| Coupling Size | Torque Nm | Max. Speed (RPM) | Bore Dia MIN | Bore Dia MAX | QTY N | A | B | C | D | E | F |
|---|---|---|---|---|---|---|---|---|---|---|---|
| FBC 2A | 516 | 4400 | 16 | 45 | 6 | 130 | 105 | 51 | 3 | 67 | 70 |
The Flexible Bolt Coupling FBC 2A represents a significant step up in power density within the FBC series. While maintaining a relatively compact footprint, it utilizes a six-pin design to handle substantially higher torque loads than the standard FBC 2, making it the preferred choice for heavy-duty industrial applications where shaft diameters reach up to 45 mm.
Nominal Torque Capacity: 516 Nm
Maximum Speed: 4,400 RPM
Bore Diameter Range: 16 mm – 45 mm
Quantity of Pins (N): 6
Outer Diameter (A): 130 mm
Overall Length (B): 105 mm
The FBC 2A operates on the same proven pin-and-bush principle but utilizes six high-tensile steel pins. This increase in pin count (N=6) allows the coupling to distribute the 516 Nm torque load across more surface area of the elastomeric bushes.
As the driving flange turns, the six pins compress their respective rubber or urethane bushes against the holes in the driven flange. This compression provides the necessary "give" to accommodate axial float, angular misalignment, and parallel offset without creating the high reaction forces that would otherwise damage motor bearings or mechanical seals.
High Torque-to-Weight Ratio: Delivers over 500 Nm of torque in a 130 mm diameter package, perfect for space-constrained machinery.
Superior Damping: The six-bush arrangement provides enhanced vibrational damping, making it ideal for systems with high torsional fluctuations.
Increased Bore Capacity: Accommodates larger shafts (up to 45 mm) commonly found on high-output electric motors and gear reducers.
Simplified Maintenance: Like the rest of the FBC range, the 2A requires no lubrication. The bushes can be replaced individually, extending the total service life of the coupling flanges.
Operational Safety: The multi-pin design ensures redundant power transmission paths; the failure of a single bush will not cause an immediate total loss of drive.
Heavy-Duty Centrifugal Pumps: Used in mining, slurry handling, and large-scale industrial water processing.
Large HVAC Blowers: Powering industrial-scale air handling units and cooling towers.
Conveyor Head Pulley Drives: Ideal for heavy-duty material handling in mining or aggregate industries.
Secondary Gearbox Drives: Connecting speed reducers to secondary drive shafts in manufacturing lines.
Hydraulic Pump Drives: Often used to connect large electric motors to high-pressure hydraulic power packs.
Torque Safety Factor: With a nominal rating of 516 Nm, ensure the service factor for "high shock" or "frequent starts" is calculated to prevent premature bush wear.
Rotational Velocity: Note the maximum speed is 4,400 RPM. This is lower than the FBC 1 or 2 due to the increased mass and diameter of the 2A unit.
Alignment Precision: While the 6-pin design is forgiving, maintaining tight alignment tolerances during installation will significantly reduce the frequency of bush replacements.
Dimension "C" (38 mm): Ensure there is sufficient axial space (indicated by the 51 mm hub length in the table) for proper shaft engagement and keyway seating.
The Flexible Bolt Coupling FBC 2A is a powerhouse in a compact frame. By moving to a 6-pin configuration, it offers a robust 516 Nm torque capacity and supports larger 45 mm shafts. It is an excellent choice for engineers seeking a "fit and forget" coupling solution for medium-to-heavy industrial drives where vibration isolation and high torque transmission are paramount.
