Oldham couplings (also known as cross slider couplings or sliding disc couplings) are essential for precision power transmission in applications requiring large radial misalignment compensation, low inertia, and zero backlash. With a simple three-component design – two aluminum hubs and a center slider – they offer an excellent balance of performance, reliability, and ease of maintenance.

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 hubs – typically aluminum alloy, 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.

2. Key Advantages of Oldham Couplings

3. When to Choose an Oldham Coupling

Choose an Oldham coupling if your application requires:

• Large radial misalignment – Shafts with significant lateral offset

• Low inertia – High-speed, rapid acceleration/deceleration

• Zero backlash – Precision positioning, servo systems

• Electrical isolation – Between driving and driven shafts

• Simple maintenance – Easy slider replacement without moving hubs

Typical applications: Servo motors, stepper motors, encoders, resolvers, tachometers, positioning slides, dosing pumps, actuators, and potentiometer drives.

4. Material Selection – Aluminum Hubs + PA66 Slider

✅ The combination of aluminum hubs and PA66 slider provides the perfect balance of strength, low inertia, and long service life.

5. Short Clamping Design – Low Inertia Advantage

The DGHS series features a short clamping design that provides:

• Low moment of inertia – Enables rapid acceleration and deceleration

• Compact length – Saves space in tight installations

• Clamping screw fastening – Secure shaft connection, easy installation

6. Misalignment Compensation – Protecting Your Equipment

The DGHS series compensates for two types of misalignment:

By absorbing these deviations, the coupling reduces stress on bearings and seals – extending equipment life.

7. Zero Backlash – Why It Matters

Zero backlash is critical for:

• Servo motors – Precise positioning and speed control

• Stepper motors – No lost steps

• Encoders – Accurate position feedback

• Precision positioning systems – Repeatable motion

8. Applications Where Oldham Couplings Excel

9. Real‑World Example – Servo Motor Upgrade

A machine builder was experiencing positioning errors on a servo-driven indexing table due to backlash in their existing coupling. The coupling also had high inertia, limiting acceleration.

They switched to Apex Coupling DGHS cross slider coupling (aluminum hubs, PA66 slider, short clamping, zero backlash). Results:

• Positioning accuracy improved – backlash eliminated

• Acceleration increased – low inertia enabled faster response

• Maintenance eliminated – no lubrication required

• Electrical isolation – PA66 slider prevented ground loops

10. Installation & Maintenance Tips

1. Clean shaft and bore – Remove oil, grease, and debris

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

3. Tighten clamping screws evenly – Use a torque wrench in a star pattern

4. No lubrication required – PA66 slider is self-lubricating

5. Inspect slider periodically – Replace if worn or damaged

6. Detachable design – Replace slider without moving hubs

11. Selection Checklist

• Material: Aluminum alloy hubs + PA66 slider – standard

• Design: Short clamping – low inertia

• Backlash: Zero backlash – precision applications

• Misalignment: Radial and angular compensation

• Bore size: 3–16 mm – match your shaft diameters

• Torque: 500 N·m – select based on your requirement

• Speed: 1000 RPM – match your motor speed

• Application: Servo, stepper, encoder, pump, positioning

12. Conclusion

The DGHS aluminum alloy cross slider coupling from Apex Coupling offers the perfect combination of large radial misalignment compensation, low inertia, zero backlash, and maintenance-free operation for precision motion control applications. With aluminum alloy hubs, imported PA66 slider, short clamping design, and OEM customization, it is the ideal solution for servo motors, stepper motors, encoders, pumps, and positioning systems.

👉 Need a cross slider coupling for your precision application? Contact us with your bore size, torque, and speed requirements.