GHC series Oldham coupling with anodised aluminium alloy clamp hubs and a polyurethane centre disc. The centre disc slides in cross slots, which lets the coupling take a large parallel offset between the two shafts in a short body, something a disc or beam coupling cannot do. The disc is the only wearing part and acts as a mechanical fuse, so an overload damages a cheap plastic disc rather than the motor or the ball screw. Eleven sizes, outer diameters 16 to 70 mm, bores 4 to 38 mm.
Technical specifications
| Series | GHC |
|---|---|
| Coupling type | Oldham (cross sliding block) coupling |
| Hub material | Aluminium alloy |
| Centre disc material | Polyurethane |
| Surface treatment | Anodised |
| Shaft attachment | Clamp type hub (screw clamp) |
| Outer diameter range | 16 mm to 70 mm |
| Bore range | 4 mm to 38 mm depending on size |
| Misalignment | Large parallel offset, plus angular and axial |
| Wearing part | Centre disc, replaceable without removing the hubs |
| Features | Mechanical fuse behaviour on overload, electrical isolation between shafts, vibration damping |
| Brand and origin | GND / Guangzhida, Dongguan, China |
| Typical applications | Stepper and servo axes where shafts cannot be aligned precisely, linear modules, pumps, printing and textile machinery |
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 |
|---|---|
| 16 x 29 mm | 4 to 6.35 mm |
| 20 x 33 mm | 5 to 8 mm |
| 25 x 39 mm | 5 to 12 mm |
| 32 x 45 mm | 6 to 16 mm |
| 40 x 50 mm | 8 to 19 mm |
| 44 x 46 mm | 8 to 22 mm |
| 50 x 53 mm | 10 to 24 mm |
| 50 x 58 mm | 10 to 24 mm |
| 55 x 57 mm | 12 to 28 mm |
| 63 x 71 mm | 14 to 32 mm |
| 70 x 77 mm | 14 to 38 mm |
How to order
Couplings are quoted per order, with no price shown on the site. Send us the series GHC, the outer diameter and length you need, and the two bore diameters, for example GHC-40X50 with 12 mm and 16 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
When is an Oldham coupling the right choice?
When the two shafts are offset sideways and you cannot realign them, for example a motor bolted to a frame that does not line up perfectly with a ball screw. An Oldham takes that parallel offset without pushing side load into the bearings, which a disc or beam coupling would do.
How often does the centre disc need changing?
It depends on the offset, the speed and the load. Running with a large offset at high speed wears it faster. Plan to keep spare discs on the shelf; they are inexpensive and are replaced without taking the hubs off the shafts.
Does it have backlash?
A new Oldham coupling has very little, but the sliding disc develops some as it wears. For an axis that must hold position exactly over a long service life, choose a disc coupling. For general positioning and where offset is the real problem, an Oldham is the practical answer.
Can I get a different disc material?
Yes. Polyurethane is the standard and gives good wear with some damping. Harder engineering plastics are available where torque matters more than damping. Tell us the application and we advise.
How do I know which size to order?
Pick the smallest outer diameter whose bore range covers both shafts, check the torque, and confirm the overall length fits the gap. Send us the shaft diameters, the torque and the offset you have and we do the selection.
