Design And Reliability Analysis Of The Shrink Fit Fixture In The Manufacturing Process Of Seal Ring Using The Pre-deformation Plane Lapping Method

Reactor coolant pumps has been hailed as the heart of a nuclear reactor, nuclear power plant is one of the core equipment. Nuclear main pump, the cooling medium radioactive, therefore, the mechanical seal performance for the safe operation of nuclear power plants is very important to the whole. Mechanical seals are the key technical decisions nuclear main pump working properly, but the mechanical seal assembly are easily damaged during the operation, once more than the specified amount of leakage is likely to cause serious accidents of life and property, to social development and human health great threat. So far, China’s main pump, especially the main pump seal is also entirely dependent on imports, nuclear main pump seal mechanism is still not deep enough, did not form a complete product design and production systems, supply side is also limited, these factors seriously affected the progress and development of China’s nuclear power industry. Only increase the nuclear main pump seal mechanism of deep research and innovative design, in order to accelerate the pace of localization of nuclear power equipment.Pre-deformation plane lapping method (abbreviated as Pre-deformation method) is a processing method of complex curved surface, and it is an alternative low-cost processing method of circumferential seal ring without relying on high precision machining tool. Thermal shrink fit fixture is one of the method to realize pre-deformation of end face of seal ring. Here, thermal shrink fit fixture is designed for the sealing ring with tapered face and sealing ring with wavy face. Based on the finite element analysis model of assembly process, the effects of structure parameters and its accuracy on the deformation are analyzed. Finally, the possibility of the manufacturing of sealing ring with tapered face using the pre-deformation plane lapping method is verified theoretically and experimentally.In this paper, the main nuclear hydrostatic pump type with a cone angle of the sealing ring and sealing ring with wavy face, for example, the design of the heat seal ring mounted fixtures, and finite element analysis and experimental verification, the main work and results for:the establishment of a hot-mounted fixtures and two-dimensional finite element model of the seal ring, and the model was solved mesh and loading of pre-deformation simulation results; results showed that the amount of interference tooth load and pre-deformation dip a significant linear relationship, which can be adjusted by the amount of interference on the seal faces is optimized; analysis of the load angle of the tooth thickness and pre-deformation relationship, find the tooth thickness of 3～5 mm, the tooth thickness was negatively correlated with the inclination, the tooth thickness of 1～3 mm, less impact on the inclination of the tooth thickness. This is because the tooth thickness is small, the teeth of the seal ring loading force is very small, so there is no obvious relationship between the size and inclination.Analysis of Sealing ring with wavy face through the assembly process is limited to a pre-mounted thermal deformation of the fixture element analysis to study the fixture main parameters influence of pre-deformation, deformation law gives the seal ring, found to affect the upper teeth on the waveform larger, lower teeth on the wave length of the zone inhibition. Analysis of the pre-deformation processing errors influence, given the correspondence between the fixture between the accuracy and precision of pre-deformation found consistency errors affect discrete integrated sealing rings and clamps on the wave of the very large, totally under ideal conditions cannot be used had a linear relationship between the amount of interference and distortion to explain. By sealing ring performance analysis, found that the use has compared the performance of the ideal face shape deformation method for processing the seal ring are some differences, it is necessary to further the goal to seal performance to optimize the structure of the fixture design.Finally, the possibility of the manufacturing of sealing ring with tapered face using the pre-deformation plane lapping method is verified theoretically and experimentally.