Choosing Couplings for Heavy Industrial Drives
Gear, tyre, grid and fluid couplings compared for mills, crushers and conveyors.
A coupling joins the motor or gearbox to the machine and has to pass torque, cope with misalignment and take shock. Heavy drives in rolling mills, crushers, conveyors and kilns each suit a different type. This guide compares the main choices.
1. Gear couplings for very high torque
Gear couplings pass very high torque through toothed hubs and sleeves and tolerate angular misalignment. They suit mill drives, kiln drives and heavy gearboxes. They need lubrication and periodic inspection. They are not torsionally flexible, so they do not damp shock by themselves.
2. Tyre couplings for shock and misalignment
Tyre couplings join two flanges with a flexible rubber tyre. They absorb shock and larger misalignment and the tyre can be changed without moving the machines. They are a common choice for crushers, mills and conveyors.
3. Grid couplings for torque peaks
A steel grid spring sits in slots in two hubs and takes torque peaks and torsional vibration. A greased cover protects the grid. They suit conveyors, mixers and other machines with heavy starts.
4. Fluid couplings for soft starts
A fluid coupling transmits torque through oil, so a loaded conveyor or crusher starts smoothly and overloads are damped. A fusible plug protects against overheating. They are used where the start-up torque would otherwise stress the drive.
5. What to tell your supplier
Give the motor power and speed, the driven machine, the shaft diameters and keyways, the starting duty and any existing coupling nameplate. Where the old coupling is a particular make, send the part number so the spares match.
- Motor power and speed
- Driven machine and duty
- Shaft diameters and keyways
- Starting conditions
- Old coupling make and number
Key Takeaways
- Gear couplings suit very high torque, tyre and grid couplings suit shock
- Fluid couplings give soft starts on loaded conveyors
- Send nameplate and shaft details with the enquiry
This article is general guidance. For a recommendation for your own application, contact our engineering team. Couplings →