Motor, as the core component of treadmill, why do I emphasize again and again: pay attention to motor when purchasing treadmill. So today, let’s talk about something professional. In the words of cross professionals, I will use a simple and clear introduction to explain how PMDC household treadmill works (I will express the meaning of PMDC right away). I think it’s important to grasp the basics so that you can understand why it’s important to choose the right home treadmill motor. The following points apply to most household treadmills and some commercial household treadmill motors. However, it is not suitable to use the most common AC motor in the newer commercial treadmill.
The rare earth permanent magnet direct current (PMDC) motor is made of fixed magnet and installed inside the casing. Across the middle of the motor is a shaft, which rotates the rolling bearing. The shaft connects the motor to the jogging of the household treadmill according to the driving pulley and belt. If you press and hold the start button on your home treadmill, it shows kinetic energy to rotate the jogging belt. Installed on the internal shaft of the motor is a transformer core (motor rotor), and there are several copper core wire rings around the transformer core, which are called winding resistance or electromagnetic coil. The amount of current depends on the copper winding resistance of the motor. The current comes from the motor control board, and the controller is connected with the motor according to two motor carbon brushes. The operation of the motor controller is to convert the AC working voltage of the wall power socket into the DC (direct current) working voltage required for the operation of the motor. When you connect the wall socket immediately, it won’t work easily! The motor control panel also allows you to change the motor speed according to the speed setting you choose on the home treadmill console and the amount of current entering the motor.
The figure shows a simplified layout of motor components. When the amount of current is based on the winding resistance inside the magnetic field, the electromagnetic coil will rotate, resulting in the rotation and fitness movement of the motor.
You can recall from your physics class the relationship between current, magnetism and fitness orientation, which can be described by Fleming’s right-hand rule. When you have never heard of it or don’t remember it, please don’t worry. The problem is very simple. The output power of the motor depends on the magnetic induction caused by the permanent magnet material and the current flowing through the copper winding resistance. In the motor, the driving force is called torque, which is very important, because you must ensure that you have sufficient torque so that the household treadmill can rotate stably if you stand on it. The torque of the motor is generally expressed by Thales or big horse force.
You can only increase the torque according to the electromagnetic field of the permanent magnet material or the amount of current flowing through the winding resistance. Combined with reality, you can’t improve the magnetic band of permanent magnet materials (they are permanent, you can’t change them!) Therefore, you can only increase the current according to the winding resistance to get a larger torque. The volume of the motor control board (MCB) that can be controlled by the specification of the copper core and the amount of current according to the current value of the copper core. When you try to rely on too much current, you can burn the copper windings, which will cause them to warm and melt, or you can load the MCB and make it ineffective.
Well, the operation process will never be seen again. In part 2, I will describe how the household treadmill motor burned down, which is very important.
After reading the above content, do you think you still can’t understand it? It doesn’t matter. What is the difference between HP and CHP motors? The more, the better? I have written an article before. You can read it in detail again!