Comparison of elastic sleeve pin coupling and quincunx elastic coupling

　　1. The lack of elastic sleeve pin coupling
　　1) The material of the elastic sleeve pin coupling is cast iron, weighing 38.8kg, which makes the motor waste a lot of electric energy during the water supply operation, which affects the efficiency of the unit and increases the operating cost.
　　2) The elastic sleeve pin coupling is inconvenient to disassemble when repairing the water pump and the motor, and it is easy to deform and damage the cast iron coupling.
　　3) The elastic sleeve pin coupling has high requirements for the relative radial displacement of the two shafts, which is 0.2-0.6mm, which brings great difficulty in correcting the concentricity of the coupling.At the same time, due to the loosening of the screws during operation, the vibration and noise of the pump unit increase.
　　2. Advantages of plum-shaped elastic coupling
　　1) The selected material is cast steel. Under the condition of bearing the same torque, the volume and weight of the cast steel coupling are much smaller than that of cast iron.In the design, the weight of the coupling is reduced to 21 kg, which is 45.9% lighter than the elastic sleeve pin coupling, which lays a good foundation for energy saving of the water pump unit.
　　2) Because the plum blossom-shaped elastic coupling is sawed in the axial direction, the aperture becomes larger, and it forms a gap fit with the pump shaft. It is very convenient when repairing the pump unit and greatly reduces the labor intensity.
　　3) The relative radial displacement of the two shafts of the quincunx-shaped elastic coupling is 0.5~1.8mm, which can easily reach the standard when correcting the coaxiality of the coupling, which improves the maintenance efficiency.
　　4) New energy-saving typePlum blossom couplingThe cushion is made of new imported materials, which reduces the vibration of the pump from 0.48mm/s to 0.18mm/s, down 62.5%; the noise is also reduced, which improves the working environment of the workers.