Papers by Keyword: Bellows

Abstract: Bellows are a cylindrical shell with a corrugated part, widely used in aviation engineering as a movable sealing element to balance pressure and temperature differences, which ensure continuous and accurate system operation. The use of bellows expansion joints provides reliable and effective protection of pipelines from static and dynamic loads arising from deformations and vibration. Welded-edge bellows are a popular choice for regulating and controlling fuel supply in aircraft devices. The ability of the compensator to perceive deformations is determined by its assigned operating time, which describes how many cycles, and with what amplitude, the bellows compensator perceives without damage. A method for stamping bellows from tubular billets by using magnetic-pulse field in rigid dies, including sequential shaping of corrugations by distributing the internal magnetic pressure with axial movement of the free end of a tubular billet, characterized in that the material of the tubular billet for shaping corrugations is selected in accordance with its relative elongation.

Abstract: Titanium alloy bellows has advantages of light weight, excellent mechanical property, good heat resistance and corrosion resistance, etc. But the cold formability of titanium alloy is poor, so it is difficult to manufacture titanium alloy bellows by traditional mechanical forming and hydroforming. In this paper, current assisted superplastic forming technology was used to process titanium alloy bellows, which could overcome some shortcomings of traditional superplastic forming effectively, such as slow heating rate, high energy loss and low production efficiency. And titanium alloy bellows formed by this technology is of good quality with uniform wall thickness, light oxidation.

Abstract: Austenitic stainless steel AISI 316L is used for components of cryogenic engine in satellite launch vehicles due to its better mechanical properties at low temperatures. In one such application, AISI 316L stainless steel bellows are used in electro-pneumatic command valve of a cryogenic engine. This valve employs a hydro-formed bellow of 0.14mm thickness as an actuator element. When one of the electro-pneumatic command valve was vibrated without pressure, crack was noticed at the inner diameter of the bellow. Detailed metallurgical analysis indicated that the cracking to be due to fatigue.

Abstract: Springback has an important influence on the forming quality of thin-walled stainless bellows hydroforming. By developing a FE model, the stress distribution is investigated and springback characteristics of two specification bellows are addressed. The results show that: (1) For tube Φ26×0.5, the maximum circumferential tensile/compressive stresses decrease by 32% and 29.1% after springback, respectively. The maximum longitudinal tensile/compressive stresses decrease by 51.8% and 39.6%, respectively. (2) Three indices are proposed to describe the bellow profile change after springback, namely, radial displacement of crown point; axial displacement of inner point; maximum convolution width. (3) For tube Φ26×0.1, after springback, the inward shrinkage of crown point increases by 0.7%, the bellow axial elongation is 0.76mm, the maximum convolution width increases by 30.3%.

Abstract: The article describes the technology of making thin-walled components and elastic by additive technology SLS using a polyamide powder PA 2200. The characteristics of the selected elements and the results of their strength tests are presented. The research focuses on the anisotropy of the materials in the various models. Printing processes were investigated on surfaces perpendicular and parallel to the axis of the model. Based on measurements of deformation, coefficients of elasticity, and the influence of selected parameters of the printing process, the accuracy of tested elements were determined. Comparing results of the research indicated that there is a significant influence of direction and printing process parameters on elastic properties. Research can be helpful in the future in the design process of elastic and thin-walled components such as springs and bellows.

Abstract: The article contains the results of studies concerning the effects of selected parameters of the manufacturing process of elastic bellows on their elastic properties and strength. Bellows models were made using additive technology SLS selective laser sintering, in which the material used to construct models was a polyamide PA 2200. Bellows printing process proceeded in a surface parallel to the axis of the bellows and in a surface perpendicular to it. Based on measurements of deformation coefficients of elasticity of bellows were determined, also the measure of the maximum axial force exerted by the bellows while loading the internal pressure was carried out. Comparing the measurement results a significant effect of process parameters on the flexible properties of elastic bellows and their resistance to internal pressure were determined.

Abstract: The article considers the analysis of the bellows fatigue strength carried out using the Ansys software package. The results of the research into the fatigue crack life and fatigue safety factor of a bellow valve are given.The reliability evaluation of the bellow valve working under the high-frequency load has been given by the authors.

Abstract: The paper deals with a design and simulations of segment for hyper-redundant manipulator. In the paper 6-DOF manipulator segment, which consists of pneumatic and electromagnetic actuators, is designed. CAD model of the segment is introduced and basic parts are described. The basic motion is reached by pneumatic actuator which works through the rubber bellows and it utilizes their expansion properties. Main focus of the study besides segment design is analysis of rubber bellows. From this reason FEM analysis is done in software SolidWorks. In the conclusion the results are discussed.

Abstract: Bellows generally operate as pressure transducers, based on elastic deformation of their undulations, but presents a higher interest as actuators. After a short presentation of the actuators based on elastic / inflatable elements, some structural schemes of bellows - based actuating systems are given, FEM analysis is emphasized and initial prototypes are described.

Abstract: The article contains the result of studies on the effects of selected geometrical parameters of elastic bellows on their elastic properties. Bellows models were produced with using additive technology, selective laser sintering SLS, where the material used to build models was polyamide PA 2200. Based on the measurements of elastic deformation coefficients of each models bellows were determined. Comparing the results of the measurements there was found a significant effect of the thickness, number of corrugations and their length on the value of the coefficient of elasticity.