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When misalignment between a servomotor shaft and a driven component causes vibration, premature wear, or positioning errors, the coupling becomes the critical link. Engineers and CNC machine builders who demand repeatable accuracy need a coupling that absorbs angular and axial misalignment without introducing backlash or compliance that degrades closed-loop performance.
This single diaphragm CNC coupler is machined from aluminium alloy with an outer diameter of 82 mm (approx. 3.23 in) and a body length of 68 mm (approx. 2.68 in). The bore range spans d14 mm to d45 mm (approx. 0.55 in to 1.77 in), covering a wide selection of servomotor and ballscrew shaft diameters. The diaphragm disc element transmits torque while accommodating misalignment, and clamping hubs secure the shaft without set-screw damage.
Typical applications include servo-driven ballscrew assemblies on CNC milling machines, direct-drive encoder mounting on rotary stages, and flexible coupling replacement in servo press and pick-and-place automation where single diaphragm aluminium shaft couplings must maintain angular stiffness under dynamic load reversals.
The single diaphragm disc transmits torque rigidly in the rotational direction while flexing to absorb angular and axial misalignment — eliminating the backlash that degrades servo positioning accuracy.
Machined from aluminium alloy for a low moment of inertia that reduces servo motor load, while maintaining the structural rigidity needed for dynamic torque transmission in CNC applications.
Covers the most common servomotor and ballscrew shaft diameters in a single product family. Select the exact bore combination that matches your d1 and d2 shaft sizes from the variant options.
Split-clamp hubs grip the shaft circumferentially without point-loading, protecting shaft surfaces and allowing precise axial positioning of the coupling during installation.
The aluminium body resists oxidation in typical workshop and light industrial environments, reducing maintenance requirements compared to steel couplings in humid or coolant-exposed conditions.
Order a single unit for a replacement or prototype build, or select the 2-piece pack for dual-axis machines and to keep a spare on hand — both options ship as a complete, ready-to-install coupling.
| Outer Diameter (OD) | D82 mm (approx. 3.23 in) |
|---|---|
| Body Length | L68 mm (approx. 2.68 in) |
| Bore Range (d1 / d2) | d14 mm – d45 mm (approx. 0.55 – 1.77 in) |
| Coupling Type | Single Diaphragm |
| Material | Aluminium Alloy |
| Shaft Retention | Clamping Hub (Split Clamp) |
| Backlash | Zero (diaphragm element) |
| Finish | See variant options |
| Pack Quantity | 1 pcs or 2 pcs (select via QTY option) |
| Bore Size Selection | See variant options (d1 × d2 combinations) |
Measure the shaft diameter of both your motor (d1) and your driven component such as a ballscrew (d2) using a digital caliper. Then select the variant that matches your d1 × d2 combination. If both shafts are the same diameter, choose a same-bore variant (e.g., d20 – d20). If they differ, choose the variant that lists your two shaft sizes. The option labeled "D82 x L68mm / d14 – d45" covers the full bore range and allows you to specify your bore combination in the order remarks.
Rated torque depends on the specific bore size and operating conditions. For confirmed torque ratings for your exact variant, please contact us to confirm before ordering for high-torque servo applications. As a general reference, D82 aluminium single diaphragm couplings in this size class typically handle continuous torques in the range of 30–80 Nm, but this varies by bore diameter and clamping configuration.
Yes. The single diaphragm disc element transmits torque through a flexible metal membrane rather than through jaw teeth, elastomeric spiders, or Oldham discs — all of which introduce some degree of backlash or compliance. The diaphragm design provides torsional rigidity in the rotational direction while flexing axially and angularly, making it suitable for closed-loop servo positioning systems where backlash would cause following error or oscillation.
Single diaphragm couplings accommodate angular misalignment (typically up to 1°) and axial displacement. They are not designed for large parallel (radial) misalignment. For best performance and diaphragm longevity, align shafts as accurately as possible during installation and use the coupling's flexibility only to absorb residual misalignment rather than to compensate for poor alignment.
The aluminium alloy body resists oxidation well in typical workshop environments and light coolant exposure. For aggressive coolant chemistries or submerged applications, consider applying a compatible protective coating or contact us to confirm suitability. The clamping screws are typically stainless steel or zinc-plated steel — confirm fastener material if corrosion resistance is critical for your environment.
Yes. While the product name references servomotors, the D82 single diaphragm coupling is equally suitable for stepper motors, DC servo drives, and any rotary actuator where zero-backlash torque transmission and misalignment compensation are required. Verify that your stepper motor shaft diameter falls within the d14–d45 mm bore range and select the appropriate variant.
Both options supply the same coupling. The 1 pcs pack is ideal for single-axis builds, replacements, or prototype testing. The 2 pcs pack is suited for dual-axis machines (e.g., X and Y axes on a CNC router), or when you want to keep a spare coupling on hand to minimize downtime. The per-unit price is the same for both pack sizes.
