Flender ZAPEX ZNN 280 Heavy-Duty Gear Coupling
The Flender ZAPEX ZNN 280 is a heavy-duty double-gimbal curved-tooth gear coupling engineered for ultra-high torque transmission in compact industrial drivetrains[cite: 20]. Featuring precision-machined crowned teeth[cite: 20], the ZAPEX ZNN 280 delivers a nominal torque rating of 62,000 Nm (peak capacity up to 140,000 Nm) while accommodating angular, parallel, and axial shaft misalignments with minimal restoring forces[cite: 20]. Covering 20 frame sizes from size 83 to 1000 (1,020 Nm to 7,200,000 Nm)[cite: 20], ZAPEX couplings feature standard double-engagement designs (ZNN), extended axial float units (ZNA), single-engagement cardan drives (ZNNA), attached brake discs (ZWB/ZNNB), high-speed steel designs (ZWS), and vertical executions (ZWNV)[cite: 20]. They are heavily specified in steel rolling mills, continuous casting lines, crane hoists, cement kilns, marine propulsion, and mining winches[cite: 20].
Technical Specifications
| Model / Part Number | ZAPEX ZNN 280 (Type ZNN, Size 280 Double-Engagement)[cite: 20] |
|---|---|
| Brand / Manufacturer | Flender GmbH[cite: 20] |
| Structural Execution | Type ZNN (Standard double-engagement all-steel gear coupling)[cite: 20] |
| Nominal Torque Output | 62,000 Nm (Size 280) / 1,020 Nm to 7,200,000 Nm (Full Series Range)[cite: 20] |
| Misalignment Capability | Angular misalignment up to ±1.5° per gearing half[cite: 20] |
| Lubrication & Seals | High-performance synthetic grease / oil with DUO double radial shaft seals[cite: 20] |
| ATEX Certification | Certified according to 2014/34/EU Directive for explosive atmospheres (Zone 1/21 & 2/22)[cite: 20] |
| Construction Material | High-tensile forged alloy steel sleeve and crowned tooth hubs[cite: 20] |
Documentation & Resources
Flender ZAPEX Series Modular Architecture Matrix
Full-range structural configuration guide for Flender ZAPEX heavy-duty curved-tooth gear couplings[cite: 20]. Review supported execution types, brake disc attachments, high-speed steel designs, and vertical layouts:
| Coupling Type & Structural Execution | Frame Sizes Covered | Nominal Torque Rating (Nm) | Key Operational Advantages & Applications |
|---|---|---|---|
| ZAPEX Type ZNN (Standard Double-Engagement)[cite: 20] | Size 83 to Size 1000 (20 Sizes)[cite: 20] | 1,020 Nm - 7,200,000 Nm[cite: 20] | Universal High Torque (Mill stands & heavy drives)[cite: 20] |
| ZAPEX Type ZNA (Extended Shaft Distance)[cite: 20] | Size 83 to Size 800 (18 Sizes)[cite: 20] | 1,020 Nm - 3,500,000 Nm[cite: 20] | Extended DBSE (Accommodates large shaft spacing)[cite: 20] |
| ZAPEX Type ZWB / ZNNB (With Brake Disc)[cite: 20] | Size 107 to Size 530 (13 Sizes)[cite: 20] | 2,000 Nm - 350,000 Nm[cite: 20] | Brake Integration (Heavy crane hoist & winch brakes)[cite: 20] |
| ZAPEX Type ZWS / ZWNV (High Speed & Vertical)[cite: 20] | Size 83 to Size 530 (14 Sizes)[cite: 20] | 1,020 Nm - 350,000 Nm[cite: 20] | High Speed / Vertical (Pump shafts & turbomachinery)[cite: 20] |
| ZAPEX Type ZND / ZNH (Intermediate Spacers)[cite: 20] | Size 107 to Size 400 (10 Sizes)[cite: 20] | 2,000 Nm - 160,000 Nm[cite: 20] | Spacer Sleeves (Eases motor / pump disassembly)[cite: 20] |
Legacy Gear Coupling Replacement & ZAPEX Upgrade Guide
Worn toothed gear couplings installed on rolling mills, cement kilns, and crane hoists can be directly replaced with Flender ZAPEX high-capacity couplings[cite: 20]. Refer to the replacement mapping below for 1-to-1 retrofitting:
| Legacy Coupling Series / Type | Coupling Mechanism | Current ZAPEX Equivalent Model | Torque Capacity | Mechanical Fit & Retrofit Engineering Notes |
|---|---|---|---|---|
| Legacy ZAPEX Size 280 Type ZNN[cite: 20] | Curved Gear Tooth[cite: 20] | ZAPEX Type ZNN 280 Current Standard[cite: 20] | 62,000 Nm[cite: 20] | Direct 1-to-1 flange bolt circle & gear tooth pitch match[cite: 20]. |
| Conventional Straight Gear Couplings[cite: 20] | Straight Spur Gearing[cite: 20] | ZAPEX Type ZNN 210 / 240 / 280 Crowned Tooth[cite: 20] | 28,000 Nm - 62,000 Nm[cite: 20] | Crowned tooth profile eliminates edge pressure and extends life[cite: 20]. |
| Steel Mill Roll Stand Drives[cite: 20] | High Torque Gear Sleeve[cite: 20] | ZAPEX Type ZNN 280 / 320 / 360 Mill Duty[cite: 20] | 62,000 Nm - 140,000 Nm[cite: 20] | Transmits extreme reversing impact loads in rolling mills[cite: 20]. |
| Heavy Crane Hoist Winch Drives[cite: 20] | Gear Coupling with Brake[cite: 20] | ZAPEX Type ZWB / ZNNB 280 + Brake Brake Disc[cite: 20] | 62,000 Nm[cite: 20] | Forged steel hub with integrated caliper brake disc[cite: 20]. |
| Vertical Pump & Mixer Shafts[cite: 20] | Standard Horizontal Gear[cite: 20] | ZAPEX Type ZWNV 280 Vertical Vertical Duty[cite: 20] | 62,000 Nm[cite: 20] | Special DUO oil retention seals prevent lubricant leakage[cite: 20]. |
Expert Selection & Retrofit Engineering Notes
When servicing existing installations featuring worn gear teeth or leaking seals, we stock genuine Flender ZAPEX crowned tooth hubs, flanged sleeves, and DUO double radial seal kits[cite: 20]. Simply supply us with your coupling size, bore diameters, distance between shaft ends (DBSE), and operating torque, and our engineering team will deliver a 100% compliant replacement specification and proposal[cite: 20].
Core Benchmark Model Standard Configurations
- ZAPEX Type ZNN 130[cite: 20]
- ZAPEX Type ZNN 180[cite: 20]
- ZAPEX Type ZNN 210[cite: 20]
- ZAPEX Type ZNN 240[cite: 20]
- ZAPEX Type ZNN 280[cite: 20]
- ZAPEX Type ZNN 320[cite: 20]
- ZAPEX Type ZNN 360[cite: 20]
- ZAPEX Type ZNN 400[cite: 20]
- ZAPEX Type ZNN 480[cite: 20]
- ZAPEX Type ZNA 280 (Long DBSE)[cite: 20]
- ZAPEX Type ZNNA 280 (Single Eng.)[cite: 20]
- ZAPEX Type ZWB 280 (Brake Disc)[cite: 20]
- ZAPEX Type ZWS 280 (High Speed)[cite: 20]
- ZAPEX Type ZWNV 280 (Vertical)[cite: 20]
- ZAPEX Type ZND 280 (Spacer)[cite: 20]
- ZAPEX Crowned Hub Size 280[cite: 20]
- ZAPEX Flanged Sleeve Size 280[cite: 20]
- ZAPEX DUO Seal Kit Size 280[cite: 20]
- ZAPEX O-Ring Kit Size 280[cite: 20]
- Flender High-Load Gear Grease[cite: 20]
