W Series Worm Gear Reducer_0025_01

WK Series (WK / FCWK) Worm Gear Reducer

The WK series represents the W family’s widest range of hollow-shaft units—featuring a through input shaft (WK) or IEC flange (FCWK), W-class housing geometry, and bore diameters ranging from Ø20 to Ø85 mm; the series covers sizes 50 through 200, with the Ø85 mm bore diameter available on size 200 units.

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Description

The WK Series worm gear reducer is the W family’s widest-range hollow bore unit — extending shaft-mount hollow bore worm reduction from size 50 all the way to size 200, with output bore diameters from Ø20 mm to Ø85 mm and a housing geometry drawn directly from the W series’ proven dimensional convention. The WK maintains the W series’ through-shaft solid input accessible from both housing sides, while the FCWK variant replaces that through-shaft with an IEC B5 motor-mounting flange — allowing either motor configuration to be specified against the same hollow bore output geometry. At size 200, the WK reaches output bore Ø85 mm with bore depths of 420 mm — the deepest, largest-diameter hollow bore available in the W family and substantially beyond the Ø70 mm maximum that the WA/WS series provides at equivalent frame sizes. For Australian manufacturers, OEM machine builders, and maintenance engineers across Sydney, Melbourne, Brisbane, Perth, and Adelaide who require W-series hollow bore capacity at frames above size 155 — or who need larger bore diameters at any frame — the WK and FCWK are the only W-family hollow bore units that deliver both. Manufactured to ISO 9001:2015, designed per AGMA 6034, and supplied by Ever-Power Worm Gear Reducer Co., Ltd. (Australia), 27 Harley Crescent, Condell Park NSW 2200.


WK FCWK worm reducer product range from size 50 to 200
WK FCWK worm reducer IEC flange input and hollow bore output detail

Key Specifications & Parameters — WK Series (WK and FCWK Variants)

WK — Through-Shaft Input

Solid input shaft extends from both housing faces — motor couples via jaw coupling to either side. Unused side fitted with blanking cap per AS 4024.1. W-class hollow bore output. Sizes 50–200.

FCWK — IEC Flange Input

IEC B5 motor flange replaces through-shaft input — motor bolts directly to flange face without coupling. W-class hollow bore output unchanged. No input coupling required. Sizes 50–200.

All parameters per ISO 9001:2015, AGMA 6034, and DIN 3975. Bore tolerance H7/DIN 286.

Size Ratio Centre Dist. A (mm) Hub Width B (mm) Overall Length AC (mm) Height H (mm) Input Stub HL (mm) Input Shaft Ø (mm) Output Bore Ø (mm) Weight (kg)
50 10:1–60:1 175 107 115 150 35 30 Ø20 6
60 10:1–60:1 195 117 126 177 42 40 Ø25 8.5
70 10:1–60:1 234 131 155 215 55 40 Ø30 12.5
80 10:1–60:1 264 144 174 250 65 50 Ø35 20
100 10:1–60:1 322 175 224 310 80 50 Ø40 33
120 10:1–60:1 385 200 264 370 95 65 Ø45 50
135 10:1–60:1 435 212 304 425 105 75 Ø60 77
155 10:1–60:1 494 312 330 461 103 85 Ø70 100
175 10:1–60:1 548 334 370 521 123 85 Ø80 140
200 10:1–60:1 688 346 420 575 130 95 Ø85 200

What Is the WK Series and Why Does It Extend to Size 200?

WK Series worm reducer W-class housing hollow bore large size range

The WK is the W family’s hollow bore unit that uses the full W series housing geometry — the same housing that the standard W series solid-shaft unit uses, with its characteristic taller housing profile, larger output shaft section (in the form of the hollow bore hub), and the wider bearing span that gives the W series higher overhung load capacity than the WP series at equivalent centre distances. This distinguishes the WK from the WA/WS series, which while also being W family hollow bore units, use a housing geometry more closely aligned with the WP/WPKA convention.

The most significant practical distinction is size 200: the WK extends to size 200 with a Ø85 mm output bore and a 200 kg housing — well beyond the WA/WS maximum of size 200 at Ø70 mm. At size 175–200, the WK provides bore diameters (Ø80–Ø85 mm) that are simply not available in any other W-family hollow bore configuration and are required for the large-diameter shaft-mount applications found in Australian mineral processing rotary drum drives, large material handling trommels, and heavy conveyor head shafts in mining and agricultural bulk handling.

The FCWK variant adds the IEC B5 motor-mounting flange on the input side — the same flange-and-housing approach used in the FCWD — eliminating the input coupling from the WK drive train. This allows IEC-frame motors to bolt directly to the FCWK without alignment, motor bases, or coupling guards, while the W-class hollow bore output is unchanged.

WK vs WA/WS — When to Specify Which W Family Hollow Bore Unit

Feature WA Series WS Series WK Series
Max bore Ø Ø70 mm (size 200) Ø70 mm (size 200) Ø85 mm (size 200)
Bore Ø at size 135 Ø55 mm Ø55 mm Ø60 mm
Housing geometry WA/WS convention WA/WS convention W series (taller, heavier)
IEC flange variant FCWDA FCWDS FCWK
Best for Standard smooth loads, WA-convention machines Shock loads, WS-convention machines Large bore (Ø60–Ø85 mm), W-class housing, large frames

How to Select WK or FCWK — Selection Guide for Australian Engineers

  1. Choose WK When: (a) driven shaft diameter exceeds the WA/WS maximum bore Ø at your frame size; (b) the machine requires W-series full-depth housing geometry; (c) frame size 175 or 200 is required and hollow bore output is needed; or (d) you are replacing an existing WK unit in legacy machinery.
  2. WK (Coupling Input) or FCWK (IEC Flange)? Specify FCWK when an IEC-frame motor is available and direct motor mount is preferred — eliminating the input coupling, motor base, and alignment procedure. Specify WK when through-shaft input from either side is a functional requirement (secondary encoder, hand-wheel, or second motor on the opposite stub).
  3. Calculate Torque and Frame Size: WK/FCWK rated torques follow the W series convention at each frame size. Apply service factor (SF 1.25–2.0) and select the smallest WK frame whose rated output torque ≥ design torque.
  4. Confirm Bore Diameter: Standard WK bore diameters are listed in the spec table. For driven shafts outside these standard dimensions, custom boring is available on a 2–3 week lead time — specify at order time.
  5. Guard Unused Input Stub (WK): The unused through-shaft stub must be guarded per AS 4024.1 before commissioning. Stub shaft cover plates for W series (not WP series) bolt patterns are stocked for all WK frame sizes.

Accessories We Also Supply: Through-shaft stub cover plates (AS 4024), W-family torque arm kits (WK/FCWK specific), shrink disc assemblies (Ø35+ bores), DIN 6885 parallel keys (all standard sizes), replacement oil seals, and jaw couplings for WK through-shaft input diameters. Contact Ever-Power Australia.

WK and FCWK Applications in Australian Industry

  • Large Rotary Drum Shaft Drives (WA Mining, QLD Processing): WK 175–200 on rotary drum and trommel trunnion shafts where bore diameter requirements (Ø80–Ø85 mm) exceed what any WA/WS unit provides and the W-series housing geometry and higher bearing span are required for sustained radial loads. FCWK variant where IEC motor direct mount simplifies maintenance in the confined overhead positions common in mineral processing drum installations.
  • Heavy Conveyor Head Shaft Drives (QLD, NSW, WA): WK 135–155 on bulk handling conveyor head shafts with large-diameter driven shafts (Ø60–Ø70 mm) in Australian grain receival, minerals processing, and quarry operations where the WA/WS bore would be too small and the WPKS bore diameter (WP convention) does not match the existing shaft.
  • Agricultural Auger and Feeder Shaft Drives (Regional QLD, NSW, SA, WA): WK 80–120 on grain and fertiliser auger shaft drives where the W-series housing geometry is specified and bore diameters at Ø35–Ø45 mm with the W-class housing depth provides better shaft engagement than equivalent WA/WS units at the same frame size.
  • Legacy WK Machine Replacement (All Australian States): The WK and FCWK provide direct dimensional replacement for existing WK units in Australian food, packaging, material handling, and agricultural machinery — maintaining W-series housing dimensions, bore diameters, and torque arm attachment points while optionally upgrading the input from through-shaft coupling (WK) to IEC motor flange (FCWK).

What Australian Customers Say About the WK Series

★★★★★

“WK 175 on our WA mineral processing drum drive — needed Ø80 mm bore and 140 kg W-class housing. No other W family hollow bore unit goes to Ø80 at this frame size. Ever-Power had it in stock and delivered in 11 days to the Pilbara. Exactly the unit we needed.”

— Darren M., Maintenance Engineer, Pilbara WA

★★★★★

“FCWK 120 on our Brisbane grain conveyor head shaft drive. IEC 112B5 brake motor flanges directly, Ø45 mm shaft goes into the bore. The W-class housing height fits our machine envelope perfectly — WP family units are shorter and wouldn’t have cleared the machine frame. 18 months without issue.”

— Nathan C., Conveyor Engineer, Brisbane QLD

★★★★☆

“WK 135 replacing an old unit in our Sydney food plant. Exact dimensional match — same bore diameter, same torque arm holes, same mounting footprint. We needed Ø60 bore which WA/WS couldn’t provide at size 135 (their max is Ø55). Good product; 4 stars because size 135 needed 12 days when sizes 100/120 were in stock same day.”

— Alice N., Plant Manager, Sydney NSW

★★★★★

“FCWK 155 on our agricultural trommel shaft in SA. Size 155 with Ø70 bore and IEC 132B5 motor direct mount. The W-series housing is taller than WP equivalents so it fits the machine base perfectly. No coupling, no motor base, no alignment — just bolt the motor on and slide the shaft in.”

— Marcus L., Agricultural Engineer, Riverland SA

Why Choose Ever-Power for WK Series Worm Reducers in Australia?

Ever-Power Worm Gear Reducer Co., Ltd. (Australia) at 27 Harley Crescent, Condell Park NSW 2200 is one of the few Australian suppliers maintaining stock of WK units across all ten frame sizes including 175 and 200 — sizes that most competitors carry on order only. Our engineering team provides free WK vs WA/WS bore diameter and housing geometry comparisons, and WK vs FCWK input configuration recommendations. Visit About Us and technical reference at worm-gearbox.top.

Frequently Asked Questions — WK Series (WK / FCWK)

1. What is the key difference between WK and WA — both are W family hollow bore units?+
The WK uses the standard W series housing geometry — the same taller, heavier housing that the W solid-shaft unit uses. The WA uses a housing geometry more aligned with the WP/WPKA convention (shorter, lighter). At the same frame size number (e.g., size 135): WA bore Ø = 55 mm; WK bore Ø = 60 mm — the WK provides a 5 mm larger bore diameter, corresponding to the W-class housing’s larger hub capacity. WK also extends to size 200 (Ø85 mm bore) while WA/WS maximum bore is Ø70 mm. Choose WK when the W-class housing geometry is required (for legacy machine dimensional compatibility or the larger bore diameter) and WA/WS when the WA/WS convention housing dimensions are adequate.
2. For WK 200 (Ø85 mm bore, 200 kg), what is the installation procedure?+
At 200 kg, the WK 200 requires mechanical lifting equipment (crane or forklift with spreader bar) for installation — the unit is too heavy for manual handling. Installation sequence: (1) prepare the driven shaft with keyway and anti-fretting compound; (2) suspend the WK 200 with lifting slings attached to the designated housing lifting lugs (not the input shaft or output bore face); (3) slide the housing axially onto the driven shaft in one controlled movement; (4) torque the bore setscrews or install the shrink disc to specification; (5) install the torque arm and connect to machine frame; (6) connect motor coupling or (for FCWK 200) bolt IEC motor to flange. For sites without overhead lifting equipment, request installation supervision from Ever-Power’s technical team.
3. Is a shrink disc available for WK 200 bore (Ø85 mm)?+
Yes — a shrink disc for the WK 200 Ø85 mm bore is available as a custom order item with a 3–4 week lead time. At this bore size, the shrink disc torque capacity is substantial (typically 4,000–6,000 N·m depending on the disc design) — well in excess of most WK 200 application torques. Using a shrink disc on the WK 200 is strongly recommended for rotary drum and large trommel drives where shaft-bore fretting under sustained shock loading is the primary life-limiting failure mode. Provide the driven shaft diameter (must be ≤ Ø85 mm) and required engagement length when ordering.
4. Can FCWK replace an existing WK unit by simply changing the motor input?+
Not directly — the WK and FCWK share the same bore output geometry and housing outer dimensions, but the input face is machined differently: WK has a shaft extension; FCWK has a machined IEC B5 flange face. These are manufactured as separate items — a WK cannot be field-converted to FCWK by changing only the input shaft. When planning an upgrade from WK (coupling input) to FCWK (IEC flange input) on an existing installation, order the complete FCWK unit as the replacement. The output bore, torque arm attachment, and foot-mount dimensions remain unchanged between WK and FCWK at the same frame size — only the input face changes — so all driven shaft and mounting arrangements are preserved when you install the FCWK as a WK replacement.
5. What oil should be used in WK 200 for continuous operation in hot Australian environments?+
For WK 200 in continuous operation at ambient temperatures above 35 °C (common in QLD, WA, and NT summer conditions), specify synthetic PAO ISO VG 220 oil. The larger WK 200 housing provides more oil sump volume than smaller frames, which assists heat dissipation — but at 200 kg and full rated output, the thermal load at sustained 40–45 °C ambient is significant. Synthetic PAO oil provides: (1) higher viscosity index (stays thicker at operating temperature, maintaining film thickness); (2) lower coefficient of friction (reduces heat generation at the worm mesh); (3) better high-temperature oxidation resistance (5,000-hour oil change interval vs 2,500 hours for mineral oil). Change oil at 5,000 hours (synthetic) or 2,500 hours (mineral), and inspect oil colour — darkening above caramel-brown indicates thermal oxidation and the need for immediate oil change regardless of interval.

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