Service Manual

Heat
Rise
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.
Filter
I
Filter
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