Research on key technologies of bearing preload of spindle based on piezoelectric actuators

Abstract

This study analysed the influence of bearing preload on the stiffness of spindle bearings. MATLAB/Simulink is used to calculate the vibration of simplified spindle system. The vibration of the simplified spindle system decreases with the increase of bearing preload. A kind of force output characteristics of piezoelectric actuators test device was designed. Experimental analysis of the maximum force output characteristic, hysteresis characteristic, creep characteristic and stability characteristic of PSt 150/4/7 VS9-type piezoelectric actuators under different initial loads, voltage frequencies, cycles working and voltage travel. The evaluating indexes are the maximum output force, average hysteresis, maximum deviation, drift amount and cycle delay. In conclusion that the piezoelectric actuator has better repeatability and stability under the initial load is around 150 N and low-voltage frequency. It is not suitable for multiple cycles working. The increment of output force is proportional to starting voltage at same voltage travel. MATLAB/Simulink is used to calculate the feasibility of variable bearing preload strategy based on a piezoelectric actuator. It provided scientific references for the research of high performance and intelligent spindle.

Keywords

• hysteresis
• machine bearings
• piezoelectric actuators
• machine tool spindles
• vibrations
• creep
• piezoelectric actuator
• spindle bearings
• simplified spindle system
• force output characteristics
• piezoelectric actuators test device
• maximum force output characteristic
• hysteresis characteristic
• stability characteristic
• different initial loads
• voltage frequencies
• voltage travel
• maximum output force
• maximum deviation
• drift amount
• cycle delay
• initial load
• low-voltage frequency
• starting voltage
• variable bearing preload strategy
• intelligent spindle