Motor maintenance and repair knowledge book.

1、What is the motor?

A: The motor is a component that converts battery electric energy into mechanical energy to drive the wheels of electric vehicles to rotate.

2、What is the stator?

A: Brush or brushless motors do not rotate when working part. Hub type brush or brushless gearless motor motor shaft called stator, such motors can be called internal stator motor.

3、What is the rotor?

A: The part of brush or brushless motor that rotates when it works. Hub type brush or brushless gearless motor shell called rotor, such motors can be called external rotor motor.

4、What is called carbon brush?

A: Brush motor inside the top in the phase commutator surface, the motor rotation, the electrical energy through the phase commutator to the coil, because its main component is carbon, called carbon brushes, it is easy to wear. It should be regularly maintained and replaced, and cleaned up the carbon accumulation.

5、What is brush grip?

A: The mechanical guide groove that holds and keeps the carbon brush position inside the brush motor.

6、What is phase changer?

A: Inside the brush motor, there is a mutually insulated strip of metal surface, with the motor rotor rotation, the strip of metal alternately contact the positive and negative brushes, to achieve alternating positive and negative changes in the direction of the motor coil current, to complete the phase change of the brush motor coil.

7、What is phase sequence?

A: The arrangement order of brushless motor coils.

8、What is magnet?

A: Generally used to call the magnetic material of high magnetic field strength, electric car motors are using neodymium iron boron rare earth magnets.

9、What is brush motor?

A: When the motor works, the coil and commutator rotate, the magnet and carbon brush do not rotate, the alternate change of coil current direction is done by the commutator and brush that rotate with the motor. In the electric vehicle industry brush motor is divided into high speed brush motor and low speed brush motor. There are many differences between brush motor and brushless motor. From the name, we can see that brush motor has carbon brush and brushless motor has no carbon brush.

10、What is a brushless motor?

A: The controller provides DC power in different current directions to achieve alternate changes in the direction of the coil current inside the motor, and there are no brushes and phase changers between the rotor and stator of a brushless motor.

11、How does the motor achieve phase change?

A: When a brushless or brush motor is rotating, the direction of energization of the coil inside the motor needs to be changed alternately so that the motor can rotate continuously. Brush motor phase changer and brush together to complete, brushless motor controller to complete.

12、What is phase loss?

A: Brushless motor or brushless controller of the three-phase circuit, one phase can not work. Out of phase is divided into main phase out of phase and Hall out of phase. Performance for the motor jitter can not work, or rotating powerless and noisy. Controller working in the state of phase loss is very easy to burn.

13、What are the common types of motors?

A: The common motors are: brushed geared hub motor, brushed gearless hub motor, brushless gearless hub motor, brushless geared hub motor, side hung motor, etc.

14、How to distinguish from the type of motor is high and low speed motors?

A: A brush with gear hub motor, brushless with gear hub motor belongs to high speed motor; B brushless gear hub motor, brushless gear hub motor belongs to low speed motor.

15、How is the efficiency of the motor defined?

A: The efficiency of the motor is the ratio of the mechanical energy output by the motor to the electrical energy provided by the power supply. It is expressed by the letter "り".

16、How is the classification of brushless motor?

A: From the phase angle can be divided into two categories, that is, into 60 ° and 120 ° phase angle brushless motor; according to speed, can be divided into high-speed brushless motor and low-speed brushless motor; according to whether the motor has a position sensor to be divided into position sensor brushless motor and brushless motor without position sensor.

17、What is a brushless motor without position sensor?

A: For brushless motors without position sensor, the car must be pedaled up first, so that the motor has a certain rotation speed after the controller can identify the phase of the brushless motor, after which the controller can supply power to the motor. Because it can not achieve zero-speed start, so the use of few. But its because there is no sensor, all less a failure point, and its cost is much lower.

18、What is the approximate range of power consumption of brushless motor lug?

A: The power consumption of brushless motor lug is in the range of 6mA-20mA.

19、What is the voltage range of brushless motor lug?

A: The voltage range of brushless motor lug is generally in the range of 3-24V.

20、How high can the motor work normally in general? How high can the motor withstand at most?

A: If the measured temperature of the motor cover exceeds the ambient temperature by more than 25 degrees, it indicates that the temperature rise of the motor has exceeded the normal range, and the general temperature rise of the motor should be below 20 degrees. General motor coil is made of enameled wire winding, and enameled wire in the temperature higher than about 150 degrees its varnish will fall off because of high temperature, resulting in a short circuit of the coil. When the coil temperature is above 150 degrees, the motor shell shows a temperature of about 100 degrees, so if the shell temperature is based on the maximum temperature that the motor can withstand is about 100 degrees.

21、The temperature rise of the motor should be below 20℃, that is, the temperature of the motor end cover over the ambient temperature should be less than 20℃, but what is the reason for the motor to heat up more than 20℃?

A: The direct cause of motor heating is caused by high current. Generally, it may be caused by short circuit or open circuit of the coil, low efficiency of the motor in the magnet demagnetization, etc. The normal situation is that the motor runs at high current for a long time.

22、How to measure the phase angle of brushless motor?

A: Turn on the controller power supply, from the controller to the Hall component power supply, you can detect the phase angle of the brushless motor. The method is as follows: use the +20V DC voltage file of the multimeter, and the red pencil to +5V line, the black pencil to measure the high and low voltage of the three leads respectively (there is a trick on the usage of the red and black pencils here), according to the phase change table of 60° and 120° motor can be compared.

23、What will happen if the 60° brushless controller is used in 120° brushless motor? How about vice versa?

A: Both will lead to the phenomenon of phase loss, can not operate normally; but Tianjin Songzheng developed an intelligent brushless controller can automatically identify 60 ° motor or 120 ° motor, so that it can be compatible with two kinds of motors, making it easier to repair and replace.

24、What is the intuitive difference between brushed high-speed motor and brushed low-speed motor?

A. High-speed motor has an overrunning clutch (like a flywheel function), easy to turn in one direction, to turn in the other direction with great effort; low-speed motor two-way rotation are as easy. B. High-speed motor of the car rotating noise, low-speed motor rotation noise is smaller. Experienced people are easy to identify by ear.

25、How is the starting current of the motor defined?

A. Generally, the starting current of the motor is required not to exceed 2 to 5 times its rated current, which is an important reason why the current limit protection is done on the controller.

26、Why is the speed of the motor sold in the market getting higher and what is the impact?

A. Suppliers can reduce the cost of speed, the same low-speed motor, high speed coil turns less, but also save the silicon steel, the number of magnets is also less, the buyer believes that high speed is good. B. rated speed work, its efficiency remains unchanged, but in the low-speed area, the efficiency is obviously low, that is, the start is weak. C. low efficiency, the need to start with high current, the riding current is also high, the current limit requirements of the controller, the battery is also bad.

27、How to repair the abnormal heating of the motor?

A: The repair treatment method is generally to replace the motor, or maintenance.

28、The no-load current of the motor is greater than the reference table limit data indicates that the motor has a fault, what are the causes? How to repair?

A: the motor internal mechanical friction; coil local short circuit; magnet demagnetization; DC motor phase converter carbon accumulation. Repair treatment method is generally to replace the motor, or replace the carbon brush, clean up the carbon.

29. What is the maximum limit no-load current of various motors without fault?

Motor form Rated voltage 24V Rated voltage 36V Side hanging motor 2.2A 1.8A High-speed brushed motor 1.7A 1.0A Low-speed brushed motor 1.0A 0.6A High-speed brushless motor 1.7A 0.6A Low-speed brushless motor 1.0A 0.6A 1.0A 0.6A 1. Feeling of slow speed and stagnant weight when riding by human power

(1) The front brake or holding brake (up the brake) and the rotation part friction → adjust the front and rear brake and rotation parts clearance, both to make the rotation flexible, but also to ensure good brake braking performance.

(2)The chain is too tight→adjust the front and rear position of the rear axle

(3)The front and rear axle gears and center shaft parts and caps are too tight or the parts are worn out → Loosen the fasteners or replace the worn parts.

(4)The front and rear tires are under-inflated → tire inflation to full.

2, the battery is sufficient but the load situation two red lights on off

(1) the charger output voltage is low → according to the charger maintenance method to troubleshoot.

(2) short battery charging time → re-charge to extend the charging time.

(3)Battery pack or its single capacity decreases → troubleshooting according to the battery box maintenance method.

(4) electrode damage or poor contact → replace the electrode.

3、There is a feeling of stopping, fast and slow, powerlessness, etc. in driving

(1) seven-cell connection contact is bad → change the seven-cell wire.

(2) Hall power-off brake contact is poor → change the Hall power-off brake.

4、Battery is sufficient, the display light is fully lit, but the load hub rotation powerless

(1) Gear wear slippage → replace the gear.

(2) wheel motor winding part short circuit → replace the motor.

(3) bicycle assembly problems or parts wear → replace the vibration damping rubber.

5、The electric drive has irregular stopping

(1)Controller and electric wheel hub connector loosened or conductive bad → re-insert tight connector or replace the plug-in.

(2) wheel motor carbon brush and rotor contact is poor → according to the wheel maintenance method to troubleshoot.

6、Electric drive noise ringing

(1) wheel gear lack of oil → open the hub, apply gear grease.

(2) gear defective → replace the gear.

(3) Gear housing bearing damage → replace the bearing.

1, before disassembling the motor should first unplug the motor and controller leads, at this time, be sure to record the one-to-one correspondence between the color of the motor leads and the color of the controller leads. Before opening the motor end cover should be cleaned for the site to prevent debris being absorbed in the motor magnets. Make a good mark of the relative position of the end cover and hub. Note: Be sure to loosen the screws diagonally to avoid deformation of the motor housing. Motor rotor and stator radial clearance called air gap (air gap), the general motor air gap between 0.25-0.8mm, when the disassembly of the motor to exclude the motor fault, must be the original end cover marks for assembly, which can prevent the second assembly after the sweep phenomenon.

2, lubrication of the gears in the motor if the brush has a gear hub motor and brushless has a gear hub motor running noise began to become louder, or replaced the gears in the motor, the gears should be coated with grease on all tooth surfaces, generally use No. 3 grease or lubricant specified by the manufacturer.

3, motor assembly before assembling the brush motor, please check the elasticity of the spring inside the brush grip, check whether the carbon brush and brush grip are touching, check whether the carbon brush can reach the maximum stroke in the brush grip, pay attention to the correct positioning of the carbon brush and the phase changer to avoid jamming the carbon brush or brush grip. When installing the motor, first of all, the surface of the motor parts should be cleaned of impurities, so as not to affect the normal operation of the motor, and be sure to fix the hub body solid, so as not to be installed due to the strong attraction of the magnets, resulting in mutual impact and damage to the parts. Brushless motor is not difficult to repair, the first thing to determine whether the controller problem or motor. Controller is generally internal tube burnout with a hand turn very heavy motor, motor Hall burnout can start, <a tube below>. Of course, you can also use the multimeter measurement, the positive meter pole connected to the negative side of the motor Hall, the negative meter pole were connected to three signal lines normal for 500-800 Europe