JP2003274591A - Concentrated coil dc motor and compressor mounted therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a concentrated coil DC motor, wherein the rotor inertia is enhanced to reduce the vibration and further increase in cost is suppressed. <P>SOLUTION: The concentrated coil DC motor comprises a stator 3 formed by winding coils on a stator core 4 by concentrated winding, and a rotor 2 which rotates inside the stator and has permanent magnets 12 in the slots 11 formed in a rotor core 9. With respect to the DC motor, the lamination thickness of the rotor core is made larger than the lamination thickness of the stator core. The length of the permanent magnets is made smaller than the lamination thickness of the stator core, and the permanent magnets are disposed to lie within the range of the stator core. <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 concentrated winding DC motor comprising a stator having a coil wound in a concentrated winding system and a rotor with a built-in magnet, a compressor equipped with the DC motor, and a refrigerator or air conditioner equipped with the compressor. It is about machines.

[0002]

2. Description of the Related Art Conventionally, in compressors which constitute a refrigerant circuit of refrigerators and air conditioners, miniaturization and improvement of energy efficiency have been demanded. Therefore, a motor used for the compressor is also small and has high output. Has been developed. In this case, a distributed winding type brushless DC motor has been conventionally used as a general compressor motor, but in recent years, a concentrated winding type brushless DC motor has been proposed which can achieve simplification of the manufacturing process, downsizing, and efficiency improvement. Has been done.

FIG. 6 shows a conventional concentrated winding type brushless DC.
A sectional view of the motor 101 is shown. The motor 101 is composed of a stator 102 and a rotor 103, and the stator 102 is composed of a stator core 104 in which electromagnetic steel plates (silicon steel plates) are laminated and a stator coil (not shown).
The stator core 104 is provided with teeth 106,
The tooth portion 106 has a predetermined width, and tooth tip portions 107 are provided on both sides of the tooth portion along the surface of the rotor. The stator coil is directly wound around the tooth portion 106 using the space of the slot portion 108, and the stator 10 is wound by the concentrated series winding method.
2 magnetic poles are formed.

On the other hand, the rotor 103 also has a rotor core 111 formed by laminating electromagnetic steel plates (silicon steel plates). Four cutouts are formed on the outer peripheral portion of the rotor core 111, and four salient pole-shaped magnetic poles 112 are formed between these cutouts. Slots 113 are formed in each magnetic pole 112 and are permanently formed in each slot 113. The magnet 114 is embedded.

The permanent magnet 114 may be an ordinary ferrite magnet, but in order to downsize the motor, B
A magnet having a large H product, that is, a so-called rare earth magnet such as a neodymium magnet made of neodymium, iron, or boron, or a samarium cobalt magnet is used. Also, in the figure, 11
6 is an oil separation plate, 117 is a balance weight, 11
Reference numerals 8 and 119 denote end face members made of a non-magnetic material, which are integrated by a rivet 121.

[0006]

SUMMARY OF THE INVENTION Here, a concentrated-winding type DC is used in a compressor such as a single-cylinder rotary compressor or a reciprocating compressor whose load fluctuation is large during one rotation.
When using a motor, there is a problem that vibration and noise increase due to the magnitude of torque fluctuation. In order to solve such a problem, it is necessary to increase the inertia (inertia) of the rotor 103. For that reason, the laminated thickness of the rotor core 111 is enlarged and the laminated thickness of the stator core 106 is also enlarged as shown in FIG. When the length of the permanent magnet 114 is made equal to the product thickness of the rotor core 111, the stator core 106 and the permanent magnet 1
14 is expanded more than necessary, causing deterioration of motor characteristics and soaring costs.

Further, when the length of the permanent magnet 114 is left unchanged as shown in FIG. 7, iron loss is reduced, but similarly, the stator core 106 is expanded more than necessary and copper loss is increased, which causes a problem of deterioration of characteristics. . In particular, as shown in FIG.
Is lifted and held above the rotor 103, the magnetic flux from the stator 102 escapes to the lower side, which facilitates demagnetization, which has the drawback of increasing the motor current.

Furthermore, as shown in FIG. 8, the laminated thickness of the stator core 106 remains unchanged, and the laminated thickness of the rotor core 111 and the permanent magnet 1
Even if only the length of 14 is enlarged, the permanent magnet 11
No. 4 is expanded more than necessary, the cost rises, and the magnetic flux density is concentrated to increase iron loss.

The present invention has been made in order to solve the above-mentioned conventional technical problems, and a concentrated winding type DC motor which suppresses the cost increase while improving the rotor inertia to reduce the vibration is provided. The purpose is to provide a compressor equipped with it.

[0010]

According to the present invention, a stator having a coil wound around a stator core by a concentrated winding method, and a rotor rotating in the stator and having a magnet in a slot formed in the rotor core are provided. In the concentrated winding DC motor consisting of, the rotor core has a larger laminated thickness than the stator core, so the rotor inertia is improved to reduce vibration, and the maximum motor current is reduced to improve motor characteristics. It is possible to plan. Also,
Since the length of the magnet is smaller than the laminated thickness of the stator core and the magnet is arranged within the range of the stator core, the cost increase can be suppressed.

According to the invention of claim 2, in addition to the above, since the magnet is a rare earth magnet, it is possible to ensure sufficient performance with a relatively small magnet.

According to a third aspect of the present invention, in addition to the above respective aspects, an end face member made of a non-magnetic material is attached to the end face of the rotor core, and a protrusion for entering the slot to position the magnet is formed on the end face member. Therefore, it becomes possible to define the magnet mounting position, which is smaller than the laminated thickness of the rotor core, by the projection of the end face member, and it is possible to prevent the magnet mounting position defect and ensure the motor characteristics.

According to the invention of claim 4, in addition to claim 1 or claim 2, end face members made of a non-magnetic material are attached to both end faces of the rotor core, and one end face member is inserted into the slot to position the magnet. While forming a protrusion for
Since the locking portion for locking the magnet is formed in the slot on the side of the other end surface member of the magnet on the rotor core, the position where the magnet is installed, which is smaller than the laminated thickness of the rotor core, is set to the relationship between the projection of the end surface member and the rotor core. It can be defined by a stop. As a result, it becomes possible to prevent the magnet assembly position defect and ensure the motor characteristics. Particularly, since the weight of the rotor is increased by the amount of the locking portion of the rotor core, the inertia is also improved. Further, since the magnet is locked by the locking portion of the rotor core, the other end surface member may be a normal one, which increases versatility.

According to a fifth aspect of the present invention, in addition to the first or second aspect, end face members made of a non-magnetic material are attached to both end faces of the rotor core, and both end face members are inserted into the slots to position the magnets. Since the respective projections for forming the magnets are formed, the mounting position of the magnet, which is smaller than the laminated thickness of the rotor core, can be defined by the projections on both end surface members. As a result, it becomes possible to prevent the magnet assembly position defect and ensure the motor characteristics. In particular, since it is not necessary to change the rotor core, the versatility of the rotor core is increased.

In the sixth aspect of the invention, when the concentrated winding type DC motor of each of the above inventions is torque controlled by the inverter, the motor current is reduced as described above, so that the operating range is expanded and the efficiency is reduced by the torque control. Will be able to be suppressed.

According to the invention of claim 7, since the concentrated winding type DC motor of each of the above inventions is mounted on a refrigerator or a compressor for an air conditioner, a refrigerator or an air conditioner of high quality and high efficiency with less noise and vibration is provided. It will be something that can be provided.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a plan view (excluding coils) of a concentrated winding brushless DC motor 1 of an embodiment to which the present invention is applied, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG.
It is an enlarged view of the circle A part of. The motor 1 of the embodiment is, for example, a concentrated winding type brushless D mounted as a drive motor of a single-cylinder rotary compressor or a reciprocating compressor that constitutes a refrigerant circuit of a refrigerator or an air conditioner.
It is a C motor, and is composed of a stator 3 and a rotor 2 that rotates in the stator 3, and torque control is performed by an inverter.

The stator 3 comprises a stator core 4 formed by laminating electromagnetic steel plates (silicon steel plates) and the stator core 4
And a stator coil (not shown) wound around the. The stator core 4 is provided with teeth 6 having a predetermined width, and the tips of the teeth 6 are extended to both sides to form teeth tips 7 along the surface of the rotor 2. Then, a stator coil (not shown) is directly wound around the tooth portion 6 using the space of the slot portion 8 to form the magnetic pole of the stator 3 by the concentrated series winding method.

As shown in FIG. 1, a part P1 and P2 of the tooth tip portion 7 is cut and removed (in the figure, P1 and P2 are shown one by one, but all tooth tip portions are shown). Part 7 is similarly cut). The cut portion is only the tooth tip 7 in the direction in which the rotor 2 rotates, for example, P1.
Although one side is sufficient, the other end P2 of the tooth tip portion 7 is also cut so that the rotor 2 can be inserted from either direction of the stator 3 when the motor is assembled. In this way, even if the tooth tip portions 7 on both sides are cut, the influence on the torque characteristics of the motor is negligible.

With this configuration, the distance from the rotor 2 does not become evenly spaced along the outer peripheral surface of the rotor 2, so that the distance from the rotor 2 is cut off at the tooth tip portion 7. By increasing the magnetic resistance, the magnetic resistance in the cut portion increases, and the magnetic flux is averaged without concentration at the tooth tip 7 in the direction in which the rotor 2 rotates.

Without this cut, the peak value of the force acting on the center side of the rotor core 9 (described later) of the rotor 2 of the motor 1 becomes large, the width of the change in the force becomes large, and the temporal fluctuation rate becomes large. Increase and cause vibration of the motor. On the other hand, when there is a cut, the peak value does not increase and the curve becomes a comparatively gentle curve. Therefore, the width of change in force is reduced and the temporal fluctuation rate is also reduced. Can be suppressed.

As a result, the relationship between the rotor rotation angle and the torque of the motor 1 becomes a smooth waveform with less harmonic components, the fluctuation of the torque can be reduced, and the vibration during the rotation of the motor 1 can be reduced. .

On the other hand, the rotor 2 has a rotor core 9 formed by laminating similar electromagnetic steel plates (silicon steel plates), and permanent magnets 12 embedded in slots 11 formed in the rotor core 9. And an end face member 1 made of a non-magnetic material
3, 14, balance weight 16, and oil separating plate 17
, And these are integrated by the rivet 18 (FIG. 2).

In this case, the laminated thickness of the rotor core 9 of the rotor 2 is larger than the laminated thickness of the stator core 4 of the stator 3 (FIG. 3). Further, the length of the permanent magnet 12 is smaller than the laminated thickness of the stator core 4. Further, the upper and lower end face members 13, 14 are formed by cutting and raising projections 13A, 14A which enter into the slots 11, ..., And these projections 13A, 14A are formed on the permanent magnets 12 as shown in FIG. It abuts the lower surface and holds each permanent magnet 12 immovably in the slot 11.

In this case, the protrusions 13 of the end face members 13 and 14
A and 14A have the same length, whereby the permanent magnet 12 is arranged within the range of the stator core 4, and
The center of the permanent magnet 12 is the rotor core 9 and the stator core 4
It is specified to match the axial center of the. With such a configuration, the magnetic flux from the stator 3 comes out evenly above and below the permanent magnet 12, which makes it difficult to demagnetize.

The permanent magnet 12 may be an ordinary ferrite magnet, but in order to downsize the motor, BH is used.
A so-called rare earth magnet such as a magnet having a large product, that is, a neodymium magnet made of neodymium, iron, or boron, or a samarium cobalt magnet is used.

As described above, since the laminated thickness of the rotor core 9 is made larger than that of the stator core 4, the inertia of the rotor 2 is improved to reduce the vibration, and the maximum value of the motor current is reduced to improve the motor characteristics. It is possible to improve. Further, since the length of the permanent magnet 12 is made smaller than the laminated thickness of the stator core 4 and arranged within the range of the stator core 4, it is possible to suppress the cost increase.

Further, if the permanent magnet 12 is the above-mentioned rare earth magnet, it is possible to secure sufficient performance with a relatively small permanent magnet.

Further, the end surface members 13 and 14 of the rotor 2 are
Since the projections 13A and 14A for positioning the permanent magnet 12 by entering the slot 11 are formed, the installation position of the permanent magnet 12 smaller than the product thickness of the rotor core 9 is set to the projection 13A of the end surface members 13 and 14. , 14A, it becomes possible to prevent a defective assembly position of the permanent magnet 12 and secure the motor characteristics.

Particularly, the projections 13A of the end surface members 13 and 14,
If the weight of the rotor is increased by 14A, the inertia of the rotor 2 is improved. Further, in this case, since it is not necessary to provide the rotor core 9 itself with a structure for holding the permanent magnet 12, the versatility of the rotor core 9 is increased.

Next, FIGS. 4 and 5 show another embodiment of the present invention. In each figure, the same reference numerals as those in FIGS. 1 to 3 have the same or similar functions. In this case, the protrusion 13A is formed on the one (upper) end surface member 13, but the protrusion is not formed on the other (lower) end surface member 14. Instead, the rotor core 9 of the slot 11 portion located on the end face member 14 side of the permanent magnet 12 is provided with a locking portion 9A that projects toward the slot 11 side.

As shown in FIG. 5, this locking portion 9A is provided with a slot 11
All or a part of both surfaces or one surface of the rotor core 9 facing toward the slot 11 is projected toward the slot 11 side (for example, the inner size of one slot of the electromagnetic steel plate is reduced).

In this case, from the length of the protrusion 13A of the end surface member 13 and the surface of the rotor core 9 on the end surface member 14 side, the locking portion 9A is formed.
Up to the same size, which results in permanent magnets 12
Is arranged within the range of the stator core 4, and the center of the permanent magnet 12 is defined so as to coincide with the axial center of the rotor core 9 and the stator core 4. With such a configuration, similarly, the magnetic flux from the stator 3 comes out evenly above and below the permanent magnet 12, which makes it difficult to demagnetize.

As described above, in the embodiment in this case, one end face member 13 is inserted into the slot 11 and the permanent magnet 12 is inserted.
13A is formed on the rotor core 9 in order to form the protrusion 13A for positioning the permanent magnet 12 and the slot 11 on the other end face member 14 side of the permanent magnet 12 is formed on the rotor core 9 for engaging the permanent magnet 12. The installation position of the permanent magnet 12 which is smaller than the laminated thickness of the
3A and the locking portion 9A of the rotor core 9 can be used.

As a result, it becomes possible to prevent a defective assembly position of the permanent magnet 12 and ensure motor characteristics. In particular, since the weight of the rotor 2 is increased by the amount of the engaging portion 9A of the rotor core 9, the inertia is also improved. Further, since the permanent magnet 12 is locked by the locking portion 9A of the rotor core 9, the other end surface member 14 may be a normal one, which increases versatility.

In any case, when controlling the torque of the concentrated winding DC motor 1 by the inverter, the motor current is reduced as described above, so that the operating range is expanded and the efficiency reduction due to the torque control is suppressed. Will be able to.

Further, by mounting the concentrated winding DC motor 1 in a refrigerator or a compressor for an air conditioner, it is possible to provide a high quality and high efficiency refrigerator or air conditioner with less noise and vibration. become.

[0038]

As described in detail above, according to the present invention, a stator in which a coil is wound around a stator core by a concentrated winding method, and a magnet is inserted into a slot formed in the rotor core while rotating in the stator. In a concentrated winding DC motor including a rotor provided with the rotor core, the rotor core has a larger laminated thickness than the stator core. Therefore, the rotor inertia is improved to reduce vibration, and the maximum motor current is reduced to improve the motor characteristics. Can be improved.
Further, since the length of the magnet is smaller than the laminated thickness of the stator core and the magnet is arranged within the range of the stator core, it is possible to suppress the cost increase.

According to the invention of claim 2, in addition to the above, since the magnet is a rare earth magnet, it is possible to secure sufficient performance with a relatively small magnet.

According to the invention of claim 3, in addition to each of the above inventions, an end face member made of a non-magnetic material is attached to the end face of the rotor core, and the end face member is inserted into the slot to position the magnet. Since the magnet is formed, it becomes possible to define the magnet mounting position, which is smaller than the laminated thickness of the rotor core, by the projection of the end surface member, and it is possible to prevent the magnet mounting position from being defective and ensure the motor characteristics.

According to the invention of claim 4, in addition to claim 1 or claim 2, end face members made of a non-magnetic material are attached to both end faces of the rotor core, and one end face member is inserted into the slot and magnetized. Since a protrusion for positioning the magnet is formed, and a locking portion for locking the magnet is formed in the slot on the side of the other end surface member of the magnet on the rotor core, a magnet smaller than the laminated thickness of the rotor core is formed. The mounting position can be defined by the protrusion of the end surface member and the locking portion of the rotor core. As a result, it becomes possible to prevent the magnet assembly position defect and ensure the motor characteristics. Particularly, since the weight of the rotor is increased by the amount of the locking portion of the rotor core, the inertia is also improved. Further, since the magnet is locked by the locking portion of the rotor core, the other end surface member may be a normal one, which increases versatility.

According to the invention of claim 5, in addition to claim 1 or claim 2, end face members made of a non-magnetic material are attached to both end faces of the rotor core, and magnets are inserted into both end face members to enter the slots. Since the protrusions for positioning are respectively formed, the magnet mounting position, which is smaller than the laminated thickness of the rotor core, can be defined by the protrusions on both end surface members. As a result, it becomes possible to prevent the magnet assembly position defect and ensure the motor characteristics. In particular, since it is not necessary to change the rotor core, the versatility of the rotor core is increased.

According to the invention of claim 6, when controlling the torque of the concentrated winding type DC motor of each of the inventions by the inverter, the motor current is reduced as described above.
The operating range is expanded, and it is possible to suppress a decrease in efficiency due to torque control.

According to the invention of claim 7, since the concentrated winding type DC motor of each of the above inventions is mounted in a refrigerator or a compressor for an air conditioner, a refrigerator or an air conditioner of high quality and high efficiency with less noise and vibration is provided. Machine will be able to be provided.

[Brief description of drawings]

FIG. 1 is a plan view of a concentrated winding brushless DC motor according to an embodiment of the present invention.

2 is a cross-sectional view of the motor of FIG. 1 taken along the line AOA.

FIG. 3 is an enlarged view of a circle A portion of FIG.

FIG. 4 is a cross-sectional view of another embodiment of the motor shown in FIG.

5 is an enlarged view of a circle A portion of FIG.

FIG. 6 is a sectional view of a conventional motor.

FIG. 7 is a sectional view of another conventional motor.

FIG. 8 is a cross-sectional view of yet another conventional motor.

[Explanation of symbols]

1 motor 2 rotor 3 stator 4 Stator core 6 teeth 7 Tooth tip 9 Motor core 9A locking part 11 slots 12 permanent magnet 13, 14 End face member 13A, 14A protrusion

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 29/06 H02K 29/06 Z (72) Inventor Toshito Yanjima Keihanhondori 2-chome, Moriguchi City, Osaka Prefecture 5-5 Sanyo Denki Co., Ltd. (72) Inventor Keijiro Igarashi 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Denki Co., Ltd. F-term (reference) 3H003 AA00 AB00 AC03 CF04 5H002 AA07 AA08 AB08 AC03 AC06 AC08 5H019 AA02 AA06 AA10 CC03 DD01 EE01 5H621 AA02 BB07 GA01 GA04 HH01 5H622 AA02 CA02 CA05 CB01 CB04 DD02 PP03 PP11

Claims (7)

[Claims] 1. A concentrated winding DC motor comprising a stator having a coil wound around a stator core in a concentrated winding system, and a rotor rotating in the stator and having a magnet in a slot formed in the rotor core. The concentrated winding is characterized in that a laminated thickness of the rotor core is made larger than a laminated thickness of the stator core, a length of the magnet is made smaller than a laminated thickness of the stator core, and the magnets are arranged within a range of the stator core. DC motor. 2. The concentrated winding DC motor according to claim 1, wherein the magnet is a rare earth magnet. 3. An end face member made of a non-magnetic material is attached to an end face of the rotor core, and a protrusion for entering the slot and positioning the magnet is formed on the end face member. 1 or claim 2 concentrated winding type D
C motor. 4. An end face member made of a non-magnetic material is attached to both end faces of the rotor core, and one end face member is formed with a protrusion for entering the slot to position the magnet, The concentrated winding DC motor according to claim 1 or 2, wherein a locking portion for locking the magnet is formed in the slot on the side of the other end surface member on the rotor core. 5. An end surface member made of a non-magnetic material is attached to both end surfaces of the rotor core, and both end surface members are formed with protrusions for entering the slot and positioning the magnet. The concentrated winding DC motor according to claim 1 or 2. 6. The torque control is performed by an inverter, claim 1, claim 2, claim 3, claim 4.
Alternatively, the concentrated winding DC motor according to claim 5. 7. A compressor for a refrigerator or an air conditioner equipped with the concentrated winding DC motor according to claim 1, claim 2, claim 3, claim 4, claim 5 or claim 6.