Doosan DX22 - Belt Tension; Other;Driving System

4. Regular Inspections
47
Other/Driving System
Belt tension
Belt tension is maintained by an auto tensioner, so there is
no need to adjust it. The belt must be replaced when the
pointer indicates that a replacement interval is approaching.
1. Inspection conditions
1) Check the belt for cracks, oil residue, deformation due to
heat, and wear.
2. The vertical bar (A) indicated by the arrow is the "pointer".
When this "pointer" enters the horizontal range (B) indi-
cated in orange, the belt must be replaced.
EDL022140A
EDL022140A
1) The tension of the belt should be adjusted to the amount
of deflection of the belt when the specified force (F) is
applied to it.
2) Adjust the belt so that (T) = 0.015 × S (1.5 mm per 100
mm).
Note) T : Deflection amount, S : Distance
3)
Note) C : Center distance (mm), D : Large pulley dia. (mm), d :
Small pulley dia. (mm)
3. Measuring Tension
EDL022141A
1) Insert the belt into the protrusion (A) of the tension
measuring instrument.
• Place the measuring instrument between the pulleys and
set its contact end (B) to push the belt.
• Press the pad (C) slowly until the sound of the spring
unscrewing is heard. This force pushes the tension
measuring instrument upward.
• If there is still tension left on the belt after removing the
pad (C), the measurement is not accurate.
2) Measuring Tension
• Read the tension value at the point where the top of the
protrusion (A) of the tension measuring instrument is
aligned with the scale.
• Before reading the tension value, make sure that the
needle of the measuring instrument has returned to the
original position.
3) Adjusting Tension and Replacing the Micro-V Belt
• Rotate the auto tensioner clockwise using the square
groove in the center of the idle pulley of the auto tensioner.
• Remove the old belt.
• After fitting the new belt onto all of the pulleys (check to
make sure the belt covers all of the belt grooves), rotate
the auto tensioner clockwise to wrap the belt around the
auto tensioner; then, fit the tightened auto tensioner in
place.
A
B
*S= C
2
(D - d)
2
2
A
C
B