PROJECTS IN FARM MACHINERY REPAIR 323 



291. Babbitting a Split-Box Bearing. Place the shaft 

 in the lower part of the box which forms the bearing and 

 block it in position. Place liners on the box to touch the 

 shaft the full length, first cutting two or three notches on the 

 liner next to the shaft thru which the babbitt can run from 

 the upper half of the box to the lower. Bolt the top part of 

 the box in position, stop the ends and pour the babbitt. When 

 the babbitt is set, drive a cold chisel between the boxes to 

 break the babbitt formed in the notches of the liner, bevel 

 the edges of the babbitt next to the shaft, and cut oil grooves 

 in the babbitt of each half of the box with a diamond point or 

 round nose chisel. These grooves should cross on the oil hole 

 and run to the ends of the box to form carriers for oil. 



A split box may also be babbitted by pouring the babbitt 

 on the shaft when placed in the lower half of the box only. 

 When the babbitt reaches the level of the top of the half box, 

 place the liners in position, then the upper half of the box, and 

 pour it full. 



292. Scraping a Babbitted Bearing. With the split 

 bearing, it is nearly always necessary to fit the bearing to the 

 shaft by scraping. This is done by coating the surface of the 

 shaft with lampblack and oil, or Prussian blue, and adjust- 

 ing it in the bearing; then revolve the shaft. Open the 

 bearing and note if it formed a good contact with the shaft; 

 if it only touched the shaft at spots, scraping is necessary. 

 Scrape the high places in bearing with regular bearing scra- 

 pers or with a triangular file that has been ground for this pur- 

 pose, until practically the entire surface of bearing is in con- 

 tact with shaft. 



