1. Introduction

Servo motors demand couplings that deliver zero backlash, high torsional stiffness, and reliable performance under dynamic loads. Double diaphragm couplings with keyless taper clamp (shrink disc) connections, like the DBL41 series, are gaining popularity in demanding applications. This article explains their advantages and when to specify them.

2. What is a Keyless Taper Clamp (Shrink Disc)?

A keyless taper clamp (also called shrink disc or locking assembly) uses mechanical interference to lock a coupling hub onto a shaft without keyways or set screws. Tightening the clamp bolts generates radial clamping force, securing the hub in place.

3. Advantages of Keyless Taper Clamp Diaphragm Couplings

4. Single vs. Double Diaphragm – What’s the Difference?

5. When to Choose a Keyless Taper Clamp Diaphragm Coupling

• High-torque servo systems (e.g., 400 N·m and above)

• Applications requiring frequent disassembly for maintenance

• High-speed positioning (up to 15,000 rpm)

• Reversing operations where zero backlash is critical

• Shafts without keyways or where keyway machining is undesirable

6. Installation Best Practices

1. Clean shaft and coupling bore thoroughly

2. Lightly oil clamp bolts (do not oil tapered surfaces)

3. Slide coupling onto shaft to desired position

4. Tighten clamp bolts progressively in a star pattern to specified torque

5. Verify concentricity and runout after installation

7. Why Apexcoupling DBL41 Series

• High-strength 45# steel hubs

• 304 stainless steel double diaphragm

• Precision H7 bores

• Factory-direct pricing and customization

• Technical support for selection and installation

8. Conclusion

For demanding servo motor applications requiring high torque, zero backlash, and easy installation, a double diaphragm coupling with keyless taper clamp is an excellent choice. Contact Apexcoupling for assistance with sizing and customization.

Check double diaphragm coupling for details.