DJ-SF / DJ-DF Flange Star Elastic Coupling – Zero Backlash, 35-18650 N·m, Maintenance-Free

Factory Direct | 45# Steel Hubs | Polyurethane Star Elastomer | Zero Backlash | 35-18650 N·m Torque | 14000-1800 RPM | Single or Double Flange | Radial Installation (SF Type) | Maintenance-Free | OEM Customizable

The Apexcoupling DJ-SF and DJ-DF series are high-performance flange star elastic couplings designed for heavy-duty industrial applications requiring zero-backlash torque transmission and robust flange connections.

• DJ-SF (Double Flange): Features two flanged hubs connected by a star-shaped polyurethane elastomer. The double flange structure allows for radial installation without moving connected equipment – significantly simplifying maintenance and elastomer replacement.

• DJ-DF (Single Flange): Features one standard hub and one flanged hub, providing a secure flange connection on one side while maintaining a compact design.

Both series feature a star-shaped polyurethane elastomer that provides excellent vibration damping, shock absorption, and misalignment compensation. With maintenance-free operation, compact radial dimensions, and high load capacity, the DJ-SF/DF series is the ideal solution for main spindle drives, lifting platforms, machine tools, compressors, fans, pumps, and heavy industrial machinery.

✅ Zero backlash for precise positioning. Single or double flange options. Double flange (SF) allows radial installation without moving equipment. Maintenance-free – no lubrication required. High load capacity – up to 18650 N·m. Compact radial dimensions.

Key Technical Specifications

🔧 Custom bores and keyways available. Contact us with your specifications.

DJ-SF / DJ-DF Series – Model Range & Specifications

📐 Additional sizes and custom dimensions available upon request. Contact our engineering team for custom sizing.

DJ-SF (Double Flange) vs DJ-DF (Single Flange) – Which One Do You Need?

✅ Choose DJ-SF (double flange) when: You need quick elastomer replacement without moving connected equipment – simply remove the flange and install radially.
Choose DJ-DF (single flange) when: You need a secure flange connection on one side with a more compact design.

Product Structure

1. Two Hubs – Precision-machined from 45# steel. DJ-SF: two flanged hubs. DJ-DF: one flanged hub + one standard hub.

2. Star-Shaped Polyurethane Elastomer – Provides zero-backlash torque transmission, vibration damping, and misalignment compensation.

3. Flange Bolts – Secure the flange connection to heavy machinery.

4. Double Flange (SF) Advantage – Allows radial installation without moving connected equipment.

💡 How it works: The DJ-SF/DF coupling consists of two hubs (one or both flanged) with a star-shaped polyurethane elastomer between them. Power is transmitted through the elastomer, which flexes to absorb shock, dampen vibration, and compensate for misalignment. The flange design provides a secure connection to heavy machinery, while the double flange structure (SF) enables radial installation for quick elastomer replacement without moving connected equipment. The zero backlash design ensures precise positioning, while the maintenance-free polyurethane elastomer requires no lubrication.

Product Features & Advantages

Applications

• Heavy Machinery – Flange-connected industrial equipment

• Main Spindle Drives – CNC machine tools, machining centers

• Lifting Platforms – Scissor lifts, aerial work platforms

• Machine Tools – Lathes, milling machines, grinding machines

• Compressors – Air and gas compressors

• Fans & Blowers – Industrial ventilation systems

• Pumps – Centrifugal, gear, and diaphragm pumps

Why Choose Apex Coupling for DJ-SF/DF Flange Star Couplings?

FAQ

Q: What is the difference between DJ-SF and DJ-DF?
A: DJ-SF (Double Flange) – two flanged hubs, allows radial installation without moving equipment. DJ-DF (Single Flange) – one flanged hub, one standard hub, axial installation.

Q: What is the advantage of the double flange structure (SF)?
A: The double flange structure allows for radial installation without moving the equipment at either end – enabling quick replacement of the elastomer body without disassembling the connected machinery.

Q: Does the coupling have backlash?
A: No. The DJ-SF/DF series features zero backlash – no rotational clearance, ensuring precise positioning.

Q: What materials are used?
A: The hubs are made of 45# steel. The elastomer is made of high-strength polyurethane (PU) with 98 Shore A hardness.

Q: Is the coupling maintenance-free?
A: Yes. The DJ-SF/DF series is maintenance-free – no lubrication required.

Q: What is the operating temperature range?
A: The operating temperature range is -35°C to +80°C.

Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores and keyways available.

Request a Quote

Send us your type (SF double flange or DF single flange), model (e.g., DJ55F), bore size, torque, speed, and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours.