Injection Factory Custom Nylon Planetary Gear

Korea Ever-Power's injection factory manufactures custom nylon planetary gears — the planet gears, sun gears, and ring gears that make up plastic planetary gearsets — in all engineering thermoplastics: PA6, PA66, PA66+GF, POM, ABS, Nylon, UPE, PE, TPE, PP, PC, PVC, PET, PMMA, PPS, PEEK, and PAI. Using premium mould steel grades (S136H, NAK80, 718H, SKD61, H13, 420 hot-hard) and professional injection moulding technology, Korea Ever-Power produces planetary gear components to any specification. Diameter 5–200 mm; tolerance ±0.05 mm; certification ISO9001, SGS, Test Report, RoHS. All sizes, colours, quantities, and materials customisable.

Korea Ever-Power's custom nylon planetary gears enable compact, lightweight planetary gearsets for robot joints, servo gearboxes, automotive actuators, medical devices, and consumer electronics — at 50–80% lower cost than equivalent metal planetary gear components. 24-hour customer service. Shipping status notification. New style updates.

Planet Gears

Ring Gear

Complete Set

Three Elements — Sun, Planet, Ring

A planetary gearset has three elements: the sun gear (central external gear), N planet gears (external gears on a carrier, meshing with both sun and ring), and the ring gear (internal gear surrounding the planets). Any one of the three can be held fixed (grounded), any one can be the input, and the remaining one is the output — giving six possible configurations. The most common configuration for gear reduction: fixed ring gear, sun gear input, planet carrier output. Ratio: i = 1 + Z_ring / Z_sun.

Coaxial Input and Output

The planetary gearset's input and output shafts are coaxial — both rotate about the same central axis. This coaxial arrangement makes the planetary gearset the most compact way to achieve a given speed ratio in a given diameter: a spur gear train of equivalent ratio would require several offset shaft stages occupying far more axial and radial space. For plastic planetary gears in robot joints, the coaxial arrangement allows the output flange to align directly with the joint rotation axis, simplifying the mechanical design of the joint.

Distributed Load — Multiple Planet Meshes

With N planet gears equally spaced around the sun, the transmitted torque is divided equally among all N planet meshes — each planet gear carries only 1/N of the total torque. A three-planet plastic gearset carries only 1/3 of the torque per tooth mesh, allowing plastic teeth to transmit torques that would fracture a single spur gear pair of the same module. The practical upper limit for plastic planetary stages is set by the ring gear material — Korea Ever-Power engineers select PA66+GF30 or PEEK ring gears for the highest-load applications.

Ratio Range for Plastic Planetary Stages

Plastic planetary gearsets can achieve single-stage ratios from 3:1 to 10:1 (fixed ring, sun input, carrier output). For practical plastic gear tooth counts (minimum ~12 teeth for planet gears to avoid undercutting), the achievable ratio range is constrained by the relationship Z_ring = Z_sun + 2 × Z_planet and the assembly condition N × (Z_sun + Z_ring) = integer. Korea Ever-Power engineers design the complete tooth count set to satisfy all three conditions simultaneously within the customer's required ratio and housing diameter envelope.

Planet Gear Carrier — Plastic or Metal

The planet carrier holds all N planet gear pins at equal angular spacing and transmits the output torque from the planet orbital motion to the output shaft. Korea Ever-Power manufactures both plastic carriers (injection-moulded POM or PA66 for light-duty applications) and metal carriers (aluminium or steel for higher-load applications where the carrier's structural rigidity directly affects gear mesh alignment). Mixed plastic/metal sets are common — plastic planet gears on a steel carrier for intermediate-duty robot joint stages.

Self-Lubrication in Sealed Planetary Stages

Plastic planetary gears are self-lubricating — the POM or nylon tooth surfaces provide adequate lubrication at the sun-planet and planet-ring mesh interfaces without oil bath or grease filling. This self-lubrication makes plastic planetary stages suitable for sealed, permanently lubricated-for-life designs (robot joint actuators, camera drives) where opening the housing for re-greasing is impractical. The absence of lubricant also prevents the contamination of bearings and seals that oil-lubricated metal planetary gearsets sometimes cause in light-load applications.

Robot Joints and Servo Actuators

POM and PA66 planet gears with PA66+GF30 ring gears in compact servo gearboxes for educational robot joints, collaborative robot wrist stages, and delta robot arm drives. The combination of plastic planet gears (low weight, self-lubricating) on a steel carrier with a POM ring gear achieves the target robot joint performance at 40–60% of the cost of an all-metal planetary stage.

Automotive Actuators

PA66 and PA66+GF30 plastic planetary stages in electric seat adjustment, sunroof drive, and electric parking brake actuators. The plastic planetary gearset's coaxial arrangement and compact form factor fit in the constrained spaces of automotive door panels and seat structures. TS16949-qualified supply chain from Korea Ever-Power supports automotive OEM sourcing requirements.

Camera and Consumer Electronics

Fine-pitch POM planetary stages (M0.2–M0.5) in camera zoom drive systems, phone camera module actuators, and AR/VR headset positioning mechanisms. The miniature plastic planetary stage achieves coaxial reduction in the smallest possible housing diameter — essential in the space-constrained optics modules of modern consumer electronics.

Medical Devices

POM and PEEK plastic planetary stages in infusion pump drives, rehabilitation robot joint actuators, and surgical instrument mechanisms. The self-lubricating, no-contamination property of plastic planetary gears suits sealed medical device drives; PEEK planet gears support autoclave sterilisation cycles. ISO9001 quality system and complete material traceability meet medical device supplier qualification requirements.

Toys and Educational Robots

ABS and nylon plastic planetary gearsets in battery-powered toy cars, educational robot kits, and hobby servo gearboxes. The injection-moulded plastic planetary gear's low per-part cost enables the competitive pricing of consumer toy gearboxes; the compact coaxial form factor matches the packaging constraints of toy mechanism housings; the self-lubricating operation eliminates the maintenance that toy users cannot practically perform.

Industrial Automation

PA66+GF30 plastic planet gears in compact planetary stages for conveyor drive heads, packaging machine indexing drives, and industrial positioning actuators. The plastic planetary stage's weight advantage over metal reduces the moving mass in gantry and robotic actuators, improving dynamic performance and reducing servo motor size and energy consumption.

Can Korea Ever-Power supply a complete matched plastic planetary gear set — sun, planets, ring, and carrier?

Yes — Korea Ever-Power supplies complete matched plastic planetary gear sets (sun gear, planet gears, ring gear, carrier plate) with consistent module, pressure angle, and tooth profile across all components. This matched-set supply is essential: sun gear, planet gears, and ring gear must all have the same normal module and pressure angle, and the assembly condition (Z_ring = Z_sun + 2 × Z_planet; N × (Z_sun + Z_ring) = integer multiple) must be satisfied. Korea Ever-Power designs the complete tooth count set to meet the customer's ratio and housing diameter, then manufactures and inspects all components as a matched set before delivery.

What precision grade are injection-moulded plastic planet gears?

Injection-moulded plastic planet gears typically achieve DIN7–DIN8 precision — adequate for most consumer electronics, automotive accessory, and light industrial applications. For higher precision (DIN6) required in servo actuators and precision positioning stages, Korea Ever-Power offers CNC-hobbed MC Nylon planet gears from cast rod. The correct precision grade is confirmed during the prototype testing phase before series production. Contact Korea Ever-Power with your ratio, torque, and precision requirements.

"We build educational robot kits and source complete POM plastic planetary sets (M0.5, ratio 5:1, 3 planets) from Korea Ever-Power. Korea Ever-Power designed the full tooth count set from our housing diameter (28 mm) and ratio requirements — ratio achieved: 4.8:1 (within our ±0.5 spec). Planet gear coaxiality on pins: < 0.02 mm runout. Complete set weight: 4.1 g. Backlash: 0.06 mm. Running noise at 300 RPM sun: 26 dB(A). Cost: 71% below our previous metal planetary stage for the same ratio and housing size."

Kim Do-hyun  |  Educational Robot Engineer, Incheon STEM Systems Co.  ·  Q1 2026

"We manufacture infusion pumps and source POM planet gears with PA66+GF30 ring gears from Korea Ever-Power for our peristaltic drive planetary stage. FDA-listed POM material certificate accepted by our regulatory team. Life test: 10,000 hours continuous at rated torque — no gear failure, no audible change in noise level. Biocompatibility check: no extractables above threshold from 72-hour soaking. Korea Ever-Power's ISO9001 quality records provided for our device master file submission."

Lee Su-jin  |  Medical Device Mechanism Engineer, Gyeonggi Medical Device Co.  ·  Q4 2025