Flange star elastic couplings are essential for heavy-duty industrial applications requiring zero-backlash torque transmission and secure flange connections. The DJ-F series from Apex Coupling offers five structural types (A, B, C, D, and E) to suit diverse mounting requirements, with torque ratings from 70 to 23500 N·m.

This guide explains how flange star elastic couplings work, the advantages of each structural type, and how to select the right model for your application.

1. What Is a Flange Star Elastic Coupling?

A flange star elastic coupling consists of:

• Two flanged hubs – precision-machined from 45# steel

• A star-shaped polyurethane elastomer – provides zero-backlash torque transmission and vibration damping

• Flange connection – secures the coupling to heavy machinery

The star-shaped elastomer transmits torque while absorbing shock, dampening vibration, and compensating for misalignment. The flange design provides a secure connection to heavy machinery, making it ideal for demanding industrial applications.

💡 Flange star elastic couplings are widely used in heavy machinery, main spindle drives, lifting platforms, and machine tools.

2. Structural Types – Which One Do You Need?

The DJ-F series is available in five structural types to suit different mounting requirements:

✅ Types B and D feature a double flange structure that allows for radial installation without moving the equipment at either end – enabling quick replacement of the elastomer body.

3. Double Flange Advantage – Radial Installation

The double flange structure (Types B and D) offers a significant maintenance advantage:

4. Key Advantages of DJ-F Couplings

5. How to Select the Right DJ-F Model

Step 1: Choose the Structural Type

• Type A or E: Standard flange-to-shaft connection.

• Type B: Double flange, radial installation – quick elastomer replacement.

• Type C: Flange + shaft, compact outer diameter – space-constrained.

• Type D: Double flange, custom flange – special requirements.

Step 2: Determine Your Torque Requirement

• Calculate the torque your application requires.

• Select a model with rated torque ≥ 1.5× your requirement.

• DJ-F series covers 70–23500 N·m.

Step 3: Match Shaft Diameters

• Measure your shaft diameters.

• Select a model with a bore range that accommodates your shafts.

• H7 bore tolerance is recommended for precision fit.

Step 4: Consider Speed Requirements

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

• DJ-F series offers speeds up to 14000 RPM.

Step 5: Consider Space Constraints

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

• DJ-F series offers compact sizes from 55 mm OD.

Step 6: Consider Keyway and Flange Requirements

• For applications requiring keyways, specify when ordering.

• For special flange requirements, choose Type D.

6. Applications Where DJ-F Couplings Excel

7. Real‑World Example – Heavy Machinery Upgrade

A heavy machinery manufacturer was experiencing downtime due to difficult elastomer replacement on their existing couplings. The standard flange couplings required disassembly of connected equipment for maintenance.

They switched to Apex Coupling DJ-F Type B double flange star coupling (radial installation, quick elastomer replacement). Results:

• Maintenance time reduced – radial installation without moving equipment

• Downtime reduced – quick elastomer replacement

• Performance improved – zero backlash

• Maintenance eliminated – no lubrication required

8. Installation & Maintenance Tips

1. Choose the right type – Type B or D for radial installation without moving equipment.

2. Clean flanges – Remove debris before installation.

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

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

5. Periodic inspection – Check elastomer condition periodically.

6. Quick replacement – For Types B and D, replace elastomer radially without moving equipment.

9. Selection Checklist

• □ 

  Type: A, B, C, D, or E – choose based on mounting requirements

• □ 

  Model: DJ24F to DJ180F – select based on torque and bore requirements

• □ 

  Material: 45# steel – high strength, durable

• □ 

  Backlash: Zero backlash – precision applications

• □ 

  Bore: H7 tolerance – match your shaft diameters

• □ 

  Torque: 70-23500 N·m – ensure it exceeds your requirement

• □ 

  Speed: Up to 14000 RPM – match your motor speed

• □ 

  Flange: Standard or custom (Type D)

• □ 

  Maintenance: Maintenance-free – no lubrication

• □ 

  Application: Heavy machinery, machine tools, lifting platforms, compressors

10. Conclusion

The DJ-F flange star elastic coupling from Apex Coupling offers the perfect combination of zero backlash, secure flange connection, and flexible mounting options for heavy-duty industrial applications. With five structural types, 70-23500 N·m torque capacity, and double flange radial installation for quick maintenance, it is the ideal solution for heavy machinery, main spindle drives, lifting platforms, and machine tools.

👉 Need a flange star elastic coupling for your application? Contact us with your type, model, bore, and torque requirements.