Forged Couplings & Coupling Hubs
A coupling transmits torque between two shafts that are never perfectly aligned. It must carry full torque while accommodating that misalignment without transmitting the resulting loads into bearings.
Forged couplings transmit torque between shafts while accommodating misalignment. Rigid types require near-perfect alignment; flexible types protect bearings from misalignment loads. Bores are machined to H7 with keyways to drawing and dynamic balancing where speed requires it.
- Outside diameter
- 50 mm – 600 mm
- Bore range
- 20 mm – 250 mm
- Materials
- EN8, EN19, EN24
- Bore tolerance
- H7
- Balancing
- Dynamic, where specified
Forged Couplings & Coupling Hubs at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Outside diameter 50 mm to 600 mm
- Bores machined to H7 tolerance
- Dynamic balancing available
- Rigid and flexible types supplied
Torque and Misalignment Together
Rigid couplings carry torque but demand near-perfect alignment. Flexible couplings accommodate angular and parallel misalignment while transmitting torque, protecting bearings from the loads misalignment would otherwise generate.
- Rigid: torque only, needs alignment
- Flexible: accommodates misalignment
- Bore and keyway to drawing
- Dynamically balanced where required
Bore, Keyway and Balance
Bore concentricity to the pitch circle determines whether the coupling runs true. Keyway width and depth transmit torque without hammering oversize. High-speed couplings are dynamically balanced, because residual unbalance at speed loads bearings continuously.
People also ask
Why does coupling bore concentricity matter?
If the bore is not concentric with the pitch circle, the coupling runs out at speed, generating vibration and cyclic bearing loads that shorten bearing life substantially.
What causes coupling keyways to hammer oversize?
Insufficient key contact area, reversing torque, or a loose fit that allows movement. Correct keyway width, depth and fit prevent it.
What sizes of coupling do you manufacture?
50 mm to 600 mm outside diameter with bores from 20 mm to 250 mm, in EN8, EN19 and EN24.
Topics covered on this page
- coupling
- coupling hub
- misalignment
- keyway
- dynamic balancing
- torque transmission
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is the difference between rigid and flexible couplings?
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Rigid couplings transmit torque but require near-perfect shaft alignment. Flexible couplings accommodate misalignment, protecting bearings from the loads it generates.
Do you machine bores and keyways?
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Yes, to H7 bore tolerance with keyways to drawing, gauge verified.
Can couplings be dynamically balanced?
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Yes, to a specified residual unbalance for high-speed applications.