7.1 INTRODUCTION TO SPRING DESIGN

Springs are among the most important and most often used mechanical components. Many mechanisms and assemblies would be virtually impossible to design and manufacture without the use of springs in one form or another. There are many different types of springs and spring materials. We will cover all the most important and common types and forms which are designed and manufactured today. See Fig. 7.1 for typical springs.

Figure 7.1: Samples of typical springs.

Spring types or forms are summarized as follows.

1. Compression springs, straight and conical

   1. Round wire

   2. Square wire

   3. Rectangular wire

2. Extension springs, straight

   1. Round wire

3. Torsion springs

   1. Round wire

   2. Square wire

4. Coil springs, spiral

5. Leaf springs

   1. Cantilever

   2. Both ends supported (beam)

6. Spring washers

   1. Curved

   2. Wave

7. Hair springs, very light load

8. Torsion bars

9. Belleville washers (disk springs)

Considerations Prior to the Spring Design Process. It is important when designing springs to adhere to proper procedures and design considerations. Some of the important design considerations in spring work are outlined here.

1. Selection of material for spring construction

   1. Space limitations: Do you have adequate space in the mechanism to use economical materials such as oil-tempered ASTM A229 spring wire? If your space is limited by design and you need maximum energy and mass, you should consider using materials such as music wire, ASTM A228 chrome vanadium or chrome silicon steel wire.

   2. Economy: Will economical materials such as ASTM A229 wire suffice for the intended application?

   3. Corrosion resistance: If the spring is...