JP3099832B2 - 2 stator induction motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates relates to the induction motor 2 stator structure constituted by a single rotor and two stator, in particular the start of a high-torque, smoothly from start to running torque The present invention relates to a two- stator induction motor that can be changed.

[0002]

2. Description of the Related Art A known technique for improving starting torque and its characteristics by an induction motor having a plurality of stators is disclosed in, for example, Japanese Patent Application Laid-Open No. 54-29005.
The two stators have two independent stator windings opposed to the two rotor cores, and are commonly installed across the two rotor cores. And a high-resistance element that short-circuits the cage conductors at the center of the cage conductor between the two sets of rotor cores. This twin-cage electric motor is characterized in that the phases of the wires are shifted by 180 ° and power is supplied in phase during operation after startup. This motor improves the starting characteristics by increasing the starting torque by shifting the phase between the stator windings by 180 ° at the time of starting, and matches the phase between the stator windings during operation to increase the normal torque. It can be operated with characteristics.

[0003] In Japanese Patent Application Laid-Open No. 54-19005, a shock generated by a sudden change in torque accompanying a shift from start-up to steady-state operation is inevitable. In order to mitigate this shock, the connection of both stator windings to the feeder circuit is connected in series as an intermediate step between the phases 0 ° and 180 °, but in any case the circuit is switched every time the connection is switched. Was not enough to alleviate the shock.

Further, the applicant of the present invention has filed Japanese Patent Application No. Hei.
No. 59 discloses a first connection on / off switch in which two stator windings are connected in series delta connection, and a phase difference of a rotating magnetic field between the windings of the plurality of stators is 0 °. A second connection on / off switch for setting the phase difference of the rotating magnetic field to 120 °, wherein the phase is changed from 120 ° to 0 ° by alternately opening and closing the switches.
In this case, when the phase is switched from 120 ° to 0 °, the first and second connection open / close switches are alternately opened / closed, and one of the open / close switches is always in a closed state. The changes are 120 °, 60 °, 0 °,
By not completely opening the circuit and making the phase change in three stages, the shock associated with the phase switching has been greatly improved as compared with the one disclosed in Japanese Patent Application Laid-Open No. 54-29005, but in order to switch the switch, A control device other than an electric motor, such as a timer device for switching timing and a switching device, is required.

[0005]

According to the above-mentioned prior art, switches such as a connection changeover switch and a connection opening / closing switch for phase switching, and a control device such as a timer for controlling the switches are required. It has been difficult to commercialize the stator induction motor specifically. Therefore,
The present invention provides a large starting torque without causing a shock to the generated torque or requiring a new control device as in the related art which has been performed to improve the starting torque and its characteristics. The technical problem is to provide an inexpensive multiple-stator induction motor that can smoothly transition from start-up torque to operating torque without generating a shock, and that does not require a control device such as a timer and an open / close switch. Is what you do.

[0006]

SUMMARY OF THE INVENTION The present invention is to solve the above problems, has two rotor cores axially mounted by interposing a space or non-magnetic core portion in the same rotation shaft, the two A plurality of first rotor conductors communicating with the two rotor cores, and the first rotor conductor is provided for each of the two rotor cores;
Multiple at a position smaller than the rotor core radius where the conductor is located
A rotor formed integrally provided pieces of second rotor conductors, said two two stator core facing the respective rotor cores are arranged, fixed to the stator core Two stators for generating a rotating magnetic field by winding child windings, and the plurality of first rotor conductors in the space between the two rotor cores or in the non-magnetic core portion And a connecting member for short-circuiting the two stators with each other. One of the two stators is
Rotating magnetic field and the other generated around the rotor core facing the LES
The stator formed around the rotor core
Two stators so as to produce a predetermined phase difference with the magnetic field
A two-stator induction motor whose position is relatively shifted
did. Also, a predetermined phase difference between the two stator windings and the power supply
Realized by connection.

[0007]

According to the present invention, there are provided two rotor cores which are axially mounted on the same rotation shaft with a space or a non-magnetic core interposed therebetween.
A plurality of first rotor conductors communicating with the two rotor cores are provided, and the first rotor conductor is provided on each of the two rotor cores.
Smaller than the rotor core radius where one rotor conductor is located
A plurality of second rotor conductors are provided at positions to be integrally formed
2 a rotor that, the two two stator core facing the respective rotor cores are arranged, to rise to the rotating magnetic field by winding a stator winding in each stator core And the stator of
And a coupling member to resist shorted together a first rotary element conductor of the plurality the In space or non-magnetic core portion between the two rotor cores, of the two stators One
The rotating magnetic field generated around the rotor core where the stator faces this and the surrounding magnetic field around the rotor core where the other stator faces this
2 so as to produce a predetermined phase difference with the rotating magnetic field generated in
Stators with two stator positions shifted relative to each other
Conductive motive. A predetermined phase difference between two stator windings
And the power supply.

[0008] The first rotor conductor that communicates with the two rotor cores at the time of startup from the configuration is induced currents of different phases in each of the two rotor cores, the current of the phase difference first The rotor has a characteristic torque characteristic of an induction motor having a two- stator configuration in which a high torque is generated while a low starting current flows through a connecting member in which the rotor conductors are short-circuited with each other. On the other hand, the second rotor conductor provided for each of the two rotor cores is provided at a position smaller than the radius of the rotor core where the first rotor conductor is located. During the high secondary frequency at start-up, almost no current flows due to the skin effect. In addition, the current of the first rotor conductor flows through the connection member having the resistance short-circuited, that is, to the high resistance side. Therefore, low current and high torque start-up becomes possible by the action of the two- stator induction motor and the double-cage induction motor.

Next, when the rotation gradually increases, the secondary frequency gradually decreases and the skin effect also decreases, so that current also flows through the second rotor conductor having a small resistance value. When the rotation further increases, most of the current flows through the second rotor conductor. That since the second rotor conductors are provided independently to the two rotor cores each, the current flowing through the respective second rotor conductor of two rotor cores had relatively retardation However, unlike the first rotor conductor, there is no interference due to the phase difference, and the operating torque is the same as that of a general induction motor.

As described above, even when currents having different phases flow through the first rotor conductor, the torque characteristic of the high-resistance type is naturally switched to the torque characteristic of the low-resistance type due to the increase in the rotation speed. It is possible to provide an electric motor having a torque characteristic of an induction motor having a two- stator configuration without requiring any switching device and control device as in the prior art.
Also, no shock occurs because the phase difference is not switched,
It has become possible to provide a two- stator induction motor that can smoothly change from high-torque low-current startup to operating torque.

By the way, 2 to the first rotor conductor that communicates with the two rotor cores, a method of inducing a different current phases at each of the two rotor cores, first of all
By providing relatively shifted with respect to the other stator one of the stator of the number of stator, rotor core it
In this case, a phase difference can be provided to the current induced in the first rotor conductor communicating with the first rotor conductor . In this case, it is clear that the phase difference is different depending on the shifted angle, and the shift angle can be changed according to the required starting torque. If the load at the time of starting varies, the one stator is removed. By providing the motor in a rotatable manner, it is possible to realize a start-up torque that can cope with a load change and always realize efficient start-up.

Second, by connecting a stator winding of a specific stator, a stator winding of another stator, and a power source , a rotor core is connected.
(A) In each case, a phase difference can be provided to the current induced in the communicating second rotor conductor . In this case, the possible phase differences are 60 °, 20 °, 180 °.

Further, by reducing the first rotor conductor with respect to the cross-sectional area of the conductor of the second rotor conductor, the skin effect during the high secondary frequency at the start-up becomes remarkable, and the effect is large. Becomes

The torque characteristic of the two- stator induction motor according to the present invention generates a unique torque characteristic in which the high resistance type torque characteristic peculiar to the plural stator induction motor and the torque characteristic of the double-cage induction motor are superimposed.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. Reference numeral 1 denotes a two- stator induction motor according to the present invention, which has the following configuration.

The rotor cores 2 and 3 made of an iron core are mounted on the rotor shaft 4 at arbitrary intervals, and a space is provided between the rotor cores 2 and 3. A plurality of first rotor conductors 5 are provided on the rotor cores 2 and 3 and are connected in series, and the second rotor conductor 5 is located at a position smaller than the radius of the rotor core where the first rotor conductor 5 is located. A plurality of rotor conductors 6, 7 are provided to form an integral rotor, and both ends of the first rotor conductor 5 and the second rotor conductor 6, 7 are short-circuited rings 8, 9, 10, 11 respectively.
Is short-circuited. FIG. 2 is an enlarged cross-sectional view of the rotor core 2 showing the positions of the first and second rotor conductors. Also, in this case, the cross-sectional area of the first rotor conductor 5 is made smaller and the cross-sectional area of the second rotor conductors 6, 7 is made larger. The plurality of first rotor conductors 5 mounted on the rotor 12 are short-circuited via a connecting member 13 in the space between the rotor cores 2 and 3. In this case, the connecting material may be a nichrome wire, a carbon-containing rope, a conductive ceramic, or the like. In the case of this embodiment, as shown in FIG.
2 shows a shape in which the conductive path of FIG. Also, this shape can be any shape as long as the connection member 13 acts. FIG. 3 shows the connecting member 13 of the rotor 8 shown in FIG.
It is the expanded sectional view cut | disconnected by the part.

As is apparent from FIG. 1, bearing plates 15 and 16 are integrally mounted on both sides of the machine frame 14 by tightening nuts 17. Cooling wheels 18 and 19 are attached to both ends of the rotor 12, and both sides of the rotor shaft 4 are supported by bearings 20 and 20 fitted to bearing plates 15 and 16, so that the rotor shaft 4 is rotatable. There is.

The first stator 23 provided with the stator windings 21 and 22 and the second stator 24 are juxtaposed with the machine frame 24 at the outer side facing the rotor cores 2 and 3.

In the two- stator induction motor configured as described above , the first stator 23 and the second stator 24 are separated by the rotating magnetic field of the first stator 23 and the rotation of the second stator 24. A predetermined phase difference is generated with respect to the magnetic field. An example is shown below for this configuration.

First, a first embodiment is shown in FIG. This is a simplified diagram centering on the stators 23, 24. By providing a phase difference between the phase of the rotating magnetic field generated by the stator winding 21 of the first stator 23 and the phase of the rotating magnetic field generated by the stator winding 22 of the second stator 24, these phases are opposed to each other. The current induced in the first rotor conductor 5 communicating with each of the rotor cores 2 and 3 causes a phase difference. Therefore, the first stator 2
3 and the second stator 24 are shifted relative to each other by θ
4 to be achieved. In this case, an arbitrary phase difference can be realized by fixing the phase difference by changing the relative displacement of the stator.

Next, a second embodiment is shown in FIG. This is electrically performed in contrast to the mechanical displacement of the fixed position of the stator in the first embodiment. In other words, this is achieved by connecting the stator winding 21 of the first stator 23, the stator winding 22 of the second stator 24, and the power supply. The phase difference that can be realized in this case is generally an electrical angle θ = 60 °, 120 °,
There are three types of 180 °. FIG. 5 is also possible by a series star connection, a parallel star connection, and a parallel delta connection.

By the way, when the phase difference is provided as described above,
The second rotor conductors 6, 7 are composed of a rotor core 2 and a rotor core 3.
Are short-circuited by the short-circuit rings 10 and 11 in each of the cases, there is no influence by providing the phase difference by any of the methods of the above-described embodiments, and even if there is a relative phase difference, the two This is the same as a state in which a general single stator induction motor is directly connected with a rotor shaft.

The operation of the above configuration will be described. The operation of the induction motor having a plurality of stators when the above-described phase difference is provided is described in detail in Japanese Patent Publication No. 27920/1990 by the present applicant, and is omitted here.

As described above, when the rotor core 2 and the rotor core 3 are started up in a configuration in which the respective currents induced in the first rotor conductors 5 connected in series are provided with a relative phase difference, In the first rotor conductor 5, a current having a different phase is induced in each of the rotor cores 2 and 3, and a current having a phase difference is generated by the first rotor conductor 5. Flows through the connecting member 13 in which resistance is short-circuited to each other, and a torque characteristic peculiar to a plurality of stator induction motors generating a high torque while having a low starting current is obtained. On the other hand, the second rotor conductors 6, 7 provided respectively for the rotor cores 2, 3
Is provided at a position smaller than the radius of the rotor core where the first rotor conductor 5 is located, so that the current is increased by the skin effect while the secondary frequency at the time of startup is high as in a double-cage rotor. It is hard to flow. That is, most of the current flows through the first rotor conductor 5 having a small conductor cross-sectional area, the current having a phase difference flows through the connection member 13 having a resistance short circuit, and the secondary side has a high resistance value, resulting in a high-resistance rotor. . Therefore, the low-current, high-torque start-up becomes possible by the action of the multiple stator induction motor and the double-cage induction motor.

Next, when the rotation gradually increases, the secondary frequency gradually decreases and the skin effect decreases, so that a current is induced also in the second rotor conductors 6 and 7 by the induction action with the rotating magnetic field. Become. When the rotation further increases, the skin effect disappears and the current flows to the side having the smaller resistance value. That is, the current induced by the rotating magnetic field of the stators 23 and 24 and the induction action between the rotor conductors flows through the connecting member 13 in which the phase difference of the current is short-circuited on the first rotor conductor 5 side, while Since there is no connecting material on the rotor conductors 6 and 7 side and the conductors are provided independently of the rotor cores 2 and 3, the current flowing through the second rotor conductors 6 and 7 is relatively out of phase with each other. Nevertheless, since there is no mutual interference and the conductor cross-section is larger and the resistance is lower than that of the first rotor conductor, most of the current flows in the second rotor conductor 6,
7 will flow. Therefore, at the rated rotation, the operating torque becomes the same as that of a general induction motor. FIG. 6 shows the torque characteristics at this time.

As described above, it is possible to operate as a high-resistance type induction motor at the time of starting and as a low-resistance type induction motor at the time of operation without the need for parts and devices other than the motor, and the switching thereof can be performed automatically. A simple induction motor.

[0027]

As described above, even when currents having different phases flow through the first rotor conductor, the torque characteristic of the high-resistance type naturally changes from the torque characteristic of the high-resistance type to the low-resistance type due to the increase in the rotation speed. Thus, it is possible to provide a motor having the torque characteristics of a multiple stator induction motor without requiring any switching device and control device. In addition, since the phase difference is not changed, no shock occurs and a smooth start is possible. As a result, nothing other than the induction motor is required, and a high-torque start-up is possible. This has a great effect in a field requiring a start-up improved shockless induction motor.

[Brief description of the drawings]

FIG. 1 is a side sectional view of a two- stator induction motor of the present invention.

FIG. 2 is an enlarged front sectional view of the rotor core of FIG. 1;

FIG. 3 is an enlarged front sectional view of the rotor viewed from the connecting member of FIG. 1;

FIG. 4 is a simplified diagram of a stator for providing a phase difference.

FIG. 5 is a connection diagram between a stator winding having a phase difference and a power supply.

FIG. 6 shows torque characteristics of a two- stator induction motor according to the present invention.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 2 stator induction motor 2 rotor core 3 rotor core 4 rotor shaft 5 first rotor conductor 6 second rotor conductor 7 second rotor conductor 8 short circuit ring 9 short circuit ring 10 short circuit ring 11 short circuit Ring 12 Rotor 13 Connecting material 14 Machine frame 15 Bearing plate 16 Bearing plate 17 Nut 18 Impeller 19 Impeller 20 Bearing 21 Stator winding 22 Stator winding 23 First stator 24 Second stator

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-157291 (JP, A) JP-A-60-7667 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 16/00-16/04 H02K 17/16-17/20

Claims (3)

(57) [Claims] 1. A first rotor conductor having two rotor cores axially attached to the same rotation shaft with a space or a non-magnetic material core interposed therebetween, and a first rotor conductor communicating with the two rotor cores is provided. A plurality of first rotors are provided for each of the two rotor cores.
Multiple at a position smaller than the rotor core radius where the conductor is located
A rotor formed integrally provided pieces of second rotor conductors, said two two stator core facing the respective rotor cores are arranged, fixed to the stator core Two stators for generating a rotating magnetic field by winding child windings, and the plurality of first rotor conductors in the space between the two rotor cores or in the non-magnetic core portion And a connecting member for short-circuiting the two stators with each other. One of the two stators is
Rotating magnetic field and the other generated around the rotor core facing the LES
The stator formed around the rotor core
Two stators so as to produce a predetermined phase difference with the magnetic field
It is characterized by being relatively displaced in position
2 stator induction motor. 2. A first rotor conductor having two rotor cores axially mounted on the same rotation shaft with a space or a non-magnetic core interposed therebetween, and a first rotor conductor communicating with the two rotor cores. A plurality of the second rotor conductors are provided on each of the two rotor cores at a position smaller than a radius of the rotor core where the first rotor conductor is located. The formed rotor and two stator cores are arranged in parallel with each other to face each of the two rotor cores. A stator winding is wound around each stator core to generate a rotating magnetic field. A plurality of stators, and a connecting member for mutually resistance-short-circuiting the plurality of first rotor conductors in the space between the two rotor cores or in the nonmagnetic core portion. One of the stators has a rotating magnetic field generated around the rotor core facing the other, and the other stator has a rotating magnetic field corresponding to the rotating magnetic field. 2 stator induction motor characterized by comprising by connecting the two stator windings and the power supply so as to produce a predetermined phase difference between the rotating magnetic fields generated around the rotor core. Wherein the sectional area of the first rotor conductor second
3. The two- stator induction motor according to claim 1 , wherein the cross-sectional area of the rotor conductor is reduced.