8. Lubrication

1
8. Lubrication

• Purpose of Lubrication
• to prevent metal to metal contact in gears and
  bearings.
• to reduce friction, no-load, and load losses.
• to dissipate the heat generated by gears and
  bearings.
• to prevent corrosion.
• catching dirt and abrasive materials.
• lubricate sealings.

2
8. Lubrication

• Different Lubrication Systems are dictated by
• Gear pitch velocity v m/s (d mn rpm) /
  19,1
• Operational conditions
• Absorbed power
• Speed
• Ambient temperatureand temperature range
• Duty cycle
• Max. oil temperature
• Oil types
• .....
• Mounting position

3
8. Lubrication

• Lubrication Systems
• Splash lubrication
• Bath lubrication
• Forced lubrication
• Pressure lubrication
• Circulation lubrication

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8. Lubrication

• Lubrication systems
• Splash lubrication
• only the gear of the LSS and maybe some
  intermediate shafts immerse in oil.
• these immersing gears splash the oil to all
  rotating elements.
• most commonly used, especially for horizontal
  mounted gear units.
• For pitch line velocity v lt 15 m/s

Gear
v
Oil Level
Source Training Material 1998
5
8. Lubrication
Gear

• Lubrication systems
• Bath lubrication
• all rotating parts must be in contact with oil,
  e.g. bearing rollers must go under oil level when
  operating.
• Oil level can also be above all rotating
  elements.
• option for vertical and upright mounted units.
• for pitch line velocity v lt 6 m/s for 1- and2-
  stage units.
• For pitch line velocity v lt 8 m/s for 3-, 4- and
  5- stage units.

v
Minimum oil level
Bearing
Possible oil level
Source Training Material 1998
6
8. Lubrication

• Lubrication systems
• Bath lubrication - Examples
• Oil needs room for expansion.
• In case gear unit is full ? additional need for
  expansion area or expansion tank

SEW Upright MC..R-gear unit
SEW Vertical MC..P/R-gear unit for humid
conditions
SEW Vertical MC..PS gear unit
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8. Lubrication
Lubrication systems Bath lubrication - Examples
Flender Agitator gear unit
Flender Travel Drive 3-stage
8
8. Lubrication

• Lubrication systems
• Forced lubrication
• Oil is pumped by means of a pump directed in the
  middle of the bearings and the gear mesh.
• The pump can be shaft driven or electric driven
  (motor pump).
• For pitch line velocity helicals v gt 15 m/s
• For pitch line velocity bevels v gt 12 m/s
• If separate cooling is necessary.
• Unfavorable bearing or gearing arrangement.
• Bath lubrication not possible due to high speed
  or unacceptably large oil volume.
• Basically possible for all mounting positions.
• SEW uses exclusively pressure lubrication.

Gear
v
Pump
Oil level
Bearing
Source Training Material 1998
9
8. Lubrication

• Lubrication systems
• Forced lubrication - Examples
• With shaft end pump
• With motor pump

Vertical SEW-MC3PV-gear unit with shaft end pump
Vertical Hansen P4 gear unit with integrated
shaft end pump
shaft end pump
Horizontal SEW-MC..P/R-gear unit with motor pump
shaft end pump
Vertical Flender gear unit H3BV.. with shaft end
pump
motor pump
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8. Lubrication

• Oil Lifetime

• CLP Mineral Oil
• CLP HC Synthetic OilHC-basis,lifetime
  equivalent to PAO-basis
• CLP HC Synthetic OilPG-basis

1. Operation Hours
2. Continous Oil Bath Temperature

Source Manual MC-range
11
8. Lubrication

• Oil Viscosity Selection Issues
• Minimum Starting Temperature
• Splash Lubrication maximum oil viscosity has to
  be limited because of the insufficient flow of
  the oil through the gear unit.
• Forced (Pressure) Lubrication the maximum
  starting viscosity is limited to avoid cavitation
  in the suction line of the oil pump.
• Maximum Operating Temperature
• Oxidation of the oil and its additives.
• Oil Film Thickness a minimum oil viscosity is
  required to prevent direct metal-metal contact
  between the surface of the gear teeth in mesh and
  between the rollers and the racer rings of the
  bearings.

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8. Lubrication

• Lubrication of Industrial Gears
• all bearings are oil lubricated.? different then
  AD-adapter geared motors.
• Exception
• drywell-sealing system lower LSS-bearing
  grease lubricated with regreasing facility.
• Special requirements.