As a green mode of transportation, rail transit vehicles aligns with the country's major strategy--carbon neutrality,which contributes to environmental protection, high efficiency and energy saving. With its rapid development, a variety of fasteners in rail transit play a vital role in ensuring the safe and stable operation of trains.
Rail transit fasteners refer to special fasteners used to fix and connect various components of rails. There are various types of fasteners according to different application scenarios and needs, which can be divided into bolts, nuts, rivets, pins, etc. They ensure the stable connection of components of the train.
In addition to welding and riveting, the connection mode of rail transit structural parts mainly adopts threaded connection, which not only meets the necessary functions of trainoperation, but also ensures the interchangeability requirements of important components. Due to the particularity of the structure, the heavier equipment such as the transmission, brake cylinder, and water tank on the rail
are installed on the chassis using high-strength bolts.
The features of rail transit fasteners areas follows:
A. High Strength & Reliability:
Rail transit fasteners are subject to enormous operating loads and impact forces, so they must have high strength and reliability to ensure that the train remains stable in long-term operation.
B. Abrasion & Corrosion Resistance:
Rail transit fasteners need to work in avariety of complex environments, so they need to have good wear and corrosion resistance to prolong their service life.
C. Security:
The fasteners must comply with relevant safety standards to ensure that they will not fall off or break in an emergency, ensuring the safety of passengers.When selecting the right fasteners for rail transit,the application scenario and train requirements should be taken into account: For example, rail transit vehicles have large vibration and shock loads during operation, and a large number of anti-loosening measures need to be applied, such as lock washers and lock nuts.There are often tapered embossed washers,double-stack lock washers,two-layer elastic washers, etc. Most of the locking washers are applied to elastic friction anti-loosening, while the double-stack lock washer adopts the principle of structural anti-loosening, which can be selected according to different installation occasions. Lock nuts are divided into all-metal ones and non-metallic insert ones.All-metal lock nuts generally use the type of nut deformation and anti-loosening through the type of grooving or extrusion thread deformation. Cavity is made on the top surface of the non-metallic insert nut, and a nylon ring is installed, the inner diameter of the nylon ring is smaller than the middle diameter of the thread. As a result, the friction between the threads is increased through the extrusion deformation during the installation of the nylon ring.
Considering the ease of maintenance, rail transit fasteners that are easy to install and remove for routine maintenance and overhaul should be chosen. At the same time, it should be noted that the
selected rail transit fasteners should be compatible with other parts of the train and will not have adverse effects.
