Groeneveld EG1703P03, Общее руководство

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Principle of operation 8
Dat
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a
ry 2011
Automatic Greasing System Twin-3
EG1703P03
2 Principle of operation
2.1 Introduction
In this chapter the principles of operation of the various parts of the Twin automatic greasing
system are discussed. The greasing cycle, pump unit, control unit, metering units, pressure switch,
signal lamp and Twin-3 display are discussed.
2.2 Greasing cycle
Every greasing cycle consists of four phases. The greasing cycles are performed alternately by the
grease lines-A and -B (see Figure 2.1). The 5/2-way valve, which is integrated in the pump housing,
determines which primary grease line is connected to the pump and which is connected to the
grease reservoir. The total greasing cycle has a predetermined time; the length of the four phases
depend on the circumstances. The different greasing cycles and phases are discussed below.
Figure 2.1 Overview of the various phases of the greasing cycle
2.2.1 Greasing cycle A
Pumping phase
The greasing cycle begins with a pumping phase. In this phase the grease is pumped from the
reservoir, through primary grease line-A, to the distribution blocks. The pumping phase ends when
the pressure at the pressure switch reaches a predetermined level. The time needed to reach that
predetermined pressure depends on various factors as temperature, grease consistency (thickness)
and the dimensions of the greasing system.
During the pumping phase, the metering units press a certain amount of grease (the dosage)
through the secondary grease lines to the grease points.
Cycle A Cycle B
pump
pressure
retaining
phase
pressure
decrease
phase
pause
phase pumping phase pressure
retaining
phase
pressure
decrease
phase
pause
phase
5/2 valve
pressure path
primary line-A
pressure path
primary line-B
pumping phase