Dynamic Analysis and Design of a Balancer for a Three-Column Centrifuge

Table 1

Parameter setup.

Parameters	Note	Nominal value	Unit
Mass of the core assembly excluding the motor		62	kg
Mass of the motor		18	kg
Distance between axes of the motor and the core assembly		0.36	m
Mass of the unbalance		2	kg
Height of the unbalance relative to the suspension plane		0.1	m
Gyration radius of the unbalance		0.1	m
Stiffness of the suspension rods			N m^−1
Stiffness of the compression springs		8000	N m^−1
Pretightening force of the compression springs		100	N
Distance between two supporting legs		0.468	m
Initial length of the rods		0.1	m
Axial frictional damping force of the rods		10	N
Coefficient of friction in the spherical joints		0.1	—
Radius of the spherical joints		0.02	m
Gyration radius of the balancer		0.13	m
Installing height of the balancer relative to the suspension plane		0.2	m
Mass of each ball in the balancer		1	kg
Viscous damping coefficient in the balancer		0.05	N m s rad^−1
Transmission ratio between the motor and the bowl		1	—