Hyundai HX130LCR Manual page 51

2. FUNCTION
MAIN PUMP
1)
The pumps may be classified roughly into the rotary group performing a rotary motion and working
as the major part of the whole pump function: the swash plate group that varies the delivery rates:
and the valve cover group that changes over oil suction and discharge : and the PTO group that
transfers drive shaft of gear pump.
(1) Rotary group
The rotary group consists of drive shaft
(F) (111), cylinder block (141), piston
shoes (151,152), set plate (153),
spherical bushing (156) and cylinder
spring (157). The drive shaft is supported
by bearing (123,124) at its both ends.
The shoe is caulked to the piston to from
a spherical coupling. It has a pocket to
relieve thrust force generated by loading
pressure and to take hydraulic balance so
that it slides lightly over the shoe plate
(211). The sub group composed by a
piston and a shoe is pressed against the
shoe plate by the action of the cylinder
spring via the set plate and a spherical
bushing.
Similarly, the cylinder block is pressed
against valve plate (313) by the action of
the cylinder spring.
(2) Swash plate group
The swash plate group consists of swash
plate (212), shoe plate (211), swash plate
support (251), lock pin (255), tilting
bushing (214), tilting pin (531) and servo
piston (532).
The swash plate is a cylindrical part
formed on the opposite side of the sliding
surface of the shoe and is supported by
the swash support.
If the servo piston moves to the right or
left as hydraulic force controlled by the
regulator connects to hydraulic chamber
located on both sides of the servo piston,
the swash plate slides over the swash
plate support via the spherical part of the
tilting pin to change the tilting angle (α)
211
111
123
251
255
532
212
251
2-7
124
313
141
156
153
157
151
152
21092MP06
531
548
214
212
α
α
140Z92MP09
211