Efficiency; Hydraulic Components; Reservoir; Filter - Kohler K91 Owner's Manual

Heat Ri s e
Efficiency
Efficiency describes the amount of power
output from the hydraulic system as compared
to the amount of power put into it.
Most hydraulic pumps and motors operate
between 80% to 90% efficiency. The loss of
power is made up by leakage and fluid friction.
This friction causes a heat rise in the system.
As a pump or motor wears internally, it becomes
less efficient and the operating temperature
increases.
Power In Power Out
+
Heat Rise
How Big Is A Micron?
8
Microns
25
Microns
Red Blood Cell
White Blood Cell
0
100 Microns 70
Microns
40 Microns
Grain Of Salt Human
Hair Lower Limit Of Visibility
1 Micron 0.00003937" or 0.001 mm
HYDRAULIC COMPONENTS
Reservoir
The reservoir is a simple, yet very important
component of any hydraulic system. It serves as
an expansion chamber, and separates trapped
air from the fluid.
Some systems use the gear case as a reservoir.
This allows dirt and metal filings to settle out of
the fluid. This type of reservoir allows for more
fluid capacity which in turn assists in keeping
the system properly cooled.
Reservoirs are generally vented and should
prevent dirt or water from entering the system.
Fi l t er I Fi l t er
Hydraulic filters are special purpose filters which
are able to entrap extremely small particles of
dirt. A typical hydraulic filter will trap particles as
small as 25 microns or less. Most engine oil
filters only trap particles larger than 70 microns.
Hydraulic filters do not have a bypass valve like
an engine oil filter. When a hydraulic filter
becomes clogged, oil flow is reduced and erratic
operation will be evident.
Productivity Series
a