The NGCLZ Drum Shape Gear Coupling with Brake Drum and Intermediate Shaft combines crowned-tooth torque transmission, an integral shoe-brake drum (D0 160–800 mm), and a shaft spacer in a single component per JB/T7003-93. Available in 14 sizes from 355 N·m to 100,000 N·m at up to 4000 RPM, with Y, J1, and Z1 taper bore options, it is engineered for mine hoists, cranes, and heavy-drive systems where motor and gearbox shaft ends are separated by a meaningful gap.
Three-in-one drive component: crowned-tooth gear coupling, integral shoe-brake drum, and intermediate shaft spacer — purpose-built for mine hoists, cranes, and heavy-drive systems with extended shaft separation.
The NGCLZ drum shape gear coupling with brake drum is the intermediate-shaft variant of the NGCL series — a three-function power transmission component that simultaneously transmits torque through two crowned gear meshes, provides an integral D0 cylindrical brake drum surface for a shoe brake assembly, and bridges the gap between motor and gearbox shaft ends through its intermediate shaft.
Where the NGCL is used when motor and gearbox shaft ends are closely adjacent, the NGCLZ is the engineering choice when those shaft ends are separated by a meaningful distance — a common layout in mine hoists, heavy cranes, and industrial drives where the gearbox is mounted away from the motor for structural or accessibility reasons.
The NGCLZ is a crowned-tooth gear coupling in the NGCL brake drum family, with the 'Z' suffix denoting the inclusion of an intermediate shaft (the connecting spacer tube between the two coupling halves).
This configuration produces two distinct gear meshes in series. Each mesh accommodates angular misalignment independently, so the NGCLZ's total angular compensation capacity is approximately twice that of a single-mesh coupling — making it more forgiving of shaft-to-shaft misalignment across a longer span.
The key differentiator from a straight-tooth gear coupling is the crowned (drum-shaped) tooth profile. A straight-tooth coupling transmits torque via a full-face line contact that concentrates stress at the tooth edge when angular misalignment is present — leading to accelerated wear and tooth breakage under the shock loading typical of hoist applications.
Unlike most gear couplings that offer a single bore type per half, the NGCLZ supports four factory-standard bore combination options. This flexibility allows a single NGCLZ size to serve a wide range of motor and gearbox shaft configurations without custom machining.
| Combination | Motor Side | Driven Side | Typical Use |
|---|---|---|---|
| Y / Y | Y cylindrical | Y cylindrical | Both shafts are standard cylindrical with keyway; most common general-purpose configuration |
| Y / J | Y cylindrical | J1 cylindrical (long) | Motor with standard Y shaft, gearbox or drum with longer J1 shaft; mixed motor/gearbox shaft standards |
| Z1 / J1 | Z1 conical taper (1:10) | J1 cylindrical | IEC motor with conical shaft end (Z1); preferred for high-cycle reversing or high-shock applications where keyless taper fit prevents fretting |
| J1 / J1 | J1 cylindrical (long) | J1 cylindrical (long) | Both shafts require long-engagement cylindrical bore; maximum bore engagement length on both sides |
| Feature | NGCLZ (this product) | Jaw Coupling | Disc Coupling | Rigid Flange |
|---|---|---|---|---|
| Integral Brake Drum | Yes — D0 shoe brake surface | No | No | No |
| Intermediate Shaft | Yes — standard feature | No | Spacer option available | No |
| Angular Misalignment | 1.0–1.5 deg per mesh (two meshes) | Up to 1 deg | Up to 1 deg | Near zero |
| Torque Range | 355 – 100000 KN·m | Low–Medium | Medium | High |
| Shock Load Tolerance | Excellent | Good (elastomer) | Poor | Transmitted fully |
| Axial Machine Withdrawal | Yes — remove spacer shaft | No | Spacer disc types only | No |
| Suitable for Hoisting / Crane | Yes — purpose-designed | No | No | No |
Both the NGCL and NGCLZ are drum shape gear couplings with integrated brake drums, share the same torque ratings, and conform to JB/T7003-93. The decision between them comes down to drivetrain geometry: NGCL for close-coupled shafts, NGCLZ when a shaft spacer is needed.
| Comparison Factor | NGCL (Close-Coupled) | NGCLZ (Intermediate Shaft) |
|---|---|---|
| Intermediate Shaft | No | Yes (standard) |
| Shaft-to-Shaft Gap | Short — shafts closely adjacent | Extended — shafts can be far apart |
| Gear Meshes | 1 pair | 2 pairs (higher misalignment) |
| Angular Misalignment | 1.0–1.5 deg (one mesh) | Up to 3 deg (two meshes combined) |
| Brake Drum (D0) | Integral on one half | Integral on one half |
| Machine Removal for Maintenance | Requires full coupling separation | Remove spacer shaft — motor or gearbox withdraws axially |
| Bore Combinations | Z1 or J1 / Y | Y/Y, Y/J, Z1/J1, J1/J1 |
| Overall Length | Shorter (B3) | Longer (B3 + intermediate shaft) |
| Choose When... | Shaft ends are closely spaced and B3 length fits the layout | Shaft ends are separated; maintenance withdrawal space is needed; higher misalignment is expected |
All specifications are from the NGCLZ catalogue per JB/T7003-93. Dimensions in millimetres. D0 is the brake drum outer diameter. B2 is the seal replacement clearance dimension. Bracketed D0 values indicate both drum diameters are available for that size.
| Type | Torque (KN·m) |
Speed (R/min) |
d1, d2 (mm) |
Y | J1, Z1 | D0 (brake) |
D | D1 | D2 | C | C1 | H | B | B1 | B2 | B3 | Inertia (Kg·m²) |
Weight (Kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NGCLZ1 | 355 | 4000 | 20, 22, 24 | 52 | 38 | 160 | 103 | 71 | 71 | 50 | 30 | 8 | 2 | 42 | 38 | 68 | 0.071 | 7.3 |
| 25, 28 | 62 | 44 | 0.072 | 7.4 | ||||||||||||||
| 30, 32, 35 | 82 | 60 | 0.076 | 8.4 | ||||||||||||||
| NGCLZ2 | 630 | 4000 | 25, 28 | 62 | 44 | 160 | 115 | 83 | 83 | 60 | 39 | 8 | 2 | 48 | 42 | 68 | 0.081 | 9.2 |
| 30, 32, 35, 38 | 82 | 60 | 0.084 | 10.3 | ||||||||||||||
| 40, 42, 45 | 112 | 84 | 0.088 | 10.5 | ||||||||||||||
| NGCLZ3 | 1000 | 3800 | 28 | 62 | 44 | 200 | 127 | 95 | 95 | 75 | 39 | 8 | 2 | 49 | 42 | 85 | 0.181 | 15.1 |
| 30, 32, 35, 38 | 82 | 60 | 0.184 | 16.3 | ||||||||||||||
| 40, 42, 45, 48, 50, 55 | 112 | 84 | 0.193 | 18.8 | ||||||||||||||
| NGCLZ4 | 1600 | 3800 | 38 | 82 | 60 | 200 | 149 | 116 | 116 | 90 | 46 | 8 | 2 | 53 | 42 | 85 | 0.225 | 19.8 |
| 40, 42, 45, 48, 50, 55, 56 | 112 | 84 | 0.242 | 23.3 | ||||||||||||||
| 60, 63, 65 | 142 | 107 | 0.296 | 26.8 | ||||||||||||||
| NGCLZ5 | 2800 | 3000 | 40–56 | 112 | 84 | 250 | 167 | 134 | 134 | 105 | 47 | 9 | 2.5 | 58 | 42 | 105 | 0.596 | 33.3 |
| 60–75 | 142 | 107 | 0.627 | 39 | ||||||||||||||
| NGCLZ6 | 4500 | 3000 | 45–56 | 112 | 84 | 250 | 187 | 153 | 153 | 125 | 52 | 9 | 2.5 | 59 | 42 | 105 | 0.72 | 40 |
| 60–75 | 142 | 107 | 0.776 | 46.4 | ||||||||||||||
| 80, 85, 90 | 172 | 132 | 0.837 | 53.2 | ||||||||||||||
| NGCLZ7 | 6300 | 2400 | 50, 55, 56 | 112 | 84 | 315 (300) | 204 | 170 | 170 | 140 | 52 | 9 | 2.5 | 63 | 42 | 132 | 1.178 | 51.8 |
| 60–75 | 142 | 107 | 1.254 | 59.8 | ||||||||||||||
| 80, 85, 90, 95 | 172 | 132 | 1.348 | 68.2 | ||||||||||||||
| 100 | 212 | 167 | 1.479 | 79.6 | ||||||||||||||
| NGCLZ8 | 9000 | 1900 | 55, 56 | 112 | 84 | 400 | 230 | 186 | 186 | 155 | 57 | 12 | 3 | 77 | 47 | 168 | 3.734 | 84 |
| 60–75 | 142 | 107 | 3.86 | 93.1 | ||||||||||||||
| 80, 85, 90, 95 | 172 | 132 | 3.996 | 104 | ||||||||||||||
| 100, 110 | 212 | 167 | 4.187 | 117 | ||||||||||||||
| NGCLZ9 | 14000 | 1500 | 60–75 | 142 | 107 | 500 | 256 | 212 | 212 | 180 | 64 | 13 | 3 | 47 | 47 | 210 | 9.43 | 133 |
| 80, 85, 90, 95 | 172 | 132 | 9.663 | 146 | ||||||||||||||
| 100, 110, 120, 125 | 212 | 167 | 9.997 | 164 | ||||||||||||||
| 130 | 252 | 202 | 10.3 | 182 |
| Type | Torque (KN·m) |
Speed (R/min) |
d1, d2 (mm) |
Y | J1, Z1 | D0 (brake) |
D | D1 | D2 | C | C1 | H | B | B1 | B2 (seal) |
B3 | Inertia (Kg·m²) |
Weight (Kg) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| NGCLZ10 | 20000 | 1200 | 65, 70, 71, 75 | 142 | 107 | 630 (600) | 287 | 239 | 200 | 120 | 65 | 15 | 3.5 | 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 | ||||||||||||||
| NGCLZ11 | 31500 | 1050 | 70, 71, 75 | 142 | 107 | 710 (700) | 325 | 276 | 235 | 134 | 77 | 16 | 3.5 | 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 | ||||||||||||||
| NGCLZ12 | 45000 | 1050 | 75 | 142 | 107 | 710 (700) | 362 | 313 | 270 | 164 | 94 | 17 | 4 | 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 | 325 | 282 | 53.69 | 464 | ||||||||||||||
| NGCLZ13 | 63000 | 950 | 150 | 252 | 202 | 800 | 412 | 350 | 300 | 165 | 88 | 18 | 4.5 | 113 | 49 | 335 | 82.7 | 490 |
| 160, 170, 180 | 302 | 242 | 84.7 | 544 | ||||||||||||||
| 190, 200, 220 | 352 | 282 | 86.67 | 596 | ||||||||||||||
| NGCLZ14 | 100000 | 950 | 170, 180 | 302 | 242 | 800 | 462 | 420 | 335 | 209 | 92 | 20 | 5.5 | 157 | 63 | 335 | 99.1 | 670 |
| 190, 200, 220 | 352 | 282 | 102.2 | 736 | ||||||||||||||
| 240, 250 | 410 | 330 | 105.9 | 785 |
Notes: B2 is the axial clearance dimension for seal replacement. Bracketed D0 values (e.g. 315/300, 630/600, 710/700) indicate both drum diameters are available for that size — verify with your shoe brake supplier before ordering.
Custom Bore, Intermediate Shaft Length & Brake Drum Size Available
Non-standard bore diameters, Z1 taper configurations, modified intermediate shaft lengths, and alternative D0 dimensions are all achievable to drawing. Contact our engineering team with your drivetrain drawing.
Mine hoists and crane hoist drives experience two types of severe loading simultaneously: torsional shock during load pickup, and combined torsional plus braking stress during emergency stops. The NGCLZ's crowned tooth profile distributes both loading types as Hertzian contact patches rather than concentrating them at tooth edges — significantly reducing peak tooth stress under both conditions.
A misaligned straight-tooth coupling transmits bending moments into both motor and gearbox bearings at 2× running frequency. In hoist applications, these forces add to the inherent radial loads from rope tension — compounding bearing fatigue. The NGCLZ's crowned tooth self-centres under load, generating substantially lower parasitic radial bearing forces.
Smaller NGCLZ sizes (NGCLZ1 through NGCLZ6) are rated to 3000–4000 RPM — appropriate for direct 4-pole motor coupling on 50 Hz supplies. The intermediate shaft is balanced as part of the complete coupling assembly.
NGCLZ couplings are manufactured from forged alloy steel blanks — 42CrMo4 for NGCLZ8 and above, 45# carbon steel for smaller sizes. The D0 brake drum surface and the crowned gear teeth are machined from the same forging, ensuring concentricity between the braking surface and the gear axis.
Crowned tooth profiles are generated on CNC gear hobbing machines with dedicated crowned tooling, achieving DIN Class 7 accuracy. The intermediate shaft is turned and bored to H7 tolerance on both end connections for accurate assembly.
The brake drum surface receives a dedicated finish-turning pass after heat treatment to achieve Ra 1.6–3.2 μm — the surface roughness specification required for consistent shoe brake operation and predictable brake shoe wear.
NGCLZ couplings are available from a single piece. Remote mine sites needing a single replacement NGCLZ on short notice are as welcome as OEM projects ordering a fleet of identical units. Standard catalogue sizes ship within 20–25 business days ex-works.
Custom intermediate shaft lengths, non-standard D0 diameters, modified B3 overall lengths, hardened and ground brake drum surfaces, and special bore combinations beyond the standard catalogue are all available.
RP is the manufacturer. No trading company mark-ups, no traceability chain gaps, no uncertainty about manufacturing origin.
Customer Profile: An underground gold producer operating a 2.8 MW friction winder at 980 m depth, with the drive motor and gearbox on opposite sides of the headframe crossbeam — a shaft gap of approximately 380 mm.
Challenge: The existing coupling arrangement used a close-coupled NGCL with a separate stub shaft adaptor to bridge the gap. The adaptor introduced eccentricity between the brake drum and gear axis, causing accelerated brake shoe wear and periodic shoe holder cracking from vibration.
Solution: We supplied a custom NGCLZ10 (20,000 N·m, 120 mm bore Z1/J1 combination, D0 = 630 mm) with a 380 mm intermediate shaft length matched exactly to the headframe geometry. A single integrated unit replaced the previous three-component assembly.
Result: Winder brake vibration reduced by 73% at the first post-installation measurement. No nuisance brake trips have been recorded in 22 months since installation. Brake shoe service life increased from approximately 8 months to over 18 months.
Customer Profile: A major iron ore port terminal operating two high-capacity shiploaders handling 90 Mt per annum combined throughput.
Challenge: The luffing drive on each shiploader used two motors driving a common gearbox through separate gear couplings, with each motor shaft end separated from the gearbox input by 450–500 mm due to the structural layout of the shiploader boom base.
Solution: We supplied 4× NGCLZ11 couplings (31,500 N·m, 150 mm bore, J1/J1 combination, D0 = 710 mm) per shiploader — two per motor shaft — with custom 450 mm intermediate shaft lengths. Full material traceability and inspection documentation supplied.
Result: Zero coupling failures in 26 months of continuous operation across all four units on both shiploaders. Port engineering management estimated that elimination of coupling-related outages represented a saving of over USD $400,000 in the first two years.
Customer Profile: An integrated steelworks operating 24 overhead cranes in the melt shop and casthouse, with hoist capacities from 50 to 320 tonnes.
Challenge: A fleet-wide coupling refurbishment identified that 18 of the 24 cranes used oversized close-coupled NGCL couplings fitted with custom adaptor shafts to bridge motor-to-gearbox gaps — an arrangement that introduced misalignment and had been causing premature coupling failures.
Solution: Working from the crane OEM's engineering drawings, we supplied 18 purpose-sized NGCLZ couplings (NGCLZ8 to NGCLZ12, torques 9,000–45,000 N·m) with intermediate shaft lengths matched to each crane's specific motor-to-gearbox gap.
Result: Fleet-wide hoist coupling failures reduced from 57 per year (pre-refurbishment) to 4 per year (minor seal replacements only) in the first 18 months post-installation — a 93% reduction. Total maintenance cost saving estimated at USD $280,000 per year.
The NGCLZ is a crowned-tooth gear coupling combining three functions: torque transmission through two crowned gear meshes, an integral D0 brake drum surface for a shoe brake assembly, and an intermediate shaft that bridges the motor-to-gearbox gap.
Both are brake drum gear couplings with the same D0 sizes and torque ratings. The NGCL is close-coupled (no spacer). The NGCLZ has an intermediate shaft that bridges a larger motor-to-gearbox gap, providing greater angular compensation capacity and the ability to match non-standard shaft separations.
Four standard combinations: Y/Y (both sides cylindrical Y type), Y/J (Y on one side, J1 long cylindrical on the other), Z1/J1 (1:10 conical taper on one side, J1 on the other), and J1/J1 (both sides J1 long cylindrical).
B2 is the axial clearance dimension for seal replacement. When a coupling seal reaches end-of-life and needs replacing during planned maintenance, B2 defines the axial space required to remove and fit the new seal without displacing the connected shafts.
Yes. The intermediate shaft length can be customised to your specific motor-to-gearbox gap dimension. Standard catalogue B3 lengths may not match your drivetrain geometry — particularly on older equipment or non-standard configurations. Provide your required gap dimension and we will verify the appropriate intermediate shaft length.
RP
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