If you are looking for more details, kindly visit HEGONG SPRING.
Belleville washerA Belleville washer, also known as a coned-disc spring,[1] conical spring washer,[2] disc spring, Belleville spring or cupped spring washer, is a conical shell which can be loaded along its axis either statically or dynamically. A Belleville washer is a type of spring shaped like a washer. It is the shape, a cone frustum, that gives the washer its characteristic spring.
The "Belleville" name comes from the inventor Julien Belleville who in Dunkerque, France, in patented a spring design which already contained the principle of the disc spring.[1][3] The real inventor of Belleville washers is unknown.
Through the years, many profiles for disc springs have been developed. Today the most used are the profiles with or without contact flats, while some other profiles, like disc springs with trapezoidal cross-section, have lost importance.
[
edit
]
Cross-sectional view of an M4 anti-tank mine (circa ) showing the steel Belleville spring in the fuze mechanism Cut-away view of an M14 antipersonnel landmine, showing the firing pin mounted in the centre of a plastic Belleville springIn the different fields, if they are used as springs or to apply a flexible pre-load to a bolted joint or bearing, Belleville washers can be used as a single spring or as a stack. In a spring-stack, disc springs can be stacked in the same or in an alternating orientation and of course it is possible to stack packets of multiple springs stacked in the same direction.
Disc springs have a number of advantageous properties compared to other types of springs:[4]
Thanks to these advantageous properties, Belleville washers are today used in a large number of fields, some examples are listed in the following.
In the arms industry, Belleville springs are used, for instance, in a number of landmines e.g. the American M19, M15, M14, M1 and the Swedish Tret-Mi.59. The target (a person or vehicle) exerts pressure on the Belleville spring, causing it to exceed a trigger threshold and flip the adjacent firing pin downwards into a stab detonator, firing both it and the surrounding booster charge and main explosive filling.
Belleville washers have been used as return springs in artillery pieces, one example being the French Canet range of marine/coastal cannon from the late s (75 mm, 120 mm, 152 mm).
Some makers of bolt action target rifles use Belleville washer stacks in the bolt instead of a more traditional spring to release the firing pin, as they reduce the time between trigger actuation and firing pin impact on the cartridge.[5]
Belleville washers, without serrations which can harm the clamping surface, have no significant locking capability in bolted applications.[6]
On aircraft (typically experimental aircraft) with wooden propellers, Belleville washers used on the mounting bolts can be useful as an indicator of swelling or shrinkage of the wood. By torquing their associated bolts to provide a specific gap between sets of washers placed with "high ends" facing each other, a change in relative moisture content in the propeller wood will result in a change of the gaps which is often great enough to be detected visually. As propeller balance depends on the weight of blades being equal, a radical difference in the washer gaps may indicate a difference in moisture content &#; and thus weight &#; in the adjacent blades.
In the aircraft and automotive industries (including Formula One cars[7][better source needed]) disc springs are used as vibration-damping elements because of their extremely detailed tuning ability. The Cirrus SR2x series of airplanes, uses a Belleville washer setup to damp out nose gear oscillations (or "shimmy").[8]
In the building industry, in Japan stacks of disc springs have been used under buildings as vibration dampers for earthquakes.[9]
Belleville washers are used in some high pressure air regulators, such as those found on paintball markers and air tanks.
[
edit
]
Belleville spring stack in series Belleville spring stack in parallelMultiple Belleville washers may be stacked to modify the spring constant (or spring rate) or the amount of deflection. Stacking in the same direction will add the spring constant in parallel, creating a stiffer joint (with the same deflection). Stacking in an alternating direction is the same as adding common springs in series, resulting in a lower spring constant and greater deflection. Mixing and matching directions allow a specific spring constant and deflection capacity to be designed.
Generally, if n disc springs are stacked in parallel (facing the same direction), standing the load, the deflection of the whole stack is equal to that of one disc spring divided by n, then, to obtain the same deflection of a single disc spring the load to apply has to be n times that of a single disc spring. On the other hand, if n washers are stacked in series (facing in alternating directions), standing the load, the deflection is equal to n times that of one washer while the load to apply at the whole stack to obtain the same deflection of one disc spring has to be that of a single disc spring divided by n.
[
edit
]
In a parallel stack, hysteresis (load losses) will occur due to friction between the springs. The hysteresis losses can be advantageous in some systems because of the added damping and dissipation of vibration energy. This loss due to friction can be calculated using hysteresis methods. Ideally, no more than 4 springs should be placed in parallel. If a greater load is required, then factor of safety must be increased in order to compensate for loss of load due to friction. Friction loss is not as much of an issue in series stacks.
In a series stack, the deflection is not exactly proportional to the number of springs. This is because of a bottoming out effect when the springs are compressed to flat as the contact surface area increases once the spring is deflected beyond 95%. This decreases the moment arm and the spring will offer a greater spring resistance. Hysteresis can be used to calculate predicted deflections in a series stack. The number of springs used in a series stack is not as much of an issue as in parallel stacks even if, generally, the stack height should not be greater than three times the outside diameter of the disc spring. If it is not possible to avoid a longer stack, then it should be divided into 2 or possibly 3 partial stacks with suitable washers. These washers should be guided as exactly as possible.
As previously said, Belleville washers are useful for adjustments because different thicknesses can be swapped in and out and they can be configured to achieve essentially infinite tunability of spring rate while only filling up a small part of the technician's tool box. They are ideal in situations where a heavy spring force is required with minimal free length and compression before reaching solid height. The downside, though, is weight, and they are severely travel limited compared to a conventional coil spring when free length is not an issue.
A wave washer also acts as a spring, but wave washers of comparable size do not produce as much force as Belleville washers, nor can they be stacked in series.
For disc springs with a thickness of more than 6.0 mm, DIN specifies small contact surfaces at points I and III (that is the point where the load is applied and the point where the load touches the ground) in addition to the rounded corners. These contact flats improve definition of the point of load application and, particularly for spring stacks, reduce friction at the guide rod. The result is a considerable reduction in the lever arm length and a corresponding increase in the spring load. This is in turn compensated for by a reduction in the spring thickness.
The reduced thickness is specified in accordance with the following conditions:[4]
As the overall height is not reduced, springs with reduced thickness inevitably have an increased flank angle and a greater cone height than springs of the same nominal dimension without reduced thickness.[4] Therefore, the characteristic curve is altered and becomes completely different.
[
edit
]
Parameterization of a Belleville disk springStarting from , when J. O. Almen and A.Làszlò published a simplified method of calculation,[10] always more accurate and complex methods appeared also in order to include in calculations disc springs with contact flats and reduced thickness. So, although today there are more accurate methods of calculation,[11] the most used are the simple and convenient formulas of DIN as, for standard dimensions, they produce values which correspond well to the measured results.
Considering a Belleville washer with outside diameter D e {\displaystyle {D_{e}}} , inside diameter D i {\displaystyle {D_{i}}} , height l {\displaystyle {l}} and thickness t {\displaystyle {t}} , where h 0 {\displaystyle {h_{0}}} is the free height, that is the difference between the height and the thickness, the following coefficients are obtained:
δ = D e D i {\displaystyle \delta ={\frac {D_{e}}{D_{i}}}}
C 1 = ( t &#; t ) 2 ( 1 4 &#; l t &#; t &#; t + 3 4 ) &#; ( 5 8 &#; l t &#; t &#; t + 3 8 ) {\displaystyle {C_{1}}={\frac {\left({\frac {t'}{t}}\right)^{2}}{\left({\frac {1}{4}}\cdot {\frac {l}{t}}-{\frac {t'}{t}}+{\frac {3}{4}}\right)\cdot {\left({\frac {5}{8}}\cdot {\frac {l}{t}}-{\frac {t'}{t}}+{\frac {3}{8}}\right)}}}}
C 2 = C 1 ( t &#; t ) 3 &#; [ 5 32 &#; ( l t &#; 1 ) 2 + 1 ] {\displaystyle {C_{2}}={\frac {C_{1}}{\left({\frac {t'}{t}}\right)^{3}}}\cdot \left[{\frac {5}{32}}\cdot \left({\frac {l}{t}}-1\right)^{2}+1\right]}
K 4 = &#; C 1 2 + ( C 1 2 ) 2 + C 2 {\displaystyle {K_{4}}={\sqrt {-{\frac {C_{1}}{2}}+{\sqrt {\left({\frac {C_{1}}{2}}\right)^{2}+C_{2}}}}}}
The equation to calculate the load to apply to a single disc spring in order to obtain a deflection s {\displaystyle {s}} is:[12]
F = 4 E 1 &#; μ 2 &#; t 4 K 1 &#; D e 2 &#; K 4 2 &#; s t &#; [ K 4 2 &#; ( h 0 t &#; s t ) &#; ( h 0 t &#; s 2 t ) + 1 ] {\displaystyle F={\frac {4E}{1-\mu ^{2}}}\cdot {\frac {t^{4}}{K_{1}-{D_{e}}^{2}}}\cdot {K_{4}}^{2}\cdot {\frac {s}{t}}\cdot \left[{K_{4}}^{2}\cdot \left({\frac {h_{0}}{t}}-{\frac {s}{t}}\right)\cdot \left({\frac {h_{0}}{t}}-{\frac {s}{2t}}\right)+1\right]}
Note that for disc springs with constant thickness, t &#; {\displaystyle {t'}} is equal to t {\displaystyle {t}} and consequently K 4 {\displaystyle {K_{4}}} is 1.
For what concerns disc springs with contact flats and reduced thickness it has to be said that a paper published in July , demonstrated that the K 4 {\displaystyle {K_{4}}} equation as defined inside the standard norms is not correct as it would result in every reduced thickness being considered right and this is, of course, impossible. As written in that paper K 4 {\displaystyle {K_{4}}} should be replaced with a new coefficient, R d {\displaystyle {R_{d}}} , which depends not only from the t &#; t {\displaystyle {\frac {t'}{t}}} ratio but also from the flank angles of the spring.[13]
The spring constant (or spring rate) is defined as:
k = d F d s {\displaystyle {k}={\frac {dF}{ds}}}
If friction and bottoming-out effects are ignored, the spring rate of a stack of identical Belleville washers can be quickly approximated. Counting from one end of the stack, group by the number of adjacent washers in parallel. For example, in the stack of washers to the right, the grouping is 2-3-1-2, because there is a group of 2 washers in parallel, then a group of 3, then a single washer, then another group of 2.
The total spring coefficient is:
K = k &#; i = 1 g 1 n i {\displaystyle K={\frac {k}{\sum _{i=1}^{g}{\frac {1}{n_{i}}}}}}
K = k 1 2 + 1 3 + 1 1 + 1 2 {\displaystyle K={\frac {k}{{\frac {1}{2}}+{\frac {1}{3}}+{\frac {1}{1}}+{\frac {1}{2}}}}}
K = 3 7 &#; k {\displaystyle K={\frac {3}{7}}\cdot {k}}
Where
n i {\displaystyle n_{i}}
g {\displaystyle {g}}
k {\displaystyle {k}}
So, a 2-3-1-2 stack (or, since addition is commutative, a 3-2-2-1 stack) gives a spring constant of 3/7 that of a single washer. These same 8 washers can be arranged in a 3-3-2 configuration ( K = 6 7 &#; k {\displaystyle K={\frac {6}{7}}\cdot k} ), a 4-4 configuration ( K = 2 &#; k {\displaystyle K=2\cdot k} ), a 2-2-2-2 configuration ( K = 1 2 &#; k {\displaystyle K={\frac {1}{2}}\cdot k} ), and various other configurations. The number of unique ways to stack n {\displaystyle {n}} washers is defined by the integer partition function p(n) and increases rapidly with large n {\displaystyle {n}} , allowing fine-tuning of the spring constant. However, each configuration will have a different length, requiring the use of shims in most cases.
[
edit
]
[
Want more information on belleville disc? Feel free to contact us.
14]
[
2]
[
edit
]
A coil spring may not work well in confined space that needs high load. What you should be using is a Belleville washer. Go through this Belleville washer review to learn more!
A Belleville washer is a type of compact, washer-shaped spring. Other terms for this item include "conical spring washer," "coned-disc spring," "cupped spring washer" and "Belleville spring." These washers are used for many applications and can be constructed out of various materials, including stainless steel. They are often used to add flexibility to bolted joints. Stacking one Belleville washer atop another in a certain orientation will influence deflection.
Belleville washers are used to solve many problems, such as thermal expansion, bolt creep and vibration-related problems. A Belleville washer is designed to generate a great amount of force in a short, compact spring design. When compressed, a coned-disc spring offers great force with minimal movement. A properly constructed Belleville washer will not relax by a significant amount even when it is under pressure for a period of time. They are designed to withstand years of regular compression without deforming.
Most Belleville washers are constructed out of grades of steel such as carbon steel and stainless steel. A type of steel called 18-8 stainless steel is one of the more popular types of stainless steel that manufacturers use to create Belleville washers. This non-magnetic type of steel contains 18 percent chromium and 8 percent nickel. Chromium and nickel add to the steel&#;s corrosion resistance.
Carbon steels contain more carbon than other grades of steel. They are easily stamped, forged, machined, cast and wrought into shape. Carbon increases a Bellville washer&#;s hardness and overall strength.
The average Belleville washer is engineered with an outer coating to increase the desirable properties of the washer&#;s base metal. Inorganic aluminum and zinc compound coatings contribute to increases in the washer's electrical conductivity and corrosion resistance. Most conical spring washers that are made out of carbon steel feature zinc phosphate coatings to increase corrosion resistance. Nickel plating leaves a Belleville washer with a smooth, even finish. Adding nickel plating to a washer increases the overall corrosion resistance of the spring.
Belleville washers are constructed to fit the sizes of most traditional screws. They have diameters from about 0.2-2.5 inches (4.75-63.5 mm). The diameter of the hole in the middle typically measures about 0.1-1.0 inches (2.54-25.4 mm).
Ever since I bought a race car, I spend most of my weekends on the field trying to win against my friends. I love the thrill of racing, and I don&#;t view my hobby as a dangerous one. I, however, got into an accident on the field since my brakes failed and my car was not moving at the expected speed. This was a wakeup call for me, and I had to make some major adjustments. A friend recommended installing a Belleville washer which has made a significant difference. It has not only increased the speed of my racecar but also enhanced my brake system.
In , Julien Belleville came up with a spring design which used the same principle as a disc spring. He named it Belleville washer or a cupped spring washer. Belleville washer is a conical shell that is used as a spring. It is a form of spring washer that is categorized under disc springs. In layman&#;s language, a disc spring refers to a circular element that deforms to a short height when you subject it to a load along its symmetrical axis.
Belleville washer comes in the form of a convex disc that is supported on its outer part. It uses an opposing force at the center part of the disc. This disc spring can generate high force in a short spring length without moving a lot during compression.
You can use the Belleville washer to apply pre-load to a bearing surface or bolted joints. It is possible to engineer this disc spring to deliver loading profiles that other elements such as coiled springs cannot. This disc spring can support a big load with minimum weight requirements and space.
You can use Belleville washer in bolted applications since it provides high tension. The disc spring is also suitable for dampening function due its shock absorbing capabilities. It exerts even pressure which remains constant making it suitable for situations wear tension losses due to wearing of parts or thermal contraction.
Configuring Belleville&#;washer in stacks or single spring allows it to support a large load. Stacking Belleville washers can help you produce a linear or regressive load-vs-deflection trend. The stack options include series stacks or parallel stacks. Parallel stacks are meant to raise the maximum load allowance as you add each Belleville washer. When using Belleville washer as a stack in parallel units, you should consider the amount of friction. Stacking creates sliding friction at the moving surfaces causing deflection.
Series stacks can raise the amount of travel. You can also combine both series and parallel stacks when you need a better performance. This combination can fine tune the spring characteristics to suit your application needs.
Pros
&#; It works better than a coil spring due to its high load capacity
&#; You can adjust the load characteristics by stacking
&#; It absorbs shock
Cons
&#; They are bulky
&#; Not ideal for light applications
This washer supports a high load due to its conical configuration with minimal deflections. They are designed to solve problems such as vibration as well as thermal expansion or contraction.
A coil spring contains a coiled metal which is loosely attached. It is ideal for light applications. Belleville washer is strong and meant for heavy duty use due to the use of a conical spring and a raised center.
Manufacturers use stainless steel to produce this disc springs. The material is corrosion resistant, and they include a coating that also extends the lifespan of the washer.
Yes. As long as the Belleville washer is still in good condition showing no signs of being damaged, you can reuse it. Make sure that its height is within tolerance before reusing it.
Will the dimensions of this washer change once it is compressed?
Yes, but the inner and outer changes in dimension do not affect the performance of the washer.
From my Belleville washer review, I discovered that this washer is different from others such as bespoke springs and coil springs. It is a conical spring that has a raised center forming the shape of a cone. Belleville washer can easily manage a heavy load and distribute its weight uniformly to offer great stability. It can remain stable under pressure without the risk of deforming. I like the fact that they are strong and can last longer than traditional springs.
For more information, please visit flange bolt washer.