Maintenance-Free NM Couplings | Flexible Jaw Couplings for Shaft Connection
Need a durable, maintenance-free solution to connect your drive and driven shafts? Donghua's NM couplings (also known as flexible jaw couplings) are engineered to transmit motion smoothly while compensating for misalignment, reducing vibration, and protecting your equipment. As a comprehensive power transmission manufacturer since 1991, we offer reliable couplings that complement our world-class chains and sprockets.
What is an NM Coupling?
An NM coupling is a mechanical component used to connect two shafts together for the purpose of transmitting power. Its key advantage is its ability to compensate for minor misalignments between shafts-whether axial, radial, or angular-that can occur due to manufacturing tolerances, installation inaccuracies, or thermal expansion during operation. This helps to:
- Protect Machinery: Reduces stress on bearings, seals, and other components.
- Dampen Vibration: Absorbs shock loads and torsional vibrations.
- Ensure Smooth Operation: Maintains power transmission even with slight shaft movement.
Key Specifications of Our NM Couplings
| Specification | Details |
|---|---|
| Available Sizes | Nm50, 67, 82, 97, 112, 128, 148, 168, 194, 214 |
| Hub Material | Cast Iron (with zinc die-cast options) |
| Flexible Element Material | NBR (Nitrile Rubber) – resistant to oil, grease, moisture, ozone, and many solvents. Also available in other materials like Nomex. |
| Spring Material (for certain types) | C-type spring steel, zinc-plated |
| Features | Anti-static, Corrosion-Resistant, Wear-Resistant |
| Surface Treatment | Baking Paint |
| Temperature Range | -40°C to +120°C |
| Applications | Textile Machinery, Food Machinery, Agricultural Machinery, and general industrial drives. |
| Standards | Flexible all-metal construction, suitable for both rotation directions. |
| Bore Options | Available pre-drilled from stock. Custom bores and keyways available at additional cost. |
Construction & Benefits
Our NM couplings consist of two hubs and a flexible ring (or spring body). This simple yet effective design offers several advantages:
- All-Metal / Hybrid Options: Available with hubs made from durable cast iron or zinc die-cast, and flexible elements made from high-performance NBR rubber or stainless spring steel.
- Maintenance-Free Operation: No lubrication or regular maintenance is required, reducing downtime and operating costs.
- Easy Installation: Locked against rotation with a hexagon socket set screw. Custom bores and keyways can be machined to your exact requirements.
- Versatility: Suitable for a wide range of industrial applications, from textile and food machinery to agricultural equipment.
- Comprehensive Supplier: Donghua is not just a chain manufacturer. We are a complete power transmission solution provider, offering complementary products like NM couplings, sprockets, gears, and more. This means you can consolidate your sourcing and rely on consistent quality across your entire drive system.
- Engineering Excellence: With over 30 years of experience, five domestic subsidiaries, and a global presence, our engineering team understands how components work together. Our couplings are designed and manufactured to the same high standards as our world-leading chains.
- Quality Assured: We use high-quality materials (like NBR for flexibility and durability) and precision manufacturing processes to ensure our couplings provide long-lasting, reliable service in demanding environments.
Features: Anti-Static Corrosion-Resistant Wear-Resistant
Scope of application: Textile Machinery Food Machinery Agricultural Machinery
Surface treatment: Baking Paint
Material：cast iron
Size：Nm50 67 82 97 112 128 148 168 194 214
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