Talking about the choice of lubrication method of sliding bearing
High-power motors use liquid lubricant sliding bearings. The peripheral speed of the high-power high-speed motor journal is 20-80 meters per second; the loss of the sliding bearing is 80-120 watts per square centimeter, and the local loss of the oil mold can reach several hundred watts per square centimeter. Therefore, in the design of the sliding bearing of high-power motor, when selecting the sliding bearing structure type and selecting the sliding bearing parameters, it is necessary to pay attention to reduce the sliding bearing loss, strengthen the cooling, reduce the temperature rise, and improve the safety and life of the sliding bearing.
After the high-power motor is subjected to a small external transient disturbance in operation, it should have the ability to recover from normal operation to normal operation, that is, static stability capability; and the load sudden disturbance in the process of generating faults or driven mechanical equipment in the power supply system In this case, it should have the ability to maintain its stable safe operation, that is, dynamic stability. This requires the designer to carefully consider the above factors to ensure static and dynamic stability in the overall design, especially in the design of the sliding bearing, especially to avoid the self-oscillation phenomenon of the sliding bearing oil film.
In the operation of the motor, the sliding bearing requires the spindle journal to support the oil film formed by the liquid lubricating oil injected into the bearing clearance, and maintain sufficient lubricant film presence and oil film renewal.
Sliding bearing lubrication
Sliding bearing lubrication is available in three ways: self-lubricating, forced cooling and compound lubrication. The bearing pad clearance design of the sliding bearing of modern high-power motors is guaranteed by the machining process. The design uses a compound lubrication method, and it is necessary to provide a lubricating oil supply system for forced circulation cooling outside the sliding bearing of the motor.
The self-lubricating method, commonly known as oil ring lubrication, is a relatively traditional lubrication method and has been widely used in low-speed high-power motors. The utility model is characterized in that the lubrication system is free from external influences, the structure is simple, the operation is safe and reliable, and the maintenance workload is small, but the oil ring lubrication relies on the self-weight rotation of the oil ring to inject the lubricating oil into the sliding bearing bush, and thus is not suitable for the high speed motor. application.
A self-cooling oil circulating seat type sliding bearing with an oil-reducing disc structure in the early stage has been widely used in modern motor products because it has been reinjected into a new concept. Although this structure is self-lubricating, it is widely used. For high speed and high power motors. The self-cooling oil circulating seat type sliding bearing with oil-lifting disc structure is not affected by external factors, and is especially suitable for high-speed motors. The structural feature is that an oil lifting disc is assembled on the bearing end stage of the motor main shaft. When the electric motor rotates, the oil lifting disc lifts the lubricating oil to the oil guiding groove, and the oil guiding groove injects the lubricating oil into the cylindrical bearing bearing. A self-cooling oil circulation system is formed. The cylindrical bearing shoe is a split-type uniaxial thrust surface alloy tile structure.
The oil guiding groove is a grooved opening of the end of the double groove steel casting after processing and the oil lifting disc is a sliding fit, and a balance pulsing rod with a diameter of 8 mm is welded on the upper plane of the oil guiding groove, and is placed flat. Upper slide bearing cap on the support frame. In the upper part of the upper sliding bearing cover, a window is opened and an upper gland is provided, and a balance pressure finger is mounted on the upper gland to keep the oil guiding groove and the oil lifting plate cooperatively sliding and balanced. The upper sliding bearing cover and the lower sliding bearing seat constitute a self-cooling oil circulating seat type sliding bearing with an oil lifting disc structure. The structure design is reasonable, the volume is small, and the appearance is beautiful. It is a modern energy-saving seat type sliding bearing.
Reprinted from the network