Measuring and control method of deformation process of generator´s retaining rings on hydraulic bulging strengthening technology based on virtual instrument

The hydraulic bulging strengthening technology is a kind of strengthening technology of large generator´s retaining ring. The ring billet is deformed uniformly by the super pressure water while the punch working angle is 60° and the pressure between the punch and the rings is 1MN. In the deformation process the thickness of the ring must be controlled accurately. Using ultrasound sensors which the accuracy can achieve 0.1mm to measure real-time thickness of the ring billet can greatly improve the accuracy. Controlling the pressure of the oil-hydraulic machine and ultra-high pressure pump with virtual instrument may improve productivity. The experiment in 5MN oil-hydraulic machine proves that the external generatrices of the ring billet are nearly line after the thickness deformations of the top, middle and bottom of the ring billet are 1.49mm, 1.69mm and 1.65mm. The ring billet is 1/5 of 300MW18-18 steel retaining ring.