Do you know the maintenance of the undercarriage part of the excavator

Do you know the maintenance of the undercarriage part of the excavator?

Learn this little common sense, it will make your work more efficient

Today, let’s talk about the maintenance and precautions of the chassis part of the excavator. Although the chassis part is a little iron guy, it is also very important to the excavator, and it is also the most easily overlooked. The chassis part is mainly divided into: track roller, carrier roller, guide wheel, driving wheel, track, commonly known as the four-wheel area.

Track Roller

The outer wheel of the roller and the main shaft are supported by a floating oil seal

The rollers are located under the X-frame of the excavator. Generally, there are seven 20-ton rollers on one side. Two of them have crawler chain rail guards. In daily work, try to avoid the rollers being immersed in muddy water, ice and snow for a long time. After the work is completed every day, the unilateral crawler should be propped up, and the walking motor should be driven to shake off the mud and other debris on the crawler.

Especially in winter construction, the roller must be kept dry, because there is a floating seal between the outer wheel and the shaft of the roller. If there is water, it will freeze at night. When the excavator is moved the next day, the seal and the ice will contact. Scratches lead to oil spills, which is why oil spills from rollers mostly occur in winter. Damage to the rollers will cause many failures, such as excessive damage to one side of the rollers, and the excavator may walk off-track and walk weakly.

2. Carrier Roller

The carrier wheel is located at the platform position above the X frame, and its function is to maintain the linear motion of the chain rail. If the carrier wheel is damaged, the track chain rail will not be able to maintain a straight line, which is what we often call the chain loss. The carrier wheel is a one-time injection of lubricating oil. If there is oil leakage, it can only be replaced with a new one. Therefore, it is necessary to keep the X-frame inclined platform clean. wheel, avoid wading).

3. Idler:

Idler is located at the front of the X-frame, and it consists of a guide wheel and a tension spring installed inside the X-frame. In the process of operation and walking, keep the guide wheel in the front, which can avoid abnormal wear of the chain rail, and the tension spring can also absorb the impact from the front pothole road to reduce wear and tear.

Idler is mainly used to control the loose, tight strength cylinder and grease nipple.

The loose, tightening spring assembly consists of a spring and a loose, tightening cylinder. tightening cylinder can adjust the tension of the track by injecting grease (butter). Many people do not care about this detail, but once it has problems, the consequences will be very serious. Seriously, because its position is relatively low and in a relatively static state, the piston rod is easily rusted in the cylinder barrel due to the long-term inactivity and the water vapor in the air, and the adjustment effect is invalid.

The tightening cylinder needs to be drained and filled with oil regularly. Drain the oil – loosen the grease nipple of the tightening cylinder at most one turn, and the butter will be squeezed out from the oil discharge port (because the internal pressure is particularly large, the operator must stand on the side. To prevent the grease nipple from being ejected and cause casualties), fill oil – tighten the grease nipple and use a grease gun to fill the grease until the track is tightened to the proper position.

4. Sprocket Rim

The Sprocket Rim is located at the rear of the X frame, the side guard of the walking motor, and the driving wheel is composed of a walking motor, a walking deceleration mechanism, and a walking gear ring. The travel motor obtains the hydraulic energy from the main pump to realize the rotation, and is decelerated by the travel deceleration mechanism, and then the crawler chain rail is driven by the travel ring gear installed on the casing to realize the excavator travel.

Details of the driving wheel, one side of the driving wheel must always be at the rear, because it is directly fixed on the X frame, and has no shock absorption function. The frame has adverse effects, and the X frame may have problems such as early cracking.

The travel motor guard plate can protect the motor, and its internal space will also store some soil and gravel, which will adversely affect the oil pipe of the travel motor. The moisture in the soil will corrode the joints of the oil pipe and the gravel. It will interfere with the oil pipe and cause related wear and oil leakage, so it is necessary to open the guard plate regularly to clean the dirt inside.

When replacing the final drive oil, park the excavator on a flat ground, turn the final drive until the oil drain port is at the bottom and perpendicular to the ground. Tighten the oil drain plug when refueling, and refuel from the top oil filler port. The oil can flow out.

5. Track Shoe

The Track Shoe is mainly composed of crawler shoes and chain links, and the track shoes are divided into reinforcing plates, standard plates and extension plates. Reinforcing plates are mainly used in mining conditions, standard plates are used in earthwork conditions, and lengthened plates are used in wetland conditions. The wear on the track shoes is the most serious in the mine. When walking, the gravel will sometimes get stuck in the gap between the two shoes. When it comes into contact with the ground, the two shoes will be squeezed, and the track shoes will easily bend. Deformation and long-term walking will also cause cracking problems at the bolts of the track shoes.

Track Shoe is in contact with the driving ring gear and is driven by the ring gear to rotate. Excessive tension of the track will cause early wear of the chain link, ring gear and idler pulley. The measurement of tension is to park the excavator on a flat ground, and use a straight long rod to place it on the track plate between the drive teeth or the guide wheel and the carrier wheel.

Measure the maximum vertical distance between the track shoe and the long rod, generally between 15-30mm; another method is to support one side of the track to measure the maximum vertical distance between the track shoe and the X frame, the value is generally 320 -340mm. Appropriate adjustments can be made according to specific working conditions. For example, in mines, wetland operations can be 20-30mm, 340-380mm, and sandy or snowy roads can be larger than 30, 380mm.

The above are the matters needing attention in the daily maintenance and operation of the excavator chassis. If you also have usage tips in daily work, you can log in to on our website:

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