Permanent Magnet on Synchronous Drive Motor

In recent years, permanent magnet materials have developed rapidly, and there are many kinds of permanent magnet materials.

The most common types are ferrite permanent magnets, Al-Ni-Co permanent magnets, and Nd-Fe-B rare earth permanent magnets.

The outstanding advantage of ferrite permanent magnet material is that it does not contain rare earth elements.

Synchronous Drive Motor

And cobalt, nickel, and other precious metals, low price, simple manufacturing process, high coercivity, strong anti-magnetic ability, low density, lightweight. However, the ferrite permanent magnet material is hard and brittle, and it can not be processed electronically. The motor produced is of low power and low efficiency.

Aluminum-nickel-cobalt permanent magnets are characterized by the low-temperature coefficient, high residual magnetic induction, and low coercivity. They are easy to be magnetized and demagnetized, but contain cobalt, which is a precious metal, so the price is very high.

Neodymium rare earth permanent magnets have become the main force of permanent magnets because of their excellent magnetic properties, and their magnetic properties far exceed those of ferrite, Al-Ni-Co, and other magnetic materials. Up to now, the residual magnetic induction strength of the new generation of NdFeB permanent magnets has reached 147 T at room temperature. The maximum intrinsic coercivity sclera can exceed 1 000 kA/m, the maximum magnetic energy product (BH) can reach 398 kj/m, which is 5-12 times of ferrite permanent magnets and 3-10 times of Al-Ni-Co permanent magnets. The disadvantage of Nd-Fe-B permanent magnet material is that Curie temperature is low, the magnetic loss is large, thermal stability, corrosion resistance and oxidation resistance are poor when it is used at high temperature. Therefore, the surface of Nd-Fe-B permanent magnet should be coated according to its working environment to meet the requirements of the vehicle environment.

The magnetic and mechanical properties of Nd-Fe-B rare earth permanent magnets are obviously higher than those of ferrites and Al-Ni-Co permanent magnets.

The Performance of Permanent Magnet Synchronous Drive Motor

Permanent magnet synchronous drive motor (PMSM) can be divided into the surface type and built-in type by installing permanent magnet steel on the rotor. Surface type can be divided into the surface-mounted type and embedded type. According to the excitation direction of permanent magnet steel, the built-in type can be divided into radial type rotor structure, tangential type rotor structure and permanent magnet rotor structure with hybrid magnetic circuit integrating radial and tangential direction.

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Samarium Cobalt Magnets in Refrigeration Industry

In recent years, SmCo magnets have developed rapidly in the refrigeration industry. The development of magnet refrigeration depends not only on the development of magnets but also on the optimization of the external magnetic field circuit. For rotary room temperature refrigerators, based on Halbach array rotation theory, the magnetic induction intensity in the center of the working air gap increases with the height of the soft magnet, and there exists an extreme point, while the mass of the permanent magnet decreases gradually with the height of the soft magnet.

Maybe one day, your refrigerator can use magnets as refrigerants. Massachusetts Institute of Technology (MIT) scientists have recently developed an equation for describing electron transport in thermoelectricity to describe the transmission of magnets. They have found that if they are in a different magnetic field, the magnets may move from one end of the magnet to the other, taking away heat and producing a cooling effect. Relevant papers were published in the latest Physical Review Letters.

In ferromagnets, local magnetic moments can be rotated and arranged in different directions. At absolute zero, the arrangement of magnetic moments makes the magnet produce the strongest magnetic force; as the temperature rises, more magnetic moments spin becomes more asynchronous and the magnetic force weakens. The magnetic oscillator is produced with the increase in temperature. Magneto-oscillator is a quasi-particle in the magnet, which is formed by the joint rotation of magnetic moments. It is also called “spinor”.

Magnets Refrigeration

Magneto is very much like electrons. Electrons can carry charges and conduct heat at the same time. They can move under the action of the electric field or temperature difference. This phenomenon is called the thermoelectric effect.

Scientists have been studying thermoelectric effects, such as thermoelectric generators that convert heat directly into electricity or refrigerate without any moving parts. Magneto-oscillator can also move under two kinds of forces: temperature difference and magnetic field. Researchers have developed the Boltzmann equation describing electron transmission in thermoelectricity. After derivation, two new equations describing magneto transmission are obtained. They can use a new equation to predict the refrigeration effect of the magneto, similar to the thermoelectric refrigeration effect. When the magnetic oscillator is in a different magnetic field, it will carry heat from one end of the magnet to the other.

They built a model with ordinary magneto-insulators, collected data from previous data and entered the new model. It was found that when there is a mild magnetic field gradient, it can produce a smaller refrigeration effect, while at low temperature, the refrigeration effect is more obvious.

“You can absorb heat from one side to the other and essentially use magnets as refrigerators.” MIT mechanical engineering graduate student said, “You can imagine wireless refrigeration that can cool a magnet placed a meter or two away, or your portable computer by applying a magnetic field.” According to their theory, the magnetically refrigerated refrigerator does not need any moving parts, unlike traditional refrigerators, which use a tube to pump liquid continuously to maintain the low temperature.

The director of the MIT Department of Mechanical Engineering believes that the first applications of the magneto refrigeration effect may be those that require wireless refrigeration at very low temperatures. “At present, the possible applications are in the field of low temperatures, such as refrigerating infrared detectors. But we still need to prove this theory through experiments and find better materials. We hope this will promote new experiments.

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What is the Use of Magnets in Shock Absorbers

What is magnet shock absorber?

It is a kind of shock absorber, especially a magnet shock absorber based on the principle of the same pole repulsion of magnets. The utility model is characterized in that it contains an inner core, an outer gallbladder, a magnet and a fixing plate, and a pair of magnets are installed on the front, rear, left, right and bottom five surfaces of the inner core and the outer gallbladder, forming five pairs of magnets, making them opposite to each other at the same pole, thus generating a certain repulsive force. The magnet on the bottom of the outer gallbladder can also be replaced by an adjustable flux magnet device, which includes a circular magnet, a square magnet, a worm wheel, or a direct current magnet, or a gravity sensor installed on the inner core, which can realize real-time online vibration control through computer control.

What are the core components of magnet shock absorber?

The core components of the system are the linear motor and electronic controller ECU. In fact, the linear motor is a linear motor composed of the stator coil and moving magnet. Its working principle is the same as that of an ordinary rotary motor. The common rotary motor uses the change of current to make the stator coil of the motor produce a rotating magnetic field and induce the rotor magnet to rotate. The linear motor can be seen as a general rotary motor from the center of the circle along the radius cut, the flat expansion so that the original rotating magnetic field will become a magnetic field moving in a straight line direction, and the rotation of the rotor will become a straight line movement.

magnet shock absorber

What is the use of magnets in shock absorbers?

The high-density permanent magnet group is embedded in the moving piston, and the piston rod is fixed on the shock absorber cylinder body through nylon sliding bearings at both ends. There is an appropriate gap between the cylinder body and the piston so that the samarium cobalt magnet piston can slide freely in the cylinder body. The stator coil on the cylinder body is connected with the external electronic controller ECU through connecting wires.

When the electric vehicle is running on the road with good vibration absorption performance, because the lower end of the shock absorber is directly connected with the wheel or rocker, it drives the permanent magnet piston in the shock absorber to move up and down. The strong magnetic field formed by the high-density permanent magnet continuously cuts the stator coil, so that the stator coil generates inductive alternating current, which is converted into direct current after rectification, and conveys the electronic control switch.

The electronic switch directly controlled by ECU collects the induced electromotive force (average 25 W per trunk) generated on each electromagnetic shock absorber and the induced electromotive force (such as regenerative braking current) generated on other electronic devices, and transfers it to the battery for charging, so as to increase the battery power of the electric vehicle.

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The Role of Samarium Cobalt Magnet in Treatment

After the magnetization of the samarium-cobalt magnet, the water molecular bond of common water will be deformed at the same time. The hydrogen bond angle decreases from 105 degrees to 103 degrees, which changes the physical and chemical properties of water. The activity and solubility of water will also be improved correspondingly. CaCO3 in water will be decomposed into lower soft carbon during cooking. Calcium bisulfate is not easy to accumulate on the wall, on the contrary, it is easy to be carried away by water. Moreover, the degree of polymerization of water will be increased, and the dissolved solid material will become finer particles. When the particles are refined, the distance between the two ions is relatively small, so it is not easy to condense on the wall, so as to achieve the effect of scale removal.

samarium cobalt in treatment

Because of the different geographical environment and mineral content in water, harmful substances in water greatly affect our life and health.

Calcium and magnesium salts in water are insoluble, which affect the absorption and Photosynthesis of animals and plants. The practice and scientific experiments have proved that samarium-cobalt magnetization in “Wokai” can change the physical properties of water, such as surface tension, density, and solubility. Rare earth magnets have a significant impact on the chemical properties of acid and alkali. Magnetized water can increase the activity of enzymes in water and the permeability of biofilm. Regular drinking not only strengthens the healthy function of the body but also regulates the microcirculation system of the human body. Integrate, digest, endocrine and neurological functions, improve human immunity, prevent and treat a variety of diseases. After high-intensity magnetization, water molecules are activated and oxygen content is high.

Samarium cobalt magnets can be used for the following diseases:

1. Neurological diseases: insomnia, neurasthenia, headache, etc.

2. Osteoarticular muscular system diseases: cervical spondylosis, hyperosteogeny, periarthritis of shoulder, lumbar muscle strain, herniation of intervertebral disc, etc.

3. Others: hypertension, insufficient cerebral blood supply, slow cerebral blood flow, cerebral infarction, bronchitis, asthma, hemorrhoids, constipation, and other systemic diseases, as well as the pain and numbness caused by these diseases.

Neodymium Magnet VS Ferrite Magnet in Loudspeaker

Speakers are one of the electroacoustic materials. The basic material for making loudspeakers is a permanent magnet. Rare earth permanent magnet neodymium alloy is a very good material for making loudspeakers.

The working principle of loudspeaker
The permanent magnet generates a magnetic field in the annular air gap of the magnetic circuit through the yoke iron, and the voice coil connected with the speaker paper basin is inserted into the annular air gap. The permanent magnet is surrounded by the external yoke iron, thus avoiding the interference of the external stray magnetic field. In turn, it can reduce the influence of the magnetic field of the permanent magnet on the outside world. When the sound passes through the magnetic field in the form of current, the coil is formed. It will produce different frequencies of vibration due to the change of current intensity, and then drive the paper basin to emit different frequencies and strong sounds. The use of rare earth permanent magnet NdFeB instead of traditional ferrite or AlNiCo magnets can not only improve the sensitivity of loudspeakers but also greatly reduce the number of magnets used.

Magnet in Loudspeaker

The loudspeaker’s two favorite magnet materials are neodymium magnet and ferrite. Both are very strong, but they come with their own unique features.

NdFeB has the advantages of high-cost performance and good mechanical properties, while its disadvantages are low Curie temperature, poor temperature characteristics and easy to be powdered and corroded.

The manufacturers of bass headphone loudspeakers must adjust their chemical composition and adopt surface treatment methods to improve them. Only in this way, can the manufacturers of medium and high-pitch headphone loudspeakers meet the requirements of the practical application.

NdFeB belongs to the third generation of rare earth permanent magnets. It has the characteristics of small size, lightweight, and strong magnetism. It is a magnet with good performance-price ratio and is known as the king of magnets in the field of magnetics.

The advantages of high energy density make NdFeB permanent magnets widely used in modern industry and electronic technology. In the bare magnetic state, the magnetic force can reach about 3500 Gauss.

Magnet Loudspeaker

Ferrite is a kind of metal oxide with ferromagnetism. As far as electrical properties are concerned, the resistivity of ferrite is much larger than that of metal and alloy magnetic materials, and it also has higher dielectric properties. The magnetic properties of ferrite also show higher permeability at high frequencies.

Therefore, ferrite has become a non-metallic magnetic material widely used in the field of high frequency and weak current.

Ferrite is a kind of non-metallic magnetic material. It is a composite oxide of magnetic ferric oxide and one or more other metal oxides. The magnetic force is usually 800-1000 Gauss. It is often used in loudspeakers and other instruments.

What are the Applications of Aluminum Nickel Cobalt Magnet

Aluminum Nickel Cobalt (AlNiCo) is an iron alloy included aluminum (Al 8-12%), nickel (Ni 15-26%), cobalt (Co 5-24%) and small amounts of other metals elements that can enhance magnetic force (Cu 6%; Ti 1%; the rest Fe).
AlNiCo magnet is the first permanent magnet and its successful development promotes the wide application of the magnet. Although it is gradually replaced with the appearance of rare earth permanent magnets: SmCo magnet and neodymium magnet, AlNiCo magnet with its unique properties play an important role in many fields.

Aluminum Nickel Cobalt Magnet

Features of AlNiCo Magnets
Compared with SmCo magnets, AlNiCo has a higher working temperature, lower coercivity, lower BH(max) and cheap cost.
AlNiCo alloy material is very hard and brittle which can’t be made by cold work. Don’t worry; cast or sintered technology can solve this problem perfectly.
Permanent alnico magnets have high Curie temperature and extremely low reversible temperature coefficient -0.02%/℃allowing for excellent stability over a wide temperature range.
Alnico is also highly corrosion resistant. No coating required in all our last orders with the customer. Only some alnico magnets as teaching tool need paint red or blue color to identity south or North Pole.

Applications of AlNiCo Magnets
These fields include electric motors, guitar pickups, microphones, sensors, Halbach array, and engineering applications, traveling wave tubes, cow magnet, meters, bearings, aerospace applications, education, holding, heat treatment jigs and recovery and so on.

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