Optimization of Factors Affecting Vibration Characteristics of Unbalance Response for Machine Motorized Spindle Using Response Surface Method

Table 1

The definition of design factors, their lower and upper limits, and the FEM nominal level.

Definition	Design factors	Lower Level	Nominal Level	Upper Level
The inner diameter of spindle shaft at the back bearings location.	Y1 [mm]	40	45	55
The inner diameter of spindle shaft at the motor-rotor location.	Y2 [mm]	40	45	60
The inner diameter of spindle shaft at the front bearings location.	Y3 [mm]	50	54	60
The locations of back bearings set to the back end of the motor rotor.	Y4 [mm]	10	50	70
The locations of first front bearings set to the front end of the motor rotor.	Y5 [mm]	20	50	60
The locations of second front bearings set to the front end of the motor rotor	Y6 [mm]	10	50	60
Cutting Force	Y7 [N]	3330	3700	4000
Rotating Unbalance mass	Y8 [kg]	0	6	10