Knowledge of undercarriage parts for excavator

The four wheels in “four wheels and one belt” refer to sprocket, idler, track roller and carrier roller. Belt refers to the track group. They are directly related to the working performance and walking performance of the excavator, and its weight and manufacturing cost account for a quarter of the manufacturing cost of the excavator itself.

The power of the hydraulic excavator engine is transmitted to the TRACK GROUP through the traveling motor and the driving wheel. It is required that the driving wheel and the chain rail of the TRACK GROUP are properly meshed, the transmission is smooth, and the TRACK GROUP can still be well meshed when the pin sleeve is worn and stretched. The phenomenon of “jumping teeth”. The sprockets of the track running gear are usually placed at the back. In this way, the length of the tensioning section of the track can be shortened, the power loss can be reduced, and the service life of the track can be improved. According to the structure, it can be divided into integral type and split type.

The idler is used to guide the track to run correctly, which can prevent it from deviating and deviating from the track. Most of the hydraulic idlers also play the role of rollers, which can increase the contact area of ​​the track to the ground and reduce the specific pressure. , The wheel surface of the idler is mostly made of smooth surface, and there is a shoulder ring in the middle for guiding. The torus on both sides can support the rail chain and play the role of a roller. The smaller the distance between the closest rollers, the better the idler performance
Advantages: In order for the idler to function and prolong its life, the radial run out of the wheel facing the center hole should be less than or equal to 3MM, and it should be correctly centered during installation.

3.Track Roller:
The function of the rollers is to transmit the weight of the excavator to the ground. When the excavator is driving on uneven roads, the rollers will be impacted by the ground. Therefore, the rollers are subject to large loads and poor working conditions, often in dust. Sometimes it is also soaked in muddy water, so a good seal is required.
Features: most of them are supported by sliding bearings. And dustproof with floating oil seal.
Generally only need to add butter once during an overhaul period, which simplifies the usual maintenance work of the excavator.

4.Carrier Roller
The function is to hold the TRACK GROUP up, so that the TRACK GROUP has a certain degree of tension.

5.Track Group:
The TRACK GROUP is to transmit the gravity of the excavator and the load of working and walking to the ground. Excavators can be divided into steel TRACK GROUP and rubber TRACK GROUP according to the material. The steel TRACK GROUP has good wear resistance, convenient maintenance and good economy, so it is widely used. Rubber TRACK GROUP is generally used on small hydraulic excavators to protect the road from damage.
The track shoes for steel track classification: there are two kinds of integral type and combined type. The integrated TRACK GROUP track shoes has meshing teeth, which tend to mesh with the sprocket, and the track shoe itself becomes the rolling track of wheels such as rollers. Its characteristics are: easy to manufacture, but fast wear.
Now the multi-purpose combination of excavators is characterized by small pitch, good revolving, and fast walking speed of excavators. Long service life, the material of the track shoe is mostly rolled plate which is light in weight, high in strength, simple in construction and cheap in price. Rolled sheets are available in Shuzhong materials such as single-bar, double-bar and triple-bar. Now excavators use three ribs. Its characteristics are that the height of the ribs is small, the strength of the track shoes is large, the movement is smooth, and the noise is small.
There are 4 connecting holes on the track plate, and there are two cleaning holes in the middle, which are used to automatically remove the clay. There are overlapping parts between the two adjacent track shoes, and the two adjacent track shoes are made into overlapping parts. Prevent excessive tension from being sandwiched between the tracks.
The excavator on the wetland can use the triangular TRACK GROUP shoe, and its cross section is triangular, which can be compacted on the soft ground and improve the supporting capacity.

Based on the above knowledge, we can roughly understand the basic knowledge of the four-wheeled area, and have a general understanding of the four-wheeled area.
As an excavator, the chassis walking device of the bulldozer accounts for a quarter of the manufacturing cost of the whole machine, which shows its importance.

Post time: Jun-08-2022