- 19 -
EN
951-180-074-EN Version
03, last updated
2019 / 07
3
3. Overview
, functional description
SKF CircOil centralized lubrication system, Fig. 3
3.5 Operation of the gerotor pump units
)
See Figure 4
SKF gerotor pump units of product series 143 have a constant dis-
placement volume and one delivery circuit.
The annular-toothed feeding element, also referred to as the gero-
tor, is equipped with a cycloid contour, which creates a large
tooth meshing length. This yields a low volumetric flow pulsation
and thus very smooth running, low noise production, and good suc-
tion characteristics.
SKF gerotor pumps consist primarily of pump housing (
1
), the shaft
(
2
), the displacement elements toothed rotor (
3
) and annular gear
(
4
), and the lid (
5
).
They are driven by attached AC motors of frame sizes 71 to 132 with
flameproof enclosures.
The motors are designed for a rated motor voltage of 230/400
V or
400/690 V for 50 Hz networks
with mains voltage fluctuations of
up to ± 10% and frequency fluctuations from -5% to +3% accord-
ing to EN ISO 60034-1.
The normal coils used for this purpose in motors are tailor-
made and meet the IE3 efficiency level according to EU Directive
2009/125/EC.
Special voltage versions with special coils for 50 Hz and 60 Hz net-
works are available for order.
Suction and displacement process
See Figure 4
The shaft drives the centrally mounted toothed rotor in the indicated
direction of rotation via a feather key. The toothed rotor meshes
with the outer, eccentrically mounted annular gear and rotates with
it. The openings between teeth arising in the suction area (
S
) draw
the pumped medium in. The suction and pressure area is separated
from the tooth meshing area (
Z
) by a radial gap (
R
) formed by the
tooth profiles of the annular gear and the toothed rotor as they slide
onto one another. In the pressurized area (
P
), the fluid is fed to the
pressure port through increasingly small chambers.
1
5
4
3
P
S
2
Z
P
R
S
P
S
Gerotor pump units, Fig. 5
Foot design
Functional description of a gerotor pump, Fig. 4