Komatsu Galeo PC800-8, Shop Manual

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36
PC800, 850-8
SEN00383-03
10 Structure, function and maintenance standard
1. Hydraulic motor unit
Function
• This hydraulic motor is called a swash plate type
axial piston motor. It converts the energy of the
pressurized oil sent from the hydraulic pump into
rotary motion.
Principle of operation
• The oil sent from the hydraulic pump flows
through valve plate (7) into cylinder block (5).
This oil can flow on supply side of the
Y-Y line
connecting the top dead center and bottom dead
center of the stroke of piston (4).
• The oil sent to supply side of cylinder block (5)
presses pistons (4) (4 or 5 pieces) and generates
force
F1 ( F1 kg = P kg/cm
2
x
x
/4 D2 cm
2
).
• This force is applied to thrust plate (2).
• Since thrust plate (2) is fixed to the angle of (a)
degrees to output shaft (1), the force is divided
into components
F2 and F3 .
• The radial component F3 generates torque
against the Y-Y line connecting the top dead
center and bottom dead center ( T = F3 x ri ).
• The resultant of this torque [ T = ( F3 x ri )] ro-
tates cylinder block (5) through the piston.
• Since cylinder block (5) is coupled with the out-
put shaft by means of spline, the output shaft re-
volves to transmit the torque.