Komatsu Galeo PC800-8 Shop Manual page 132

SEN00383-03
Function
• The engine speed and torque are transmitted to
the shaft of this pump. Then, this pump converts
the speed and torque into oil pressure and dis-
charges pressurized oil according to the load.
• It is possible to change the delivery by changing
the swash plate angle.
Structure
• Cylinder block (7) is supported to shaft (1) by
spline (17).
• Shaft (1) is supported by front and rear bearings
(18).
• The end of piston (6) has a spherical hollow and
is combined with shoe (5).
• Piston (6) and shoe (5) form a spherical bearing.
• Shoe (5) slides along an elliptic orbit while being
kept pressed against plane (A) of rocker cam (4).
• Rocker cam (4) brings high pressure oil at cylin-
der surface with cradle (2), which is secured to
the case, and forms a static pressure bearing
when it slides.
10
10 Structure, function and maintenance standard
• Piston (6) carries out relative movement in the
axial direction inside each cylinder chamber of
cylinder block (7).
• Cylinder block (7) seals the pressurized oil to
valve plate (9) and carries out relative rotation.
• This surface is designed so that the oil pressure
balance is maintained at a suitable level.
• The pressurized oil inside each cylinder chamber
of cylinder block (7) is sucked in and discharged
through valve plate (9).
• Impeller pump (14) and impeller pinion (16) are
united by impeller shaft (15) and connected to
shaft (1) through bevel gear (13).
• They rotate along with the shaft. Thus, they help
supplying the sucked pressurized oil to cylinder
block (7) and also help sucking it there by use of
centrifugal force.
PC800, 850-8