Coil spring

A coil spring, also known as a helical spring, is a mechanical device which is typically used to store energy and subsequently release it, to absorb shock, or to maintain a force between contacting surfaces. They are made of an elastic material formed into the shape of a helixwhich returns to its natural length when unloaded. Under tension or compression, the material (wire) of a coil spring undergoes torsion. The spring characteristics therefore depend on the shear modulus, not Young's Modulus. A coil spring may also be used as a torsion spring: in this case the spring as a whole is subjected to torsion about its helical axis. The material of the spring is thereby subjected to a bending moment, either reducing or increasing the helical radius. In this mode, it is the Young's Modulus of the material that determines the spring characteristics. Metal coil springs are made by winding a wire around a shaped former - a cylinder is used to form cylindrical coil springs. Coil springs for vehicles are typically made of hardened steel. A machine called an auto-coiler takes spring wire that has been heated so it can easily be shaped. It is then fed onto a lathe that has a metal rod with the desired coil spring size. The machine takes the wire and guides it onto the spinning rod as well as pushing it across the rod to form multiple coils. The spring is then ejected from the machine and an operator will put it in oil to cool off. The spring is then tempered to lose the brittleness from being cooled. The coil size and strength can be controlled by the lathe rod size and material used. Different alloys are used to get certain characteristic’s out of the spring, such as stiffness, dampening and strength  A compression coil spring A tension coil spring A selection of conical coil springs Oxy-cut spring showing deformation due to loss of tempering in adjacent turn Spring Rate Spring rate is the measurement of how much a coil spring can hold until it compresses 1 inch. The spring rate is normally specified by the manufacture. If a Spring has a rate of 100 then the spring would compress 1 inch with 100lbs of load.  Variants Volute spring suspension on an M4 Sherman tank Types of coil spring are: Tension/extension coil springs, designed to resist stretching. They usually have a hook or eye form at each end for attachment. Compression coil springs, designed to resist being compressed. A typical use for compression coil springs is in car suspension systems. Volute springs are...

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Transverse leaf spring and solid axle front suspension of early Ford cars

Transverse leaf spring and solid axle front suspension of early Ford cars is a type of automotive front suspension that has been most common in early Ford Motor Company products. "Suicide front axle" is a term that has been used for it. The configuration consists of a one-piece axle (solid front axle), to the ends of which the steerable front wheels are mounted. The axle receives its vertical and transverse support from a transverse leaf spring (leaf springs were often used for support in more than one direction), and its longitudinal support from fore-aft links sometimes called "radius rods" which are attached (via pivots) to the ends of the axle at their forward end and to the sides of the chassis (again via pivots) at their aft end. The ends of the transverse leaf spring can either tie to the top of the rods, or to the top of the solid axle. The transverse leaf spring is attached at its center to the center of the chassis's front cross member. 1919 Ford Model T Advantages and disadvantages In addition to simplicity lightness and compact shape, at least in some directions, since only the small end of the spring was attached to the wheel, it gave low unsprung weight. In addition to its contribution to ride and handling, this reduced wheel bearing loads and therefore allowed smaller cheaper bearings. Apparently the control of wheel motion was inferior to that of other suspension designs, even those of the first half of the 20th century. The modern Corvette leaf spring design does not use the spring for location.

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Leaf spring

A leaf spring is a simple form of spring commonly used for the suspension in wheeled vehicles. Originally called a laminated or carriage spring, and sometimes referred to as a semi-elliptical spring or cart spring, it is one of the oldest forms of springing, appearing on carriages in England after 1750 and from there migrating to France and Germany.   A traditional semi-elliptical Hotchkiss leaf spring arrangement. On the left, the spring is connected to the frame through a shackle. Leaf springs front independent suspension, front-wheel-drive Alvis1928 Independent front suspension by transverse leaf spring Humber 1935 Independent front suspension by semi-elliptical springs Mercedes Benz 230 W153 1938 Leaf spring on a German locomotive built by Orenstein-Koppel and Lübecker Maschinenbau A leaf spring takes the form of a slender arc-shaped length of spring steel of rectangular cross-section. In the most common configuration, the center of the arc provides location for the axle, while loops formed at either end provide for attaching to the vehicle chassis. For very heavy vehicles, a leaf spring can be made from several leaves stacked on top of each other in several layers, often with progressively shorter leaves. Leaf springs can serve locating and to some extent damping as well as springing functions. While the interleaf friction provides a damping action, it is not well controlled and results in stiction in the motion of the suspension. For this reason, some manufacturers have used mono-leaf springs. A leaf spring can either be attached directly to the frame at both ends or attached directly at one end, usually the front, with the other end attached through a shackle, a short swinging arm. The shackle takes up the tendency of the leaf spring to elongate when compressed and thus makes for softer springiness. Some springs terminated in a concave end, called a spoon end (seldom used now), to carry a swiveling member. The leaf spring has seen a modern development in cars. The new Volvo XC90 (from 2016 year model and forward) has a transverse leaf spring in high tech composite materials, a solution that is similar to the latest Chevrolet Corvette. This means a straight leaf spring, that is tightly secured to the chassis, and the ends of the spring bolted to the wheel suspension, to allow the spring to work independently on each wheel. This means the suspension is smaller, flatter and lighter than a traditional setup. History There were a variety of leaf springs, usually employing the word "elliptical". "Elliptical" or "full elliptical" leaf springs referred to two circular arcs linked at their tips. This was joined to the frame at the top center of the upper arc,...

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Corvette leaf spring

Corvette leaf spring commonly refers to a type of independent suspension that utilizes a fiber-reinforced plastic (FRP) mono-leaf spring instead of more conventional coil springs. It is named after the Chevrolet Corvette, the American sports car for which it was originally developed and first utilized. A notable characteristic of this suspension configuration is the mounting of the mono-leaf spring such that it can serve as both ride spring and anti-roll spring. In contrast to many applications of leaf springs in automotive suspension designs, this type does not use the spring as a locating link. While this suspension type is most notably associated with several generations of the Chevrolet Corvette the design has been used in other production General Motors cars, as well as vehicles from Volvo Cars and Mercedes-Benz. Fiat produced cars with a similar configuration, using a multi-leaf steel spring in place of the FRP mono-leaf spring. Design The C5 Corvette's rear suspension The leaf-spring suspension configuration is independent, because the movement of one wheel is not determined by the position of the other. Control arms are utilized to define the motion of the wheel as the suspension is compressed. The usual coil springs are replaced with a single FRP spring, which spans the width of the car. As in independent suspension systems using coil springs, and unlike the common leaf-spring supported Hotchkiss rear axle, the suspension kinematics are defined only by the control arms. As in a coil-spring suspension design, the FRP mono-leaf spring supports the weight of the vehicle. However, the FRP leaf springs differ from steel coils and traditional steel multi-leaf springs in a number of significant ways. The FRP plastic springs have 4.3–5.5 times the strain energy storage per weight, compared to steel. This results in a lighter spring for a given application. The single FRP mono-leaf front spring used on the fourth-generation Corvette is 33 percent of the weight of an equivalent set of coil springs. Comparing FRP to conventional steel leaf springs in similar applications, the weight saved is even greater. The third-generation Corvette offered an optional FRP mono-leaf spring as an alternative to the standard multi-leaf steel spring, the 22-kilogram (48 lb) steel spring being replaced by a 3-kilogram (7 lb) FRP spring. Volvo claims a weight savings of 5 kilograms (10 lb) by using a FRP spring in the rear suspension of its second-generation XC90, compared to designs using coil springs.In addition to the reduction in vehicle weight, the weight of the spring is partly unsprung mass. The relative sliding movement of the leaves of a multi-leaf steel spring results in stiction-based hysteresis with respect to spring compression. This...

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