JPH0429551A - Motor - Google Patents

Abstract

PURPOSE:To make it possible to take out an output of a motor by constructing a motor of a rotor having a permanent magnet magnetized to have a plurality of poles, a stator including a stator winding, a gear rotating integrally with the rotor and having a reflecting surface provided, and a light-emitting light- sensing element disposed at a position opposite to the reflecting surface. CONSTITUTION:A rotor position detecting element 10 detects a rotational position of a rotor magnet 1. According to an output signal of the element, therefore, each phase of a stator winding 4 is electrified and a rotor 6 is made to rotate by the actuation of a magnetic force generated by the electrification. Accordingly, a reflecting plate 17 provided integrally with the rotor 6 rotates as well. At that time a light from a light-emitting part of a light-emitting light- sensing element 14 is applied to the reflecting plate 17, a reflected light therefrom enters a light-sensing part and thereby a voltage is generated in the light- emitting light-sensing element 14. By counting the number of times of generation of the voltage by a counting element provided inside a drive control circuit 12, therefore, the speed of rotation of the rotor 6 is detected and a control is executed by the drive control circuit 12 so that the number of revolutions of a motor is kept as prescribed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a motor used in video and audio equipment such as video tape recorders, audio cassette tape recorders, and video disc players.

Conventional technology In recent years, with the spread of inexpensive and high-performance ferrite magnets, and advances in small and high-performance Hall elements, integrated circuits, and power devices, AV equipment such as video tape recorders and digital audio recorders, and even laser printers have become popular. Brushless motors are used in OA equipment such as the following, and their range of applications continues to expand.

Normally, brushless motors require one position detection element and one armature energization control circuit for each phase, and two-phase or three-phase half-wave or full-wave drive systems are generally used. has been done.

FIG. 8 shows a side sectional view of a conventional motor, and FIG. 9 shows a Y-direction view of the conventional motor.

In FIG. 8, the rotor magnet 1 magnetized into multiple poles is
It is fixed to a back yoke 2 made of a magnetic material by adhesive or the like. Further, on the inner circumferential side of the rotor magnet 1, there is a laminated core 3 formed by laminating a plurality of thin plates of magnetic material such as silicon steel plates so that the outer circumferential surface faces the inner circumferential surface 1a of the rotor magnet 1. It is arranged. A thrower 3a for winding the stator winding 4 concentrically with the rotor magnet 1 is provided on the outer periphery of the laminated core 3.

Further, a motor shaft 5 is press-fitted into a boss portion 2a provided on the inner circumference of the back yoke 2. The motor shaft 5, rotor magnet 1, and back yoke 2 form a rotating arm of the motor. It is rotatably supported by a sliding bearing 9 made of alloy or the like.

Further, the housing 8 includes a portion for energizing the stator winding 4 at a position facing the laminated core 3 and separated by a predetermined gap amount;
A printed wiring board 11 for mounting a plurality of rotational position detection elements 10 such as Hall ICs for detecting the position of the rotor magnet 1 is fixed together with the laminated core 3 by screws 7 .

That is, the laminated core 3 is fixed to the housing 8 with the screws 7 with the printed wiring board 11 in between.

Therefore, the printed wiring board 11 includes an end portion 4a (not shown) of the stator winding 4 for energizing the stator winding 4;
A terminal 10a (not shown) of a rotor position detection element 10 made of a Hall element or the like is connected to provide position information of the rotor magnet 1 to a drive control circuit 12 (not shown) for drive control. There is. Note that this rotor position detection element 10 is arranged at a position facing the axial end surface 1b of the rotor magnet 1. The stator z5 is formed with the above configuration.

Further, as shown in FIGS. 8 and 9, a frequency generator for detecting the rotational speed of the motor uses a reflective part 13a and a non-reflective part by means such as etching or painting, which rotates with the rotation of the motor. 13b formed alternately at equal pitches in the circumferential direction, and a light emitting/receiving element that is located at a position facing the reflecting plate 13 and includes a light emitting part 14a (not shown) and a light receiving part 14b (not shown). It consists of 14. Furthermore, in order to detect the phase of the rotating arm of the motor, a unipolar magnetized PG is attached to the outer peripheral part 6a (not shown) of the rotating arm.
A magnet 15 is held integrally, and a phase detection element 16 consisting of a power generating coil, a Hall element, a magnetoresistive element, etc. is provided at a position facing the PG magnet 15.

Now, since the rotor position detection element 10 detects the rotational position of the rotor magnet 1 by detecting the magnetic poles of the rotor magnet 1, each phase of the stator winding 4 is detected according to this output signal. When the current is switched and energized, the rotating arm starts rotating due to the magnetic force generated by the stator winding 4.

Therefore, as the rotary support rotates, the reflecting plate 13, which is provided integrally with the rotary support, also starts to rotate. At this time, the light emitted from the light emitting part 14a (not shown) of the light emitting and receiving element 14 is irradiated onto the reflecting plate 13, and when the light is irradiated on the reflecting part 13a of the reflecting plate 13, it is reflected,
When the reflected light is incident on the light receiving section 14b (not shown), a voltage is generated at the terminal section 146 of the light emitting light receiving element 14. On the other hand, when the emitted light is irradiated onto the non-reflecting portion 13b, no voltage is generated at the terminal 14c because the reflected light does not enter the light receiving portion 14b (not shown). Therefore, by counting the number of times the voltage is generated by the counter inside the drive control circuit 12, the rotation speed of the rotor is detected, and the drive control circuit 12 controls the rotation speed of the motor to be constant. It was configured.

Furthermore, each time the PG magnet 15 passes the position of the phase detection element 16 due to the rotation of the motor, the phase detection element 1
6 generates pulses, so it is possible to detect the number of rotations, and to synchronize the rotational position of the rotating head and motor when this motor is used as the motor of the rotating head of a magnetic recording/reproducing device using a rotation controller. By taking this, it becomes possible to record on the tape or reproduce signals recorded on the tape.

In addition, conventionally, the number of position detection elements (
Many attempts have been made to reduce the number of digits (usually at least three are required), and a representative technology is U.S. Patent No. 3,577.
．． No. 053 (hereinafter abbreviated as Document 1). This document 1 describes that in a three-phase half-wave drive type brushless motor, first motors with different light reflectances are disposed on the rotor. Second. Third
An identification band having the following components is provided, a light beam is irradiated onto this identification band, and the reflected light is detected by a light receiving element, thereby outputting a change in the rotational position of the rotor as a three-step change in the output level of the light receiving element. ing.

In addition, as another attempt, we installed a north pole section on the rotor.

A position detection magnet is provided that constitutes the zero magnetized section and the S pole section, which are intermediate poles, and the change in the magnetic flux of this position detection magnet is detected by a magnetoelectric conversion element such as a Hall element, thereby increasing the output of the magnetoelectric conversion element. Changes in the rotational position of the rotor are output as changes in three levels.

Problems to be Solved by the Invention However, in a motor with a conventional configuration, (a) When extracting the output of the motor, it is necessary to provide an output transmission member such as a gear or a pulley on the spindle of the motor. .

(b) Cost increases because the number of Hall elements increases.

(c) In order to improve rotational accuracy, precision is required for the installation of Hall elements, and an inspection process is required when creating a motor, leading to an increase in cost (particularly when three Hall elements are required, Become).

(d) In order to detect the rotational phase of the motor, it is necessary to newly install a PG magnet or to separately magnetize a part of the rotor magnet for position detection, which increases the cost due to the number of man-hours. It had become.

In addition, in the method shown in Document 1, the number of components increases because it is necessary to provide three identification bands with different light reflectances, a light emitting element that irradiates the identification band with light, and a light receiving element that receives the reflected light. However, since the light-emitting element and the light-receiving element are currently more expensive than position detecting elements using magneto-electric conversion elements, there is no advantage in reducing the number of position detecting elements in terms of cost.

In addition, it is extremely difficult to zero-magnetize the position detection magnet, which is the intermediate pole, and even if it is magnetized,
The problem was that the magnetic field in that part was extremely unstable and easily deteriorated over time.

In order to solve the above problems, an object of the first invention is to provide a transmission gear for extracting the output of the motor to the outside in a part of the frequency generator for detecting the rotation speed of the motor, and to connect the motor shaft, etc. It is an object of the present invention to provide a motor capable of taking out the output of the motor without newly providing a transmission part.

The purpose of the second invention is to generate a magnetic flux for PG for detecting the rotational phase of the motor by using parts constituting a frequency generator for detecting the rotational speed of the motor. To provide a motor that does not require separate magnetization for PG on a part of the magnet.

Further, an object of the third invention is to generate a rotor position signal for phase switching of a three-phase electric motor using a unique position detection element, and to detect the rotational speed of the motor by using the same parts as the rotor position signal generating means. An object of the present invention is to provide a motor configured with a frequency generator that detects.

Means for solving the problem In order to achieve the above object, the technical means of the first invention are as follows:
A rotor having an annular or disc-shaped permanent magnet magnetized to multiple poles, a stator including a stator winding arranged opposite to the rotor, and a rotor that rotates integrally with the rotor. However, this is because it is composed of a gear provided with a reflective surface and a light emitting/receiving element disposed at a position facing the reflective surface of the gear.

Furthermore, the technical means of the second invention includes a rotor having an annular or disc-shaped permanent magnet magnetized to multiple poles, and a stator winding arranged opposite to the rotor. a stator, a magnetic flux shielding member that shields a portion of the leakage magnetic flux of the permanent magnet and has a plurality of reflective parts having different light reflectances at equal intervals; and a position facing the reflective part of the magnetic flux shielding member. This is due to the fact that the light emitting and receiving elements are arranged in the

Finally, the technical means of the third invention includes a rotor having an annular or disc-shaped permanent magnet magnetized with multiple poles, and a stator winding arranged opposite to the rotor. a magnetic flux shielding member that shields a portion of the leakage magnetic flux of the permanent magnet and has a plurality of reflective parts having different light reflectances at equal intervals; and a magnetic flux shielding member that faces the reflective part of the magnetic flux shielding member. The shielding area of the magnetic flux shielding member is 1 in the boundary area between the N and S poles of the permanent magnets of the rotor.
This is due to the fact that it is provided in individual boundary areas.

Effect The effect of the technical means of the first invention is that a transmission gear for extracting the output of the motor to the outside is provided in a part of the frequency generator for detecting the rotation speed of the motor, so that the motor shaft, etc. It is possible to take out the output of the motor without adding new transmission parts to the motor.

The effect of the technical means of the second invention is that magnetic flux generation for PG for detecting the rotational phase of the motor is performed by using parts constituting a frequency generator for detecting the rotational speed of the motor. The reason is that there is no need to separately magnetize a new magnet or a part of the rotor magnet for PG.

Finally, the effect of the technical means of the third invention is that, with the above-described configuration, a rotor position signal for phase switching of a three-phase motor is generated using only one position detection element, and the rotor position The present invention is based on the fact that the frequency generator for detecting the rotational speed of the motor is constructed of the same parts as the signal generating means.

EXAMPLE Hereinafter, an example of the first invention will be described with reference to the drawings.

FIG. 1 is a side sectional view of a motor in an embodiment of the first invention, and FIG. 2 is a Y-axis view of the motor in an embodiment of the first invention.
It is a directional view.

In FIG. 1, a rotor magnet 1 magnetized into multiple poles is
It is fixed to a back yoke 2 made of a magnetic material by adhesive or the like. Further, on the inner circumferential side of the rotor magnet 1, there is a laminated core 3 formed by laminating a plurality of thin plates of magnetic material such as silicon steel plates so that the outer circumferential surface faces the inner circumferential surface 1a of the rotor magnet 1. It is arranged. A thrower 3a for winding the stator winding 4 concentrically with the rotor magnet 1 is provided on the outer periphery of the laminated core 3.

Further, a motor shaft 5 is press-fitted into a boss portion 2a provided on the inner circumference of the back yoke 2. The motor shaft 5, the rotor magnet 1, and the back yoke 2 form the rotational axis of the motor. It is rotatably supported by a sliding bearing 9 made of a material such as a slide bearing 9, etc.

Further, the housing 8 includes a portion for energizing the stator winding 4 at a position facing the laminated core 3 with a predetermined gap distance therebetween;
A printed wiring board 11 is fixed together with the laminated core 3 by screws 7 to which a plurality of rotor position detection elements 0 made of Hall ICs and the like for detecting the position of the rotor magnet 1 are attached.

That is, the laminated core 3 is fixed to the housing 8 with the screws 7 with the printed wiring board 11 in between.

Therefore, the printed wiring board 11 includes an end portion 4a (not shown) of the stator winding 4 for energizing the stator winding 4;
A terminal 10a (not shown) of a rotor position detection element 10 made of a Hall element or the like is connected to provide position information of the rotor magnet 1 to a drive control circuit 12 (not shown) for drive control. There is. Note that this rotor position detection element 10 is arranged at a position facing the axial end surface 1b of the rotor magnet 1. The stator λ balls are formed by the above configuration.

In addition, as shown in Figures 1 and 2, the frequency generator for detecting the rotational speed of the motor rotates together with the rotor of the motor, and its outer periphery is cut by etching, cutting, punching, etc. By forming the gear part 17a, a reflective part 17b and a non-reflective (transmissive) part 17c are formed, and the reflective plate 17 provided on the axial end face of the rotary support is opposed to the reflective plate 17, and , the reflective section 1 of the gear section 17a
7b and non-reflective portions 17c are provided at alternate positions at equal pitches in the circumferential direction, and a light emitting/light receiving element 14 consisting of a light emitting portion 14a (not shown) and a light receiving portion 14b (not shown) is provided. . The gear portion 17a of the reflector 17 also includes a transmission gear 18 for transmitting the rotational force of the motor to other parts.
(not shown) is provided.

Now, since the rotor position detection element 10 detects the rotational position of the rotor magnet 1 by detecting the magnetic poles of the rotor magnet 1, each phase of the stator winding 4 is detected according to this output signal. When the current is switched and energized, the rotating arm starts rotating due to the magnetic force generated by the stator winding 4.

Therefore, as the rotating support rotates, the reflecting plate 17, which is provided integrally with the rotating support, also starts rotating. At this time, the light emitted from the light emitting part 14a (not shown) of the light emitting and receiving element 14 is irradiated onto the reflecting plate 17, and when the light is irradiated onto the reflecting part 17b of the reflecting plate 17, it is reflected,
When the reflected light is incident on the light receiving section 14b (not shown), a voltage is generated at the terminal section 14c of the light emitting light receiving element 14. On the other hand, when the emitted light is irradiated onto the non-reflecting portion 17c, the reflected light does not enter the light receiving portion 14b (not shown), so no voltage is generated at the terminal 14c. Therefore, by counting the number of times the voltage is generated by the counting section inside the drive control circuit 12, the rotation speed of the rotor is detected, and the drive control circuit 12 keeps the rotation speed of the motor constant. It controls the rotation speed. Furthermore, as the rotary ring is rotated, the gear portion 17a of the reflecting plate 17, which is integrally formed with the rotary ring, also starts to rotate.1. The transmission gear 18 meshing with the gear portion 17a also rotates, making it possible to transmit the rotation of the motor to the outside.

Next, the operation of this embodiment will be explained.

By forming gears on the outer periphery of the reflector that makes up the frequency generator as described above, it is possible to transmit the motor output to the outside without increasing the number of parts, even though it has a very simple configuration. can do.

In this example, the reflection part of the frequency generator was provided on the axial end face of the rotor, but the position where the frequency generator is provided is not limited to this example; for example, it may be attached to the motor shaft, etc. Also good.

Further, in this embodiment, a brushless circumferentially opposed motor has been described, but the present invention is not limited to the type of motor.

In this example, a reflection type optical frequency generator was used, but there is no problem in using a transmitted light type frequency generator, but it is possible to reduce the thickness and the complexity of the adjustment process. Considering this, the reflection method in this embodiment is more advantageous.

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

FIG. 3 is a side sectional view of a motor in an embodiment of the second invention, and FIG. 4 is a Y-axis view of the motor in an embodiment of the second invention.
It is a directional view.

In FIG. 3, the rotor magnet 1 magnetized into multiple poles is
It is fixed to a back yoke 2 made of a magnetic material by adhesive or the like. Further, on the inner circumferential side of the rotor magnet 1, there is a laminated core 3 formed by laminating a plurality of thin plates of magnetic material such as silicon steel plates so that the outer circumferential surface faces the inner circumferential surface 1a of the rotor magnet 1. It is arranged. A thrower 3a for winding the stator winding 4 concentrically with the rotor magnet 1 is provided on the outer periphery of the laminated core 3.

Further, a motor shaft 5 is press-fitted into a boss portion 2a provided on the inner circumference of the back yoke 2. The motor shaft 5, rotor magnet 1, and back yoke 2 form a rotating arm of the motor. It is rotatably supported by a sliding bearing 9 made of alloy or the like.

Further, the housing 8 includes a portion for energizing the stator winding 4 at a position facing the laminated core 3 and separated by a predetermined gap amount;
A printed wiring board 11 for mounting a plurality of rotational position detection elements 10 such as Hall ICs for detecting the position of the rotor magnet 1 is fixed together with the laminated core 3 by screws 7 .

That is, the laminated core 3 is fixed to the housing 8 with the screws 7 with the printed wiring board 11 in between.

Therefore, the printed wiring board 11 includes an end portion 4a (not shown) of the stator winding 4 for energizing the stator winding 4;
A terminal 10a (not shown) of a rotor position detection element 10 made of a Hall element or the like is connected to provide position information of the rotor magnet 1 to a drive control circuit 12 (not shown) for drive control. ing. Note that this rotor position detection element 10 is arranged at a position facing the axial end surface 1b of the rotor magnet 1. The stator λ balls are formed by the above configuration.

Further, as shown in FIGS. 3 and 4, a frequency generator for detecting the rotation speed of the motor rotates as the motor rotates, and is attached to the axial end surface 1b of the rotor magnet 1 by means of adhesive or the like. The reflective part 19b and the non-reflective (transmissive) part 19c are formed by forming slit parts 19a on the outer periphery of the reflective part 19a by etching, cutting, punching, etc., so that the reflective part 19b and the non-reflective (transmissive) part 19c are fixed to each other by means of a magnetic material. and a reflecting plate 19 provided on the axial end face of the rotary plate;
A light emitting section 14a (not shown) is provided at a position facing the reflector 19.
and a light-receiving section 14b (not shown).
4. Further, the reflection plate 19 has a substantially annular shape so as to direct the magnetic flux generated from the axial end face 1b of the rotor magnet 1, and is provided with a cutout portion 19d at a specific rotational phase of the rotor magnet 1. A power generating coil and a Hall element are located at a position facing the notch 19d.

A phase detection element 20 made of a magnetoresistive element or the like is provided.

Now, since the rotor position detection element 10 detects the rotational position of the rotor magnet 1 by detecting the magnetic poles of the rotor magnet 1, each phase of the stator winding 4 is detected according to this output signal. When the current is switched and energized, the stator winding 4 starts rotating due to the magnetic force generated.

Therefore, as the rotating flat plate rotates, the magnetic flux shielding member 19 provided integrally with the rotating flat plate also starts rotating. At that time, the light emitting part 14a of the light emitting light receiving element 14 (
When the light emitted from the magnetic flux shielding member 19 is irradiated with the light emitted from the magnetic flux shielding member 19 (not shown), it is reflected when the light is irradiated with the reflecting part 19b of the magnetic flux shielding member 19, and the reflected light is reflected to the light receiving part 14b (not shown). By being incident, a voltage is generated at the terminal portion 14c of the light emitting/receiving element 14. On the other hand, when the emitted light is irradiated onto the non-reflecting portion 19c, the reflected light does not enter the light receiving portion 14b (not shown), so no voltage is generated at the terminal 14c. Therefore, by counting the number of times the voltage is generated by the counter inside the drive control circuit 12,
The rotation speed of the motor is detected, and the drive control circuit 12 controls the rotation speed of the motor to keep it constant.

Furthermore, as the motor rotates, the phase detection element 20 generates a pulse every time the notch 19d passes the position of the phase detection element 20, so it is possible to detect the number of rotations and to operate a magnetic recording/reproducing device using a rotary head. When this motor is used as the motor for the rotating head, by synchronizing the rotational position of the rotating head and the motor, it becomes possible to record on the tape or reproduce signals recorded on the tape. .

Next, the operation of this embodiment will be explained.

As mentioned above, the reflector that constitutes the frequency generator is made of a magnetic material, and its shape shields most of the magnetic flux generated from the axial end surface of the rotor magnet to the axial end surface of the rotor magnet, and some of the magnetic flux is It allows magnetic flux to pass through it, and by fixing it to the axial end face of the rotor magnet, it has a very simple configuration and can detect the rotational phase and rotational speed of the motor without increasing the number of parts. I can do it.

Further, as shown in FIG. 4, by forming the slit portion in the shape of a gear, and by providing a transmission gear that meshes with the gear, the output of the motor can be extracted.

Although the present embodiment has been described using a brushless circumferentially opposed motor, the present invention is not limited to the type of motor.

Furthermore, in this embodiment, the slit portion of the reflector constituting the frequency generator was provided on the outer periphery of the reflector, but the position where the slit portion is provided is not limited to the outer periphery, for example, around the rotor magnet. If installed in the correct position, the material of the rotor magnet will
In the case of ferrite type, it is possible to make the slit opening a non-reflective part, and in the case of neodymium type, the surface is plated with nickel, etc., so the reflective plate can be painted black etc. By lowering the reflectance, the slit opening can be used as a reflective section.

In addition, in this embodiment, the reflective plate constituting the frequency generator was provided with a reflective part and a non-reflective part by providing slits in the reflective plate. The frequency generator may be configured by alternating the reflective portions and non-reflective portions at an equal pitch by changing the frequency generator.The frequency generator is not limited to this embodiment.

In this example, a reflection type optical frequency generator was used, but there is no problem in using a transmitted light type frequency generator, but considering the slimming down and the complexity of the adjustment process. , the reflection method in this embodiment is more advantageous.

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

FIG. 5 is a side sectional view of a motor in an embodiment of the third invention, and FIG. 6 is a Y-axis view of the motor in an embodiment of the third invention.
The direction arrow view and FIG. 7 are output waveform diagrams of the rotor position detection element in an embodiment of the third invention.

In FIG. 5, the rotor magnet 1 magnetized into multiple poles is
It is fixed to a back yoke 2 made of a magnetic material by adhesive or the like. Further, on the inner circumferential side of the rotor magnet 1, there is a laminated core 3 formed by laminating a plurality of thin plates of magnetic material such as silicon steel plates so that the outer circumferential surface faces the inner circumferential surface 1a of the rotor magnet 1. It is arranged. A slot 3 a is provided on the outer periphery of the laminated core 3 for winding the stator winding 4 concentrically with the rotor magnet 1 .

Further, a motor shaft 5 is press-fitted into a boss portion 2a provided on the inner circumference of the back yoke 2. The motor shaft 5, rotor magnet 1, and back yoke 2 form a rotating arm of the motor. It is rotatably supported by a sliding bearing 9 made of alloy or the like.

Further, the housing 8 includes a portion for energizing the stator winding 4 at a position facing the laminated core 3 and separated by a predetermined gap amount;
A printed wiring board 11 is fixed together with the laminated core 3 by screws 7 to which a single rotational position detection element 10 made of a Hall IC or the like for detecting the position of the rotor magnet 1 is attached.

That is, the laminated core 3 is fixed to the housing 8 with the screws 7 with the printed wiring board 11 in between.

Therefore, the printed wiring board 11 includes an end portion 4a (not shown) of the stator winding 4 for energizing the stator winding 4;
A terminal 10a (not shown) of a rotor position detection element 10 made of a Hall element or the like for providing position information of the rotor magnet 1 to a drive control circuit 12 (not shown) for drive control.
are connected. Note that this rotor position detection element 1
0 is arranged at a position facing the axial end surface 1b of the rotor magnet 1. The above-described configuration forms the stator λ.

In addition, as shown in FIGS. 5 and 6, a frequency generator for detecting the rotation speed of the motor rotates together with the rotating arm of the motor, and is attached to the axial end surface 1b of the rotor magnet 1. By forming slits 21a on the outer periphery by means of etching, cutting, punching, etc., the reflective parts 21b and non-reflective (transparent) parts are formed alternately at equal pitches. ) part 21c, and is provided on the axial end face of the rotating support.
1, and a light emitting part 14a at a position facing the magnetic flux shielding member 21.
(not shown) and a light-emitting light-receiving element 14 consisting of a light-receiving section 14b (not shown).

Further, the magnetic flux shielding member 21 has a substantially annular shape so as to prevent the magnetic flux generated from the axial end face 1b of the rotor magnet 1. Cutouts 21d (four locations in this embodiment) are provided at positions adjacent to the N and S poles. A phase detection element 10 consisting of a power generating coil, a Hall element, a magnetoresistive element, etc. is provided at a position facing the notch 21d.

Now, since the rotor position detection element 10 detects the rotational position of the rotor magnet 1 by detecting the magnetic poles of the rotor magnet 1, each phase of the stator winding 4 is detected according to this output signal. When the current is switched and energized, the stator winding 4 starts rotating due to the magnetic force generated.

Therefore, as the rotating flat plate rotates, the magnetic flux shielding member 21 provided integrally with the rotating flat plate also starts rotating. At that time, the light emitting part 14a of the light emitting light receiving element 14 (
When the light emitted from the magnetic flux shielding member 21 is irradiated with the light emitted from the magnetic flux shielding member 21 (not shown), it is reflected when the light is irradiated onto the reflecting part 21b of the magnetic flux shielding member 21, and the reflected light enters the light receiving part 14b (not shown). As a result, a voltage is generated at the terminal portion 14c of the light emitting/receiving element 14. On the other hand, when the emitted light is irradiated onto the non-reflecting portion 21c, the reflected light does not enter the light receiving portion 14b (not shown), so no voltage is generated at the terminal 14c. Therefore, by counting the number of times the voltage is generated by a counter inside the drive control circuit 12, the rotation speed of the normal rotation is detected, and the drive control circuit 12 adjusts the rotation speed so that the rotation speed of the motor is kept constant. is under control.

Here, a rotor position detection element 10 consisting of a Hall element etc.
The operating principle will be briefly explained.

The Hall element has four terminals, two terminals that supply bias current to the Hall element, and two terminals that output the output voltage of the rotor position detection element. Here, the Hall output voltage due to magnetic flux per unit area is
It can be expressed by the following equation (1).

H EH= −・IH−B−CO5θ+V@ ・・
・(1)Tap, EH: 8 for Hall output voltage: Hall element packing density B: Magnetic flux density iH: Hall element bias current Vll2 Hall element unbalance voltage d: Hall element thickness θ: Incident magnetic flux From equation (1), it can be seen that the Hall output voltage is proportional to the magnetic flux passing through the Hall element and the bias current.

Further, when the direction of the magnetic flux changes, the Hall output voltage in equation (1) has a reverse polarity, and switching of the magnetic pole can be detected.

In FIG. 5, the rotor position detection element 10 is installed to face the magnetic flux shielding member 21, and the magnetic flux of the position detection portion of the rotor magnet 1 to which the magnetic flux shielding member 21 is fixed detects the rotor position. It will pass through the element 10. Now, let us assume that when the rotor position detection element 10 is located at the N pole position, a constant bias current is flowing so that the Hall output voltage is output to the positive pole side, and the following description will be made. First, place the rotor position detection element 1 at the N pole position.
When there is 0, the maximum Hall output voltage is generated on the positive side. Next, when the rotor position detection element 10 is located at the position where the magnetic flux shielding member 21 is attached, the magnetic flux of the rotor magnet 1 is blocked by the magnetic flux shielding member 21 so that the magnetic flux does not pass through the rotor position detection element 10. Therefore, a Hall output voltage at an intermediate potential is generated. Furthermore, when the rotor position detection element 10 is located at the S pole position, the maximum Hall output voltage is generated on the negative pole side.

FIG. 7 shows the rotor position detection element 1 at the N pole position in FIG. 6.
0, and the rotating flat is rotating counterclockwise (counterclockwise) when viewed from the direction of stator λ2. FIG. As mentioned above, the Hall output voltage has a maximum value on the positive pole side at the N pole position, and the maximum value on the positive pole side is
An intermediate potential is generated at the fixed position, and a maximum value is generated on the negative electrode side at the S pole position.

As described above, with the pair of N and S poles of the rotor magnet 1 as a reference, the magnetic flux shielding member 21 is fixed at a position where the N and S poles are adjacent to each other, and the rotor position detection element 10 is installed at a position facing each other. By doing so, it becomes possible to generate three types of rotor position signals for 360 degrees of electrical angle based on the N and S poles of the rotor magnet 1 using the only rotor position detection element 10.

Next, the operation of this embodiment will be explained.

As mentioned above, the reflector that constitutes the frequency generator is made of a magnetic material, and its shape allows the axial end face of the rotor magnet to shield most of the magnetic flux generated from the axial end face of the rotor magnet, and partially By fixedly printing on the axial end face of the rotor magnet, it has a very simple configuration and does not require an increase in the number of parts. It becomes possible to generate a rotor position signal for phase switching.

Further, by forming the slit portion in the shape of a gear as shown in FIG. 6, it is also possible to extract the output of the motor by providing a transmission gear that meshes with the gear.

In this embodiment, a brushless circumferentially opposed motor has been described, but the present invention is not limited to the type of motor.

Furthermore, in this embodiment, the slit portion of the reflection plate constituting the frequency generator was provided on the outer periphery of the reflection plate, but the position where the slit portion is provided is not limited to the outer periphery, for example, at the position of the rotor magnet. If the material of the rotor magnet is ferrite, the slit opening can be made into a non-reflective part, and if the rotor magnet is made of neodymium, the surface is plated with nickel, etc. Therefore, the slit opening can be used as a reflective part by painting the reflective plate black or the like to lower the reflectance.

In addition, in this embodiment, the reflective plate constituting the frequency generator was provided with a reflective part and a non-reflective part by providing a slit in the reflective plate, but the reflectance of the reflective plate was increased by etching, painting, etc. Alternatively, the frequency generator may be configured by alternately forming reflective portions and non-reflective portions at equal pitches, and the manner of configuring the frequency generator is not limited to this embodiment.

In this example, a reflective type optical frequency generator was used, but there is no problem in using a transmitted light type frequency generator, but considering the slimming down and the complexity of the adjustment process. Therefore, the reflection method in this embodiment is more advantageous.

Effects of the Invention As described above, the motor according to the first invention includes a rotor having an annular or disc-shaped permanent magnet magnetized with a plurality of poles, and a stator disposed opposite to the rotor. By providing a stator including windings, a gear that rotates integrally with the rotor and is provided with a reflective surface, and a light-emitting/receiving element placed at a position facing the reflective surface of the gear, it is extremely effective. Although it has a simple configuration, it has the feature of being able to transmit the output of the motor to the outside without increasing the number of parts, and has great practical effects.

On the other hand, according to the motor according to the second aspect of the invention, there is provided a rotor having an annular or disc-shaped permanent magnet magnetized to a plurality of poles, and a stator winding arranged opposite to the rotor. A stator consisting of a stator, and a plurality of pairs of reflecting parts made of a magnetic material that shield some of the leakage magnetic flux of the permanent magnet, and having alternately different light reflectances, or a plurality of reflecting parts arranged at equal intervals. The structure consists of a magnetic flux shielding member having a slit portion, and a light emitting/receiving element placed opposite the reflecting portion or slit portion of the magnetic flux shielding member, which increases the number of parts even though it has a very simple configuration. It has the feature of being able to detect the rotational phase and rotational speed of the motor without having to do so, and has great practical effects.

Next, according to the motor according to the third aspect of the invention, there is provided a rotor having an annular or disk-shaped permanent magnet magnetized to a plurality of poles, and a stator winding disposed opposite to the rotor. and a stator made of a magnetic material, which shields a part of the leakage magnetic flux of the permanent magnet, and which includes a plurality of pairs of reflecting parts or a plurality of equidistantly arranged reflecting parts having alternately different light reflectances. The magnetic flux shielding member includes a magnetic flux shielding member having a slit portion, and a light emitting/receiving element disposed at a position facing the reflecting portion or the slit portion of the magnetic flux shielding member. Because it is installed adjacent to the N and S poles based on the pair, it has a very simple configuration and can be used as the only position detection element for phase switching of a three-phase motor without increasing the number of parts. It has the characteristic that it is possible to generate a rotor position signal, and its practical effects are great.

[Brief explanation of drawings]

FIG. 1 is a side sectional view of a motor in an embodiment of the first invention, and FIG. 2 is a Y-axis view of the motor in an embodiment of the first invention.
3 is a side sectional view of the motor in an embodiment of the second invention, FIG. 4 is a Y-direction view of the motor in an embodiment of the second invention, and FIG. 5 is a sectional view of the motor in the embodiment of the second invention. 6 is a side sectional view of a motor in an embodiment of the third invention, FIG. 6 is a Y-direction arrow view of the motor in an embodiment of the third invention, and FIG. 7 is a rotor in an embodiment of the third invention. FIG. 8 is a side sectional view of a conventional motor, and FIG. 9 is a view of the conventional motor in the Y direction. dan...rotor, 14...light emitting light receiving element, 17a
...Gear, 19...Magnetic flux shielding member, λj...Stator.

Claims (3)

[Claims] (1) A stator including a rotor having an annular or disk-shaped permanent magnet magnetized into multiple poles, a stator winding arranged opposite to the rotor, and the rotor. A motor comprising: a gear that rotates integrally and is provided with a reflective surface; and a light emitting/receiving element disposed at a position facing the reflective surface of the gear. (2) A stator including a rotor having an annular or disk-shaped permanent magnet magnetized with multiple poles, a stator winding arranged opposite to the rotor, and a magnetic flux shielding member that shields a portion of leakage magnetic flux and has a plurality of reflecting parts having different light reflectances at equal intervals; and a light emitting light receiving element disposed at a position facing the reflecting part of the magnetic flux shielding member. A motor characterized by comprising: (3) A stator including a rotor having an annular or disc-shaped permanent magnet magnetized to multiple poles, a stator winding arranged opposite to the rotor, and a magnetic flux shielding member that shields a portion of leakage magnetic flux and has a plurality of reflecting parts having different light reflectances at equal intervals; and a light emitting light receiving element disposed at a position facing the reflecting part of the magnetic flux shielding member. A motor characterized in that the shielding area of the magnetic flux shielding member is provided at every boundary area between the N pole and the S pole of the permanent magnet of the rotor.