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Permanent Magnet Eddy Current Brake (PM-ECB)

What is Permanent Magnet Eddy Current Brake (PM-ECB)?

Permanent magnet eddy current brake is a kind of new brake assist system which researched and developed by the Japanese in the beginning of 20 century 90s. It was first applied to the braking device of railway vehicles. Compared with traditional friction braking, PM-ECB successfully gets rid of the impact of environmental change on the braking performance, making the operation and maintenance is very simple. In the background of more and more serious problems for today's energy and environmental, along with deep research of rare earth permanent magnet material, permanent magnet eddy current brake which has significant advantages becomes main stream of application research.

Permanent magnet eddy current brake has two forms:

1. Liner Permanent Magnet Eddy Current Braking, referred LPM-ECB

Arranging a series of permanent magnets with N and S poles alternately on both sides of the brake segment of a running track (or a track), while mounting the conductor plate in the right place of between permanent magnet and braked object, when the braked objects through this section, the magnetic flux generated by the permanent magnet will establish the travelling magnetic field in the air gap, making the conductor plate induced electromotive force and vortex, by the magnetic field interactions of the eddy current and permanent magnet, resulting tangential braking torque.
There are three kinds of magnetization directions for LPM-ECB: Halbach magnetized, horizontal magnetized and vertical magnetized.

2.Rotating Permanent Magnet Eddy Current Braking, called RPM-ECB

Rotating conductors produce eddy current while cutting magnetic field lines in the magnetic field generated by the permanent magnet; the eddy current generates Lorentz force in the magnetic field and the direction of the Lorentz force is opposite to the direction of conductor motion.

From the energy point of view, the above two kinds of permanent magnet eddy current brake mode, its essence is the use of Faraday's principle to convert the kinetic energy of moving objects into electrical energy, which is eventually dissipated from heat, so that the movement of an object or system slowdown.

What type of permanent magnet is used on eddy current?

In the permanent magnet eddy current brake, the permanent magnet is a vital component, which can directly affect the eddy current effect. So it should use high energy product, high coercivity NdFeB rare earth permanent magnet.

With the development of science, permanent magnet is developed from ferrite in early 20 century to the present NdFeB, NdFeB magnets with high coercivity and high magnetic energy products is more widely used.

Depending on different work environment, NdFeB permanent magnet is divided into N, H, SH, UH, EH and AH six series; from N to AH, permanent magnets decrease in the maximum energy product. In order to increase maximize performance of eddy current brake, it needs to select N series NdFeB permanent magnets.

Meanwhile, N serie NdFeB contains 35, 38, 40, 42, 45, 48, 50 and 52. Considering energy product and price, N45 and N48 are two grades most frequently chose by our customers. Some grade parameters of sintered NdFeB rare earth permanent magnet are listed as below:

The advantage for permanent magnet eddy current brake:
1. Simple structure, light weight.
2. Braking force with the stability and durability.
3. Good braking force under high speed.
4. No friction, low maintenance cost, long life, high reliability
5. Energy saving and environment protection
6. Smooth and soft braking process, simple and comfortable operation, reducing fatigue work of operator.

The applications for Permanent magnet eddy current brake:
1. passenger cars
2. trucks
3. high-speed trains
4. maglev trains
5. deep drilling rig
6. recreational facilities

China Magnets Source Material Ltd. is professional manufacturer of eddy current brake magnet, if you have magnet requirement, please feel free to contact us.

Contact information
China Magnets Source Material Limited
Tower B, Qiongzhu Building,
Huawang Rd,Longhua District,
Tel: +86 755 28174720
Fax: +86 755 28174720