Flowserve Gearex Rotary Gear Pumps External and Internal Bearing - Manual (Page 11)

EXTERNAL GEAREX USER INSTRUCTIONS ENGLISH 71569246 (2167B-E1)
Page 11 of 36
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2.5 Recycling and end of product life
At the end of the service life of the product or its parts,
the relevant materials and parts should be recycled or
disposed of using an environmentally acceptable
method and in accordance with local regulations. If the
product contains substances that are harmful to the
environment, these should be removed and disposed of
in accordance with current local regulations. This also
includes the liquids and/or gases that may be used in
the "seal system" or other utilities.
Make sure that hazardous substances are
disposed of safely and that the correct personal
protective equipment is used. The safety specifications
must be in accordance with the current local
regulations at all times.
3 PUMP DESCRIPTION
3.1 Configurations
Flowserve "GEAREX" Pumps are single stage,
positive displacement pumps especially designed for
the petroleum industry in the transfer of oils and other
liquids of varying viscosities. The flow of liquid through
the pump is accomplished by the progressive
movement of sealed cavities formed by the space
between the pumping rotors (gear) teeth and the bores
of the pump body. Recirculation of the liquid (slip) is
prevented by the intermeshing of the paired pumping
rotors and the maintaining of precise diametral and
axial clearances between the pumping rotors and pump
body. To eliminate hydraulic thrust, the pumping rotors
are of double helical design.
The key assembly of the Gearex pump is the rotating
element. Each rotating element consists of a drive
shaft and a driven shaft running on parallel axes at a
fixed center distance. Each shaft holds bearings, one
timing gear and one pumping rotor, plus the assorted
hardware (locknuts, spacers) required for mounting.
The timing gears maintain the clearance between the
drive and driven pumping rotors, eliminate contact
between the rotors and turn the driven shaft. Heavy
duty roller bearings eliminate radial contact between
the pumping rotors and the body bores and support the
loading on the shafts produced by the pumping action.
Fixed bearings at one end position the shafts axially
and prevent contact between the ends of the pumping
rotors and the bearing housings. Lubrication of the
bearings is provided by the oil contained in the
housings (sumps).
The bearing configuration provides a rear pull-out
feature which permits the quick removal of the entire
rotating element without disturbing the pump body or
the driver. The use of a spacer type coupling between
the pump and driver is necessary to apply this feature.
Standard shaft sealing is provided by packing which is
factory installed with the gland requiring only minor
adjustment prior to pump start-up. Mechanical seals
are optional equipment and when provided require no
adjustment prior to or during pump operation.
All pumps are shop performance tested to ensure
mechanical reliability and compliance with the specified
conditions of service. They are carefully inspected and
prepared for shipment. All exterior machined surfaces
are coated with rust preventative and all openings are
provided with covers or plugs.
3.2 Name structure
The pump size will be engraved on the nameplate. The
following example explains how the pump name
identifies the construction features and options.
D-2
The letter indicates the “nominal pump size” and the
digit is the sub category of size. In this case the D-2
size pump is the larger of the two D size pumps. The
pump sizes range from B-1 to E-6 with several different
casing sizes available in each basic pump size and
different rotor widths available in each size.
3.3 Design of major parts
3.3.1 Pump casing
The pump casing is a casting with side suction and side
discharge connections. It is a one piece pressure
retaining casting with gasket connections to the seal
housings and the suction and discharge flanges.
3.3.2 Pumping Gears
The pumping gears are double helical intermeshing
gears, mounted to the drive and driven shafts to create
a positive displacement pumping action inside the
pump body.
3.3.3 Shaft
The drive shaft is mounted on bearings with the
pumping gear and timing gear mounted to the shaft. It
has a keyed drive end. The driven shaft is also
mounted on bearings with the pumping gear and timing
gear mounted to the shaft.