The lead screw serves as a core precision transmission component in humanoid robot joints. Residues such as lapping compound, cutting oil, metal fines and polishing dust on the lead screw will accelerate wear and trigger abnormal noises after assembly if not thoroughly cleaned, impairing the robot’s repeat positioning accuracy and service life. Tailored for micro precision lead screws of humanoid robots, Buck ultrasonic cleaning solution balances cleaning power and workpiece protection to meet cleanliness requirements prior to mass assembly.

The complete cleaning line adopts a multi-tank ultrasonic cleaning configuration, covering ultrasonic rough cleaning, fine cleaning, rinsing and hot air drying processes. The tanks are made of 304 stainless steel and equipped with Buck dedicated high-frequency transducers. Compared with conventional low-frequency ultrasound, high-frequency vibration generates finer and gentler cavitation bubbles. It can strip stubborn contaminants from thread roots and raceways without damaging the precision surface and coating of lead screws, preventing micro-pitting caused by impact and preserving the dimensional accuracy of lead screws. Each tank is fitted with a temperature control system to stabilize the cleaning fluid at 40~55℃. Combined with neutral water-based detergent, it efficiently decomposes grease and grinding residues without corroding base materials.

Workpieces are positioned by special tooling and suspended vertically to avoid stacking and collision. A slow lifting and swinging mechanism is integrated during cleaning to boost the flow of cleaning fluid inside thread gaps and flush out metal debris trapped in thread grooves, eliminating blind spots in static cleaning. The high-power ultrasound in the rough cleaning tank removes most oil stains and impurities; the fine cleaning tank enhances cavitation to clear fine dust in raceways. Multi-stage pure water rinsing gradually displaces residual detergent to prevent watermarks, followed by filtered hot air drying with adjustable temperature to avoid oxidation and discoloration of lead screws.

The system is equipped with a filtration and circulation unit to continuously filter metal debris in cleaning fluid, maintain fluid cleanliness, extend service life and reduce consumable costs. Liquid level protection and overheat protection are configured to improve operational safety. After cleaning, lead screws meet assembly cleanliness standards with no oil contamination or residual particles, reducing later joint stalling and abnormal noise failures.

This solution adapts to micro lead screws of various specifications for humanoid robots. It supports small-batch cleaning on standalone machines and can connect to automated production lines for loading and unloading. Compared with traditional manual brushing, Buck ultrasonic cleaning delivers superior consistency and lower labor costs. It penetrates deep into threads to remove contaminants, stably guaranteeing the quality of transmission parts of humanoid robots and satisfying the precision component cleaning demands for mass production.