Hydraulic excavator is a kind of widely used construction machinery, active in road construction, bridge construction, housing construction, rural water conservancy, land development and other fields. It can be seen everywhere in the construction of airports, ports, railways, oil fields, highways, mines, and reservoirs.
Many excavator operators learn the excavator from their masters. They are very skilled in the operation of the excavator, but they don’t know much about the overall structure and principles of the excavator. The series of knowledge articles, a total of 5 sections, will explain the basic knowledge of excavators from the aspects of excavator classification, chassis assembly, working device assembly, upper platform assembly, hydraulic basic knowledge, etc. from the shallower to the deeper.
1. Classification of excavators
1. According to the operation method: single-bucket excavator and multi-bucket excavator, the common excavator is single-bucket excavator, only large-scale mines use bucket-wheel excavator, there are many buckets, and rotary operation
The common one is single bucket excavator (Carter 320D)
Multi-bucket excavator for large mines
2. According to the driving mode: internal combustion engine drive, electric drive, compound drive (hybrid)
Commonly driven by an internal combustion engine (diesel engine)
Mining electric shovel (front shovel excavator)
3. According to the way of walking: crawler type and tire type
4. According to the working device: front shovel and back hoe
2. Introduction to the structure of the excavaor
Names of parts of the excavator
The whole machine can be divided into three parts structurally: chassis assembly, working device assembly, and upper platform assembly.
The composition and function of the chassis assembly:
1. Support the weight of the upper part of the excavator.
2. Power source and actuator for walking and steering.
3. Support the reaction force of the working device during excavation.
The main components of the chassis:
1. The lower frame body (welding parts),
2. Four wheels and one belt (guide wheels, driving wheels, supporting sprockets, rollers, crawlers).
3. Dozer blade and cylinder.
4. Central rotary joint.
5. Swivel raceway ring (slewing bearing).
6. Travel reducer and motor.
Exploded view of main components of chassis assembly
Frame structure and function: Frame body (welding parts) —– the main body of the entire chassis, bearing all internal and external forces and various moments, the working conditions are extremely harsh, and the requirements for the parts are high. There are certain requirements for the parallelism of the left and right crawler beams, otherwise a large lateral force will occur, which will be unfavorable to the structural parts
4~Four wheels and one belt, slewing support
Guide wheel and tensioning device: Guide wheel and
tensioning device: guide the direction of track movement, adjust the degree of tension of the track, and reduce resistance.
IDLER and tensioning device
Carrier sprockets and track rollers: The carrier sprockets play the role of supporting the track. Rollers play the role of supporting weight
Carrier roller and track rollers
This structure is a maintenance-free structure, without adding grease.
The structure of the supporting sprocket and the supporting wheel for large excavators is slightly different, but the principle is the same.
Sprocket : drives the whole machine to walk and turn
Track link Assy
Slewing bearing
—-Connect the upper car and the lower car, so that the upper car can rotate around the lower car and bear the overturning moment at the same time.
The rollers (balls) in the orbital ring need to be lubricated regularly, and there are two forms of adding butter from the side and adding butter from the top.
Traveling motor + reducer: provide powerful power (torque) to drive the sprocket and crawler belt, so that the excavator can complete the walking and steering actions.
Post time: Dec-24-2022
