Hyundai HX145LCR Manual page 123

3. PRINCIPLE OF DRIVING 3. PRINCIPLE OF DRIVING
Travel motor comprises with rotary, relief valve, parking brake, counterbalance valve and 2-speed
control.
1) 1) WORKING OF ROTARY PART WORKING OF ROTARY PART
In the figure below, axis directional force F1 occurs when the high pressure oil flows into the
cylinder block through to the valve plate (1) port, and the piston moves to the left hand side.
This force F1, which takes shoe (3) as a medium, split into axial force F which is parallel with a
shaft, and radial force F2 which is perpendicular to the shaft. By the reaction force F2, cylinder
block rotate with piston and shoe, while shoe (2) moves on the shoe plate with piston.
There are 9 pistons inserted into the cylinder block and they rotate with the cylinder block by taking
high pressure oil in order at the entrance. When the oil flow is reversed, piston and cylinder block
rotate in the opposite direction.
Piston
F2
Swash Shoe(2)
plate
IN
High
pressure
fluid
F1
F
High pressure
Low pressure
Valve
Cylinder
block plate(1)
pressure
A
fluid
fluid
2-71
Low
High
pressure
fluid fluid
B A
145Z9A2TM03