What is a brushless direct drive pump?

Brushless DC Pump (Brushless DC Pump) is a machine that uses DC 4.5V to 24V to drive a brushless motor to run, and the rotation of the brushless motor drives the rotation of the impeller, thus increasing the pressure of the liquid to achieve the effect of transferring the liquid.

A Brushless DC water pump (magnetic isolation pump) consists of several parts: pump body (isolation parts), motor stator, shaft, bearing, and rotor water lobe (magnet and impeller).

Magnet (NdFeB permanent magnet)

The permanent magnet made of rare earth permanent magnet material has a wide working temperature range (-45-400℃), high coercivity, suitable anisotropy in magnetic field direction, and no demagnetization when the same poles are close to each other.

Isolation parts

When a metal isolation sleeve is used, the isolation sleeve is in a sinusoidal alternating magnetic field, and an eddy current is induced in the cross-section perpendicular to the direction of the magnetic force lines and converted into heat. The expression of eddy current is: where Pe – eddy current; K – constant; n – rated speed of the pump; T – magnetic transmission torque; F – pressure in the isolation sleeve; D – internal diameter of the isolation sleeve; a material’s resistivity; – tensile strength of the material. When the pump is designed, n and T are given by the working condition, to reduce the eddy current can only be considered from F and D, etc. The selection of high resistivity, high strength non-metallic materials for the isolation sleeve is very effective in reducing eddy currents.

Shaft

As the brushless DC diaphragm isolation pump works by driving the rotor through the energized coil, the rotation To keep the rotor rotation smooth and noisy, the high-performance ceramic shaft is used with the shaft sleeve, which can achieve high precision and effectively reduce the rotational resistance and noise.

Sliding bearing

Brushless pump sliding bearing materials are engineering plastic steel (POM) or ceramic. Since plastic steel (POM) and ceramics have good heat resistance, corrosion resistance, and friction resistance, the sliding bearings of magnetic pumps are mostly made of engineering ceramics. Since engineering ceramics are brittle and have a small expansion coefficient, the bearing clearance must not be too small to avoid shaft-holding accidents.

Since the sliding bearing of the magnetic pump is lubricated by the medium it conveys, different materials should be used to make the bearing according to other mediums and working conditions.

How does a brushless direct pump work?

Brushless DC magnetic drive pumps have a magnet and impeller injection molded into one piece to form the rotor of the motor, a direct injection molded sleeve in the middle of the rotor, which is fixed in the casing by a high-performance ceramic shaft, and the stator and circuit board part of the motor is sealed in the pump body by epoxy resin glue, and there is thin wall isolation between the stator and rotor, so there is no need to match the traditional mechanical shaft seal, thus it is completely sealed. The torque of the motor is generated by energizing the coil on the silicon steel sheet (stator) to produce a magnetic field that drives the permanent magnet (rotor). The magnets are magnetized in n (n is an even number) steps so that the magnet parts form a completely coupled magnetic system with each other. The magnetic energy of the magnetic system is lowest when the magnetic poles generated by the stator coil are opposite to the magnetic poles of the magnet, i.e. the displacement angle Φ=0 between the two poles; the magnetic energy of the magnetic system is highest when the poles are rotated to the same pole, i.e. the displacement angle Φ=2π/n between the two poles. After removing the external force, the magnetic force will restore the magnet to the state of lowest magnetic energy because the magnetic poles of the magnetic system repel each other. So the magnet produces motion and drives the magnetic rotor to rotate.

Brushless DC pumps are electronically commutated without the use of carbon brushes. Both the magnet rotor and the stator silicon steel sheet have multi-stage magnetic fields, and when the magnet rotor rotates at an angle relative to the stator it will automatically change the magnetic pole direction so that the rotor always maintains the same level of repulsion, thus making the brushless DC magnetic isolation pump have a high speed and efficiency.

The stator and rotor of the magnetic isolation pump are completely isolated, which completely avoids the liquid leakage problem of the traditional motorized brushless DC pumps. And it can be used completely submerged and completely waterproof, which effectively improves the service life and performance of the pump.

Advantages of brushless direct drive pump

1. Long life, no maintenance, small size and high efficiency, low power consumption.
2. Excellent design structure: pump head and motor rotor cavity connection, motor rotor cavity, and motor stator completely isolated, so that completely waterproof and leak-proof and high efficiency of the motor pump
3. Safety and health, environmental protection, and energy saving (because it is brushless is electronically controlled commutation solid no spark generation, and no carbon brush dust pollution).
4. The shaft of the pump adopts a high-performance ceramic shaft, high precision, good wear resistance, and extremely low sound, and can be used for water bed circulation, water bed heating, etc.
5. The three-phase DC water pump can realize PWM speed regulation, analog signal input speed regulation, and potentiometer manual speed regulation, which can realize the adjustment of head and flow rate.
6. The three-phase brushless water pump has impeller rotor jamming protection, reverse connection protection, overload protection, and overcurrent protection.
7. Three-phase brushless water pump, control for soft start, no shock, small start power consumption.
8. The pump can be fully submersible or non-submersible (the installation position can be lower than the liquid surface)
9. Can be customized according to user requirements and designed according to customer requirements
10. The three-phase brushless motor can withstand a high temperature of 100 degrees.

Areas of Use for this brushless pump:

1. The automotive industry: for car engines in the winter below minus 40 degrees engine cold start, fuel engine antifreeze high temperature 120 degrees circulation heat dissipation, electric cars, electric motorcycle water circulation heat dissipation.
2. Solar photovoltaic products: solar water pump is to use solar panels to directly drive the pump work, solar water pump has three major functions:

(1) energy saving, compared with ordinary DC brush water pump.
(2) Energy-saving, 35% more energy-efficient than ordinary DC brush water pump.

(3) Soft start function, the power can be started normally within 1W.

(4) Over-voltage protection function can be easily set. 3.

Food industry: mainly used in dishwashers, coffee makers, and drinking fountains, the pump shell can choose special food-grade high-temperature resistant materials, and the pump can work continuously and normally more than 100 degrees. Can reach food grade.

4. Household products: aquarium, fountain, foot bath, shower, plumbing mattress, computer water cooling system, etc.; DC brushless water pump has the characteristics of low noise, long life, and good pressure boosting effect, which can fully meet the above requirements.
5. Machinery and chemical industry: machine tool equipment water circulation heat dissipation, chiller circulation heat dissipation, sewage purification treatment, and other industries.

Additional information

1. Use a 12V or 24V DC transformer to supply power.
2. For the positive and negative power lines of the pump, the red line is positive when the black line is negative (if it is another line, it will also be marked positive and negative poles, please check the attached manual for details).
3. Connect the pump power line positive and negative correctly so that the pump can start and run normally.
4. Please try to put in clean water to avoid solid objects entering the pump and causing a blockage.
   5. Please do not drop and smash the product, which will affect the performance condition of the pump.
5. It is very easy to use the pump, please read the instruction carefully. If you have any questions or problems, please feel free to contact us.
6. When the driven parts of the magnetic actuator operate under overload, the driven parts of they magnetic actuator will slip on the shaft, effectively protecting the motor.

2. When the pump is running, a small amount of liquid must be used to flush and cool the ring gap area between the inner magnetic rotor and the isolation sleeve, and the frictional side of the sliding bearing. The flow of coolant is usually 2%-3% of the pump design flow. The ring gap area between the inner magnetic rotor and the isolation sleeve generates high heat due to the eddy current. When the cooling lubricating fluid is not enough or the flushing hole is not smooth or blocked, it will cause the medium temperature to be higher than the working temperature of the permanent magnet so that the inner magnetic rotor will gradually lose its magnetism and make the magnetic drive fail. When the medium is water or water-based liquid, the temperature rise of the ring gap area can be maintained at 3-5℃; when the medium is hydrocarbon or oil, the temperature rise of the ring gap area can be maintained at 5-8℃.