Oil / Lubrication - Honda G100K2 Applications Manual

OIL / LUBRICATION

FUNCTION OF OIL
Ø REDUCES FRICTION
Ø DISTRIBUTES FORCE
As the load on ball bearings, roller bearings, chains, etc. is on a point or across a surface, a large force is
applied to the contact point. Oil enlarges the area to which the force is applied and distributes force to
prevent concentration at one point.
Ø COOLING
Oil cools the friction surfaces by carrying away heat generated on, or delivered to the surface.
Ø PREVENTS CORROSION
Oil film covers metal surfaces to prevent contact with the air.
Ø SEALING
Piston rings seal the high pressure of combustion. Oil assists ring sealing.
Ø CLEANING
Carbon and sludge accumulates and is distributes throughout the oil, thus preventing solidification.
Ø TRANSMISSION AND ABSORPTION OF POWER
Oil in an hydraulic torque converter functions as a medium to transmit power smoothly (e.g. hydrostatic
transmission).
Oil in a shock absorber functions to absorb energy.
OIL VISCOSITY
Viscosity is an essential feature of oil.
- High viscosity :
- Low viscosity :
- Relationship of viscosity and temperature.
When temperature decreases, the viscosity
increases and power loss increases.
An appropriate oil should be selected
according to the ambient temperature.
Force or electric power required to start the
engine in cold conditions is affected by the
viscosity of the engine oil.
The viscosity grade of oil most suited to the
ambient operating temperature must be used.
oil film is strong (effectiveness as a lubricant is good)
fluidity is poor (resistance is large and power loss is excessive)
oil film is weak (effectiveness as a lubricant is poor)
fluidity is good (resistance and power loss are small)
Possible starting
range
Low - - - - - - Oil viscosity - - - - - - High
- 52 -
Difficult starting
range