A brushless DC motor water pump

Abstract

The invention provides a brushless DC motor water pump. It includes a driving circuit, which is composed of a main control chip, a Schottky diode, a voltage transient suppression diode, a main absorption capacitor, a discharge resistor, and a pull-up resistor; the anode terminal of the Schottky diode is connected to the positive port of the power supply, and the Schottky diode The cathode end of the diode is simultaneously connected to the cathode end of the voltage transient suppression diode, the main absorption capacitor, the discharge resistor, the pull-up resistor and the positive port of the power supply of the main control chip; the anode end of the voltage transient suppression diode and the main absorption capacitor The other end of the discharge resistor is connected to the negative terminal of the power supply; the duty cycle speed regulation command input pin of the main control chip is connected to the other end of the pull-up resistor; the motor phase winding connection pins of the main control chip are respectively connected to the three-phase The three U / V / W windings of the brushless motor are connected; the three phase windings of the brushless motor adopt a star connection method. The invention improves the efficiency of the water pump, reduces noise and vibration amplitude, and improves the stability of the water pump when used.

Description

technical field [0001] The invention belongs to the technical field of home appliances, and in particular relates to a brushless DC motor water pump. Background technique [0002] The air conditioner has the ability to generate cold air and send air to the room. During the heat exchange process of the indoor hot air, condensed water will be generated on the heat exchanger. Therefore, the air conditioner is generally equipped with a drainage pump, mainly to avoid natural drainage. When it is not smooth, it is convenient to discharge the condensed water. At present, shaded pole drainage pumps are generally used for air conditioner drainage pumps, but the efficiency of shaded pole drainage pumps is low, generally around 12%, and it will also produce adverse effects such as loud noise and large pump vibration. [0003] At the same time, the driving circuit of conventional water pumps still has the following defects: (1) The conventional motor driving circuit is designed and con...

AI Technical Summary

Problems solved by technology

At present, shaded pole drainage pumps are generally used for air conditioner drainage pumps, but the efficiency of shaded pole drainage pumps is low, generally around 12%, and it will also produce adverse effects such as loud noise and large vibration of the pump.

[0003] At the same time, the driving circuit of conventional water pumps still has the following defects: (1) The conventional motor driving circuit is designed and connected with a single main control chip + 6 external MOSFETs + external Gate Drive circuit. The device selection is more, the connection is complicated, and the reliability of the entire circuit control system is low; (2) the conventional MOSFET manufacturing process, its on-resistance is generally above 0.5 ohms, and the outside of the chip needs to be connected to a large-area metal heat sink for heat dissipation ; (3) The conventional brushless motor adopts 120-degree conduction technology, the conduction and switching of the motor phase winding are sudden, the current waveform is similar to the square wave waveform, and its current impact and harmonic components are very large, giving the motor (4) Conventional brushless motor drive circuits generally do not take into account the actual application of power supply reverse connection and EMI abnormal voltage spikes. The designed circuit is often caused by operator wiring errors, human body static electricity, EMI interference, etc., lead to premature failure of the circuit, which is also an important reason for the low reliability of many conventional products

[0004] Generally speaking, due to the above-mentioned technical problems in the existing water pumps, the efficiency of the existing water pumps is low, the noise is large, the vibration is large, and the performance is unstable.

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