JP2010045932A - Motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate controlling a permanent magnet synchronous motor at a low cost by lowering the required driving frequency of an inverter at a low cost. <P>SOLUTION: A motor includes one first pole 5 and one second pole 6. The first pole 5 and the second pole 6 each consist of a bar-like permanent magnet. The first pole 5 consists of a single bar-like or half-moon-like permanent magnet magnetized in S on the stator side and in N on the shaft side or of a plurality of continuously arranged bar-like or half-moon-like permanent magnets, each magnetized in S on the stator side and in N on the shaft side. The second pole 6 consists of all the permanent magnets, except for those constituting the first pole, each of which is a bar-like or half-moon-like permanent magnet magnetized in N on the stator side and in S on the shaft side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention includes a cylindrical rotor in which a shaft is inserted at the center and a plurality of permanent magnets arranged annularly with the shaft as a center, and a rotor arranged opposite to the circumferential surface of the rotor. In particular, the present invention relates to a motor having a shaft that rotates at a high speed relative to a general-purpose motor.

In recent years, so-called hybrid automobiles equipped with a motor together with an engine have been put into practical use as automobiles in consideration of the global environment.
As a motor mounted on such a hybrid vehicle, a permanent magnet synchronous motor in which a permanent magnet is accommodated in a rotor as shown in Patent Documents 1 to 11 is used.

On the other hand, a turbocharger rotates a turbine impeller using exhaust gas from an engine or the like and transmits the rotational drive to the impeller of the compressor to generate compressed air. Due to the fluctuation, torque shortage occurs, and compressed air may not be obtained stably. In view of this, a so-called electric supercharger has been proposed in which the above-described permanent magnet synchronous motor is used as a supercharger to compensate for the above torque shortage by the torque of the permanent magnet synchronous motor.
Japanese Patent No. 3811426 Japanese Patent No. 3819211 Japanese Patent No. 3596542 JP 2006-280195 A JP 2005-198487 A JP-A-2005-354798 JP 2005-328679 A JP 2003-324875 A Japanese Patent Laid-Open No. 2002-44888 JP 2000-350393 A JP 2001-258187 A

  However, the permanent magnet synchronous motor used for the electric supercharger is considerably different from the shaft in comparison with the permanent magnet synchronous motor mounted on the hybrid vehicle because the turbine impeller and the compressor impeller rotate at high speed. High-speed rotation is required.

  The electric supercharger is equipped with an inverter for converting the DC power of the battery into AC power of an arbitrary frequency so that the rotation of the rotor can be controlled. There is a possibility that the drive frequency of the inverter becomes very high. In other words, when the shaft is rotated at a high speed, it is necessary to convert the DC power into a high frequency AC power in order to control the rotation of the rotor. It is done.

  Moreover, since a permanent magnet synchronous motor will be mounted in a general purpose electric supercharger, cost reduction is especially desired.

  The present invention has been made in view of the above-described problems. In a permanent magnet synchronous motor, the required drive frequency of the inverter is reduced at low cost, thereby facilitating control at low cost. With the goal.

  The present invention adopts the following configuration as means for solving the above-described problems.

  According to a first aspect of the present invention, there is provided a cylindrical rotor having a shaft inserted through the center and containing a plurality of permanent magnets arranged in an annular shape with the shaft at the center, and a circumferential surface of the rotor. A motor including a stator that houses therein an armature winding for controlling the rotation of the rotor, the stator side being an S pole and the shaft side being an N pole, or a single array A first pole composed of a plurality of the rod-shaped or half-moon shaped permanent magnets, and the permanent magnet having the stator side as the N pole and the shaft side as the S pole. A configuration is adopted in which the second pole is constituted by the rod-shaped or half-moon shaped permanent magnet, which is all except the above-described permanent magnet.

  According to a second invention, in the first invention, a configuration is provided in which a flux barrier in contact with an end of the permanent magnet is provided.

  According to a third invention, in the first or second invention, at least one of the first pole and the second pole includes a plurality of the permanent magnets arranged in the extending direction of the shaft. ing

  A fourth invention adopts a configuration in which, in the third invention, the plurality of permanent magnets arranged in the extending direction of the shaft are arranged so as to be shifted from each other in the circumferential direction of the rotor.

  In a fifth aspect based on any one of the first to fourth aspects, at least one of the first pole and the second pole is disposed between the permanent magnet and the peripheral surface of the rotor. A configuration including an auxiliary permanent magnet is employed.

According to the present invention, the first pole constituted by a plurality of single or continuously arranged permanent magnets having the stator side as the S pole and the shaft side as the N pole, and the stator side as the N pole The shaft side is a permanent magnet having a south pole, and the second pole is constituted by all permanent magnets except the permanent magnet constituting the first pole.
That is, in the motor of the present invention, the magnets arranged in a ring form either the first pole or the second pole, and further include one each of the first pole and the second pole. It is a pole motor.
The drive frequency of the inverter increases in proportion to the number of poles of the motor. Therefore, by using the minimum number of poles as in the motor of the present invention, the drive frequency of the inverter can be reduced, for example, with respect to a motor having four or more poles.
Therefore, according to the present invention, in the permanent magnet synchronous motor, the control can be facilitated by reducing the required drive frequency of the inverter.

According to the present invention, the permanent magnet constituting the first pole and the second pole is a rod-shaped or half-moon shaped permanent magnet.
A rod-shaped or half-moon shaped permanent magnet has a simple shape and is a general-purpose product and can be manufactured at low cost.
Therefore, according to this invention, it becomes possible to manufacture at low cost.

  Therefore, according to the present invention, in the permanent magnet synchronous motor, it is possible to easily control at a low cost by reducing the required drive frequency of the inverter at a low cost.

  Hereinafter, an embodiment of a motor according to the present invention will be described with reference to the drawings. In the following drawings, the scale of each member is appropriately changed in order to make each member a recognizable size.

FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a motor 100 of the present embodiment. In FIG. 1, the motor 100 is cut along a plane perpendicular to the extending direction of the shaft.
The motor 100 of this embodiment is a motor capable of high-speed rotation that can be suitably used particularly for an electric supercharger.
As shown in FIG. 1, the motor 100 of this embodiment includes a shaft 1, a rotor 2, and a stator 3.

The shaft 1 is a rod member that transmits the rotational power generated by the rotor 2 and the stator 3 to the outside, and is arranged extending in the direction perpendicular to the paper surface of FIG.
In addition, since the motor 100 according to the present embodiment is capable of high-speed rotation as described above, the rigidity of the shaft 1 is the shaft included in the motors disclosed in the above-described Patent Documents 1 to 11 cited as the prior art documents. It is desired that the rigidity is higher than the rigidity. And in the motor 100 of this embodiment, the rigidity of the shaft 1 is improved by making the diameter of the shaft 1 larger than the shaft with which the motor disclosed by patent documents 1-11 is equipped.
In addition, when the rigidity of the shaft 1 can be improved by suitably selecting the forming material and shape of the shaft 1, the diameter of the shaft 1 is the same as the diameter of the shaft included in the motor disclosed in Patent Documents 1 to 11. Alternatively, it can be set small.
Moreover, it is preferable that the forming material of the shaft 1 is formed of a non-magnetic material so that the magnetic lines of force of a permanent magnet included in the rotor 2 described later are directed toward the stator 3 efficiently. However, the shaft 1 can also be formed of a magnetic material.

  The rotor 2 and the stator 3 generate a rotational force by a magnetic field line caused by a magnetic field and a current flowing through an armature winding described later, and the stator 3 is fixed and the rotor 2 is rotated.

  The rotor 2 has a cylindrical shape through which the shaft 1 is inserted at the center, and includes a rotor core 4, a first pole 5, a second pole 6, and a flux barrier 7.

The rotor core 4 forms the outer shape of the rotor 2, and is formed into a cylindrical shape in which a hole for inserting the shaft 1 is formed in the central portion and is formed of a magnetic material.
In the rotor core 4, two spaces for accommodating a permanent magnet constituting the first pole 5 and a permanent magnet constituting the second pole 6, which will be described later, are arranged annularly with the shaft as the center. The permanent magnet is accommodated in the space.
That is, in the motor 100 of this embodiment, the rotor 2 accommodates therein a plurality of permanent magnets that are inserted in the center and arranged in an annular shape with the shaft 1 as the center.
The rotor core 4 may be formed, for example, by laminating a plurality of circular electromagnetic steel plates in the extending direction of the shaft 1 or by ferrite in order to suppress the generation of eddy currents on the surface. preferable.

  As shown in FIG. 1, the first pole 5 and the second pole 6 are accommodated in the rotor core 4 arranged in a plurality of rings (six in this embodiment) with the shaft 1 at the center. The permanent magnet 10 is used. In addition, as the permanent magnet 10, a neodymium magnet can be used suitably, for example.

The motor 100 according to the present embodiment includes, as the permanent magnet 10, a rod-shaped first permanent magnet 11 in which the stator side is an S pole and the shaft side is an N pole, the stator side is an N pole, and the shaft side is an S pole. And a rod-shaped second permanent magnet 12. Three first permanent magnets 11 and two second permanent magnets 12 are continuously arranged with the shaft at the center.
The first pole 5 is constituted by three first permanent magnets 11, and the second pole 6 is constituted by three second permanent magnets 12. That is, the first pole 5 is constituted by a plurality of rod-shaped permanent magnets 10 (first permanent magnets 11) having the stator side as the S pole and the shaft side as the N pole. The second pole 6 is a rod-like permanent magnet 10 with the stator side being an N pole and the shaft side being an S pole, and all the permanent magnets 10 (except the permanent magnet 10 constituting the first pole 5). That is, it is constituted by the second permanent magnet 12).

That is, the motor 100 according to the present embodiment is a so-called two-pole motor that includes only the first pole 5 and the second pole 6 as poles.
In the motor 100 of the present embodiment, the first pole 5 and the second pole 6 are installed in a range of 160 ° without overlapping when viewed from the radial direction of the rotor 2. It has a length substantially equal to the length of the rotor 2 in the direction (extending direction of the shaft 1).

The flux barrier 7 is a high magnetic resistance region provided so as to be in contact with both end portions of the first permanent magnet 11 and both end portions of the second permanent magnet, and the flux barrier 7 in the first pole 5 and the second pole 6. The magnetic flux leakage from the stator side to the shaft side or from the shaft side to the stator side is suppressed.
And in the motor 100 of this embodiment, the flux barrier 7 is comprised by the void | hole. However, the flux barrier 7 is not limited to the holes, and can be configured by a member having a low magnetic permeability.

  The stator 3 is disposed to face the peripheral surface of the rotor 2 and accommodates an armature winding for controlling the rotation of the rotor. A plurality of armature windings are provided at equal pitches in the circumferential direction of the rotor 2. The number of armature windings is set in consideration of the width of the first pole 5 and the second pole 6 in the circumferential direction of the rotor 2 and the like.

  Although not shown in FIG. 1, the motor 100 of this embodiment may include a casing that covers and supports the stator 3.

  In the motor 100 of this embodiment having such a configuration, the rotor 2 is driven to rotate by supplying AC power from an external DC power source to the armature winding in the stator 3 via an inverter. Power is taken out through the shaft 1.

According to the motor 100 of the present embodiment as described above, the first pole 5 is constituted by a plurality of rod-shaped permanent magnets 10 (first permanent magnets 11) in which the stator side is the S pole and the shaft side is the N pole. All the permanent magnets 10 except for the permanent magnet 10 constituting the first pole 5, the second pole 6 is a rod-like permanent magnet 10 with the stator side being an N pole and the shaft side being an S pole. (Ie, the second permanent magnet 12). That is, the motor 100 according to the present embodiment is a so-called two-pole motor that includes only the first pole 5 and the second pole 6 as poles.
The drive frequency of the inverter that supplies AC power to the armature winding of the stator 3 increases in proportion to the number of poles of the motor. Therefore, by setting the minimum number of poles as in the motor 100 of the present embodiment, the drive frequency of the inverter can be reduced, for example, with respect to a motor having four or more poles.
Therefore, according to the motor 100 of the present embodiment, in the permanent magnet synchronous motor, it is possible to reduce the required drive frequency of the inverter and facilitate control.

Further, according to the motor 100 of the present embodiment, the permanent magnet 10 constituting the first pole 5 and the second pole 6 is a rod-shaped permanent magnet.
Since the rod-shaped permanent magnet has a simple shape and is a general-purpose product, the motor 100 of this embodiment can be manufactured at low cost.
Therefore, according to the motor 100 of this embodiment, it can be manufactured at low cost.

  Therefore, according to the motor 100 of the present embodiment, in the permanent magnet synchronous motor, it is possible to easily control at low cost by reducing the required inverter driving frequency at low cost. .

2 and 3, the permanent magnet 10 (the first permanent magnet 11 and the second permanent magnet 12) is divided into two or three minutes in the length direction of the rotor (the extending direction of the shaft 1). Also good. In other words, a plurality of small permanent magnets 10b having a shape in which the stator side and the shaft side are curved along the circumferential surface of the rotor 2 in the first pole 5 and the second pole 6 are arranged in the length direction of the rotor 2. You may make it comprise by.
When such a configuration is adopted, the size of each permanent magnet is reduced, the yield of the permanent magnet is improved, and even if it is damaged, only the damaged portion needs to be replaced. The motor 100 of this embodiment can be manufactured at a low price.
Note that only one of the first permanent magnet 11 and the second permanent magnet 12 of the permanent magnet 10 may be divided in the length direction of the rotor 2.

2 and 3, when the permanent magnet 10 is divided into a plurality of parts in the extending direction of the shaft 1, each permanent magnet 10 b is arranged around the rotor 2 as shown in FIGS. 4 and 5. Preferably, the rotor 2 is skewed by being displaced from each other in the direction.
Thus, by skewing the rotor 2, for example, vibration and noise of the motor 100 can be reduced.

Further, as shown in FIG. 6, the first pole 5 and the second pole 6 may be configured to include an auxiliary permanent magnet 20 disposed between the permanent magnet 10 and the peripheral surface of the rotor 2. good.
The auxiliary permanent magnet 20 disposed between the first permanent magnet 11 and the peripheral surface of the rotor 2 is a rod-shaped permanent magnet having an N pole on the shaft side and an S pole on the stator side, like the first permanent magnet 11. It is a magnet. Further, the auxiliary permanent magnet 20 disposed between the second permanent magnet 12 and the peripheral surface of the rotor 2 is a rod-shaped permanent magnet in which the shaft side is the S pole and the stator side is the N pole, like the second permanent magnet 12. It is a magnet.

  The magnetic force applied to the stator 2 by the first pole 5 or the second pole 6 affects both the magnetic flux from the permanent magnet 10 toward the stator and the magnetic flux from the auxiliary permanent magnet 20 toward the stator 2. Receive. For this reason, by arranging the auxiliary permanent magnet 20 between the permanent magnet 10 and the peripheral surface of the rotor 2, it is possible to cause the magnetic force to act on the stator 2 more efficiently.

  In addition, as shown in FIG. 7, instead of the rod-shaped permanent magnet 10, a half-moon shaped permanent magnet 30 is arranged, and the half-moon shaped permanent magnet 30 constitutes the first pole 5 and the second pole 6. You may do it.

Further, in the present embodiment, the example in which the first pole 5 and the second pole 6 are configured by three permanent magnets 10 has been described.
However, for example, as shown in FIG. 8, the first pole 5 and the second pole 6 may be constituted by two permanent magnets 10. Further, as shown in FIG. 9, the first pole 5 and the second pole 6 may be constituted by four permanent magnets 10. As shown in FIG. 10, the first pole 5 and the second pole 6 may be constituted by five permanent magnets 10. As shown in FIG. 11, the first pole 5 and the second pole 6 may be constituted by six permanent magnets 10.
In addition, since the number of the component parts of the motor 100 reduces because the number of the permanent magnets which comprise the 1st pole 5 and the 2nd pole 6 reduces, manufacture becomes easy.
Further, as the number of permanent magnets constituting the first pole 5 and the second pole 6 increases, the entire shape of the first pole 5 and the second pole 6 is curved along the circumferential surface of the rotor 2. Approach the shape. In the permanent magnet synchronous motor, an induced voltage generated in the armature winding of the stator when the rotor 2 is rotating may be measured, and the rotation of the rotor 2 may be controlled based on the measurement result. When the 5 and the second pole 6 approach a curved shape along the circumferential surface of the rotor 2, the measured induced voltage becomes a sine wave, and the rotation of the rotor 2 can be accurately controlled.

  The preferred embodiment of the motor according to the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to the above embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the configuration in which the permanent magnets 10 constituting the first pole 5 and the permanent magnets 10 constituting the second pole 5 are connected via the flux barrier 7 has been described.
However, the present invention is not limited to this, and a configuration in which the flux barrier 7 is not provided, or a configuration in which the permanent magnets 10 are not connected to each other may be employed.

Moreover, in the said embodiment, although the 1st pole 5 and the 2nd pole 6 are comprised symmetrically except the polarity of the permanent magnet 10, this invention is not limited to this, The first pole 5 and the second pole 6 do not have to be configured line-symmetrically.
For example, the first pole 5 may be constituted by two permanent magnets 10 and the second pole 6 may be constituted by three permanent magnets 10.

It is sectional drawing which showed schematic structure of the motor which is one Embodiment of this invention. It is sectional drawing which showed the motor by which the permanent magnet which is a modification of the motor which is one Embodiment of this invention was divided | segmented into two in the extension direction of the shaft. It is sectional drawing which showed the motor by which the permanent magnet which is a modification of the motor which is one Embodiment of this invention was divided | segmented into three in the extension direction of the shaft. FIG. 6 is a view showing a skew in a motor in which a permanent magnet which is a modified example of the motor according to the embodiment of the present invention is divided into two in a shaft extending direction. It is the figure which skewed in the motor by which the permanent magnet which is a modification of the motor which is one Embodiment of this invention was divided | segmented into three in the extension direction of the shaft. It is sectional drawing which showed the motor provided with the auxiliary | assistant permanent magnet which is a modification of the motor which is one Embodiment of this invention. It is sectional drawing which showed the motor provided with the half-moon shaped permanent magnet which is a modification of the motor which is one Embodiment of this invention. It is sectional drawing of the motor by which the 1st pole and 2nd pole which are the modifications of the motor which is one Embodiment of this invention were comprised by the permanent magnet of 2 each. It is sectional drawing of the motor by which the 1st pole and 2nd pole which are the modifications of the motor which is one Embodiment of this invention were comprised by the permanent magnet of 4 each. It is sectional drawing of the motor by which the 1st pole and 2nd pole which are the modifications of the motor which is one Embodiment of this invention were comprised by the permanent magnet of 5 each. It is sectional drawing of the motor by which the 1st pole and 2nd pole which are the modifications of the motor which is one Embodiment of this invention were comprised by the permanent magnet of six each.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 100 ... Motor, 1 ... Shaft, 2 ... Rotor, 3 ... Stator, 4 ... Rotor core, 5 ... First pole, 6 ... Second pole, 7 ... Flux barrier, 10, 30 ... Permanent magnet, 11 ... First permanent magnet, 12 ... Second permanent magnet, 20 ... Auxiliary permanent magnet

Claims (5)

A cylindrical rotor that houses a plurality of permanent magnets that are annularly arranged with the shaft at the center and a shaft inserted in the center, and is disposed opposite to the circumferential surface of the rotor and controls the rotation of the rotor A motor including a stator that houses an armature winding for
A first pole constituted by a plurality of the permanent magnets having a rod shape or a half moon shape arranged in a single or continuous manner, wherein the stator side is an S pole and the shaft side is an N pole;
The permanent magnet having the N pole on the stator side and the S pole on the shaft side is all of the permanent magnet except the permanent magnet constituting the first pole, and is constituted by the rod-shaped or half-moon shaped permanent magnet. And a second pole.   The motor according to claim 1, further comprising a flux barrier in contact with an end of the permanent magnet.   3. The motor according to claim 1, wherein at least one of the first pole and the second pole includes a plurality of the permanent magnets arranged in an extending direction of the shaft.   The motor according to claim 3, wherein the plurality of permanent magnets arranged in the extending direction of the shaft are arranged to be shifted from each other in the circumferential direction of the rotor. 5. At least one of the first pole and the second pole includes an auxiliary permanent magnet disposed between the permanent magnet and the peripheral surface of the rotor. The motor described.

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