490 



REPORT — 1886. 



of experiments on oil-bath bearings, conducted for the Institution of 

 Mechanical Bngineerv'^. 



Figs. 8 and 9 show the form of bearing used for the guide-wheels on 

 the machine, fig. 3. They were adopted as the beat of a number which 

 were tried for the purpose. A fixed spindle (a) is secured to the frame 

 (k) by the bolts (d). On (a) is a fixed collar (6), with a projecting rim 

 (e e), and also a loose collar screwing on it with a similar rim (e e). These 



Fig. 8. 



Fig. 9. 



rings fit into recesses turned in the wheel {h Ji) ; the bottoms of the 

 recesses are packed with leather rings (//). It is obvious that on 

 screwing up the collar (c), the rims on both sides of the wheel are forced 

 into the leather, thus making a running joint, the oil having to escape 

 past the leather before it can get out. 



This device answers fairly well, for the wheel (g) being hollow and 

 filled with oil, perfect lubrication is ensured, although in this case also 

 a slight amount of oil escapes. 



Some experiments just made show that even the best of leathers are 

 very porous and spongy, absorbing oil very readily, and when employed 

 as a packing for bearings this material seems to act as a pumping appa- 

 ratus, continually sending oil in the wrong direction. Leather is not 

 therefore a safe material for packing a running joint against oil ; and in 

 spite of numerous tests, so far, no really suitable material has been 

 found. 



Fig. 10 shows the arrangement of bearing adopted for the guide and 

 pressure wheels on the machine at the Inventions Exhibition, 1885, 

 and also on that shown in figs. 1 and 2. A steel spindle is keyed to the 

 wheel b, and runs in bearings bored in the phosphor bronze, or cast-iron 

 frame (/). Caps (c c) are screwed on (/), thus forcing the semi-lubricant 

 which fills (c) and (d) into the beai-ing. Rings of packing (e e), made 

 of strips of leather and cotton wick, are sufficient to prevent the escape 

 of the lubricant at the running joint. These bearings run for months 

 without requiring attention. 



