Hyundai HX130LCR Manual page 102

4) BRAKE SYSTEM
(1) Control valve swing brake system
This is the brake system to stop the swing motion of the excavator during operation.
In this system, the hydraulic circuit is throttled by the swing control valve, and the resistance
created by this throttling works as a brake force to slow down the swing motion.
Work
A B
MCV
MCV A, B opened
(2) Mechanical swing parking brake system
This is function as a parking brake only when the swing control lever and arm in control lever are
not operated.
Brake assembly
①
Circumferential rotation of separate plate
(14) is constrained by the groove located
at casing (1). When housing is pressed
down by brake spring (16) through
friction plate (13), separate plate (14)
and parking piston (15), friction force
occurs between friction plate and
separate plate.
Friction force constrains motion of
cylinder block (8). When hydraulic force
exceeds spring force, brake is released.
Deceleration
A B
MCV
MCV A, B throttled
16
8
15
14
13
1
1 Casing
8 Cylinder block
13 Friction plate
2-58
Stop
A B
MCV
MCV A, B closed
2-48(1)
Groove
140WF2SM35
14 Separate plate
15 Parking piston
16 Brake spring