tailieunhanh - Alignment of vertical shaft hydrounits - part 3

Phần kết quả của các chương trình máy tính cung cấp ra tổng plumb dữ liệu cho trung tâm của runout trong mils mỗi inch. Ngoài ra còn có một out-of-tròn tự động kiểm tra để kiểm tra tính chính xác của các bài đọc. Các đơn vị với các vòng bi tự cân bằng không có thể sử dụng hệ thống Permaplumb bởi vì nó không phải là có thể có được một kiểm tra runout tĩnh. | The results portion of the computer program provides the total out of plumb data for the center of runout in mils per inch. There is also an automatic out-of-roundness check to check for accuracy of the readings. Units with self equalizing bearings cannot use the Permaplumb system because it is not possible to obtain a static runout check. With the Permaplumb system it is difficult to accurately determine dogleg in the shaft and there is no way at all to check for offset at the coupling. Limited wire or Hamar laser readings may be used to check for shaft straightness but if the static runout diameter is acceptable at all of the guide bearing journals the straightness of the shaft should not be critical. 5. BASICMEASUREMENTS The position of the generator and turbine shafts relative to plumb and the stationary components need to be determined. Also the straightness of the shafts and the perpendicularity of the thrust runner to the shaft has to be addressed. Preliminary Checks for All Units a. Use a precision machinist level to level the upper bridge the lower bridge on umbrella units. Check for any soft feet condition on any of the bridge legs. A soft foot condition is similar to short leg on a four legged table and if left uncorrected can cause distortion of the bridge. Check for a soft foot by first checking that all bridge leg bolts are securely tightened. With a dial indicator check the rise of each leg as its mounting bolts are loosened. Retighten the mounting bolts after the rise is recorded so that only one leg is loose at a time. If one leg rises more than the other legs it is a soft foot and shims should be placed under that leg to correct the condition. For example if one leg of a six leg bridge rises inch while the other five only rise inch a inch shim should be added to the soft foot. There may be more than one soft foot. Shims should be added accordingly so that the rise of each leg is nearly the same. b. Allow the thrust block to .