The causes of abnormal wear of forklift tires

Under certain load and driving conditions, the tires of a forklift have an appropriate tire pressure. When the tire pressure is lower than the standard value during driving, the radial deformation of the tires increases, causing excessive deflection on both sides. As a result, the tire crown touches the ground on both sides, the inner wall of the tire side is compressed, the outer wall of the tire side is stretched, and the cord inside the tire body undergoes significant deformation and alternating stress. Periodic compression deformation will accelerate the fatigue damage of the cord, increase the relative sliding between the cord layer of the tire and the tire and the ground, increase the heat generated by friction, cause the tire temperature to rise sharply, reduce the tensile strength of the rubber, loosen the cord and cause local delamination. When encountering obstacles and being impacted, a blowout will occur. The uneven pressure on the tread causes severe wear on the shoulder of the tire, resulting in a "bridge effect", and the tread appears toothed or wavy. The concave parts of tire treads are prone to embedding nails and stones on the road, causing mechanical damage. The rolling resistance of the carcass increases, and the fuel consumption rises. Tests show that when the tire pressure is 20% to 25% lower than the standard value, fuel consumption increases by 20% accordingly. When driving with tire pressure higher than the standard value, the center of the tire crown touches the ground, reducing the contact area between the tire and the road surface, increasing the load per unit area, and intensifying the wear in the middle of the tire crown. When the cord of a tire is overly stretched, the stress on the cord of the tire body increases, the fatigue process of the cord accelerates, causing the cord to break and resulting in an early blowout of the tire.

Under certain loads and tire pressures, as the vehicle speed increases, the deformation frequency of the tires, the vibration of the tire body, and the circumferential and lateral twisting deformation of the tires (forming rest waves) also increase accordingly. The heat generated per unit time due to friction increases, and the working performance of the tires declines. In severe cases, the fabric layer may break and the tread may peel off, accelerating the wear and damage of the tires.

Under a certain tire pressure, overloading the tire will increase its deflection deformation, and the stress on the cord fabric and cord will increase. This can easily lead to the cord breaking, loosening and delamination of the cord fabric at the tire wall. The force on the cord of the tire body will exceed the design allowable stress and the ground contact pressure of the tire, generating more heat, raising the temperature of the tire body and reducing its load-bearing capacity. At the same time, due to the contact between the tire shoulder and the ground, wear occurs. Especially when encountering obstacles, even a small stone can cause the tire crown to burst. Practical experience has shown that when driving on turns and uneven roads, if the tire load exceeds 20%, the driving range will be shortened by 35%. When it exceeds 50%, shorten by 59%. When it exceeds 100%, shorten it by more than 80%.

④ Road conditions also have a significant impact on the service life of tires. They affect the friction between the tires and the ground as well as the dynamic loads the tires are subjected to.

⑤ High temperatures will reduce the tensile strength, elongation and hardness of rubber, decrease the adhesion strength between rubber and cord, and also accelerate the aging of rubber. For tires exposed to high temperatures, especially those that have aged, when they skid sideways or roll over obstacles, it is very easy for the tire crown tread to tear. Due to the aging of the sidewall rubber causing cracks and severe deformation of the sidewall leading to the separation of the cord from the rubber in the carcass layer, once a local area of the tire is subjected to sudden load, a blowout is very likely to occur.

When tires are corroded by grease, acidic or alkaline substances and exposed to high temperatures for a long time, their physical and chemical properties will change, their load-carrying capacity will be greatly reduced, and they are also highly prone to blowouts during use. In addition, tires that have been corroded by oil may experience blocky peeling of the air seal layer, small areas of rubber detachment at the tire orifice, and the separation of the tire cord from the rubber. Since the patch cannot be compatible with oil-impregnated rubber, even if the damage wound on the tire is very small, there is no possibility of repair.

Due to the different loads distributed to the front and rear axles, the distinct working characteristics of the drive wheels and steering wheels, and the varying road conditions, the wear conditions of each tire are inconsistent. If tires of the same factory, size, structure, grade and pattern are not replaced on both sides of the same axle, it will accelerate the wear of the tires.

During use, if proper matching and regular rotation are not paid attention to, resulting in uneven load on the tires, it will also accelerate tire wear.