# COMBINATIONS OF SPRINGS & SPRING MATERIALS

## COMBINATIONS OF SPRINGS- ANALYSIS OF MULTI-SPRING SYSTEMS

COMBINATIONS IN SPRINGS: In many practical applications, we use the springs in machine systems. Often observed that we use a System of Springs rather than using many springs individually in a mechanism. This technique practically has many advantages as well as efficient and smooth working.

This spring system usually known as the COMBINATIONS OF SPRINGS.

### TYPES OF SPRING COMBINATIONS:

There are two types of Spring Combinations:

1) SERIES COMBINATION

2) PARALLEL COMBINATION

### OBJECTIVES OF SPRING COMBINATIONS:

The objectives of Spring Combination(series and parallel) combination are :

1) Used to save the space in a mechanism.

2) Enables better rate of spring at a certain deflection

3) Provides a better way in order to do safe design.

### SPRING COMBINATIONS:

#### A) SERIES CONNECTION

Here, two springs with spring constants K1 & k2 connected in series with each other in order to from the combination.

For series connection;

1) The force acting on each spring is same and also equal to the External force.

2) Total deflection in the spring combination is equal to the sum of the deflections of individual springs.

Therfore, the final equation is shown above;

where k= Combined Stiffness of combination

#### B) PARALLEL CONNECTION

Here, two springs with spring constants K1 & k2 connected in parallel with each other in order to from the combination.

For parallel connection;

1) Total force acting on the spring combination is equal to the Sum of the forces acting on the individual springs.

2) The deflection of each spring is same and also equal to the Deflection of
the combination.

## SPRING MATERIALS:

### SELECTION OF SPRING MATERIAL:

The basic selection of a spring material for the spring wire depends upon the following factors:

1) Load acting on the spring

2) Range of stress through which the spring has to work

3) Limits on mass and volume of spring

4) Expected fatigue life

5) Environmental conditions on which it will work such as High temperature and corrosive atmosphere.

6) Level of deformation that came during spring making

### TYPES AND VARIETIES OF STEEL WIRE USED FOR SPRING DESIGN:

There are four basic varieties of Steel wire used for this purpose :

1) Patented and Cold-Drawn steel wires ( Usually Unalloyed)

2) Oil Hardened and Tempered spring steel wires and valve spring wires

3) Oil Hardened and Tempered steel wires (Usually Alloyed)

4) Stainless steel spring wires