Worm and Wheel Sets | DIN6 Worm Gearing

Overview: Industrial Worm and Wheel Transmissions

Ever-Power's industrial worm and wheel assemblies are engineered for 90° shaft drives that need a large reduction ratio inside a tight housing. A typical set pairs a C45 steel worm with an aluminium-bronze or tin-bronze wheel, producing reduction ratios from 10:1 up to 300:1 in a single stage — a range that would require two or three stages in a conventional helical gearbox. Because the worm carries a shallow helix and the wheel is cut with a circular-arc tooth profile, the two elements mesh in continuous line contact rather than point contact, giving the drive its characteristic quiet run and high load rating.

The product family covers modules M3, M4, M5, M8 and M12 in the standard catalogue, with non-standard centre distances, tooth counts and bore diameters handled through our engineering-to-order channel. Direct replacements are available for legacy SEW, Sumitomo and Bonfiglioli housings that operate across semiconductor fabs in Icheon, automotive parking systems in Seoul, solar tracker drives in Jeonbuk, and food-line conveyors in Busan. Shipments leave Qingdao every week, with door-to-door delivery to Incheon port usually inside 28 days of PO release.

Technical Specifications and Production Data

The table below is the baseline specification envelope for the industrial worm-and-wheel family. Standard surface treatments, tolerancing bands and accuracy grades cover roughly 85 % of the incoming enquiries from Korean OEMs; the remaining 15 % are custom parameters reverse-engineered from a sample or from a legacy drawing.

A tip from experience: specifying DIN 6 pushes the unit cost up by roughly 25 % over DIN 8, but for machine-tool and metrology applications it is worth it. For conveyor and packaging lines, DIN 8 is normally enough and keeps lead time shorter.

Engineering Highlights

Six design choices are what separate a long-lasting industrial worm drive from one that overheats and wears through its wheel in under 2 000 hours. Our build programme locks each of them in before the first chip is cut.

• ★Large single-stage ratio. From 10:1 to 300:1 inside one 90° stage — the most compact way to hit a high reduction without a planetary add-on.
• ★Line-contact meshing. The worm wheel is cut with a circular-arc profile, so the wheel partly wraps the worm. Load is spread along a line, not a point.
• ★Smooth multi-tooth engagement. Similar to helical gearing, multiple teeth carry load at the same time, which keeps running noise below 62 dB at 1 metre for a typical M5 set.
• ★Self-locking option. When the worm lead angle is smaller than the equivalent friction angle, the drive locks under load. For lift trucks, parking turntables and hoists, this eliminates the need for a separate brake.
• ★Controlled thermal design. Aluminium-bronze wheels shed heat faster than tin-bronze, trading a little sliding-friction behaviour for better continuous thermal performance in 8 × 24 h factory duty.
• ★Correct axial-load bearings. Every worm is supplied with the bearing schedule that handles its axial thrust — ignoring this is the single most common cause of field failures on competitor units.

Typical Application Scenarios in Korean Industry

The worm-and-wheel layout is the default choice whenever a machine designer needs a large reduction, a 90° shaft arrangement, and quiet running inside a compact envelope. Below are five scenarios our Korean customers run every week.

Semiconductor Fab Automation

◆ Wafer-handling tracks and cassette indexers in the Icheon and Pyeongtaek fabs demand DIN 6 accuracy, minimum backlash and clean-room compatible lubrication. Stainless steel worms with PTFE-filled bronze wheels are the usual specification.

Automated Parking Systems

◆ Tower and puzzle-type car parks in Seoul and Busan use self-locking worm sets to hold the pallet in position without energising the motor. A 60:1 set with 5 kN output holds a 2-tonne sedan safely during a power outage.

Solar Tracker Drives

◆ Single-axis PV trackers in Jeonbuk and Jeju rely on large-ratio worm drives — typically 7 200:1 after a secondary spur stage — to keep the panel array moving at 1° per minute against wind load. The self-locking feature holds position when power drops.

Medical and Food Machinery

◆ Packaging and filling lines in the food industry run our polished stainless worms with FDA-grade bronze wheels. The combination is washdown-tolerant and carries certificates for food contact in Korea and Japan.

High-Speed Rail and Aviation Ground Equipment

◆ Baggage-handling conveyors at Incheon International and maintenance-dock hoists used on KTX rolling stock both use medium-module worm-and-wheel pairs for their quiet running and load-holding behaviour.

Installation and Correct Meshing Checklist

A worm-and-wheel set fails early when it is assembled with a wrong centre distance, a mismatched module, or a hand orientation opposite to the worm. The installation sequence below is what our technical desk in Seoul walks customers through on their first shipment.

• ⚙Step 1 — Verify module and pressure angle match. The wheel's transverse module must equal the worm's axial module; pressure angles follow the same rule. Mismatch produces immediate tooth-tip interference.
• ⚙Step 2 — Confirm helix hand. For a 90° shaft arrangement, worm helix hand and wheel helix hand must be identical — both RH or both LH. Reversing one is a common installation mistake.
• ⚙Step 3 — Set the centre distance with a gauge. Use feeler shims or an inspection mandrel; do not rely on the housing bore alone. A 0.05 mm error at the centre distance doubles tooth backlash at M5 module.
• ⚙Step 4 — Apply break-in lubricant. Use GL-5 gear oil for aluminium-bronze wheels or a synthetic PAO-320 for continuous duty. Fill to the middle of the sight glass.
• ⚙Step 5 — Run-in at 50 % load. Four to eight hours of run-in at half load seats the contact pattern. Oil changes out after the first 50 operating hours to clear break-in debris.
• ⚙Step 6 — Inspect the contact pattern. After run-in, the contact mark on the wheel should sit central and cover at least 60 % of the tooth face. If it is biased to one end, shim the worm axially.

Ever-Power vs SEW and Sumitomo: Objective Comparison

The brand names mentioned in this section are the property of their respective owners. Ever-Power products are not counterfeit replacements for SEW-Eurodrive or Sumitomo units — this comparison is provided only to help Korean engineers benchmark their procurement options. We are a manufacturer of equivalent-grade worm-and-wheel components, not a reseller of competitor goods.

The following comparison summarises the typical procurement experience for a 20:1 to 60:1 single-stage worm and worm wheel assembly sourced from the three brands. Accuracy, material and service values come from public catalogues and from our own sales experience supplying Korean OEMs who were previously on SEW or Sumitomo.

The honest takeaway: if the installed base is fully SEW and the customer needs spare parts inside 48 hours, SEW's local stock wins. For new builds where lead time and cost matter — and where the engineering team is specifying the drive rather than just repeating an OEM part number — Ever-Power delivers the same accuracy class at roughly 60 % of the unit price, with a tighter custom-lead-time window.

Why Korean Buyers Work With Ever-Power

• ✔In-house CNC gear hobbing, grinding and heat-treatment lines — no subcontracted critical processes.
• ✔ISO 9001:2015 quality system with sample lot inspection on Mitutoyo CMM and Gleason gear testers.
• ✔Korean-speaking sales engineer in Seoul plus Japanese-speaking engineer in Osaka; drawings reviewed inside 24 hours.
• ✔Weekly sailings via Qingdao and Shanghai into Incheon and Busan — consolidated freight reduces per-unit logistics cost.
• ✔Five-year cooperation with 30 plus tier-1 automotive and semiconductor suppliers across Korea and Japan.

Related Worm Drive Products

The worm-and-wheel component sits inside a wider product family. When a Korean purchasing team decides the drive should be delivered as a finished housing rather than a loose gear pair, the natural next product is a packaged worm gear reducer with input shaft, output flange, oil bath and breather already integrated. Conversely, when the application needs the drive inverted or combined with an electric motor, a gearmotor-format worm gearbox is the usual specification.

Component-level customers typically pair the set with a ground C45 worm shaft, tapered roller bearings sized for the axial thrust, and an FKM oil seal rated for 120 °C. The complete worm gear sets catalogue lists every matched assembly we hold in stock or can ship from tooling inside 25 days.

Frequently Asked Questions

Q: What is the realistic lead time from PO to delivery at Busan port?

Standard catalogue parts in stock ship within 5 business days plus 7 days sea freight, so roughly two weeks door-to-door. Made-to-order sets follow the 25-day production cycle plus freight. For urgent replacement orders, air freight via Incheon cuts transit to 2 – 3 days at higher cost.

Q: Do you carry replacement sets for legacy SEW and Bonfiglioli housings?

Yes, for the most common centre distances (40, 50, 63, 80, 100, 125 mm). Send the housing model number or a photo of the nameplate and we match the gear set without needing the original drawing. Our archive covers more than 300 SEW, Sumitomo and Bonfiglioli housings.

Q: Can you supply a self-locking set for a lift-truck tilt mechanism?

Yes. Self-locking behaviour comes from a single-start worm with a lead angle below the friction angle — typically below 5°. We ship this configuration to Korean materials-handling OEMs every month, usually in a 30:1 to 60:1 ratio band.

Q: What cert package do you provide for food-contact applications?

FDA-compliant bronze wheel material, food-grade NSF H1 lubricant, plus RoHS and REACH statements. A Korean-language summary sheet is supplied on request for submissions to KFDA reviewers.

Q: How do I know whether DIN 6 or DIN 8 is right for my machine?

If the downstream machine needs positioning accuracy better than 0.05° (machine tools, metrology stages, semiconductor handlers), specify DIN 6. If the drive is a conveyor, mixer, packaging line or general factory automation, DIN 8 is normally enough and keeps cost and lead time reasonable.

Q: What is the minimum order quantity for a custom centre distance?

Twenty pieces. We cut custom tooling inserts once and reuse them across repeat orders, so the 20-piece MOQ applies only on the first run — repeat orders can drop as low as 5 pieces.

Q: What lubricant change interval should I plan for?

Typical schedule: first oil change at 50 operating hours (break-in), then every 2 500 hours or annually, whichever comes first. Gearbox running above 85 °C oil-sump temperature needs a tighter 1 500-hour interval and a step up to PAO synthetic oil.

Q: Is on-site technical support available in Korea?

Yes. Our Seoul office can dispatch an engineer within 48 hours for critical failure investigations. Routine technical questions are answered by email in Korean inside one working day.

What Our Customers Say

Lee Jun-ho, Procurement Specialist, Seoul (early 2025)
"We were paying almost triple for the equivalent SEW part for our parking-tower drive. Ever-Power matched the centre distance and DIN 8 accuracy, and the first batch of 40 sets passed inspection on the first try. Six months in, zero field returns. The Seoul sales contact replies in Korean within hours, which made the switch a lot less scary."

Jung Soo-ah, Automation Integrator, Daejeon (mid 2025)
"Ordered 18 sets for a solar tracker rollout in Jeonbuk. The self-locking feature is the reason we picked worm drive over helical. Installation went smoothly thanks to the step-by-step meshing guide they sent ahead of shipment. Oil-sump temperature stabilised around 48 °C in summer — well within design margin."

Takeshi Yamamoto, Plant Engineer, Nagoya (late 2025)
"Needed a replacement for a discontinued Japanese brand on a 2008-vintage packaging line. Sent photos of the broken wheel and two spec sheets — quote arrived in 36 hours, sample in 16 days, production parts in another 22. The new set fitted the original housing with zero modification. Noise level dropped, which was a bonus."

Hwang Chan-woo, Conveyor System OEM Owner, Gyeonggi-do (late 2024)
"Been ordering monthly for fourteen months now. Bulk pricing is fair, and the 25-day bulk lead time is exactly what they promise — I time my customer quotations around it. One shipment arrived two days late because of a Busan port congestion, and they sent the delay notification themselves before I had to chase. That kind of communication is why we keep placing orders."

Oh Ye-rim, Food Machinery Supplier, Incheon (mid 2025)
"FDA bronze wheel with stainless worm, running in a dairy filling station. Required documentation for KFDA review was complete on first delivery — that rarely happens with component imports. Tolerance numbers on the incoming inspection report matched the drawing to within 10 %."

Kang Dae-won, Machine Tool Reseller, Ulsan (early 2026)
"Ordered DIN 6 sets for a precision rotary-table retrofit. Backlash measured at 22 arc-seconds on initial assembly — better than the drawing tolerance. The finish on the bronze wheel was notably cleaner than the competitor we trialed first. Follow-up support on the lubricant choice was helpful, in Korean, and free."