Wire Drum & Barrel Couplings
Wire drum (cable drum) and barrel couplings connecting the gearbox output shaft to the rope drum of cranes and hoists - selection by torque and radial load, replacement and interchange.
Wire Drum & Barrel Couplings
Engineering guide for crane and hoist drum drives - selection by torque and radial load, replacement and interchange. MECHATRIC helps crane OEMs, hoist engineers, maintenance teams and industrial buyers understand, specify, source and replace cable-drum couplings using a documented engineering workflow.
Manufacturer Reference Families - Not Automatic Equivalents
JAURE BARFLEX TCBR (TCB / TCB-HD)
Barrel couplings for crane drums, 21 sizes from 7,500 to 1,300,000 Nm, admissible radial loads up to 600 kN; successor to TCB / TCB-HD.
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WESTCAR ROTOGEAR AR-WB / AR-WG
All-steel cable-drum couplings: AR-WB barrel type, 20 sizes 6.5 to 1,050 kNm; AR-WG gear type, 16 sizes 13.5 to 835 kNm; ATEX on request.
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KCP Wire Drum Coupling
KCP (Korea Coupling) KWC wire drum couplings, 16 sizes from 4,510 to 685,000 Nm, radial loads up to 38,775 kg, bores up to 400 mm.
View Details →JAURE BARFLEX TCBR (TCB / TCB-HD)
Brand: JAURE (Regal Rexnord), Spain
JAURE TCB and TCB-HD barrel couplings were developed in the 1990s for hoisting applications; compared with gear couplings they accept higher misalignment with less bending stress and wear. The BARFLEX TCBR is the upgraded version and, according to JAURE, is 100% interchangeable with the TCB and TCB-HD ranges (within JAURE only). JAURE states that TCBR satisfies the German steel standard SEB 666212, Part 5 (1992).
- About 10% higher torque capacity than the previous design, allowing a more favourable size.
- Reduced assembly time; improved visual wear indicator; increased axial misalignment tolerance.
- Applications: cranes and hoisting (cable drum to gearbox output shaft), steel mills, winches, conveying, stackers and reclaimers.
- Variants: TCBR with splined shaft, TCBRA with limited axial travel, electronic wear indicator for hoisting.
- Selection per JAURE: check maximum permissible torque Tc MAX and admissible radial load Fr; if the calculated radial load exceeds Fr, a corrected radial load FA = Fr + (Tc MAX - T) / K1 may be checked before choosing a larger size; then verify the shaft connection.
BARFLEX TCBR Heavy Duty Standard Design
| Size | Selection standard SEB | Tc MAX (Nm) | Admissible radial load Fr (N) | Bore min - max (mm) | ØD (mm) | L (mm) |
|---|---|---|---|---|---|---|
| TCBR 25 | - | 7,500 | 19,600 | 38 - 68 | 250 | 95 |
| TCBR 50 | - | 9,500 | 22,250 | 48 - 80 | 280 | 100 |
| TCBR 75 | - | 12,000 | 24,000 | 58 - 90 | 320 | 110 |
| TCBR 100 | - | 16,300 | 29,700 | 58 - 100 | 340 | 125 |
| TCBR 130 | - | 23,500 | 41,800 | 78 - 115 | 360 | 130 |
| TCBR 160 | - | 29,100 | 46,000 | 78 - 130 | 380 | 145 |
| TCBR 200 | SG 130 | 33,900 | 50,850 | 98 - 136 | 400 | 170 |
| TCBR 300 | - | 42,600 | 58,250 | 98 - 156 | 420 | 175 |
| TCBR 400 | SG 140 | 57,200 | 82,500 | 98 - 185 | 450 | 185 |
| TCBR 500 | - | 102,600 | 133,400 | 98 - 215 | 510 | 220 |
| TCBR 600 | SG 185 | 138,150 | 143,650 | 118 - 235 | 550 | 240 |
| TCBR 1000 | SG 200 | 185,300 | 158,050 | 138 - 250 | 580 | 260 |
| TCBR 1500 | SG 240 | 250,700 | 190,750 | 158 - 295 | 650 | 315 |
| TCBR 2100 | - | 381,500 | 288,850 | 168 - 305 | 665 | 330 |
| TCBR 2600 | SG 270 | 442,800 | 334,800 | 168 - 315 | 680 | 350 |
| TCBR 3400 | SG 315 | 532,500 | 372,750 | 198 - 340 | 710 | 380 |
| TCBR 4200 | SG 355 | 665,650 | 426,000 | 228 - 385 | 780 | 410 |
| TCBR 6200 | SG 400 | 816,200 | 498,200 | 258 - 430 | 850 | 450 |
| TCBR 8200 | - | 900,000 | 525,000 | 255 - 455 | 940 | 500 |
| TCBR 9200 | - | 1,050,000 | 550,000 | 255 - 500 | 1025 | 500 |
| TCBR 10200 | - | 1,300,000 | 600,000 | 270 - 560 | 1120 | 500 |
Maximum bores for keyways to DIN 6885/1; other connections on request. Full dimensions per the JAURE drawing - available with the quotation. Source: JAURE BARFLEX TCBR Barrel Coupling catalogue. Technical modifications reserved by the manufacturer.
For a quotation send: crane / hoist duty and SEB group, power and drum speed, cable pull and drum weight, gearbox shaft and drum flange data, existing TCB / TCB-HD size if a replacement.
Information from the JAURE catalogue; brand names belong to their owners. MECHATRIC does not represent JAURE or Regal Rexnord and supplies original or equivalent couplings after dimensional and rating check.
Request a Quote for JAURE BARFLEX TCBR (TCB / TCB-HD) Ask an Engineer
WESTCAR ROTOGEAR AR-WB / AR-WG
Brand: WESTCAR s.r.l. (Milano, Italy)
ROTOGEAR AR couplings are all-steel couplings that connect the transmission to the cable drum in hoisting systems and other applications. According to WESTCAR they avoid the issues of rigid connections, eliminate the need for an additional (third) support, compensate angular misalignment and accept axial working positions of a few millimetres, proportional to coupling size. ATEX-certified versions can be supplied on request.
- AR...WB - barrel (roller) couplings for cable drums.
- AR...WG - gear-type couplings for cable drums.
- Selection per WESTCAR: size by shaft diameter (up to the maximum bore); torque MT max = P / n × fs × 955 (daNm) ≤ nominal torque; radial load P = T + G/2 (daN) ≤ permissible radial load. Service factors per DIN 15020 groups 1Bm-5m / FEM T1-T9: 1.12 to 3.
- Worked example (WESTCAR): 45 kW at 9 rpm, fs 2, 220 mm reducer shaft, cable pull 10,000 daN, drum 1,250 daN - MT = 9,550 daNm; suggested size AR 100WB.
AR...WB Barrel Couplings
| Size | Torque (kNm) | Radial load (kN) | Bore min - max (mm) | ØD (mm) | Axial offset (mm) | Weight (kg) |
|---|---|---|---|---|---|---|
| AR 2.5 WB | 6.5 | 17.5 | 38 - 68 | 250 | ±3 | 10 |
| AR 5 WB | 8 | 19.5 | 48 - 80 | 280 | ±3 | 13 |
| AR 7.5 WB | 9.4 | 21 | 58 - 90 | 320 | ±4 | 18 |
| AR 10 WB | 14.8 | 27 | 58 - 100 | 340 | ±4 | 23 |
| AR 13 WB | 20.8 | 37 | 78 - 115 | 360 | ±4 | 27 |
| AR 16 WB | 26 | 41 | 78 - 130 | 380 | ±4 | 32 |
| AR 20 WB | 30 | 45 | 98 - 136 | 400 | ±4 | 42 |
| AR 30 WB | 38 | 53 | 98 - 156 | 420 | ±4 | 49 |
| AR 40 WB | 52 | 74 | 98 - 185 | 450 | ±4 | 67 |
| AR 50 WB | 77 | 115 | 98 - 215 | 510 | ±6 | 101 |
| AR 60 WB | 120 | 130 | 118 - 235 | 550 | ±6 | 111 |
| AR 100 WB | 170 | 145 | 138 - 250 | 580 | ±6 | 149 |
| AR 150 WB | 230 | 175 | 158 - 295 | 650 | ±6 | 235 |
| AR 210 WB | 330 | 265 | 168 - 305 | 665 | ±6 | 261 |
| AR 260 WB | 410 | 31 * | 168 - 315 | 680 | ±6 | 288 |
| AR 340 WB | 500 | 350 | 198 - 340 | 710 | ±8 | 363 |
| AR 420 WB | 540 | 400 | 228 - 385 | 780 | ±8 | 483 |
| AR 620 WB | 770 | 470 | 258 - 430 | 850 | ±8 | 632 |
| AR 820 WB | 900 | 525 | 255 - 455 | 940 | ±10 | 806 |
| AR 920 WB | 1,050 | 550 | 255 - 500 | 1025 | ±10 | 944 |
* Value printed as 31 kN in the catalogue for size 260 - confirm with WESTCAR before selection.
AR...WG Gear Couplings for Cable Drums
| Size | Torque (kNm) | Radial load (kN) | Max. bore (mm) | Weight (kg) |
|---|---|---|---|---|
| AR WG 200 | 13.5 | 25 | 100 | 25 |
| AR WG 220 | 22 | 31 | 110 | 38 |
| AR WG 240 | 22 | 37 | 120 | 41 |
| AR WG 260 | 34 | 42 | 140 | 52 |
| AR WG 280 | 43 | 52 | 160 | 73 |
| AR WG 310 | 68 | 63 | 180 | 89 |
| AR WG 340 | 82 | 79.5 | 200 | 110 |
| AR WG 400 | 150 | 112.5 | 210 | 160 |
| AR WG 420 | 150 | 123 | 220 | 180 |
| AR WG 450 | 195 | 145 | 250 | 260 |
| AR WG 530 | 275 | 202 | 290 | 440 |
| AR WG 545 | 275 | 202 | 290 | 490 |
| AR WG 560 | 381 | 150 | 300 | 550 |
| AR WG 600 | 492 | 300 | 305 | 680 |
| AR WG 670 | 565 | 340 | 330 | 900 |
| AR WG 730 | 835 | 390 | 410 | 950 |
Full dimensions (flange, bolt circle, fixing holes, lengths) per the WESTCAR drawings - available with the quotation. Source: WESTCAR ROTOGEAR AR catalogue sheets 30-060 to 30-064 (05-2021).
For a quotation send: crane / hoist type and duty group, power and drum speed, cable pull and drum weight, reducer shaft diameter, drum flange data and the existing coupling size.
Information from the WESTCAR catalogue; brand names belong to their owners. MECHATRIC does not represent WESTCAR and supplies original or equivalent couplings after dimensional and rating check.
Request a Quote for WESTCAR ROTOGEAR AR-WB / AR-WG Ask an Engineer
KCP Wire Drum Coupling
Brand: KCP - Korea Coupling Co., Ltd. (South Korea)
The KCP Wire Drum Coupling (type KWC) is designed for the drum drive of cranes and conveying systems, including the rough operating conditions of iron and steel works and the continuous heavy-load operation of shore cranes. According to KCP, the circular (crowned) teeth carry high torque and high radial loads with much lower bending stress than typical gear teeth, preventing roller and bore breakage.
- Torque is transmitted through the two drag faces of the sleeve housed in the drum and through bolts fixed to the drum.
- Angular misalignment up to 1° via a crowned hub that oscillates in the sleeve.
- Axial displacement from ±3 mm up to ±8 mm depending on size; not suitable for absorbing or transmitting axial forces - the drum bearing bracket must be a fixed bracket.
- Selection per KCP: design torque = service factor × system torque (T = kW × 9,550 / rpm); cranes and hoists - main hoist 1.75, skip hoist 1.75, bridge / travel / trolley 1.75, slope 1.5. For brake applications use brake torque rating × service factor; for high peak or reversing loads use the KCP formula selection.
KWC Type - Ratings & Bores
| Size | Torque rating (Nm) | Radial load (kg) | Coupling weight (kg) | Max. bore (mm) | Min. bore (mm) |
|---|---|---|---|---|---|
| KWC 25 | 4,510 | 1,450 | 12 | 65 | 40 |
| KWC 50 | 5,980 | 1,680 | 19 | 75 | 50 |
| KWC 75 | 7,500 | 1,885 | 23 | 85 | 60 |
| KWC 100 | 9,015 | 2,040 | 27 | 95 | 60 |
| KWC 130 | 15,485 | 3,160 | 38 | 105 | 80 |
| KWC 160 | 19,500 | 3,570 | 48 | 120 | 80 |
| KWC 200 | 24,010 | 3,930 | 62 | 135 | 100 |
| KWC 300 | 27,980 | 4,285 | 76 | 145 | 100 |
| KWC 400 | 37,975 | 5,000 | 105 | 175 | 100 |
| KWC 600 | 69,970 | 11,735 | 190 | 205 | 120 |
| KWC 1000 | 120,000 | 12,755 | 240 | 230 | 140 |
| KWC 1500 | 180,000 | 15,305 | 400 | 280 | 160 |
| KWC 2600 | 310,000 | 25,510 | 500 | 300 | 170 |
| KWC 3400 | 400,000 | 31,295 | 630 | 315 | 200 |
| KWC 4200 | 500,000 | 34,695 | 840 | 355 | 230 |
| KWC 6200 | 685,000 | 38,775 | 1,120 | 400 | 260 |
Coupling weight without bore machining. Full dimensions (drum diameter, flange, fixing holes, clearances) per the KCP KWC drawing - available with the quotation. Source: KCP Wire Drum Coupling catalogue (Ver. 2017-04). Verify torque and radial load for the actual crane geometry before selection.
For a quotation send: crane / hoist type and duty, power and drum speed, rope pull and drum weight, gearbox shaft diameter, drum flange data and the existing coupling size.
Information from the KCP catalogue; brand names belong to their owners. MECHATRIC does not represent KCP and supplies original or equivalent couplings after dimensional and rating check.
What is a wire drum coupling?
A wire drum coupling (also called a cable drum coupling, hoist drum coupling or, for the roller-element design, a barrel coupling) connects the gearbox output shaft to the rope or cable drum in a crane or lifting mechanism. Unlike an ordinary shaft-to-shaft coupling, the drum-side unit can form part of the drum support arrangement and must be evaluated for both transmitted torque and radial load. The term "wire drum coupling" describes an application, not a single interchangeable construction.
Why use a drum coupling instead of a rigid connection?
A rigidly coupled gearbox / drum with additional supports can introduce an over-constrained arrangement. Misalignment, structural deflection and wear may produce unwanted bending forces at the gearbox shaft and bearings. The articulated barrel coupling arrangement can accommodate permitted angular / axial movements and reduce these imposed bending effects when the drum support system is designed correctly. The opposite drum bearing must still provide the axial restraint required by the system unless an approved axial-force-bearing coupling variant is specified.
How does a barrel coupling work?
In the JAURE TCB design, hardened cylindrical barrels run between complementary semicircular profiles on the hub and sleeve. The barrel contacts transmit torque and distribute substantial radial reaction forces while permitting limited articulation. Sealed covers retain grease and protect the internal elements. Manufacturer-provided wear and axial-position indicators can support maintenance checks. The precise internal geometry, load rating, lubrication and wear criteria are series-specific.
Main Types and Configurations
| Configuration | Engineering interpretation / use |
|---|---|
| Barrel / roller drum coupling | Roller / barrel contact elements; commonly selected for high radial load and articulated gearbox-to-drum connections. |
| Gear-type drum coupling | Gear-tooth contact arrangement; requires its own torque, radial-load, misalignment and lubrication validation. |
| Heavy-duty barrel coupling | Higher-duty series with its own allowable torque, radial force and shaft-bore envelope. |
| Special flange / splined connection | Custom drum attachment or shaft interface; dimensions and fit must be checked against drawings. |
| Axial-load-capable design | Special design for systems requiring the coupling itself to react axial forces; not assumed for standard units. |
Engineering Selection: Torque AND Radial Load
| Step | Engineering input / decision |
|---|---|
| 1. Gather duty | Hoist capacity, drum diameter, rope arrangement, reeving ratio, drum mass, cable load, operating classification, starts / hour, reversals, emergency stops, braking arrangement, speed and ambient conditions. |
| 2. Transmission torque | T (Nm) = 9550 × P (kW) / n (rpm); apply the manufacturer operating / service factor and maximum load cases. WESTCAR uses the equivalent MT = 955 × P × fs / n in daNm - do not mix daNm, Nm or kNm. |
| 3. Radial reaction | Coupling-side radial load from rope pull, drum weight, reeving, drum bearing span and cable position. WESTCAR gives a simplified case P = T + G/2 (daN); JAURE gives geometry- and reeving-dependent load cases - not universally interchangeable formulas. |
| 4. Verify both ratings | Catalogue nominal torque must exceed design torque, and permissible radial load must exceed the calculated coupling reaction for the applicable geometry and duty. Confirm the supplier's combined-load rules. |
| 5. Geometry and fit | Gearbox shaft diameter, hub bore limits, keyway / spline / shrink fit, flange PCD, pilot, bolt arrangement, axial assembly space, drum interface, allowable misalignment and axial displacement. |
| 6. Safety and maintenance | Lubrication type and interval, seal system, wear indicator, mounting / bolt torque, inspection access, applicable crane duty standard and required documentation. |
Illustrative selection - why a torque-only check is insufficient
45 kW at 9 rpm with a service factor of 2: design torque = 9550 × 45 / 9 × 2 = 95,500 Nm (95.5 kNm = 9,550 daNm). WESTCAR's published example uses a 220 mm reducer shaft and identifies an AR 100WB candidate. The actual drum radial reaction and dimensional fit must also be verified; this illustration is not a general product recommendation.
Radial-Load and Structural Considerations
- Treat the coupling as one of the drum supports where the selected design and assembly permit it; verify the drum-side support and bearing arrangement.
- Calculate maximum static and dynamic cable pull with reeving efficiency, lifting acceleration, shock, emergency braking and load eccentricity where applicable.
- Check overhung cable location and the drum span; rope loading changes along the drum as the cable winds.
- Check radial-force limits against supplier data; do not extrapolate permissible load from nominal torque alone.
- Confirm the axial load path - standard barrel couplings may permit axial movement without providing axial restraint.
Misalignment, Installation and Lubrication
Manufacturer limits are not universal. The JAURE TCB catalogue describes angular movement up to ±1°30′ and axial travel varying by size (approx. ±3 to ±8 mm); these values are JAURE-specific and must not be applied to WESTCAR or KCP without verification. WESTCAR likewise describes compensation of angular and axial misalignment for its ROTOGEAR range, subject to size and installation instructions.
- Confirm mounting surfaces, shaft / hub fits, flange concentricity, fastener grade and specified tightening sequence.
- Align the gearbox / drum assembly to the supplier's cold-installation reference position; account for expected structural deflection.
- Use the manufacturer-approved grease and relubrication procedure; inspect seals for leakage or contamination.
- Monitor wear indicators and axial-position references where fitted; replace or repair at the manufacturer's defined limit.
- Never assume a drum coupling is maintenance-free or that the same grease interval applies across brands.
Barrel Coupling vs Gear Drum Coupling
| Factor | Barrel / roller design | Gear drum design |
|---|---|---|
| Torque transfer | Hardened barrels between shaped contact profiles | Meshing gear-tooth profiles |
| Radial reaction | Catalogue-dependent; often designed specifically for high radial reactions | Catalogue-dependent; evaluate tooth / contact and radial reaction |
| Misalignment | Articulation and axial travel within model limits | Model-specific angular / axial allowances |
| Replacement | Requires both torque and radial-load verification | Requires both torque and radial-load verification |
Replacement & Interchange Engineering Workflow
A drum coupling replacement is a structural load-path assessment, not merely a dimensional match. Start from the installed manufacturer, series and size; obtain nameplate, drawings and photographs; reconstruct operating loads; then compare candidate designs against the full requirement envelope.
| Comparison field | Required validation |
|---|---|
| Duty | Hoist class, power, rpm, torque, overload, reversals, brake / emergency duty |
| Radial loading | Rope pull, drum mass, load position, bearing span, permissible radial load |
| Shaft / hub | Bore, keyway / spline, tolerances, shaft engagement, hub length |
| Drum flange | Bolt circle, pilot, drive faces / pins, flange thickness and axial space |
| Motion / support | Angular and axial allowance; axial thrust path; support bearing concept |
| Reliability | Lubrication, sealing, wear monitoring, materials, corrosion and service access |
| Compliance | Applicable crane / hoist design rules, OEM approvals and inspection documentation |
MECHATRIC interchange classification: Direct Interchange | Dimensionally Compatible | Functionally Equivalent | Engineering Review Required. An advertised "same size" or manufacturer-internal interchange claim is insufficient to establish equivalence between different brands.
Typical Applications and Industries
- Overhead travelling cranes, gantry cranes, steel-mill cranes and foundry lifting systems.
- Electric wire-rope hoists, winches, platform hoists, port and bulk-material handling.
- Mining, cement, steel, marine, heavy fabrication and industrial material handling.
- Drum drive upgrades, gearbox replacements, crane modernisation and maintenance projects.
Data Required for a Technical RFQ
Application / crane type; OEM and duty class; maximum lifted load; drum pitch diameter and width; reeving arrangement and number of falls; cable pull; drum weight and support span; power (kW); drum speed (rpm); service factor or duty cycle; starts / hour; emergency brake torque; gearbox shaft diameter and fit; drum flange dimensions / PCD; installation drawing; required angular and axial allowance; lubrication and environment; existing brand / size; replacement deadline; standards and certification needs.
Leading Manufacturers Worldwide
Well-known European, American and Asian (Japanese and Korean) manufacturers of wire drum & barrel couplings.
| Manufacturer | Country | Product focus |
|---|---|---|
| JAURE (Regal Rexnord) | Spain | Barrel (drum) couplings, gear and disc couplings |
| MALMEDIE | Germany | Drum couplings, gear couplings, brakes for cranes |
| Westcar | Italy | Fluid and gear couplings, drum and disc brakes |
| KCP (Korea Coupling) | South Korea | Grid and gear couplings |
Listed for market information only. Brand names belong to their owners; their mention does not imply that MECHATRIC represents, distributes for or is authorized by these manufacturers. Product availability and equivalents are confirmed per enquiry.
Need a drum coupling or a replacement?
Submit the existing coupling drawings, crane data and loads - MECHATRIC checks torque, radial load and interfaces and prepares the RFQ.
Sources: KCP Wire Drum Coupling catalogue; WESTCAR ROTOGEAR AR-WB / AR-WG (05-2021); JAURE TCB / TCB-HD Barrel Coupling catalogue. Manufacturer names and series are reference examples only; no agency, authorisation, stock availability, direct interchange or compliance certification is implied. Ratings and service factors are manufacturer- and revision-specific; final selection, lifting safety and structural verification require current original manufacturer documents and approval by a qualified engineer.
Frequently Asked Questions
Is a wire drum coupling the same as a barrel coupling?
Not always. "Wire / cable drum coupling" names the application. A barrel coupling is one common construction; gear-type drum couplings also exist.
Can I select from motor power and rpm alone?
No. The coupling's radial support reaction, rope / reeving geometry and interface dimensions are equally critical.
Can a barrel coupling replace a gear drum coupling?
Possibly, after a complete engineering check of torque, radial load, drum / shaft interfaces, space, movement and maintenance needs.
Does a drum coupling remove the need for a drum bearing?
No. It can eliminate an additional support in some configurations, but the remaining drum support and axial load path must be correctly engineered.
Are all TCB, AR-WB and KCP sizes interchangeable?
No. Brand-specific size numbers and tables are not a universal interchange standard.