GBC7Z Locking Assembly Rigid Coupling
The GBC7Z Locking Assembly Rigid Coupling is a keyless locking element coupling for shaft diameters from 15 mm to 110 mm. Using tapered inner and outer rings tightened by bolts to generate radial clamping pressure, it transmits higher torques than keyed or setscrew couplings and allows infinitely adjustable angular positioning between shaft and hub without keyways or shaft modification.
GBC7Z Locking Assembly Rigid Coupling — Keyless High-Torque Shaft-to-Hub Connection for Industrial Drives
The GBC7Z Locking Assembly Rigid Coupling is a precision keyless locking element designed to join long shafts and hubs where conventional keyed couplings or setscrew arrangements would be inadequate for the applied torque, or where adjustable angular positioning is required. By generating radial and friction forces through a tapered inner ring pressed against an outer taper surface under bolt tension, the GBC7Z achieves a secure, zero-backlash interference fit between shaft and hub without any keyways, setscrews, or shaft machining. The complete range covers shaft diameters from 15 mm to 110 mm, with outer diameters scaling from 45 mm to 160 mm and rated torques from 0.126 kN·m to 7.20 kN·m. Compare with other types in our rigid coupling catalogue or browse all coupling product families.
Working Principle
The GBC7Z locking assembly operates on a taper interference principle. The assembly consists of one inner ring and two tightening rings with conical taper surfaces, along with corresponding tightening bolts. When the bolts are tightened to the specified torque, the two tightening rings press inward along the taper faces, driving the inner ring radially inward against the shaft surface and radially outward against the hub bore simultaneously. The resulting radial pressure and friction force lock shaft and hub together without any modification to shaft or hub geometry. This design delivers simple structure, easy installation, straightforward bolt-release removal, and low cost per unit of transmitted torque.
Key Features
- Keyless interference fit — no keyways, slots, or shaft modification required
- Infinite angular adjustment between shaft and hub before bolt tightening
- High torque capacity up to 7.20 kN·m (GBC7Z110×160)
- Simple installation and removal using standard hex wrenches
- Compatible with shaft diameters 15 mm through 110 mm (31 standard sizes)
- Replaces keyed couplings in mechanical transmissions where shaft diameter and precision are the same
- Suited to both long shaft connections and shaft-to-hub drive assemblies
Dimensions & Technical Specifications
Full Specification Table — GBC7Z Series (All 31 Sizes)
| Model (d×D) | A (mm) | B (mm) | Bolts | Ft (kN) | Mt (kN·m) | Ps (MPa) | Ma (N·m) | G (kg) |
|---|---|---|---|---|---|---|---|---|
| GBC7Z15×45 | 50 | 56 | M6×4 | 16.8 | 0.126 | 127 | 17 | 0.4 |
| GBC7Z16×45 | 50 | 56 | M6×4 | 16.8 | 0.134 | 119 | 17 | 0.4 |
| GBC7Z17×45 | 50 | 56 | M6×4 | 16.8 | 0.142 | 112 | 17 | 0.4 |
| GBC7Z18×50 | 50 | 56 | M6×4 | 16.8 | 0.151 | 105 | 17 | 0.5 |
| GBC7Z19×50 | 50 | 56 | M6×4 | 16.8 | 0.159 | 100 | 17 | 0.5 |
| GBC7Z20×50 | 50 | 56 | M6×4 | 16.8 | 0.168 | 95 | 17 | 0.5 |
| GBC7Z22×55 | 60 | 66 | M6×4 | 25.2 | 0.277 | 103 | 17 | 0.7 |
| GBC7Z24×55 | 60 | 66 | M6×4 | 25.2 | 0.302 | 95 | 17 | 0.73 |
| GBC7Z25×55 | 60 | 66 | M6×6 | 25.2 | 0.315 | 91 | 17 | 0.77 |
| GBC7Z28×60 | 60 | 66 | M6×6 | 25.2 | 0.327 | 87 | 17 | 0.91 |
| GBC7Z30×60 | 60 | 66 | M6×6 | 25.2 | 0.352 | 81 | 17 | 0.81 |
| GBC7Z32×65 | 60 | 66 | M6×6 | 31.2 | 0.378 | 76 | 17 | 0.80 |
| GBC7Z35×75 | 75 | 83 | M8×4 | 31.2 | 0.499 | 80 | 42 | 1.30 |
| GBC7Z38×75 | 75 | 83 | M8×4 | 31.2 | 0.546 | 73 | 42 | 1.20 |
| GBC7Z40×75 | 75 | 83 | M8×4 | 31.2 | 0.592 | 67 | 42 | 1.40 |
| GBC7Z42×78 | 75 | 83 | M8×4 | 31.2 | 0.624 | 64 | 42 | 1.33 |
| GBC7Z45×85 | 85 | 93 | M8×6 | 46.8 | 0.982 | 74 | 42 | 2.30 |
| GBC7Z48×90 | 85 | 93 | M8×6 | 46.8 | 1.053 | 69 | 42 | 2.30 |
| GBC7Z50×90 | 85 | 93 | M8×6 | 46.8 | 1.123 | 65 | 42 | 2.50 |
| GBC7Z55×95 | 85 | 93 | M8×8 | 62.4 | 1.17 | 62 | 42 | 2.40 |
| GBC7Z60×100 | 85 | 93 | M8×8 | 62.4 | 1.17 | 58 | 42 | 3.00 |
| GBC7Z65×105 | 85 | 93 | M8×8 | 62.4 | 1.87 | 53 | 42 | 3.30 |
| GBC7Z70×115 | 100 | 110 | M10×6 | 62.4 | 2.02 | 49 | 84 | 4.10 |
| GBC7Z75×120 | 100 | 110 | M10×6 | 91 | 2.12 | 47 | 84 | 3.80 |
| GBC7Z80×125 | 100 | 110 | M10×8 | 98.4 | 3.44 | 66 | 84 | 5.20 |
| GBC7Z85×130 | 100 | 110 | M10×8 | 123 | 3.69 | 62 | 84 | 5.50 |
| GBC7Z90×135 | 100 | 110 | M10×8 | 123 | 4.92 | 73 | 84 | 7.00 |
| GBC7Z95×140S | 120 | 132 | M10×8 | 123 | 5.22 | 68 | 84 | 7.50 |
| GBC7Z100×150 | 120 | 132 | M12×8 | 144 | 5.53 | 65 | 145 | 7.80 |
| GBC7Z105×155 | 120 | 132 | M12×8 | 144 | 5.84 | 57 | 145 | 7.90 |
| GBC7Z110×160 | 120 | 132 | M12×8 | 180 | 7.20 | 65 | 145 | 10.4 |
Ft = Rated axial load (kN) | Mt = Rated torque (kN·m) | Ps = Surface pressure (MPa) | Ma = Tightening bolt torque (N·m) | G = Mass (kg)
How to Order — Part Number Guide
The GBC7Z part number follows this structure: GBC7Z[bore]×[outer diameter]
- bore = Shaft bore diameter in mm (15 through 110)
- outer diameter = Outer diameter of the coupling in mm (45 through 160)
- S suffix (e.g., GBC7Z95×140S) = special or modified configuration
Example: GBC7Z50×90 = Bore 50 mm, outer diameter 90 mm.
Industrial Applications
Gearbox & Reducer Hub Mounting
The GBC7Z replaces keyed hub-to-shaft connections on gearbox output flanges, eliminating key stress concentrations and allowing precise angular alignment of the driven component without keyway machining.
Conveyor & Material Handling Drives
Mining, port handling, and bulk material conveyor systems benefit from the high axial load rating and simple removal of GBC7Z assemblies during routine belt and sprocket replacement.
Wind Turbine & Renewable Energy
Large-bore GBC7Z assemblies (80×125 and above) are used in pitch and yaw drive transmissions on wind turbines, where keyless design simplifies maintenance in remote locations.
Paper & Printing Machinery
Roll-to-roll printing and paper converting machinery uses GBC7Z couplings to mount ink rollers and tension control shafts with consistent angular positioning across multiple removal-reinstallation cycles.
Our Manufacturing Facility
The GBC7Z locking assembly series is manufactured on precision CNC equipment with strict control over taper angles, surface finish, and thread quality. Each assembly is inspected for bolt torque consistency and taper surface concentricity before leaving our facility. Our production capabilities support both standard catalogue sizes and custom bore-to-OD combinations for specialised industrial equipment.
Customer Reviews & Case Studies
★★★★★
Australia — Mining Conveyor Systems
We adopted GBC7Z80×125 locking assemblies on our underground coal conveyor drive drums. Installation time per drum was reduced by over 60 percent compared to the previous keyed arrangement, and we have had zero instances of shaft key fretting in 24 months of operation. The removal process during planned maintenance shutdowns is also significantly more straightforward.
★★★★★
Germany — Industrial Gearbox OEM
We have standardised on the GBC7Z range for our helical gearbox output hub connections from 45 mm to 100 mm shaft sizes. The consistent taper quality and predictable bolt torque-to-clamping force relationship simplifies our assembly process. Dimensional tolerance has been excellent across multi-year supply volumes.
★★★★☆
India — Paper Mill Equipment
GBC7Z60×100 locking assemblies were fitted to our calender roll drive shafts. The ability to set precise angular positioning of the roll before tightening was a significant benefit compared to our previous keyed hubs. Overall performance and torque retention have been fully satisfactory.
★★★★★
Australia — Renewable Energy Infrastructure
We specified GBC7Z90×135 locking assemblies for pitch drive actuator hubs on a wind farm installation. The keyless design eliminated the risk of key fatigue failure under oscillating pitch loads, and the rated surface pressure of 73 MPa provided ample safety margin. Technical documentation was thorough and aided our maintenance planning.
Frequently Asked Questions
Does the GBC7Z require any special shaft or hub machining?
No special machining is required. The GBC7Z operates on standard cylindrical shaft and hub bore surfaces without keyways, grooves, or surface modifications. Recommended shaft tolerance is h6 or h7 and hub bore tolerance is H7, which are standard specifications available from most shaft suppliers.
What shaft diameter range does the GBC7Z Series cover?
The GBC7Z Series spans shaft bore diameters from 15 mm (GBC7Z15×45) to 110 mm (GBC7Z110×160), with 31 standard sizes covering the most common industrial shaft dimensions in that range.
How is the GBC7Z removed from a shaft after installation?
Removal is accomplished by progressively releasing the tightening bolts in a cross pattern, working in small increments per bolt to avoid cocking the taper rings. As tension is released, the taper rings relax and the shaft can be withdrawn. Under normal conditions, no shaft puller, hydraulic tools, or heating are required.
Can a GBC7Z replace a keyed coupling on an existing machine?
Yes. Where the hub bore and shaft diameter are compatible with a standard GBC7Z size and the GBC7Z rated torque meets or exceeds the application requirement, it can replace an existing keyed arrangement. The hub keyway can be left in place without affecting performance of the locking assembly.
What does the S suffix indicate on model GBC7Z95×140S?
The S suffix denotes a special or modified configuration at this particular bore-to-OD combination. This may indicate a modified outer diameter, adjusted bolt pattern, or application-specific surface treatment. Please contact us or consult the detailed drawing for full specification details.
Enquire About GBC7Z Locking Assembly Supply
The GBC7Z Series is available for B2B procurement in standard catalogue sizes and modified configurations. We supply OEM equipment builders, maintenance procurement teams, and authorised distributors across Australia and internationally. Technical drawing packages, material certificates, and volume pricing are available on request.
The GBC7Z Locking Assembly Rigid Coupling is a keyless locking element coupling for shaft diameters from 15 mm to 110 mm. Using tapered inner and outer rings tightened by bolts to generate radial clamping pressure, it transmits higher torques than keyed or setscrew couplings and allows infinitely adjustable angular positioning between shaft and hub without keyways or shaft modification.
