Description
The SWC-CH is the Long Flex configuration of the welded-yoke universal coupling family — same 22-degree flex angle and same 35CrMo alloy steel construction as the SWC-BH, but with an extended intermediate shaft that bridges wider shaft-centre distances. This variant is the engineering choice when the gearbox output and the driven machine are physically separated by distances that exceed the Standard Flex intermediate length, particularly on long-reach crane drives, paper-making machinery, and certain rolling mill applications with extended spindle requirements.
SWC-CH Specifications and Dimensional Range
The SWC-CH range covers gyration diameters from 100 mm to 550 mm with the same nominal torque ratings as the SWC-BH equivalent sizes. The defining dimensional difference is the Lmin minimum installed length, which is approximately 20 to 30 percent longer than SWC-BH to accommodate the extended telescoping spline shaft. Maximum flex angle is 22 degrees and the trunnion cross specification matches the SWC-BH range — induction-hardened 35CrMo alloy steel with sealed needle bearings.
| Model | Gyration Ø D (mm) | Nominal Torque Tn (kN·m) | Fatigue Tn Tf (kN·m) | Flex Angle β (°) | Bore D₂ (mm) | Lmin (mm) |
|---|---|---|---|---|---|---|
| SWC100CH | 100 | 1.0 | 0.5 | ≤22° | 20–44 | 400 |
| SWC150CH | 150 | 4.0 | 2.0 | ≤22° | 30–65 | 520 |
| SWC200CH | 200 | 15 | 7.5 | ≤22° | 40–95 | 620 |
| SWC250CH | 250 | 32 | 16 | ≤22° | 55–115 | 740 |
| SWC285CH | 285 | 63 | 31.5 | ≤22° | 75–130 | 790 |
| SWC315CH | 315 | 100 | 50 | ≤22° | 85–150 | 860 |
| SWC390CH | 390 | 200 | 100 | ≤22° | 100–175 | 970 |
| SWC440CH | 440 | 315 | 160 | ≤22° | 120–200 | 1050 |
| SWC490CH | 490 | 400 | 200 | ≤22° | 135–220 | 1160 |
| SWC550CH | 550 | 500 | 250 | ≤22° | 150–240 | 1250 |
The extended Lmin dimension shown is the minimum installed length when the telescoping shaft is fully compressed. The maximum installed length adds approximately 100 mm of axial travel, allowing the coupling to accommodate the typical shaft-centre variation caused by thermal growth and foundation movement on long-span installations. Bore tolerances and keyway specifications remain identical to the SWC-BH range.
SWC-CH Long Flex Welding Type Universal Coupling – extended intermediate shaft for wide shaft-centre distances. Ever Power Flange Couplings Australia Ltd.
What Distinguishes the SWC-CH from Other Universal Joint Types
The SWC-CH addresses installations where the SWC-BH Standard Flex variant cannot bridge the required gap between driver and driven machine. Common examples include rolling mill spindles where additional intermediate space accommodates pass-line equipment, paper machine drives with extended press-section roll arrangements, and crane drivelines spanning gearbox-to-wheel distances exceeding 1.5 metres. Selecting the Long Flex variant rather than extending a Standard Flex variant beyond its design length is critical — the splined intermediate shaft must remain engaged within its design travel range to function correctly.
Functionally, the SWC-CH behaves identically to the SWC-BH at any given flex angle. The torque transmission, the bearing loading, and the splined-shaft axial reaction are all the same. The only operational difference is the increased polar moment of inertia of the longer intermediate shaft, which slightly affects the start-up acceleration response in highly dynamic drive applications. For continuous-duty rolling mill and crane installations, this difference is negligible.
Why Length Matters for Splined Shaft Design
The telescoping splined section must remain engaged across the full operating range of axial movement. If the splined male and female sections separate beyond their design overlap, the shaft can lose engagement and the drive can fail catastrophically. Specifying the correct flex variant — Standard, Long, or Short — ensures the spline overlap stays within the safe range across the full operating envelope. The SWC-CH provides additional headroom on this overlap for installations with significant thermal axial growth or foundation movement.
Construction and Material Specification
Material specification matches SWC-BH: 35CrMo alloy steel forging for yokes, intermediate shaft, and trunnion cross. The full quench-and-temper heat treatment cycle is followed by induction hardening on the trunnion journals and spline teeth to HRC 58-64. The extended intermediate shaft uses the same spline geometry as the SWC-BH equivalent size, ensuring trunnion cross and spline parts are interchangeable between Standard and Long Flex variants.
Sealed needle roller bearings are pre-lubricated at assembly with the appropriate grease grade. The yoke-to-shaft weld preparation follows the same procedure as SWC-BH — the only difference is the longer intermediate shaft length between the two yokes. Welding is performed on-site at equipment commissioning using qualified welders and the supplied weld procedure specification.
Bridges wider shaft-centre distances than Standard Flex variants. Lmin approximately 20-30 percent longer than equivalent SWC-BH size, with proportional travel range extension.
Same welded-yoke torsional stiffness as SWC-BH. Eliminates bolt-circle tolerance chain that limits flanged hub stiffness on high-frequency reverse-load applications.
Identical material and heat treatment to SWC-BH for equivalent size. Trunnion cross, bearings, and spline parts interchangeable between Standard and Long Flex variants of the same gyration diameter.
Pre-lubricated at assembly. Lifetime sealing eliminates the periodic re-greasing required by older universal joint designs. Same bearing specification across the SWC welding-type range.
Substantial headroom above typical rolling mill spindle and crane drive operating angles. Same flex angle rating as SWC-BH and SWC-DH variants of equivalent size.
Full material traceability, dimensional inspection records, and heat treatment certificates available on request. Standard inclusion in NSW heavy industry equipment dossier packages.
Industrial Applications Across Heavy Industry
SWC-CH applications mirror SWC-BH applications wherever the installed shaft-centre distance exceeds the Standard Flex envelope. The extended length variant is also the default specification on certain rolling mill installations where the spindle must clear ancillary equipment between the gearbox and the work roll. Crane installations with extended bridge spans also commonly specify Long Flex variants.
Wide-Reach Rolling Mill Spindles
Hot strip mill and plate mill spindles often require extended intermediate shaft lengths to clear roll-cooling water headers, mill housing structural members, or scale-removal equipment positioned between the gearbox output and the work roll. The SWC-CH variant accommodates these layout constraints without compromising on torque rating or torsional stiffness. The Long Flex spindle is also specified on certain reversing roughing mills where the additional length provides operational headroom.
Crane Long-Travel Drives with Wide Bridge Spans
Container handling cranes, port cranes, and steel-mill overhead cranes with bridge spans exceeding 30 metres commonly specify SWC-CH variants on the long-travel drive shafts. The extended intermediate length accommodates the thermal growth of the bridge structure under solar heating and the deflection that occurs under loaded operation. Driving the bridge motors at each end of a wide-span crane requires high torque coupling capability with substantial axial travel — both delivered by the Long Flex configuration.
SWC-CH yoke assembly and extended telescoping spline shaft – designed for wide motor-to-driven-machine separations.
Selecting the Correct SWC-CH Size for Your Drive
When choosing between SWC-CH and SWC-BH, the determining factor is the installed shaft-centre distance and the expected operational axial movement. Measure the dimension from the input shaft end to the output shaft end at the mounted equipment position. Compare this measurement to the Lmin and Lmax values published for the candidate coupling size. The installed dimension must sit between Lmin and Lmax with sufficient headroom for thermal and foundation-settlement movement during operation.
If your shaft-centre distance falls between the Standard Flex (BH) and Long Flex (CH) ranges, the Long Flex variant is the safer choice — operating a Standard Flex coupling at its maximum installed length risks losing spline engagement during thermal cooling. The cost premium for the Long Flex variant is modest compared to the consequence of a failed spline engagement in service.
Installation, Operation, and Maintenance Best Practice
Installation procedure follows the SWC-BH workflow with one additional consideration: the longer intermediate shaft is heavier and requires appropriate lifting support during positioning and welding. Use the supplied lifting eyes — never lift from the trunnion cross or the yoke arms.
The Long Flex variant is heavier and longer than equivalent Standard Flex. Use proper lifting equipment positioned at both yoke ends — do not lift from the trunnion cross or yoke arms, which can damage the bearing housings.
Both shaft ends machined square, free of burrs, prepared for welding. Verify material weldability documentation. Pre-heat per the supplied weld procedure if required for thicker sections.
Slide each yoke onto its shaft to the design position. Apply tack welds to hold each yoke. Verify the trunnion cross rotates smoothly by hand before completing the full circumferential weld.
Before completing the welds, verify the splined intermediate shaft moves through its full axial travel range without binding. Confirm the installed length sits between Lmin and Lmax with headroom for thermal growth.
Run the full circumferential weld at each yoke in multiple passes per the supplied weld procedure. Allow controlled cooling to prevent heat-affected-zone cracking. Post-weld heat treatment per engineering specification if required.
Run at progressively increasing speed up to full operating speed. Monitor vibration, trunnion temperature, and shaft axial position for the first 50 operating hours. Inspect bearings and seals at the first scheduled maintenance interval after commissioning.
OEM Cross-Reference and Order Specification
Cross-reference is available for Voith Turbo extended cardan shafts, Rexnord long-flex universal joint couplings, and SKF extended industrial couplings. Provide our Sydney team with the OEM model code, gyration diameter, nominal torque rating, installed shaft-centre distance, and connection method. We confirm the SWC-CH equivalent and any dimensional differences before order confirmation.
Custom intermediate shaft lengths beyond the standard SWC-CH offering are available from our Sydney engineering team. For installations requiring specific axial travel ranges, specific spline pitch, or specific yoke geometry, the standard production lead time applies — typically 3 to 6 weeks for non-standard length variants depending on the size class and current capacity.
Why Choose Ever Power Australia
Ever Power Flange Couplings Australia Ltd. supplies the SWC-CH Long Flex range from our Sydney warehouse as a regular stock item across the commonly specified size classes. Custom intermediate shaft lengths for retrofit applications are handled by our in-house engineering team without the lead time penalty of overseas supply chains. Cross-reference work for Voith, Rexnord, SKF, and GKN extended cardan shaft equivalents is included as a standard service.
Ever Power manufacturing facility — ISO 9001 certified, 12,000 m², 108 dedicated coupling machines, 20+ years of production experience.
Every order placed with our Sydney team is backed by full material traceability, dimensional inspection certificates on request, and direct access to the engineers who specified, machined, and packed your coupling. We do not subcontract technical support — when you phone +61 2 9708 3322 during NSW business hours, you reach the people who actually know the product.
Frequently Asked Questions
Quick answers from our Sydney technical team. Contact us for application-specific guidance.
1. When should I specify SWC-CH instead of SWC-BH? +
2. Is the SWC-CH torque rating different from SWC-BH for the same gyration diameter? +
3. How much axial travel does the SWC-CH telescoping shaft provide? +
4. Can I retrofit an SWC-CH in place of a worn SWC-BH on an existing installation? +
5. How quickly can I receive an SWC-CH from your Sydney warehouse? +
Request a Quote — Sydney NSW Stock
Tell us your motor power, shaft diameter, and operating environment. Our New South Wales coupling team confirms availability and pricing within one business day, with same-day dispatch on standard sizes from Condell Park.
Ever Power Flange Couplings Australia Ltd. · 27 Harley Crescent, Condell Park NSW 2200 · [email protected]
