Plastic Helical Gear

Plastic Helical Gear Manufacturer in China — Custom POM & Nylon Helical Gears

Raydafon moulds plastic helical gears in its own factory in Ningbo, China, for OEMs that need a quiet, self-lubricating gear rather than a cut steel one. The gear teeth are formed in the injection mould, so the helix angle, profile and bore position are fixed by the tool rather than by a later machining step — which is why batch-to-batch tooth form stays consistent and why unit cost drops once the tool is running. Typical buyers are small-machinery builders, medical and laboratory equipment makers, appliance and pump manufacturers, and anyone replacing a lubricated metal gear pair with a maintenance-free plastic one.

Standard tooling is the fastest and cheapest route: send the module, tooth count, helix angle, bore and face width, and if the mould exists we quote from stock tooling. Where the geometry is new, we build the tool and mould to your drawing. Related products from the same workshop include the helical gear range in metal for higher torque, the full plastic gear line in spur, worm and internal forms, and spur gears if your drive does not need helical overlap.

Specifications

• Product typeHelical gear (injection moulded)
• Standard moduleM0.1 – M2.0
• MaterialPolyacetal (POM) / Nylon, glass-filled grades on request
• Standard boreØ1.40 / Ø1.90 / Ø2.05 / Ø2.40 / Ø2.55 / Ø2.90 / Ø3.05 mm
• Outer diameterØ10.0 – Ø50.0 mm, up to Ø120 mm on custom tooling
• Face width (L)2.0 – 10.0 mm
• Working temperature−30 °C to +100 °C
• LubricationSelf-lubricating, no grease required in normal duty
• CustomisationModule to M3.0, tooth count, helix angle, bore, hub, keyway, colour

Tolerance and capacity: moulded plastic gears hold a wider tolerance band than cut metal gears, and the exact figures depend on module, wall thickness and material grade. Please state the backlash and centre-distance tolerance your assembly needs at the quotation stage — we will confirm what the tooling can hold, or recommend a cut gear if plastic cannot meet it.

POM or Nylon: Choosing the Right Material

If your torque requirement is beyond what moulded plastic can carry, the honest answer is a cut gear — see our spur gear and helical gear range in metal. We would rather quote the right part than sell a plastic gear that fails in service.

Product Detail

The photographs below show our moulded plastic helical gears: tooth form, hub and bore finish, and the assembled gear set.

Key Advantages

1. 01

   Self-lubricating

   POM and nylon run against each other or against steel without an oil or grease film, so a gearbox that previously needed a lubricant chamber, seals and a service interval can be built maintenance-free.

2. 02

   Quiet transmission

   The helix overlap of a helical tooth engages gradually rather than with a single impact, and the polymer itself damps vibration — measured noise on our gears is about 20% below equivalent spur-gear drives in the same application.

3. 03

   Lower reciprocating weight

   Moulded plastic is far lighter than steel or brass, which cuts the inertia of the driven parts. That matters in hand tools, portable instruments, small positioning mechanisms and other weight-sensitive products.

4. 04

   Corrosion and chemical resistance

   Engineering plastics do not rust and resist most acids, alkalis, detergents and food-contact cleaning agents, so the gear can run in humid, washed-down or mildly corrosive environments where a metal gear would need plating.

5. 05

   Consistent moulded geometry

   Tooth form comes from the mould cavity, so every part in the batch is essentially identical — no cutter wear drift, no run-to-run profile variation, and much less inspection effort for you.

6. 06

   Factory-direct price

   Tool, moulding and inspection all happen under one roof, with no trading margin in between. Unit price is driven by the tooling stage, not by a middle layer.

How a Helical Gear Transmits Torque

A spur gear's teeth meet the mating teeth all at once. A helical gear's teeth are set at an angle to the axis, so contact begins at one end of the tooth and sweeps across to the other, the way a zip closes. Load therefore builds up gradually instead of arriving as an impact, which is the main reason a helical pair runs smoother and quieter than a spur pair at the same speed and load.

The second effect is load sharing. Because several teeth are in contact at any moment along that diagonal line, the force needed to transmit a given torque is spread over a larger area of tooth flank, so local contact pressure is lower and surface wear is slower. A single plastic tooth carrying the whole load would deform; a set of teeth sharing it does not — which is exactly why helical geometry suits relatively soft materials such as POM and nylon.

Helical teeth also produce an axial thrust load along the shaft, so the bearings or thrust washers on the shaft must be able to take it. That is the one design point worth checking before specifying a helical gear in place of a spur gear: the tooth overlap buys quietness and load sharing, but it hands an extra axial force to the rest of the assembly.

Applications

• Small gearmotorsQuiet reduction stages
• Medical & laboratory devicesClean, lubrication-free drives
• Food & beverage equipmentWash-down, chemically resistant parts
• Office & home appliancesLow-noise actuation and timers
• Automotive accessoriesMirrors, seats, latches, small actuators
• Instrumentation & roboticsLight, low-inertia positioning drives
• Vending & dispensing machinesSelf-lubricating long-life mechanisms
• Pumps & valvesNon-rusting internal gearing

If your application is not listed, send the drawing or the sample part. In most cases we can confirm from the module, bore and helix angle whether standard tooling fits or a new mould is needed.

Buyer FAQ

• Are these gears moulded or machined from plastic bar?They are injection moulded in steel tooling, which is what keeps tooth geometry identical across the batch and brings the unit cost down. Machined plastic gears are available for prototypes and very low volumes.
• What is the maximum torque a plastic helical gear can carry?It depends on module, face width, tooth count and material grade, so we do not publish a single figure. Send the torque, speed and duty cycle and we will recommend a module and material, or tell you if the duty needs a metal gear instead.
• Do I need to lubricate the gear?No in normal duty. POM and nylon are self-lubricating. For high-speed or high-load continuous running, a small amount of compatible grease can extend life, and we will say so at quotation stage if your duty needs it.
• What tolerances can you hold on bore and tooth form?Moulded parts hold a wider band than cut gears. Tell us the centre-distance and backlash tolerance your assembly needs and we will confirm whether the tooling can meet it, or quote a machined part if it cannot.
• What is the tooling cost and lead time for a custom gear?Tooling cost depends on module, number of cavities and gear size; larger modules and multi-cavity tools cost more. Once the drawing is approved, we confirm the tool lead time and sample schedule with the quotation, normally within 24 hours of receiving the drawing.
• Can you match a sample part we already use?Yes. Send a sample or a dimensioned drawing — module, tooth count, helix angle, bore, face width and material. We will confirm whether it matches existing tooling or needs a new mould, and quote either way.

Related Products and Further Reading

• Precision gear — the full range of transmission gears made in the same factory.
• Helical gear — metal helical gears for duties beyond what moulded plastic can carry.
• Plastic gear — spur, worm and internal plastic gears from the same moulding workshop.
• Spur gear — the alternative when your drive does not need helical tooth overlap.