Oldham couplings (also known as cross slider couplings or sliding disc couplings) are essential components in precision motion control systems. With their unique sliding design, they provide zero backlash, low inertia, and excellent radial misalignment compensation – making them the ideal choice for servo motors, stepper motors, encoders, and resolvers.

This guide explains how Oldham couplings work, their key advantages, and how to select the right model for your application.

1. What Is an Oldham Coupling?

An Oldham coupling consists of:

• Two aluminum hubs – with axial grooves on their inner faces

• A center slider – engineering plastic (PA66) with matching slots at 90° on each side

As the coupling rotates, the center slider slides within the grooves of the hubs, accommodating radial (eccentricity) and angular misalignment while transmitting torque. The PA66 slider provides electrical insulation between the two shafts, preventing ground loops in sensitive applications.

💡 Oldham couplings are widely used in servo motor, stepper motor, encoder, and resolver applications due to their zero backlash and excellent radial misalignment compensation.

2. Key Advantages of Oldham Couplings

3. Applications Where Oldham Couplings Excel

4. How to Select the Right Oldham Coupling

Step 1: Determine Your Torque Requirement

• Calculate the torque your application requires.

• Select a model with adequate torque capacity.

• DH series covers screw torque from 1.2–8 N·m.

Step 2: Match Shaft Diameters

• Measure your shaft diameters.

• Select a model with a bore range that accommodates your shafts (4–25 mm).

• H7 bore tolerance is recommended for precision fit.

Step 3: Consider Space Constraints

• Measure available space for the coupling (outer diameter and length).

• DH series offers compact sizes from 16 mm OD.

Step 4: Evaluate Misalignment

• Determine the expected radial and angular misalignment.

• Oldham couplings compensate for radial and angular misalignment.

Step 5: Consider Speed Requirements

• Verify the coupling’s maximum speed exceeds your operating speed.

• DH series offers speeds up to 10000 RPM.

Step 6: Consider Electrical Isolation

• The PA66 slider provides electrical insulation – ideal for encoder applications.

5. Installation & Maintenance Tips

1. Clean shafts – Remove oil, grease, and debris before installation.

2. Check alignment – Even with misalignment compensation, keep within recommended limits.

3. Tighten set screws evenly – Use a torque wrench to specification.

4. No lubrication required – Coupling is maintenance-free.

5. Periodic inspection – Check slider condition periodically.

6. Keep clean – Remove dust and debris to prevent premature wear.

7. Slider replacement – Replace slider without moving hubs.

6. Selection Checklist

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  Type: DH – aluminum cross slider (Oldham) coupling

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  Material: Aluminum hubs + PA66 slider

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  Backlash: Zero backlash – precision applications

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  Bore: H7 tolerance – match your shaft diameters

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  Fastening: Set screw – simple and secure

• □ 

  Misalignment: Radial and angular – verify capacity

• □ 

  Speed: Up to 10000 RPM – match your motor speed

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  Maintenance: Maintenance-free – no lubrication

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  Application: Servo motors, stepper motors, encoders, 3D printers

7. Conclusion

The DH aluminum cross slider coupling from Apex Coupling offers the perfect combination of zero backlash, high radial misalignment capacity, and electrical insulation for precision motion control applications. With aluminum alloy hubs, imported PA66 slider, set screw fastening, and maintenance-free operation, it is the ideal solution for servo motors, stepper motors, encoders, and 3D printers.

👉 Need an Oldham coupling for your precision application? Contact us with your model, bore, and torque requirements.