JPH02311152A - Voltage phase shifter for multiple-stator induction motor - Google Patents

Abstract

PURPOSE:To generate a high torque from a speed shifting or low speed to a high speed rotating range by composing a voltage phase shifter of a centrifugal switch. CONSTITUTION:A centrifugal switch provided at a rotor shaft is composed of two sets of switches. C sides of S1 and S2 are connected to the common terminal of one switch, B side of S4 is connected to the B contact side terminal, and A side of S1 is connected to the A contact side terminal. C sides of common terminals S13', S24', of the other switch are connected, B side of S24' is connected to the B contact side terminal, and A side of S13' is connected to the A contact terminal. With the above connections, in case of series Y connection, i.e., when the rotation of the rotor is zero or a low speed by the opening/closing of S1, S4, S13', S14' and the operation of the switch upon rotation of the rotor, the phase difference of the stator windings 22, 23 becomes 180 deg.. The phase difference from the arbitrary speed to a rated speed becomes zero. Thus, a high torque can be generated from a speed shifting or a low speed to a high speed rotation.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an induction motor, and more specifically, a single rotor, a plurality of stators, and any one of the plurality of stators. a voltage phase shifter that creates a phase difference between a voltage induced in a rotor conductor portion facing one stator and a voltage induced in a corresponding rotor conductor portion facing the other stator; The present invention relates to a so-called multi-stator induction motor having a rotor whose rotational speed and generated torque can be varied by adjusting a voltage phase shifter.

[Conventional technology]

Conventionally, star-delta starting, reactor starting, starting compensator starting, etc. are known as means for controlling the starting current when starting a squirrel cage blade conductive motor that is commonly used. Although it was possible to control the starting current, it was not possible to improve the starting torque.

Furthermore, in a wound wire electric motor, although it is possible to improve the starting torque by changing the resistance value of the secondary resistor, it is necessary to use brushes and a stop ring, making maintenance difficult.

Here, the present applicant has disclosed in Japanese Patent Application Laid-open No. 62-260590 that the speed control range can be set in a wide range to any desired speed, it can be started with any torque, and the maximum rotational speed from the starting point can be set to any desired speed. This paper discloses an induction motor with a multiple stator configuration that has excellent torque characteristics and efficiency over the entire speed range.

[Problem to be solved by the invention]

The multi-stator induction motor in the prior art of the present applicant or the prior application has a multi-stator induction motor coaxially with an integral rotor having a plurality of rotor cores, and a plurality of stator cores facing each of the rotor cores. stators, and a voltage induced in a rotor conductor facing one stator and a voltage induced in a rotor conductor facing the other stator is applied to at least one stator among the plurality of stators. The device is equipped with a voltage phase shifter that creates a phase difference between the induced voltage and the voltage phase shifter that rotates at least one stator out of a plurality of stators concentrically with the rotor axis. It was designed to be mounted on a rotating stator, and to switch between stator winding connections and power supply.

However, such a voltage phase shifter is equipped with a sensor that detects the rotation speed, and the signal from the sensor is used to switch, for example, the drive source that rotates the rotary stator, the connection of the stator windings, and the power supply. This used to be an expensive voltage phase shifting device due to the need for a control device and the like to control the device.

Therefore, by providing a phase shift in the rotating magnetic field between the two stators, we can diversify the torque and improve the voltage transfer of a multi-stator induction motor that can generate high torque from shifting or starting to the rated rotation range. The technical challenge is to improve the conventional drawbacks of phase devices and make a significant contribution to all fields that require expanded applications and high-torque electric motors.

[For production]

According to the present invention, the voltage phase shifter is configured with a centrifugal switch that is provided concentrically with the rotating shaft and operates at an arbitrary rotational speed, so there is no need for an expensive sensor or a control device for it.

In detail, the wiring of multiple stators is connected with a phase difference that generates high torque when the rotation speed of the rotor shaft is zero or low, and high torque is generated in the rated rotation speed range above the arbitrary rotation speed. Since the voltage phase shifter is configured using the centrifugal switch, the centrifugal switch is a mechanical device and the stator windings are connected to each other to switch to a connection with zero phase difference. We were able to.

In addition, a device that operates a voltage phase shifter using a signal from a centrifugal switch installed concentrically with the rotating shaft does not require a sensor amplification device using a sensor or a control device that receives the signal, as in the prior art. First, it is possible with simple sequence control.

Specifically, the centrifugal switch operates at an arbitrary rotation speed due to the rotation of the rotary shaft, and the ON/OFF signal of this centrifugal switch is used as an input signal to an arbitrary opening/closing means such as an electromagnetic switch, and the input causes the rotation of the rotor shaft. A centrifugal switch is created by providing an opening/closing means to switch between a connection with a phase difference that generates high torque when the number of rotations is zero or at low speed, and a connection with a phase difference of zero that generates high torque at a rated rotation speed higher than the desired rotation speed. can be indirectly used as a simple sensor.

By the way, some single-rotor and single-stator induction motors are equipped with a centrifugal switch on the rotating shaft. Although it is a centrifugal switch, the centrifugal switch according to the present invention provides a phase difference in order to shift with a high constant torque from the start to the rated rotation, and its purpose is different from that for simply starting. ing.

〔Example〕

The configuration of the variable speed induction motor according to the present invention will be explained below with reference to FIGS. 1 to 3.

A rotor portion 2.3 consisting of an iron core is mounted on a rotor shaft 4 at an arbitrary interval, and the rotor portion is formed by stacking steel plates with a plurality of conductor holes to form a rotor core. Applying an insulating material to the rotor core and casting aluminum to form a plurality of conductors 5 in the conductor holes, short circuit rings 6 and 7 at one end thereof, and an end portion 51 for the plurality of conductors at the other side. did.

Further, a conductor 55 is connected in a continuous manner between the rotor portions 2.3, thereby integrally forming the rotor portions 2.3. Rotor part 2
．． The conductor 55 connected in a continuous manner between 3 and 3 is connected to the resistive material r...
・For example, short-circuit connections are made through aluminum, copper-nickel alloy, nickel-chromium alloy, iron-chromium alloy, stainless steel, etc. The conductor 55 between this rotor part 2.3
The space formed by the resistive material and its surroundings may be left as is or may be formed from a non-magnetic material.

Moreover, the resistance material r can be formed in the cooling effecting body 13 as a cooling agitator having an arbitrary shape. In this way, the rotor parts 2, 3, the conductor 55 and the resistive material r form the integral rotor 8.
form.

Also, in the rotor part 2.3, both sides 10.11 of the rotor 8 are provided.
A plurality of ventilation cylinders 12... are provided which communicate with each other.

A stator 25.31 respectively faces the rotor part 2.3.
are provided concentrically with the rotor portions 2, 3, and the stator 25.
31, a plurality of ventilation cylinders 60 connected to both sides of the stator;
will be established.

Both ends of the rotor shaft 4 are supported by bearings 21 and 21 fitted in bearing discs 15 and 16, and the bearing discs 15 and 16 are integrally assembled to both sides of the cylindrical machine frame 14 with bolts 17. , the rotor 4 is rotatable.

As shown in FIGS. 1 and 2, a winding 22.23 is disposed concentrically with respect to the rotor portion 2.3 on its outer side as previously described.
The first stator 31 and the second stator 25 which have been subjected to the above-described process are arranged side by side facing each other. At this time, as is clear from Fig. 1, the stator 2
The coil ends of the windings 22 and 23 protruding in the four directions of the rotation axis of 5.31 are provided so as to spread outward from the center of the stator 25 and 31 to the outside of the stator circumference, creating resistance between the plurality of rotor cores. Rotating shaft 4 of the variable speed induction motor according to the present invention provided with a material
To make it possible to configure the length of a direction to be short.

The first stator 31 and the second stator 25 are fixed to the inner wall surface of the machine frame 14 to form fixed stators.

A small motor 72 with a fan 71 attached to the shaft is connected to the suction section 74.
A cooling device 73 is fixedly installed in a fan case 70 having an air exhaust section 74B, and a cooling device 73 is fixedly installed in the machine frame 14.
I will contact you within 4 days.

A plurality of openings 39 are opened, and the plurality of openings 39 are formed into an arbitrary number of ventilation ports 65 and ventilation ports 66.
communicates with the suction lower 4A.

A plurality of ventilation holes 40... are bored in the bearing discs 15, 16.

Next, FIG. 3 shows a rotor portion 2 including a resistive material r and a conductor 55.
．． It is a side sectional view between 3 and 3. Ends 51 of rotor parts 2, 3
A plurality of conductors 55 formed by a conductor 56 and a conductor 57 having a curved portion are fixed in a continuous manner.

A resistive material r is placed around the conductor 55 fixed in a continuous manner.
Connect and weld. At this time, the resistance material r may be formed integrally with the conductor 55 by die-casting. Although the conductors 56 and 57 having curved portions were shown earlier, the curved portion may be omitted in some cases, and in that case, the conductor 56 and the conductor 57 may be aligned with each other with an arbitrary interval.

Incidentally, although the example in which the conductor 55 is formed by the conductor 56 and the conductor 57 has been shown, the conductor 55 is formed by the conductor 56 and the conductor 5 having a curved part.
7 may be provided symmetrically and the combined portions may be fixed by welding means such as spot welding, or may be integrally formed by die casting as described above. At this time, the conductor 56.5
The cross-sectional shape of 7 can be arbitrarily selected.

In the multi-stator induction motor described above, when a phase difference is provided between the first stator 31 and the second stator 25, a phase shift occurs in the rotating magnetic field generated between the rotor and the stator, and the rotation By increasing or decreasing the voltage induced in the child conductor, the rotation speed of the rotor can be changed arbitrarily. When the rotary stator 31 is further rotated, the conductors 55 and 5 installed in communication between the rotors 2 and 3 are short-circuited and connected by the resistive material r. A current flows through r due to the phase difference, and the resistance of the rotor conductor 5 increases, making it possible to generate a large torque.

Next, the connection of the windings 22 and 23 wound around the first stator and the second stator will be explained based on FIGS. 4 to 7 (details will be described later).

However, in this example, the phase difference is set to 2, 0 and 180°.
We will discuss two cases.

At least the following four wiring methods are conceivable for the present invention. So-called series △ connection, series Y connection, parallel △ connection,
It is a parallel Y connection. Wires are connected to the terminals of each winding like △ and Y, and the connections are equipped with changeover switch groups cs, s,', s, □ to create a phase difference.
.

s+v'l 8+4' + 324' + SN
4*sa, s4') are present (Figs. 4 to 7). By switching this switch, the first
This results in a phase difference of θ° and ■80° between the voltages induced in the rotor conductors facing the stator and the second stator, respectively.

Generally, in symmetrical three-phase AC, the instantaneous value of electromotive force e
I, e b, e c are as follows.

ex=EI! 1 Sinωj, eb = Em Sin
(ωt −2π/3) ea = Em Sin ((IJI −4yr/3)
The vector diagram of Ex, Eb, and Ec is shown in Figure 14, and each electromotive force has a phase difference of 2π/3. By connecting the windings of the stator and second stator as shown in Figures 4 to 7 and changing each connection from (1) to (2), the relative O', 180 This results in a phase difference of .

For example, looking at the Y connection in the 9th row, the power supply U,
V, W to winding 23, terminals UF, VF.

WF, and the other terminal xF of the winding 23.

Connect YF and ZF to terminals UM, VM, and W of winding 22, respectively.
M, and the other terminals of the winding 22 XM, YM, Z
M is shorted (connection (1)).

At that time, no phase difference occurs in the windings 22 and 23. However, the terminals UM, VM, WM and XM, YM of winding 22
,, If the terminals of ZM are connected as shown in (2), the vector diagram will be of opposite phase, so it will be equivalent to a phase difference of π from the vector diagram of connection (1).

In this way, by switching the connections, the phase difference between the voltages induced in the conductors of the rotor facing the winding 23 and the winding 22, that is, the first stator and the second stator, changes.

This connection switching is performed by switching the switch groups shown in FIGS. 4 to 7 described above. Here, regarding the other connections, that is, Figures 8, 10, and 11, the voltage vector diagram when changing the connection from (1) to 2) is almost the same, so the explanation will be omitted. .

Table 1 below shows the open/close states of the switches for producing the respective phase differences in each connection method.

A first embodiment in which the present invention is applied to a multi-stator induction motor having the configuration shown in Table 1 or above will be shown below. First, the configuration of the centrifugal switch 80 is shown in FIGS. 1 and 12.

The centrifugal switch 80 provided on the rotor shaft 4 includes arms 82 provided on the left and right sides of the rotary shaft 4 on a fixed plate 81 fixed to the rotary shaft 4, and a ring 8 fitted so as to be slidable on the rotary shaft.
Arms 84 provided on the left and right sides of the rotating shaft 3 are engaged with the rotating shaft 4 on the left and right sides of the rotating shaft 4, and elastic bodies 85 are stretched over the engaging portions. A movable disc 86 is provided in contact with the end face of the ring 84 so as to be slidable on the rotating shaft 4, and the movable disc 86 is in contact with a switch 90.95.

The common terminal 89 (93) of the switch 90 (95), which the movable disc 86 comes into contact with, switches its contact between the A contact side 87 (92) and the B contact side 88 (91) by sliding the movable disc 86. . Also each switch 90.95
And the common terminal 89 is formed in a double-connected type. Note that the common terminals 89 and 93 are biased toward the B contact side.

The action of this centrifugal switch will be explained. When the rotor 8 is stopped, the arm 84 is urged toward the rotor shaft 4 side by the elastic body 85 as shown in the figure, and the ring 83 connects the movable disk 86 to the common terminals 89 and 93 of the switches 90 and 95 to the A contact 87.
．． Abut against the 92 side. However, when the rotor 8 starts, the arms 82 and 84 gradually expand outward from the rotating shaft 4 due to centrifugal force, and when the tension of the elastic body 85 is finally exceeded, the outward expansion of the arms 82 and 84 causes the ring 83 to expand. is moved toward the fixed plate 81 side, and accordingly,
Combined with the repulsive force of the common terminal 89.93 biased toward the B contact 88.91 side of the switch 90.95, the movable disc 86
moves toward the fixed plate 81 together with the ring 83. By moving the ring 83 and the movable disc 86 left and right, the common terminal 89 (93) moves to the A contact side 87 (92) at an arbitrary rotation speed.
or to the B contact side 88 (91).

Next, the connections between the centrifugal switch 80 and each of the above-mentioned connections will be shown. However, only the connection with the series Y connection will be shown here, and the connections with other connections will be omitted since they are just a summary.

In Fig. 5, when the phase difference of the windings 22 and 23 is zero in the series Y connection, from Table 1, sl and Stl' are closed, and SJ,
S24" is open. Also, when the phase difference is 180°, from Table 1, SJ, 524- is closed and s, 5t3- is open. From this, common terminal 8 of switch 90'
9, the B side of the SJ is connected to the B contact side 87 of the switch 90, and the A side of the SJ is connected to the A contact side 88 of the switch 90. Also, S is connected to the common terminal 93 of the switch 95.
Connect the C sides of t3' and 824', connect the B side of S24' to the B contact side 92 of the switch 95, and connect the A side of 5tl- to the A contact 91 side.

When connected as above, as mentioned earlier, series Y connection,
In other words, due to the opening and closing of Sl, SJ, 5tl-, 524- and the action of the centrifugal switch 80 as the rotor 8 rotates, the stator windings 22, 23 when the rotor 8 rotates at zero or low speed.
The phase difference is 180' (SJ, 524- is closed) from the initial rotation speed to the rated rotation speed, the phase difference is zero (SJ, So-
(closed) and can be realized at low cost due to the simple action of the centrifugal switch 80.

In this embodiment, a voltage phase shifting device is formed by the centrifugal switch 80 and the arbitrary connection method (series-parallel Y, Δ connection).

Next, the embodiment shown in FIG. 2 will be described. The diagram shown in FIG. 13 is a simple sequence diagram used in this embodiment.

Three-speed electromagnetic switch with A contact and B contact 101.10
2 are actuated by electromagnetic coils 103 and 104, respectively. The electromagnetic coils 103 and 104 are connected in parallel and in series with the centrifugal switch 80. One terminal a of the centrifugal switch 80 and the other terminals of the electromagnetic coils 103 and 104 are connected to a control power source 105. The simplest switch circuit 100 suitable for this embodiment is formed from the above configuration. This switch circuit 100 includes a centrifugal switch 80
That is, when the rotor 80 is closed, the electromagnetic coils 103 and 104 are activated, and the electromagnetic switch 1
01 and 102, respectively, when the A side of the switch is closed and the B side is open. When the rotation of the rotor 8 is above the arbitrary rotation speed or the rated rotation speed, the centrifugal switch 80 is opened and the electromagnetic coil 103.10
4 is stopped, and the electromagnetic switches 101 and 102 operate such that the B side is closed and the A side is opened. Through this operation, the opening/closing operation performed by the centrifugal switch 80 of the first embodiment is replaced by the electromagnetic switches 101 and 102,
The centrifugal switch 80 of the second embodiment serves as a signal output element corresponding to the rotation speed of the rotor 8.

With this configuration, the structure of the centrifugal switch 80 is simplified, and the centrifugal switch 80 not only functions as a signal output element, but also does not function as a terminal for directly changing the connection as in Embodiment 1. No maintenance required.

In this embodiment, the centrifugal switch 80, the arbitrary connection method (series-parallel Y, Δ connection), and the switch circuit 1
00 to form a voltage phase shifter.

〔effect〕

According to the present invention, with the above configuration, when a multi-stator induction motor generates high constant torque from low speed rotation to rated rotation, the phase difference between the stators can be changed using a simple centrifugal switch or a centrifugal switch. This can be realized using a simple sequence circuit using signal elements.

In other words, there is no need for an element that detects the rotation speed of the rotor, an amplifier for this element, and a control circuit for receiving signals from the amplifier. There is no need for a bearing device, a drive device, etc. to form the stator, or a control device for that purpose.Therefore, by creating a phase shift in the rotating magnetic field between the two stators, it is possible to diversify the torque. The use of multi-stator induction motors that can generate high torque from low speeds to the rated rotation range has expanded, making it possible to greatly contribute to all fields that require high-torque motors.

[Brief explanation of the drawing]

Fig. 1 shows a variable speed induction motor according to the present invention, and Fig. 2 shows a variable speed induction motor according to the present invention.
3 is a detailed view of the portion between the rotor cores of the variable speed induction motor according to the present invention, and FIGS. 4 to 7 are connection diagrams of the stator windings. Figures 8 to 11 are diagrams showing a wiring method that produces multiple phase differences in the stator, Figure 12 is a diagram showing the centrifugal switch of the first embodiment, and Figure 13 is a diagram showing the second embodiment. , FIG. 14 is a vector diagram showing the instantaneous value of the electromotive force of three-phase symmetrical alternating current. 1... variable speed induction motor, 2.3... rotor part,
4... Rotor shaft, 5... Rotor conductor, 6, 7...
Short-circuit ring, 8...Rotor, 10.11...Both sides, 1
2... Passage body, 13... Cooling body, 14... Machine frame, 15° 16... Bearing board, 17... Bolt, 21
... bearing, 22.23 ... winding, 25 ... second stator, 29 ... drive device, 30 ... rotation mechanism, 31
...first stator, opening, 40...ventilation port, 51.
...End portion, 55...Conductor having a curved portion, 56...
Conductor, 57... Conductor, 60... Ventilation shell, 65...
Air outlet, 66...Exhaust port, 70...Fan case,
71...Centrifugal fan, 72...Motor, 73...
・Cooling device, 74A...Suction port, 74B...Exhaust port, 80...Centrifugal switch, 81...Fixing plate, 82...
...Arm, 83...Ring, 84...Arm, 8
5... Elastic body, 86... Movable disc, 87... A contact side, 88... B contact side, 89... Common terminal, 9
0...Switch, 91...B contact side, 92...A
Contact side, 93... Common terminal, 95... Switch,
100... Switch circuit, 101... Electromagnetic switch,
102... Electromagnetic switch, 103... Electromagnetic coil, 1
04... Electromagnetic coil, 105... Control power supply, r.
...Resistance material.

Claims (2)

[Claims] (1) A plurality of rotor conductors are installed in a continuous manner on a plurality of rotor cores that are mounted on the same rotating shaft at regular intervals, and the rotor conductors are connected to the plurality of rotor cores. A plurality of stators are formed, each having an integral rotor short-circuited between child cores by a resistive material, and stator cores facing each rotor core coaxially with the rotor,
At least one stator among the plurality of stators,
The voltage induced in the rotor conductor facing one stator,
In a multi-stator induction motor provided with a voltage phase shift device that generates a phase difference between the voltage induced in a rotor conductor facing the other stator, the voltage phase shift device is configured to A voltage phase shifting device for a multiple stator induction motor, comprising an actuated centrifugal switch. (2) A plurality of rotor conductors are installed in a continuous manner on a plurality of rotor cores that are mounted on the same rotating shaft at regular intervals, and the rotor conductor is connected to the plurality of rotor cores, and A plurality of stators are formed, each having an integral rotor short-circuited between child cores by a resistive material, and stator cores facing each rotor core coaxially with the rotor,
At least one stator among the plurality of stators,
The voltage induced in the rotor conductor facing one stator,
In a multi-stator induction motor equipped with a voltage phase shifter that creates a phase difference between the voltage induced in a rotor conductor facing the other stator, a centrifugal switch that operates according to the rotational speed of the rotating shaft is rotated. A voltage phase shifting device for a multi-stator induction motor, characterized in that the voltage phase shifting device is provided concentrically with a shaft and is activated by a signal from the centrifugal switch.