Overview
POM automation gears are precision-machined power transmission components used to transmit motion and torque in robotics, automated assembly equipment, and precision mechanisms. Manufactured from polyoxymethylene (POM), also known as acetal or Delrin, these gears combine high stiffness and strength with low friction, excellent dimensional stability, and good fatigue resistance. The homopolymer and copolymer acetal grades used by OrroMFG machine cleanly to accurate tooth forms, hold tight tolerances, and run smoothly without external lubrication, making them ideal for high-cycle indexing, positioning, and drive applications in automation and office equipment.
POM is valued in automation because it delivers metal-like mechanical performance with the low weight, quiet running, and corrosion resistance of a polymer. Its low moisture absorption keeps gear dimensions stable across humidity changes, preserving backlash and mesh accuracy in precision drives. The material’s low coefficient of friction and self-lubricating behavior reduce wear and noise, extending service life in high-cycle mechanisms and eliminating oil contamination concerns. OrroMFG manufactures POM gears in spur, helical, and internal configurations, with plain, keyed, or bushed bores. Options include glass-filled POM for higher stiffness and load capacity, PTFE-modified POM for reduced friction, and anti-static grades for electronic handling. Every gear is machined to tight tolerances to ensure accurate mesh, uniform tooth contact, and quiet, reliable operation.
Key Features
- High Stiffness and Strength: POM provides metal-like rigidity and load capacity in a lightweight, corrosion-resistant polymer.
- Low Friction and Self-Lubrication: Low coefficient of friction enables lubrication-free operation, reducing wear, noise, and maintenance.
- Excellent Dimensional Stability: Low moisture absorption maintains accurate backlash and tooth mesh across changing humidity.
- Good Fatigue and Wear Resistance: Withstands millions of load cycles in indexing and positioning mechanisms.
- Quiet, Low-Vibration Running: Natural damping absorbs vibration and reduces operating noise in office and automation equipment.
- Machinable to Precision Tolerances: Machines cleanly to accurate spur, helical, and internal tooth forms with fine surface finish.
Material Specifications
| Property | POM Homopolymer (Delrin) | POM Copolymer (Acetal) | 20% Glass-Filled POM | PTFE-Modified POM |
|---|---|---|---|---|
| Density (g/cm³) | 1.41 - 1.43 | 1.40 - 1.42 | 1.50 - 1.56 | 1.42 - 1.48 |
| Tensile Strength (MPa) | 65 - 75 | 60 - 70 | 95 - 115 | 55 - 65 |
| Tensile Modulus (GPa) | 2.8 - 3.2 | 2.6 - 3.0 | 5.5 - 7.0 | 2.4 - 2.8 |
| Flexural Strength (MPa) | 90 - 100 | 85 - 95 | 140 - 160 | 80 - 90 |
| HDT at 1.8 MPa (°C) | 95 - 110 | 90 - 100 | 155 - 165 | 85 - 95 |
| Continuous Service Temp (°C) | 90 - 100 | 85 - 95 | 100 - 115 | 80 - 90 |
| Hardness (Rockwell M) | 88 - 94 | 80 - 88 | 92 - 98 | 78 - 86 |
| Coefficient of Friction | 0.15 - 0.35 | 0.15 - 0.35 | 0.20 - 0.35 | 0.08 - 0.18 |
| Water Absorption (24h, %) | 0.2 - 0.3 | 0.2 - 0.3 | 0.2 - 0.4 | 0.2 - 0.3 |
| Fatigue Strength (MPa, 10⁷ cycles) | 25 - 30 | 22 - 28 | 40 - 48 | 20 - 26 |
| Charpy Impact Strength (kJ/m²) | 8 - 12 | 9 - 14 | 4 - 6 | 7 - 10 |
Applications
Industrial Automation
POM gears drive indexing tables, pick-and-place heads, gripper mechanisms, and synchronized transfer units in automated assembly and robotics. Their low friction and dimensional stability maintain accurate mesh and positioning through millions of cycles, while their lightweight construction reduces inertia and improves dynamic response in fast automated movements.
Office Equipment
POM gears are widely used in printers, copiers, scanners, and paper handling mechanisms, where they drive feed rollers, paper paths, and cartridge assemblies. Their quiet running, self-lubricating behavior, and low cost suit the high-volume, low-noise requirements of office equipment, and their stability prevents backlash drift over long service.
Consumer Electronics
In consumer electronics manufacturing and product mechanisms, POM gears are used in small motor drives, camera and lens actuation, and precision positioning modules. Their clean machining, low particle generation, and anti-static options support handling of sensitive electronic components and assemblies.
Packaging
POM gears drive film transport, web tensioning, sealing, and indexing mechanisms in packaging machinery. Their wear resistance and low friction maintain consistent motion in continuous production, while glass-filled grades provide the added stiffness needed for higher torque transmission.
Medical Devices
POM gears are employed in laboratory automation, diagnostic instruments, and drug delivery and analysis equipment. Their dimensional stability, low noise, and ability to run without lubrication suit clean instrument environments, and medical-grade acetal grades are available where biocompatibility is required.
Operating Conditions
- Temperature Range: -40°C to +100°C (-40°F to +212°F) continuous service; glass-filled grades operate up to +115°C at reduced load
- Load Capacity: Suitable for light-to-medium gear loads; glass-filled grades carry higher torque and tooth loading
- Speed: Effective in high-cycle indexing and continuous rotation at moderate peripheral speeds; low inertia supports rapid start-stop operation
- Lubrication Compatibility: Self-lubricating and normally run dry; compatible with greases and oils where added life or cooling is desired
- Chemical Compatibility: Resistant to fuels, oils, alcohols, and many solvents and cleaning agents; not recommended for strong acids or concentrated alkalis
- Moisture and Humidity: Low moisture absorption maintains dimensional stability and stable backlash in humid environments
- Shock and Vibration: Good impact toughness absorbs shock loads in indexing and reversing drives
- Abrasive Environments: PTFE-modified and glass-filled grades improve wear life in demanding or higher-load applications
Material Comparison
| Material | Strength | Temp Range | Wear Resistance | Cost | Best For |
|---|---|---|---|---|---|
| POM (Acetal / Delrin) | Good | -40 to +100°C | Very Good | Medium | Precision automation gears needing stability and low friction |
| Nylon PA66 | Good | -40 to +120°C | Good | Low | General drives, higher temperature, lower cost |
| PEEK | Excellent | -40 to +260°C | Excellent | Very High | High-temp, chemical, high-load precision drives |
| UHMW-PE | Fair | -200 to +80°C | Excellent | Medium | Low-load, low-friction, high-impact applications |
| Steel | Very High | -40 to +300°C | Excellent | Medium-High | High-torque, high-speed power transmission |
Choose POM gears when:
- Accurate mesh and stable backlash are required over long service life
- Lubrication-free, quiet operation is preferred in automation or office equipment
- Low moisture absorption and dimensional stability are essential
- Lightweight, corrosion-resistant gears are needed to reduce inertia
- Moderate temperature and load conditions apply
- A cost-effective, precisely machined gear is preferred over metal or PEEK
Customization Options
- Material Grades: POM homopolymer (Delrin), POM copolymer (acetal), glass-filled POM, PTFE-modified POM, anti-static/conductive POM, and medical-grade acetal
- Gear Types: Spur, helical, internal, rack, and worm wheel configurations
- Size Range: Module 0.3 to 6 and pitch diameters from 6 mm to 400 mm; custom sizes available
- Bore Options: Plain, keyed, splined, set-screw, and bushed bores finished to customer specification
- Hub Configurations: Solid, webbed, spoked, and extended-hub designs
- Tooth Modifications: Profile correction, tip relief, crowning, and backlash adjustment for specific mesh requirements
- Tolerance Grades: Machined to AGMA 8-10 / DIN 7-9 quality with controlled runout and concentricity
- Surface Finishing: Deburring, tumble polishing, and fine-machined tooth flanks for smooth, quiet engagement
- Inserts and Reinforcements: Metal hub inserts and keyed bushings for higher torque capacity
- Secondary Operations: Keyway broaching, set-screw tapping, drilling, and assembly with shafts and mating gears
Quality Assurance
OrroMFG is committed to producing POM automation gears of consistent precision and reliability. Our ISO 9001:2015 certified facilities combine CNC machining and injection molding with rigorous process control to deliver gears that meet customer drawings and performance specifications. Controlled handling and clean production areas protect components from contamination during manufacturing.
Quality control begins with incoming verification of POM resin grade and certification against material data sheets. In-process inspection includes dimensional checks with coordinate measuring machines (CMM) and optical comparators, tooth profile and pitch verification, bore and keyway measurement, and concentricity and runout evaluation. Finished gears undergo final inspection covering critical dimensions, tooth form, and surface condition, with sampling for wear and functional mesh testing where required. Products are supplied with material certificates (COA), dimensional inspection reports, and full batch traceability, and first article inspection (FAI) reports are available for new or critical parts. This disciplined approach ensures every POM automation gear performs reliably in its intended drive system.
