Compression spring application
The application range of compression springs is very wide, from automotive engines and large stamping machines to large electrical appliances and lawn mowers, as well as medical equipment, mobile phones, electronic products, and sensitive instrument devices. The most basic installation is anywhere a button is needed. Cone springs are commonly used in applications that require low solid height and increased wave resistance.
Design method of compression spring
All springs store and release energy, so engineers and designers must have a thorough understanding of spring physics. A spring is a simple mechanism whose behavior is predictable. A fundamental principle in spring design is Hooke's Law, which states that the force required to deform a spring is proportional to the amount of deformation. When the compression spring is compressed, the force required for the compression spring will increase.
The spring constant, measured in newtons per meter (SI unit) or pounds per inch, determines the force required for spring deformation. The larger the spring constant, the greater the spring stiffness. The factors that affect the spring constant include wire diameter, coil diameter, free length, and effective number of coils.The energy stored in a compressed spring depends on the material properties, wire diameter, and number of coils of the spring. The speed or stiffness of a spring depends on the wire diameter and number of coils. The velocity of a spring is the change in force per unit length, measured in pounds per inch or newtons per millimeter. The speed of the spring can be adjusted by changing the wire diameter or the number of coils.
Physical considerations for compression springs
Outer diameter (OD): When inserting a compression spring into a hole, its outer diameter must be considered. If the spring is to be surrounded by any internal components of the device, their dimensions should also be measured. The outer diameter (OD) of a spring will expand during compression, which is crucial if the spring is used in a tube or hole. OD is measured from the outer edge of one coil to the outer edge of the other coil.
The manufacturing process has limitations on the outer diameter of the spring, which may affect the required housing size for assembly. Spring manufacturers typically provide the working hole diameter based on the expected outer diameter expansion and manufacturing tolerances. This information is crucial for specifying your needs when ordering custom springs or selecting from inventory catalogs.
Inner diameter (ID): When installing a compression spring on a shaft or spindle, its inner diameter must be considered. To avoid friction, a small gap of at least one ten thousandth of an inch should be maintained between the shaft and the spring. The inner diameter is determined by subtracting twice the wire diameter from the outer diameter.
Compression spring inner diameter
Free length: To ensure that the compression spring maintains its preloaded state and position, it is recommended that the free length be slightly larger than the available space. Free length refers to the length of a compression spring when it is not compressed, loaded, or subjected to any force. It is measured from one end of the spring to the other or from the tip to the tip.
Compression spring free length and solid height
Physical height: The physical height of the spring is determined by the wire diameter and the total number of coils. Ensure that the load height of the spring does not exceed or fall below its physical height.
The working environment of a spring, including factors such as temperature and humidity, can affect its performance. Although more expensive materials can withstand higher temperatures, they also increase the overall cost of the spring.
Spring pitch: Spring pitch refers to the space between adjacent coils, measured from the center of one wire to the center of another wire. To determine the pitch, measure the gap between the coils and add the thickness of the wire.
Measure the pitch of the compression spring
Active coil: In a compression spring, an active coil refers to a coil that compresses and deflects when a load is applied to the spring. These coils are responsible for the movement and function of the spring.
Number of bus coils: The number of bus coils in a compression spring includes the effective coils and any closed coils without pitch, which do not participate in deflection.
When choosing a compression spring, it is important to understand the total number of coils and the effective number of coils. The closed end or ground end spring has non effective coils at the end, while all coils of the open end compression spring are effective and participate in carrying the load.
Understanding the spring constant is crucial for manufacturers to ensure appropriate spring performance. If the spring constant is too high or the spring wire is too thin, the spring may fail. Large springs must be precisely manufactured to avoid instability and potential damage. The spring winding machine is carefully calibrated through precise calculations to ensure that the produced springs meet the required specifications.
