Expert: Paul Soderman - 7/20/2008

Question
QUESTION: Sir, I am doing a project for which can you help me about how can I calculate and design a system for lifting the load of 5 to 7 kg using a smaller reciprocating IC engine about 5 to 10 cc capacity.

ANSWER: Aniket
Your first challenge is to decide how to transfer the power of the engine to a lifting system.  The usual way to do that is to incorporate a clutch and gear box with the engine and connect the drive shaft to a pulley system using a power take off belt.  If a clutch and gear box is more complicated than you want, you need power take off using, for example, a belt that connects to your drive shaft like a prony brake. A prony is one way of transferring power from one wheel to another using friction on a belt.  That is not very elegant, but it works.  Early mills used various mechanical devices to take power off a constantly turning water wheel for example.

Next you have to calculate the torque and power required to lift your load; this of course must match the capability of your engine.  Engine performance can be provided by the manufacturer.  If your load is connected to a simple pulley, the torque is the load time radius of the pulley.  Work is the load times height of lift.  And power is the rate of doing work.  These equations can easily be found online - google 'work, power'.

Beyond that I would need to know more about your system to give more definitive guidance.  Please contact me again if clarification is needed.
Paul

---------- FOLLOW-UP ----------

QUESTION: Sir, actualy my aim is to lift the load using the air pressure devloped by a fan driven by the IC engine and not by pulley system, and for that purpose I need to calculate the thrust that will generate enough power to lift this load of 5-6 kg.

ANSWER: Aniket
So you want to know what thrust it will take to lift a load of 5-6 kg.  Unless I misunderstand your question again, you will need a thrust equivalent to 5-6 kg or roughly 55 newtons.
Paul

---------- FOLLOW-UP ----------

QUESTION: Yes, so is it possible to achive this thrust by an IC engine of 5- 10 cc capacity reciprocating engine to a height of 8 - 10 inches, and if yes can you guide me how to get it.

Answer
How to get the engine... or how to get the height?  Aniket - your questions are so vague I don't really know what you are asking me.  Are you asking me about the fan, which is the key to your problem.  The fan will require a certain power input, but you have not said anything about the fan... what is it you need to know, and what are your requirements?
Paul