Section 4 - Maintenance OM4033.2 4-18 Automatic Lubrication System INJECTOR OPERATION The injector piston (2) is in its normal or “rest” position. The discharge chamber (3) is filled with lubricant from the previ- ous cycle. Under the pressure of incom- ing lubricant (6), the slide valve (5) is about to open the passage (4) leading to the measuring chamber (1) above the injector piston (2). STAGE 1. STAGE 2. When the slide valve (5) uncovers the passage (4), lubricant (6) is admitted to the measuring chamber (1) above the injector piston (2) which forces lubricant from the discharge chamber (3) through the outlet port (7) to the bearing. STAGE 3.
As the injector piston (2) completes its stroke, it pushes the slide valve (5) past the passage (4), cutting off further ad- mission of lubricant (6) to the passage (4) and measuring chamber (1). The injector piston (2) and slide valve (5) remain in this position until lubricant pressure in the supply line (6) is vented. STAGE 4. After venting, the injector spring ex- pands, causing the slide valve (5) to move, so that the passage (4) and dis- charge chamber (3) are connected by a valve port (8).
Further expansion of the spring causes the piston to move up- ward, forcing the lubricant in the mea- suring chamber (1) through the passage (4) and valve port (8) to refill the discharge chamber (3). Injector is now ready for the next cycle.