THE GREASING SYSTEM

Evening Post, Volume CVI, Issue 112, 16 November 1928, Page 14

THE GREASING SYSTEM

TROUBLE WITH NIPPLES' Difficulty is sometimes experienced in persuading grease from a push-on grease gun to pass into the- bearing, which requires lubrication, owing to the greaso nipple being choked. In these cases, despite all effort and the application of considerable forco, tho greaso apparently, refuses to pass the nipple, giving the impression that ono is trying to pump grease against solid and unyielding resistance. s , The nipple as a rule is extremely simple in construction, consisting of a hexagon dome-headed ; screw, with a passage drilled, down its centre. This drilled passage is not of uniform diameter, but possesses two definite increases in size, the tiny hole visible in the centre of tho domed head communicating with a larger passage a short distanco within th© nipple, this in turn communicating with a still larger passage at the screwed end of the nipple. Within the latter passage is a small steol ball of a somowhat smaller diameter than tho bore of tho passage, which functions as a non-return valve, thus preventing grease which has been forced into the bearing from oozing out

of the nipple when tho grease gun is removed. Tho ball is provented from, falling out of tho largo passage- by throo projections produced by forcing tho conical inner end of tho nipplo inwards ' at throo points. \ Tho aperture around tho ball through which tho grease has to pass is very small, and it will bo appreciated that any particles of dirt which may find their way into tho nipplo will bo arrested at this point. Thero comes a time when sufficient foreign matter has accumulated completely to choke this minuto passage and" prevent the further passago of grease. Bomoval of tho nipplo will reveal tho steel ball firmly held against theretaining projections, and if it is forced into the nipple with the help of a pieceof stiff wire, or a small nail, the obstructing matter will b© dislodged and tho nipplo will again function correctly whon replaced. A more satisfactory cure will bo effected if the nipplo is thoroughly washed in petrol beforo boing replaced, thus ensuring eomploto removal of any obstructive matter. ' The fact that grease will not go into tho bearing does not, however, always mean that the nipple is at fault. The oilway itself may have become clogged with hard grease. In this case it is necessary to take tho bearing down and clean out the groove.