The passenger car door system is a complex subsystem in rail vehicles, which bears heavy loads. The requirements for the door system are very high, such as high reliability and long maintenance intervals. The operating period of the door system is stipulated by the bus manufacturer. Depending on the model, the number of door system openings may exceed 2.5 million. The opening process of the door system usually includes the rotation and unhooking of the door and the linear opening movement. Rotational movement is achieved through maintenance-free joint bearing and rod end bearing models. Sometimes radial plug-in ball bearings with flange seats are also used. In linear motion, the door system is guided by linear ball bearings, guide rail systems or special rollers. These bearings are sample standard bearings or specially modified parts, for example, optimized outer ring/rail contact pressure. Rod end bearings can be treated with anti-corrosion, and internal and external left-handed or right-handed threads can be processed. As a component of a passenger car, this linear motion must be reliable. The linear ball bearing runs smoothly and has a long life. It is very effective when used here; if necessary, it also has the ability to self-align. Depending on the bearing type, the ability to compensate for misalignment can reach ±40'. Due to the small size and low radial section height, linear ball bearings require less space. According to customer needs, bearings are usually sealed with their own, if necessary, corrosion-resistant design is also provided. The shaft on which the linear ball bearing is installed must be high-precision and can be made into an anti-corrosion design; the hollow shaft is light in weight, which is especially suitable. Customers can request the length and function of the guide rail according to the actual assembly conditions. The guide rail system is suitable for the occasions of heavy load, high operation and position accuracy requirements and good rigidity. If necessary, products with general sealing and lubrication and NA special coating are available. The door system bearings used in trucks such as sliding door trucks (HIBBNS, ...) and dump trucks (FALNS, ...) need to give priority to the requirements of sturdiness, long life and low maintenance. The bearings used for the door closing mechanism, displacement device, guide and torque support, and hinge rod include bolt-type rollers, rollers, needle bearings and joint bearings. The function of the coupler joint bearing coupler is to realize the connection between the locomotive and the freight car and the freight car and the freight car and transfer the traction force. Some special designs, such as the closed coupler, not only transmit traction, but also bear the compression force and weight, such as the closed coupler used in the SGGRSS intermodal truck. According to UIC577 or EN12663 standards, the load transmitted by the coupler reaches 2 000 kN. ELGES joint bearings have more than 30 years of application experience in this field. The steel/steel contact joint bearings that require maintenance were first used, but nowadays, maintenance-free joint bearings with strong load-bearing capacity, long life, and ELGOGLIDE® sliding layer are widely used. This long-term development is to achieve the needs of vehicle operators to reduce vehicle maintenance costs and parking time.