UGSI Encore 700, Руководство по эксплуатации и обслуживанию

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CF.440.400.001.IM.0417
ENCORE
®
700 METERING PUMP
29
3.6 Theory of Operation
The theory of operation for the Encore® 700 Mechanical Diaphragm Metering
Pump is addressed by discussing the operation and interrelationships of the
following assemblies:
• Pump Drive Mechanism
• Speed Reducer
• Stroke Control Mechanism
• Liquid Ends (including head, valves, and connections)
The Encore® 700 metering pump is comprised of a liquid end and a pump drive
mechanism. The stroke length can be varied either manually or with an optional
electric stroke positioner. The pump is driven by an electric motor that can be
coupled either directly to the worm shaft (refer to Dwg. 440.400.001.010A)
or indirectly by a pulley drive arrangement (refer to Dwg. 440.400.001.020A).
The pulley drive arrangement provides a wide range of stroking speeds with
the same gear ratio and, therefore, a wide range of capacities. A double simplex
arrangement is also available (refer to Dwg. 440.400.000.020A).
3.6.1 Pump Drive Mechanism (Refer to Dwg. 440.400.000.010B)
The pump drive mechanism is contained within the gearbox. The motor rotates
the worm wheel through the worm shaft. Worm wheel is coupled to the variable
eccentric non-loss-motion mechanism, which rotates along with it, converting
the rotational motion into the reciprocating motion of the crosshead (27) through
a connecting rod (31). The crosshead provides a link between the connecting
rod and the liquid end. Stroke length of the pump can be changed from 0 to 100
% by turning the stroke control knob (47).
3.6.2 Speed Reducer (Refer to Dwgs. 440.400.000.010A)
The pump stroking speed is obtained through gear ratios, which provide 36
spm, 72 spm, and 144 spm. Each stroking speed is available in a pulley drive
confi guration or a direct drive confi guration. The four-step pulley combination
provides additional stroking speed with each gear ratio.
3.6.3 Stroke Control Mechanism (Refer to Dwg. 440.400.000.010B)
The stroke control mechanism consists of a round knob (47) secured to the
bearing carrier (22), which is bolted to the eccentric shaft (45) and turns on
threads through a double row bearing (19) inside the stroke control housing (25).
The stroke control housing has a linear scale showing 0 to 100%. This scale
indicates the percent stroke length of the pump. Combination of a linear scale
(0 to 100%) on the stroke control housing and a circular scale (0 to 10) provides
an accurate micrometer-type setting of the stroke, with a resolution of 0.25%.