Based on analysis of flow field of the rotary seal using sealing ring, mechanical models under the condition of full film friction and mixed film friction were established respectively. The influence of friction state...Based on analysis of flow field of the rotary seal using sealing ring, mechanical models under the condition of full film friction and mixed film friction were established respectively. The influence of friction state of the sealing ring on seal performance was also discussed. The relation between force characteristic and structural parameters of the sealing ring was analyzed. Analytical results indicate that friction state mainly depends on structural parameters of the sealing ring. The expression of calculating friction torque under the condition of mixed film friction was deduced. Experiment verification had been done. Experimental results agree with the deducing theoretical conclusions on the whole. It lays the foundation for design of new type of sealing ring used in composite transmission.展开更多
The metal sealing performance of subsea X-tree wellhead connectors is crucial for the safety and reliability of subsea X-trees. In order to establish the theoretical relation between metal sealing ring＇s contact stre...The metal sealing performance of subsea X-tree wellhead connectors is crucial for the safety and reliability of subsea X-trees. In order to establish the theoretical relation between metal sealing ring＇s contact stress and its structural parameters and working pressure, a mechanical analysis method for double-cone sealing of high pressure vessels is applied in analyzing the metal sealing ring under the condition of preload and operation. As a result, the formula of the unit sealing load for the metal sealing ring under operation with residual preload is shown in this paper, which ensures that the metal sealing ring has an excellent sealing effect and can prevent the metal sealing ring from yielding. Besides, while analyzing the sealing process of the metal sealing ring, the change rule of contact stress and working pressure is concluded here, putting forward that the structural parameters of the metal sealing ring are the major factors affecting the change rule. Finally, the analytical solution through theoretical analysis is compared with the simulation result through finite element analysis in a force feedback experiment, and both are consistent with each other, which fully verifies for the design and calculation theory on metal sealing ring＇s contact stress and its structural parameters and working pressure deduced in this paper. The proposed research will be treated as an applicable theory guiding the design of metal seal for subsea X-tree wellhead connectors.展开更多
Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability an...Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.展开更多
Large size mechanical seals are one of the most important components used in reactor coolant pumps.However,the hydrodynamic seal rings with wavy face are difficult to machine due to their high hardness and high form a...Large size mechanical seals are one of the most important components used in reactor coolant pumps.However,the hydrodynamic seal rings with wavy face are difficult to machine due to their high hardness and high form accuracy demand.In order to solve this difficult problem,a novel four-axis linkage grinding method using a cup wheel to process the hydrodynamic seal rings by line contact was proposed.A preliminary study indicates that the form error of the ground seal ring surface is extremely sensitive to different linkage relations of the four axes.By taking the center height of the cup wheel and the laws of motion along the X-axis,Z-axis,B-axis and C-axis as control variables,their effects on the principle form error of the ground surface are evaluated.Six implementation strategies are proposed to reach lower principle form errors.It is found that the minimal principle form error is only 9.64 nm and hence its influence on the ground seal ring shape can be neglected in designing an ultra-precision grinding machine.In addition,the results indicate that the position accuracy of the X-axis at the microscale is acceptable no matter which implementation strategy is selected.This study is expected to serve as a theoretical basis for design and development of the four-axis ultra-precision grinding machine.展开更多
It is urgent to carry out detailed research on storage performance of rubber sealing ring to get the criterion for its storage life. This paper acquires material ageing regularity by theoretical analysis and experimen...It is urgent to carry out detailed research on storage performance of rubber sealing ring to get the criterion for its storage life. This paper acquires material ageing regularity by theoretical analysis and experimental confirmation. On this condition, failure mode and failure criterion of typical sealing structure is studied, and the failure mechanism is found. Thus by analyzing the stress distribution, the relationship between ageing state and sealing condition is established. Rationalization proposal is put forward and storage life of sealing ring is evaluated. The research mentionedabove has special reference to the design of sealing structures and can provide reference for prolonging their service life.展开更多
基金Sponsored by the Ministerial Level Foundation (404020806)
文摘Based on analysis of flow field of the rotary seal using sealing ring, mechanical models under the condition of full film friction and mixed film friction were established respectively. The influence of friction state of the sealing ring on seal performance was also discussed. The relation between force characteristic and structural parameters of the sealing ring was analyzed. Analytical results indicate that friction state mainly depends on structural parameters of the sealing ring. The expression of calculating friction torque under the condition of mixed film friction was deduced. Experiment verification had been done. Experimental results agree with the deducing theoretical conclusions on the whole. It lays the foundation for design of new type of sealing ring used in composite transmission.
基金Supported by National Hi-tech Research and Development Program of China(863 Program,Grant No.2012AA09A205)
文摘The metal sealing performance of subsea X-tree wellhead connectors is crucial for the safety and reliability of subsea X-trees. In order to establish the theoretical relation between metal sealing ring＇s contact stress and its structural parameters and working pressure, a mechanical analysis method for double-cone sealing of high pressure vessels is applied in analyzing the metal sealing ring under the condition of preload and operation. As a result, the formula of the unit sealing load for the metal sealing ring under operation with residual preload is shown in this paper, which ensures that the metal sealing ring has an excellent sealing effect and can prevent the metal sealing ring from yielding. Besides, while analyzing the sealing process of the metal sealing ring, the change rule of contact stress and working pressure is concluded here, putting forward that the structural parameters of the metal sealing ring are the major factors affecting the change rule. Finally, the analytical solution through theoretical analysis is compared with the simulation result through finite element analysis in a force feedback experiment, and both are consistent with each other, which fully verifies for the design and calculation theory on metal sealing ring＇s contact stress and its structural parameters and working pressure deduced in this paper. The proposed research will be treated as an applicable theory guiding the design of metal seal for subsea X-tree wellhead connectors.
基金supported by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.Q2023J012).
文摘Purpose–The brake pipe system was an essential braking component of the railway freight trains,but the existing E-type sealing rings had problems such as insufficient low-temperature resistance,poor heat stability and short service life.To address these issues,low-phenyl silicone rubber was prepared and tested,and the finite element analysis and experimental studies on the sealing performance of its sealing rings were carried out.Design/methodology/approach–The low-temperature resistance and thermal stability of the prepared lowphenyl silicone rubber were studied using low-temperature tensile testing,differential scanning calorimetry,dynamic thermomechanical analysis and thermogravimetric analysis.The sealing performance of the lowphenyl silicone rubber sealing ring was studied by using finite element analysis software abaqus and experiments.Findings–The prepared low-phenyl silicone rubber sealing ring possessed excellent low-temperature resistance and thermal stability.According to the finite element analysis results,the finish of the flange sealing surface and groove outer edge should be ensured,and extrusion damage should be avoided.The sealing rings were more susceptible to damage in high compression ratio and/or low-temperature environments.When the sealing effect was ensured,a small compression ratio should be selected,and rubbers with hardness and elasticity less affected by temperature should be selected.The prepared low-phenyl silicone rubber sealing ring had zero leakage at both room temperature(RT)and�508C.Originality/value–The innovation of this study is that it provides valuable data and experience for the future development of the sealing rings used in the brake pipe flange joints of the railway freight cars in China.
基金supported by the National Basic Research and Development Program(Grant No.2009CB724306)
文摘Large size mechanical seals are one of the most important components used in reactor coolant pumps.However,the hydrodynamic seal rings with wavy face are difficult to machine due to their high hardness and high form accuracy demand.In order to solve this difficult problem,a novel four-axis linkage grinding method using a cup wheel to process the hydrodynamic seal rings by line contact was proposed.A preliminary study indicates that the form error of the ground seal ring surface is extremely sensitive to different linkage relations of the four axes.By taking the center height of the cup wheel and the laws of motion along the X-axis,Z-axis,B-axis and C-axis as control variables,their effects on the principle form error of the ground surface are evaluated.Six implementation strategies are proposed to reach lower principle form errors.It is found that the minimal principle form error is only 9.64 nm and hence its influence on the ground seal ring shape can be neglected in designing an ultra-precision grinding machine.In addition,the results indicate that the position accuracy of the X-axis at the microscale is acceptable no matter which implementation strategy is selected.This study is expected to serve as a theoretical basis for design and development of the four-axis ultra-precision grinding machine.
文摘It is urgent to carry out detailed research on storage performance of rubber sealing ring to get the criterion for its storage life. This paper acquires material ageing regularity by theoretical analysis and experimental confirmation. On this condition, failure mode and failure criterion of typical sealing structure is studied, and the failure mechanism is found. Thus by analyzing the stress distribution, the relationship between ageing state and sealing condition is established. Rationalization proposal is put forward and storage life of sealing ring is evaluated. The research mentionedabove has special reference to the design of sealing structures and can provide reference for prolonging their service life.
