Contents
What causes the shaft of a DC motor to rotate?
The rotation of the DC motor is accomplished by the force which is developed on a current-carrying conductor in a magnetic field. The current-carrying conductor is connected to the shaft which is able to rotate relative to the stationary body of the DC motor.
How does load affect DC motor?
Load effect on a DC motor When the load increases, the current (Ia) increases. This current causes a higher voltage drop in the internal resistance of the motor (resistance of the excitation winding).
What makes a DC motor hard to turn?
One or more bearings could be damaged, for example. Sometimes a burned up motor can bind inside (windings scraping), especially if it is made to very tight tolerances. You might want to pull the brushes out and have a look at them. A motor without a gearbox should not show much resistance to turning.
Is it better to have speed control off the motor shaft?
Speed control off the motor shaft can be better for the life of the gearbox. It a encoder is placed on the output of the gearbox and if there is backlash in the gearbox the servoing done by the controller can cause the gear box to be exposed to more wear than otherwise would be the case.
How to achieve a constant speed on a motor?
To achieve a constant speed on your motor over varying loads you will need to build a closed loop control system. If you are into ready made subsystem components you could look at the Roboclaw motor speed control modules at the same ServoCity web site.
What is the synchronous speed of 4 pole induction motor?
The synchronous speed (zero torque)of 4 pole induction motor is 1500rpm @ 50Hz, or 1800rpm @ 60Hz. At full torque usually the speed is 1300rpm @ 50Hz, 1500@60Hz. Therefore you will need a reduction ratio of 1500/200 = 7.5 The gear reducer itself has a loss, then multiply calculted power with some margin.