Why High-elastic Couplings Are Damaged?

High-elastic couplings are mainly used in flexible couplings of master-slave shafting elastic in machinery. Elastic component 1 of circumference is connected to master-slave hub body 4 and 5 of the couplings, annular free deformation space between master-slave hub body of the couplings is made up of helical circular elastomer of the elastic element by multi-strand twisted wires through metal splint. Master-slave hub body of the couplings constitutes the elastic displacement compensation characteristics by annular free deformation space in the direction of axial, radial and axial tilt. High-elastic couplings are suitable for shaft connection of all kinds of power plants (especially those with single or double elastic vibration isolation foundation) of drives like marine main, auxiliary engines, internal combustion engines, diesel engines, motors and hydraulic motors. 

Recently torsional vibration test is carried out on the ship, according to the test results, torsional vibration characteristics of the coupling of is very small compared to the allowable value, but damages continuously occurred to couplings. Besides its own quality problems and torsional vibration, what factors will lead to damages of coupling generally?

Principle: major elastic elements of high-elastic couplings are mainly reverse bearing rubber components that can be designed into single or multiple rows. There are a variety of standard stiffness of rubber components to select, thus the requirements of the calculated stiffness of torsional vibration can be met greatly. The main purpose of using high elastic couplings in ship power system is to transmit power and torque, compensate radial direction, axial direction and angle to the error, compensate oscillations of rotating momentum and adjust natural frequency of vibration of the system. High-elastic couplings have characteristic of light weight, easy installation, large amount of compensation of displacement, large damping, high ability of vibration absorbing and frequency modulation, which can protect main engine, gearbox and shaft system better.

Reason analysis:
Host elastic shock absorber sinks and causes misalignment of the shaft, generating additional torque, which is of high possibility for new marine. 
Fever fracture occurs to rubber elements of high-elastic couplings.
Matching problem: only all equipments in the shafting such as diesel engines, high-elastic couplings, gear box, other parts, propeller shafts, etc, all have good design and complement and support each other,  all raise their the level of design and manufacture, can high quality ships in the true sense will be designed.

Why High-elastic Couplings Are Damaged?