The invention provides an ultrasonic
cutting electric spindle driven by a hollow
servo motor. The ultrasonic
cutting electric spindle comprises an electric spindle body and an acoustic
assembly, wherein the electric spindle body comprises a hollow main shaft, a shaft sleeve, a shell, a motor mounting plate and a hollow
servo motor; the hollow main shaft is installed in the shaft sleeve through bearings, the shaft sleeve is coaxially installed at the lower end of the shell, the motor mounting plate is arranged at the upper end of the shell, and the hollow
servo motor is installed on the motor mounting plate; and the acoustic
assembly is coaxially installed in the hollow main shaft through a conical
flange. According to the ultrasonic
cutting electric spindle, the hollow shaft servo motor isused for driving, the hollow shaft is driven to rotate through an expansion sleeve and a hollow shaft so as to drive the acoustic
assembly to realize ultrasonic cutting, a transmission chain is short, so that the rotating motion precision of the main shaft is improved, and therefore
machining precision is improved; and meanwhile, a mercury conductive
slip ring is used for conducting
electricity,compared with a traditional ultrasonic cutting electric spindle utilizing the carbon
brush to transmit electric signals, the space
layout is more compact, and electric transmission is more reliable.