Springs Flra Hajdu B 406 hajdflsze hu Content

Springs Flóra Hajdu B 406 hajdfl@sze. hu

Content • Role of springs • Types of springs 2021. 02. 19. Hajdu Flóra

Springs • Role of springs • Flexible coupling • Energy storage • Force or torque limitation • Force or torque measurement • Damping vibrations • Size balancing closing element 2021. 02. 19. Hajdu Flóra

Springs • Springs may be classified into 3 groups according to their application. • Controlled Action Springs: have a well-defined function, or a constant range of action for each cycle of operation. Examples are valve, die, and switch springs. • Variable-Action Springs: have a changing range of action because of the variable conditions imposed upon them. Examples are suspension, clutch, and cushion springs. • Static Springs: exert a comparatively constant pressure or tension between parts. Examples are packing or bearing pressure, antirattle, and seal springs. 2021. 02. 19. Hajdu Flóra

Springs The type or name of a spring is determined by characteristics such as function, Source: C. Jensen, J. D. Helsel, D. R. Short: shape of material, application, or design. Engineering Drawing&Design 2021. 02. 19. Hajdu Flóra

Spring characteristics • Deformation – force diagram Spring stiffness 2021. 02. 19. Hajdu Flóra

Spring nomenclature 2021. 02. 19. Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Hajdu Flóra

Compression springs • A compression spring is an open-coiled helical spring that offers resistance to a compressive force • Compression sping ends • Plain open ends are produced by straight cutoff with no reduction of helix angle. The spring should be guided on a rod or in a hole to operate satisfactorily. • Ground open ends are produced by parallel grinding of open-end coil springs. Advantages of this type of end are improved stability and a larger number of total coils. • Plain closed ends are produced with a straight cutoff and with reduction of helix angle to obtain closed-end coils, resulting in a more stable spring. • Ground closed ends are produced by parallel grinding of closed-end coil springs, resulting in maximum stability. Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design 2021. 02. 19. Hajdu Flóra

Compression springs 2021. 02. 19. Hajdu Flóra

Compression springs na=4, 5 nt=6, 5 na=4 nt=6 2021. 02. 19. Hajdu Flóra

Technical drawing of a compression spring L 0: free length Ln: length of the spring corresponding to maximum allowable load L 1, L 2: lengths corresponding to F 1, F 2 forces 2021. 02. 19. Hajdu Flóra

Extension springs Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design • An extension spring is a closecoiled, helical spring that offers resistance to a pulling force. • It is made from round or square wire • The end of an extension spring is usually the most highly stressed part. Thus, proper consideration should be given to its selection. • Different types of ends can be used on the same type of spring. 2021. 02. 19. Hajdu Flóra

Extension springs 2021. 02. 19. Hajdu Flóra

Torsion springs Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design • Springs exerting pressure along a path that is a circular arc, or in other words, providing a torque (turning action) • usually a helical spring of round, square, or rectangular wire, loaded by torque. • The variation in ends used is almost limitless • A torsion bar spring is a relatively straight bar anchored at one end, on which a torque may be exerted at the other end, thus tending to twist or rotate it about its axis. 2021. 02. 19. Hajdu Flóra

Torsion springs 2021. 02. 19. Hajdu Flóra

Power springs (spiral spring) • A fiat coil spring, also known as a clock or motor spring, consists of a strip of tempered steel wound on an arbor and usually confined in a case or drum. 2021. 02. 19. Hajdu Flóra

Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Flat springs • Flat springs are made of flat material formed in such a manner as to apply force in the desired direction when deflected in the opposite direction. • Leaf springs • Belleville springs 2021. 02. 19. Hajdu Flóra

Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Leaf springs • A leaf spring is composed of a series of flat springs nested together and arranged to provide approximately uniform distribution of stress throughout its length. Springs may be used in multiple arrangements 2021. 02. 19. Hajdu Flóra

Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Belleville springs • Belleville springs are washershaped made in the form of a short, truntacted cone. May be assembled • in series to accomodate greater deflections • In parallel to resist greater forces • In combination of series and parallel 2021. 02. 19. Hajdu Flóra

Beleville springs 2021. 02. 19. Hajdu Flóra

Rubber springs • Application: vehicle industry • Advantage • high deformability • different shapes can be easily achieved, • high energy storage. • Disadvantage: • the oxygen in the air causes the rubber to age rapidly, • it freezes in a cold environment, it becomes fragile, • Mineral oil dissolves 2021. 02. 19. Hajdu Flóra

Rubber springs 2021. 02. 19. Hajdu Flóra

Rubber springs 2021. 02. 19. Hajdu Flóra

Air springs • Hydropneumatic system • The spherical spring element is separated by a diaphragm • the space between the membrane and the piston is filled with oil • Push rod is connected with a lever to the wheel. • By changing the oil charge, the chassis can be held at a constant height regardless of the load. • Automatic - the oil flow is controlled by the shift lever controlled by the wheel arm. • The constant oil pressure required to control the system is provided by an air-cushioned oil battery between the oil pump and the control pump. 2021. 02. 19. Hajdu Flóra

Spring clips • Spring clips perform multiple functions and eliminate the handling of several small parts -> reduce assembly costs. • generally self-retaining requiring only a flange, panel edge, or mounting hole to clip to. • light -duty fasteners and serve the same function as small bolts and nuts, self-tapping screws, clamps, spot welding, and formed retaining plates. • Dart-Type Spring Clips have hips to engage within panel or component holes. The top of arms of the fastener can be formed in any shape to perform unlimited fastening functions. • Stud Receiver Clips There are three basic types push-ons, tubular types, and self-threading fasteners. All are designed to make attachments to unthreaded studs, rivets, pins, or rods of metal or plastic. • Cable, Wire, and Tube Clips: These fasteners incorporate self-retaining elements for engaging panel holes or mounting on panel edges and flanges. Spring-clip cable, wire, and tubing fasteners are frontmounting devices, requiring no access to the back of the panel. • Spring Molding Clips: These are formed with legs that hold the clips to a panel and arms that positively engage the flanges of various sizes and shapes of trim molding and pull the molding tightly to the attaching panel • U-, 5 -, and C-Shaped Spring Clips The fastening function is accomplished by using inward compressive spring force to secure assembly components or provide self-retention after installation. 2021. 02. 19. Hajdu Flóra

Spring clips 2021. 02. 19. Source: C. Jensen, J. D. Helsel, D. R. Short: Engineering Drawing&Design Hajdu Flóra

Summary • Spring types • Next week: Welded, soldered, glued and riveted connections

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