Numerical Analysis And Experimental Research On Controllable Mechanical Seal Of Stern Shaft

Ordinary mechanical seal can always work steadily in the designed situation. Once the condition or environment is changed, high face load may be produced, which will result in serious wear, shorter service life and final failure; or else, the thickness of the film is so large that there is severe leak and the seal failure. The paper studies the important principle of mechanical seal characteristics in variable conditions by both numerical and experiment analysis methods, which could be the theoretical basis for mechanical seal design of the same types.In the design of the controllable mechanical seal device, temperature rising, which is controlled through compression and extension of spring changing closure effect of the sealing ring face, is considered to be the feedback signal for the mechanical seal control system. The paper analyses the friction of the sealing ring with Friction Theory, describes the basic principle of selection of the seal ring material and physical characteristics and application of general materials and studies how the sealing properties and service life are influenced by the shrink range of mounted rotating seal ring.In the analysis of mechanical seal field coupling of temperature and stress, properties of heat conduction and contact are given and the block model of sealing ring is built up. According to ANSYS software solutions in accordance with the characteristics of related issues, contact elements are set up at sealing ring contact face, and large heat conduct coefficient is determined ,which makes the friction heat generated in the process of working transfer preferentially between the contact faces, and calculation precision of heat flow density is improved by iterative cycle. At the same time, the border of heat convection is analyzed using the classical principle of heat transfer theory and the heat transfer coefficient of corresponding border is computed using classical formula. Distribution of temperature field and stress field, relative axial distortion in different environment are computed and their influence factors are also analyzed.In the mechanical seal experiment, temperature, leakage and friction torque of the sealing ring face are measured in screw shaft controllable mechanical seal plant and the results are compared with those of theoretical calculation, which indicates that the theoretical calculations coincide with those of the experimental results, therefore the mathematical model for temperature field and stress field is turned out to be correct.In the mechanical seal friction experiment, first of all, axial stress of the seal device is analyzed, and the possible friction status and mechanism of the ring face at the angle of tribology. Then friction coefficient and seal characteristics criterion are used to divide the friction states, the application of which is verified experimentally.