Howden Roots RAS Whispair, Инструкция по установке, эксплуатации и обслуживанию

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ILRB-3000 GEA20261
RAS and RAS-J WHISPAIR Blowers
Page 11 of 33
Lubrication
Separate Opposite Gear End Reservoirs
Roots blowers use a simple and reliable splash lubrication
system. All friction parts -- gears, bearings, and shaft seals
− are lubricated by dipping them directly into oil reservoirs
or by splash oil from other rotating parts. All reservoirs
require the same grade of oil as specified in Table 3 for
various ambient temperature ranges at the installation site.
Reference the appropriate assembly drawing in Figure 15
to better understand the following discussion.
At the opposite gear end of the blower, the upper (or
driven) shaft bearing is lubricated from its own oil reservoir,
formed by the bearing carrier (6) and the deep blind end
cover (5A).
At a normal oil level, bearing rollers dip into the oil as they
roll through the bottom of their raceway. The oil picked up
is carried over the top by bearing rotation, and some of it
transfers to the shaft behind the bearing to lubricate the
dynamic lip-type inboard seal (27). A slight amount of oil
may work through this seal, but it will be thrown off by the
shaft slinger, and it will be further prevented from reaching
the air chamber by a labyrinth-type seal where the shaft
passes through the headpiece. The chamber between the
two sealing points is vented to atmosphere and serves not
only to drain any seal leakage but also to keep the
lubrication system at atmospheric pressure.
At the lower (driving) shaft, the arrangement is the same as
described above when a short shaft for direct coupling is
provided. An outboard shaft seal (23) is provided in the end
cover (5). On V-belt driven blowers, the drive shaft and
bearing carrier (63) are extended and provided with an
additional inboard bearing (60). This creates a larger
reservoir requiring about three times as much oil to fi ll.
Lubrication is the same as for the shorter shaft, except that
two protruding screws (96) are provided to ensure
adequate splash oil for the bearing (60).
At the gear end of the blower, the bearings, seals, and
timing gears are enclosed by a gearbox containing a
double (primary and secondary) oil sump arrangement. In a
vertical-style blower, the secondary sump is formed of
sheet steel and contoured around the bottom half of the
lower gear. It is fed with oil at a controlled rate from the
surrounding primary sump in the gearbox itself, through a
metering orifice in the secondary wall. The lower gear teeth
pick up oil and carry it to the meshing point with the upper
gear, where it is splashed onto oil control shields with
leaders that direct the oil to the two bearings. A dam at
each bearing maintains the desired oil level there, with
excess overflowing into the gearbox primary sump. Inboard
sealing of the shafts is the same as at the drive end. In a
horizontal style blower, the gear end lubrication
arrangement is identical, except that a secondary sump is
formed around each gear and the total oil capacity is more
than doubled.
Note: A high-quality grade of industrial-type non-detergent,
anti-foaming oil should be used when the average of
blower inlet and discharge temperature is 125°F (52°C) or
lower. Oil should be changed after the first 100 hours of
operation. After the initial oil change, the normal oil change
periods under these conditions are every 2,000 operating
hours. At higher temperatures these oils may turn black
and leave carbon deposits. For average temperatures
above 125°F (52°C), we recommend that oil with an
efficient oxidation inhibitor be used, and that the change
interval should be reduced. Shell TELLUS is a suitable oil
type with the required characteristics. Equivalent oils from
other suppliers are assumed to be comparable in
performance.
Suggested oil change periods for the higher operating
temperatures are as follows:
Average Temp. °F (C°) Operating Hrs.
Below 150 (65) 1000
151-160 (66-71) 500
Above an average temperature of 180°F, a synthetic oil like
Roots* Synfilm ST Synthetic Oil should be used.
On the gearbox and the two opposite gear end bearings
sumps, oil levels are indicated in sight windows. All three
sight windows are completely unobstructed circular discs,
allowing the oil level to always be in view.
Approximate capacities in gallons or fluid ounces for the
three sump locations are given in Table 4 as a guide.
Actual filling requirements may vary slightly from the listed
figures.
Select a good industrial grade of oil per Table 3 for your
existing ambient temperature conditions.
To establish the correct oil levels, fill the oil sump when the
blower is not operating. At the gearbox, remove the top
vent plug (37) and pour in slightly less oil than indicated in
Table 4 for the appropriate blower size, or add the oil until it
rises to the center of the sight glass. Wait several minutes
for the levels to equalize between the primary and
secondary sumps, then add more oil if needed, or drain
excess at the plug (67).
ILRB-3000 GEA20261 RAS and RAS-J WHISPAIR Blowers.pdf 11 03/09/2015 13:21:26