Everyone, do you think about whether the energy in the operation of the electric motor eventually be

Let me talk about the energy transformation in this process:

The electric energy of the power supply is given to the motor, and the motor can work, in which the electric energy consumption of the motor is in two aspects: 1. Conversion into mechanical energy: used for work in other aspects (mechanical energy is converted into something else, there are not many examples of pure energy conversion, but the side is very common, like a chainsaw, there is not much energy conversion, except for useless irregular heat energy and some sound energy, but it destroys the internal molecular structure of the cut object to do work).

Or just stay in the mechanical energy (such as the fan, the fan rotation is not in vain, this is all energy) 2, due to the heating of the coil to produce internal energy, which is a very small part, can be regarded as loss. If you hold the motor that is running with an iron rod, then the electrical energy and internal energy can be converted "with high efficiency", and the motor will soon break.

Mechanical energy is the work done, for example, friction. Then in the end, it's heat.

Says who? Does mechanical energy not include kinetic energy potential energy?

For example, the fan turns.

It's a part of the energy that is consumed by friction.

But the fan itself also has kinetic energy.

And because of the friction with the air and the friction between the blades and the fan itself.

A lot of energy is expended on the blades.

The workmanship of the electric motor is only part of the heat generated.

And do you know what kind of power a normal heating device can heat and what power it requires?

Ordinary electric heaters are around 800 watts.

The air conditioner is even more thousands.

Of course, ordinary electric motors cannot be used to generate heat.

When the motor works normally, part of the pure work done by the current is converted into mechanical energy, and the other part is turned into heat energy, so the electric heat is only a part of the electric work, so d is correct

Therefore, d

1. The friction of the bearing generates heat.

2. The resistance of the coil generates heat.

3.The magnetic resistance of the iron core generates heat.

The main thing is the mechanical efficiency and the power factor of the motor, the total loss is about 20%, which basically becomes heat, so the motor shaft end is equipped with a heat dissipation blade.

The function of the motor is to convert electrical energy into mechanical energy, and it is inevitable that a part of the heat energy will be generated, assuming that the motor efficiency is 90%, then about 10% of the energy will be converted into thermal energy. Therefore.

A 1 kilowatt motor does not produce 1 kilowatt of heat when working.

Of course, there will be heat, copper loss, iron loss, mechanical loss, and stray loss.

Eventually, it will all be lost in the form of heat.

Otherwise, there will be no cooling methods such as air cooling and water cooling.

Haven't you ever touched a motor that has been running for a while, it often gets hot.

Conversion of electrical energy into mechanical energy.

When the stator windings are energized, a rotating magnetic field is generated to cut the rotor, and an electromotive force is induced.

As the rotor circuit is closed, an induced current is generated.

The induced current generates an electromagnetic force under the action of a magnetic field.

Push the rotor in motion.

Electromagnetic power is equal to input power minus stator loss (copper and iron consumption), and electromagnetic power minus rotor copper loss is equal to mechanical power.

The mechanical power minus the mechanical losses and additional losses is equal to the output power.

Heat will be generated, because the motor needs electricity to drive, and the motor must pass through the current in the windings of the motor to operate, but the winding of the motor is made of copper, and copper is not a superconductor (superconductors have not been found at room temperature), so according to the formula Q=I 2RT (wherein, Q represents the size of the heat, I 2 represents the square of the current, R represents the resistance of the conductor, and T represents the time of energizing), it can be seen that the larger the energizing current, the more serious the heating (high-power motors need fans to dissipate heat, The smaller the power is not needed), the greater the conductor resistance, the more serious the heating (this is the reason why the motor winding uses copper instead of aluminum, aluminum is cheaper than copper, but the resistance is greater than copper), the longer the power on time, the greater the heat generation (if the heat dissipation facilities are not good, the motor is not suitable for long-term work)!Even if the large motor dissipates heat (plus fan heat dissipation), the temperature is dozens of degrees!