Study on Optimization of Pump Shaft Transmission System of Plastic Centrifugal Pump

Table 10

Moment of inertia and β of each section of the pump shaft.

Segment label	Diameter of axle (mm)	Moment of inertia (mm^4)	I i/I	β i
I	25	19174.76	1
II	20	7853.982
III	40	125663.7
VI	45	201289
V	49	282979
VI	45	201288.96
VII	40	125663.7
VIII	38	102353.9

According to the different diameters, the shaft is divided into n sections, then the inertia moments of each section are I1, I2, I3 …Ii…In. I is moment of inertia of pump shaft. Using the step function in the singular function, the reciprocal of the inertia moments of the step shaft of N sections can be expressed as formula (12). β is one of the sub-formulas, which has no specific meaning.