01. Bearing maintenance and disassembly procedures
① Remove the instrument probe and other instrument wiring that hinders bearing removal.
② Remove the facet bolts and positioning pins in the bearing cover, gently lift the bearing cover with a jackscrew, and then lift off the bearing cover.
③ Disassemble the facet bolts in the bearing body and remove the upper part of the radial bearing.
④ Use a special tool for picking up the shaft to gently lift the shaft to a height that allows the half-bearing body to rotate around the shaft, and shall not exceed 0.15mm. Turn the lower bearing body around the axis to the upper part of the journal, and remove the lower bearing.
Note: Do not lift the rotor at both ends of the rotor at the same time, nor use a crane to lift the rotor without removing the cover. Bearings with heat-sensitive elements must not damage instrument wires during flipping.
⑤ Record the position and direction of each tile in the bearing shell, loosen and remove the positioning screws on the back of the tile, and take out each tile in turn.
02. Main points for maintenance of tilting tiles
① The babbitt alloy layer of the tiles should be free of defects such as cracks, falling pieces, detachment, burning, rolling, wear and nap. Axial scratches and grooves are not allowed on the surface of babbitt alloy, and the depth of circumferential scratches and grooves should not exceed 0.10mm. After the tiles are colored or dipped in kerosene and inspected, the Babbitt alloy should fit well, there should be no eccentric wear on the surface, and the contact marks should be uniform along the axial direction.
② The load-bearing surface of the back of the tile is smooth, and the contact marks with the tile shell are uniform along the axial direction and maintain linear contact. The force-bearing surface of the tile swinging around the pivot is evenly contacted, and the cooperation with the pivot pin is not loose. There are no burning indentations or heavy load marks on the back of the tile.
③The oil inlet edge of the tiles has a smooth transition, which is suitable for oil flow to enter the oil wedge.
④ The thickness of tiles in the same group should be uniform, and the thickness difference between each other should be measured with a dummy shaft or journal, and should not be greater than 0.01mm.
⑥The pin holes and corresponding pins on the back of the tiles should have no wear or eccentric wear. The diameter gap of the positioning pin in the pin hole should not be less than 2.0mm. After assembly, the top gap between the pin and the pin hole should not be less than 1.5mm. The tiles swing flexibly in the tile shell and do not push against the tiles.
⑥ For tiles with heat-sensitive elements, the heat-sensitive element and the tiles are reliably fixed and not loose, and the lead insulation protection layer is good. After assembly, the thermal components and leads do not prevent the tiles from swinging flexibly in the tile shell, nor do they affect the entire bearing assembly.
⑦The contact line on the back of the tile passes through the geometric center of the back of the tile, and the shapes on both sides of the contact line are symmetrical. When swinging around the contact line, any part of the surface of the tile shell should not be lower than the oil seals on both sides.
⑧When the shaft is pressed on the lower half of the supporting tiles, the left and right tiles should be evenly loaded.
03. Key points for bearing shell maintenance
① The middle facets of the tile shell are tightly fitted, and the positioning pins are closely matched. After tightening the middle facet bolts, the middle facets of the tile shell are well aligned.
②The oil seals on both sides of the bearing shell are not worn and the clearance is not out of tolerance. The joint surfaces of the upper and lower middle parts of the oil seal are tight and do not top the tile shell. The floating oil seal floats flexibly and has a good end face.
③ Use red lead to check the contact of the tile shell in the lower half bearing seat. The contact should be good. The left and right sides are flush with the middle plane of the bearing seat, and the gap on both sides is even, front and rear, left and right, and not larger than 0.05mm.
The anti-rotation pin of the tile shell is not higher than the center plane of the bearing seat. After tightening the middle face bolts, the middle facets of the tile shell and the bearing seat are tightly connected without any gaps.
④The tightness or clearance on the back of the bearing shell meets the manufacturer's design requirements.
⑤The oil inlet and oil return holes of the tile shell are aligned with the corresponding oil holes of the bearing seat, and the vibration measurement probe hole, temperature measurement hole, etc. can be aligned. The flow-limiting screw of the oil inlet hole of the tile shell is not loose and is fixed reliably, and the aperture meets the design requirements. The oil inlet and return holes are not blocked.
Source: Basic knowledge of benchwork
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