Torque is one of the main characteristics of action of force. To define it, it is necessary to know force operating on a body, a point of its annex to a body and a point of rotation of a body. Torque can be measured, knowing the power which is developed by the engine.
It is required to you
- - ruler or roulette;
- - stop watch;
- - tachometer;
- - dynamometer;
- - ampermeter.
Instruction
1. Find a point of application of force and a point around which the body rotates. Measure distance between them. It will be force shoulder. Define the direction of action of force in a point of its application, by means of a dynamometer measure its value. Using a protractor or the angle meter, find an acute angle between a straight line on which the shoulder of force and force is located.
2. Find torque, having multiplied value of force on her shoulder and a sine of an acute angle between them (M=F • l· sin(α)). If moment of force is perpendicular to her shoulder that sin(α)=1 and under these conditions the maximum moment develops. At arrangement of force and a shoulder along one line, sin(α)=0, and moment of force is equal to zero too.
3. The engine performing work develops the torque which is the algebraic sum of many moments of forces operating on various details of the engine. Therefore the simplest option is to learn torque from technical documentation which is attached to the device.
4. If such information is not available, by means of the tachometer measure the frequency of turns of a shaft of the engine in revolutions per minute. Measure engine capacity or learn from documentation, having expressed it in kilowatts. Find value of torque, having increased engine capacity by 9550 and having divided into the frequency of rotation of a wave of M=P•9550/n.
5. To calculate frame torque with current in magnetic field which is a basis of any electric motor teslametry measure induction of magnetic field in which it is. Measure distance from a rotation axis to the vertical conductor of a frame – it will be a shoulder of the operating force. Measure length of vertical conductors.
6. Connect a frame to a current source, measure by the ampermeter current in it. Find the maximum torque for such frame, having increased number 2 (as vertical conductors two) by value of magnetic induction, current, length of the vertical conductor and a shoulder of force M=2·B·I· l·r. To find electric motor torque, increase this value by quantity of rounds of a winding.