The electric wheelchair is a necessary means of transportation in the life of every person with limited mobility. It is driven by a battery-powered motor and can be self-propelled, allowing users to move around more independently and easily. The quality of an electric wheelchair depends on the motor of the electric wheelchair. The better the power of the motor, the better the mobility of the electric wheelchair and the better the convenience of use.As a professional manufacturer of wheelchair motors, Yuen Long Technology has more than 20 years of manufacturing experience and a professional R&D team and has extensive knowledge of wheelchair motors. This article mainly introduces the types of wheelchair motors and their differences, and how to choose a good motor for a wheelchair.
According to the working mode of the motor, it can be divided into a brush motor and a brushless motor. According to the number of brushes and magnets, it can be divided into two-pole motors or four-pole motors.
The wheelchair brush motor is a rotating motor that contains a brush device that converts electrical energy into mechanical energy. When the motor is working, the coil and commutator rotate, but the magnetic steel and carbon brush does not rotate. The alternating current direction of the coil is changed by the commutator and brush that rotates with the motor. The wheelchair brush motor is the basis of all motors. It has the characteristics of fast starting, timely braking, smooth speed regulation in a large range, and a relatively simple control circuit.
a) Smooth speed change, almost no vibration;
b) Low-temperature rise and good reliability;
c) High-cost performance, so it is selected by more manufacturers.
a) The carbon brush is easy to wear, it is troublesome to replace, and the service life is short;
b) The operating current is large, and the motor magnet is easy to demagnetize, which reduces the service life of the motor and battery.
The wheelchair brushless DC motor is composed of a motor body and a driver and is a typical mechatronic product. The wheelchair brushless motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices are used to replace traditional contact commutators and brushes. Because the wheelchair brushless motor runs in a self-controlled manner, it will not add a start winding to the rotor like a synchronous motor that is started under heavy load under variable frequency speed regulation, nor will it cause oscillation and loss of step when the load changes suddenly. Therefore, the wheelchair brushless motor has the advantages of high reliability, no reversing sparks, and low mechanical noise.
a) Electronic commutation instead of traditional mechanical commutation, reliable performance, never wear, low failure rate, life expectancy is about 6 times longer than that of brushed motors, which represents the development direction of electric vehicles;
b) It is a static motor with a low no-load current;
c) High efficiency;
d) Small size.
a) There is a slight vibration when starting at a low speed. If the speed increases and the commutation frequency increases, the vibration will not be felt;
b) The price is high, and the controller requirements are high;
c) Resonance is easy to form because everything has a natural vibration rate. If the vibration frequency of the wheelchair brushless motor is the same as or close to the vibration frequency of the frame or plastic parts, it is easy to form a resonance phenomenon, but the resonance phenomenon can be reduced to a minimum by adjustment. Therefore, it is a normal phenomenon for electric vehicles driven by wheelchair brushless motors to sometimes make a buzzing sound.
There are two sets of brushes and magnets inside the wheelchair two-pole motor. The power of the battery will enter the motor (via the control module) and output in two positions of the two-pole motor. The wheelchair two-pole motor pulls more smoothly during very slow operation, which makes the two-pole motor an ideal choice for narrow indoor environments. The wheelchair two-pole motor is not suitable for electric wheelchair users who are too heavy or will drive on uneven terrain.
There are four sets of brushes and magnets inside the wheelchair four-pole motor. It has more torque than a wheelchair two-pole motor, so it can withstand uneven outdoor terrain and heavier load-bearing capacity.
1. Service life
Wheelchair brushless motors: Usually the service life is in the order of tens of thousands of hours, but the service life of brushless motors is also very different due to different bearings.
Wheelchairs with brush motors: Usually the brush motors need to be replaced after a period of use, otherwise it is easy to cause damage.
2. Use effect
Wheelchair brushless motor: usually digital frequency conversion control, strong controllability, from a few revolutions per minute to tens of thousands of revolutions per minute can be easily achieved.
Wheelchair brush motor: The old carbon brush motor generally works at a constant speed after startup, and the speed adjustment is not very easy. The series motor can also reach 20,000 rpm, but the service life will be relatively short.
3. Energy saving
Relatively speaking, the brushless motor of a wheelchair can be much more energy-saving than a series-excited motor controlled by frequency conversion technology.
Wheelchairs with brush motors need to replace the carbon brushes. If they are not replaced in time, the motor will be damaged and unable to operate. The wheelchair brushless motor does not require frequent replacement of carbon brushes, has a longer service life, and basically does not require routine maintenance.
The wheelchair brush motor is a traditional product with relatively stable performance. The wheelchair brushless motor is an upgraded product, and its live performance is better than that of a brush motor. However, its control circuit is more complicated, and the requirements for the aging and screening of components are stricter. Although the motor has a long life, the control circuit is prone to malfunctions. Therefore, the selection of brushless motors for wheelchairs must undergo rigorous reliability tests to ensure quality. However, with the continuous upgrading of technology, the technology of brushless motors for wheelchairs has become quite mature.
In the actual production process, because the brushed and toothed DC motor of the wheelchair is a high-speed motor, the teeth of the gear are small and easy to wear, but the force is large and the climbing ability is strong.
The wheelchair brushless motor saves two or three years of the trouble of changing carbon brushes during use. But in the process of controlling the wheelchair brushless motor, high precision is required.
1. Look at the appearance. The appearance is rough, the quality is definitely not much better.
2. Listen to the sound. Place it on flat ground, there should be no obvious vibration, and there should be no abnormal noise during no-load operation.
3. Look at the current. The no-load current is generally 15%-20% of the rated current. If it is too large, it means that the material or manufacturing process is not good.
4. Look at the temperature rise. When there is no load, the temperature rise should be small. In the rated state, the temperature rise should not be too fast and should be within the calibration range.
5. According to the load capacity, the motor allows a long-term overload of 20%. In this case, the temperature rises and operating conditions should be within a reasonable range.
In short, whether it is a wheelchair brush motor or a wheelchair brushless motor, there is not much difference for an electric wheelchair. For users, the biggest difference is that a wheelchair brushless motor with the same power is slightly smaller in volume and weight than a brush motor. Therefore, when purchasing an electric wheelchair, choose according to your actual needs.
As a professional wheelchair brushless motor manufacturer, Nanjing Yuanlang Electronic provides high-quality wheelchair brushless motors. If you have any needs, please contact us immediately.