Please help me in designing the bush for breake pedal. what are the parameters are required to design the bush. Any standard are available for calculating the strength, life, etc. before proceeding the design of bush. kindly help me.

 

Sounds kind of like a homework problem, and I hate to do peoples work for them, and their professors probably feel the same way.

It is often best to describe what work you have done yourself before asking any question. Are we to do all all of the problem including asking the important questions?

You should choose the bushing from a catalog. It would be cost inefficient to design something this easy to find as a stock part. You can probably let the dimensions of the bushing follow the design of the pedal and how much force you think the driver will apply. You have to select the material according to the environment of use. An open cab, or a motorcycle will be different from an close cab of a car, or a bulldozer. No reason you cannot use a composite or plastic bushing in some applications.

 

Agree with Michael you could use a Glycodur PTFE impregnated bush which can take massive loads for their size at low speeds

 

I agree with Michael!
However, about the required parameters, you need to define your application first:
- v = pin velocity (i mean the velocity of the part that rotates or slides in the bushing);
- F = forces applied on the bushing surfaces by the pin;
- P = load capacity of the bushing (P= F/A where A is the projection of the internal area of the bushing)

Once you have these factors you need to compare them with those provided by the Maker. You can easily find them in the catalogs.

Other important parameters are:
- static or dinamic load?
- dry friction or oil lubrication?
- presence of contaminants (chemical, dust particles, water, etc)
- housing and pin materials: this is extremely important for the heat exchange. Don't forget that one of the most important failure factors is the temperature!
- p*v product