Hyundai r35z-7 Workshop Manual page 86

(2)
When running at 2nd speed (high speed)
When control valve is set to the 2nd speed position, the pressure oil delivered by the pump is led
to spool (41) and spool (41) is switched to the position shown below in the figure. And the
pressurized oil flows into each ports Pi1 and Pi2 through ports M1 and M2 and the motor driving
pressure (P1 : high pressure and P2 : low pressure) is led to each swash plate control piston (19).
Therefore the force pushing up the swash plate acts on swash plate control piston (19).
Fp1 = Ap P1
When steel ball (6) is placed on the tilting center, the balance of moment acting on swash plate (5)
is in the condition of ( F+Fs1) L1 < (Fp+Fs2) Lo depending on the total
piston sub assy (15).
The face "b" of swash plate (5) stabilizes and the swash plate angle become , consequently the
motor speed is the 2nd speed (high speed).
While the engine is stopped, spool (41) is returned to the 1st speed position by the force of spring
(9) since pressurized oil does not flow. When steel ball (6) is placed on the tilting center, the
balance of moment acting on swash plate (5) is in the condition of Fs L1 > Fp Lo, the face "a"
of swash plate (5) stabilizes and the swash plate angle become , consequently the motor speed
at starting is always the 1st speed.
Valve plate(25)
Port C(Low pressure)
Port B(High pressure)
F F p2 = Ap
M2
M1
Pi2
Pi1
Face c
Piston
sub assy(15)
F + Fs1
Spring(9)
Swash plate(5)
At 2nd speed(high speed)
2-54
P2
Spool(41)
Spring(42)
Face b
Steel ball(6)
L1
L
0
Fp + Fs2
Spring(20)
Swash plate control piston(19)
Face a
F of driving force of
Low pressure
R35Z72TM21