Mechanical Flexible Couplings

Types of Mechanical flexible couplings 

Gear Couplings 

A common type of mechanical flexible coupling is gear coupling. Each coupling consists of two externally toothed crowned hubs. The hubs engage in two internally toothed collar bushings that are screwed together. Because of the generally enormous size of the teeth, they are called gears. These couplings are typically limited to precise 4° to 5° misalignment. The gear coupling offers good torque properties. Gear couplings transmit the greatest torque and torque in the smallest diameter of any flexible coupling. Gear couplings must be lubricated regularly depending on the application. These couplings have a service life of 3-5 years and can sometimes last for decades. 

Roller Chain Couplings 

Roller Chain Couplings consist of two hubs with radial sprockets that engage a stub of double pitch roller chain. These couplings are used for low to medium speed and torque applications. The engagement of the sprocket and chain teeth transmits torque and the associated clearances accommodate parallel angular and axial misalignment. These couplings can also accommodate up to 2 degrees of misalignment. They have flanges connected to duplex roller chains, giving them a high strength rating roller chain couplings are considered an economical way to transfer power between shafts.

Grid Couplings 

Grid couplings are multi-piece mechanical couplings used to transmit torque and rotation between shafts in mechanical power transmission assemblies. Grid couplings consist of two hubs with radial slots, a grid spring element and a split cover set. These types of flexible couplings are a popular choice when there are high torque and damping requirements. Grid Couplings have the unique ability to reduce vibration by up to 30% and absorb shock loads to protect the drive and power transmission equipment powered by the Grid clutches transmit torque and accommodate angular, parallel and axial misalignment from one hub to another by reciprocating a conical grid in the clutch hub splines. 

Slip Block Couplings (Oldham)

Oldham couplings consist of three discs, one on the inlet, one on the outlet, and a centre disc that engages 90° offset slots between the tongue and groove. These couplings can accommodate lateral shaft misalignments of up to 10% of the nominal shaft diameter and up to 3 angular misalignments. Some manufacturers claim they can tolerate angular misalignment of up to 5 degrees by using cylindrical sliders instead of rectangular ones. Lubrication is an issue, but they can be overcome by choosing a hard-wearing plastic or elastomer instead of steel or bronze floating elements.