JPH0628945Y2 - Permanent magnet type motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention relates to a structure of an armature and a permanent magnet rotor of an electric motor using a permanent magnet.

2. Description of the Related Art In recent years, an increasing number of devices use a permanent magnet type electric motor even in devices that use only an induction motor. From the viewpoint of energy saving, it is desired to make the motor variable speed,
This is because a combination of a permanent magnet type electric motor and an inverter device has come to be used to form a variable speed system.

Since the permanent magnet type motor has a permanent magnet in its rotor, it must be magnetized. In magnetizing such an electric motor, a method is used in which the magnetizer is not used but the armature winding is used to perform the magnetization after the electric motor is assembled.

As one example thereof, Japanese Unexamined Patent Publication (Kokai) No. 57-142165 discloses a positioning method for re-magnetizing a demagnetized permanent magnet rotor, a magnetizing method for widening a magnetizing width of a magnet of the permanent magnet rotor, and an apparatus therefor. Is disclosed. FIG. 1 shows a partial cross-sectional view of a permanent magnet rotating machine and a cross-sectional view of a rotor. The permanent magnet uses a cylindrical magnet, and its magnetization is determined by a positioning power source and a stator winding. Current to the
After making the axis of the permanent magnet of the rotor coincide with the axis of the magnetomotive force of the stator winding, a current for re-magnetizing the permanent magnet of the rotor is supplied from the magnetizing power supply.

After assembling the armature and the permanent magnet rotor as described above,
Compared to the method of magnetizing the armature windings with a large current, the method of magnetizing the permanent magnet rotors as a unit is to magnetize after assembling. Since there is no action, there are advantages such as easy assembly work.

Further, as disclosed in JP-A-57-142165, the outer peripheral portion of the rotor permanent magnet of the motor having the output number + watt is designed to prevent the fragments of the permanent magnet from scattering due to centrifugal force during operation. Often covered with protective material.

Problems to be solved by the invention At present, in devices that require energy saving, it is required to improve the efficiency of electric motors. For this reason, isotropic permanent magnets are more often used for higher performance anisotropic permanent magnets. There is. However, it is difficult to obtain a cylindrical shape for an anisotropic permanent magnet, and as shown in JP-A-1-270756, a plurality of arc-shaped permanent magnets are actually used.

FIG. 4 shows a sectional view of a permanent magnet type electric motor using an arc-shaped permanent magnet. After fixing the arc-shaped permanent magnet 1 to the outer circumference of the iron core 2, both end surfaces of the rotor are protected by the end plates 3 and the outer circumference is protected by the pipe 4 in order to prevent the permanent magnet 1 from scattering due to centrifugal force during operation. Covered with wood.

On the other hand, the armature core 7 of the stator has a plurality of slots 8 and a plurality of teeth 9, and an armature winding 10 is wound around the slots 8.

However, at the time of magnetizing the rotor permanent magnet, the divided arc-shaped permanent magnet is fixed to the outer peripheral portion of the rotor iron core,
Since both end faces are covered with end plates and the outer circumference is covered with pipes, it is difficult to see the magnet division, and when magnetizing using the armature winding, it is caused by energizing the armature winding. Since the position of the magnetic pole and the predetermined position of the permanent magnet cannot be perfectly matched and ideal magnetization cannot be obtained, there is a problem that vibration and noise of the electric motor increase and the characteristics are impaired.

In view of the above problems, the present invention performs single-pole magnetization of only the N pole or the S pole on the outer peripheral surface of the rotor of each of the divided permanent magnets to make the magnetic flux distribution uniform and to prevent vibration during operation of the electric motor. An object of the present invention is to provide a permanent magnet type electric motor capable of reducing noise and increasing the total magnetic flux of permanent magnets.

Means for Solving the Problems In order to solve the conventional problems, the present invention provides a mark A indicating the positional relationship of magnetic poles generated by excitation of an armature winding at or near the tooth tips of an armature core, and A mark B indicating the positional relationship between the magnetic poles of the permanent magnet is provided near the outer diameter of the end plate of the permanent magnet rotor or the axial end of the protection pipe.

Operation According to the above configuration, the non-magnetized permanent magnet rotor is incorporated in the armature, and the mark A provided at or near the tooth tips of the armature core and the end plate of the permanent magnet rotor or the axial end of the protective pipe. A mark B corresponding to the magnetic pole position of the permanent magnet is aligned near the outer diameter of the portion in the circumferential direction visually or with a jig or the like to magnetize a predetermined permanent magnet at a predetermined position at a predetermined position of the permanent magnet rotor. Can be done. As a result, a high-performance permanent magnet type electric motor with less vibration can be obtained.

Embodiment Hereinafter, a permanent magnet type electric motor according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a plan view of an armature core of a permanent magnet type electric motor according to an embodiment of the present invention. 7 is an armature core, 8 is a slot for housing the armature winding, 9 is a plurality of teeth, 11 is a mark A
Indicates. The mark A11 is provided on at least one of the teeth 9 of the armature core 7 and at least at the end of the armature core 7 in the stacking direction. 2 is a cross-sectional view of a permanent magnet rotor of a permanent magnet type electric motor according to an embodiment of the present invention. Reference numeral 1 is an arc-shaped permanent magnet, 3 is an end plate, and 4 is a protective pipe. Reference numeral 12 indicates a mark B provided on the end plate 3, and at least one mark B is provided near the outer diameter of at least one axial end of the permanent magnet rotor 5.

FIG. 3 is a diagram showing the relative positions of the armature 6 and the permanent magnet rotor 5 when the permanent magnet 1 is magnetized using the armature and the permanent magnet rotor according to an embodiment of the present invention. By aligning the positions of the marks A11 provided on the teeth 9 of the armature core 7 and the marks B12 provided on the end plate 3 of the permanent magnet rotor in the circumferential direction,
Since the positional relationship between the magnetic pole 13 formed by the armature winding (not shown) and the magnetic pole of the permanent magnet rotor 5 can be defined,
A predetermined magnetic pole is magnetized at a predetermined circumferential position of the permanent magnet 1, and is provided at a position of the end plate 3 corresponding to the divided portion of the permanent magnet 1 and the mark A11 provided at the non-magnetic field position of the armature 6. By aligning the mark B12 with the circumferential method, the magnetization distribution of each magnet can be made uniform and the total amount of magnetic flux can be maximized. FIG. 5 compares the total amount of magnetic flux with the induced voltage when the motor is assembled. When the deviation of the magnetization angle exceeds 15 degrees, the induced voltage drops to about 96%.

FIGS. 6, 7, and 8 show the magnetic flux density distributions on the rotor surface measured while changing the magnetization angle. FIG. 6 shows the magnetic flux distribution of the present invention when the magnetization angle is not shifted.

FIG. 7 shows a state in which the magnetization angle is shifted by 15 degrees, and FIG. 8 shows 45 degrees.
Each of the magnetized waveforms is in a deviated state, and the magnetized waveform shows a divided portion of the permanent magnet 1. As is generally known, non-uniformity of the magnetized waveform causes vibration and noise.

As described above, according to the present invention, it is possible to obtain a motor having high characteristics with less vibration and noise. As a result, the electric motor has less vibration and noise and has high characteristics. The marks provided on the armature and the rotor may be of any shape as long as they can be easily discriminated from the outside.

Effect of the Invention According to the present invention, it is possible to magnetize a predetermined magnetic pole at a predetermined circumferential position of a permanent magnet, which reduces vibration and noise,
It is possible to provide a permanent magnet type electric motor having good characteristics.

[Brief description of drawings]

FIG. 1 is a plan view of an armature core of a permanent magnet type electric motor according to an embodiment of the present invention, and FIG. 2A is a partial sectional view showing a permanent magnet rotor of a permanent magnet type electric motor according to an embodiment of the present invention. , (B) is a sectional view in the coaxial direction, and FIG. 3 is a diagram showing relative positions of magnetic poles of an armature and a permanent magnet rotor when a permanent magnet of a permanent magnet type electric motor according to an embodiment of the present invention is magnetized. Fourth
FIG. 6 is a diagram showing an armature and a permanent magnet rotor of a conventional permanent magnet type motor, FIG. 5 is a characteristic diagram showing changes in induced voltage with respect to a deviation of the magnetization angle, and FIG. 6 is a diagram showing no deviation of the magnetization of the present invention. FIG. 7 is a diagram showing a magnetization waveform of the rotor permanent magnet in the case, FIG. 7 is a diagram showing a magnetization waveform when the magnetization angle is displaced by 15 degrees, and FIG. 8 is a diagram when the magnetization angle is displaced by 45 degrees. It is a figure which shows a magnetization waveform. 1 ... Permanent magnet, 3 ... End plate, 4 ... Protective pipe, 7 ...
Armature iron core, 8 ... Slot, 9 ... Tooth, 11 ... Mark A, 12 ... Mark B.

Claims (1)

[Scope of utility model registration request] 1. A permanent magnet having a plurality of arc-shaped cross sections, the permanent magnet being fixed to the outer circumference of an iron core, an end plate being provided at an end of the iron core, and the outer circumference of the permanent magnet being covered with a protective pipe. A permanent magnet rotor and an armature around which a winding is wound. After the armature and the permanent magnet rotor are aligned and assembled, the winding of the armature is energized to protect the protection. In a permanent magnet type electric motor that unipolarly magnetizes each of the plurality of arc-shaped permanent magnets through a pipe, a magnetic pole generated by excitation of an armature winding at or near a tooth tip of an armature iron core. An armature provided with a mark A indicating a positional relationship, and a permanent magnet rotor provided with a mark B indicating a positional relationship of magnetic poles of the permanent magnet near the outer diameter of the axial end of the end plate or the protection pipe. A permanent magnet type electric motor characterized by having.