JT22 bulldozer traveling system includes three parts: frame (or frame), traveling device and suspension. The frame is the framework of the whole vehicle, which is used to install all the assemblies and components to make the whole vehicle a whole. The walking device is used to support the body and transform the driving torque and rotating motion transmitted by the power device to the driving wheel into the driving force and speed required for the vehicle to work and travel. The suspension is a connecting device that transmits force between the frame and the walking device.

Composition and function of JT22 bulldozer traveling device
The walking device of JT22 bulldozer is composed of walking frame, idler, track tensioner, carrier roller, roller, track assembly and drive wheel, etc. The left and right tracks are wrapped outside the four wheels, tensioned by the tensioner and directly contacted with the ground. The drive wheel drives the track to rotate around four kinds of wheels and does not roll directly on the ground. The guide roller is used to tension the track and guide it to correct winding. Several rollers roll on the track surface and transmit vertical load to the track. The carrier roller supports the upper half of the track to prevent it from sagging and reduce its vibration. The above four wheels and tensioning devices, except the driving wheels, are assembled on a wheel frame (namely, a bogie frame, also known as a crawler frame) to form a trolley. Each tracked vehicle has two trolleys, left and right. The weight of the whole vehicle is transmitted to the lower track through the platform frame and roller, so that the lower track is tightly pressed on the ground. When the drive wheel is driven by the final drive gear (driven gear), the gear tooth pulls the track, and the ground immediately produces a reaction force acting on the track, causing the carriage to move forward or backward relative to the ground, and the whole vehicle will move accordingly.
1. Track assembly. The track assembly includes track shoes, chain links, track pins, pin sleeves and other main parts. Each track is connected by dozens of track assemblies. Because it is in direct contact with the ground and bears all the weight and driving force of the body, it should have sufficient strength, rigidity and wear resistance. The track shoes used in the track assembly are generally equipped with shoes, which is to increase the adhesion of the track and make it not easy to slip. There are three types of foot stabs: single, double and triple. The loader uses double ribs.
2. Roller. The roller is one of the components with poor working conditions in the crawler traveling device. Therefore, reliable sealing device and lubricating device shall be provided. There are many types of roller structure, and the commonly used roller structure consists of shaft, wheel body, iron sleeve, floating oil seal and other main parts. The roller shaft adopts the middle shoulder type, and other parts are symmetrically arranged on both sides of the shoulder. Although this structure is more complex and less processable than the straight shaft type, it can withstand large axial force and impact load. Especially after the use of floating oil seal and bimetallic sleeve, the service life is greatly improved and the maintenance workload is simplified.
3. Idler. The function of the idler is to guide the running direction of the crawler walking device and ease the impact when the crawler moves forward. Like the roller, the idler also adopts the middle shoulder shaft, bimetallic sleeve and floating oil seal.
4. Carrier roller. The carrier roller is used to prevent the sag of the upper part of the track and the falling off of the track during walking. The carrier roller of the loader is generally cantilever mounted on the track frame. The structure of carrier roller is composed of main parts such as shaft, end cover, floating oil seal, carrier roller body and rolling bearing. The carrier roller is located at the upper part of the crawler frame and bears less load than the supporting roller. Dirt is not easy to enter and wear is less.
5. Drive wheel. The function of the drive wheel is to wind the track to make the loader walk. The drive wheel is installed at the rear of the track frame, and the working conditions are extremely heavy. There are many types of drive wheels, including the integral type, the ring gear insert type and the block gear type, which have advantages and disadvantages in use. In order to make the worn drive wheels still interchangeable and save raw materials as much as possible, the gear insert ring type is generally preferred. The number of teeth is mostly odd, which can improve the service life.
6. Track tensioning device. For example, when the crawler loader is walking and working, the articulated joint of each track section will be lengthened due to wear, which reduces the tension, increases the sag of the upper part of the track, jumps when walking, and even makes the track fall off, so the track tensioning device is required to tension. However, if the track tension is too tight, the pin shaft and pin sleeve will be subject to excessive stress and wear rapidly. Therefore, a proper tension must be adjusted. The track tensioner is connected with the idler and moves back and forth on the idler guide. There are many types of track tensioning devices, and the adjusting screw type and hydraulic type are widely used.