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Introduction
This article will take an in-depth look at compression
springs.
The article will look at topics such as:
Principle of Compression Springs
Manufacturing Processes and Materials Used to Make
Compression Springs
Types of Compression Springs
Applications and Advantages of Compression Springs
Common Problems in Compression Springs
And much more…
Chapter 1: Principle of Compression Springs
This chapter will discuss what compression springs are and the
considerations when choosing compression springs.
What are Compression Springs?
Coil springs called compression springs can store mechanical
energy when they are compressed. These open-coiled, helical
springs provide resistance to compressive loading. When these
springs are subjected to a compression load, they compress, grow
shorter, and absorb a large amount of potential force.
The springs are forced back to their original lengths and forms
after the load is reduced or eliminated by the stored energy.
When weighted, compression springs become more compact. In
contrast to extension springs, compression springs' spiral wires
do not contact when they are relaxed; instead, when stressed,
they are tightly compressed.
How Compression Springs are Designed
All springs store and release energy, which requires engineers and designers to have intimate knowledge of the physics of springs. One of the basic principles of springs is that they are simple mechanisms that behave in a very predictable fashion. An important aspect of the design of springs is Hooke’s Law, which states that the more a spring is deformed, the more force is necessary to deform it. As a compression spring is compressed, more force is required to compress it.
The spring constant determines the amount of force necessary to deform a spring, which is measured in standard international (SI) units, Newtons per meter, or in pounds per inch. A higher spring constant means that a spring is stiffer. The wire diameter, coil diameter, free length, and number of active coils are the determining factors for the spring constant.
Since different springs have a different spring constant, it is essential that manufacturers know what the spring constant is to ensure the spring performs properly. If the spring constant is too high, or the wire is too thin, a spring could fail. Large scale springs have to be precision manufactured to guarantee they will not destabilize and cause damage. Spring coiling machines are carefully calibrated using the most precise and accurate calculations such that the produced spring is the right one for the job.
Considerations When Choosing Compression Springs
The are various considerations when choosing compression springs
which include:
Compression Spring End Types
Compression spring end types might be normal or customized.
Standard ends can be open or closed, or they can be ground or
not. Given the same number of coils, wire size, and outside
diameter (OD), open or closed ends will alter the spring rate.
Closed Ends
Closed ends stand vertically when placed on a flat surface since the last coil is closed. They are the most popular and economical ends since they do not require any form of extra processing. With applications that have a slenderness ratio, closed end compression springs will require a shaft or rod for extra support.
Ground Ends
Ground end compression springs are closed end compression springs that have their ends ground to the size of the spring. The grinding process increases manufacturing time and the cost of each spring. Grinding of ground end compression springs gives them a slenderness ratio to be able to function without the need of a rod or shaft.
Double Closed Ends
Double closed ends are similar to closed and squared ends. Instead of having one closed end, double closed end compression springs have two.. They are manufactured like extension and torsion springs with all coils touching. Double closed end compression springs have extra stability with a high slenderness ratio that requires a reinforced end in order to prevent buckling. They can be more economical than closed or ground end compression springs.
Open End
Open end compression springs are the least common type of compression springs because the open end does not allow the spring to stand or be stable without the assistance of a rod or shaft to keep the spring in place. AIl the coils are open and have pitch between them. Open end compression springs are used in applications where it is necessary to avoid increasing the solid height of the spring.
However, when combined with closed ends, this characteristic
will enhance the squareness of the loading force and lessen
spring buckling tendencies. Ground ends demand additional
manufacturing work.
Certain manufacturers, while not all, offer closed and ground
ends in their regular catalog stock designs; this is an
important distinction to understand. Examples of special ends
include expanded coils to snap into ring grooves, offset legs to
serve as alignment pins, and decreased coils for screw
attachment.
Compression Spring Material Considerations
Carbon steel and exotic alloys are only a few possible spring
materials. The most popular material is music wire, a high
carbon spring steel. Stainless steel 302 improves overall
corrosion resistance but is less strong than music wire.
Nickel alloys are chosen for their extreme high or low operating
temperatures, specialized corrosive conditions, and non-magnetic
properties. They are labeled under a variety of trademarks. In
addition, copper alloys with superior electrical conductivity
and corrosion resistance include phosphor bronze and beryllium
copper.
Compression Spring Physical Considerations
Outer Diameter (OD): If the compression spring is going into a hole, its outside diameter should be considered. In any case, if any internal components of the device will surround the spring, those must also be measured. A spring's outer diameter (OD) will enlarge when it is compressed, which is also important to consider if the spring will be used in a tube or a bore. Outer Diameter is measured from the outside of the coil on one side to the outside coil on the opposite side.
The outside diameter of springs is also subject to manufacturing
limitations, which can increase the assembly's needed envelope
size. Most spring manufacturers will specify a work-in-hole
diameter for a spring based on projected OD expansion and
manufacturing tolerance. Use this information to more
effectively express the product needs when obtaining custom-made
springs or to easily choose from stock spring catalogs.
Inner Diameter (ID): If the compression spring passes over a shaft or mandrel, the spring's inner diameter needs to be considered. To prevent friction, there must be a ten-thousandth of an inch between the shaft and the spring. Inner Diameter is calculated by subtracting two wire diameters from the outer diameter.
Free Length:
To ensure that the compression spring is in a preloaded state and stays in position, it is advised that its free length be a little bit longer than the available space. Free Length is the length of a compression spring before it is compressed, loaded or experiences any force. It is the length of the spring from end to end or tip to tip.
Solid Height: The wire diameter and the total number of
coils impact the solid height of the spring. Make sure the
loaded height is not shorter or taller than the solid height.
The setting in which the spring will be used includes the
temperature and additional components such as moisture. The more
expensive the spring’s material, the higher the temperature a
spring can withstand, but this will increase its cost.
Spring Pitch: Spring pitch is the distance between adjacent coils from the center of one wire to the center of another wire. The simplest method for measuring pitch is to measure the gap between the coils and add the thickness of a wire.
Active Coils: With compression springs, active coils are the coils that have pitch that deflect when the load is placed on the spring.
Total Coils: Total coils of a compression spring are all of the coils including the closed coils without pitch.
The use of compression springs requires an understanding of the number of total and active coils. Ones with closed and square ends or ground ends have one closed coil at each end, which are inactive. With open end compression springs, all of the coils in the spring are active and carry the load.
Compression Spring Load Considerations
The compression spring's loading or travel needs to be
considered as well. The relationship between the force needed to
compress a spring by a unit of length—typically pounds per inch
(lbs/in)—is known as the spring rate or spring constant. The
product designer can therefore determine projected spring travel
with a particular load. The spring is put under increasing
strain as it is driven further. The substance of the wire may
eventually give way under stress, leading to a phenomenon known
as spring set. The spring won't re-expand to its initial
unloaded length once it has been set. Nevertheless, depending on
the assembly, this spring may be useful.
Compression Spring Wire Diameters
The selection of the wire diameter for a compression spring, as well as the material, is a critical part of the design process. The wire has to meet the load and travel requirements and the environmental conditions. The Rockwell hardness scale indicates how hard the material is and how flexible or brittle the wire may be. Certain wire diameters are measured using a Rockwell tester indentation hardness process where a load is applied to the wire, and the depth of its penetration is recorded.
Types of Compression Spring Wire
High Carbon Spring Wire - High carbon spring wire includes music wire and hard drawn wire, which are made from different percentages of carbon and manganese. Depending on the carbon content, they have a Rockwell hardness of C31 or C60 with a working temperature of 250°F (121°C).
Alloy Steel Wire - Alloy steel wire is made of carbon, chromium, and silicon with a Rockwell hardness of C48 to C55 and a working temperature of 475°F (246°C).
Stainless Steel Wire - The grades of stainless steel used to produce compression wire are Series 302, 304, 316, A313, and 17-7 PH. Most stainless steel is made of chromium and nickel with series 316 having molybdenum as an extra ingredient. Stainless steel wire has a Rockwell hardness of C35 up to C57 with working temperatures that vary between 550°F (288°C) and 650°F (343°C).
Non-Ferrous Alloy Wire - Non-ferrous alloy wire includes phosphor bronze and beryllium copper. Their Rockwell hardness varies between C35 up to C104 with working temperatures between 200º F (93.8°C) and 400°F(204°C).
Compression Spring Wire Diameters
Music Wire and Stainless Steel Wire Diameters
Chrome Silicone Wire Diameters
English Units
Metric Units
English Units
Metric Units
0.008 in
0.203 mm
0.08 in
2.032 mm
0.009 in
0.229 mm
0.091 in
2.311 mm
0.010 in
0.254 mm
0.098 in
2.489 mm
0.011 in
0.279 mm
0.105 in
2.667 mm
0.012 in
0.305 mm
0.118 in
2.997 mm
0.013 in
0.330 mm
0.125 in
3.175 mm
0.014 in
0.356 mm
0.135 in
3.429 mm
0.015 in
0.381 mm
0.148 in
3.759 mm
0.016 in
0.406 mm
Up To
0.017 in
0.432 mm
0.162 in
4.115 mm
0.018 in
0.457 mm
0.172 in
4.369 mm
0.019 in
0.483 mm
0.187 in
4.750 mm
0.02 in
0.508 mm
0.312 in
7.925 mm
0.021 in
0.533 mm
0.343 in
8.712 mm
Up To
0.375 in
9.525 mm
0.362 in
9.195 mm
0.394 in
10.008 mm
0.375 in
9.525 mm
0.406 in
10.312 mm
0.394 in
10.008 mm
0.437 in
11.100 mm
0.437 in
11.100 mm
0.453 in
11.506 mm
0.453 in
11.506 mm
0.468 in
11.887 mm
0.468 in
11.887 mm
0.5 in
12.700 mm
0.5 in
12.700 mm
0.532 in
13.513 mm
0.562 in
14.275 mm
0.562 in
14.275 mm
0.625 in
15.875 mm
0.625 in
15.875 mm
Chapter 2: Manufacturing Processes and Materials Used to Make
Compression Springs
This chapter will discuss the manufacturing processes used in
making compression springs and the materials used.
Compression Springs Manufacturing Processes
The manufacturing processes used in making compression springs
include:
Coiling
Coiling first feeds the wire through a process of straightening.
The coiler will generate better parts if the wire is straighter
when it enters the coiler. During this step, CNC machinery with
preprogrammed settings modifies the arms and arbores to produce
the spring, adjusting factors including the spring's free
length, pitch, and coils. A high-speed camera records images as
the machines create the spring, allowing us to measure each
component and make adjustments as necessary to keep it within
tolerance. The product then moves on to the process of
alleviating stress after the machine cuts the spring from its
wire.
Stress Relieving
The substance of the wire is stressed during the coiling
process, which makes it brittle. We fix this by heating the
spring in an oven, which causes the coil to solidify in its new
shape and generate metallic links. For a predetermined period,
the oven maintains the temperature of the coil of wire at the
proper level before slowly allowing the coil to cool.
Finishing
Depending on its intended application, the wire is treated to a
number of finishing operations once it has gone through the
stress-relieving process. Completing a spring converts it from
its initial form into a specific tool that will enhance its
potential applications. The following are a few of the
procedures involved in spring finishing:
Grinding: Designers must grind the spring's ends flat,
enabling them to adhere to other surfaces more readily.
Strength peening: Strength peening prevents metal fatigue and
fractures in steel despite heavy use and frequent flexing.
Setting: Designers thoroughly compress the spring so that all
of its coils touch in order to establish its intended length
and pitch permanently.
Coating: Designers can coat the spring with non-corrosive
paint, submerge it in liquid rubber, or plate it with another
metal, such as zinc or chromium, to avoid corrosion.
Packaging: Designers develop specialized spring packagings,
such as bulk packaging in boxes or plastic bags.
Materials Used to Make Compression Springs
Steel materials that can be used to make compression springs
include stainless steel, hard-drawn steel, steel music wire, and
spring steel. Compression springs with wider wire diameters may
sustain more forceful use than springs with smaller wire
diameters. In general, the larger the wire, the stronger the
spring. Decreases in the coil diameter of the spring can also
increase its strength.
Due to its resistance to corrosion even when frequently exposed
to moisture and chemicals, stainless steel is a strong choice
for these applications. Steel is resilient and sturdy; it can
endure continuous use without breaking.
In addition to spring steel, other types of steel and even
plastic can be used to make springs. However, incorrectly
matching a spring with its application can result in early
failure, which can cause damage to nearby items and, in certain
situations, injury to humans.
It is crucial to choose the right material for spring
composition. Choosing a spring properly will maximize its
efficacy and lifespan. For spring materials, steel alloys are
typically employed. Low carbon, high carbon, stainless steel,
chrome silicon, and chrome vanadium alloys are common alloys.
Some metals, such as titanium, phosphor bronze, and beryllium
copper alloy, are employed occasionally as springs. Ceramic
materials are used for coiled springs used in high-temperature
environments.
Due to its high carbon steel composition, music wire can be
utilized for high-intensity applications, including gym
equipment, lawn and garden tools, and home improvement items.
Strings made of music wire have elasticity moduli of 30,000 psi
and minimum tensile strengths of 230-399 psi.
The springs typically found in commercial products like pens,
office supplies, toys, and other indoor-use items are made of
hard-drawn wire, a medium carbon steel. These springs can be
specifically adapted to various applications because of their
wide range of hardness, with Rockwell hardnesses ranging from
C31 to C52.
Characteristics of Compression Spring Material
Cold-drawn, hard-drawn wire is the least expensive spring
steel, typically employed for static loads and low stresses.
The material is not suited for temperatures below zero or more
than 2192 °F (1200 °C).
Cold-drawn, quenched, tempered, and all-purpose spring steel
is known as oil-tempered wire. However, it is not appropriate
for unexpected loads, exhaustion, or temperatures below zero
or above 3272 °F (1800 °C). Alloy steels are useful when we
opt for severely stressed circumstances.
Chrome Vanadium: is an alloy spring steel that can withstand
high temperatures and stresses of up to 3992 °F (2200 °C). It
has strong fatigue resistance and long shock and impact load
endurance.
Chrome Silicon can be used to make springs under a lot of
stress. It provides outstanding performance for long life,
shock loading, and temperatures up to 4532 °F (2500 °C).
Music wire is most frequently employed in small springs. It
can endure repeated loading at high pressures and is the
toughest material with the highest tensile strength. It cannot
be utilized at temperatures below zero or above 2192 °F (1200
°C). Music wire is typically a popular choice for springs.
Widely utilized alloy spring materials include stainless
steel.
Brass and phosphor bronze springs both have good electrical
conductivity and corrosion resistance. They are utilized
frequently for contacts in electrical switches. Brass springs
can be used in extremely cold temperatures.
Leading Manufacturers and Suppliers
Chapter 3: Types of Compression Springs
Different types of compression springs include:
Convex Compression Springs
Convex springs, also known as barrel-shaped springs, feature
coils with larger diameters in the center and coils with smaller
diameters at either end. When the springs are squeezed, their
designs enable the coils to fit inside one another. A
compression spring with the top and bottom outer diameters
smaller than the center outer diameter is known as a convex
spring. Convex springs are used to generate linear force.
Barrel springs can be produced in a wide range of diameters,
allowing for an infinite number of designs. Because it may save
space, eliminate buckling, and come in various shapes to better
fit any designs, a barrel spring is preferred by end users over
a generic compression spring. Telescoping or non-telescoping
barrel springs are both possible. Manufacturers use convex
springs in applications where more stability and movement
resistance are needed when the springs deflate. They are mostly
used in the toy, furniture, and automobile industries.
Conical Compression Springs
Conical springs are cone-shaped tapering springs. One end of the
spring has a diameter greater than the other, and the coils all
around the spring give a progressive taper or form shift. Some
conical springs have diameter variations between coils that
allow each coil to fit the one before it. These springs tend to
increase stability while lowering the solid height. Some cone
springs have their diameters adjusted to the point where,
because of their tapered cone shape, they will exhibit a
telescope effect when compressed. This allows the user to fully
compress the spring, causing all of the coils to collapse inside
of one wire diameter, giving more travel or deflection. This is
the best option if the product's creator requires a greater
deflection or travel distance.
Conical springs are superior to standard compression springs in
terms of stability. Since the larger outer diameter of tapered
springs is typically on the bottom, they provide better
stability, are less likely to buckle, and do not lose their
balance when compressed.
Disc Springs or Belleville Springs
The following image depicts the coned disk that makes up a
Belleville spring. Julian Belleville created it and registered
its design in France in 1867. The image below depicts the
typical load-deflection characteristics of a Belleville spring.
There are many different load-deflection curves available due to
the difference in the (h/t) ratio. Plate clutches, brakes,
relief valves, and a wide range of fastened connections require
Belleville springs.
These are the benefits of Belleville springs:
It is easy to manufacture and has a straightforward
construction.
It is a small spring assembly.
It is particularly helpful when a very strong force is
required to deflect a small spring.
It is adaptable since it offers a wide range of spring
constants.
Any linear or non-linear load-deflection characteristic can be
provided by it.
Coned disks can be stacked in series, parallel, or
series-parallel configurations depending on their size and
thickness. Without altering the design, these combinations
offer a variety of spring constants.
Double deflection for the same force is achieved by
series-connecting two Belleville springs. On the other hand,
when two Belleville springs are connected in parallel, the
force for a given deflection is approximately doubled.
Concave Springs
Concave springs, also known as hourglass springs, have a coil
that is narrower in the center than it is at either end. The
springs' symmetrical shape contributes to keeping them centered
at a specific location. A concave spring saves space, eliminates
buckling, and benefits numerous specialized places with its
design distribution. The end coils of a concave spring are wider
than the center coils; therefore, the pressure is distributed
unevenly, improving stability. There are more alternatives
because there are numerous different configurations to select
from that may be included in any design.
Straight Coil Compression Springs
Straight coil compression springs have the same OD and ID throughout the length of the spring.
Each coil of a straight spring has the same diameter. The ends of a straight coil compression spring can be ground or closed and have a bearing surface of 270o. The cylindrical shape of straight coil compression springs differentiates them from the cone shape of tapered compression springs.
Volute Springs
A volute spring has cone-shaped coils rather than wire with a
round, oval, or square cross-section. Similar to a conical
compression spring, they operate similarly. The cone shapes
slide over one another rather than being forced together by
compressive force. Compared to a non-conical compression spring
of the same length, a volute spring will compress down to a
lower solid height.
Variable Pitch Spring
The coils in variable pitch springs are spaced more widely in
some places and closer together in others. Pitch is the term for
the distance between adjacent coils of wire. Variable pitch
springs have different intervals between each coil along the
length of the spring.
Magazine Springs
To drive cartridges or bullets into the chamber of a handgun,
magazines use compression springs with oval or rectangular
coils. These springs need to be manufactured with extreme
accuracy and strict quality control. There are many different
spring design options available, with variations in length, coil
count, and required force. Since most magazine springs operate
close to their solid height, rate becomes a crucial design
consideration.
Torsional Springs
A torsion spring is a mechanical tool that stores and releases
rotational energy. The torsion spring is attached to a
mechanical part at each end. The winding of the spring is
tightened and stores potential energy when it is turned around
its axis at one end. As the other end is kept fixed, it is
deflected about the body's centerline axis. The spring stores
more potential energy as the winding becomes tighter and resists
more rotating force. The spring will unwind as it performs an
elastic rebound after being released, releasing the tensioned
energy.
The opposing end of the spring experiences an equal rotating
force, which might impart torque on the attached mechanical
component. Mechanical parts can be statically held in place by
torsion springs. As the spring is twisted to create a tighter
winding, it is more susceptible to bending stress than
rotational stress.
Unlike compression and tension springs, which are affected by
linear and rotational forces, these springs are different
because only rotating force is involved. To return to their
original winding after being twisted, they also rely on the
material's elasticity.
Depending on the direction of rotation, tension springs can
exert force either clockwise or counterclockwise. To provide the
most force, a torsion spring must be turned in the direction of
the winding.
There are several uses for torsion springs in practically every
industry and numerous variations of these springs.
Tapered Compression Springs
Tapered compression springs are cone shaped with a tapered body that has a larger outside diameter at the base and smaller outside diameter at the top. They offer stability in conditions where ordinary compression springs will buckle. Tapered compression springs have a solid low height for greater stability and resistance to surging. The solid height of tapered compression springs can be as low as the diameter of one wire. Tapered compression springs resist compression forces or store energy in the push mode.
Chapter 4: Applications and Advantages of Compression Springs
This chapter will discuss the applications and benefits of
compression springs.
Applications of Compression Springs
The applications of compression springs include:
Automobiles: Without at least some compression springs,
it would be very difficult to manufacture most cars.
Compression springs are used in automobiles in various places,
such as the seats, the hoses, and even the suspension. The
seats employ compression springs to conform to the body and
provide more comfort. To satisfy the wide variety of vehicle
compression spring uses, a variety of sizes and shapes are
naturally available.
Door locks:Traditionally, springs have been essential
to the proper function of door locks. Most metal locks contain
some steel spring due to the mechanism of a lock and key
system, which relies on the key to release the pressure
holding the bolt in place and maintaining the door's lock. A
spring generates that tension. Since the 1700s, compression
locks have been used for this purpose by locksmiths.
Pens: A compression spring can be observed by examining
a ballpoint pen. This spring enables the pen to write while
exposing the tip and then shields the tip inside the housing
to prevent the ink from drying out. This makes it possible to
use pens without cumbersome and easily lost caps.
Aeronautics: The majority of air travel would be
impossible without numerous types of springs. The springs on a
plane may not be visible, but air turbines, guidance systems,
engine controls, wheels, brakes, meters, fuel cells, and
diesel engines are just a few of the components in an airplane
that require springs.
Firearms: Whenever considering tension, consider
compression springs. Take into account the strain needed to
fire a bow and arrow. The crossbow is a much simpler weapon if
the human component is replaced with a compression spring.
Technological advancements continue with the modern
semi-automatic handgun, which uses a compression spring to
absorb the energy produced by recoil and then redirect it to
advance the slide or bolt and reload the weapon for the
subsequent shot.
Medical devices: Mechanical compression springs are
used in many medical device applications, from tiny springs
found in inhalers, pill dispensers, and syringes to many
diagnostic tools. Additionally, there are springs for various
medical devices, including catheters, valves, peristaltic
pumps, wheelchairs, endoscopic devices, staplers, and
surgical, orthopedic, and other tools.
Advantages of Compression Springs
The advantages of compression springs include:
Preventing another component's movement: The capacity
to stop another component from moving is one of compression
springs' greatest advantages. Thanks to this feature, a
minuscule compression spring is now an essential component of
the gauge's internal design and operation. The gauge's media
are pumped under pressure into a hollow tube, which seeks to
straighten up as it fills. This pressure causes the tube to
move, pushing a link and gear connected to the tiny
compression spring. The pressure indicator needle's location
is affected by the spring's resistance, pushing back, and
resistance.
Putting a component back in the right position: Door
latches on both automobiles and building doors are an
additional advantage that demonstrates how frequently utilized
and essential compression springs are. Imagine raising a
handle to open a door to get the greatest understanding of how
a spring operates. The lock mechanism's compression spring
would restore it to the locked position if the motion was used
without pulling the door open. The spring can be compressed by
tugging or turning the device; if it retains its position, the
spring will stay compressed; otherwise, it will latch once
more.
Applying continuous pressure: One of the most
significant and amazing advantages of compression springs is
in battery-operated products. Compression springs' continuous
pressure completes the secure electronic contact needed for
circuits inside all kinds of battery-operated gadgets. Think
of the separate battery slots in a child's toy or flashlight.
The small compression spring in each battery slot needs to be
gently squeezed to accommodate the battery. In addition to
holding the battery in place, the stored energy produced by
this compression also establishes the conductive connection
necessary for the device to draw power from the battery. Users
might not be surprised by some of these advantages; in fact,
users could be interested in compression springs because of
one of them. Compression springs are undoubtedly the greatest
option for applications of all sizes, across all industries,
and millions of different uses because they provide a special
mix of advantages.
Lightweight: Compression springs are remarkably
lightweight, considering the amount of force they can produce.
The spring is stronger thanks to the coiled steel than the
metal would be if it kept its original straight shape. Heating
and cooling also strengthen the metal, allowing for the use of
less material to support heavier weights.
Affordable: Most compression springs are composed of
steel and other affordable metals. These metals are readily
available worldwide and are inexpensive. Compression springs
are among the most cost-effective options for any usage since
they contain minimal metal.
Maintenance-free: A compression spring requires no
maintenance. The spring does not require lubrication,
cleaning, special coatings, or other maintenance to function.
The only issue with springs is that they could occasionally
break. However, replacing a broken compression spring is a
simple process.
Disadvantages of Compression Springs
The disadvantages of compression springs include:
Costly conical springs
Gets weaker if compressed over an extended period
Loses both stability and shape over time
Buckles when the axial load increases
Challenging to fix when broken
Chapter 5: Common Problems in Compression Springs
Common problems associated with compression springs include:
Surging in Springs
When one end of a helical spring is resting on a rigid support
and the other end is suddenly loaded, the coils will not deflect
uniformly because it takes time for the tension to propagate
along the spring wire. The spring's end coils in touch with the
applied load first absorb all of the deflection before
transferring a significant portion of that deflection to the
adjacent coils. A compression wave travels through the coils to
the supported end before reflecting to the deflected end. This
phenomenon can also be seen in a closed water body when a
disturbance flows in one direction before returning to where it
first appeared. This compression wave moves endlessly down the
spring. Resonance will happen if the applied load is variable
and the space between load applications is the same as the time
needed for the wave to move from one end to the other. The coils
experience extremely high strain and massive deflections as a
result. The spring could just barely fail in these
circumstances. This occurrence is called surge.
The following techniques can be used to stop the springtime
spring surge:
Equip the central coils with friction dampers to stop wave
propagation
Use springs of high natural frequency (the operating frequency
of the spring should be at least 15-20 times less than its
fundamental frequency)
Vary natural frequencies by using springs with coil pitches
towards the ends that differ from those in the middle.
Buckling in Springs
The spring behaves like a column and may fail by buckling at a
relatively modest load when the free length of the spring (LF)
is greater than four times the mean or pitch diameter (D),
according to experimental findings. The following relation can
be used to compute the critical axial load (Wcr) that results in
buckling.
Buckling can be avoided by:
Making the free length (LF) less than four times the coil
diameter (D)
Choosing a material with a higher degree of rigidity
Mounting the spring on a central rod or placing it in a tube
to prevent spring buckling
Minimizing clearance between the tube walls and the spring
while keeping it large enough to accommodate increase in
spring diameter during compression
Conclusion
Compression springs can store mechanical energy when they are
compressed. These open-coiled, helical springs provide
resistance to compressive loading. When these springs are
subjected to a compression load, they compress, grow shorter,
and absorb a large amount of potential force. The springs are
forced back to their original lengths and forms after the load
is reduced or eliminated by the stored energy.
Thus, the selection of compression springs has to be made in
consideration of the intended application, characteristics,
benefits, and disadvantages of compression springs.
Leading Manufacturers and Suppliers
Related Posts
Coil Springs
A coil spring is an elastic element made of metal or heavy
plastic in the form of curls or ringlets of round wire or cord
that is wrapped around a cylinder. The winding of a coil
spring can be loose or tight in a helical shape depending on
the application for which it is made...
Extension Springs
Extension springs are helical wound springs that are so
closely coiled together to create initial tension in the
coils. This initial tension creates resistance against the
force applied to its ends for extension. The initial tension
helps determine how closely and...
Metal Springs
Springs are a flexible machine element that store mechanical
energy when subjected to tensile, compressive, bending, or
torsional forces. When the spring is deflected, it stores
energy and at the same time exerts an opposing force...
Torsion Springs
A torsion spring is a mechanical device that stores and
releases rotational energy. Each end of the torsion spring is
connected to a mechanical component. As the spring is rotated
around its axis on one end, the winding of the spring is
tightened and stores potential energy...
Contract Manufacturing
Contract manufacturing is a business model in which a company
hires a contract manufacturer to produce its products or
components of its products. It is a strategic action widely
adopted by companies to save extensive resources and...
Wire Baskets
Wire baskets are made from a series of wires that are woven
together or welded to form a shape of a basket. They can also
be defined as containers that are made by use of an openwork
pattern of metal...
Wire Displays
Wire shaping is a complex method that encompasses a wide range
of dimensions, forms, and textures. The technique of creating
a usable product by wire bending and shaping is known as
custom wire forms...
Wire Forming
Wire forming is a method for applying force to change the
contour of wire by bending, swaging, piercing, chamfering,
shearing, or other techniques. The various techniques for wire
forming can produce any type of shape, form, or
configuration...
Wire Racks
A wire rack is a level wire form utilized to stock and exhibit
a number of products, usually retail. The bottom surface on
which such goods are stored is made of several latticed or
interlaced metal strands...