GL series disc coupling with an anodised aluminium alloy body and 304 stainless steel diaphragms, clamped onto the shaft with screw clamp hubs rather than set screws. The clamp hub grips the full shaft circumference, so there is no fretting and no marking of the shaft, and the coupling can be removed and refitted many times. Zero backlash and high torsional rigidity for servo and stepper positioning axes. Outer diameters 19 to 82 mm, bores 4 to 42 mm.
Technical specifications
| Series | GL |
|---|---|
| Coupling type | Disc (diaphragm) coupling, zero backlash |
| Body material | Aluminium alloy |
| Diaphragm material | 304 stainless steel |
| Surface treatment | Anodised |
| Shaft attachment | Clamp type hub (screw clamp), no set screw marking on the shaft |
| Outer diameter range | 19 mm to 82 mm |
| Bore range | 4 mm to 42 mm depending on size |
| Keyway | Keyway machining available on request |
| Backlash | Zero |
| Misalignment | Angular, parallel and axial within the published limits for the size |
| Brand and origin | GND / Guangzhida, Dongguan, China |
| Typical applications | Servo and stepper driven ball screws, linear modules, CNC feed axes, packaging and labelling machines, light robotics |
Available sizes
Each size is ordered with the two bore diameters you need, one for the motor shaft and one for the driven shaft.
| Size (outer diameter x length) | Bore range |
|---|---|
| 19 x 27 mm | 4 to 8 mm |
| 20 x 28.8 mm | 4 to 8 mm |
| 26 x 34.1 mm | 5 to 14 mm |
| 26 x 35 mm | 5 to 14 mm |
| 29 x 34.3 mm | 6 to 14 mm |
| 32 x 41 mm | 6 to 15 mm |
| 33 x 40 mm | 6 to 15 mm |
| 34 x 45 mm | 6 to 16 mm |
| 39 x 50 mm | 8 to 19 mm |
| 44 x 50 mm | 8 to 22 mm |
| 56 x 64 mm | 12 to 32 mm |
| 68 x 75 mm | 14 to 38 mm |
| 82 x 98 mm | 17 to 42 mm |
How to order
Couplings are quoted per order, with no price shown on the site. Send us the series GL, the outer diameter and length you need, and the two bore diameters, for example GL-39X50 with 10 mm and 12 mm bores. If you do not know which size fits, send the motor shaft diameter, the driven shaft diameter, the torque and the space available between the two shafts, and our engineers select it for you. RendatSP ships to Saudi Arabia, Iraq, the UAE, Egypt, Oman, Libya, Morocco, Mauritania, Yemen, Algeria, Jordan and Syria.
Frequently asked questions
What is the difference between a clamp hub and a set screw hub?
A clamp hub is split and squeezed onto the shaft by screws, so the grip is spread around the whole shaft and nothing digs into it. A set screw presses a single point onto the shaft, which marks it and can loosen under reversing loads. For servo axes that reverse constantly, the clamp hub is the better choice, and it is what the GL series uses.
Is aluminium strong enough, or should I take the steel version?
Aluminium is lighter, so it adds less inertia to the motor, which helps fast indexing axes. Where the torque is high or the machine is heavy, the 45# steel GLTB series carries more torque in the same outer diameter. Tell us the motor rating and we recommend one or the other.
Does it need a keyway?
No. The clamp hub grips a plain shaft. If your shaft already has a key, we can machine a matching keyway in the bore as an extra operation.
How much misalignment can it take?
A double-disc coupling of this type handles angular and axial misalignment comfortably and a small parallel offset. Exact limits depend on the size, so send us the size and we give the published figures.
Which size do I need?
Start from the two shaft diameters, then pick the smallest outer diameter whose bore range covers both. Check that the overall length fits the gap between the shaft ends, and confirm the torque. Send us those numbers and we do the selection for you.
