Official UK Distributors for
Couplings
Our couplings work in conjunction with the engine mounts by providing the softest element in the shaft assembly to improve performance and provide a sacrificial link that is designed to fail before gearbox damage occurs.
They are designed to cover a large percentage of gearboxes, such as Twin Disc, ZF, Dong-I, Borg Warner, Bukh, Newage, Paragon, Technodrive, Volvo, Yanmar and many more.
Available with DNV-GL “Type Approval” upon request for vessels in survey.
While designed for marine use, these couplings are used in many industrial driveline applications too.
2 Bolt
Two bolt couplings are used on two bolt hole output flanges. Spigots on these couplings can be either male, female, or none, as determined by the flange. Poly Flex couplings are configured to the flanges.
3 Bolt
Three bolt couplings are used on three bolt hole output flanges. Spigots on these couplings can be either male, female, or none, as determined by the flange. Poly Flex couplings are configured to the flanges.
4 Bolt
Four bolt couplings are used on four bolt hole output flanges. Spigots can be either male or female, as determined by the flange. Poly Flex couplings are configured to the flanges.
The IV range of Poly Flex couplings is specifically developed to operate in a tensile condition created by integral V drives.
6 Bolt
Six bolt couplings are used on six bolt hole output flanges. Spigots can be either male or female, as determined by the flange. Poly Flex couplings are configured to the flanges. Some couplings may need a T bush kit or adaptor to clear obstructions, these can be supplied by Poly Flex.
The IV range of Poly Flex couplings is specifically developed to operate in a tensile condition created by integral V drives.
8 Bolt
Eight bolt couplings are used on eight bolt hole output flanges. Spigots can be either male or female, as determined by the flange. Poly Flex couplings are configured to the flanges. Some couplings may need a T bush kit or adaptor to clear obstructions, these can be supplied by Poly Flex.
10 Bolt
Ten bolt couplings are used on ten bolt hole output flanges. Spigots can be either male or female, as determined by the flange. Poly Flex couplings are configured to the flanges. Some couplings may need a T bush kit or adaptor to clear obstructions, these can be supplied by Poly Flex.
12 Bolt
Twelve bolt couplings are used on twelve bolt hole output flanges. Spigots can be either male or female, as determined by the flange. Poly Flex couplings are configured to the flanges. Some couplings may need a T bush kit or adaptor to clear obstructions, these can be supplied by Poly Flex.
Spicer Series
Spicer or Uni-Joint couplings are used on drive shaft flanges configured to standard Spicer. Spigots can be either male or female, as determined by the flange. These coupling range from four to eight bolt couplings.
Coupling Specs
The Poly Flex flexible drive coupling range is moulded from engineering heat cured polymer alloys of the highest standards and all metal components are plated in SA5 Cobalt Zinc, increasing the metal life that normal zinc plating would give by 600%. All our couplings are machined on a purpose built flange jigs and have a maximum runout of (0.002″ or 0.05mm). Spigots are machined to tolerance within (+/- 0.002″ or +/- 0.05mm). To ensure maximum strength, durability and performance of your flexible coupling strict installation guidelines must be followed which are included with each coupling sold by Poly Flex. The table below (table 1a) is a guide for the recommended torque ratings for the bolts used that screw into our couplings.
Note: Over-tensioning of the bolts that screw into the coupling during assembly may cause internal damage to the Poly Flex coupling and therefore will result in a coupling that will not function properly as it is designed to do so. Poly Flex couplings are sold with anti-seize applied to the thread of the inserted bolts to ensure easy maintenance and removal.
Note: If anti-seize is removed, bolts will seize up over time.
Electrical Isolation
All Poly Flex couplings electrically isolate the shaft and propeller from the engine/gearbox. This can be rectified by installing a shaft strap.
General Maintenance
Misalignment increases stresses on the drive train (gearbox), which decreases the capacity and life of the coupling and causes premature wear of the stern bearings. If the engine is mounted on rubber mounts it is recommended that the alignment is checked every 6 months due to the design and materials used in rubber mounts, which tend to settle. Check every 12 months if the engine is sitting on Poly Flex mounts. Alignment must be carried out while the vessel is in the water and with the flexible coupling removed.