Thread Content
1. When a crankshaft is used, the connecting rod usually adopts a closed structure. First, check the contact surfaces between the tile back and the connecting rod, as well as between the inclined tile seat and the inclined shackle; also check the contact surface between the inclined shackle and the connecting rod. If the contact is poor, grinding and scraping are required to ensure uniform contact across all contact surfaces ； Checked with red lead oil; the contact area exceeds 60%. When grinding off the old tiles, adjust the shims according to the shaft bearing clearance and shim thickness measured before repairs, so that the shaft bearing is about 0.05 mm smaller than the shaft journal. Apply red lead oil to the shaft, install the connecting rod on the crank pin, tighten the shims, and use a feeler gauge to check for any gaps in the big end bearing and the shims. Check the small shaft and journal bearings in the same way. If there is a gap between the wafer and the shim, the gasket must be adjusted separately or the shim must be scraped to eliminate it. After assembling the connecting rod, turn the shaft and grind the bearing shells ； If grinding is not performed, skewing is likely to occur. Remove the connecting rod, scrape it according to the degree of contact, and grind it repeatedly; adjust the shaft counter-gasket as needed to ensure that the gasket remains compressed at all times with no gaps in the bearing shells. When the contact between the bearing shells and the crank pins is even, with each arc surface of contact between the crank pins and a bearing shell forming 120 degrees, the contact points do not overlap, and the contact area exceeds 70%, the gap can be adjusted by using shims. After the new bearing ring is fitted with the inner diameter, the back of the ring is filed, and then it is lapped against the shaft journal. 2. When a crankshaft is used, a split structure is adopted, with the large-end cover and the shaft body being connected by bolts. The grinding of the connecting rod big end bearing is carried out on the crank pin. The concave surfaces of the tile back and the large end of the connecting rod should be carefully filed, and no shims should be used on the tile back. The gasket at the joint should be flat; it is not allowed to use offset gaskets. The gap between the inner side of the gasket and the surface of the journal should not be too large; it is generally 0.10–0.25 mm. Otherwise, a large amount of lubricant from the bearing will leak out, resulting in poor lubrication of the bearing. The method of repairing large-tile roofs depends on the degree of damage. The steel roof shell and bearing alloy should bond well, with no cracks, pores, delamination, or similar defects. When the thickness of the worn bearing alloy is less than 2/3 of its original thickness, it should be replaced (for thick-walled bearings). For the large and small end bearings of the connecting rod, they should be lapped separately first, and then the connecting rod should be assembled; the shaft bearings should also be lapped by turning the shaft ； After that, the connecting rod is removed, and scraping is carried out depending on the degree of contact; this process is repeated until the contact area reaches over 70% and the contact is even.