What are the bearing lubrication methods for new energy vehicles?
January 11, 2022
As the core component of electric vehicles, the drive motor requires high reliability, high power density, wide high efficiency area, wide speed regulation range, and strong overload capability. As a precision part, the bearing itself is the key core of the drive motor. The motor needs high-performance bearings to ensure it. Grease is one of the key factors affecting bearing life. Lubricating grease is composed of Base Oil, thickener, and additives. The choice of grease should be determined according to the operating conditions of the bearing.
Nine commonly used lubrication methods for bearings: Manual lubricating oil When it is found that the lubricating oil of the bearing is insufficient, it is the most primitive method to use an oiler to supply oil in a timely manner. This method is difficult to maintain a certain amount of oil, and there is a greater risk of forgetting to refuel due to negligence. It is usually only used in occasions of light load, low speed or intermittent exercise. It is best to install a dust cover or a ball valve on the oil filling hole, and use felt, cotton, wool, etc. as the filter device. Drop point lubrication A roughly fixed amount of lubricating oil is supplied from the container through the hole, needle, valve, etc. The most classic is the drip cup. The amount of dripping oil varies significantly with the viscosity of the lubricating oil, the bearing clearance and the position of the oil supply hole. Used for light-load and medium-load bearings with a peripheral speed of less than 4～5m/s. Oil ring lubrication Can only be used for the lubrication method of the horizontal shaft. The ring that is hung on the shaft and can rotate brings the lubricating oil from the oil sump to the bearing. Suitable for medium-speed and high-speed bearings with shaft diameter greater than 50mm. The oil ring is preferably seamless. When the bearing width-to-diameter ratio is less than 2, only one oil ring can be used, otherwise two oil rings are required. Oil rope lubrication The lubricating oil in the oil cup is led to the bearing by the capillary action and siphon action of the wick, which is used for light-load and medium-load bearings with a peripheral speed of less than 4~5m/s. The wick has a filtering effect Oil pad lubrication Use the capillary action of the oil cushion to apply the lubricating oil in the oil pool to the surface of the shaft diameter. This method can keep the friction surface clean, but dust will also block the pores and cause insufficient oil supply. The oil supply of oil pad lubrication is usually only 1/20 of oil lubrication. Oil bath lubrication A lubrication method in which a part of the bearing is immersed in lubricating oil. It is suitable for the lubrication of low and medium speed bearings. Part of the bearing is immersed in the oil groove. The lubricating oil is picked up by the rotating bearing parts and then flows back to the oil groove. The oil level should be slightly lower than the center of the lowest rolling element. Splash lubrication The lubricating oil splashed by the flapping of the rotating parts in the oil tank is supplied to the bearing, which is suitable for the bearing of higher speed. Spray lubrication The lubrication method of spraying lubricating oil on the friction surface is suitable for high-speed bearings. Pressure lubrication Relying on the pressure of the lubricating pump to supply oil to the bearing, and recovering the lubricating oil flowing from the bearing to the oil pool for recycling is the most stable and stable lubrication method. It is suitable for high-speed, heavy-duty, and important sliding bearings.
