Komatsu ecot3 PC300LC-8 Shop Manual page 105

10 Structure, function and maintenance standard
Function
q The pump converts the engine rotation trans-
mitted to the shaft to oil pressure and delivers
pressurized oil corresponding to the load.
It is possible to change the discharge amount
q
by changing the swash plate angle.
Structure
Cylinder block (7) is supported to shaft (1) by
q
spline (14).
q Shaft (1) is supported by front and rear bear-
ings (15).
Tip of piston (6) is shaped as a concave ball
q
and shoe (5) is caulked to it to form one unit.
q Piston (6) and shoe (5) constitute the spherical
bearing.
q Rocker cam (4) has flat surface (A), and shoe
(5) is always pressed against this surface while
sliding in a circular movement.
q Rocker cam (4) conducts high pressure oil to
cylinder surface (B) with cradle (2), which is
secured to the case, and forms a static pres-
sure bearing when it slides.
PC300, 350-8
Piston (6) carries out relative movement in the
q
axial direction inside each cylinder chamber of
cylinder block (7).
q Cylinder block (7) seals the pressurized oil to
valve plate (8) and carries out relative rotation.
q This surface is designed so that the oil pres-
sure balance is maintained at a suitable level.
q The oil inside each cylinder chamber of cylin-
der block (7) is suctioned and discharged
through valve plate (8).
SEN01993-00
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