Controllable factors

Elimination or reduction of controllable causes of wear is the main factor in increasing the resource of undercarriage assemblies. Since they can be controlled, these changes are chosen by the machine operator or the technology developer and play a major role in extending service life of the undercarriage. Correctly selected operation technology, strict adherence to the maintenance schedule and daily inspection will help to keep operating costs and machine downtime to a minimum.

TRACK TENSION

Ground sticking is the main cause of excessive track tension. Incorrect chain tension leads to accelerated wear of the drive system components. An overtightened track can shorten the service life of the track bushings and drive wheels by 2.5 to 3 times. It also leads to a decrease in performance (due to loss of traction) and increases fuel consumption.

SHOES IN USE

The main task of the shoes is to provide the machine's passability and good traction. Cross-country ability is the ability of a vehicle to move on soft ground or mud. Correct flotation is ensured when the shoe grousers fully penetrate the ground, and the shoes themselves should not sink below the surface of the ground. Shoes that are wider than necessary cause direct damage to the undercarriage. In fact, the wider the shoe, the higher the torque that will be transmitted to the undercarriage components each time the machine runs over bumps, as well as when operating on rocky ground. Since the pins and bushings of the track are the elements that are directly affected by the torque from the machine drive, and the reaction of the support follows from the shoes, these parts will be most affected. Also, the support rollers, drive wheels and idler wheels will suffer from the generated variable loads.

The main types of impact on the components of the undercarriage associated with the use of excessively wide shoes:

• Unproductive cornering resistance, which leads to a decrease in net engine power and an increase in fuel consumption. Turns lead to additional bending loads on the track parts and increased wear on the shoe edges.
• Structural problems of the shoes, including bending, cracking, breakage, etc.
• Increased wear on pins and bushings.
• Possibility of pins and bushings pressing-off from links.
• Reduced durability of track pivot joints. When wide shoes are used under shock loading conditions, bending forces increase, which leads to the "opening" of the sealing surfaces of the track parts. This can lead to a loss of lubrication, which in turn leads to internal wear of the joints and the stretching of the track pitch.
• Thread stretching or breakage of shoe bolts, followed by breakage of bolt holes in links and shoes, breakage and loss of shoes.
• Reduced life of links, roller flanges and idler wheel center flange.

OF THE INSTALLATION ALIGNMENT OF TRACK BOGIES AND UNDERCARRIAGE UNITS ON THEIR FRAME

• Accurate coaxial installation of the undercarriage components is extremely important to avoid their accelerated and unbalanced wear.
• The larger and heavier the machine and the higher the shock loads, the more likely temporary or permanent misalignment problems will occur.
• Misalignment of the bogie frame and sprocket will affect the wear of all links equally.
• Violation of parallelism between the bogie axis and the tractor axis will affect the wear of the rollers to a different extent, from the front to the rear, and the wear of the inner and outer sections of the treadmills and the outer flanges of the rollers.
• Any axial misalignment on the rollers, idlers and drive wheels increases wear on the treadmills of the links and flanges of the support and carrier rollers, the idler wheel and the sides of the drive wheel.
• The horizontal straightness of the bogie frame will not affect the track, but will affect the treadmills of the front and / or rear rollers compared to the center rollers.
• Carrier rollers can be used as a visual indicator of bogie frame alignment, but they are less reliable than track rollers.
• An overly tensioned track increases misalignment defects as it increases the stress on the interacting components.

ON-TIME UNDERCARRIAGE CLEANING AND CORRECT PARKING

These two factors are often overlooked, although they can significantly affect the lifespan of the undercarriage components. Cleaning the undercarriage as often as possible helps to remove sticking material, abrasives, and chemicals that will shorten the life of the undercarriage. This is especially important when working in low temperature environments. Adhered and frozen materials, abrasives and chemicals lead to excessive tension on the tracks, can interfere with the rotation of the carrier and track rollers, as well as the idler wheels, which leads to the formation of wear spots on the surface of their treadmills and failure of the seals. Cleaning also makes it easier to check for malfunctions and wear on the undercarriage components. The machine should always be parked on an even and flat surface, as when stopping on a slope for a long period, there is a static load on one side of the seals, as a result, their plastic deformation may occur, which in turn can lead to loss of lubricant from the rollers, idlers and lubricated track joints.