high power density transmission optimization, ensuring absolute certainty of steering and propulsion torque in narrow operating conditions. The physical dimensions of the product packaging are approximately 390mm × 320mm × 340mm, and the overall net weight is about 45kg. The original factory standard position is connected.

"Extreme cleaning and torque alignment: Before installation, the hydraulic pipe mouth and frame installation surface must be thoroughly cleaned to prevent micrometer sized gravel from entering. All high-strength fastening bolts must be tightened using torque wrenches, strictly following the original factory standard torque for symmetrical and phased cross tightening to prevent local shear stress.

Motor forced oil filling (core avoidance pit): When connecting hydraulic pipelines, they must be absolutely aligned and do not connect the wrong drain pipe (Case Drain). Before starting the engine, clean hydraulic oil must be filled from the air release/oil injection port on the top of the walking motor housing. Dry grinding is strictly prohibited for starting, otherwise the rotating components will undergo physical erosion within 3 seconds of ignition.

Low speed no-load exhaust transition: Support the equipment with a working device to suspend one side of the track, control the motor to run alternately in forward and reverse directions at low speed for 10-15 minutes, exhaust the air inside the hydraulic circuit, and closely monitor the gear meshing sound. Only after confirming that the thermodynamic state is stable can the working load be applied on the ground."