Hyundai HX145LCR Manual page 118

(4) (4) High/low speed changeover mechanism High/low speed changeover mechanism
①
At low speed - pilot pressure of less than 10 kgf/cm At low speed
When no pilot pressure is supplied from (D) (at a pressure of 10 kgf/cm
pressed toward the top by the force of spring (66) and (A) port or (B) port, the pressurized oil
supply port (C) is shut off, and oil in chamber (P) is released into the motor case via
valve(65). Consequently, swash plate (3) is tilted at a maximum angle ( 1) and the pis-
ton displacement of hydraulic motor becomes maximum, thus leading to low-speed rotation.
A
②
At high speed - pilot pressure of 20 kgf/cm At high speed
When a pilot pressure is supplied from port (D) (at a pressure of 20 kgf/cm
overcomes the force of spring (66) and (A) port or (B) port of valve (65) is pressed toward the
down. The pressurized oil at supply port (C) is then introduced into chamber (P) via valve (65). Pis-
ton (61) pushes up swash plate (3) until it touches side Y of the spindle. At this time, swash plate (3)
is tilted at a minimum angle ( 2) and the piston displacement of hydraulic motor becomes mini-
mum, thus leading to high-speed rotation.
A
B
C
A
B
Drain
B
C
A
B
2
D
Pilot pressure
66
65
2 or more
D
Pilot pressure
66
65
2-66
2 or less), valve (65) is
1
Y side
61
3
P
2 or more), the pressure
X side
61
3
P
14092TM10
14092TM11