JP2762100B2 - Electric motor device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor device suitable for high-speed positioning, and more specifically, it can be operated as an induction motor and can also be operated as a step motor. The present invention relates to an electric motor device.

[Problems to be solved by conventional technology and invention]

 The following performance is required for the positioning motor system.

(1) High-speed operation is possible.

(2) Control operation is possible.

(3) Able to drive at low speed and smooth.

(4) The restraining torque must be large.

The step motor conventionally used can perform positioning with a simple control circuit configuration, and has excellent performance in the above items (3) and (4). High speed operation is not always enough.

Further, the induction motor is structurally simple and robust as an electric motor, and can perform an efficient operation from a medium speed to a high speed operation. However, (2)-(4)
The term does not have that ability.

A DC servo motor system using a DC motor and an AC servo motor system using a synchronous motor have all of the above-mentioned performances (1) to (4). A rotation speed sensor and a position sensor are required.

Therefore, an object of the present invention is to provide an electric motor device capable of obtaining a high-speed rotation state and a low-speed rotation state with a simple configuration.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a plurality of grooves extending from respective central portions of a pair of main surfaces arranged to be orthogonal to a central axis toward respective outer peripheral portions. A rotor core having a plurality of conductors or windings formed from the center of one main surface of the rotor core to the center of the other main surface and inserted into the groove; Means for short-circuiting the plurality of conductors or windings, and a first stator main surface facing one main surface of the rotor core, and the center of the first stator main surface is A plurality of protrusions and grooves are disposed so as to coincide with the center of the rotor core and extend from the center of the first stator main surface toward the outer peripheral edge, and the number of protrusions and grooves is A first fixation determined to be different from the number of grooves on one main surface of the rotor core A magnetic core, and a second stator main surface facing the other main surface of the rotor core, and arranged such that the center of the second stator main surface coincides with the center of the rotor core. And the second stator has the same number of protrusions and grooves as the number of protrusions and grooves of the first stator core extending from the center of the second stator main surface toward the outer peripheral edge. A second magnetic field acting on the rotor via an opposing gap between a stator core and a first main surface of the first stator core and one main surface of the rotor core. A first stator winding disposed on the first stator main surface, and an opposing gap between the second stator main surface of the second stator core and the other main surface of the rotor core A second stator winding disposed on the second stator main surface so that a rotating magnetic field acts on the rotor via the first and second stator windings; Those relating to the motor device consisting of a drive circuit which is capable of selectively applying the anti-phase voltage with each other it is possible to selectively apply the voltage of the same phase in the stator windings.

(Operation)

In the present invention, when an in-phase voltage is supplied to the first and second stator windings, the stator winding rotates as an induction motor. on the other hand,
When voltages of opposite phases are supplied to the first and second stator windings,
No induced voltage is generated in the conductor of the rotor. However, since the number of protrusions (teeth) of the rotor is different from the number of protrusions (teeth) of the stator, the motor operates as a reluctance step motor.

〔Example〕

Next, an electric motor device according to an embodiment of the present invention will be described with reference to FIGS.

As shown in FIG. 1, this motor device has one rotor 1 and first and second stators 2 and 3. Rotor 1
Is fixed to the rotating shaft 4. The rotating shaft 4 is provided with a bearing 5
It is supported by. The first stator 2 is arranged opposite one main surface of the rotor 1, and the second stator 3 is arranged opposite the other main surface of the rotor 1.

The rotor 1 comprises a rotor core 6 and a conductor 7, as shown in FIGS. The rotor core 6 has a center hole 8 and a large number of grooves 9 extending radially from the vicinity of the center hole 8 toward the outer peripheral edge. The groove 9 is formed on both one main surface 10 and the other main surface 11 of the rotor core 6. Groove 9
The radial projections 12 between them have a function corresponding to the teeth of a step motor, and are determined to be, for example, 12n + 1 (where n is an integer) in a three-phase four-pole configuration.

The conductor 7 is formed in a U-shape, and is disposed so as to extend from one main surface 10 to the other main surface 11. One end and the other end of the plurality of conductors 7 are mutually connected by short-circuit rings 13 and 14.
In short, the conductor 7 has the same principle as that of the cage of the induction motor.

The first stator 2 includes a first stator core 15 and a first stator winding 16. As shown in principle in FIGS. 4 and 5, the first stator core 15 has a large number of grooves 18 extending radially from the vicinity of the center hole 17 toward the outer peripheral edge.
The projections 18 are provided between the projections 18. This projection 19 has the same function as the teeth of the step motor,
In the case of three phases and four poles, the number is determined to be 12n, which is different from the number of protrusions 12 of the rotor 1. The first stator winding 16 is disposed on the main surface 20 of the first stator 2 using the protrusion 19. FIG. 6 shows U, V, and W phase windings U _{1 in a} three-phase four-pole configuration.
_{~U 4, V 1 ~V 4,} W described manner showing the arrangement of ₁ to _W-4. FIG. 7 shows in principle how to wind a winding 16 of four slots per pole and one.

The second stator 3 includes a magnetic core 21 and windings (not shown in FIG. 1), and has the same configuration as the first stator 2. That is, the first stator main surface 22 of the second stator 3
The same grooves and protrusions as those of the stator main surface 20 are provided, and the main surface 22 faces the main surface 11 of the rotor 1. Also, the first
The arrangement angular positions of the windings of the second stators 2 and 3 are exactly the same. The bearing 5 includes first and second stator cores 1.
5, 21 are arranged in the central holes 17, 23.

FIG. 8 shows three-phase windings 2 of the first and second stators 2 and 3 respectively.
The drive circuit for U, 2V, 2W, 3U, 3V, 3W is shown. The drive circuit includes a DC power supply 30, an inverter 31, and a switching circuit 32. The inverter 31 includes six transistors Q _{1 to} Q ₆ and six diodes D _{1 to} D _{6 connected} to a pair of DC power supply run-ins 30a and 30b.
This is a three-phase bridge inverter connected between the bridges.
The first, second and third phase output lines 3 of this inverter 31
The reference numerals 3, 34 and 35 are connected to the second stator windings 3U, 3V and 3W without using a switch. The second stator windings 3U, 3V, 3W are Y-connected, the midpoint is selectively connected to one of the DC power supply lines 30a through switch S _8.

The first stator winding 2U, 2V, 2W-end are switch S _1,
The Y-connection forming circuit 36 for the induction motor through the contacts a of S ₂ and S ₃
Is selectively connected to, are selectively connected to the inverter output line 33, 34 and 35 via the contact b of the switch _{S 1, S 2, S 3} . The first stator winding 2U, 2V, and the other end of 2W is selectively connected to a switch S _4, S _5, step motor Y-connection forming circuit 37 through the contact a of S ₆ ,
Switches S ₄ , S ₅ , and S ₆ are selectively connected to inverter output lines 33, 34, and 35 via contact points b. Step motor Y-connection forming circuit 37 is selectively connected to a DC power supply line 30a through a switch S _7.

(Induction motor operation)

When operating as an induction motor in order to obtain a high-speed rotation state, put the switch S ₁ to S ₆ of FIG. 8 to the contact a,
Operate to turn off the switch S _7, S _8. In addition, the switch S ₁ ~
S ₈ is configured to work together. Thereby, the ninth
The circuit shown in FIG. First and second stator windings 2
Since U, 2V, 2W, 3U, 3V, and 3W are driven in phase, FIG. 10 schematically shows a momentary magnetic pole of each of the stators 2 and 3. First and second stator windings 2U, 2V, 2W, 3U, 3V, 3W
Are driven in the same phase, so that the same magnetic pole is generated at the same angular position. Since three-phase alternating current is supplied to each winding, the first
The second stators 2 and 3 generate a rotating magnetic field while maintaining the magnetic pole arrangement as shown in FIG. The magnetic flux based on the first rotor 2 is linked to the conductor 7 of the rotor 1 along a path indicated by a chain line 38, and an induced electromotive force is generated in the conductor 7 according to Fleming's right-hand rule, so that a current flows. When the current-carrying conductor 7 cuts off the magnetic flux, the rotor 1 rotates according to Fleming's left-hand rule.

The magnetic flux based on the second stator 3 crosses the conductor 7 of the stator 1 along a path indicated by a chain line 39. As a result, the direction of the current generated in the conductor 7 is the same as that in the case of the first stator 2, so that a torque is generated in the rotor 1 in the same direction as in the case of the first stator 2. Eventually, the rotor 1 rotates on the same principle as the induction motor.

[Step motor operation]

In the case of the step motor operation, the switch S ₁ shown in FIG.
Respectively put into contact b of to S _8. In addition, the inverter 31
Off control of the upper three transistors Q ₁ , Q ₃ , Q ₅
The lower three transistors Q ₂ , Q ₄ and Q ₆ are pulse width modulated so as to generate a sine wave. As is clear from FIG. 11 showing the circuit when the stepping motor operates, the first stator windings 2U, 2V, and 2W are out of phase (about 180 degrees) with the second stator windings 3U, 3V, and 3W. Current). When the transistors Q ₁ , Q ₃ , and Q ₅ of the inverter 31 are turned off and only the pulse width modulation control of the transistors Q ₂ , Q ₄ , and Q ₆ is performed, the currents I _U and I with DC bias are applied as shown in FIG. _V, it is possible to flow the I _W. Thereby, the peak value of the magnetomotive force of the rotating magnetic field increases, and the reluctance force and the rotating force increase.

FIG. 13 schematically shows an instantaneous state of the magnetic poles of the first and second stators 2 and 3 during the step motor operation. The first stator 2 has a magnetic pole in a direction opposite to that of the second stator 3. As a result, the magnetic flux of the two stators 2 and 3 reciprocates between the two stators 2 and 3 and penetrates the rotor 1 as shown by a chain line 40, and is linked to the conductor 7 of the rotor 1. do not do. In other words, the voltage and current induced in the conductor 7 cancel each other based on the magnetic fluxes of the first and second rotors 2 and 3, and no rotational torque is generated as the induction motor. However, since the rotor core 6 has the protrusion 12 and the stator core 15 opposite thereto also has the protrusion 19, the rotor 2 rotates so that reluctance (magnetic resistance) is minimized.
That is, the rotor 1 rotates according to the principle of the reluctance motor following the movement of the rotating magnetic field generated by the first and second stators 2 and 3. At this time, if the difference between the number of the protruding portions 19 of the stators 2 and 3 and the number of the protruding portions 12 of the rotor 1 is 1, the rotor 1 rotates the protruding portion 12 for one rotation of the rotating magnetic field. It will move by one pitch. Therefore, low-speed rotation becomes possible. The control of supply and stop of the current for the step operation can be achieved by turning on / off the transistors Q ₂ , Q ₄ and Q ₆ . Further, during the step operation, the rotor 1 can be restrained at a desired position by continuing to supply a current to a specific stator winding, and positioning can be performed easily and reliably.

[Modifications] The present invention is not limited to the above-described embodiment, and for example, the following modifications are possible.

(1) Windings 2U, 2V, 2 of the first and second stators 2, 3
As shown in FIG. 14, a drive circuit for driving step motors of W, 3U, 3V, and 3W is a three-phase power supply 41 formed by Y-imaging first, second, and third AC power supplies 41U, 41V, and 41W. Output line 4
Connect each phase winding 2U, 2V, 2W, 3U, 3V, 3W to 2, 43, 44 via a half-wave rectifier circuit consisting of diodes 45, 46, 47,
The neutral point of each winding may be connected to the neutral point of the three-phase power supply 41. In this case, the step operation proceeds by one slot in one AC cycle of the applied power supply. The number of steps is controlled by the power supply cycle. When the induction motor is driven, a three-phase alternating current is supplied to each phase winding as in FIG.

(2) When the step motor is driven, three-phase or multi-phase alternating currents of opposite phases may be supplied to the first stator 2 and the second stator 3.

(3) A configuration other than three phases can be adopted.

(4) The rotor 1 can be achieved as a wound rotor.

(5) The difference between the number of the protrusions 12 of the rotor 1 and the number of the protrusions 19 of the stators 2 and 3 can be set to one or more various values.

〔The invention's effect〕

As described above, according to the present invention, one device can perform both the induction motor operation and the step motor operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view showing an electric motor device according to an embodiment of the present invention, FIG. 2 is a perspective view of a rotor partially omitted, and FIG. 3 is a partially omitted rotor core. Front view, FIG. 4 is a partially omitted front view of the stator core, FIG. 5 is a left side view of the stator core of FIG. 4 partially omitted, and FIG. 6 is a view showing the arrangement of windings in the stator. 7, FIG. 7 is a diagram showing how the windings are wound on the stator, FIG. 8 is a circuit diagram showing a drive circuit in the motor device of FIG. 1, and FIG. 9 is a drive circuit when the induction motor is operated. FIG. 10 is a perspective view schematically showing a relationship between a rotor and a stator during operation of the induction motor, FIG. 11 is a circuit diagram showing a drive circuit when a step motor is operated, and FIG. FIG. 13 is a waveform diagram showing the current of each phase winding when the step motor operates, and FIG. 13 shows the relationship between the rotor and the stator during the step motor operation. Perspective view showing the engagement schematically, FIG. 14 is a circuit diagram showing a driving circuit during step motor operation of a modified example. DESCRIPTION OF SYMBOLS 1 ... rotor, 2 ... 1st stator, 3 ... 2nd stator, 6 ... rotor core, 7 ... conductor, 9 ... groove, 12 ...
Projection, 15... First stator core, 16... First stator winding.

Claims (1)

(57) [Claims] A rotor having a plurality of grooves extending from respective central portions of a pair of main surfaces disposed orthogonal to a central axis toward respective outer peripheral portions. A plurality of conductors or windings formed from the center of one main surface of the rotor core to the center of the other main surface and inserted into the groove; and Means for short-circuiting a winding; and a first stator main surface facing one main surface of the rotor core, and the center of the first stator main surface is located at the center of the rotor core. Are arranged to coincide with each other and the first
A plurality of protrusions and grooves extending from the center of the stator main surface toward the outer peripheral edge, and the number of protrusions and grooves is different from the number of grooves on one main surface of the rotor core. And a second stator main surface facing the other main surface of the rotor core, and the center of the second stator main surface is the rotation of the rotor. The second core is arranged so as to coincide with the center of the
A second stator core having the same number of protrusions and grooves as the number of protrusions and grooves of the first stator core extending from the center of the stator main surface toward the outer peripheral edge; A first stator core, a first stator main surface, and an opposing gap between one main surface of the rotor core and a first stator so that a rotating magnetic field acts on the rotor; A first stator winding disposed on a main surface, and rotating through a facing gap between the second stator main surface of the second stator core and the other main surface of the rotor core. A second stator winding disposed on the main surface of the second stator so that a magnetic field acts on the rotor; and voltages in phase with each other are selected for the first and second stator windings. And a drive circuit capable of selectively applying voltages having opposite phases to each other.