OM4017.2 Maintenance - Section 4 Automatic Lube System Reciprocating Pump Page 4-19 INJECTOR OPERATION STAGE 1. The injector piston (2) is in its normal or "rest" position. The discharge chamber (3) is filled with lubricant from the previous cy- cle. Under the pressure of incoming lubri- cant (6), the slide valve (5) is about to open the passage (4) leading to the measuring chamber (1) above the injector piston (2). STAGE 2. When the slide valve (5) uncovers the pas- sage (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 admission of lubricant (6) to the passage (4) and meas- uring chamber (1). The injector piston (2) and slide valve (5) remain in this position until lubricant pressure in the supply line (6) is vented (relieved at the pump). STAGE 4. After venting, the injector spring expands, causing the slide valve (5) to move, so that the passage (4) and discharge chamber (3) are connected by a valve port (8).
Further expansion of the spring causes the piston to move upward, forcing the lubricant in the measuring chamber (1) through the pas- sage (4) and valve port (8) to refill the dis- charge chamber (3). Injector is now ready for the next cycle.