 Gerotor Pumps |
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Gerotor Pump
Overview
Gerotor pumps are
internal gear pumps without the
crescent. The rotor is the internal (drive) gear shown below in gray, and
the idler is the external (driven) gear, shown below in orange. They are
primarily suitable for clean, low pressure applications such as lubrication
systems or hot oil filtration systems, but can also be found in low to
moderate pressure hydraulic applications.
How Gerotor Pumps Work
1. Liquid enters the suction port
between the rotor (gray gear) and idler (orange gear) teeth.
2. Liquid travels through the pump between the teeth of the
"gear-within-a-gear" principle. The close tolerance between the
gears acts
as a seal between the suction and discharge ports.
3. Rotor and idler teeth mesh completely to form a seal equidistant from the discharge
and suction ports. This seal forces the liquid out of the discharge port.
Advantages
- High Speed
- Only two moving parts
- Only one stuffing box
- Constant and even discharge
regardless of pressure conditions
- Operates well in either direction
- Quiet operation
- Can be made to operate with one
direction of flow with either rotation
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Disadvantages
- Medium pressure limitations
- Fixed clearances
- No solids allowed
- One bearing runs in the product
pumped
- Overhung load on shaft bearing
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Applications
Common gerotor pump applications
include, but are not limited to:
- Light fuel oils
- Lube oil
- Cooking oils
- Hydraulic fluid
Materials Of
Construction / Configuration Options
- Externals (head, casing) - Cast iron
- Internals (rotor, idler) -
Steel
- Bushing - Carbon graphite,
bronze, and other materials as needed
- Shaft Seal - Lip seals, component mechanical seals
- Packing - Not commonly used for
gerotor pumps
Manufacturers
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