The sealing performance of the automobile water pump shaft bearing has a certain degree of difficulty

Because the diesel engine, which is the key to the car, is moving towards a high-power and high-efficiency direction, higher characteristics are clearly set for the bearing of the automobile water pump shaft. Such as having higher heat resistance, greater bearing capacity and excellent sealing characteristics. The automobile water pump shaft bearing is a new type of rolling bearing developed and designed in order to better integrate into the requirements. It is essentially a double-supported shaft system with a simplified structure. The two-supported rolling bearing has no inner throwing ring. The dovetail guide rail of the turning body is immediately made on the shaft. The outer ring of the two-supported rolling bearing is made into a whole, and the throwing ring The two sides of the shaft are sealed with hydraulic seals to form a component of the coupling.

Under the same standard of bearing capacity, its axial specification is lower than that of general types of rolling bearings; under the same standard of axial specification, its bearing capacity exceeds that of general types of rolling bearings. Because of its good rigidity, rotation, simple structure, and convenient assembly and disassembly, many western capitalist countries such as the United Kingdom, Japan, France, etc. have long selected shaft-connected rolling bearings of this type. At this stage, part of my country's automobile water pump shafts and bearings have not yet selected such excellent structural forms, but still use two deep groove ball bearings and shafts to form a shaft system. This type of form has many construction stages, complicated installation process, high efficiency and low rigidity, and has been replaced by excellent centrifugal water pump shaft and rolling bearings. The various centrifugal water pump shaft and rolling bearings developed and designed by RTL have been widely used in domestic vehicles and introduced vehicles.

The centrifugal water pump is composed of a centrifugal water pump casing, a shaft-connected rolling bearing, an exhaust valve, a centrifugal impeller, a cooling fan and a transmission equipment. The shaft-connected rolling bearing is a key component of the centrifugal water pump. Because the speed of the centrifugal water pump is relatively high, the speed ratio of the general centrifugal water pump is 6000r/min, and the speed ratio of the high-speed centrifugal water pump is higher than 9000r/min. Therefore, it is stipulated that the shaft connected rolling bearing has a higher bearing capacity, so that the centrifugal water pump can be considered. The stipulation of the service life under a certain speed ratio. The indoor space of the centrifugal water pump is limited, the total area of heat removal is small, and the standard is extreme in operation. Therefore, the rolling bearing of the shaft should be able to maintain all normal operations under high temperature, and the bearing capacity of the rolling bearing should not be reduced. The tightness of the rolling bearing has a certain degree of difficulty, and the credibility and performance of its tightness will immediately endanger the applicability of the centrifugal water pump. All in all, the bearing capacity, backlash and sealing characteristics of shaft-connected rolling bearings are the three key performance parameters that endanger the performance indicators of centrifugal water pumps.

Bearing steel balls and roller bearings of automobile water pump shaft bearings are generally manufactured from high chromium 45 steel, and the raw materials for the shaft and outside are made of nitriding steel or high chromium 45 steel. The shaft’s raw material is made of nitriding No. 45 steel. The strength of the shaft dovetail rail is generally 60-64HRC; the strength of the shaft produced by high chromium No. 45 steel is generally 58-62HRC; the strength of bearing steel balls and roller bearings is 61 -65HRC; the outer strength is generally 60-64HRC.