![background image](http://html1.mh-extra.com/html/gardner-denver/apex25-30a/apex25-30a_operating-and-service-manual_3576437009.webp)
13-25-608 Page
8
SECTION 1
GENERAL INFORMATION
Figure 1-1 - COMPRESSOR CYCLE
COMPRESSOR
- The rotary screw compressor is a single stage, positive displacement rotary machine
using meshing helical rotors to effect compression. Both rotors are supported between high capacity anti-
friction bearings located outside the compression chamber. Roller bearings are used at the inlet end of
the rotors to carry part of the radial loads. Angular contact ball and roller bearings at the discharge end
locate each rotor axially and carry all thrust loads and the remainder of the radial loads.
COMPRESSION PRINCIPLE (
Figure 1-1
)
- Compression is accomplished by the main and secondary
rotors synchronously meshing in a one-piece cylinder. The main rotor has four (5) helical lobes 72
°
apart.
The secondary rotor has five (6) matching helical grooves 60
°
apart to allow meshing with main rotor
lobes.
The air inlet port is located on top of the compressor cylinder near the drive shaft end. The discharge port
is near the bottom at the opposite end of the compressor cylinder.
Figure 1-1
is an inverted view to show
inlet and discharge ports
. The compression cycle begins as the rotors unmesh at the inlet port and air is
drawn into the cavity between the main rotor lobes and the secondary rotor grooves (A). When the rotors
pass the inlet port cutoff, air is trapped in the interlobe cavity and flows axially with the meshing rotors (B).
As meshing continues, more of the main rotor lobe enters the secondary rotor grove, normal volume is
reduced and pressure increases.
Oil is injected into the cylinder to remove the heat of compression and seal internal clearances. Volume
reduction and pressure increase continues until the air/oil mixture trapped in the interlobe cavity by the
rotors passes the discharge port and is released to the oil reservoir (C). Each rotor cavity follows the
same
“fill-compress-discharge” cycle in rapid succession to produce a discharge air flow that is
continuous, smooth and shock free.
Summary of Contents for APEX25-30A
Page 11: ...13 25 608 Page 10 Figure 1 2 COMPRESSOR ILLUSTRATION VARIABLE SPEED 304USC797 A Ref Drawing...
Page 12: ...13 25 608 Page 11 Figure 1 3 COMPRESSOR ILLUSTRATION FIXED SPEED 305USC797 A Ref Drawing...
Page 27: ...13 25 608 Page 26 Figure 4 2 WIRING DIAGRAM VS 230 VOLT 306USC546 01 Ref Drawing Page 1 of 4...
Page 28: ...13 25 608 Page 27 Figure 4 3 WIRING DIAGRAM VS 230 VOLT 306USC546 01 Ref Drawing Page 2 of 4...
Page 29: ...13 25 608 Page 28 Figure 4 3 WIRING DIAGRAM VS 230 VOLT 306USC546 01 Ref Drawing Page 3 of 4...
Page 30: ...13 25 608 Page 29 Figure 4 3 WIRING DIAGRAM VS 230 VOLT 306USC546 01 Ref Drawing Page 4 of 4...
Page 31: ...13 25 608 Page 30 Figure 4 3 WIRING DIAGRAM VS 575 VOLT 307USC546 02 Ref Drawing Page 1 of 4...
Page 32: ...13 25 608 Page 31 Figure 4 4 WIRING DIAGRAM VS 575 VOLT 307USC546 02 Ref Drawing Page 2 of 4...
Page 33: ...13 25 608 Page 32 Figure 4 4 WIRING DIAGRAM VS 575 VOLT 307USC546 02 Ref Drawing Page 3 of 4...
Page 34: ...13 25 608 Page 33 Figure 4 4 WIRING DIAGRAM VS 575 VOLT 307USC546 02 Ref Drawing Page 4 of 4...
Page 45: ...13 25 608 Page 44 Figure 4 7 WIRING DIAGRAM FS 575 VOLT 309USC546 01 Ref Drawing Page 1 of 3...
Page 46: ...13 25 608 Page 45 Figure 4 8 WIRING DIAGRAM FS 575 VOLT 309USC546 01 Ref Drawing Page 2 of 3...
Page 47: ...13 25 608 Page 46 Figure 4 8 WIRING DIAGRAM FS 575 VOLT 309USC546 01 Ref Drawing Page 3 of 3...
Page 51: ...13 25 608 Page 50 Figure 4 8 PIPING AND INSTRUMENTATION ILLUSTRATIONJ 301USC797 C Ref Drawing...