| Coupling Size | Torque Nm | Max. Speed (RPM) | Bore Dia MIN | Bore Dia MAX | QTY N | A | B | C | D | E | F |
|---|---|---|---|---|---|---|---|---|---|---|---|
| FBC 8A | 7268 | 1650 | 60 | 138 | 18 | 340 | 265 | 130 | 5 | 205 | 130 |
The Flexible Bolt Coupling FBC 8A is a high-capacity evolution of the 8-series frame, utilizing an eighteen-pin configuration (N=18) to deliver a significant boost in torque transmission. Engineered for heavy industrial power plants, it provides a massive 7,268 Nm of torque capacity while maintaining a compact axial profile for its power class.
Nominal Torque Capacity: 7,268 Nm
Maximum Speed: 1,650 RPM
Bore Diameter Range: 60 mm – 138 mm
Quantity of Pins (N): 18
Outer Diameter (A): 340 mm
Overall Length (B): 265 mm
The FBC 8A utilizes eighteen high-tensile steel pins distributed around a reinforced 340 mm diameter flange. This high pin density is specifically designed to manage the extreme shear forces generated by a 7,268 Nm load.
The torque is transferred through the simultaneous compression of 18 elastomeric bushes. By spreading the load across a higher number of points than the standard FBC 8, the 8A model reduces the "per-bush" stress, which is vital for maintaining torsional stability and longevity in high-torque, continuous-duty cycles. The design accommodates misalignment and provides a 5 mm axial gap (Dimension D) to protect the bearings of massive industrial motors.
Maximum Torque Density: Delivers nearly 7.3 kNm of torque, making it one of the most powerful couplings in the 340 mm diameter range.
Exceptional Redundancy: With 18 pins in operation, the coupling offers the highest level of fail-safe reliability in the 8-series; the system remains balanced even if individual bushes begin to age.
Large Bore Support: Accommodates massive shafts up to 138 mm, common in large-scale gearboxes and high-output industrial motors.
Vibration Dampening: The 18-bush configuration provides a highly effective "soft" interface that absorbs the heavy shocks and harmonic vibrations found in primary industrial drives.
Maintenance-Free: Operates without grease or oil, preventing the buildup of abrasive sludge in dusty environments like mines or cement plants.
Primary Crushers and Mills: Used in mining and aggregate processing where massive torque and shock loads are constant.
Heavy-Duty Dredging Pumps: Ideal for high-volume slurry and sand transport in marine and civil engineering.
Main Drive Gearboxes: Connecting high-horsepower motors to primary reduction gearboxes in heavy manufacturing.
Large Scale Agitators: Powering industrial-scale mixing vessels in the petrochemical and polymer industries.
Overland Conveyors: Providing the necessary starting torque for kilometer-long bulk material handling systems.
Speed Limits: The maximum speed is reduced to 1,650 RPM. This is optimized for 4-pole or 6-pole motors; it is not suitable for high-speed turbine or 2-pole motor applications.
Hub Engagement (Dimension C): The 130 mm hub depth requires a long shaft extension. Ensure the keyway is precision-cut to handle the 7,268 Nm load without localized deformation.
Weight and Handling: At 340 mm in diameter, the FBC 8A is a heavy component. Professional rigging and precision laser alignment are essential to ensure all 18 pins share the load equally.
Thermal Expansion: Monitor the 5 mm gap during installation to ensure that as the large shafts heat up and expand, the hubs do not make metal-to-metal contact.
The Flexible Bolt Coupling FBC 8A is a heavy-duty powerhouse, offering a massive 7,268 Nm torque capacity and supporting bores up to 138 mm. Its 18-pin design provides the ultimate level of load-carrying capability and vibration isolation for large-scale industrial machinery where reliability is the primary concern and maintenance access may be limited.
