The NGCL Drum Shape Gear Coupling with Brake Drum integrates a cylindrical brake drum for shoe brakes per JB/T7003-93, covering 14 sizes from 355 N·m to 100,000 N·m at up to 4000 RPM. With brake drum diameter D0 from 160–800 mm and Y, J1, Z1 bore options, it is the preferred solution for crane hoists, mine winders, and heavy-drive systems where combined torque transmission and braking capability are required in a single compact component.
Crowned-tooth gear coupling with integrated brake drum for shoe brakes — engineered for hoisting, crane, and heavy-drive applications requiring simultaneous power transmission and braking.
The NGCL drum shape gear coupling is a dual-function power transmission component: it simultaneously acts as a crowned-tooth gear coupling connecting two shafts and provides an integral cylindrical brake drum surface (D0) for a mating shoe brake assembly. One component handles both jobs — eliminating the separate brake drum, shaft adaptor, and additional bearing that a discrete brake drum arrangement would require.
The coupling conforms to JB/T7003-93 and covers 14 sizes from NGCL1 to NGCL14, spanning a torque range from 355 N·m to 100,000 N·m. The brake drum diameter D0 — the critical dimension for shoe brake selection — ranges from 160 mm (NGCL1) to 800 mm (NGCL14).
Among drum shape gear couplings, the NGCL is unique in integrating a brake drum directly into the coupling body. One coupling half (typically the motor side, accepting the Z1 taper bore) is machined with the D0 cylindrical surface on its outer diameter — this is the braking surface against which the shoe brake pads clamp.
This integrated design eliminates the need for a separate brake drum component elsewhere on the shaft. It reduces overall drivetrain length, removes the alignment requirement between a separate brake drum and the coupling axis, and eliminates one shaft journal from the motor or gearbox.
The gear coupling function of the NGCL uses crowned (drum-shaped) tooth geometry on both external gear hubs. This is the key differentiator from a straight-tooth gear coupling: the crowned profile maintains near-central Hertzian tooth contact regardless of shaft angular offset, preventing the edge-loading that causes premature tooth failure in misaligned straight-tooth couplings.
The D0 dimension is the outer diameter of the integral brake drum surface machined on the larger coupling half. When a shoe brake is specified to work with an NGCL coupling, the brake is sized using D0 as the reference diameter — brake torque capacity scales with D0 and braking force.
The structural integrity of the integrated drum is designed to handle the combined loading of simultaneous torque transmission through the gear mesh and radial clamping force from the shoe brake pads.
The NGCL gear mesh accommodates angular misalignment of 1.0 to 1.5 degrees, radial parallel offset, and axial displacement. The axial sliding capability is particularly important in hoisting applications where thermal expansion of the drive shaft occurs during extended operation.
| Feature | NGCL Drum Gear + Brake | Gear Coupling (No Brake) | Jaw Coupling | Disc Coupling |
|---|---|---|---|---|
| Integrated Brake Drum | Yes — D0 surface for shoe brake | No — separate drum required | No | No |
| Torque Capacity (this range) | 355 – 100000 KN·m | High | Low–Medium | Medium |
| Angular Misalignment | 1.0 – 1.5 deg per mesh | 1.0 – 1.5 deg | Up to 1 deg | Up to 1 deg |
| Shock Load Tolerance | Excellent | Excellent | Good | Poor |
| Drive Train Length | Compact — drum integral | Requires separate brake drum | Compact | Compact |
| Suitable for Hoisting/Crane Use | Yes — purpose-designed | Only with separate brake | No | No |
| Z1 Taper Bore Support | Yes | Depends on type | Limited | No |
All specifications below are from the NGCL product catalogue per JB/T7003-93. All dimensions in millimetres. D0 is the brake drum outer diameter — the critical dimension for shoe brake selection. The dz column shows the Z1 taper bore range (conical motor shaft connection).
| Type | Torque (KN·m) |
Speed (R/min) |
dz range (mm) |
d1, d2 (mm) |
Y | J1, Z1 | D0 (brake drum) |
D | D1 | D2 | C | C1 | H | B | B1 | B2 | B3 | Inertia (Kg·m²) |
Weight (Kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NGCL1 | 355 | 4000 | 20 – 35 | 20, 22, 24 | 52 | 38 | 160 | 103 | 71 | 50 | 30 | 8 | 2 | 56 | 42 | 38 | 68 | 0.07 | 7 |
| 25, 28 | 62 | 44 | 0.07 | 7.3 | |||||||||||||||
| 30, 32, 35 | 82 | 60 | 0.071 | 8 | |||||||||||||||
| NGCL2 | 630 | 4000 | 25 – 45 | 25, 28 | 62 | 44 | 160 | 115 | 83 | 60 | 36 | 8 | 2 | 68 | 48 | 42 | 68 | 0.079 | 9 |
| 30, 32, 35, 38 | 82 | 60 | 0.08 | 9.7 | |||||||||||||||
| 40, 42, 45 | 112 | 84 | 0.083 | 11 | |||||||||||||||
| NGCL3 | 1000 | 3800 | 30 – 55 | 28 | 62 | 44 | 200 | 127 | 95 | 75 | 41 | 8 | 2 | 70 | 49 | 42 | 85 | 0.181 | 14.6 |
| 30, 32, 35, 38 | 82 | 60 | 0.184 | 15.2 | |||||||||||||||
| 40, 42, 45, 48, 50, 55, 56 | 112 | 84 | 0.187 | 17 | |||||||||||||||
| NGCL4 | 1600 | 3800 | 40 – 65 | 38 | 82 | 60 | 200 | 149 | 116 | 90 | 41 | 8 | 2 | 74 | 53 | 42 | 85 | 0.225 | 18.6 |
| 40, 42, 45, 48, 50, 55, 56 | 112 | 84 | 0.237 | 21.4 | |||||||||||||||
| 60, 63, 65 | 142 | 107 | 0.246 | 23.8 | |||||||||||||||
| NGCL5 | 2800 | 3000 | 45 – 75 | 40–56 | 112 | 84 | 250 | 167 | 134 | 105 | 48 | 8 | 2.5 | 84 | 58 | 42 | 105 | 0.58 | 31.8 |
| 60, 63, 65, 70, 71, 75 | 142 | 107 | 0.609 | 34.4 | |||||||||||||||
| NGCL6 | 4500 | 3000 | 50 – 90 | 45, 48, 50, 55, 56 | 112 | 84 | 250 | 187 | 153 | 125 | 49 | 9 | 2.5 | 85 | 59 | 42 | 105 | 0.714 | 37.2 |
| 60, 63, 65, 70, 71, 75 | 142 | 107 | 0.754 | 38.5 | |||||||||||||||
| 80, 85, 90 | 172 | 132 | 0.795 | 47.6 | |||||||||||||||
| NGCL7 | 6300 | 2400 | 60 – 100 | 50, 55, 56 | 112 | 84 | 315 (300) | 204 | 170 | 140 | 53 | 9 | 2.5 | 93 | 63 | 42 | 132 | 1.17 | 48.8 |
| 60, 63, 65, 70, 71, 75 | 142 | 107 | 1.234 | 55.2 | |||||||||||||||
| 80, 85, 90, 95 | 172 | 132 | 1.299 | 61.8 | |||||||||||||||
| 100 | 212 | 167 | 1.388 | 71.1 |
| Type | Torque (KN·m) |
Speed (R/min) |
dz range (mm) |
d1, d2 (mm) |
Y | J1, Z1 | D0 (brake drum) |
D | D1 | D2 | C | C1 | H | B | B1 | B2 | B3 | Inertia (Kg·m²) |
Weight (Kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NGCL8 | 9000 | 1900 | 70 – 110 | 55, 56 | 112 | 84 | 400 | 230 | 186 | 155 | 64 | 12 | 3 | 112 | 77 | 47 | 168 | 3.747 | 80.7 |
| 60, 63, 65, 70, 71, 75 | 142 | 107 | 3.841 | 90 | |||||||||||||||
| 80, 85, 90, 95 | 172 | 132 | 3.939 | 96.5 | |||||||||||||||
| 100, 110 | 212 | 167 | 4.072 | 108 | |||||||||||||||
| NGCL9 | 14000 | 1500 | 80 – 130 | 60, 63, 65, 70, 71, 75 | 142 | 107 | 500 | 256 | 212 | 180 | 71 | 13 | 3 | 119 | 80 | 47 | 210 | 9.427 | 128 |
| 80, 85, 90, 95 | 172 | 132 | 9.605 | 138 | |||||||||||||||
| 100, 110, 120, 125 | 212 | 167 | 9.847 | 151 | |||||||||||||||
| 130 | 252 | 202 | 10.109 | 167 | |||||||||||||||
| NGCL10 | 20000 | 1200 | 80 – 150 | 65, 70, 71, 75 | 142 | 107 | 630 (600) | 287 | 239 | 200 | 65 | 15 | 3.5 | 120 | 90 | 47 | 265 | 28.238 | 176 |
| 80, 85, 90, 95 | 172 | 132 | 28.509 | 190 | |||||||||||||||
| 100, 110, 120, 125 | 212 | 167 | 28.879 | 209 | |||||||||||||||
| 130, 140, 150 | 252 | 202 | 29.248 | 237 | |||||||||||||||
| NGCL11 | 31500 | 1050 | 100 – 170 | 70, 71, 75 | 142 | 107 | 710 (700) | 325 | 276 | 235 | 77 | 16 | 3.5 | 134 | 94 | 47 | 298 | 44.309 | 257 |
| 80, 85, 90, 95 | 172 | 132 | 44.825 | 275 | |||||||||||||||
| 100, 110, 120, 125 | 212 | 167 | 45.53 | 300 | |||||||||||||||
| 130, 140, 150 | 252 | 202 | 46.235 | 326 | |||||||||||||||
| 160, 170 | 302 | 242 | 47.08 | 357 | |||||||||||||||
| NGCL12 | 45000 | 1050 | 100 – 200 | 75 | 142 | 107 | 710 (700) | 362 | 313 | 270 | 94 | 17 | 4 | 164 | 104 | 49 | 298 | 47.88 | 306 |
| 80, 85, 90, 95 | 172 | 132 | 48.29 | 317 | |||||||||||||||
| 100, 110, 120, 125 | 212 | 167 | 49.52 | 351 | |||||||||||||||
| 130, 140, 150 | 252 | 202 | 50.25 | 384 | |||||||||||||||
| 160, 170, 180 | 302 | 242 | 52.22 | 425 | |||||||||||||||
| 190, 200 | 352 | 282 | 53.69 | 464 | |||||||||||||||
| NGCL13 | 63000 | 950 | 150 – 220 | 150 | 252 | 202 | 800 | 412 | 350 | 300 | 88 | 18 | 4.5 | 165 | 113 | 49 | 335 | 82.7 | 490 |
| 160, 170, 180 | 302 | 242 | 84.7 | 544 | |||||||||||||||
| 190, 200, 220 | 352 | 282 | 86.67 | 596 | |||||||||||||||
| NGCL14 | 100000 | 950 | 170 – 220 | 170, 180 | 302 | 242 | 800 | 462 | 420 | 335 | 92 | 20 | 5.5 | 209 | 157 | 63 | 335 | 99.1 | 670 |
| 190, 200, 220 | 352 | 282 | 102.2 | 736 | |||||||||||||||
| 240, 250 | 410 | 330 | 105.9 | 785 |
Note: D0 values in parentheses (e.g. 315/300, 630/600, 710/700) indicate that both drum diameters are available for the same coupling size. verify D0 with your shoe brake supplier before ordering. Shaft hole lengths follow J1 type recommendation.
Custom Bore & Brake Drum Specifications Available
Need a non-standard bore, Z1 taper ratio, or a specific brake drum surface finish? Our engineering team accommodates custom specifications including alternative D0 diameters, hardened drum surfaces, and non-standard keyway profiles. Contact us with your requirements.
Crane hoist drives experience peak torque spikes when a load is lifted from rest or when the hoist engages after a slack rope condition. These instantaneous torque spikes can reach 3–5× the nominal drive torque. The NGCL's crowned tooth profile distributes these peaks as a Hertzian contact patch rather than concentrating them at tooth edges — significantly reducing the risk of tooth breakage under shock loading.
A misaligned straight-tooth gear coupling generates bending moments that impose cyclic radial forces at 2× running frequency on motor and gearbox bearings. In hoist applications, these forces combine with the inherent radial loads from rope tension — accelerating bearing fatigue. The NGCL's crowned tooth self-centres under load, generating lower parasitic radial forces.
Lubrication intervals for NGCL couplings are typically 6–12 months under normal operating conditions. In mine hoist applications where the coupling is located in a headframe above the shaft collar, access can be challenging — confirming that the NGCL's less frequent maintenance requirement is a practical operational advantage.
Large hoist motors and gearboxes experience significant thermal expansion during continuous operation — a 4-pole 1.5 MW motor shaft can extend axially by 0.5–1.5 mm between cold start and steady-state temperature. The NGCL's axial compliance absorbs this growth without transmitting axial loads to motor or gearbox bearings.
Every NGCL coupling begins as a forged alloy steel blank — 42CrMo4 for NGCL8 and above, 45# carbon steel for smaller sizes. The brake drum surface (D0) and gear teeth are machined from the same forging — ensuring concentricity between the braking surface and gear axis.
The crowned tooth profiles are generated on CNC gear hobbing machines with dedicated crowned-tooth tooling, achieving DIN Class 7 accuracy or better. Tooth flanks are carburised and quenched to achieve 58–62 HRC surface hardness, with the brake drum surface finish-turned after heat treatment.
Our quality laboratory operates CNC gear profile testers for crowned tooth geometry verification, Rockwell hardness testers for post-quench surface hardness confirmation, and coordinate measuring machines (CMM) for dimensional inspection.
ISO 9001:2015 certification covers the complete NGCL manufacturing process. Products are manufactured to JB/T7003-93.
NGCL couplings are available from single-piece orders — important for maintenance replacement scenarios where a mine site needs an exact replacement without committing to a large stockholding. Volume pricing applies for orders of 5 or more units of the same size.
Beyond standard JB/T7003-93 dimensions, we manufacture to customer drawings. Non-standard D0 diameters, modified B3 overall lengths, hardened and ground brake drum surfaces, and special bore configurations are all achievable.
RP manufactures every NGCL in our own facility. No intermediaries, no grey-market stock, no traceability gaps.
Customer Profile: A mid-tier underground gold producer operating a 3.2 MW drum hoist for skip winding at 1,100 metres depth.
Challenge: The existing brake drum gear coupling was exhibiting tooth spalling after 14 months in service. Vibration analysis confirmed 2×-frequency excitation consistent with misalignment-induced edge loading on a straight-tooth gear coupling.
Solution: We supplied an NGCL11 coupling (31,500 N·m rated torque, 130 mm bore, Z1 taper bore on the motor side, D0 = 710 mm) with a hardened and ground brake drum surface finish to Ra 1.6 for improved shoe brake performance.
Result: After 28 months in continuous service, the replacement coupling shows no tooth wear indicators on vibration monitoring. Brake shoe wear rate reduced by approximately 30% due to the improved drum surface finish.
Customer Profile: A major aluminium smelter operating 8 ladle cranes in the casthouse, each lifting molten metal ladles up to 120 tonnes.
Challenge: The hoist drum drive couplings were being replaced every 10–12 months due to accelerated tooth wear. Investigation revealed that the high ambient casthouse temperatures were degrading the standard grease before the scheduled re-lubrication interval.
Solution: We supplied 8× NGCL9 couplings (14,000 N·m, 110 mm bore, D0 = 500 mm) with a high-temperature lithium complex grease filling rated for continuous operation to 180°C. The crowned tooth profile maintained adequate contact geometry even with partially degraded lubrication.
Result: After 24 months, no coupling replacements have been required on any of the 8 cranes. The maintenance team confirmed that tooth wear at 24 months was within acceptable limits per the manufacturer's wear criteria.
Customer Profile: A coal export terminal operating two coal shiploaders handling 30 million tonnes per annum.
Challenge: The shiploader luffing drive couplings were failing due to high cyclic load reversals from wind-induced boom movement. Each torque reversal was causing micro-slip at the straight-tooth coupling interface, leading to fretting wear and eventual tooth failure.
Solution: We supplied 4× NGCL10 couplings (20,000 N·m, 140 mm bore, D0 = 630 mm) per shiploader — replacing the existing coupling plus separate brake drum with a single integrated NGCL unit.
Result: Brake shoe service life increased by approximately 65% following installation, eliminating two unplanned brake inspections per shiploader per year. The couplings have operated for 30 months without replacement.
The NGCL is a crowned-tooth gear coupling with an integrated brake drum machined into one coupling half. It transmits torque between two shafts while providing a D0 cylindrical surface for a shoe brake assembly — combining two drive components into one.
D0 is the outer diameter of the cylindrical braking surface machined into one coupling half. A shoe brake assembly clamps its brake blocks against this surface to decelerate or hold the drivetrain. When ordering, verify D0 matches your shoe brake's working diameter.
The NGCL accepts Z1 (1:10 conical taper bore, on the dz side — typically motor side), J1 (cylindrical shaft with keyway, longer engagement), and Y (cylindrical with keyway, standard length). The dz range in the specification table shows the Z1 taper bore diameter range available for each size.
The NGCL is a close-coupled variant where both coupling halves connect directly to adjacent shaft ends. The NGCLZ adds an intermediate shaft between the two halves, allowing the coupling to bridge a gap between motor and gearbox shaft ends that are separated by a significant distance.
Yes. We supply custom Z1 taper bores, non-standard cylindrical bore diameters, special keyway profiles, and alternative D0 brake drum diameters to customer drawings. For non-standard D0, we assess the structural implications and verify feasibility before committing to manufacture.
RP
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