Showing papers on "Bellows published in 2015"

Dynamic Modeling of Bellows-Actuated Continuum Robots Using the Euler–Lagrange Formalism

Abstract: In the previous decade, multiple useful approaches for kinematic models of continuum manipulators were successfully developed. However, dynamic modeling approaches needed for fast simulations and the development of model-based controller design are not powerful enough yet—especially for spatial manipulators with multiple sections. Therefore, a practicable lumped mass model similar to common dynamic models of rigid-link manipulators is needed, which can be used for simulations and model-based control design. The model incorporates mechanical interconnections of parallel and serially connected bellows and uses constant curvature kinematics and its analytical derivatives to balance forces and energies in a global reference frame. The parameters of the resulting model are identified with measurements before the simulation results are experimentally validated. The obtained dynamic model can be used to both simulate the manipulator dynamics and calculate the inverse dynamics needed for model-based controller design or path planning.

Predictive model on the effect of restrictor on transfer function parameters on pneumatic control system

Abstract: ISSN: 2410-9649 Ukpaka / Chemistry International 2(3) (2016) 128-135 iscientic.org. 129 www.bosaljournals/chemint/ editorci@bosaljournals.com Certain performance characteristics such as fuel consumption, dynamic response and output stiffness can be compared for general types of pneumatic restrictor, such as piston cylinder 2000, Baranyi et al., 2004; Raven, 1987, Eckman 1958; Ogata, 19995). The final decision on the best type and design configuration for pneumatic restrictor can be made only in relation to the requirement of a particular application. The pneumatic restrictor has most often been of the piston cylinder type because of its how cost and simplicity (tabling et al., 1863). The pneumatic control power is converted to straight line reciprocating and rotary motions by pneumatic cylinders and pneumatic motors. The pneumatic control position servos system are used in numerous applications because of their ability to position loads with high dynamic response and to augment the force required moving the loads as revealed by some researchers (Humbird et al., 2010, Miroslaw and Ho, 2004). Investigation conducted by Clements and Len, 1985 revealed that pneumatic systems are also very reliable. The open literature surveyed showed a wide spectrum of new applications of pneumatics errors such as milling machines, roboties and advanced train suspension (Humbird, 2009, Carter et al., 2003, Savkovic-Stevanoivc, 2007, 2006; Zaddeh, 1994). The early detection of faults and other problems concerning the process are required. This detection is usually performed by using fault detection and diagnosis (FDD) methods implemented in a condition monitoring system. Condition-based maintenance as part of predictive maintenance is one of the tools used to increase productivity and reliability in the process industry. This is done by minimising unscheduled shutdowns and loss of product quality. Process plant performance and reliability cannot be improved without revealing deviations or problems by means of a condition monitoring system. This problem identification has to take place before problems become too serious in order to prevent major repairs and production breakdowns. Identification also has to take place online without disturbing the process, so as to maintain the efficiency of the plant. For this reason traditional offline performance tests are not feasible in real industrial applications these days. MATERIAL AND METHODS Pneumatic Proportional Control System Consider the pneumatic system shown in Fig. 1. It consists of several pneumatic components. The components, which can be easily identified, are: flapper nozzle, amplifier, air relay, bellows and springs feedback arrangement etc. The overall arrangement is known as a pneumatic proportional controller. It acts as a controller in a pneumatic system generating output pressure proportional to the displacement e, at one end of the link. The principle of operation is goes thus. The input to the system is a small linear displacement e and the output is pressure P. The input displacement may be caused by a small differential pressure to a pair of bellows, or by a small current driving an electromagnetic unit. There are two springs K2 and Kf those exert forces against the movements of the bellows A2 and A? For a positive displacement of e (towards right) will cause decrease of pressure in the flapper nozzle. This will cause an upward movement of the bellows A2 (decrease in y). Consequently the output pressure of the air relay will increase. The increase in output pressure will move the free end of the feedback bellows towards left, bringing in the gap between the flapper and nozzle to almost its original value. We will first develop the closed loop representation of the scheme and from there the input-output relationship will be worked out. The air is assumed to be impressible here. The effect of pressure on the bellow expansion without restriction is shown in figure 2a whereas its impact of pressure on the bellow expansion with restriction is show in figure 2b. The transfer function model formation A lot of commercial pneumatic controller designs are based on the flapper nozzle principle. It is a very sensitive system, such that a small movement will cause the controlled pressure to change. The device uses bellows as transducer for converting pneumatic pressure to mechanical notion. Assuming a force acting on the base simple bellow as shown in chapter two is AP where A is the effective cross-sectional area of the base, and the extension of the bellow is X. Therefore if the bellow is at rest PA = rX0 (1) For the restriction bellow arrangement the rate of flow of air f through the restrictor R is given by the relationship. R P P f 1   (2) assuming C to be the pneumatic capacitance of the bellow then R R P P dt CdP   (3) P P dt CdP R R   (4) Application of Laplace transformation ) 0 ( ) ( R R R P s SP dt dP   (5)

Torsional natural frequency tuning by means of pneumatic flexible shaft couplings

Abstract: This article deals with the use of pneumatic flexible shaft couplings as device for tuning torsional natural frequencies of mechanical systems. These couplings are using air bellows as flexible elements. Their torsional stiffness can be changed by air pressure change, the natural frequencies of whole mechanical system may be adjusted on desired value.

Design and Analysis of Hall Effect Probe-Based Pressure Transmitter Using Bellows as Sensor

Abstract: Bellows is an elastic-type pressure sensor used as a local indicator in industry. Transmission of bellows reading to a remote location in control room is very important in pressure measurement and control system in industry. In this paper, the design of a noncontact pressure transducer along with a transmitting unit using bellows as the primary sensing element and a Hall sensor as secondary sensing element has been described. The theoretical equations describing the operation of the proposed transducer and transmitter have been derived. The function of the transducer and transmitter has been experimentally tested and the experimental results are reported in the paper. Both transducer and transmitter characteristics have been found to be linear with good repeatability. The graphical abstract is shown in Fig. 1 . Fig. 1. Graphical abstract.

Embedded flexible spherical cross-polytopes with non-constant volumes

Abstract: We construct examples of embedded flexible cross-polytopes in the spheres of all dimensions. These examples are interesting from two points of view. First, in dimensions 4 and higher, they are the first examples of embedded flexible polyhedra. Notice that, in contrast to the spheres, in the Euclidean and Lobachevsky spaces of dimensions 4 and higher still no example of an embedded flexible polyhedron is known. Second, we show that the volumes of the constructed flexible cross-polytopes are nonconstant during the flexion. Hence these cross-polytopes give counterexamples to the Bellows Conjecture for spherical polyhedra. Earlier a counterexample to this conjecture was constructed only in dimension 3 (V.A. Alexandrov, 1997), and it was not embedded. For flexible polyhedra in spheres we suggest a weakening of the Bellows Conjecture, which we call the Modified Bellows Conjecture. We show that this conjecture holds for all flexible cross-polytopes of the simplest type, which includes our counterexamples to the ordinary Bellows Conjecture. Simultaneously, we obtain several geometric results on flexible cross-polytopes of the simplest type. In particular, we write down relations for the volumes of their faces of codimensions 1 and 2.

Experimental study on manufacturing metal bellows forming by water jet incremental forming

Abstract: Metal bellows have been widely used as expansion joints to absorb expansions and contractions in many engineering applications from the start of the century. In conventional metal bellows forming process, the main disadvantages are high cost of tooling required and lack of flexibility. To avoid the disadvantages, this paper presents a new metal bellows forming process using water jet incremental forming technology. The effect of some parameters in forming bellows is described in the paper. Meanwhile, because uniformity of thickness of metal bellows has great influence on its working life, the experimental research of the thickness distribution was carried out in the study. The feasibility of the process was validated by experiments.

Guide-wheel-free clinometer used for measuring displacement of deep part of landslide, and installation method thereof

Abstract: The invention discloses a guide-wheel-free clinometer used for measuring displacement of a deep part of a landslide, and an installation method thereof. The guide-wheel-free clinometers comprises a PVC pipe, a monitor case disposed above the pipe opening of the PVC pipe, and a plurality of detection nodes arranged in the PVC pipe. Every two adjacent detection nodes are connected to a bellows through a cable. Each detection node includes a main probe and four auxiliary probes. The main probe and the four auxiliary probes are sequentially connected in series through cables. The main probe and the adjacent auxiliary probes are connected through bellows, and every two adjacent auxiliary probes are connected through a bellows. A data acquisition module, a data transmission module and a power supply module are arranged in the monitor case. The data acquisition module is used for acquiring data of the main probe. The data transmission module is used for transmitting the data acquired by the data acquisition module to a remote data server center by means of a GPRS transmission network. The power supply module provides power for the data acquisition module and the data transmission module. On-site installation construction is convenient, the measurement is accurate, and automatic measuring and real-time dynamic monitoring can be achieved.

Numerical Investigations on Characteristics of Stresses in U-Shaped Metal Expansion Bellows

Abstract: Metal expansion bellows are a mechanical device for absorbing energy or displacement in structures. It is widely used to deal with vibrations, thermal expansion, and the angular, radial, and axial displacements of components. The main objective of this paper is to perform numerical analysis to find various characteristics of stresses in U-shaped metal expansion bellows as per the requirement of vendor and ASME standards. In this paper, extensive analytical and numerical study is carried out to calculate the different characteristics of stresses due to internal pressure varying from 1 MPa to 2 MPa in U-shaped bellows. Finite element analysis by using Ansys14 is performed to find the characteristics of U-shaped metal expansion bellows. Finally, the results of analytical analysis and finite element method (FEM) show a very good agreement. The results of this research work could be used as a basis for designing a new type of the metal bellows.

Corrosion Fatigue of Incoloy 825 Flare Gas Line Bellows of Expansion Joints

Abstract: Two out of eight expansion joints (bellows), which are part of flare gas line and made of Incoloy 825 material, failed during normal operation condition after 11 years in continuous service. The components of gas line including the expansion joint are exposed to aggressive environment where the burned gases consisting of CO2 and H2S pass through the 2205 duplex stainless steel piping system flared at a temperature of 60 °C and a pressure of 40 MPa. The external surfaces of the pipes were exposed to salt spray, winds, and sometimes sand storms. In addition to these, the failed expansion joints were subjected to continuous movement and/or vibration as a result of drilling operation, sea waves, etc. The received (failed) bellows showed numerous non-branched cracks over the circumference of the bellow, in addition to severe corrosion pits penetrating throughout the bellow’s wall thickness. Most of the pits and cracking were observed over the most stressed part of the bellows, which is the curved area. Detailed metallurgical investigation revealed that the expansion joint failed as a result of initiation of fatigue cracks at the corrosion pits that propagated through bellow’s circumference. Some of these cracks were found to extend up to 10–20 cm. Bellow’s curved design “stress concentration,” high chloride concentration on bellow’s metal surface, and high metal surface temperature (above 60 °C) in addition to the presence of bellows under continuous movement and/or vibration (fatigue type) may have led to localized corrosion and then fatigue cracking of the bellows.

Carrying platform elevating gear, reaction cavity, and plasma processing device

Abstract: The invention provides a carrying platform elevating gear, a reaction cavity, and a plasma processing device. A bracket driving source drives a shaft lifting bracket to do lifting motion. A bellows shaft passes through the shaft lifting bracket and is fixedly connected with the shaft lifting bracket, so as to do lifting motion with the shaft lifting bracket in a linear bearing, thereby realizing lifting motion of the carrying platform which is fixed on the bellows shaft. In the carrying platform elevating gear, a guiding mechanism is used to limit axial rotation of the bellows shaft in a lifting process. The bellows shaft passes through the linear bearing, a guiding shaft installing assembly, and a shaft lifting bracket in sequence. The guiding shaft installing assembly tightly holds the bellows shaft. The upper end of the guiding shaft is fixed on the cavity wall of the reaction cavity. The lower end of the guiding shaft passes through the guiding shaft installing assembly, so that the guiding shaft installing assembly does lifting motion with the shaft lifting bracket along the guiding shaft. The carrying platform elevating gear can limit rotation degree of freedom of a connecting rod, so as to ensure a carrying device from deflecting.

Air riding seal for a turbine

Abstract: An air riding seal between a rotor and a stator in a turbine of a gas turbine engine, where an annular piston is movable in an axial direction within a housing that extends from the stator, and a bellows is secured to the annular piston to form a flexible air passageway from a compressed air inlet through the annular piston and into a cushion cavity that forms an air riding seal between the annular piston and the rotor sealing surface. In another embodiment, a flexible seal secured to and extending from the annular piston forms a sealing surface between the annular piston chamber and the annular piston to provide a seal and allow for axial movement.

Non-contact vibrationless low-temperature solid interface thermal resistance testing arrangement

Abstract: The invention discloses a low-temperature solid interface thermal resistance testing arrangement. An upper end of a lower bellows and a lower end of an upper bellows are fixed in a sealed manner at an opening of an upper end of a vacuum cap; a seal cover covers the upper end of the upper bellows; the upper surface of the lower end of the lower bellows is connected to a lower surface of a bottom of a sample holder through a flexible cold guide structure; the lower end of the lower bellows contacts an upper surface of a cold head of a refrigerating machine; the upper end of the upper bellows, the upper end of the sample holder and the seal cover are tightly fixed to a vibration isolation support; and an enclosed space is formed by the upper bellows, the lower bellows and the seal cover, and is internally provided with a sample clamp, which is arranged at the bottom of the sample support and is used for mounting a sample to be detected. According to the structure in the invention, a vacuum environment can be formed in the enclosed space for the air in the enclosed space can be quickly pumped out; vacuum-pumping time and cooling time are reduced during sample replacement; and an experimental period is shortened. The upper end of the sample support is tightly connected to the vibration isolation support, and the bottom of the sample support is connected to the lower end of the lower bellows through the flexible cold guide structure, so that influence of cold head vibration on the sample support when the refrigerating machine works is avoided.

Steel band reinforcing polyethylene helical bellows

Abstract: The utility model discloses a steel band reinforcing polyethylene helical bellows, include: the inner tube, well pipe, its cover are established in the outside of inner tube, are equipped with along the circumferencial direction of inner tube between inner tube and the well pipe a plurality ofly parallelly each other to be wavy strengthening rib, outer tube, its cover are established in the outside of well pipe, and outer tube and well pipe are at a distance of certain distance, the spring assembly, it includes along a plurality of sub - spring assembly of length direction interval setting between well pipe and outer tube of well pipe, the utility model discloses set up the strengthening rib between inner tube and well pipe, effectively improve steel band reinforcing polyethylene helical bellows's intensity, set up the spring assembly between well pipe and outer tube, have fine buffering and restitution to the extrusion of external force, can effectively prevent steel band reinforcing polyethylene helical bellows and result in being out of shape because of the external force extrusion, especially bury when putting underground, prevent effectively that soil can produce the extrusion to steel band reinforcing polyethylene helical bellows on every side.

The Effects of Convolution Geometry and Boundary Condition on the Failure of Bellows

Abstract: Bellows have wide applications in automobile, aerospace, piping systems and industrial systems. An optimised shape for the bellows is expected to give good guidelines for practical design. Metallic bellows expansion joints are subject to displacement loading, this frequently results in cyclic strains. The effects of convolution geometry and boundary conditions on the failure of bellows are analysed in this study. Lateral deflection is considered as a boundary condition and a FEM solution for bellows is obtained. The stress distribution and the number of cycles to failure in the conditions of lateral deflection are obtained. Comparing results, the relation between the number of load cycles to failure and the flexible tube radius is obtained. In addition, the relation between stress and boundary conditions for the model in this study is also obtained.

Pressure compensator for subsea device

Abstract: A pressure compensator for providing pressure compensation for a chamber of a subsea device is provided. The pressure compensator has an enclosure with at least an outer wall. A first compensation chamber is provided inside the enclosure. A flow connection from the first compensation chamber towards the chamber of the subsea device is further provided. As second compensation chamber is provided inside the enclosure. First and second separating walls are arranged inside the enclosure. A first bellows portion of the first separating wall and a second bellows portion of the second separating wall are deformable to provide pressure compensation between the chamber of the subsea device and a second inner volume around which the second separating wall extends.

Automatic height compensating and co-planar leveling heat removal assembly for multi-chip packages

Abstract: Embodiments of the present disclosure may include a heat removal assembly that is to thermally couple with two or more dice of an electronic device. The heat removal assembly may include a bellows to automatically adjust a position of at least one surface of the heat removal assembly relative to another surface of the heat removal assembly. Other embodiments may be described and/or claimed.

Bellows is prevented leaking in vacuum

Abstract: The utility model relates to a bellows is prevented leaking in vacuum, including corrugated metal pipe body, corrugated metal pipe body is by corrugated metal outside of tubes pipe layer (1), corrugated metal pipe inner tube layer (2) and vacuum layer (7) that are located between the two constitute, corrugated metal outside of tubes pipe layer (1), corrugated metal manages inner tube layer (2), vacuum layer (7) constitute airtight cavity, install on the corrugated metal outside of tubes pipe layer (1) valve (3) and pressure sensor (4), valve (3), pressure sensor (4) are sealing connection corrugated metal outside of tubes pipe layer (1) respectively, straight section (10) tip welding of corrugated metal pipe body has turn -ups sleeve (6), turn -ups sleeve (6) peripheral cover is equipped with flange (5), the utility model discloses preventing leaking effectual, doing benefit to and carry fuel gas etc And need prevent the material that leaks, can keep the corrugated expansion joint to absorb the effect of vibration, and product life is long, the equipment maintenance is also comparatively convenient

Device is left and taken to midstream urine sample

Abstract: The utility model discloses a device is left and taken to midstream urine sample, include body, drainage tube and leave and take the pipe, be provided with the switch ball valve on the drainage tube, the upper end and the funnel of body are connected, the upper end of funnel is provided with the handle, the lower extreme and the storage urine bottle of body are connected, the funnel passes through the body and stores up urine bottle intercommunication, the bottle that stores up the urine bottle is scalable bellows, the upper end of storing up the urine bottle is connected with the joint seat, the lower extreme that stores up the urine bottle is connected with the base, the joint seat with be provided with nested pipe between the base The utility model discloses a device is left and taken to midstream urine sample sets up to scalable bellows through the bottle that will store up the urine bottle to can adjust the volume that stores up the urine bottle, can be accurately directly perceived leave and take the pipe with the midstream urine through switch ball valve, drainage tube collection, make things convenient for the patient simultaneously

Pneumatic detector assembly with bellows

Abstract: In one aspect, a pneumatic detector assembly is provided. The assembly includes a housing, a sensor tube, a contact pin, and at least one switch having a bellows operatively associated with the sensor tube and the contact pin. The bellows is configured to move into and out of contact with the contact pin based on a pressure in the sensor tube.

Design and analysis of cable-connected metallic bellows as Variable Buoyancy Modules

Abstract: Design of a variable buoyancy system with metallic bellows for underwater applications is presented here. Metallic bellow with a Linear Actuator is proposed as the Variable Buoyancy module. The metallic bellow is approximated as a cylinder and modelled mathematically to study the behavior of the module underwater. The response of the system at different initial orientation and the velocity of the system at different positive buoyancy are studied. The dynamics of the module, when anchored to an underwater platformand the motion characteristics of the module with various buoyancy levels are studied. Two similar modules are then cascaded one above the other and their performance is analyzed with alternative sequence of actuation.

Air supporting vibration filter structure of antipollution

Abstract: The utility model relates to an air supporting vibration filter structure of antipollution, including the filter vat, be equipped with the parallel filter of contact tube and polylith in the filter vat, the top outside of filter vat is equipped with the vibrator, and its inner chamber bottom is equipped with the fixed air supporting pipe of taking the gas pocket, and fixed air supporting pipe is connected with the air pump in the filter vat outside, the upper end of filter is rotated and is installed the gyro wheel, and the gyro wheel is connected with the cam cooperation, and the cam links firmly on the actuating lever, and the actuating lever tip stretches out the filter vat outward and install driving motor, to be passed through during the actuating lever rotation the elevating movement opposite direction of elevating movement, adjacent filter is to cam and gyro wheel drive filter, be provided with the unsteady air supporting pipe of taking the gas pocket about still in the filter vat, the air supporting pipe that floats runs through the filter and links firmly through adapter sleeve and filter, and the tip of the air supporting pipe that floats passes through bellows and intake -tube connection, and the intake pipe is vertical to be set up in the outside of filter vat and is connected with the air pump, and the lower extreme of intake pipe passes through bottom pipe and fixed air supporting union coupling

Stretch-proofing insulated cable anticorrosives

Abstract: The utility model discloses a stretch-proofing insulated cable anticorrosives, it includes the cable body, the cable body includes conductor, insulating layer, shielding layer and oversheath. Cable body inside is provided with many conductors, the conductor is crowded package one deck bellows outward, bellows and conductor constitution cable core, the outside closely crowded package one deck insulating layer of bellows, clearance part between bellows and the insulating layer is provided with the filler, just the clearance part is provided with many carbon fiber complex core sticks between bellows and the insulating layer, the insulating layer is crowded package one deck shielding layer outward, the fine polyester area of package glass, armor and inner sheath are closely crowded from inside to outside in proper order to the shielding layer, and the outer sheath is extruded out of the inner sheath. The utility model has the advantages of reasonable, the anticorrosive and long service life of structural design.

Lens defect automatic checkout device of grating modulation

Abstract: The utility model discloses a lens defect automatic checkout device of grating modulation, establish in camera bellows (13) lining including keeping apart detecting system, motion control system and light source system, isolation detecting system, motion control system establishes in the bottom of camera bellows (13), and motion control system establishes in one side of camera bellows (13), its characterized in that: grating (6) be fixed in sharp lead screw guide rail (5) on, plane backlight (10) parallel is fixed in by object plate (4) below and is connected with light source controller (11), main control unit (12) are controlled the motion control system through motion control card (9) realization The device carries out twice sampling through the method that removes the grating position to the lens image, through gray value to in the ming dynasty, the details in a play not acted out on stage, but told through dialogues image and form feature analysis, realizes classification, location and measurement to the lens defect, very big improvement lens test's rate of accuracy and efficiency

Chucking warped wafer with bellows

Abstract: A vacuum chuck has at least one suction assembly that pulls a wafer surface toward a chucking surface. The suction assembly may be used with a wafer that is warped. A suction force engages a pad of a suction assembly with the wafer surface and retracts a bellows of the suction assembly. As the bellows retracts and draws the wafer surface closer to the chucking surface, the suction force provided by the vacuum chuck can pull the wafer flat.

Bellows sealing end and cement-based material self-constriction measurement equipment using same

Abstract: The utility model provides a bellows sealing end and cement-based material self-constriction measurement equipment using the same. The bellow sealing end comprises lantern rings, sealing disks and rubber bands; the cement-based material self-constriction measurement equipment using the same comprises bolts, nuts, a bellows and a support, the structure is simple, the operation is simple and convenient, and the good technical support is provided for cement-based material self-constriction measurement tests.

External tunable damping rings for flexible coupling

Abstract: Damping rings (25) of suitable disclosed material are disposed exteriorly and between spaced apart convolutions (12, 13, 14, 15; 31, 32) of a bellows (21; 28) of a flexible coupling (10; 30). One, two or more damping rings (25) are oriented in a coupling (10; 30) between bellows convolutions (12, 13, 14, 15; 31, 32) and the convolutions (12, 13, 14, 15; 31, 32) adjacent a damping ring (25) extend radially outward of an outer periphery (25a) of the ring (25). Optional outer braids (40) are held radially outward of the damping rings (25).