JPH07274477A - Broadband speed motor and its driving method - Google Patents

Abstract

(57) [Summary] [Object] To provide a motor that can be driven by a single motor from a low speed to a high speed with a relatively narrow drive frequency and drive voltage, and a driving method thereof. [Structure] It has a structure capable of driving a hybrid type stepping motor composed of two or more similar motors, and armature windings of each phase are individually wound by both similar motors.
Moreover, the movable element or the stator on the side opposite to the armature has a structure that can generate a reluctance force corresponding to the armature winding, not the reluctance change due to the small teeth, and switches the connection direction of the windings of both poles. As a result, a broadband rotation speed motor that can drive both a hybrid stepping motor and a reluctance motor.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating machine, a linear actuator, a wide band rotational speed motor similar thereto, and a driving method thereof.

[0002]

Motors are used in a wide range of industrial fields,
Various types of motors are used in the optimal control method according to the application. Among them, servo motors are used in various applications such as FA devices such as robots and electric vehicles. One of the problems with this servo motor is driving in a wide range of rotation speeds. To drive at this wide range of rotation speed,
There are many problems. First, the drive voltage changes greatly in proportion to the rotation speed. The induction motor has a small rate of change in voltage with respect to the rotation speed, but other DC motors, synchronous motors, and stepping motors require a voltage proportional to the rotation speed for driving. Therefore, not only the driving device (driving circuit) becomes expensive, but also the control itself becomes difficult. Secondly, the excitation frequency of the core is in a wide band corresponding to the rotation speed, and the loss in the core is large. Thirdly, since the frequency at which the motor can best exert its performance is not so wide, it is impossible to obtain high thrust or high rotational force or high efficiency in the entire band. For example, in a servomotor, starting performance is important and starting power is large, and it is difficult to obtain a high rotation speed in a hybrid (HB) motor. High-speed performance is also required, and high-speed motors generally have poor drive characteristics at low speeds.

As a countermeasure against this, there is a method in which a transmission is used to control and rotate the motor within a narrow range of rotation speed at which the performance can be exhibited, and a necessary wide range of rotation speed change is handled by the transmission. However, in this method, the size of the device becomes large and mechanical loss occurs, so that energy efficiency also decreases.

Due to such a big problem, the size of devices such as a driving device and a transmission is increased. In particular, electric vehicles have recently been attracting attention, and the solution of this problem will lead to an increase in one-charge mileage and an improvement in startability.

Under the above circumstances, there is a demand for a motor that can be driven by a single motor from a low speed to a high speed with a relatively narrow driving frequency and driving voltage, and a driving method therefor.

[0006]

SUMMARY OF THE INVENTION In view of the above, an object of the present invention is to provide a motor that can be driven by a single motor from a low speed to a high speed with a relatively narrow driving frequency and driving voltage, and a driving method thereof. Was made as.

[0007]

The gist of the present invention is as follows. (1) It has a structure capable of driving a hybrid type stepping motor composed of two or more similar motors, and the armature windings are individually wound by the similar motors, and the armature windings are provided on the opposite side of the armature. The mover or the stator has a structure capable of generating a reluctance force due to the large teeth corresponding to the armature winding, and the connecting direction of the armature windings between the two or more similar motors is A wideband rotation speed motor, which can be switched between a hybrid stepping motor drive and a reluctance motor drive by changing it. (2) In order to reduce the pulsation of thrust or rotational force,
A wideband rotation speed motor comprising a plurality of wideband rotation speed motors according to the above (1) connected in multiple stages. (3) A driving method characterized in that the multi-stage wideband rotation speed motors described in (2) above are operated in parallel by the same driving device. (4) A driving method characterized in that the wideband rotation speed motor according to (1) or (2) is driven at a low rotation speed side with a hybrid stepping motor and at a high rotation speed side with a reluctance motor. (5) The driving method according to (3) or (4) above, which is driven by a sine wave.

The present invention will be described in detail below. A hybrid type (HB type) stepping motor, which is generally called, has a small magnetic pole at equal intervals on the rotor (hereinafter, small teeth for distinguishing from a magnetic pole of a permanent magnet, as in the embodiment).
Small teeth), and a large magnetic pole on which an armature winding corresponding to the number of phases n is wound on the armature of the stator (hereinafter, in order to distinguish from a magnetic pole of a permanent magnet, large teeth and large teeth). Note) and the tip thereof has small teeth at equal intervals corresponding to the small teeth of the rotor. Here, the small teeth at the tips of the large teeth of the armature are displaced from the small teeth of the rotor by 1 / n of the small tooth pitch. Two sets of this stator and rotor (hereinafter, one set is referred to as a small motor) become one HB type stepping motor, and in the meantime, a permanent magnet is provided on the rotor or the stator as shown in FIG. It has been incorporated. The two rotors are displaced by about a half pitch of the small teeth (the stator is not displaced. In principle, either the stator or the rotor is displaced).

The HB type stepping motor of the present invention is
Although it is essentially the same as the conventional HB type stepping motor, it may be different from the generally used HB type stepping motor as long as it operates as an HB type stepping motor. For example, the rotor generally has only small teeth, but the rotor may have small teeth at the tips of the projections of the large teeth as shown in FIG. 1 of the first embodiment. In this case, torque or thrust pulsation occurs in a single HB type stepping motor due to the large teeth of the stator, so several sets are connected as shown in FIG. 6 and the pulsation is reduced by shifting the phases respectively. May be.

The permanent magnet is generally located on either the rotor side or the stator side, but both may be used. Alternatively, it is assumed to include those that do not have permanent magnets and that each drive as a reluctance motor. Further, the armature winding has two armature windings wound simultaneously as shown in FIG. 4 in a generally used HB type stepping motor, but in the present invention, as shown in FIG. Each must be individually wrapped. In addition, the two stators are offset by half a pitch of the small teeth,
The rotor may be the one without small tooth gap. Generally H
The B-type stepping motor has a large number of phases of 5 and 4 but is 6
It may be more than three phases or three phases. Further, the HB type is not limited to two similar small motors, but may be one in which three or more small motors form one stepping motor. For example, it is a case where three reluctance motors having small teeth are set as one set and are displaced by 1/3 of the small tooth pitch. Drive,
Pulse drive, sine wave drive, or microstep drive may be used.

A reluctance motor is a motor that rotates because a rotating magnetic field generated by the armature winding of the stator produces a rotational force due to a change in magnetic resistance because the rotor has protruding poles. Further, since the conventional reluctance motor rotates following the rotating magnetic field of the stator, the rotational speed of the rotor matches the rotational speed of the rotating magnetic field of the stator. Moreover, the number of protruding poles of the rotor generally matches the number of poles. A vernier reluctance motor, which has been actively researched recently, may be used. This is because the number of protrusions of the stator and the rotor per pole is different by 1 or 2 or more, and the rotor makes a few revolutions for one rotation of the stator. Naturally, the reluctance motor referred to in the present invention may be of either type, and may have any structure as long as it operates on these driving principles.
For example, the salient poles of the rotor and the large teeth of the stator may have small teeth, which has the effect of reducing the loss generated at the salient poles. Also, two or more may be connected (for example,
One reluctance motor may have an N pole and the other may have an S pole. In this case, one reluctance motor pole number is the number of armature windings that are excited at the same time. ), There may be a permanent magnet as shown in FIG. The reluctance motor can be driven by pulse drive or sine wave drive without any waveform limitation. Whether the stepping motor or the reluctance motor is a rotary type or a linear type, there is no restriction on the structure or shape as long as it can operate.

In the present invention, in order to drive the HB type stepping motor and the reluctance motor by the same motor, the armature windings of each phase are individually wound by the respective small motors, and the side opposite to the armature is wound. The mover or stator has a structure that can generate a reluctance force with large teeth corresponding to the armature winding, not a change in reluctance with small teeth, and by changing the connection direction of the winding of each small motor. , Hybrid type stepping motor drive and reluctance motor drive are switched.

For example, as shown in FIG. 2, when the magnetic flux flows in the armature windings 4a and 4b of each small motor in the same direction as shown in the figure, the same as in the conventional HB type stepping motor of FIG. . On the other hand, the reluctance motor can be driven by switching the directions of the currents flowing through the windings 4a and 4b as shown in FIG. When driving with the three small reluctance motors described above, it is preferable to switch between a connection method that maximizes the total sum of reluctance forces due to the small teeth of the three small reluctance motors and a connection method that cancels the total sum. In the latter case, since there is no reluctance force due to the small teeth, it becomes possible to drive with the reluctance due to the large teeth.

The HB type stepping motor drive is generally driven in proportion to the small tooth pitch, and the reluctance motor drive is generally driven in proportion to the large tooth pitch. Therefore, even if the excitation frequency is the same, the drive rotation speed changes by almost one digit, so that a wide-band rotation speed motor can be obtained in a narrow excitation frequency band. That is, when this wide band rotation speed motor is driven at a low rotation speed side by a hybrid stepping motor and at a high rotation speed side by a reluctance motor, the frequency band of the drive circuit is smaller than that when driven by a single motor. 1
It would be good to be close to the order of magnitude.

In order to reduce the pulsation of thrust or rotational force, it is advisable to connect the broadband rotational speed motor of the present invention in multiple stages. These broadband multi-stage rotational speed motors may be operated in parallel by adding only the switching portion with the same driving device. As the driving device, a driving device for a conventional HB type stepping motor can be used. Generally, the driving may be pulse driving, but when pulsation of torque or thrust is a problem, driving may be performed with a sinusoidal wave and the excitation waveform is controlled.
Further, the HB type has a driving method such as a micro step, but this driving method may be adopted.

[0016]

【Example】

(Embodiment 1) FIGS. 1 to 12 show an embodiment of a linear motor that can be driven by switching between three-phase stepping motor drive and reluctance motor drive. Reference numeral 1 is a stator of an armature, 2 is a mover of a field element, and a permanent magnet 3 of the field element is sandwiched between the rotor 2a on the N pole side and 2b on the S pole side.
The stator side is divided into 1a and 1b so as to face a and 2b. Large teeth (large teeth) 7 of the core on the armature of the stator
a and 7b, 8a and 8b, 9a and 9b, each 3
Phase armature windings 4a and 4b, 5a and 5b, 6a and 6b are wound. 4a, 5a, 6a are wound on the large teeth 7a, 8a, 9a on the 1a side, and 4b, 5b, 6b are wound on the large teeth 7b, 8b, 9b on the 1b side. 1a to 9a form one small motor, 1b to 9b form another small motor, and these two form an HB type stepping motor. In the conventional stepping motor as shown in FIG. 4, 4a and 4b, 5a and 5b, 6a and 6b are one winding. Similar to the conventional stepping motor, the large teeth have small teeth (small teeth) 12, and the small teeth 1a and 1b have the same positional relationship.

The stator has small teeth which are present in the conventional stepping motor, and other large teeth 10a and 10b and 11a and 11b which are not present in the conventional stepping motor. The small teeth on 10a and 11a on the 2a side and the small teeth on 10b and 11b on the 2b side are
Like the conventional stepping motor, the teeth are shifted by a half pitch. The large teeth 7a and 7b on the rotation side of each phase, the small teeth of 8a and 8b, and the small teeth of 9a and 9b are offset by 120 ° corresponding to the phase of each phase. This is also the same as the conventional stepping motor.

FIGS. 1 to 3 explain the driving of a three-phase stepping motor. FIG. 1 shows aa ′ of FIG.
It is a view seen from above. Since an electric current flows through the armature winding 4a so that a magnetic flux flows in the direction of 4S ′, and the magnetic flux becomes the same as the magnetic flux of the field, the stator side 7a and the mover side 10a are Since the space between the teeth is sucked, the stator side 7a and the mover side 10
The small teeth of a are in the same position. FIG. 3 shows FIG.
It is a view as seen from cc 'of FIG.
The current flows so that the magnetic flux flows in the direction of, and the magnetic flux flow is different from the magnetic flux of the field, so that the teeth between the stator side 7b and the mover side 10b are repelled, so that the stator side 7b and the mover side are moved. The small teeth on the side 10b are offset by half a pitch.
That is, the armature windings 4a and 4b have the same directions 4S 'and 4S'.
When a current is caused to flow so that a magnetic flux flows in the direction of S ″, the positions shown in FIG. 1 and FIG. 3 are stabilized. Next, similarly, the armature windings 5a and 5b move in the same direction as 5S ′ When an electric current is caused to flow so that a magnetic flux flows in the 5S ″ direction, as shown in FIG. This behavior is
This is the same as driving a conventional stepping motor. However, while the number of matching small teeth 7a and 10a in FIG. 1 is 3, the number of matching small teeth 8a and 11a in FIG. 5 is one, and the thrust differs accordingly. Rush thrust pulsation occurs.

In this case, the motors are connected as shown in FIG. 6, and the phase relations thereof are shown in FIG. 7, in which the small teeth 8A and 11A and the small teeth 8B and 11B are in agreement. However, the number of coincidences of the combined small teeth is almost constant, and the pulsation of thrust can be reduced. It goes without saying that this stepping motor drive is generally suitable for low speed rotation.

On the other hand, FIGS. 9 to 12 show the case of reluctance drive. In this case, one side of the armature winding and one side
Unlike the case of driving the stepping motor of FIG. 2, the magnetic flux flows on the b side in the same direction in one magnetic circuit shown in FIG. The positions of the small teeth 2a, 1b, and 2b are 180 ° out of phase with each other, and the magnetic resistance of the magnetic circuit is substantially constant regardless of the rotational position of the rotor. That is, the reluctance force due to the positional relationship of the small teeth generated in the conventional stepping motor is not generated. Instead, reluctance power in large teeth works. For example,
As shown in FIG. 9, the armature coils 4a and 4b have the same structure as in FIG.
0, when an electric current is passed so that the magnetic flux flows as shown in FIG. 11, a reluctance force is generated so that the large teeth 7a and 10a coincide with each other. Next, in the armature coils 6a and 6b,
When an electric current is applied in the same relationship as a and 4b, it rotates so as to stabilize at the position shown in FIG. That is, it rotates about 1/3 of the large teeth pitch of the rotor.

As shown in FIG. 8, the changeover switch 16
When it is set to 17S side, it becomes the stepping motor drive.
On the R side, reluctance motor drive can be performed. Even in the case of the connection shown in FIG. 7, it is sufficient to connect them in parallel as shown in FIG. 7, and the pulsation of thrust can be reduced as described above. The drive circuit (drive device) 18 is the same as the conventional stepping motor drive device.

As described above, at the same frequency, the stepping motor drive corresponds to the small teeth and the reluctance drive corresponds to the large teeth, and the rotation speed is the ratio of the small teeth pitch to the large teeth pitch. Can be changed with. With a conventional stepping motor alone, it is necessary to change the frequency according to the number of rotations and also change the voltage, but the frequency can be changed ten times or more with the same voltage as the same frequency.

(Embodiment 2) FIG. 13 shows an embodiment of the present invention of a rotary type. It can drive a 4-phase HB type stepping motor and a vernier type reluctance motor. The principle and structure of the first embodiment are linear type and rotary type,
3 phase and 4 phase, conventional reluctance motor and vernier reluctance type are different, but the others are the same. This motor comprises an armature, which is the stator shown in FIG. 14, a rotor shown in FIG. 16, and a case 19.

FIG. 14 shows an armature having eight large teeth, and FIG. 15 is a sectional view taken along the line d--d 'of FIG. Permanent magnets 22 and cores 20 and 21 punched and laminated from electromagnetic steel sheets
And armature winding 23. Unlike the first embodiment, the permanent magnet is on the stator side. 16 is a rotor, and FIG. 17 is a side view thereof. At the ends of the large teeth of the armature core and the rotor core, there are small teeth for driving the HB type stepping motor. The relationship between the cores 20 and 21, the large teeth and the small teeth is the same as that of the embodiment. This rotor is made of the soft magnetic material 28, 29, 30 shown in FIG. 18 having a trapezoidal cross section and an insulating coating on the surface.
Is integrated in a concentric manner with 26 retaining rings,
It is fixed to the rotary shaft 27. Reference numeral 28 is a material corresponding to the small tooth portion of the large tooth, 29 is a material corresponding to the concave portion between the small teeth of the large tooth, and 30 is a material forming a concave portion corresponding to the large tooth. This rotor has 6 protrusions 25 and 8 stators.
Since it has a large number of teeth, it exhibits vernier reluctance characteristics in this relationship with respect to the four phases of the armature winding of the stator. Four
When a pulse is applied to one of the phases and eight pulses are sequentially applied (one rotation of the armature magnetic field), the rotor rotates about 1/3 rotation.

[0025]

The broadband motor of the present invention is a single motor that produces the largest torque and thrust of the motor and can be driven at a low speed by an HB type stepping motor and at a relatively high speed of reluctance. The motor can be driven. A general servo motor is required to have a steady-state characteristic, generally a high rotation characteristic, as well as a starting characteristic, but it is difficult to satisfy both of them. Since the wide-band rotation speed motor of the present invention has the starting characteristics of the HB type stepping motor and the high-speed rotation characteristics of the reluctance motor, the starting characteristics are the best among all motor models, and the high-speed motor characteristics are also excellent. . Salient poles (large teeth) for high-speed motors
At the tip of the wave, spatial harmonics are generated due to the wave shape, resulting in harmonic loss. This motor has small teeth at the tips of salient poles (large teeth), and has a structure that also suppresses eddy currents.

The wide-band rotation speed motor of the present invention can be easily controlled at a low speed by being driven by an HB type stepping motor, and can be rotated at a relatively high speed by being driven by a reluctance motor. That is, in the former drive, the drive corresponding to the small tooth can be performed, and in the latter reluctance motor drive, the drive corresponding to the large tooth can be performed at one frequency or with one device. This means that the driving device can drive a wide frequency range with a narrower frequency than a conventional single motor rotating in a wide band, which not only facilitates control but also lowers the cost of the driving device. It also leads to

Furthermore, if one conventional motor is used,
Since the excitation frequency also changes according to the number of revolutions, the excitation frequency of the motor core also becomes higher. Therefore, although the core loss increases and the efficiency decreases, since the wide-band speed motor of the present invention drives in a narrow range of frequencies, the excitation frequency of the core can be made lower than in the case of one conventional motor, Core loss can be reduced.

Recently, applications such as robots and electric vehicles that require start-up characteristics and high-speed characteristics have increased, and the present invention is suitable for these applications. In the case of an electric vehicle, not only the startability and the high-speed drivability but also the mileage per charge of the battery is a problem. This broadband motor is also superior in efficiency as described above. Furthermore, power regeneration is also important, but by changing the driving method (connection method) according to the number of revolutions, the induced voltage can be prevented from changing significantly, so charging the battery is more advantageous than the conventional one. is there.

[Brief description of drawings]

FIG. 1 shows an embodiment of a wide band rotation speed in which armature windings 4a, 4a
2b shows a stable position state in the case where a current is supplied in the stepping motor driving state, and FIG.
The side view seen from a '.

FIG. 2 is a sectional view taken along the line bb ′ of FIG.

FIG. 3 is a side view seen from cc ′ in FIG. 2.

FIG. 4 is a conventional HB type stepping motor corresponding to FIG.

FIG. 5 shows a stable position state when a current is applied to the armature windings 5a and 5b while the stepping motor is being driven.

FIG. 6 is an embodiment in which a wide band rotation speed motor of the present invention is connected.

FIG. 7 shows a phase relationship in a connected embodiment.

FIG. 8 shows an armature winding connection method and a switching method of the broadband rotation speed motor of the present invention.

FIG. 9 shows an example of wideband rotation speed in the armature windings 4a, 4
FIG. 11B is a side view as seen from aa ′ in FIG. 10, showing a stable position state when a current is being supplied in a state where b is a reluctance motor drive state.

FIG. 10 is a sectional view taken along the line bb ′ of FIG. 9.

11 is a side view seen from cc 'in FIG.

FIG. 12 is a stable position state when the armature windings 6a and 6b are driven with a current in a reluctance motor driving state.

FIG. 13 is an embodiment of the invention of the rotary type. 4-phase HB type stepping motor drive and vernier type reluctance motor drive are possible.

14 is an armature having eight large teeth, which is the stator in FIG.

FIG. 15 is a sectional view taken along line dd ′ of FIG.

16 is a front view of the rotor shown in FIG.

FIG. 17 is a side view of FIG.

FIG. 18 is a soft magnetic material having a trapezoidal cross section and an insulating coating on the surface.

[Explanation of symbols]

1 Wide band speed motor stators (armatures) 1A, 1B Connected wide band speed motor stators (armatures) 1a One small motor side (N pole side) stator 1b 1a Another small motor side (S pole side) stator paired with 2 Movable element (field element) of the wide band rotational speed motor 2A, 2B Movable element (field element) 2a movable element of the connected wide band rotational speed motor One small motor side (N pole side) mover 2b 2a paired with the other small motor side (S pole side) mover 3 Permanent magnets 4a, 5a, 6a Each three-phase 1a corresponding to
Side armature winding 4b, 5b, 6b 2a corresponding to each of the three phases
Side armature winding 4S ', 4S "Magnetic flux flow when current flows through the windings 4a and 4b in stepping motor drive state 4R', 4R" Winding current flows through reluctance motor in 4a 'and 4b " 4A ', 5A', 6A 'armature winding of one small motor of the motor 1A 4A ", 5A", 6A "armature winding of the other small motor of the motor 1A 7a, 8a, 9a 1a core large tooth (large magnetic pole) 8A 1A stator core large tooth (large magnetic pole) 1 8B 1B stator core large tooth (large magnetic pole) 1b 7b, 8b, 9b 1a Large core teeth (large magnetic poles) 10a, 11a 2a A pair of large rotor side teeth (large magnetic poles) 11A 2A Large rotor core teeth (large magnetic poles) 11B 2B rotor core Large teeth (large magnetic pole) 10b, 11b 2b side rotor side A set of large teeth (large magnetic pole) 12 Small teeth (small teeth) of the stator 13 Small teeth (small teeth) of the rotor 14 Connecting parts of the stators when connecting the motors 15 When connecting the motors Each of the rotor connection parts 16 Switching switch 17S Switch connection in case of stepping motor drive 17R Switch connection in case of reluctance motor drive 18 Drive device 19 Motor case 20, 21 Cores punched and laminated with electromagnetic steel sheet 22 Permanent magnet 23 Armature winding 24 Rotor core 25 Large rotor teeth 26 Stop ring 27 Rotating shaft 28, 29, 30 Soft magnetic material with trapezoidal cross section and insulating coating on the surface

Claims (5)

[Claims] 1. A hybrid stepping motor drivable structure comprising two or more similar motors, wherein armature windings are individually wound by the similar motors,
And, the movable element or the stator on the side opposite to the armature has a structure capable of generating a reluctance force due to the large teeth corresponding to the armature winding, and between the two or more similar motors,
A wideband rotation speed motor characterized by enabling switching between a hybrid stepping motor drive and a reluctance motor drive by changing the connection direction of the armature windings. 2. A wideband rotation speed motor comprising a plurality of wideband rotation speed motors according to claim 1, which are connected in multiple stages in order to reduce the pulsation of thrust or rotational force. 3. A driving method, wherein the multistage-connected wideband rotation speed motors according to claim 2 are operated in parallel by the same driving device. 4. A driving method characterized in that the wideband rotation speed motor according to claim 1 is driven by a hybrid stepping motor at a low rotation speed side and is driven by a reluctance motor at a high rotation speed side. 5. The driving method according to claim 3, wherein the driving is performed with a sine wave.