You will often see excavators operating on sand, gravel, mud, and even in river channels, yet they do not sink into the ground like cars do. This is because excavators use track shoes instead of tires like cars. Rather than relying on individual wheels to turn, they travel using the entire undercarriage chain together with the track shoes.
1、Understanding the Functions of Excavator Track Shoes
Load bearing: Because track shoes are rectangular, long, and wide, they can distribute the excavator’s weight over the ground more effectively and better prevent it from sinking.
Traction and propulsion: Track shoes have raised grousers that can press into soft ground. In addition, the track shoes themselves have a relatively large surface area, allowing them to provide traction for the excavator.
Protection of the ground and undercarriage: Because track shoes are relatively wide, they distribute most of the force generated during excavator operation across the surface in contact with the ground, preventing damage from being concentrated in one small area. As you can also see in the image above, because the track shoes are wide, the track links, track rollers, and drive sprockets all operate within the track shoes, reducing the risk of these parts coming into direct contact with stones.
2、Track Shoe Production Process
- Cutting the profile: Cut the full-length track shoe profile into individual pieces of the appropriate length.
- Punching: Use a punching machine to make holes, including bolt holes, in each cut track shoe.
- Heat treatment: Rapid cooling gives the parts greater hardness and strength, although the material is usually relatively brittle at this stage.
- Tempering: After quenching, the parts are reheated to a specific temperature and then cooled to reduce internal stress and improve toughness and impact resistance.
- Painting: Apply the color required by the customer. Of course, the coating used here is not merely decorative paint; it also generally provides rust protection.
- Finished product: At this stage, the product is complete and is moved to the finished-goods warehouse to await sale.
3. Selecting Excavator Track Shoes
After extended use, the grousers on the track shoes wear down, affecting the excavator’s traction. The entire track shoe may also become thinner through wear and eventually deform. When this happens, the track shoes need to be replaced promptly. Track shoes can be selected by considering the following factors.
3.1 Selection Based on the Material Used to Manufacture the Track Shoes
The raw material and steel billet are fundamental to whether the mechanical properties of the track shoes meet the required standards. Of course, the manufacturing process also affects their performance.
40CrMo alloy steel:
3.2 Selection Based on the Excavator Model
- When making a purchase, you can tell the supplier your excavator model directly, such as PC200, DH220, or E320. This will give the supplier a clearer understanding of the track shoe size and quantity you need.
- You can also tell the supplier your excavator’s operating weight, the track shoe size you want, and the detailed mounting-hole spacing.
- It is best to provide the supplier with the excavator brand and model so that the corresponding track shoes can be identified more accurately.
3.3 Selection Based on the Working Environment
- Rocky conditions: In this working environment, thicker track shoes that are not excessively wide are recommended. If the track shoes are thin and wide, they can easily become deformed when traveling over uneven gravel.
- Earthmoving projects: Because these projects generally involve a large amount of mud and sand, wider track shoes are recommended. They provide better traction and are less likely to sink too deeply into the ground.
- River channel clearing: River channels generally also fall into one of the two conditions described above: either a rocky environment or one containing more mud and sand.
- Construction sites: These are generally similar to rocky working environments, so excessively wide track shoes are not recommended.
4、Adjusting Track Tension
An excavator’s track is equivalent to its shoes. Usually, after 500 operating hours, you need to check whether the excavator’s tracks are too loose or too tight. When traveling on flat, hard surfaces such as concrete, the tracks should be adjusted slightly tighter to prevent excessive wear caused by dragging.
When traveling on soil, the tracks generally need to be adjusted slightly looser so that a larger surface area conforms to the ground and provides stronger propulsion while traveling.
What are the effects of tracks that are too loose?
If the tracks are too loose, the following may occur:
- The tracks may sway easily while the excavator is traveling;
- The engagement between the tracks, sprockets, and idlers may deteriorate;
- The tracks are more likely to derail while turning or traveling over complex terrain;
- Wear on the track shoes, track links, and other undercarriage components may increase.
Tracks that are too loose are particularly likely to accumulate soil and stones in muddy, uneven, or gravel-heavy working environments.
What are the effects of tracks that are too tight?
Tighter tracks are not necessarily better.
If the tracks are too tight, resistance in the travel system will increase, placing greater loads on the track links, track rollers, idlers, and sprockets. It may also accelerate wear throughout the undercarriage system.
Therefore, the key to track adjustment is not to make the tracks “as tight as possible,” but to keep them within the reasonable range specified by the manufacturer.
How to Check Track Tension
Lift one side of the excavator’s track off the ground. After the track hangs naturally, there should be a gap of 5-8 centimeters between the track and the track roller.
How to Adjust Track Tension
When adjusting the track, the operator can usually raise one side of it. The specific procedure is as follows:
- Rotate the cab 90-120 degrees
- Lift the track off the ground
- Use a wrench to loosen the screw on the track adjuster cylinder
- Pump grease in until the track reaches the appropriate position
- Tighten the screw
5、Installing Rubber Pads on the Track Shoes
When traveling on hard surfaces, track shoes generally experience greater friction and wear more easily. Adding rubber pads to the track shoes can therefore extend their service life while also protecting the ground from damage.
Improved Travel Stability
After rubber pads are installed on the excavator’s track shoes, friction between the tracks and the ground is greatly increased, providing better traction and helping to prevent slipping.
Reduced Noise and Vibration
Some small excavators are commonly used indoors. After rubber pads are installed, the excavator no longer produces harsh noises while traveling, making it more environmentally friendly to the surrounding area.
6、Regularly Cleaning Debris from the Track Shoes
Excavators generally operate on complex terrain, so debris often enters the track shoes and stones become lodged in them. Mud, sand, and other debris can enter the tracks and excavator undercarriage, reducing the service life of their components. Stones also frequently become lodged in the track shoes. If they are not removed promptly, they can cause the track shoes to deform.
Why do the tracks need to be cleaned?
Regularly cleaning the tracks can:
- Reduce the accumulation of soil and stones;
- Prevent foreign objects from interfering with the engagement between the sprockets and track links;
- Reduce abnormal wear on undercarriage components;
- Make cracks and deformation in the track shoes easier to identify;
- Make it easier to check whether bolts are loose;
- Extend the service life of the track system.
7、Checking the Track Shoes for Damage
Regularly check the track shoes for cracks or breakage. If any problems are found, replace the track shoes promptly.
Track shoes bear the machine’s full weight and withstand impacts from the ground over long periods, making them typical high-load wear components.
The impact on the track shoes increases significantly in environments such as mines, quarries, and rocky terrain.
Focus on Checking the Following Issues:
① Cracks in the Track Shoes
If obvious cracks are found in a track shoe, they should be addressed promptly.
② Broken Track Shoes
A track shoe that has already broken must not continue to be used for an extended period, as it may affect the entire track system.
③ Bent Track Shoes
Severely deformed track shoes may interfere with normal track operation and may also increase the load on other undercarriage components.
④ Abnormal Track Shoe Wear
If the track shoes on one side or several individual track shoes show clearly abnormal wear, the track tension, undercarriage components, and working environment need to be inspected further.
8、Checking Whether the Track Shoe Mountings Are Loose
Before starting work each time, check whether the track shoe bolts are loose. If they become loose or fall out, continuing to operate the machine by force will cause components to become misaligned, resulting in irreversible damage.
9、Summary
Although an excavator track shoe may appear to be a relatively simple undercarriage component, it directly affects the excavator’s travel performance, stability, operating efficiency, and undercarriage service life.
During daily use, special attention should be paid to track tension, track shoe wear, track shoe bolts, the condition of the rubber pads, and any mud or stones inside the tracks.
At the same time, different types of track shoes should be selected for different working environments. Only the combination of the right product + correct installation + regular maintenance + reasonable operating practices can genuinely extend the service life of the track system.
For construction companies, equipment distributors, and construction machinery maintenance personnel who need to use excavators over extended periods, regularly inspecting the track shoes and promptly replacing worn components are important measures for reducing the risk of equipment downtime.