JP2003235193A - Permanent magnet motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet motor in which magnetizing level of the resin mold insulation is raised for excellent insulation and improved performance. <P>SOLUTION: A concentrated-wound stator is provided where the magnetic pole teeth part of a motor stator is applied with resin mold insulation and a coil is directly wound around it. The height of the magnetic pole teeth end part of the stator on the slot opening side is 1.5 mm or lower. Related to the thickness of the resin mold insulation, the resin thickness of the magnetic pole teeth end part on the slot opening side is thicker than that of the magnetic pole teeth part, thus magnetization level and insulation are raised. The open angle θ of the tip pointed part which is formed by both magnetic pole teeth end parts of the magnetic pole teeth part is made 130° or smaller, with no abrupt flow of magnetic flux, resulting in improved performance of the permanent magnet motor. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent magnet type electric motor used in industrial equipment, office equipment, household appliances and having a permanent magnet in a rotor.

[0002]

2. Description of the Related Art In recent years, in permanent magnet type electric motors (hereinafter referred to as "electric motors") used for industrial, office, home electric appliances, and vehicles, a winding is directly wound around a magnetic pole tooth portion of a stator. Increasingly, the concentrated winding method is adopted. this is,
This is because the amount of copper in the winding can be reduced and the motor performance can be improved as compared to the conventional distributed winding method in which the stator is slot-to-slot. Also, the axial height of the stator of the electric motor can be reduced, and the case itself for fixing the electric motor can be reduced.

FIG. 10 shows a cross-sectional view of a conventional electric motor. Insulation 3 is applied to a slot 2 of a stator 1 of an electric motor, and a concentrated winding type winding 5 in which a winding is directly wound around a magnetic pole tooth portion 4 is applied. In FIG. 10, the number of slots of the stator 1 is 9 slots, and three-phase 6-poles are formed. Stator 1
Inside the rotor, there is a permanent magnet embedded rotor in which a permanent magnet 8 is embedded in a rotor core 7. Further, it is an adder type electric motor in which a shaft hole is provided on the inner diameter side of the permanent magnet embedded rotor and the shaft 10 is inserted.

Similarly, FIG. 11 also shows a cross-sectional view of another conventional electric motor. Insulation 31 is applied to the slot 21 of the stator 11 of the electric motor, and the concentrated winding type winding 51 in which the winding is directly wound is applied to the magnetic pole tooth portion 41. The number of slots of the stator 11 is nine, and three-phase six poles are formed as in FIG. Inside the stator 11, there is provided a permanent magnet-embedded rotor in which a permanent magnet 8 is embedded in a rotor core 7, and the shaft 10 is inserted into a shaft hole provided on the inner diameter side of the permanent magnet-embedded rotor. It is an inversion type electric motor. The difference between FIG. 10 and FIG. 11 lies in the shape of the magnetic pole tooth ends of the stator. In FIG. 10, both the root side 4a and the slot opening side 4b of the magnetic pole tooth end 9 are wide. In FIG. 11, the tip is tapered from the root side 4a of the magnetic pole tooth end 91 to the slot opening side 4b.

In the electric motors shown in FIGS. 10 and 11, there were the following problems. In FIG. 10, as described above, since both the root side 4a dimension and the slot opening side 4b dimension of the magnetic pole tooth end portion 9 are wide dimensions, the magnetic pole tooth portion 9 is wound around the magnetic pole tooth portion 4 of the stator 1 during operation. The magnetic flux generated in the magnetic pole tooth portion 4 due to the direction of the current flowing in the winding 5 easily flows also in the magnetic pole tooth end portion 9, and the magnetic flux of the rotor 6 facing the stator 1 is attracted and repulsed very much. growing. As a result, vibration and noise of the electric motor are generated.

Further, as described above, since it is the concentrated winding method in which the winding is directly wound around the magnetic pole tooth portion 4, the ratio of the magnetic flux concentrated on one magnetic pole tooth portion 4 varies from slot to slot of the conventional stator. This is much higher than that of the distributed winding method, and in particular, when the dimensions of the root side 4a of the magnetic pole tooth end 9 of the stator 1 and the dimension of the slot opening side 4b are both wide, the slot opening side of the magnetic pole tooth end 9 is Since the magnetic flux path extends to the end of 4b, the magnetic flux path area in the void portion of the magnetic pole tooth end portion 9 of the stator 1 facing the surface of the rotor 6 becomes large, and the inflow and outflow of the magnetic flux becomes very large. Therefore, it is easily affected by the reverse magnetic field and easily demagnetized. Also, the base side 4a of the magnetic pole tooth end portion 9
Since the dimension and the dimension of the slot opening side 4b are both wide, it was not possible to take a large slot cross-sectional area, so that it was not possible to wind many windings 5.

Therefore, as shown in FIG.
Each problem can be solved by tapering the tip from the root side 41a to the slot opening side 41b. That is, by making the tip taper from the root side 41a of the magnetic pole tooth end portion 91 to the slot opening side 41b, the magnetic flux generated in the magnetic pole tooth portion 41 during motor operation is
From the root side 41a of the magnetic pole tooth end 91 to the slot opening 41
Since the magnetic saturation gradually increases toward b, the magnetic flux flowing in the stator 11 gradually flows from the magnetic pole tooth portion 41 to the rotor 6 via the magnetic pole tooth end portion 91, which causes a sudden magnetic flux attraction and repulsion. Will not occur.

FIG. 12 shows the respective inverse magnetic field strengths in FIGS. 10 and 11. The horizontal axis represents the opening angle of the magnetic pole tooth end viewed from the inner diameter of the rotor 6. The vertical axis represents the strength of the reverse magnetic field applied to the magnetic pole tooth portion 41. As can be seen from FIG. 11, the reverse magnetic field strength applied to the tooth width of FIG.
It can be seen that the inverse magnetic field strength applied to the tooth width changes more gradually at both ends of the tooth width. As a result, there is no sudden change in the magnetic flux, and vibration and noise of the electric motor can be reduced.

Similarly, regarding the demagnetization proof strength of the rotor 6, the magnetic flux of the magnetic pole tooth portion 41 is the base side 41 of the magnetic pole tooth end portion 91.
By tapering the tip from a toward the slot opening side 41b, magnetic saturation occurs at the slot opening side 41b of the magnetic pole tooth end 91, and it becomes difficult for the magnetic flux to flow. As a result, the slot opening side 41b of the magnetic pole tooth end portion 91 is no longer a magnetic flux path, and thus the magnetic pole tooth portion 9 of the stator 11 facing the surface of the rotor 6 is formed.
The area for the substantial void portion of and is smaller than that in FIG. 10, and is less susceptible to the influence of the reverse magnetic field. Also, the stator 11
Since the tip is tapered from the root side 41a of the magnetic pole tooth end portion 91 toward the slot opening side 41b, a large slot cross-sectional area can be taken and more windings 51 can be wound than in FIG.

[0010]

As a result, although the problem of FIG. 10 can be solved by adopting the structure of FIG. 11,
A new problem arose in FIG.

When the rotor 6 is magnetized by using the winding 51 wound around the stator 11 for magnetizing the permanent magnet 8 embedded in the rotor 6 as a magnetizing winding, The strong magnetic field generated in the winding 51 by the large direct current flowing through the coil 51 tends to attract the rotor 6 made of a magnetic material located inside the stator. However, since the rotor 6 is fixed to the shaft 10, the winding 51 is attracted to the rotor 6 in reverse. As a result, as a matter of course, the tip end tapered portion on the slot opening side 41b of the magnetic pole tooth end portion 91 of the magnetic pole tooth portion 41 that supports the winding 51 so as not to project toward the inner diameter side of the stator 11 also has the rotor 6. It collapses to the side and transforms.
As a result, the tapered portion of the magnetic pole tooth end portion 91 on the inner diameter side of the stator 11 comes into contact with the rotor 6, deteriorating the performance of the electric motor and, depending on the situation, causing a burnout accident.

Further, as shown in FIG.
From the root side 41a of the magnetic pole tooth end 91 of the slot opening 4
The insulation 31 provided in the slot 21 of the stator 11 of the electric motor by tapering the tip toward 1b is arranged obliquely toward the slot opening side 41b along the magnetic pole tooth end 91, so that the stator 11 The winding 51 is easily projected to the inner diameter side of the. As a result, the winding 51 protruding to the inner diameter side of the stator 11 comes into contact with the rotor 6 to cause insulation failure and cause a burnout accident. As described above, since the amount of the winding wire 51 wound directly around the magnetic pole tooth portion 41 can be wound more in FIG. 11 than in FIG. 10, such a phenomenon becomes remarkable. Further, as a problem in both FIG. 10 and FIG. 11, there is a problem that the insulation distance between the magnetic pole tooth end portion of the stator and the winding cannot be maintained.

[0013]

According to a first aspect of the present invention, there is provided a concentrated winding type stator in which a magnetic pole tooth portion of a stator of an electric motor is provided with resin molding insulation and a direct winding is wound around the magnetic pole tooth portion of the stator. When the height of the end on the slot opening side is 1.5 mm or less, the resin thickness on the slot opening side of the magnetic pole tooth end is thicker than the resin thickness applied to the magnetic pole tooth on the thickness of the resin molding insulation. The electric motor

Alternatively, according to a second aspect of the present invention, in a concentrated winding type stator in which a magnetic pole tooth portion of a stator of an electric motor is resin-molded and insulated and a direct winding is wound, a slot at the magnetic pole tooth end portion of the stator is provided. When the height on the opening side is 1.5 mm or less, the point of the slot side corner portion on the slot opening side of one of the magnetic pole tooth ends of the magnetic pole tooth portion and the slot side corner portion on the root side of the magnetic pole tooth end portion. An extension line of the line connecting the points of, and a point of a slot side corner portion on the slot opening side of the other magnetic pole tooth end of the magnetic pole tooth portion,
The angle formed by the extension line of the line connecting the corners of the slot side on the root side of the magnetic pole tooth end is 130 ° or less when viewed from the inner diameter of the stator.

Further, in the invention of claim 3, when the resin thickness of the magnetic pole tooth portion of the resin molding insulation is A, A ≧ 0.5 m
3. The electric motor according to claim 1 or 2, wherein the resin thickness on the slot opening side of the magnetic pole tooth end is 3 A or more in m.

Further, in the invention of claim 4, when the resin thickness of the magnetic pole tooth portion of the resin molding insulation is A, A ≧ 0.5 m
In m, the resin thickness on the slot opening side of the magnetic pole tooth end is 3A or more, and the resin molding insulation is formed in an L shape from the root side of the magnetic pole tooth end to the slot opening side of the magnetic pole tooth end. The electric motor according to claim 1 or claim 2.

Further, the invention of claim 5 is the electric motor according to any one of claims 1 to 4, wherein the material of the resin molding insulation is super engineering plastic (super engineering plastic). The invention according to claim 6 is the electric motor according to any one of claims 1 to 5, wherein the resin molding insulation is integrally resin molded by mounting a stator core on a resin filled mold.

According to a seventh aspect of the present invention, in the permanent magnet type electric motor, the permanent magnet is embedded in the rotor, and the axial height of the permanent magnet is lower than the laminated thickness of the stator core. The electric motor according to claim 6.

The invention according to claim 8 is the motor according to claim 7, wherein the permanent magnet embedded in the rotor of the motor is a rare earth magnet.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Now, let us consider the shape of the magnetic pole tooth end portion 91 shown in the conventional example of FIG. In FIG. 1, the vertical axis represents the amount of deformation of the tapered portion on the slot opening side 41b when the rotor 6 in which the permanent magnet 8 is embedded is magnetized using the winding 51 of the stator 11 as a magnetizing winding. , The horizontal axis represents the height of the pole tooth end 91 on the slot opening side 41b.
It is expressed as. As can be seen from this, when the winding 51 of the stator 11 is a magnetized winding, the height of the tapered portion on the slot opening side 41b of the magnetic pole tooth end portion 91 is deformed at 1.5 mm or less. As a result, the tapered tip portion of the magnetic pole tooth end portion on the inner diameter side of the stator comes into contact with the rotor, which deteriorates the performance of the electric motor and may cause a burnout accident depending on the situation.

In view of this, the first embodiment of the present invention will be described with reference to the drawings. Incidentally, the reference numerals used in the prior art are used for the portions having no structural problems. In the partially enlarged view of FIG. 2, a resin molding insulation 32 is applied to the slot 22 of the stator 12 of the electric motor, and a concentrated winding type winding 52 in which a winding is directly wound around the magnetic pole tooth portion 42 is applied. Further, the magnetic pole tooth end portion 92 of the stator 12 is located at the base side 42 of the magnetic pole tooth end portion 92.
1.5 mm from a to T on the slot opening side 42b
It has the following tapered shape. Inside the stator 12, the rotor 6 is provided so as to face the magnetic pole teeth 42 protruding toward the inner diameter side. This rotor 6 has a rotor core 7
It is an inversion type electric motor having a permanent magnet embedded rotor having a permanent magnet 8 embedded therein and a shaft 10 inserted into the inner diameter of the permanent magnet embedded rotor.

Slot opening side 42b of the magnetic pole tooth end portion 92
The effect of the tapered tip shape at 1.5 mm or less over T is that the magnetic flux from the magnetic pole tooth portion 42 of the stator 12 gradually flows into the rotor 6 via the magnetic pole tooth end portion 92, and a sudden magnetic flux is generated. Suction and repulsion are eliminated, and vibration and noise of the electric motor can be reduced. Further, since magnetic saturation occurs in the tapered portion on the slot opening side 42b of the magnetic pole tooth end portion 92, and it becomes difficult for the magnetic flux to flow, the magnetic path on which the reverse magnetic field is applied is narrowed and the influence of demagnetization is less likely to occur.

Further, for a motor in which the height T of the magnetic pole tooth end portion 92 on the slot opening side 42b is 1.5 mm or less, the thickness of the resin molding insulation 32 is smaller than the resin thickness on both sides of the magnetic pole tooth portion 42. By increasing the resin thickness on the slot opening side 42b of the tooth end portion 92, it is possible to increase the strength of the resin molding insulation of the tapered tip end portion of the magnetic pole tooth end portion 92. As a result, even if the rotor 6 in which the permanent magnet 8 is embedded is magnetized by using the winding 52 of the stator 12 as a magnetizing winding, the magnetic pole tooth end portion 9 is formed.
It is possible to prevent the tooth bending of the second stator from the inner side of the stator, the contact failure between the magnetic pole tooth end portion 92 and the rotor 6 is eliminated, and the performance of the electric motor is not deteriorated. Further, from the root side 42a of the magnetic pole tooth end portion 92 of the stator to the slot opening side 42b.
Since the tip has a tapered shape of 1.5 mm or less toward T, many windings 52 can be wound.

Further, in the second embodiment, the stator 12 is
The height T of the magnetic pole tooth end portion 92 on the slot opening side 42b is 1.5 mm or less, and the point of the slot side corner portion of the one magnetic pole tooth end portion 92 of the magnetic pole tooth end 42 on the slot opening side 42b. bb, an extension line of a line connecting the point aa of the slot side corner of the root side 42a of the magnetic pole tooth end portion 92, and the magnetic pole tooth portion 4
2 is an extension of the line connecting the point bb ′ of the slot side corner of the other magnetic pole tooth end 92 on the slot opening side 42b and the point aa ′ of the slot side corner of the root side 42a of the magnetic pole tooth end 92. By setting the crossing angle θ formed by the line to be 130 ° or less when viewed from the inner diameter of the stator, it is possible to eliminate a sharp corner that obstructs the flow of magnetic flux.

2 and 3, the intersection angle θ and the points aa and a of the slot side corner portion of the root side 42a of the magnetic pole tooth end portion 92.
The magnetic flux density at a ′ will be described. In FIG. 3, the vertical axis represents the magnetic flux density at the points aa and aa ′ of the slot side corners on the root side 42a of the magnetic pole tooth end 92, and the horizontal axis represents the crossing angle θ. As can be seen from FIG. 3, the wider the crossing angle θ is, the more the magnetic flux concentrates on the points aa and aa ′ at the corners on the slot side of the root side 42a of the magnetic pole tooth end 92, and the magnetic saturation occurs.
As a result, the electric motor performance is deteriorated. vice versa,
The narrower the crossing angle θ is, the closer to the root side 4 the magnetic pole tooth end portion 4 is.
The flow of magnetic flux at the points aa and aa 'at the corners on the slot side of 2a becomes gentle, and the motor performance does not deteriorate.

As can be seen from the above, the crossing angle θ that can maximize the performance of the electromagnetic steel sheet is determined by the root side 42 of the magnetic pole tooth end portion 42.
By making the magnetic pole tooth end shape such that the magnetic flux densities at the corners aa and aa 'of the slot side of a are 130 ° or less immediately before magnetic saturation, the performance of the electromagnetic steel sheet can be maximized.

In order to improve the performance of the motor, the winding 5
2 must be wound around the magnetic pole tooth end portion 92 as much as possible, but if the crossing angle θ is too narrow, the winding 52 wound around the magnetic pole tooth portion 92 will easily jump out from the slot opening to the stator inner diameter, so that The angle θ is preferably a dimension that does not form a very acute angle. Preferably, by setting the angle to 110 ° or more, the amount of the winding 52 protruding from the slot opening to the inner diameter side of the stator 12 is reduced.

Therefore, the point b of the slot side corner of the one side pole tooth end 92 of the pole tooth portion 42 on the slot opening side 42b.
b, an extension line of a line connecting the point aa of the slot side corner portion on the root side 42a of the magnetic pole tooth end portion 92, and the slot on the slot opening side 42b of the other magnetic pole tooth end portion 92 of the magnetic pole tooth portion 42. Point bb ′ of the side corner and the root side 42a of the magnetic pole tooth end 92
The angle formed by the extension of the line connecting the points aa ′ of the slot side corners of the slot side angle of the root side 42a of the magnetic pole tooth end portion 92 is 130 ° or more when viewed from the inner diameter of the stator 12. Since it is possible to eliminate sharp corners that hinder the flow of the magnetic flux at the points aa and aa 'of the parts, the performance of the electric motor can be improved.

The crossing angle θ is determined by the point bb at the corner of the slot side of the magnetic pole tooth end portion 92 of the magnetic pole tooth end portion 92 on the side of the slot opening 42b, and the root side 42a of the magnetic pole tooth end portion 42 of the pole side. An extension of a line connecting the corner points aa and the slot opening side 42b of the other magnetic pole tooth end portion 92 of the magnetic pole tooth portion 42.
The angle between the slot side corner point bb ′ and the extension line of the line connecting the slot side corner point aa ′ on the root side 42a of the magnetic pole tooth end portion 92 may be made, and therefore, the magnetic pole tooth portion 42. The tips of the two magnetic pole tooth ends 92 do not have to have the same height.
This will be described with reference to a partially enlarged view of FIG.

As shown in the partially enlarged view of FIG.
When the height of one of the magnetic pole tooth ends 93 on the slot opening side 43b is a and the height of the other magnetic pole tooth end 93 on the slot opening side 43b is b, a ≧ b may be satisfied. . Further, it may be a ≦ b. In this case, if the height of the slot opening portion side 43b of one magnetic pole tooth end portion 93 is increased, the magnetic flux density is increased on the root side 43a of the magnetic pole tooth end portion 93, and the flow of magnetic flux is impeded. If the height of the magnetic pole tooth end portion 93 on the side of the slot opening portion 43b is lowered, the magnetic flux density on the root side 43a of the magnetic pole tooth end portion 93 becomes low, and the magnetic flux gently flows. Therefore, since the effect is obtained in the average of the total magnetic flux densities obtained at the both magnetic pole tooth ends 93 of the magnetic pole tooth portion 43, the same result as the above is obtained.

Next, a third embodiment will be described with reference to FIG. FIG. 5 is similar to FIGS. 2 and 4, and is a partially enlarged view of the magnetic pole tooth portion 44 in which the resin molding insulation 34 is applied to the magnetic pole tooth end portion 94 and the direct winding 54 is wound. In FIG. 5, the thickness of the resin molding insulation 34 located on both sides of the magnetic pole tooth portion 44 is A, and when A ≧ 0.5 mm, the magnetic pole tooth end portion 94 is formed.
The thickness of the resin molding insulation 34 on the slot opening side 44b is 3 A or more. As a result, the slot opening side 4
The insulation distance between the iron core portion of the magnetic pole tooth end portion 4b of 4b and the winding 54 wound directly around the magnetic pole tooth portion 44 can be secured, and the dielectric strength is improved.

Here, the thickness A of the resin molding insulation 34 located on both sides of the magnetic pole tooth portion 44 is preferably as thin as possible in order to wind as many windings 54 mounted in the slots 24 as possible. It is sufficient that the size of the insulation 34 is not less than the minimum manufacturable size that allows the molten metal in the resin-filled mold to be produced without any problem, and preferably 0.5 mm or more so that the resin-molded insulation 34 can be produced without problems. More windings 54 can be wound.

FIG. 6 shows the resin molding insulation on the slot opening side 44b of the magnetic pole tooth end portion 94 in the withstand voltage test when the thickness A of the resin molding insulation 34 on both sides of the magnetic pole tooth 44 is 0.5 mm. It is a test result of withstand voltage when the thickness of 34 is changed to A, 2A, 3A. JIS standard C421
According to 2. Here, assuming that the rated voltage E is a motor rated output of 1 kW or more, 2E + 1000 (V)
Must withstand (min 1500V) for 1 minute. In FIG. 6, the slot opening side 44 of the pole tooth end 94 is shown.
It can be seen that the dielectric strength can be maintained by setting the thickness of the resin molded insulation 34 of b to 3 A or more.

Further, as described above, when the permanent magnet 8 embedded in the rotor 6 is magnetized by using the winding 54 of the stator 14 as the magnetizing winding, the magnetic pole tooth end portion 94 has the slot opening. Since the tip 54 has a tapered tip shape of 1.5 mm or less toward the portion side 44b, the tapered tip portion is easily deformed by the force of the winding 54 falling toward the inner diameter side of the stator 14, but The thickness of the resin molding insulation 34 located on both sides is set to A, and when A ≧ 0.5, the thickness of the resin molding insulation 34 on the slot opening side 44b of the magnetic pole tooth end portion 94 is set to 3 A or more, so that The shape of the portion 94 is 4 on the slot opening side.
It is possible to maintain the strength against magnetization on the slot opening side 44b of the magnetic pole tooth end portion 94 even if the tip is tapered to 1.5 mm or less toward 4b.

Therefore, in order to obtain the synergistic effect of dielectric strength and magnetizing strength, the thickness of the resin molding insulation 34 is set to A and A ≧ 0.
At 5 mm, slot opening side 4 of magnetic pole tooth end 94
By setting the thickness of the resin molding insulation 34 of 4b to 3 A or more, a better effect can be obtained.

The fourth embodiment has the same effect as that of FIG. 5, and is particularly advantageous when applied to an electric motor having a large number of turns 55 as shown in FIG. The thickness of the resin molding insulation 35 on the slot opening side 45b of the magnetic pole tooth end 95 is set to 3
By setting A or more, the insulation distance is secured, the dielectric strength is improved, and more windings 55 can be wound. In addition, an L-shape is extended from the root side 45a of the magnetic pole tooth end 95 to the slot opening side 45b. By forming it into a shape, more windings 55 can be wound than in FIG.

When the electric motor of the present invention is used as an electric motor mounted in a hermetic compressor such as an air conditioner or a refrigerator, the refrigerant (HFC134a, HFC4) in the hermetic compressor is used.
10a, HFC407c, etc.) and the amount of water contained in the refrigerating machine oil (mixed oil such as polyalkylene glycol-based oil, polyester-based oil or ether-based oil) causes the resin molded insulators 32 to 35 to hydrolyze, resulting in insulation failure. You have to be careful not to be.

Therefore, in the fifth embodiment, the material of the resin molding insulations 32 to 35 is made of super engineering plastic (super.
By using an engineering plastic), it becomes possible to minimize the hydrolysis of the resin-molded insulators 32 to 35, which has been a problem in the past, due to the amount of water contained in the refrigerator oil. As a super engineering plastic,
For example, polyethylene naphthalate (PEN), polyethylene sulfide (PPS), liquid crystal polymer resin (L
CP), fluororesin, polyetheretherketone (P
EEK) etc.

Further, in the sixth embodiment, the stators 12 to 1
5. Resin molded insulation 32 to be attached to the magnetic pole tooth portions 42 to 45 of FIG.
By arranging the stator cores 35 to 35 in the resin-filled mold and integrally molding the resin, it is possible to save the work of mounting the resin-molded insulation, which has been conventionally divided, on the magnetic pole teeth of the stator. In addition, since the resin-molded insulation is integrally resin-molded, there is no joint between the resin-molded insulations as compared with the resin-molded insulation that is divided and arranged, so insulation failure between the stator and the winding at this joint is eliminated. Also disappears. As a result, a product with stable quality can be provided.

A seventh embodiment will be described with reference to FIGS. 8 and 9. FIG. 8 is a sectional view taken along line BB 'in FIG. FIG. 8 shows a concentrated winding type electric motor in which the magnetic pole tooth portion 41 of the stator 11 is provided with resin molding insulation 31 and the winding is directly wound. Further, a permanent magnet 8 is embedded on the inner diameter side of the stator 11 to arrange a permanent magnet type rotor, and the permanent magnet 8 projects at both axial ends of the magnet housing hole 100 in which the permanent magnet 8 is embedded. Don't let the end plates 110a and 11
Blocked by 0b. In FIG. 8, the axial length Lo of the permanent magnet 8 embedded in the permanent magnet rotor is longer than the laminated thickness L of the stator core.

In FIG. 8, the magnetic pole tooth portion 41 of the stator 11 is shown.
Concentrated winding type stator 1 in which winding 51 is directly wound around
When the permanent magnet type rotor arranged inside the stator 11 is magnetized by using the winding 51 of No. 1 as a magnetizing winding, as described above, due to the large direct current flowing through the winding 51 of the stator 11, The strong magnetic field generated in the winding 51 tends to attract the rotor 6 made of a magnetic material inside the stator 11. However,
Since the rotor 6 is fixed to the shaft 10, the stator 1
On the contrary, the one winding 51 is attracted to the rotor 6. As a result, the winding 51 is rotated by the rotor 6 with a force exceeding the strength of the resin-molded insulation 31 axially extending from the end surface of the stator 11.
Therefore, the root portion of the resin molding insulation 31 extending in the axial direction is easily damaged. As a result, insulation failure between the iron core of the stator 11 and the winding wire 51, or depending on the situation, the resin molding insulation 31 may fall off during operation of the motor, causing a burnout accident.

In FIG. 9, in order to solve this problem, the axial length L1 of the permanent magnet 81 embedded in the permanent magnet rotor is set to be smaller than the laminated thickness L of the iron core of the stator 11, and the end of the stator 11 is reduced. The rotor core 71, in which the permanent magnet 81 is embedded in the portion facing the winding 51 protruding in the axial direction from the portion, has the same height as the iron core of the stator 11 or less. As a result, the height of the permanent magnet 81 embedded in the rotor iron core 71 also becomes lower than the stack thickness height of the iron core of the stator 11. Therefore, since there is no rotor 61 in which the permanent magnet 81 is embedded at a position facing the winding 51 protruding axially from the end of the stator 11, the winding 51 is strongly attracted to the rotor 61. Resin insulation 3 which is the cause of poor insulation
It is possible to eliminate damage at the root portion of 1. Further, the resin-molded insulation 31 does not fall off during the operation of the electric motor. Further, the amount of the permanent magnet 81 used can be reduced and the material cost can be reduced.

In the case where the permanent magnet 81 embedded in the permanent magnet type rotor shown in the seventh embodiment is a rare earth magnet requiring a strong magnetizing magnetic field, the embodiment of FIG. 9 is preferable. The effect can be obtained.

[0044]

As is apparent from the embodiments of the present invention, in the concentrated winding type stator in which the magnetic pole teeth of the stator of the electric motor are directly wound with the resin molding insulation, the magnetic pole teeth ends of the stator are provided. When magnetizing a permanent magnet type rotor in which permanent magnets are embedded by using the stator winding as a magnetizing winding when the height of the part is 1.5 mm or less, the winding is made of a magnetic material. Because of being attracted, the tip of the magnetic pole tooth on the slot opening side is permanently deformed toward the inner diameter side of the stator.

In this case, the stator winding is magnetized by making the resin molding insulation thicker than the resin thickness on both sides of the magnetic pole tooth portion on the slot opening side of the magnetic pole tooth end. Even if the rotor with a permanent magnet embedded as a wire is magnetized, the strength of the resin molding insulation at the tip of the magnetic pole tooth end is increased, so the stator core of the tip of the magnetic pole tooth end is deformed. There is no possibility of contacting the rotor and degrading the performance of the electric motor. In addition, it does not cause a burnout accident.

Further, the thickness of the magnetic pole tooth portion of the resin molding insulation is A
By setting the resin thickness on the slot opening side of the magnetic pole tooth end portion to 3 A or more when A ≧ 0.5 mm, the magnetizing strength can be reliably increased. Also, the insulation distance between the winding and the magnetic pole tooth end can be maintained.

From the viewpoint of the performance of the electric motor, the shape of the magnetic pole tooth end is defined by the point of the slot side corner on one slot opening side of the magnetic pole tooth end and the root side slot side corner of the magnetic pole tooth end. The extension line of the line connecting the points of the part, the point of the slot side corner of the other slot opening side of the magnetic pole tooth end, and the point of the slot side corner of the root side of the magnetic pole tooth end are connected. By setting the angle formed by the extension line of the wire to be 130 ° or less when viewed from the inner diameter of the stator, it is possible to improve the performance of the electric motor by eliminating a sudden change in magnetic flux at the root-side corner of the magnetic pole tooth end.

Further, the shape of the slot opening portion at the magnetic pole tooth end portion of the resin molding insulation is L-shaped from the root side of the magnetic pole tooth end portion to the slot opening portion side of the magnetic pole tooth end portion, so that more shapes can be obtained. The winding can be wound, and the winding is less likely to protrude from the slot opening toward the inner diameter side of the stator.

Further, when the electric motor of the present invention is used as an electric motor mounted in a hermetic compressor of an air conditioner and a refrigerator, the water content in the refrigerating machine oil, which has been a problem in the related art, can be obtained by using resin molding insulation as super engineering plastic. It is possible to minimize hydrolysis due to.

Further, the resin-molded insulation is an electric motor in which a stator core is mounted on a resin-filled mold and is integrally resin-molded, so that the stator is wound with windings as compared with the case where divided resin-molded insulation is used. It is possible to save the labor of installing the resin molded insulation before winding, and to eliminate the insulation failure at the joint part of the resin molded insulation which is divided and to produce a product of stable quality. You can

Further, in the problem of the magnetic strength against the magnetization of the resin molding insulation, the axial height of the permanent magnet is made lower than the product thickness of the stator core, so that the permanent magnet protrudes from the end portion of the stator in the axial direction. Since the rotor, which is a magnetic material, does not exist in the portion facing the winding, the winding is not strongly attracted to the rotor, and damage to the resin-molded insulation that causes insulation failure can be eliminated. Further, it is possible to eliminate a burnout accident due to the resin molding insulation falling off while the motor is operating. This is a good effect when a rare earth magnet having a strong magnetic force is used as the permanent magnet.

[Brief description of drawings]

FIG. 1 shows a deformation amount due to magnetization at a height T of a magnetic pole tooth end portion on a slot opening side.

FIG. 2 is a partially enlarged view of magnetic pole tooth portions showing the first and second embodiments of the present invention.

FIG. 3 shows a magnetic flux density at a root portion of a magnetic pole tooth portion according to a second embodiment of the present invention.

FIG. 4 is a partially enlarged view of a magnetic pole tooth portion showing another embodiment of the second embodiment of the present invention.

FIG. 5 is a partially enlarged view of a magnetic pole tooth portion showing a third embodiment of the present invention.

FIG. 6 shows the dielectric strength due to resin molding insulation between the stator core portion on the slot opening side of the magnetic pole tooth portion and the winding in the third embodiment of the present invention.

FIG. 7 is a partially enlarged view of a magnetic pole tooth portion showing a fourth embodiment of the present invention.

8 is a vertical cross-sectional view of BB 'in the magnetic pole tooth portion of FIG.

FIG. 9 is a vertical sectional view of a magnetic pole tooth portion showing a seventh embodiment of the present invention.

FIG. 10 is a cross-sectional view of a permanent magnet type electric motor showing a conventional example.

FIG. 11 is a cross-sectional view of a permanent magnet type electric motor showing another conventional example.

FIG. 12 shows the inverse magnetic field strength in FIGS. 10 and 11 of the conventional example.

[Explanation of symbols]

1, 11, 12, 13, 14, 15, ... Stator, 2,
21, 22, 23, 24, 25 ... Slots, 3, 3
1 ... Insulation, 32, 33, 34, 35 ... Resin molding insulation, 4, 41, 42, 43, 44, 45 ... Magnetic pole tooth portions 4a, 41a, 42a, 43a, 44a, 45a.
..Root side of magnetic pole tooth ends, 4b, 41b, 42b, 4
3b, 44b, 45b ... Slot opening side of magnetic pole tooth end, 5, 51, 52, 53, 54, 55 ... Winding,
6,61 ... Rotor, 7,71 ... Rotor core,
8, 81 ... Permanent magnets, 9, 91, 92, 93, 9
4, 95 ... Magnetic pole tooth end portion, 10 ... Shaft.

Claims (8)

[Claims] 1. A concentrated winding type stator in which a magnetic pole tooth portion of a stator of an electric motor is directly wound with a resin molding insulation, and a height of a magnetic pole tooth end portion of the stator on a slot opening side. Is less than or equal to 1.5 mm, and the thickness of the resin-molded insulation is larger than the resin thickness of the magnetic pole tooth portion on the slot opening side of the magnetic pole tooth end portion. . 2. A concentrated winding type stator in which a magnetic pole tooth portion of a stator of an electric motor is directly wound with a resin molding insulation and a winding is directly wound on the magnetic pole tooth portion of the stator. Is less than or equal to 1.5 mm, and connects the point of the slot side corner on the slot opening side of one magnetic pole tooth end of the magnetic pole tooth and the point of the slot side corner on the root side of the magnetic pole tooth end. A line connecting the extended line of the elbow, the point of the slot side corner of the other magnetic pole tooth end of the magnetic pole tooth end on the slot opening side, and the point of the slot side corner of the root side of the magnetic pole tooth end. The angle formed by the extension line of the magnet is 130 ° or less when viewed from the inner diameter of the stator. 3. When the thickness of the magnetic pole tooth portion of the resin-molded insulation is A, the thickness on the slot opening side of the magnetic pole tooth end portion is 3 A or more when A ≧ 0.5 mm. The permanent magnet type electric motor according to claim 1. 4. When the thickness of the resin-molded insulating magnetic pole tooth portion is A, the thickness of the magnetic pole tooth end portion on the slot opening side is 3 A or more when A ≧ 0.5 mm, and From the root side to the slot opening side of the magnetic pole tooth end, L
The permanent magnet electric motor according to claim 1 or 2, wherein the resin-molded insulation is formed in a V shape. 5. The material of the resin molding insulation is super engineering plastic (super engineering plastic).
The permanent magnet type electric motor according to any one of claims 1 to 4. 6. The permanent magnet type electric motor according to claim 1, wherein the resin molding insulation is integrally resin molded by mounting a stator core on a resin filled mold. 7. The permanent magnet type electric motor according to claim 1, wherein the permanent magnet is embedded in the rotor, and the axial height of the permanent magnet is made lower than the product thickness of the stator core. Item 7. The permanent magnet electric motor according to any one of items 6. 8. The permanent magnet electric motor according to claim 7, wherein the permanent magnet embedded in the rotor of the permanent magnet electric motor is a rare earth magnet.