Oil lubricated main drive shaft for fuel pump

摘要

A drive shaft (26) of a gear type fuel pump (2) forms a driving interconnection between an engine gearbox (4) and a shaft (14) which carries the driving gear (10) of the fuel pump. The drive shaft has a slightly diverging lubricant supply passage (65) which receives lubricant from an oil jet (70) in the engine gearbox and directs the lubricant to the engaged splines (44, 46) at the inboard end of the drive shaft. Lubricant from the area of spline engagement is returned to the gearbox via radial passage (78), annular lubricant return passage (68) and radial passage (80). O-ring seals (82, 84) on the drive shaft, which straddle a drain passage (86) prevent the mixing of the lubricant and the fuel which may envelop an intermediate portion of the drive shaft. Wear of the engaged, oil lubricated splines (40, 42) at the outboard end of the drive shaft should provide a general indication of spline wear at the inboard end of the drive shaft because both ends are exposed to similar lubrication.