Structural composition of electric bikes
1: Brushless toothless motor:
● Rotor winding: The magnetic field generated after energization interacts with the magnetic field of the stator magnet to drive the rotor to rotate. The rotor winding is connected to the commutator segments and connected to the external circuit through the commutator and brushes. The winding is wound on the coil bracket, and the number of slots on the bracket is generally 39 to 57.
● Stator magnets: bonded to the defined support body, usually 5 to 7 pairs. Its function is to generate sufficient magnetic field strength in the air gap between the motor rotor and the stator, and interact with the magnetic field generated by the rotor winding after energization. Produces torque to drive the motor rotor to rotate.
● Brush: A brushed motor is equipped with 1 to 2 pairs of brushes, which can be divided into positive brushes and negative brushes according to the polarity of the brush output. The brushes are pressed against the commutator segments under the action of the elastic force of the brush springs. The brush cross-section is trapezoidal or rectangular.
●Commutator: It consists of multiple copper commutator segments with trapezoidal end faces evenly distributed in the circumferential direction along the commutator bracket plate. In order to prevent short circuit between commutator segments, mica is used to insulate the commutator segments.
● Brush holder: There are 2 or 4 brush boxes, which are used to place the brushes and guide the movement of the brushes. The cross-section of the brush box is mostly trapezoidal, and some are rectangular. When installing, please note that there are two brush lead terminals on the other side of the brush holder, one is the positive pole and the other is the negative pole. If installed incorrectly, the motor will reverse.
2: Brushless toothless motor: mainly composed of rotor magnets, stator windings, bearings and left and right side covers.
● Rotor magnet: Use adhesive to fix the magnet and rotor.
● Stator winding: A three-phase winding is formed by being embedded in the slots in the winding support body in a certain pattern. The three-phase windings are often connected in star connection. The function of the winding is to generate a sufficient magnetic field in the air gap between the motor rotor and the stator after being energized, and interact with the permanent magnets to generate torque to drive the motor to rotate.
3: Brush-toothed motor: The brushes are used as the two contacts of the motor power supply, and the speed control handle and controller are used to control the motor, and the stepless speed change is achieved through the secondary reduction of the gear and the overrunning clutch. The reduction gear of this brushed and toothed motor has high strength, good wear resistance, and low repair rate.
Brushed and toothed motors are not hub-type motors and are composed of a rotor disc armature, magnets, commutator, brushes, reduction mechanism, ratchet collector, etc.
The brushed and toothed motor is a high-speed motor, that is, through the gear reduction mechanism, the motor speed is reduced and the torque is increased (the speed should be maintained at 3600r/min). The characteristics are as follows:
①: This type of motor is decelerated through gears, is powerful when starting, and has strong climbing ability.
②: The life of the motor and battery is short. Since the motor hub is closed, it is difficult for users to perform daily maintenance.
Exhaustion of lubricating oil will lead to increased gear wear due to poor lubrication, increased mechanical noise, and increased current usage, ultimately affecting the motor and battery. service life.
● Rotor disc armature: It is installed in the motor hub and is an iron-core rotor. The enameled wire is wound into the required shape, the taps are sorted out and reliably welded to the commutator lugs, and finally shaped with resin glue. , the reinforced seal becomes the required armature. It has the characteristics of light weight, easy starting, large torque and so on.
●Stator magnets: arranged in S and N grades along the circumferential direction.
● Commutator and brushes: The commutator is surrounded by many commutator segments.
The coils of the armature winding are connected to the commutator segments in a certain order. The DC power outside the motor reaches the armature winding through the brush and commutator. The magnetic field generated by the armature winding interacts with the stator magnet to generate torque to drive the armature to rotate.
The motor is equipped with two brushes. The brushes are divided into positive brushes and negative brushes according to the polarity of the input terminal. The brushes are pressed against the commutator under the action of the brush spring, and the brush box is fixed on the commutator. On the insulating board.
● Reduction mechanism: It reduces the speed output by the rotor disc armature, increases the torque, and drives the electric bicycle forward.
The principle is that the rotor disc armature rotates under the action of the magnetic field force, and drives the main gear to rotate through the elastic assembly relationship. After the main gear obtains torque, it drives the large gear on the intermediate gear to rotate through the gear meshing relationship. Due to the The number of teeth is greater than that of the driving gear, so the intermediate gear can obtain low speed and high torque, completing a deceleration task. The intermediate gear is composed of a large gear and a small gear through a square key, so the small gear on the intermediate gear gets a large torque, and then transmits the torque to the driven gear. Since the number of teeth on the driven gear is greater than that on the intermediate gear The pinion has a large number of teeth and completes the secondary reduction task, so the reduction mechanism is a secondary reduction. As a result, the passive gear gets powerful torque.
● Ratchet clutch: It is a one-way clutch, consisting of an inner race, pawl spring, pawl, retaining ring and passive gear.
The principle is that when the passive gear drives the internal teeth on its side to rotate, under the action of the pawl spring, the working part of the pawl is wedged between the internal teeth of the outer race in the passive gear, so the torque of the passive gear is transmitted to the inner seat through the ratchet teeth. Because the inner race and the side cover of the motor are fixed as a whole through bolts, when the armature rotor does not output power, the wheel drives the inner race to rotate. At this time, the pawl has no torque on the outer race in the passive gear, only a slight The friction force in the opposite direction, so when the main bracket of the electric bicycle is supported to rotate the rear wheel forward, you can vaguely hear the "clattering" friction sound of the pawl and the inner teeth of the outer race on the driven gear. At this time, the clutch is in the disengagement state. state. When turning the motor shaft, the resistance to rotation in one direction is small and the resistance to rotation in the other direction is large (this is a simple way to judge whether the ratchet clutch is normal). So it drives the wheel to turn.
4: Dual-core magnetic king brushless toothed motor: a new high-torque motor.
● Rotor: There is a long keyway in the inner hole of the rotor to combine with the spindle. Four magnets are embedded around the rotor. The N and S poles of the magnets are evenly distributed around the rotor. In order to prevent the depolarization effect, pole shoes made of soft magnetic material are added to the ends of the magnets. The pole shoes also prevent the magnets from falling off. .
● Stator: It is used to generate a magnetic field after the winding is energized. It is mainly composed of the stator core and the stator winding. It is located on the left reduction box.
The stator core is made of silicon steel sheets, with 12 slots on it, which are used to place three-phase stator windings. Each phase stator winding is placed in the corresponding stator slot to form a three-phase symmetrical winding to ensure that the three-phase electromotive force interacts with each other. is a phase angle of 120 degrees. Install slot insulation in the stator slot to ensure the insulation performance between the stator winding and the stator core. After the stator winding is assembled, it must be dipped in insulating paint to further improve the insulation performance.
● Overrunning clutch: It is a one-way clutch, consisting of a needle bearing, a star wheel seat combination, and a clutch gear. The clutch is installed on the steel sleeve pressed into the left box through a needle bearing. The star wheel seat assembly is set on the clutch gear. The inner ring star wheel seat is mounted on the motor shaft through splines.
● Reduction mechanism: A two-pole gear reducer is added between the motor main shaft and the rear wheel. The reduction mechanism is installed in the motor reduction box and consists of a main shaft, an intermediate gear, a countershaft, an overrunning clutch gear (output gear), etc.
5: New electric motor:
Brushless motor without position sensor:
Since there is no need to install a sensor to detect the running position of the motor, external force must be used to start the motor when starting. When the motor has a certain speed, the controller can identify the phase of the brushless motor, and then the controller starts to supply power to the motor windings so that the motor can work normally. Since motors without position sensors cannot start at zero speed, they are currently rarely used on electric bicycles. Due to the omission of position sensors, failure points are reduced and costs are reduced.
● Dual-core strong magnetic motor: This motor generates two kinds of energy, mechanical energy and strong magnetic energy after being energized, and allows the two energies to organically combine and interact with each other. It automatically supports and converts energy during the working process, making the motor's climbing performance and Perfect combination of operating speed. Features are as follows:
① Fully enclosed, live oil lubrication: To solve the adverse effects that may have been caused by high-speed dry rotation of gears in the past, the principle of steel gears and fully sealed live oil lubrication is used to solve previous problems.
② Split operation: A split combination of motor and aluminum wheel is used. In the past, the motor and aluminum wheel were integrated, which would cause losses due to the deformation of the aluminum wheel. Now, split operation does not affect the work of the motor even if the aluminum wheel is deformed.
③Strong climbing and strong power: Now even starting on a high slope of more than 30 degrees has no effect.
④Fashionable style and low noise: It adopts three-dimensional fully sealed manufacturing to solve the problem of large noise. The new electric motor can make the vehicle more complete.
⑤ Comes with clutch. Longer mileage: comes with a clutch that can be automatically disassembled. It solves the problem of poor overload capacity of direct drive, allowing the battery to be used for a longer period of time, thus extending the cruising range of the vehicle.
● Digital variable frequency generator: Features:
① Using electric energy recovery control technology, when the electric motor has no output power while the electric bicycle is driving, the electric motor is in a power generation state and the generated energy is recharged into the battery. This can increase the cruising range of the electric bicycle by 10% to 50%.
②Strong power. During starting or driving, the control system can automatically adjust the control current according to external driving resistance (such as wind force, load, etc.) to achieve the goals of fast starting, power saving, and strong climbing ability.
