Types Of Mechanical Springs | Advantages and Applications Of Springs
DEFINITION FOR SPRING:
Springs are elastic bodies (generally metal) that can be twisted, pulled, or stretched by some force. They can return to their original shape when the force is released. In other words it is also termed as a resilient member.
spring is a resilient member capable of providing large elastic deformation. A spring is basically defined as an elastic body whose function is to distort when loaded and to recover its original shape when the load is removed. Mechanical springs are used in machines and other applications mainly
• to exert force,
• to provide flexibility
• to store or absorb energy.
In general, springs may be classified as either wire springs, flat springs, or special-shaped springs, and there are variations within these divisions. Wire springs include helical springs of round
or square wire that are cylindrical or conical in shape and are made to resist tensile, compressive, or torsional loads.
Main types Of Springs are:
Different types of springs and their purpose
Helical Spring –
Helical springs may subdivided into Compression(also called as Open Coil) and Tension springs (Also Called as Closed Coil Springs ) .
According to Cross section Helical Springs are Divided into another two types: Rectangular and Wire Springs
Special Purpose Springs
1) HELICAL TENSION SPRINGS:
• Figure shows a helical tension spring. It has some means of transferring the load from the support to the body by means of some arrangement.
• It stretches apart to create load.
• The gap between the successive coils is small.
• The wire is coiled in a sequence that the turn is at right angles to the axis of the spring.
• The spring is loaded along the axis.
• By applying load the spring elongates in action as it mainly depends upon the end hooks as shown in figure
1) Garage door assemblies
2) Vise-grip pilers
2) HELICAL COMPRESSION SPRINGS:
• The gap between the successive coils is larger.
• It is made of round wire and wrapped in cylindrical shape with a constant pitch between the coils.
• By applying the load the spring contracts in action.
• There are mainly four forms of compression springs as shown in figure..
1) Plain endThey are as follows:
2) Plain and ground end
3) Squared end
4) Squared and ground end
Among the four types, the plain end type is less expensive to manufacture. It tends to bow sideways when applying a compressive load.
1) Ball point pens
2) Pogo sticks
3) Valve assemblies in engines
3) TORSION SPRINGS:
• It is also a form of helical spring, but it rotates about an axis to create load.
• It releases the load in an arc around the axis as shown in figure
• Mainly used for torque transmission
• The ends of the spring are attached to other application objects, so that if the object rotates around the center of the spring, it tends to push the spring to retrieve its normal position.
• Mouse tracks
• Rocker switches
• Door hinges
• Automobile starters
4) SPIRAL SPRINGS:
• It is made of a band of steel wrapped around itself a number of times to create a geometric shape as shown in figure.
• Its inner end is attached to an arbor and outer end is attached to a retaining drum.
• It has a few rotations and also contains a thicker band of steel.
• It releases power when it unwinds.
• Alarm timepiece
• Automotive seat recliners
5. LEAF SPRING:
A Leaf spring is a simple form of spring commonly used in the suspension vehicles.
• Figure shows a leaf spring. Sometimes it is also called as a semi-elliptical spring, as it takes the form of a slender arc shaped length of spring steel of rectangular cross section.
• The center of the arc provides the location for the axle, while the tie holes are provided at either end for attaching to the vehicle body.
• Heavy vehicles, leaves are stacked one upon the other to ensure rigidity and strenth.
• It provides dampness and springing function.
• It can be attached directly to the frame at the both ends or attached directly to one end,usually at the front,with the other end attched through a shackle,a short swinging arm.
• The shackle takes up the tendency of the leaf spring to elongate when it gets compressed and by which the spring becomes softer.
Mainly in automobiles suspension systems.
• It can carry lateral loads.
• It provides braking torque.
• It takes driving torque and withstand the shocks provided by the vehicles.