Client Requirement
A leading EMS (Electronics Manufacturing Services) provider approached us for a precision motion solution in their newly upgraded PCB assembly line. The robotic arms were responsible for micro-component handling (01005 packages and below), requiring ultra-low backlash and sub-arcminute positioning accuracy. Their existing harmonic drive suffered from wear and increased positioning error after extended use, especially under dynamic load.
Key Specifications Provided by Client:
- Mounting Type: Flange-mounted, hollow shaft output
- Gear Ratio: 80:1
- Backlash: ≤0.5 arcmin
- Rated Torque: 40 Nm
- Protection: IP65
- Duty Cycle: 24/7 operation, high cycle count (>1 million)
- Integrated Encoder Compatibility: Absolute encoder ready
Solution Delivered
Our engineering team developed a custom precision planetary gearbox featuring the following design enhancements:
- Preloaded double-stage planetary configuration, optimizing torque transmission with minimal torsional compliance
- Ultra-fine ground gears (DIN 6 quality) to ensure consistent backlash control
- Zero-backlash preload system using flexible disc springs to compensate for thermal expansion
- Encoder mounting flange with micro-alignment inserts for accurate closed-loop feedback
- Vacuum-compatible lubrication for optional cleanroom environment compatibility
We performed full-system integration tests, simulating 1.5 million motion cycles under operational load, with real-time tracking of deviation margins.
Result & Feedback
The client reported:
- Improved repeatability to within ±3 microns
- Cycle time reduction by 11% due to faster settling time
- No measurable drift after continuous 3-month runtime tests This solution is now a standard component in their high-end SMT line architecture.
