JP2003143822A - Induction motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a traverse current and loss, and to improve efficiency by using coil winding as the conductor of a rotor in a four-pole induction motor. SOLUTION: Eight grooves 1b are formed at an equal interval in a circumferential direction in a four-pole rotor 1 that is arranged at the inside of a stator for generating a rotary magnetic field, at the same time the direction of the grooves 1b is formed in an axial direction of a rotary axis 2, two wires 3a and 4a of first and second groups of wires 3 and 4 that become short-circuiting conductors are overlapped and wound at every two pitches each, and at the same time the first and second groups of wires 3 and 4 are allowed to be adjacent each other. At the side of the stator, wires for generating a rotary magnetic field are provided, and an induced short-circuiting current flows from the rotary magnetic field to the short-circuiting wires (two short-circuiting conductors) 3a and 4a in reverse directions each. Due to the interaction between the rotary magnetic field by the stator and the induced short-circuiting current, rotary force in the same rotary direction operates on the two short-circuiting conductors and the rotor 1 is rotated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a four-pole induction motor used for consumer equipment (for example, air conditioners) and industrial equipment, and more particularly to a novel induction motor using a winding as a rotor conductor. It is a thing.

[0002]

2. Description of the Related Art An induction motor has a rotor arranged inside a stator that generates a rotating magnetic field. The stator is provided with windings for generating a rotating magnetic field. Has no fixed magnetic poles, that is, no winding like the stator winding is provided.

When the rotor having the short-circuit conductor is arranged in the rotating magnetic field of the stator, a short-circuit induced current flows through the rotor. Rotational force (torque) is generated by the interaction between the rotating magnetic field and the induced short-circuit current, and the rotor rotates. Such induction motors are widely used for home appliances and industrial equipment from the viewpoints of simplicity and economy.

[0004]

By the way, conventionally, the main body (short-circuit conductor) of the rotor is manufactured mainly by casting the conductor by aluminum die casting.

However, since it is difficult to insulate the rotor core from the aluminum conductor, a transverse current (current flowing in the circumferential direction of the rotor core) that does not contribute to torque is applied to the rotor core.
However, there is a drawback in that this causes an increase in loss and reduces the efficiency of the motor.

Further, since it is difficult to use copper having high electric conductivity as the conductor, since aluminum conductor is used, electric loading and magnetic loading are small, resulting in shortage of torque and low efficiency. there were.

The present invention has been made to solve the above problems, and an object thereof is to adopt a winding method using a winding as a conductor of a rotor to eliminate a transverse current and reduce a loss. The purpose of the present invention is to provide an induction motor having improved efficiency and, as a result, a wider range of use as a 4-pole motor.

[0008]

In order to achieve the above object, the present invention provides a four-pole induction motor in which a rotor is arranged inside a stator that generates a rotating magnetic field. The first and second winding groups consisting of the windings are used and the windings of the first and second winding groups are overlapped, respectively, and an induced short-circuit current is generated in the windings by the rotating magnetic field. It is characterized by making it flow.

The rotor is formed with 2 × 2 × n (n: positive integer of 2 or more) grooves at equal intervals in the axial direction of the rotary shaft of the rotor and in the circumferential direction, The windings of the first and second winding groups are respectively n pitched through these grooves.
It is preferable that the first winding group and the second winding group are adjacent to each other while individual pieces are provided. As a result, grooves of an integral multiple of 4 can be formed on the rotor.

Further, the rotor has 2 × (2 × n + 1).
(N: a positive integer of 2 or more) grooves are formed at equal intervals in the axial direction of the rotation axis of the rotor and in the circumferential direction, and the first and second windings are formed through these grooves. N + 1 for each line group
In addition to n pitches, an empty groove may be provided between both ends of the first and second winding groups or in the center thereof. As a result, an even number of grooves other than the integral multiple of 4 can be formed in the rotor.

On the other hand, the stator located on the outer peripheral side of the rotor is provided with a main winding and an auxiliary winding, and
By applying those windings in concentrated winding or distributed winding,
The induction motor can be a capacitor induction motor.

Further, eight grooves are formed on the inner peripheral side of the stator located on the outer peripheral side of the rotor, and the main winding and the auxiliary winding are concentratedly wound through these grooves. Also, the induction motor can be a capacitor induction motor. According to this, a highly efficient capacitor induction motor using a novel rotor can be realized, and the range of use of the capacitor induction motor can be expanded.

The stator located on the outer peripheral side of the rotor is provided with three-phase windings, and the windings are concentrated or distributed to make the induction motor a three-phase AC induction motor. can do.

Further, by forming 12 grooves on the inner peripheral side of the stator located on the outer peripheral side of the rotor, and performing concentrated winding of three-phase winding through these grooves, The induction motor can be a three-phase AC induction motor. As a result, a highly efficient three-phase AC induction motor using a novel rotor can be realized, and the range of use of the three-phase AC induction motor can be expanded.

It is preferable that all the windings applied to the rotor are short-circuited windings. Aluminum or aluminum alloy, copper or copper alloy is used for all the windings applied to the rotor, and the windings are connected by pressure welding, welding, soldering or crimping with crimp terminals. Is preferably adopted.

As a result, it is possible to use a copper-based material as the winding of the short-circuit conductor of the rotor, that is, high torque and high efficiency can be achieved, and the connection of the short-circuit winding can be achieved by existing technology. Can be realized with.

It is preferable to electrically insulate between the windings provided through the grooves of the rotor. Similarly, it is preferable to electrically insulate between the rotor core and the winding of the rotor. Further, the groove of the rotor may be an open hole or a closed groove.

As a result, when the induced short-circuit current flows through the winding, the induced short-circuit current does not flow through the rotor core of the rotor, that is, the transverse current is extremely small, the loss is small, and the efficiency is high. .

The rotor is preferably obtained by punching electromagnetic steel sheets with an automatic laminating die and laminating the rotor cores to obtain a rotor core, and skewing the grooves during the lamination. According to this, the short-circuit winding as the short-circuit conductor of the rotor is provided in the skewed groove, and the torque can be improved.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Next, an embodiment of the present invention will be described in detail with reference to FIGS. The induction motor of the present invention is basically a four-pole motor, and this rotor forms 2 × 2 × n (n; a positive integer of 2 or more) grooves on the outer circumference of the rotor core. A first winding group in which n pitch windings (closed circuit of short-circuit winding; hereinafter referred to as short-circuit winding) is applied to n grooves, and n short-circuit windings are overlapped, and the first winding group. The second winding group having the same structure is provided adjacent to the second winding group to provide 2 × n windings.

First, the first embodiment will be described in detail. As shown in FIGS. 1 and 2, the rotor 1 of this induction motor has a rotor core (rotor iron core) 1a on the outer peripheral side.
(N = 2) grooves 1b are formed at equal intervals in the axial direction of the rotary shaft 2 and in the circumferential direction, and two 2-pitch short-circuit windings 3a are superposed through the eight grooves 1b. To form a first winding group 3 and to form a second winding group 4 by continuously wrapping two short pitch windings 4a of 2 pitches on the first winding group 3. It is made by winding individual pieces.

As shown in FIGS. 3 and 4, eight grooves are formed on the inner peripheral side of the stator 5 of this induction motor. That is, twelve teeth 5b having a predetermined width are formed inside the yoke portion 5a on the outer peripheral side at intervals of 45 degrees, and
These teeth 5b have concentrated windings 6a, 6b, 6c, 6
d, 7a, 7b, 7c, 7d are provided, and the windings 6a, 6b and the windings 6c, 6d are provided on the opposing teeth 5b.
2 pairs of the main windings and the remaining teeth 5b on the winding 7a,
Two pairs of 7b and windings 7c and 7d are used as auxiliary windings.

In the induction motor having the above structure, in order to generate a rotating magnetic field in the stator 5, for example, as shown in FIG. 4, the main windings 6a, 6b, 6c, 6d and the auxiliary winding 7a,
Connect 7b, 7c and 7d.

That is, the parallel circuit of the auxiliary windings 7a, 7b and the auxiliary windings 7c, 7d and the capacitor 8 are connected in series, and the main windings 6a, 6b and the main windings 6c, 6d are connected to the series circuit. The parallel circuits are connected in parallel, and the AC power supply 9 is supplied to the parallel circuits. The main winding and the auxiliary winding may be connected by another connection method.

As a result, the induction motor becomes a capacitor induction motor. In this capacitor induction motor, when a rotating magnetic field is generated in the stator 5, an induced short-circuit current flows in the short-circuit windings 3a and 4a of the rotor 1 due to this rotating magnetic field. There are two short-circuit conductors formed by these short-circuit windings 3a and 4a, and the induced short-circuit currents of these two short-circuit conductors flow in opposite directions.

Therefore, due to the interaction between the rotating magnetic field generated by the windings shown in FIGS. 3 and 4 and the induced short-circuit current, the two short-circuit conductors formed by the short-circuit windings 3a and 4a respectively have a rotational force (torque) in the same rotation direction. ) Works to rotate the rotor 1.

In the first embodiment, the rotor 1 has eight grooves, but 2 × 2 × n grooves are formed.
Even if 2n windings are formed by the first winding group including n windings and the second winding group including n windings, the same action and effect can be obtained. it can. Further, although the concentrated winding is used as the winding of the stator 5, it may be distributed winding.

As a method of manufacturing the rotor 1, electromagnetic steel plates (belt-shaped) are punched and laminated by an automatic laminating die. At this time, the rotor core 1a is obtained by skewing the grooves 1b. Is preferred. As a result, the short-circuit windings 3a and 4a are skewed, and the torque of the capacitor induction motor can be increased.

The groove 1b of the rotor 1 is preferably an open hole as shown in FIG. 1 in view of easiness of manufacturing the rotor 1, but it may be a closed hole. It is preferable that the inside of the groove 1b be insulated. That is, by electrically insulating between the rotor core 1a and the short-circuit windings 3a and 4a, the space between the rotor core 1a and the short-circuit winding 3a and between the rotor core 1a is reduced.
And the short-circuited winding 4a are electrically insulated from each other, the transverse current becomes as small as possible, the loss does not increase, and the efficiency of the motor can be improved.

Further, the short-circuit winding 3a formed in each groove 1b
Also, by using a winding in which an insulating film is applied to the short-circuit winding 4a with enamel or the like to insulate the wires, it is possible to further suppress the transverse current and the loss.

Aluminum, aluminum alloy, copper, or copper alloy is used for the short-circuit conductors of the short-circuit windings 3a, 4a of the rotor 1, and the connection method is pressure welding, welding, soldering, or crimping with crimp terminals. It is preferable to adopt

As a result, when a copper-based material is used for the short-circuit windings 3 and 4a, higher torque and higher efficiency can be expected as compared with the aluminum-based material. Existing technology can be used.

Here, supplementary description will be given of the short-circuit windings 3a and 4b of the rotor 1. Since the windings form a short-circuit circuit, they are induced if the space factor or the usage amount is the same. Ampere-turn TA generated by voltage
Is constant.

Explaining the reason for this, the voltage induced in the short-circuit winding 3 is expressed by the following formulas 1 and 2.

[0035]

[Equation 1]

[0036]

[Equation 2]

N is the number of groove conductors, and the rotor groove conductor cross-sectional area is a value obtained by multiplying the square of the conductor diameter d by the number N of conductors (constant).
Where φ is the main magnetic flux (constant), R is the winding resistance,
X is the reluctance of the winding.

When the number of groove conductors is one (N = N1 =
1), the ampere-turn TA1 can be represented by i1 · N1, and when the number of groove conductors is plural (N = N2), the ampere-turn T
A2 can be represented by i2 · N2.

Comparing the ampere-turns TA1 and TA2, TA2 / TA1 = 1 according to the following equation (3).

[0040]

[Equation 3]

In the above formula 3, when the number of groove conductors is one, the diameter of the winding wire to be applied to the groove is increased, and the winding amount to be applied when the number of groove conductors to be used is plural. By setting the same as the used amount, the ampere-turn TA becomes the same when the number of groove conductors is plural and when the number of groove conductors is one.

Therefore, if the rotor groove conductor cross-sectional areas, that is, the space factors, are made equal, the motor performance is the same regardless of whether there is one winding or a plurality of windings. It can be said that the torque characteristic of the induction motor by the rotor 1 according to the invention is equivalent to that of the die cast rotor.

Next, a three-phase four-pole induction motor as a second embodiment shown in FIGS. 5 to 7 will be described. The same parts as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted.

The rotor of the induction motor according to the second embodiment has 2 × (2n +) on the outer peripheral side of the rotor core (rotor core).
1) (n; positive integer of 2 or more) grooves are formed,
Winding of n pitches (closed circuit of short-circuit winding; hereinafter referred to as short-circuit winding) is applied to x (2n + 1) grooves, and n
The first winding group in which the short-circuited windings are overlapped and the second winding group having the same structure adjacent to the first winding group are formed by arranging one slot (groove), and 2 × N windings are applied.

More specifically, as shown in FIG.
The rotor 10 of this induction motor has a rotor 10 (rotor core) on the outer peripheral side, as in the rotor 1 of the first embodiment.
(N = 2) grooves are formed at equal intervals in the axial direction of the rotary shaft and in the circumferential direction, and a first winding group composed of two short-circuit windings 11a via these ten grooves. A second winding group 12 including 11 and two short-circuited windings 12a is formed by placing one slot (groove).

In this case, the first winding group 11 is formed by stacking two short pitch windings 11a having two pitches by overlapping one slot.
The second winding group 12 is formed by stacking two short-circuit windings of two pitches for one slot.

As shown in FIGS. 6 and 7, the stator 13 of this induction motor is formed with 12 grooves, that is, the teeth 13b having a predetermined width are provided inside the yoke portion 13a on the outer peripheral side at 30 degrees. 12 teeth are formed at intervals, and windings 14a, 14b, 14c, 14d, 15a of concentrated winding are formed on these teeth 13b.
15b, 15c, 15d, 16a, 16b, 16c, 1
6d is applied.

Regarding the above-mentioned twelve windings 14a to 16b, the windings 14a and 14b formed on the teeth 12b facing each other.
And two pairs of windings 14c and 14d are U-phase windings, two pairs of windings 15a and 15b and windings 15c and 15d are V-phase windings, and windings 16a and 16b and winding 1
Two pairs of 6c and 16d are W-phase windings.

In the induction motor of the second embodiment, in order to generate a rotating magnetic field in the stator 13, as shown in FIG. 7, twelve windings 14a to 16d are Y-connected, and the Y-connection is performed. Supply three-phase AC power to the winding.

In this case, for the U phase, the windings 14a, 1
4b and windings 14c and 14d are connected in parallel, for the V phase, windings 15a and 15b and windings 15c and 15d are connected in parallel, and for the W phase, windings 16a and 16b and winding 16c, 16d and 16d are connected in parallel. The windings may be connected by another connection method.

As a result, the induction motor becomes a 3-phase 4-pole induction motor. In this three-phase, four-pole induction motor, when a rotating magnetic field is generated in the stator 13, an induced short-circuit current flows in the short-circuit windings 11a and 12a of the rotor 10 due to this rotating magnetic field. The short-circuit winding 11a and the short-circuit winding 1
2a are two short-circuit conductors, respectively, and these short-circuit conductors operate in the same manner as in the first embodiment described above. Therefore, due to the interaction between the rotating magnetic field and the induced short-circuit current by the windings shown in FIGS. Rotational forces (torques) in the same rotational direction act on the two short-circuit conductors formed by the winding 11a and the two short-circuit conductors formed by the short-circuit winding 12a, respectively.
Rotates.

In this embodiment, the number of grooves of the rotor 10 is set to 10. However, even if the number of grooves of 2 × (2n + 1) is formed and 2n windings are formed on it, the same operation,
The effect can be obtained. Although the concentrated winding is used as the winding of the stator 12, it may be distributed winding.

The rotor 10 and the stator 12 may be manufactured in the same manner as in the first embodiment. For example, the groove (open hole or closed hole) of the rotor 10 is skewed and its groove ( It is preferable that the inside of the opening or the closed hole is electrically insulated.

The short-circuit windings 11a, 12 of the rotor 10 are also
Also for a, it is preferable to use the material and connection method described in the first embodiment and to insulate. Therefore, also in the second embodiment, the same effect as that of the first embodiment can be obtained.

As described above, by adopting the winding method using the copper wire or the aluminum wire for the short-circuit conductor of the rotor, the transverse current explained in the conventional example is extremely small, the loss is small, and the motor efficiency is high. improves.

FIG. 8 is a schematic diagram of a rotor showing a modification of the second embodiment. According to this modification, the rotor 20 of the 4-pole induction motor has the same structure as in the first embodiment.
10 (n = 2) grooves are formed at equal intervals in the axial direction of the rotary shaft and in the circumferential direction, and the first winding consisting of two short-circuit windings 21a via these 10 grooves. A second winding group 22 including a group 21 and two short-circuit windings 22a is formed adjacent to each other.

In this case, the first winding group 21 has 3
The short-circuit winding 21a having a pitch is overlapped by two for one slot, and the second winding group 22 is formed by overlapping two short-circuit windings with a pitch of three for one slot.

As the short-circuit conductors of the short-circuit windings 21a and 22a of the rotor 20, four short-circuit conductors are continuous and
Four short-circuit conductors are continuous with one groove provided, that is, the short-circuit conductors are arranged in the same manner as in the second embodiment.

Therefore, if a stator having the same structure (U-phase, V-phase, and W-phase winding structure) as the stator 13 of the second embodiment is used, the rotating magnetic field is generated in the short-circuit winding 21a and the short-circuit winding 22a. As a result, an induced short-circuit current flows, and the rotor 20 rotates due to the same action as in the second embodiment.

As described above, in this modification, at least the operation and effect described in the second embodiment can be obtained. That is, the difference between this modification and the second embodiment is that a groove (empty groove 5, 10) not provided with a short-circuit winding is provided at the center of the first winding group 21 and the center of the second winding group 22. 5 (see FIG. 5) or the empty grooves 3 and 8 are provided on the end side of the first winding group 21 and the end side of the second winding group 22 (see FIG. 8). , This difference is not essential.

Although the number of grooves of the rotor 20 is 10, the same action and effect can be obtained by forming 2 × (2n + 1) grooves and providing 2n windings. For example, when n = 5 is used and a rotor having 10 windings through 22 grooves is used, low vibration and low noise of the motor can be achieved.

[0062]

According to the four-pole induction motor of the present invention, the first and second winding groups are used as the short-circuit conductors of the rotor inside the stator, and the first and second winding groups are formed. The winding currents in the rotor are extremely small compared to short-circuit conductors made by aluminum die-casting, because multiple windings are wound on top of each other, and induced short-circuit currents are made to flow through those windings by the rotating magnetic field of the stator. However, there is a useful effect that loss is small, high efficiency can be improved, and the range of use can be expanded as a 4-pole motor.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a rotor of an induction motor according to a first embodiment of the present invention as seen from a rotation axis direction thereof.

FIG. 2 is a schematic diagram for explaining a winding connection state of the rotor shown in FIG.

FIG. 3 is a schematic side view of the stator side of the induction motor according to the first embodiment seen from the rotation axis direction of the rotor.

4 is a schematic circuit diagram for explaining a winding connection state of the stator shown in FIG.

FIG. 5 is a schematic diagram for explaining a winding connection state of the rotor of the induction motor according to the second embodiment of the present invention.

FIG. 6 is a schematic side view of a stator side of an induction motor according to a second embodiment of the present invention as seen from a rotation axis direction of a rotor.

7 is a schematic circuit diagram for explaining a winding connection state of the stator shown in FIG.

FIG. 8 is a schematic diagram for explaining a winding connection state of a rotor according to a modified example of the second embodiment.

[Explanation of symbols]

1,10,20 Rotor 1a Rotor core (rotor core) 1b Groove 2 Rotating shafts 3a, 4a Short-circuit winding (conductor of rotor 1; winding of closed circuit) 3,11,21 First winding group 4 , 12, 22 Second winding group 5, 13 Stator 5b, 13b Teeth 6a-6d, 7a-7d Winding 11a, 12a of stator 5 Short-circuited winding (conductor of rotor 10; winding of closed circuit) ) 14a to 14d, 15a to 15d, 16a to 16d Windings 21a and 22a of the stator 13 Short-circuited windings (conductors of the rotor 20; windings of closed circuit)

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H02K 17/12 H02K 17/12 AF Term (reference) 5H013 DD03 FF03 LL00 LL05 MM00 NN01 NN05 NN06 PP01 PP03 5H603 AA01 BB01 BB06 BB07 BB08 BB12 CA01 CA02 CA06 CB01 CB02 CB23 CB26 CC04 CC05 CC11 CC17 CD05 CD21 CE01 CE13 CE14 CE16 EE01 5H604 BB01 BB09 BB14 CC05 CC13 CC14 CC15 CC16 PB02 PB03

Claims (13)

[Claims] 1. A four-pole induction motor in which a rotor is arranged inside a stator that generates a rotating magnetic field, wherein first and second winding groups each including a plurality of windings are used as conductors of the rotor. An induction motor characterized in that the windings of the first and second winding groups are respectively wound in layers, and an induced short-circuit current flows through the windings by the rotating magnetic field. 2. The rotor is formed with 2 × 2 × n (n: a positive integer of 2 or more) grooves at equal intervals in the axial direction of the rotating shaft and in the circumferential direction. The first winding group and the second winding group are arranged adjacent to each other while providing n windings of each of the first and second winding groups at a pitch of n through a groove. Induction motor described. 3. The rotor is formed with 2 × (2 × n + 1) (n; a positive integer of 2 or more) grooves at equal intervals in the axial direction of the rotating shaft and in the circumferential direction, The first and second winding groups are each provided n times at a pitch of n + 1 through these grooves, and a vacant groove is provided between both ends of the first and second winding groups or in the center thereof. The induction motor according to 1. 4. The stator according to claim 1 or 2, wherein the stator is provided with a main winding and an auxiliary winding, and the windings are concentrated or distributed so that the induction motor is a capacitor induction motor. Induction motor. 5. The inner peripheral side of the stator is provided with eight grooves, and main windings and auxiliary windings are concentratedly wound through these grooves to make the induction motor a capacitor induction motor. The induction motor according to claim 1 or 2. 6. The induction motor is a three-phase AC induction motor, wherein the stator is provided with three-phase windings and the windings are concentrated or distributed windings.
Induction motor described in. 7. The induction motor is a three-phase AC induction motor, in which 12 grooves are formed on the inner peripheral side of the stator and three-phase windings are concentratedly wound through these grooves. The induction motor according to Item 1 or 3. 8. The induction motor according to claim 1, wherein all the windings applied to the rotor are short-circuited windings. 9. All of the windings applied to the rotor are made of aluminum, aluminum alloy, copper or copper alloy, and the windings are connected by crimping, welding, soldering or crimping with crimp terminals. The induction motor according to any one of claims 1 to 8, wherein any one of the above is adopted. 10. The induction motor according to claim 2, wherein electrical insulation is provided between windings provided through the groove of the rotor. 11. The induction motor according to claim 2, wherein the rotor core of the rotor and the winding are electrically insulated. 12. The induction motor according to claim 2, wherein the groove of the rotor is an open hole or a closed groove. 13. The rotor according to claim 2, wherein an electromagnetic steel plate is punched by an automatic laminating die and laminated to obtain a rotor core, and a groove is skewed during the laminating. Induction motor.