Zoomlion RT35, Operator'S Manual

Page: 114 / 171

07 - 22 RT35 Rough Terrain Crane
7. 13 MAIN BOOM EXTEND / RETRACT OPERATION
A. The boom has four parts to it: a basic boom and three telescopic sections. The basic
boom section attaches to the superstructure with a pivot connection. The three
telescopic sections move together to increase the length / range of the boom. Refer to
Figure 07 – 15.
B. To extend and retract the boom, a telescoping mechanism is attached in the boom
structure. The components of the telescoping mechanism are as follows:

Telescoping cylinder

Boom extension wire-rope

Boom retraction wire-rope
C. The figure below shows the telescoping principle:
Figure 07 – 15 Telescoping Principle
1. Telescoping Cylinder
2. Boom Extension Wire-Rope
3. Boom Retraction Wire-Rope
4. Boom Retraction Wire-Rope
5. Boom Extension Wire-Rope
D. The balance valve, in the hydraulic system, helps the telescoping components move
smoothly. When the boom is set the correct length, the valve causes a blockage of the
hydraulic oil flow out of the cylinder. This helps to lock the boom in position.
E. The length detector (in the main boom, on the left side) measures the boom length
and transmits the data to the rated capacity indicator. The boom length data is
calculated then the boom configuration shows on the screen.