Brake shoes and brake pads are friction plates used for deceleration, braking and braking of various vehicles and mechanical equipment. Just use different equipment and have different names, such as: train brake shoes, mine hoist brake shoes, automobile brake pads, industrial and agricultural machinery friction discs, used in different places, and each has its own national standard. Brake linings are disc type and drum type.
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The brakes are required during the operation of the train. The braking parts that directly rub the wheels to stop the train are brake shoes. A shoe pad made of cast iron or other material holds the wheel tread when braking and stops the wheel by friction.
In this process, the braking device converts the huge kinetic energy into thermal energy dissipated in the atmosphere. The quality of this braking effect depends mainly on the ability to dissipate frictional heat energy. When using this braking method, the friction area of the brake shoe is small, and most of the thermal load is borne by the wheel. The higher the train speed, the greater the thermal load on the wheels during braking. If the brake shoe is made of cast iron, the brake shoe can be melted by the temperature; even if a more advanced synthetic brake shoe is used, the temperature will be as high as 400-450°C. When the wheel tread temperature increases to a certain extent, it will make the tread wear, crack or peel, affecting the service life also affect traffic safety. It can be seen that traditional brake shoe brakes cannot adapt to the needs of high-speed trains.
Brake tile categories: cast iron brake shoes and synthetic brake shoes. Cast iron brake shoes are divided into grey cast iron brake shoes, medium phosphorus brake shoes, high-phosphorus iron brake shoes and alloy cast iron brake shoes. Synthetic brake shoes, according to its basic composition, are divided into synthetic resin-based brake shoes and rubber-based brake shoes. According to the friction coefficient, it can be divided into high friction coefficient composite brake shoes and low friction coefficient composite brake shoes. Medium-phosphorus cast iron brake shoes, high-phosphorus cast iron brake shoes and low friction synthetic brake shoes are general brake shoes.
The effect of synthetic brake shoes on the wheels:
1. Hot cracking ----- Due to poor contact between the brake shoe and the wheel, local overheating occurs on the wheel tread, forming hot spots, and thermal cracking may occur in individual cases.
2. Groove wear of the wheel - Use synthetic brake shoes in the section with frequent braking to increase the wheel temperature. Due to the local friction and thermal expansion of the synthetic friction material, the wheel tread exhibits groove wear. The higher the temperature, the more easily the wear develops on the outside of the wheel tread, and the groove wear is caused by the lateral friction of the brake shoe.
3, the concave wheel wear ------ synthetic brake shoe in winter snow area, this kind of wear will occur. This is due to the fact that water is introduced into the friction surface of the brake shoe.
