JPH0216457A - Frequency generator - Google Patents

Abstract

PURPOSE:To cancel noise magnetic flux components and to improve the detection accuracy of the rotation frequency of a motor by arranging a canceling coil nearby a power generating coil in parallel to the border of a multipolar magnet and in series with the power generating coil. CONSTITUTION:The stator of a motor part consists of a driving coil 21, a bearing 22, and a yoke 23 and the rotor part consists of a main magnet 24 for driving, a shaft 25, and a rotor 26. An FG part consists of main magnetic flux 24 for driving the rotor part, a comb-shaped power generating coil 28 having a power generating element wire 27, and the comb-shaped canceling coil 29. The canceling coil 29 is arranged nearby the power generating coil 29, power generating element wires 31 and 32 of the canceling coil 29 are arranged almost in the same fitting phase with the power generating element wire 27 of the power generating coil 28, and the power generating coil 28 and canceling coil 29 are connected in series so that their outputs are opposite in phase to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applied to a motor, etc., and is a frequency generator (FrequenO-7Gθ
nerator: hereinafter abbreviated as FG).

BACKGROUND OF THE INVENTION In recent years, motors equipped with FC as rotor rotational frequency detection means have been increasingly used as motors for driving cylinders of video tape recorders (hereinafter abbreviated as VTR). With the demand for smaller size, lighter weight, and higher performance of equipment, there is a strong demand for smaller size, lighter weight, and higher performance.

As an FC that is smaller and lighter than before, yet has relatively high accuracy in detecting rotational angular velocity, a multi-pole magnetized magnetic pole surface is provided on one plane of a disk-shaped FG magnet, and this is fixed to the rotor.
On the stator side, a zigzag-shaped comb-tooth coil is arranged with a certain gap in between so as to face the magnetic pole surface of this FG magnet.A plane-opposed full-circumference integral type FC is used in the motor for driving the cylinder of a VTR, etc. has been done.

Here, since the FG is placed near the motor, it is affected by the noise magnetic flux generated by the current flowing in the stator winding of the motor, the noise magnetic flux caused by the drive motor, and the noise magnetic flux arriving from outside the motor. It is necessary to cancel these noise components, and many methods for canceling them have been proposed in the past. That-
An example is Japanese Patent Laid-Open No. 58-119759. The entire configuration will be explained below with reference to FIG.

FIG. 5 is a perspective view of a conventional motor employing FGi. As shown in the figure, the motor section includes a stator consisting of a drive coil 21, a bearing 22, a yoke 23 to which the drive coil 21 and the bearing 22 are completely fixed, and a main drive magnet 24.
and a rotor section consisting of a rotor 26 to which a shaft 26 is fixed, and the stator section and rotor section are opposed to each other with an axial gap interposed therebetween. The FG section includes a main drive magnet 24 of the rotor section that is supported so as to be freely rotatable relative to the stator section, and 2n+ of the number of poles of this main drive magnet 24.
1 (n = 1.2.3...) times the number of power generation coils 28 arranged parallel to the boundary of the magnetic poles of this main drive magnet 24, and a power generation coil 28 arranged around the outer periphery of the power generation coil 27. It consists of a canceling coil 29.

As shown in FIG. 6, the coil 29 is arranged around the outer periphery of the generating coil 28 so as to surround approximately the same amount of magnetic flux as the magnetic flux surrounded by the generating coil 28, out of the magnetic flux generated by the driving coil 21 being energized. It is arranged.

Further, the canceling coil 29 and the generating coil 28 are connected in series with each other so that the direction of the induced voltage is opposite to the magnetic flux in the same direction.

That is, as shown in FIG. smaller than the outer circumference. Further, in the illustrated state, the current flowing clockwise through each of the generating coils flows counterclockwise through the series-connected cancellation coils. That is, since the coils are oriented in opposite directions, the voltages induced for the same magnetic flux will be in opposite directions.

To explain the operation of FIG. 6 in the above configuration, one of the magnetic fluxes of the main drive magnet 24 closes its magnetic path via the rotor 26, and the other force is transmitted to the generating coil 28 and the canceling coil 2.
9. It passes through the drive coil 21 and closes its exit path via the yoke 23. Therefore, when the drive coil 21 is energized, a force acts between the drive main magnet 24 and the drive coil 21, causing the rotor to rotate. Due to this rotation, the generator coil 2
Since the magnetic flux interlinking with the generator coil 8 changes, an alternating current voltage is generated in the generator coil 28. Furthermore, an output is induced in the generator coil 28 by the magnetic flux generated by the drive coil 21, but an output of the same magnitude and opposite polarity is also induced in the canceling coil 29. In order to cancel this out, the FG specific output is set at the rotation frequency. Only the signal appears.

Problems to be Solved by the Invention However, in the conventional example described above, the noise magnetic flux component that is canceled out is limited to only the sum of the components that interlink the annular cancellation coil in the direction of the rotation axis of the rotor section.

Incidentally, although the noise magnetic flux component from the main drive magnet and the drive coil has an axial component, it is an alternating magnetic field in the circumferential direction. Therefore, the total sum of interlinking magnetic fluxes in the area surrounded by a ring of any diameter whose normal vector is oriented in the direction of the rotation axis is ○. This indicates that it is impossible to cancel out the magnetic field components in the circumferential direction in the cancellation coil. Therefore, it is impossible to cancel the noise magnetic flux from the drive coil, causing uneven rotation of the motor, resulting in a problem that the performance of the device cannot be satisfied.

In view of the above-mentioned problems, the present invention aims to improve the performance of the device by making the outputs of the generating coil and the canceling coil have opposite phases to cancel the noise magnetic flux.

Means for Solving the Problems In order to solve the above problems, the frequency generator of the present invention has the following features:
A canceling coil is arranged near the generating coil, and the generating line elements of the canceling coil are arranged so as to be in substantially the same installation phase as the generating line elements of the generating coil, and each output of the generating coil and the canceling coil is They are connected in series so that they are in opposite phases.

Function: By adopting the above-mentioned configuration, the present invention can also cancel the circumferential alternating magnetic field component, such as the noise s-terminal component from the driving main magnet and the driving coil, by providing the canceling coil with a generating line element. In addition, it is possible to cancel the noise magnetic flux component from outside the motor, and at the same time cancel it with the circular arc portion of the coil, and since no rotational frequency is generated in the cancellation coil, the rotational frequency detection accuracy can be improved while maintaining the rotational frequency output. It becomes possible to improve.

Example An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a motor equipped with an FG in a first embodiment of the present invention. The illustrated motor section includes a stator consisting of a drive coil 21, a bearing 22, and a yoke 23 to which the drive coil 21 and bearing 22 are fixed;
It is composed of a main driving magnet 24 and a rotor section consisting of a rotor 26 to which a shaft 25 is fixed, and the stator section and the rotor section are opposed to each other with an axial gap interposed therebetween. The FG section includes a main magnet 24 for driving the rotor section, which is supported so as to be freely rotatable relative to the stator section, and the main magnet 2 for driving the rotor section.
The comb has power generation line elements 27 arranged parallel to the boundaries of the magnetic poles of the main driving magnet 24, with the number of the poles being 2n-1-1 (n=1゜2.3...) times the number of poles of the main magnet 24 for driving. a tooth-shaped power generation coil 28;
The same comb-like canceling coil 2 arranged on the outer periphery
It consists of 9. In this embodiment, the number of poles of the main driving magnet 24 is eight, and the number of generating wire elements of the generating coil 28 and the canceling coil 29 is twenty-four. Here, the generating coil 28 and the canceling coil 29 are formed on one FG substrate 40. It goes without saying that the circumference, the generating coil 28, and the canceling coil 29 may have a substantially fan-shaped (or triangular) shape or the like other than the comb-teeth shape.

As shown in FIG. 1, this cancellation coil 29 has the same number of power generation line elements 30 disposed at approximately the same installation phase as the power generation line elements 27 of the power generation coil 28, and an arc-shaped power generation line. It consists of the elements 31 and 32.

The diameter Dci of the power generation line element 31 of the cancellation coil 29 is arranged to be larger than the outer diameter Dm of the main drive magnet 24. Also, the diameter Dco of the power generation wire element 32 is the same as that of the drive coil 21.
It is set to be approximately equal to the outer diameter nc of.

Here, the canceling coil 29 and the generating coil 28 are connected in series with each other so that the direction of the induced voltage is opposite to the magnetic flux in the same direction.

Therefore, in the illustrated state, a current flowing clockwise through each of the generator coils flows counterclockwise through the series-connected cancellation coils. That is, since the coils are oriented in opposite directions, the voltages induced for the same magnetic flux will be in opposite directions.

Next, the operation of this embodiment will be explained. Main drive magnet 2
One of the magnetic fluxes of 4 closes its magnetic path through the rotor 26,
The other one passes through the generating coil 28, the canceling coil 29, and the driving coil 21, and closes the magnetic path via the yoke 23. Therefore, when the drive coil 21 is energized, a force acts between the drive main magnet 24 and the drive coil 21, causing the rotor to rotate. This rotation changes the magnetic flux chained to the generator coil 28, so that an alternating current voltage is generated in the generator coil 28. However, the AC voltage generated by the power generation line element 28 is 2n+ of the magnetic flux distribution generated from the main drive magnet 24.
1 (n=1.2.3...), but the noise component due to the drive coil 21 and the noise proportional to the first-order component of the magnetic flux distribution of the main drive magnet 24 are also superimposed. are doing.

Here, the diameter Dci of the power generation wire element 31 of the cancellation coil 29
is arranged so as to be larger than the outer diameter Dm of the main drive magnet 24. Here, as shown in FIG. 3, the first-order component of the magnetic flux distribution of the main drive magnet 24 is difficult to attenuate even if the distance from the magnetic pole surface becomes large, but harmonic components such as the third and fifth order are It decays rapidly as the value increases. Therefore, in the canceling coil 29, 1 of the magnetic flux distribution of the main drive magnet 24 is
A voltage proportional to the noise of the next component is generated.

Furthermore, the magnetic flux generated by the drive coil 21 induces an output on the second day of the power generation coil. The outer diameter of the drive coil 21 and the outer diameter Dco of the power generation line element 3o of the cancellation coil 2e are substantially the same. In this case, the magnetic flux density generated by energizing the drive coil 21 at the position of the generating coil 28 and the value at the position of the canceling coil 29 are approximately equal.

Therefore, since a noise component voltage having approximately the same magnitude and opposite polarity as the noise component voltage superimposed on the output voltage of the generating coil 28 is also induced in the cancellation coil 29, only the rotational frequency signal is output to the FC output. appear. Therefore, the detection accuracy of the rotational speed of the rotor section is improved, and the performance of the device can be improved.

Note that in this embodiment, the generating coil 28 and the canceling coil 29 can be formed on the same substrate,
There is an advantage that the relative center deviation of each coil can be suppressed to zero, and assembly accuracy is also improved.

As described above, according to this embodiment, it is possible to obtain a compact, lightweight, and high-performance FC with a very simple configuration.

Next, a second embodiment of the present invention will be described.

FIG. 2 is a perspective view of a motor equipped with an FC in this embodiment. As shown in the figure, the motor section includes a stator consisting of a drive coil 21, a bearing 22, a yoke 23 to which the drive coil 21 and bearing 22 are fixed, and a main drive magnet 24.
The stator part and the rotor part are opposed to each other with an axial gap interposed therebetween.The FC part is the stator part. The FGG stones 34 of the rotor part are supported so as to be freely rotatable relative to the FGG stones 34, and the FGG stones 34 are disposed parallel to the boundary of the mother body of the FC magnets 34 in the same number as the approximate number of F(r magnets 34). A power generating coil 28 having a power generating line element 27 and a canceling coil 29 disposed on the inner circumference of the generating coil 28, and the canceling coil 29 are combined into one FGG.
It is formed on the plate 40.

As shown in FIG. 2, this canceling coil 29 includes the same number of generating line elements 30 and an arc-shaped generating line element 31 disposed at approximately the same installation phase as the generating line element 2 of the generating coil 28. It consists of .32. The diameters Dci and Dco of the generating wire elements 31 and 32 of the cancellation coil 29 are the diameters Dci and Dco of the generating coil 2
Diameters Dfi, Dfo of the arcuate connection portions 41 and 42 of 8
against Dco 2-Dci 2) Cape (Dfo 2-D
fi 2). Furthermore, power generation coil 2
The diameters Dfi, Df' of the arc connection portions 41 and 42 of No. 8
o is the outer diameter dimension Dm of the main drive magnet 24 and F (J1 stone 34
The outer diameter dimension D2. For Dm Cape Dfi D, G# D f.

This is the setting.

Here, the canceling coil 29 and the generating coil 28 are connected in series with each other so that the direction of the induced voltage is opposite to the magnetic flux in the same direction.

Accordingly, in the illustrated state, the current flowing in the respective generator coils in a full clockwise direction flows counterclockwise in the series-connected cancellation coils. That is, since the coils are oriented in opposite directions, the voltages induced for the same magnetic flux will be in opposite directions.

Next, the operation of this embodiment will be explained. Main drive magnet 2
One of the magnetic fluxes of 4 closes its magnetic path via the rotor 2e, and the other one closes its magnetic path through the generating coil 28, the canceling coil 291.
It passes through the drive coil 21 and closes its magnetic path via the yoke 23. Therefore, when the drive coil 21 is energized, a force acts between the drive main magnet 24 and the drive coil 21, causing the rotor to rotate. Due to this rotation, the magnetic flux interlinking with the generating coil 28 changes, so that an alternating current voltage is generated in the generating coil 28. However, although the AC voltage generated by the power generating line element 28 is proportional to the magnetic flux generated from the FG arsenal 34, noise components due to the drive coil 21 and noise proportional to the magnetic flux of the main drive magnet 24 are also superimposed. ing.

Here, as shown in the upper part of FIG. 4, the magnetic flux of the main driving magnet 24 is difficult to attenuate even if the distance from the polarized surface becomes large, but the magnetic flux of the FGG stone 34 is at the magnetization wavelength of the main driving magnet 24. On the other hand, since the magnetization wavelength of the FGi stone 34 is short, it rapidly attenuates as the distance increases. Therefore, the cancellation coil 29 generates a voltage proportional to the noise of the magnetic flux distribution of the main driving magnet 24.

Furthermore, the noise magnetic flux generated by the drive coil 21 induces an output in the power generation coil 28 .

However, by energizing the drive coil 21! The value of the noise magnetic flux density generated l1 at the position of the generating coil 28 and the value at the position of the canceling coil 29 are approximately equal.

Therefore, since a noise component voltage having approximately the same magnitude and opposite polarity as the noise component voltage superimposed on the output voltage of the generating coil 28 is induced in the cancellation coil 29, only the rotation frequency signal appears in the FG output. Therefore, the detection accuracy of the rotational speed of the rotor section is improved, and the performance of one device can be improved.

As described above, according to this embodiment, it is possible to obtain a small, lightweight, and high-performance FGi with a very simple configuration.

In addition, 1. In the second embodiment, the main drive magnet and the FG magnet have their magnetic pole surfaces formed in one plane, but the present invention is not limited to this. For example, the outer cylindrical surface of a cylindrical magnet Formed into a generator coil, drive coil,
It goes without saying that the cancellation coil may be constructed on a cylindrical surface.

Furthermore, the generating coil and the canceling coil do not necessarily need to be formed on one surface of one substrate, and may be formed on both sides of one F(r substrate.Furthermore, both coils are formed on two FG
It goes without saying that they may be separated on the board.

Effects of the Invention As described above, in the frequency generator of the present invention, the cancellation coil is disposed parallel to the boundary of the multipolar magnet, near the generating coil, and in series with the generating coil, and is connected to the generating line element of the generating coil. By adopting a configuration having the same number of power generation line elements, it is possible to cancel out the circumferential alternating magnetic field component of the noise magnetic flux component from the main drive magnet and the drive coil.
Further, since noise magnetic flux components from outside the motor can also be canceled out, it is possible to improve the detection accuracy of the rotational frequency of the motor. Therefore, it is possible to obtain a compact, lightweight, and high-performance FG with a simple configuration, which has the effect of improving the performance of equipment.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a motor equipped with an FG according to a first embodiment of the present invention, FIG. 2 is a perspective view of a motor equipped with an FGi according to a second embodiment of the present invention, FIGS. 3 and 4 is a diagram showing the relationship between distance from the magnetic pole surface and magnetic field strength, FIG. 5 is a perspective view of a motor equipped with a conventional canceling coil FG′ljr, and FIG. 6 is an exploded perspective view of a conventional FG. . 21...Drive coil, 24...Main magnet for drive, 28...Generation coil, 29...
・Cancellation coil. Name of agent: Patent attorney Shigetaka Awano and one other person Figure 1 7-m- 84~・ 28-・ x! iL vJ Koi] Thick recommended main magnet power generation coil 5 coils

Claims (1)

[Claims] a multipolar magnet, a power generation coil having a group of power generation wire elements parallel to the boundaries of the magnetic poles of the multipolar magnet, and disposed opposite to the magnetic pole surface of the multipolar magnet with a certain gap; A canceling element that is arranged parallel to the boundary of the pole magnet and near the power generation coil, is connected in series with the power generation coil, and has a group of power generation line elements that is approximately the same number as the power generation line elements of the power generation coil. a coil, the generating line elements of the canceling coil are arranged so as to be in substantially the same mounting phase as the generating line elements of the generating coil, and each output of the generating coil and the canceling coil is provided. A frequency generator characterized in that the frequency generators have opposite phases to each other.