CN201118426Y - Permanent magnet eddy current drive - Google Patents

Abstract

The permanent magnet eddy current transmission device is composed of an active rotating body, a passive rotating body and a permanent magnet part. It is characterized in that the active rotating body (1) of the permanent magnetic eddy current driving The copper plate (3) of the groove is formed by the back yoke (4), and the copper plate groove is filled with high magnetic permeability material. The active rotor is fixed on the input shaft (5), the air gap distance between the permanent magnet (2) and the copper plate (3) can be changed by the input shaft (5) through the air gap adjuster (7), and the passive rotor is fixed on the output shaft (6) The motor adopts a slotted structure of copper plate to improve the output power. By adjusting the air gap regulator on the output shaft, the size of the air gap magnetic field can be easily adjusted, thereby adjusting the motor speed, output power and output torque.

Description

Permanent magnet eddy current drive

technical field

The utility model relates to a permanent magnet eddy current transmission device, which belongs to the technical field of electric motor manufacturing.

Background technique

The application of permanent magnet transmission technology has a history of several decades. One of its applications is to transmit the power of the prime mover to the inner magnetic part on the working shaft through the outer magnetic part on its shaft. The inner and outer magnetic parts are separated by the isolation cover , so that the working shaft does not need to protrude out of the space to be sealed, and the dynamic seal is canceled to achieve safety, no seal, and zero leakage. Mainly used in pumps and compressors, mixers and valves in chemical industry, petrochemical industry, medicine and food industry. At present, the traditional mechanical seals used in a large number of fluid machinery in our country have been gradually replaced by permanent magnet transmission in these departments abroad.

Another application of permanent magnet transmission technology is the permanent magnet eddy current transmission device. The permanent magnet eddy current transmission device uses hysteresis material, which is a major feature of the device. The difference between the hysteresis material and the permanent magnet material is that the former is easy to change the polarity, so it is easy to adjust the torque and provides excellent operation performance, and it is widely used at present. But its rated torque is small, because at the rated torque, the clutch starts to slip, and the hysteresis material absorbs energy from the system. Due to the change of the magnetic pole, the kinetic energy becomes heat, and this part of heat should be dissipated and cooled in time. The adjustment and control of the torque of the permanent magnet eddy current drive is provided by the excitation coil, which requires a DC power supply and a control system. It is the best choice in automatic control system. The integration of magnetic devices with sensors and microprocessors can automate certain processes. For example, when the winding diameter of the winding machine is continuously increasing, by controlling the excitation current to change, the torque will also change accordingly to ensure a constant tension. This pair of printing machines-gravure printing machines, textile machines-cloth inspection machines, paper processing machines-paper cutting machines, metal processing machines-coating machines, wire cutting machines, steel bar heat treatment machines, coil machines, packaging machines Class - bag making machines, etc. are very valuable. Therefore, it is an excellent choice for process control of stretching and crimping of almost any material.

The permanent magnet eddy current transmission device technology discussed in this project is to realize the torque transmission between the motor and the load through the air gap through the simple mechanical structure (the interaction between the high-strength permanent magnet and the copper disc); the interaction between the motor and the load Keep running independently, without mechanical linkage. It is mainly composed of two parts, one part is composed of a high-strength permanent magnet (NdFeB) rotor connected to the drive side; the other part is a copper rotor composed of a copper disc connected to the load side.

The working principle of the permanent magnet transmission technology discussed in this project is: the copper rotor and the permanent magnet rotor can rotate freely and independently. Eddy currents are generated on the rotor, and at the same time, the eddy currents generate an induced magnetic field that interacts with the permanent magnetic field, thereby driving the copper rotor to rotate in the same direction as the permanent magnet rotor. As a result, torque is generated on the output shaft on the load side, thereby driving the load to rotate. When the air gap between the copper rotor and the magnetic steel rotor is fixed, different speed and torque transmission, soft start/stop of the motor, and overload protection of the motor are realized; when the air gap between the copper rotor and the magnetic steel rotor passes through If the servo mechanism is changed, the transmitted torque can be controlled to obtain an adjustable, controllable, and constant load speed, thereby realizing load speed regulation.

Contents of the invention

Technical problem: The technical problem to be solved by this utility model is to provide a permanent magnet eddy current transmission device with large output power and torque, which can adjust the output power and torque in real time.

Technical solution: In order to improve the output power and torque of the motor, the utility model adopts a special motor structure, that is, slots are made on the copper disk of the passive rotor, and the slots are filled with high magnetic permeability materials; moment, the present invention introduces the air gap adjuster section.

The copper disk is slotted and filled with high magnetic permeability material so that the air gap flux passes through the high magnetic permeability material and enters the passive rotor back yoke, thereby generating eddy current in the copper disk. Make full use of the electrical conductivity of copper and the magnetic permeability of high magnetic permeability material, so that the output power can be improved.

The utility model is specifically composed of an active rotating body, a passive rotating body and a permanent magnet. The active rotating body of the permanent magnet eddy current transmission device has two symmetrical pieces and is fixed on the input rotating shaft. The two active rotating bodies on the input rotating shaft There is an air gap adjuster between the bodies, and permanent magnets are pasted on the outer surface of the active rotating body; the passive rotating body includes a slotted copper plate and a back yoke, the back yoke is located on the outside of the device, and the copper plate slot is made of high magnetic permeability Material filling; the slotted copper disc is located on the outside of the active rotor, the input shaft can change the air gap distance between the permanent magnet and the copper disc by adjusting the air gap regulator, and the passive rotor is fixed on the output shaft.

In the slotted copper disc, the slots are evenly distributed on the circumference of the copper disc, the slots face the active rotating body, and the slots of the copper disc are filled with No. 35 steel with high magnetic permeability.

Beneficial effects: Since the copper plate of the passive rotor is slotted and filled with high magnetic permeability material, it can obtain higher output power and torque than ordinary permanent magnet eddy current braking devices, thereby increasing power density. In addition, since the air gap regulator is used in the input shaft of the clutch, the distance from the permanent magnet to the copper plate can be adjusted to change the air gap magnetic field, thereby adjusting the output power and torque.

Description of drawings

Fig. 1 is a schematic sectional view of a permanent magnet eddy current drive;

Fig. 2 is the slotting and eddy current schematic diagram of the copper plate of the permanent magnet eddy current transmission device of the present invention;

The above figure has: active rotor 1, permanent magnet 2, copper disk 3, copper disk groove 31, back yoke 4, input shaft 5, air gap adjuster 6, output shaft 7.

Detailed ways

The utility model adopts a special permanent magnet eddy current transmission device structure, that is, grooves are slotted in the copper disk of the passive rotor and filled with high magnetic permeability materials. The active rotating body 1 of this permanent magnet eddy current transmission has two symmetrical pieces and is fixed on the input shaft 5, and an air gap adjuster 7 is arranged between the two active rotating bodies 1 on the input rotating shaft 5, and the active rotating body The outer surface of 1 is pasted with permanent magnet 2; the passive rotating body includes a slotted copper disk 3 and a back yoke 4, the back yoke 4 is located on the outside of the device, and the copper disk groove 31 is filled with high magnetic permeability material; the slotted copper disk The disk 3 is located outside the active rotating body 1, the input rotating shaft 5 can change the air gap distance between the permanent magnet 2 and the copper disk 3 by adjusting the air gap adjuster 7, and the passive rotating body is fixed on the output rotating shaft 6. For the slotted copper disc 3, the grooves are evenly distributed on the circumference of the copper disc, and the notch faces the active rotating body. The copper disc groove 31 is filled with No. 35 steel with high magnetic permeability; the input shaft 5 can be adjusted by adjusting the air gap The device 7 changes the air gap distance between the permanent magnet 2 and the copper disk 3. The active rotating body, the back yoke of the passive rotating body and the filling materials in the copper plate groove are all made of high magnetic permeability materials, and the rotating shaft is made of non-magnetic conductive steel.

The magnetic flux path is: permanent magnet 2, passive rotor copper disc slot 3, passive rotor back yoke 4, adjacent copper disc slot 3, adjacent permanent magnet 2 with different polarity, active rotor 1, and finally returns to permanent magnet 2 .

Eddy current path: on the slotted copper disc 3, a circular current is formed on the peripheral copper disc around the notch.

In addition, in consideration of improving the air gap magnetic density of the motor and the thermal stability of the magnetic steel, the NdFeB permanent magnet material with high intrinsic coercive force is selected as the material for the permanent magnet 2 on the outer wall of the active rotor.

The copper disk is slotted and filled with high magnetic permeability material so that the air gap flux passes through the high magnetic permeability material and enters the passive rotor back yoke, thereby generating eddy current in the copper disk. Make full use of the electrical conductivity of copper and the magnetic permeability of high magnetic permeability material, so that the output power can be improved.

theoretical analysis

The finite element method is used to compare the loss, power and torque parameters of a prototype before and after slotting, and the governing equation to be solved is:

The eddy current in the passive rotating body is:

J＝σ(E+V×B)

The eddy current loss in the passive rotating body is:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}$

The eddy current loss in the passive rotating body is:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\underset{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}}{\overset{\mathrm{<span\; class="notranslate">\; no</span>}}{\mathrm{<span\; class="notranslate">\; \&Sigma;</span>}}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; \&Center\; Dot;</span>{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; v</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}$

Performance comparison: Table 1 lists the power and torque parameters of the transmission device before and after slotting. It can be seen that the output power and output torque of the transmission device can be improved after the copper plate is slotted.

Claims (2)

1. permanent magnetic vortex drive device, partly constitute by active rotation body, passive rotation body and permanent magnet, the active rotation body (1) that it is characterized in that this permanent magnetic vortex drive device has two of symmetry and is fixed in the input rotating shaft (5), be provided with air gap adjuster (7) between these the two active rotation bodies (1) in the input rotating shaft (5), the outer surface of active rotation body (1) posts permanent magnet (2); The passive rotation body comprises copper dish (3), the back of the body yoke (4) of fluting, and back of the body yoke (4) is positioned at the outside of this device, adopts high permeability material to fill in the copper dish groove (31); The copper dish (3) of fluting is positioned at the outside of active rotation body (1), and input rotating shaft (5) can be by regulating the air gap distance between air gap adjuster (7) change permanent magnet (2) and copper dish (3), and the passive rotation body is fixed on the output revolving shaft (6).

2. permanent magnetic vortex drive device according to claim 1 is characterized in that the copper dish (3) of described fluting, and groove evenly distributes on the circumference of copper dish, and notch is filled by No. 35 steel of high magnetic conduction in the copper dish groove (31) towards the active rotation body.

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