Electromagnetic vibrating feeders use rubber springs and cylindrical coil springs to isolate vibration, and each has its own characteristics and application.
As shown in the figure, the vibration-insulating cylindrical compression coil spring has a simple structure, is easy to prepare, has a long service life, a small internal friction resistance, and good vibration isolation performance, and the stress and strain generally maintain a linear relationship within the elastic limit range. However, the lateral stability is poor, and the appropriate aspect ratio and support method should be adopted to withstand large compression, torsion and shear loads, and it is inconvenient to adjust the spring stiffness. Therefore, it is mainly used for large electromagnetic vibrating feeders.
A typical vibration isolation rubber spring has the following characteristics:
It is a molded part of various shapes, sizes and hardness, which can be manufactured by a mold and is easy to assemble. Different spring stiffness can be obtained by appropriately changing the relevant structural elements and combinations.
The same component is sufficient to withstand multi-directional loads, and the elastic mold is smaller, which is beneficial to improve the vibration isolation effect. Due to the large internal resistance, it can work reliably under near resonance without noise.
For a cylindrical rubber spring with a central long hole, its height should not be too large to avoid the phenomenon of sitting. In order to prolong the service life, it is required that the strain generated under a large load does not exceed the following values: when static, the compression is 15%, the shear is 20%; when it is dynamic, the compression is 5% and the shear is 8%.
Tests have shown that changing the amplitude, excitation frequency and temperature all affect the stiffness of the rubber spring. However, due to poor thermal conductivity and easy fatigue aging, it is mainly used for small and medium-sized electromagnetic vibrating feeders with light load.