Introduction to the application of electric motors in microwave ovens
Microwave ovens are common household appliances in daily life, and motors are also used. Household microwave ovens are kitchen appliances that use electromagnetic waves with a frequency of 2450 MHz to heat food. The working principle of the microwave oven is that during the movement of the electrons emitted from the pole of the magnetron to the anode, the permanent magnet in the magnetron generates an axial magnetic field, so that the electrons move in a cycloid motion under the dual action of electric field force and magnetic field force. It oscillates in the resonant cavity to generate 2450MHz microwaves, which are input into the oven cavity through the waveguide to heat food.
Motor for blower
The magnetron generates high heat when it is working, and it needs a blower to cool down and lower the temperature to work normally. The blower consists of a single-phase shaded pole asynchronous motor and a fan. The blower not only cools the magnetron, but also cools the transformer, and directs hot air into the oven cavity to heat the food, which improves the utilization rate of heat energy and also discharges steam and smoke from the oven cavity.
The function of the stirrer is to make the microwave field in the oven cavity uniform, so that the food is evenly heated.
The stirrer is made of an alloy plate with good electrical conductivity and high strength. It is driven by a single-phase shaded-pole asynchronous motor to rotate. The reflection angle of the microwave is constantly changed to improve the distribution of the microwave field in the oven cavity, thereby making food Heat evenly.
Some microwave ovens also have a small exhaust fan inside the cavity to exhaust and stir.
Motor for turntable
Some microwave ovens do not use a stirrer, but are equipped with a turntable at the bottom of the cavity. The turntable drives the food to rotate, relatively changing the distribution of the microwave field, so that the food itself is evenly heated. The turntable is driven by a single-phase permanent magnet synchronous motor through gear reduction, and the general speed is 5-10r/min.
Motor for timer
Most microwave ovens use electric timers and single-phase permanent magnet synchronous motors with reducers.
Motor for power controller
The power controller and timer of some microwave ovens share a single-phase permanent magnet synchronous motor drive. The power controller knob drives the camshaft and other mechanisms to control the closing of the power controller switch, providing different levels of power selection.