Graco 309015B, Руководство по конструкции

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23 309015
System Operation (cont.)
Basic Injector Operation
Refer to Fig. 3.
Stage 1
At stage 1, the injector’s discharge chamber contains lubricant from the preceding cycle. This lubricant is not under
pressure, and the piston is at rest.
As the next cycle begins, pressurized lubricant enters the injector and starts to open the slide valve, which com-
presses the injector spring.
Stage 2
Pressurized lubricant pushes the slide valve upward, opening a path which allows the lubricant to flow into the mea-
suring chamber above the piston. This pressure forces the piston down, pushing the lubricant from the discharge
chamber, through the outlet, to the bearing.
Stage 3
At the bottom of its stroke, the piston pushes the slide valve downward, closing off the path to the measuring cham-
ber. The piston and slide valve hold this position as long as the inlet lubricant remains under pressure.
Stage 4
As the lubricant inlet pressure is relieved, the slide valve moves down and the injector spring expands. The slide
valve opens a port between the lubricant path and the discharge chamber.
As the spring continues to expand, it forces the piston upward, which pushes the lubricant out of the measuring
chamber, back down the path, through the slide valve port, and into the discharge chamber.
Fig. 3
9640A