Grand gear toothed flexible couplings offer reliable and positive means of transmitting mechanical power with ample flexibility to combat various forms of misalignment: angular, offset and combination of angular offset including end float of shafts. Standard double engagement type gear toothed flexible coupling consists of two geared hubs, two outer flanged geared hubs, two outer flanged geared sleeves, a set of bolts, grease nipples and o-rings. The external teeth of the hubs engage with the internal teeth of sleeves and flanges of two sleeves are bolted together hence making the unit a complete coupling. The flexibility in the coupling is provided by specially designed gear teeth configuration to make the coupling self-aligning during operation. The geared hubs are made out of tested forged steel and flanged geared sleeves which are made up of tested forged steel or graded cast steel depending on the size and requirements. The teeth are generated and are of involute form. The bolts are made out of high tensile steel and precision machined. The o-rings are made out of specially bonded rubber to withstand compression and of adequate hardness for a long life. The sleeves and hubs are heat treated to hardness of 240-280 bhn to provide wear-resistance properties for longer life of the couplings. For standard couplings, lubrication is provided by grease which penetrates the tooth contact area to form a thin layer of lubricant to minimise the friction. The grease is injected through grease nipples, it is retained by o-rings provided on both sides.
