As a necessary household appliance, washing machine is believed to be equipped in everyone's home. The development of washing machines so far, there have been a variety of models classification. According to different ways of distinguishing, it can be divided into different types of washing machines. Today, we will talk about an important part of washing machines - the motor. See what different categories it has and how they differ from one another.
The washing machine can be divided into variable frequency and fixed frequency washing machines according to whether the motor speed is variable. The intermediate frequency is the frequency of the induced electric field in the motor, which is simply the motor speed.
The frequency conversion washing machine can switch different speeds according to the washing program, water consumption, and laundry weight, which can not only reduce the damage of the washing machine inner drum to the clothes, but also save electricity, water and electricity.
A fixed-frequency washing machine means that as long as it is started, the motor speed will remain unchanged. The fixed-frequency washing machine can wash and dry clothes in place.
The washing machine can also be divided into direct drive and belt drive washing machines according to the connection method of the motor and the drum.
The direct-drive washing machine is directly connected to the motor and the drum, which has high efficiency, low vibration, low noise, and relatively high price.
Belt drive means that the kinetic energy generated by the motor of the washing machine is transmitted to the drum of the washing machine through multiple belts, and the vibration and noise are relatively large.
To sum up, variable frequency, fixed frequency and direct drive, belt-driven washing machines are mutually inclusive and intersecting.
For example, in inverter washing machines, direct-drive washing machines generally use DD motors, and belt-driven washing machines generally use BLDC motors and three-phase induction motors.
There are more belt-driven washing machines in fixed-frequency washing machines, and most of them use series motors.
The performance order of these three motors is generally: DD>BLDC>Series motor.
Be careful when purchasing!
If they are all BLDC motors, it depends on the energy efficiency level. The energy efficiency level of level 1 is relatively good, and the energy consumption of level 2 and level 3 decreases gradually.
If you want to buy a washing machine, you can look at more than fixed frequency and variable frequency! It also depends on the speed of the washing machine and the drainage method.
The higher the speed, the cleaner the laundry and the more thorough the dehydration.
The drainage methods are divided into upper drainage and lower drainage.
The upper drainage is to lift the waste water through the pump of the machine and then discharge it, and the foam, impurities and sewage in the cylinder are all discharged at one time, so the waste water in the washing machine will be discharged more cleanly, and the discharged water has the opportunity to be stored after Secondary recycling.
The upper drainage does not have many requirements for the placement position, and it is not limited by the height of the drainage pipe, and can also be placed in places without floor drains. However, since electricity is used to drain water through a drain pump, it consumes more electricity than down draining.
The lower drainage is drained by natural gravity, and the water pump is not needed in the process, so the power consumption is small. However, the lower drainage has the disadvantage of unclean drainage. Often, some waste water will be left in the bottom part of the washing machine, and long-term accumulation is easy to breed bacteria. Therefore, it is necessary to clean the drainage pipe of the washing machine regularly.
The under-draining washing machine must be placed near the floor drain, so that the waste water can be directly discharged into the floor drain. Therefore, the floor drain of the under-draining washing machine should not be 10 cm higher than the washing machine. If it is too high, it will not be able to drain normally.
The difference between inverter motor and ordinary motor of drum washing machine The characteristics of inverter washing machine motor
2016/05/24 17:34:09 Source: Fang Tianxia Views (9436)
[Abstract] Inverter washing machine products have the characteristics of energy saving, ultra-low noise, variable water flow, high dehydration speed, etc. The function of inverter washing machine is that the mute effect is obvious. The speed can be adjusted appropriately according to the weight of the clothes, etc., so as to effectively reduce the sound and vibration. So, what is the difference between the frequency conversion motor of the drum washing machine and the ordinary motor? What are the characteristics of the frequency conversion washing machine motor? Let's take a look at it together.
The frequency conversion washing machine products have the characteristics of energy saving, ultra-low noise, variable water flow, high dehydration speed, etc. The functional characteristic of the frequency conversion washing machine is that the mute effect is obvious. The speed can be adjusted appropriately according to the weight of the clothes, etc., so as to effectively reduce the sound and vibration. So, what is the difference between the frequency conversion motor of the drum washing machine and the ordinary motor? What are the characteristics of the frequency conversion washing machine motor? Let's take a look at it together.
First, the difference between the inverter motor and the ordinary motor of the drum washing machine
The ordinary motor drives the washing machine to rotate through the transmission belt, and the frequency conversion motor directly drives the washing machine to rotate through the motor. The frequency conversion motor has low noise and small vibration. The ordinary motor makes a loud rumbling sound when washing clothes, but the frequency conversion motor is more expensive.
Second, the characteristics of the frequency conversion washing machine motor
(1) Electromagnetic design
For ordinary asynchronous motors, the main performance parameters considered in redesign are overload capacity, starting performance, efficiency and power factor. For variable frequency motors, since the critical slip is inversely proportional to the power supply frequency, it can be started directly when the critical slip is close to 1. Therefore, overload capacity and starting performance do not need to be considered too much, but the key problem to be solved is how to improve the motor to Adaptability to non-sinusoidal power supplies. The way is generally as follows:
1. Reduce the stator and rotor resistance as much as possible. Reducing the stator resistance can reduce the copper loss of the fundamental wave to make up for the increase in copper loss caused by higher harmonics.
2. In order to suppress the high-order harmonics in the current, the inductance of the motor needs to be appropriately increased. However, the leakage reactance of the rotor slot is larger, the skin effect is also larger, and the copper loss of high-order harmonics is also increased. Therefore, the size of the leakage reactance of the motor should take into account the rationality of impedance matching in the entire speed regulation range.
3. The main magnetic circuit of the variable frequency motor is generally designed to be unsaturated. First, considering that higher harmonics will deepen the magnetic circuit saturation, and second, considering that at low frequencies, in order to increase the output torque, the output voltage of the inverter should be appropriately increased.
(2) Structural design
When designing the structure again, the influence of the non-sinusoidal power supply characteristics on the insulation structure, vibration, noise cooling method, etc. of the variable frequency motor is mainly considered, and the following issues are generally paid attention to:
1. Insulation grade, generally F grade or higher, strengthen the insulation strength to ground and turns, and consider the ability of insulation to withstand impulse voltage.
2. For the vibration and noise of the motor, the rigidity of the motor components and the whole should be fully considered, and the natural frequency should be increased as much as possible to avoid resonance with each force wave.
3. The cooling method generally adopts forced ventilation cooling, that is, the main motor cooling fan is driven by an independent motor.
4. Measures to prevent shaft current, bearing insulation measures should be adopted for motors with a capacity exceeding 160KW. Mainly, it is easy to produce asymmetry of the magnetic circuit, and also produces shaft current. When the currents generated by other high-frequency components act together, the shaft current will increase greatly, resulting in damage to the bearing, so insulation measures are generally taken.
5. For constant power variable frequency motor, when the speed exceeds 3000/min, special grease with high temperature resistance should be used to compensate for the temperature rise of the bearing.
