Pdf this article presents the analytic models of four types of flexure hinges elliptic, circular, parabolic. This paper designs and analyzes a new kind of flexure hinge obtained by using a topology opti mization. Each of these hinge types is described by a parameterized geometric model. Flexi hinge is a compact, versatile, easytoinstall device which requires no maintenance, offers indefinite life and is resistant to detrimental environmental conditions.
This article presents the comparison of various compliancestiffness equations of circular flexure hinges with fea results. In order to accurately calculate the above parameters, this article. The limitation of these equations at different t r r is the radius and t is the neck thickness ratios are revealed. Pdf comparison of circular flexure hinge compliance. Three flexure hinges for compliant mechanism designs based. The microgripper is designed, and a comparison study on stress and displacement is done by varying the hinge parameters such as the hinge radius, web thickness, position of flexure hinge, and radius of curvature of hinges. A flexure bearing is a bearing which allows motion by bending a load element. Modeling and analysis of deformation on a flexure bearing in linear compressor vennapusa v sivareddy1 corresponding author. This paper presents the dimensionless empirical equations and graph expressions of three flexure hinges for compliant mechanism designs. Firstly, asymmetrical right circular flexure hinge is presented and the structure factor is introduced in the paper according to the size of the cutting arc radius of both sides of right circular flexure hinge.
A flexible multibody modeling approach is used for efficient modeling. Us4694703a circumferentially oriented flexure suspension. There are several examples on the wikipedia page, but i would add in addition to those examples that probably the most common flexure bearing would be the. Pdf a new generalized model for elliptical arc flexure. On modeling the bending stiffness of thin semicircular. Pdf modeling and design of flexure hingebased compliant. Design of a flexural hinge mechanism for turbo slits. An improved modeling approach for circular flexure hinges with application to geometry optimization. A simple compliance modeling method for flexure hinges. This paper establishes four models of ushaped flexure hinges with different notch shapes and structure parameters, and presents the closeform compliance equations for the four structure types of. The inplane and outofplane stiffnesses of the flexure hinges are developed. We also plan to offer a variety of quartz flexure accelerometers ranging in size, weight and application usage. Culpepperb a lawrence livermore national laboratory, l223 7000 east avenue, livermore, ca 94551, usa b mit department of mechanical engineering, room 35209, 77 massachusetts avenue, cambridge, ma 029, usa a r t.
The paper introduces a new class of twoaxis flexure hinges with axiallycollocated and symmetric notches as an alternative to the existing flexure. See microsystem design by senturia for more information. Leaf springs are an example of a flexure system with one compliant degree of freedom. Abstract this article presents the comparison of various compliancestiffness equations of circular flexure hinges with fea results. Flexures will produce these motions without any friction or hysteresis down to the subnanometer level, and they never need lubrication. It is a parallel mechanism of high stiffness, which can offer 6 degrees of freedom, with its size controlled under 100 mm x. Flexure bearings are often part of compliant mechanisms. Dec 07, 2017 the flexure hinge of claim 15 wherein the cross section of the thin spot defined by the intersection of the direction x and direction z plane at the thin spot has the shape of one or more rectangles. Pdf material coherent flexure hinges allow a specific geometrical design of. The flexures may be broken when removing them from the laser cutter. The flexure hinge of claim 15 wherein the cross section areas spaced apart along the direction z comprise a plurality of identical geometric. Modeling and design of flexure hingebased compliant. A twostage topological optimum design for monolithic. Torsional stiffness of several variable rectangular cross.
The flexure hinge has the highest accuracy, when the bending point is located in the centre of the hinge 7. Pdf analysis and design of symmetric notch flexure hinges. A precision stage employing a lever mechanism and flexure hinges is analyzed theoretically, with bending in the lever considered. The paper introduces a common twoaxis ellipticalarcfilleted flexure hinge that is generated by two different ellipticalarcfilleted cutout profiles and that provides some new hinge types. Review of circular flexure hinge design equations and. Multiaxis nano positioning flexure stage using magnetically. A design method for flexurebased com pliant mechanisms. This invention relates to improvements in a flexure joint for connecting a pair of members for relative angular displacement about a hinge axis, the joint comprising a pair of leaf springs which cross each other and merge at their ends with the members.
Design of flexure hinges provides practical answers and directions to the needs of efficiently designing, analyzing, and optimizing devices that include flexure hinges. For combining the advantages of different notch contours. Flexure stages may also be bought from the following vendors. Optimal design of a flexurehinge precision stage with a. Forthesecalculations,thegeometryofthe3d hinge is modelled using a 2d quarter of the model, shown in fig. Important material properties for various applications of flexure hinges and torsion suspensions. A compliant mechanism gains its mobility fully or partially from the compliance of its elastically deformable parts rather than from conventional joints. Dec 27, 2002 flexure hinges hold several advantages over classical rotation joints, including no friction losses, no need for lubrication, no hysteresis, compactness, capacity to be utilized in smallscale applications, ease of fabrication, virtually no assembly, and no required maintenance. Therefore, a general closedform solution for flexure hinges of different profiles that incorporates the profile selection and parameter design will be of great benefit to the hinge design. As a kind of important flexible joint, twoaxis flexure hinges can realize inplane and outofplane motions and can be used for constructing flexure based spatial compliant mechanisms. Due to many advantages, in particular the smooth and repeatable motion, monolithic mechanisms with notch flexure hinges are state of the art in numerous.
Large stroke performance optimization of spatial flexure. The aspect of this deformation effect on the hinge compliances is beyond the scope of this paper. Jan 23, 2010 in this paper, a new twodimensional, compliant, monolithic piezoactuated microgripper using flexure hinges is reported. Flexure hinge has been widely used in high precision micropositioning mechanism and the most common type is right circular flexure hinge. He studied the stress distribution at all flexure joints, modal analysis and the workspace. The optimal solution of the butterfly flexure hinge shows the least decrease in the supporting stiffnesses of the evaluated hinges. In this paper, a new twodimensional, compliant, monolithic piezoactuated microgripper using flexure hinges is reported. The simplest form of flexural hinge is the cantilever flexure. Pdf the influence of asymmetric flexure hinges on the axis of.
Flexure joint, particularly for connecting a gyroscope to its. Numerous studies have been made for the design of flexure hinges and compliant mechanism 2327. Flexure hinge, stiffness, rotational precision, hinge index. Design of flexure hinge mechanism for dynamic yaw control of fpd lithography stage dahoon ahn1, hyunchang kim1, daegab gweon1 sunho lee2, woohyuck choi2, sungtaek baek2 sanghoon lee2 junkyu park2 1department of mechanical engineering korea advanced institute of science and technology. Pdf an improved modeling approach for circular flexure. Hinge swaging swaging is a slight offset of the hinge leaf at the barrel which permits the leaves to come closer together when parallel hinges are slightly less in width when both leaves are not swaged. Combining the results of chen 16, the correct stiffness. This study investigates a number of commonly used flexure hinges to determine a flexure hinge. Combining equations 24 results in displacement components u. Hinge swaging swaging is a slight offset of the hinge leaf at the barrel which permits the leaves to come closer together when parallel hinges are.
During the optimization, constraints are applied to the. Flexure bearings serve much of the same function as conventional bearings or hinges in applications which require angular compliance. The paper focuses on the development of design equations that can accurately predict the behavior of such stages especially the lost motion due to hinge stretching. Fliptop on a shampoo bottle piezobeams on a scanning tunneling microscope because of the bending stresses created in the flexure. Highly accurate, even after a lifetime of cycling, flexihinges offer the optimum solution for many of todays engineering problems. If you have a user account, you will need to reset your password the next time you login. The length of travel of this very accurate motion is, however, quite limited.
It contains readytouse plots and simple equations describing several flexure types for the professional that needs quick solutions to current applications. The developed stage makes use of magnetically preloaded pzt actuators and a ball contact mechanism to avoid the crosstalk among the axes. The stiffness and rotational precision of flexure hinges are the most crucial factors to be considered during the flexure hinges design. Pdf modeling and design of a twoaxis elliptical notch. Relations between design parameters and magnification ratio, and the optimal values for the parameters to achieve a longer stage displacement are presented. Many kinds of flexure profiles were proposed during the past decade.
A special flexure hinge is adopted to actuate the single stage in three axes at the same time. When the hinge thickness is divided into n parts, the symmetrical prismatic joint is composed of n flexure hinges, and the thickness of each flexure hinge is tn. Flexure hinges have been used in many engineering areas where high precision and sensitivity are required. Design and experiment of a 3dof parallel micromechanism utilizing flexure hinges byungju yi, member, ieee, goo bong chung, heung yeol na, whee kuk kim, member, ieee, and il hong suh, senior member, ieee abstract flexure hinge has been commonly used as a substitute for mechanical joints in the design of micropositioning mecha. Design and analysis of a highaccuracy flexure hinge. Static deformation modeling and analysis of flexure hinges. Deshmukh3 1,2 department of mechanical engineering, sinhgad institute of technology, lonavala. Pdf analysis and design of a spherical micromechanism. For the fembased investigations, the variable hinge height k x of all flexure hinges. Leaf springs are commonly used in vehicle suspensions. For the fembased investigations, the variable hinge height k x of all flexure hinges of the compliant h. Later cornerfilleted flexure hinges were designed and analyzed by lobontiu et al. What id like to do now is rotate the two halves along that flexure hinge.
Lever mechanisms are usually used to enlarge output displacements in precision stages. The stage considered here is composed of flexure hinges, piezoelectric actuators and their peripherals. The measure of performance is defined by the first unwanted natural frequency, which is closely related to the supporting stiffnesses. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. A design method for flexurebased com pliant mechanisms on. Proposed magnetically actuated soft capsule endoscope masce. Based on the limitations of these design equations, a guideline for selecting the most accurate equations for hinge design calculations are presented. The flexural hinge has a welldefined rotation axis normally defined geometrically by the axis of the reference.
Synthesis of precision serial flexure systems using freedom. A twoaxis, monolithic, flexure hinge suspension system for an accelerometer or gyroscope has first, second and third cylindrical portions which are slightly axially spaced from each other along a common axis and are connected by pairs of flexible hinges therebetween. A flexure bearing is a category of flexure which is engineered to be compliant in one or more angular degrees of freedom. Torsional stiffness of several variable rectangular crosssection. Based on the limitations of these design equations, a guideline for selecting the most accurate equations for hinge design. Large stroke performance optimization of spatial flexure hinges. This paper establishes four models of ushaped flexure hinges with different notch shapes and structure parameters, and presents the closeform compliance equations for. Design of flexure hinge mechanism for dynamic yaw control of fpd lithography stage dahoon ahn1, hyunchang kim1, daegab gweon1 sunho lee2, woohyuck choi2, sungtaek baek2 sanghoon lee2 junkyu park2.
A flexure can be used to reproduce almost perfect linear or rotary motion or a combination of both. Flexure hinges are materially coherent connections between two bodies or body segments with at least one relative motion due to mostly elastic deformation 5. So its something that provides support, but also allows motion by bending a component as opposed to sliding. The actual part is much more complicated, including various facets, curves, and cuts, so im not sure how to rotate the sections to open up the part. Analysis and design of symmetric notch flexure hinges. A onepiece 3d printed flexure translation stage for opensource microscopy james p. Design of flexure hinges provides practical answers to the present and future needs of efficient design, analysis, and optimization of devices that incorporate flexure hinges. Deformation effect outside flexure hinge geometry figure was provided by schotborgh.
Each pair of flexible hinges is mutually perpendicular to another pair of flexible hinges and is also perpendicular to. Design and experiment of a 3dof parallel micromechanism. Due to many advantages, in particular the smooth and repeatable motion, monolithic mechanisms with notch flexure hinges are state of the art in numerous precision engineering applications with required positioning accuracies in the. The rotational precision, denoted by the midpoint stiffness, is derived for the purpose of optimized geometric design. Flexures me en 7960 precision machine design topic 12 me en 7960 precision machine design flexures 122 general flexural bearings are widely used in practice application range from. Calculation on rotation stiffness of asymmetrical right. The loads and the corresponding small deformations at t. Investigation of circular flexural hinge used in compliant. Therefore, a symmetric circular flexure hinge is suitable for ultra precision positioning system.
A general approach for the design of flexurehinge type lever mechanisms that are commonly used in the design of translational micropositioning stages is presented in this paper. Design and performance optimization of large stroke. A cantilever flexure is a single leaf or notched flexure rigidly clamped between the two sections of a mechanism with one fixed and one free to rotate. As an important part of the joule balance system, the twoaxis elliptical notch flexure hinge tenfh which typically consists of two singleaxis elliptical notch flexure hinges was studied. The paper introduces a new class of twoaxis flexure hinges with axiallycollocated and symmetric notches as an alternative to the existing flexure designs with seriallydisposed notches. A cantilever is a flexural beam rigidly supported at one end only. Preferred for their simplicity, as they can be included as a feature in a single piece of material as in a tic tac boxs lid. The significance of this effect are currently being investigated and will be revealed in near future. This paper designs and analyzes a new kind of flexure hinge obtained by. A continuously description regarding this part is given in the next paragraph. A onepiece 3d printed flexure translation stage for open.
Force balanced quartz flexure accelerometers jewell instruments. Analysis and design of a spherical micromechanism with flexure hinges. A compact 2dof piezoelectricdriven platform based on z. For mems, the fabrication process is complex and errorprone. A symmetric circular flexure hinge has the bending point in the centre of the hinge. Mar 01, 2011 the split is 5mm long, leaving a 1mm flexure hinge that connects the two halves, so that the part opens up like two jaws. An improved modeling approach for circular flexure hinges with application to geometry.
The results shows that the elliptical flexural hinge has less stress for the similar displacement, the corner filleted flexural hinge was the most accurate in the sense of motion. Simplified optimum design of flexure hinges we measure the locations of hinge like rotational axis obtained by the firststage topology. Analytical solution of stiffness for a cornerfillet leaf. Pdf a generic compliance modeling method for twoaxis. A general concept of flexural hinge is composed by three elements. The obtained optimal hinge designs are validated with a finite element model and show good agreement. Flexure hinges and torsion suspensions are devices which connect or transmit load between two. Request pdf a simple compliance modeling method for flexure hinges various types of flexure hinges have been introduced and implemented in a variety of. Calculation of the zshaped flexure hinge flexure hinges are widely exploited in piezoelectricdriven platforms, due to their unique superiorities. The circular hinge the dimensionless design graph for the circular. Unlike the conventional rotational joint which is constructed by different rigid parts, the. Design and analysis of a highaccuracy flexure hinge aip publishing. Modeling of flexurehinge type lever mechanisms sciencedirect. This novel flexure based mechanism is capable of delivering planar motion with three degrees of freedom 3dof.
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