For ten years, Lispring has been focusing on the R&D and production of wave springs and spiral retaining rings in the past, present and future, aiming to provide reliable and satisfactory products to global high-tech customers. We welcome your inquiries at any time.
I.Introduction
Although the spring industry is a small industry in the entire machinery manufacturing industry, its role cannot be underestimated. With the increasing degree of openness
With the continuous deepening of industrial automation, imported industrial equipment such as machinery manufacturing, automotive, petrochemical and power has been widely applied in China. Correspondingly, we have also learned about some new types of components with superior performance, and multi-layer wave springs are a relatively new type of elastic element.
A common single-layer wave spring is an elastic element with several peaks and valleys on a metal ring. A multi-layer wave spring appears to be composed of several common single-layer wave springs, but the difference is that it is not simply stacked, but is processed through a special continuous winding process.
II. Classification and working principle
Wave spring is usually divided into: a, single-layer wave spring,
Single-layer closed-type waveform spring in the shape of "O", single-layer open-type waveform spring in the shape of "C"; b. Multi-layer peak-to-peak (series) waveform spring; c. Multi-layer stacked peak type, also known as nested (parallel) type; Single-layer waveform spring: suitable for short displacement and medium-low elasticity working conditions, with good reliability and high working principle: waveform spring has the accuracy of dual working principles of cylindrical spring and disc spring. Multi-layer waveform spring peak-to-peak (series) type: the elasticity value is inversely proportional to the number of turns, which is mainly used in large displacement, medium-low elasticity requirements, and is a substitute for cylindrical spring. Nested (parallel) type: the force value of the spring is proportional to the number of turns, which can maintain all the precise characteristics of the waveform spring while generating huge elasticity. In many cases, the nested (parallel) waveform spring can be used instead of the disc spring.
The influence of material and temperature on fatigue failure is the same for the same material: materials with fine grain structure have higher yield strength and fatigue resilience than materials with coarse grain structure; surface strengthening treatment has much higher fatigue life than non-strengthening treatment; the smaller the surface roughness of the material, the lower the stress concentration, and the higher the fatigue strength; materials with metallurgical defects will also greatly reduce the fatigue life, resulting in early fatigue failure of the spring. The wave spring produced with ordinary spring steel has good elasticity, electrical conductivity, and wear resistance. Under normal temperature (temperature 200), the fatigue failure of the spring is within normal range. However, as the temperature increases, the elasticity of the spring will gradually decrease, and the failure phenomenon will significantly increase.
Stainless steel material processed wave spring has high fatigue life and good resistance to relaxation, while stainless steel also has high corrosion resistance, non-magnetic and other characteristics. Generally, stainless steel will fail when the temperature is higher than 400, but special stainless steel has high corrosion resistance, non-magnetic and other characteristics, and even when the working temperature reaches 650, it still has high resistance to relaxation and fatigue, making it an irreplaceable material in special working environments.
Fourth, prevention of fatigue failure of wave spring
The following are the load and stress calculation formulas for wave springs. We can use these formulas to design the stress of wave springs to be used in a low stress state, making fatigue failure of wave springs less likely.
(1) Calculation formula for single-layer wave spring: f=PKDm/Ebt3N4*ID/OD
S=3IIPDm/4bt2N2;
(2) The calculation formula for multi-layer series or peak-to-peak waveform springs: f=PKDm3Z/Ebt3N4*ID/OD;
S=3IIPDm/4bt2N2
(3) The multi-layered peak type, also known as the nested or parallel type waveform spring calculation formula; F=PKDm3/Ebt3N4Z*IDOD;
S=3IIPDm/4bt2N2Z;
Where: f=displacement; P=load; K=multi-turn coefficient; Dm=average diameter; Z=number of turns; E=elastic modulus; b=width of material;
t=thickness of material; N=wavenumber; ID=inner diameter; OD=outer diameter; S=bending stress; Through fatigue tests on wave springs, we have found that the fatigue life of wave springs is much greater than 500,000 times, normally exceeding 1 million times. The external diameter D=137mm, internal diameter d=125mm, thickness t=0.8mm, peak height H=6mm, and working displacement 3.5mm, the working force value F=1225N. This specification of wave spring has been used by a petrochemical enterprise for more than three years, and the life of the spring has reached 1.8 million times, and some even have a higher life.
Therefore, when designing a wave spring, we should choose a reasonable peak height and material thickness based on the load and displacement, effectively control the stress of the wave spring, and use adjustable wave numbers to more effectively control the fatigue failure of the wave spring.
