CRAWLER EXCAVATOR

SHANDONG TONGWU MACHINE EQUIPMENT CO., LTD

1

Chapter I Usage Features and Performance Parameters of Mini Excavators

Section I Usage and features

Section II Main performance parameters

Chapter II Basic Structure and Work principle of Mini Excavators

Section I Overview

Section II Work principle

Section III Basic structure of mechanical system

Section IV Basic structure of hydraulic system

Chapter III Service Technologies of Mini Excavators

Section I Basic construction knowledge

Chapter VII Troubleshooting of Mini Excavator

Section I General

Section II Troubleshooting of mechanical system

Section III Troubleshooting of hydraulic system

Section IV Troubleshooting of electrical control system

Section V Troubleshooting of engine

Section VI Other

Attachment: BOM List of Mini Parts

2

Main application: farming, landscaping, ditching and fertilization in garden, vegetable greenhouse, agricultural

transformation, indoor demolition, small earthwork, civil engineering, road recovery, basement and indoor

construction, concrete breaking, burying of cable, laying of water supply line, garden cultivation, desilting and

other applications.

These excavators are equipped with powerful diesel engines, domestic main pumps and rotary motors, Eton (USA)

traveling motor.

The Mini model is equipped with multiple attachments, such as quick hitch, log grab, leveling bucket, auger,

standard bucket and narrow bucket. An optional rake and ripper are also available on request.

3

4

5

6

The Mini excavator is composed of a power train, work implements, swing mechanism, control mechanism, drive

system, traveling mechanism and auxiliary equipment, as shown in fig. 1-1. Mounted on the rotary table

full-swing base are the main components of the drive system, swing mechanism and auxiliary devices, which are

referred to as the upper rotary. So, our Mini excavator is divided into work equipment, upper rotary and traveling

mechanism.

7

hydraulic energy) —— distributor valve—— swing motor (hydraulic energy changed to mechanical energy)

—— slewing bearing —— realizing of wing

3. Boom power route: diesel engine —— coupler —— hydraulic pump (mechanical energy changed to

hydraulic energy) —— distributor valve —— boom cylinder (hydraulic energy changed to mechanical

energy)——boom movement

4. Arm power route: diesel engine —— coupler —— hydraulic pump (mechanical energy changed to hydraulic

movement

5. Bucket power route: diesel engine ——coupler —— hydraulic pump (mechanical energy changed to

hydraulic energy) —— distributor valve —— bucket cylinder (hydraulic energy changed to mechanical

8

2 Drive system

The Mini excavator's drive system transfers the output power from the diesel engine, through the hydraulic system

to the work equipment, swing mechanism and traveling mechanism.

3 Swing mechanism

The Swing mechanism turns the work equipment and upper rotary in left and right directions, to allow excavating

and unloading. The Mini excavator’s swing mechanism fixes the rotary table onto the frame allowing it to swing

without any inclining risk. The machine is equipped with slewing supports and a slewing drive (power of turntable

slewing), known as the swing mechanism.

3.1 Slewing support

The Mini excavator has its rotary table supported with a rolling bearing, allowing the swinging of upper

4 Traveling mechanism

steers around the braked track; when the two motors run in reverse, the excavator rotates in situ.

As the main component of the excavator, the integrated skewed boom is adopted on to the Mini excavator,

Chapter III Service Technologies of Mini Excavators

Under normal operating conditions, the Mini excavator’s hydraulic oil temperature can reaches as high as 85℃,

16-18MPa. So the operator should be properly trained with the appropriate certification, and should be familiar

with the contents of this manual before operation. In addition, maintenance and repair of excavator should be

strictly in line with the regulations in this manual to avoid any accident or damage.

There are four basic movements: bucket rotation, arm stretching / backing, boom lifting / lowering and turntable

2) Startup and stop should be easy and accessible to the driver.

3) Easily accessible visual operations. In general, the operational force on the handle does not exceed 40～

4) The control mechanism should minimize the deformation of its lever, as well as the inside clearance and

5) Ensure the operational performance does not change in temperatures between -40～50℃.

1. Inspection before startup

In order to prolong its service life, check the following before startup:

2. Maintenance before startup

Before startup each shift, it is required to grease the work equipment and the slewing bearing.

3. Preheating of machine on cold days

If it is cold, the engine will be difficult to start, or the fuel may be frozen and hydraulic oil may increase its

viscosity. Therefore, selection of fuel is dependent on environmental temperature.

When hydraulic oil is less than 25℃, you must preheat the machine before any work; otherwise the

machine may not respond or react very quickly, leading to possible accident.

1. Traveling

Use the traveling levers.

(1) Straight

Moving the lever forwards or backwards, operates the machine forwards or backwards.

A. Left turn in situ: backward shift the left lever and forward push the right lever.

b. Right turn in situ: backward shift right lever and forward push the left lever.

d. Right turn with right track as axis: forward move the left lever

2. Excavation

2.1 Slewing and the work equipment are respectively controlled with two levers, with positions shown below:

2.2 Basic excavation

1. Before excavation, the arm cylinder should be at 90° to the arm, and the bucket 30° to the ground being

excavated. Only in this situation, can each cylinder achieve maximum power.

2. To excavate any soft soil, the bucket should be angled with the soil at 60°, thereby increasing work

efficiency.