Pulsafeeder Pulsalube 8 GS Ultra, Руководство по эксплуатации и техническому обслуживанию

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FLEXBLOC
™
(SI/SID SERIES) WORM GEAR
LUBRICATION GUIDELINES
RETAIN FOR FUTURE USE
U10810 - 2 of 2
www.nord.com/docs 07.23.14
NORD Gear Corporation
Toll Free in the United States: 888.314.6673
NORD Gear Limited
Toll Free in Canada: 800.668.4378
8. When to Use a Sealed or a Vented Unit
There are many conditions that should be considered when
deciding whether to use a sealed or vented unit.
1. If the duty cycle is intermittent, the run times are short,
and any build-up of internal pressure or temperature is
relatively low, the sealed unit option may be used.
2. If running continuous and under moderate to high load
conditions, worm gears can generate higher operating
temperatures and a build-up of internal pressure. In these
instances a vent is strongly recommended. Consult NORD if
operation at high load conditions is required.
3. If running continuous at 4-pole electric motor speeds (1800
rpm at 60 Hz) or higher, then a vent option is usually
recommended. Consult NORD if operation at higher
speeds is required.
4. Radial shaft seals produce a hydrodynamic pumping
action to help push lubricant back into the gear unit, caus-
ing a small amount of ingested air and a small pressure
increase (1-2 psi) that does not normally require a reducer
vent; however when combined with continuous operation
under high load (Condition 2), additional operating
pressures will result and a vent should be used.
5. When the environment is contaminated with water, dirt,
or other objects that may be ingested into the breather,
increased wear of bearings, gearing, and lubrication
breakdown can result. In these instances the sealed
option or an AUTOVENT™ should be considered.
9. Maximum Oil Sump Temperature Limit
To prevent reducer overheating, the reducer’s maximum oil-
sump temperature limit must not be exceeded for prolonged
periods of operation.
Oil Type Maximum Oil Temperature Limit
NORD AGMA 9005-D94
Synthetic 105°C (220°F) 107°C (225°F)
IMPORTANT NOTE
Use caution when specifying gear reducers for high tem-
perature service. If there is concern about exceeding the
allowable safe operating temperatures, please consult
NORD to discuss alternatives.
10. Oil Viscosity
The viscosity rating determines the operating oil’s resis-
tance to shear under load conditions. Some important vis-
cosity considerations include the following:
• Lightly loaded gears require lower viscosity oils than highly
loaded
gears.
• Lower viscosity will provide thin oil film, lower friction,
higher mechanical efficiency, and better heat removal
conditions.
• Higher viscosity will provide thicker oil film, and better
resistance to sliding wear, scuffing wear, and galling at
high pressure.
• Higher operating temperatures will cause a reduction
in viscosity and lower operating temperatures, cause an
increase in viscosity or a thickening of the oil.
The standard oil-fill is considered acceptable for most appli-
cations. In certain situations an oil viscosity change may be
beneficial.
• If the gear unit is exposed to frequent high load condi-
tions. A higher viscosity oil will have a higher film thickness
offering better overall resistance to oil shear, sliding wear
and scuffing wear in gears and roller element bearings.
• An oil viscosity correction or lubrication change may
improve the overall performance when operating the gear
unit at very low or high ambient temperature conditions.
IMPORTANT NOTE
The user should consult with their primary lubrication sup-
plier before considering changes in oil type or viscosity.
11. Viscosity Index
Viscosity index helps quantify the rate of oil viscosity change
with respect to temperature changes. Oils with a reasonably
high viscosity index tend to be more stable in a changing
temperature environment. The ability of an oil to maintain
a small viscosity differential over the operating range of the
gearbox provides a more consistent lubricating film and bet-
ter wear performance.
Synthetic oils typically have a higher viscosity index than
mineral oils and polyglycol oils tend to have an exception-
ally high viscosity index compared to other synthetic oils like
polyalphaolefin or ester based products.