Electric vehicle motor 205-16 inches

Product Introduction: Specification and Model: 22-27 (Stacked) Voltage: 48V-60V Speed: 350R-500R Wheel Type: 16-2.5/2.15 Assembly Size: 160mm Color: Black/Champagne/Cream/Gold

The characteristic of brushless DC motors is brushless, using semiconductor switching devices (such as Hall elements) to achieve electronic commutation, that is, replacing traditional contact commutators and brushes with electronic switching devices. It has the advantages of high reliability, no commutation sparks, and low mechanical noise.

The position sensor converts the current of the stator winding in a certain order according to the change in rotor position (i.e. detects the position of the rotor magnetic pole relative to the stator winding and generates a position sensing signal at a determined position, which is processed by the signal conversion circuit to control the power switch circuit and switch the winding current according to a certain logical relationship).

(1) Long lifespan, maintenance free, and high reliability. In brushed DC motors, due to the high motor speed, the brushes and commutators wear out quickly, and generally need to be replaced after about 1000 hours of operation. In addition, the technical difficulty of its reduction gearbox is relatively high, especially the lubrication problem of the transmission gear, which is currently a major challenge in existing brush solutions. So brushed motors have problems such as high noise, low efficiency, and susceptibility to malfunctions. Therefore, the advantages of brushless DC motors are very obvious.

(2) High efficiency and energy-saving. Generally speaking, due to the absence of mechanical commutation friction losses, gearbox consumption, and speed control circuit losses in brushless DC motors, the efficiency can usually be higher than 85%. However, considering the highest cost-effectiveness in actual design, in order to reduce material consumption, it is generally designed at 76%. The efficiency of brushed DC motors is usually around 70% due to the consumption of gearboxes and overrunning clutches.

1. The no-load current of the motor is high

When the no-load current of the motor is greater than the limit data, it indicates that the motor has malfunctioned. The reasons for the high no-load current of the motor include high mechanical friction inside the motor, local short circuit of the coil, and demagnetization of the magnetic steel. We will continue with the relevant testing and inspection items to further determine the cause or location of the malfunction.

If the no-load/load speed ratio of the motor is greater than 1.5, turn on the power and rotate the handle to make the motor run at high speed for more than 10 seconds without load. After the motor speed stabilizes, measure the maximum no-load speed N1 of the motor at this time. Under standard test conditions, drive for more than 200m and start measuring the maximum load speed N2 of the motor. The no-load/load ratio=N2 ÷ N1.

When the no-load/load speed ratio of the motor is greater than 1.5, it indicates that the demagnetization of the motor's magnetic steel is quite severe, and the entire set of magnetic steel inside the motor should be replaced. In the actual maintenance process of electric vehicles, the entire motor is usually replaced.

2. Motor overheating

The direct cause of motor heating is due to high current. The relationship between motor current I, input electromotive force E1, induced electromotive force (also known as back electromotive force) E2 caused by motor rotation, and motor coil resistance R is: I=(E1-E2) ÷ R. An increase in I indicates a decrease in R or a decrease in E2. The decrease in R is usually caused by a short circuit or open circuit in the coil, while the decrease in E2 is usually caused by demagnetization of the magnetic steel or a short circuit or open circuit in the coil. In the maintenance practice of electric vehicles, the method to deal with motor overheating and malfunction is generally to replace the motor.

3. There is mechanical collision or noise inside the motor during operation

Both high-speed and low-speed motors should not experience mechanical collisions or discontinuous irregular mechanical noise during load operation. Different forms of motors can be repaired using different methods.

4. The driving range of the whole vehicle is shortened, and the motor is weak

The reasons for short driving range and weak motor (commonly known as motor fatigue) are quite complex. But after excluding the above four types of motor faults, generally speaking, the short driving range of the vehicle is not caused by the motor, which is related to the attenuation of battery capacity, insufficient charging of the charger, controller parameter drift (PWM signal not reaching 100%), etc.

5. Brushless motor phase loss

Brushless motor phase loss is generally caused by damage to the Hall element of the brushless motor. We can use a comparative method to determine which Hall element is faulty by measuring the resistance of the output lead of the Hall element relative to the Hall ground and the lead relative to the Hall power supply.

To ensure the accuracy of the motor commutation position, it is generally recommended to replace all three Hall elements simultaneously. Before replacing the Hall element, it is necessary to determine whether the phase algebraic angle of the motor is 120 ° or 60 °. Generally, the placement of the three Hall elements of a 120 ° phase angle motor is parallel. And for a 60 ° phase angle motor, one of the three Hall elements is placed in a flipped 180 ° position.