Development And Research Of The Intellectual Whole-Machine Balancing Instrument For Dual Rotor System With Little Rotating Speed Difference

Unbalanced vibration signal of double-shaft rotating system with little rotating-speed difference is a composite signal called "beat", How to separate two rotors' unbalanced weight from "beat" is the key of balancing for this rotating system. On the basis of studying the whole machine balancing principle and method for dual-rotor systems with little rotating speed difference, this paper discuss the design of the intellectual balancing instrument in detail from the hardware and software, then we conducted the instrument on a horizontal decanter centrifuge ,WL-350,in the laboratory and gained a satisfactoiy result. Some important and creative conclusions are achieved from study as follow:1.Through a lot of experiments, we find out the effect between two rotors' unbalanced vibrations is weak, so we can get four inner rotor's amplitude value from left and right bearings by trial-weight twice, and get four external rotor's amplitude value from left and right bearings by trial-weight twice. It is said that when get eight amplitude value and effect coefficient by trial-weight four times, we can deal with whole machine balancing for dual-rotor system with little rotating speed difference. The eight effect coefficient method can get high balancing precision and simplify the balancing of this rotor system, so it has great application prospect.2.Firstly this paper introduce the whole machine balancing principle and method for dual-rotor systems with little rotating speed difference firstly, then discuss key points such as picking up base signal , picking up "pai" signal ,measuring rotor speed, capturing the value of wave crest and through, calculating the phase values of unbalanced weight ,processing odd phases and finding each rotor's amplitude. On the foundation of above theories, using signal process technique and chip microprocessors technique, we developed a portable intellectual instrument, the first domestic device .which can balance dual-rotor system with little rotating speed difference quickly and accurately. It is also characterized with its stability ,low cost and simple operation. we conducted the instrument on two-rotor system and gained a satisfactory result.3.Put forward and test the method of balancing two rotors of the horizontal decanter centrifuge simultaneously. In this method, to balance inner and external rotors at the sameIItime, the machine only need be started three times(one for measure the rotors' original vibration, the other for measure the rotors' vibration after inner and external rotor with left-trial-weight simultaneously, another for measure the rotors' vibration after inner and external rotor with right- trial-weight.) .However, if balance rotor individually, we should start the machine six times. This method can decrease the times of starting machine and improve work efficiency, so it has great application prospect.4.In accordance with the difficult problem of trial-weight on the using horizontal decanter centrifuges, this paper bring forward a method to gain the inner unbalanced weight through adding trial-weight on the external rotor. We have discussed the theory of this method in detail and the feasibility of this method have been accepted by the high-grade technician in some factory.