JP7325946B2 - Motors and rotating equipment - Google Patents

Description

The present invention relates to motors and rotating equipment.

Conventionally, a magnetic sensor using a Hall element or the like has been used to detect the state of rotation for motor control. The magnetic sensor detects the magnetic flux of a magnet attached to the rotor of the motor and outputs a signal corresponding to the rotational state of the motor.

On the other hand, a reflecting surface is attached on the concentric circle of the multipolar magnet so that the light emitted from the light emitting element is reflected and enters the light receiving element. An electric motor is disclosed in which a light emitting element and a light receiving element are arranged on a surface having a reflecting surface (see, for example, Patent Document 1).

JP-A-62-2845

However, when a magnetic sensor is used, for example, when the temperature of the rotor magnet becomes high, the magnetic flux density decreases, and it may be difficult for the magnetic sensor to detect the magnetic flux of the rotor magnet. Further, when a Hall element is used in the magnetic sensor, the performance of the Hall element changes when the ambient temperature is high, and a desired signal cannot be obtained from the Hall element, making it difficult to detect the position of the rotor magnet. may become.

If the distance between the rotor magnet and the magnetic sensor is too close, they may contact each other, so it is necessary to separate them to some extent. If the distance is long, it may be difficult for the magnetic sensor to detect the magnetic flux of the rotor magnet. be. As a result, a deviation may occur between the rotation angle of the rotor detected by the magnetic sensor and the actual rotation angle of the rotor.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a motor capable of improving the detection accuracy of a rotation angle.

A motor according to an aspect of the present invention includes a shaft, a rotor supported by the shaft, a stator provided inside the rotor, a member facing the rotor in the axial direction of the shaft , and and a sensor provided on the member . The sensor also has a light source that emits light in the radial direction and a light receiving portion that receives the light from the light source in the radial direction . The rotor includes a light blocking portion projecting in the axial direction, a magnetic member having a cylindrical portion and a top surface portion, and a magnet fixed to the cylindrical portion of the magnetic member. The sensors are arranged at positions sandwiching the light shielding portion in the radial direction. Axially, the magnet faces the sensor. In the rotating state of the rotor , light directed from the light source to the light receiving section is blocked by the light blocking section.

A motor according to an aspect of the present invention can improve the detection accuracy of a rotation angle.

FIG. 1 is an external perspective view of the motor according to the first embodiment. FIG. 2 is a longitudinal sectional view of the motor in the first embodiment. FIG. 3 is a perspective view of elements around the sensor in the first embodiment. FIG. 4 is a diagram showing how the rotor yoke is attached in the first embodiment. FIG. 5 is a view of the rotor yoke in the first embodiment viewed from another viewpoint. FIG. 6 is an external perspective view of the motor according to the second embodiment. FIG. 7 is a longitudinal sectional view of the motor in the second embodiment. FIG. 8 is a diagram showing how the rotor yoke is attached in the second embodiment. FIG. 9 is a view of the rotor yoke in the second embodiment viewed from another viewpoint. FIG. 10 is an external perspective view of a rotating device according to the third embodiment. FIG. 11 is a perspective view showing exploded components of a rotating device according to the third embodiment.

Hereinafter, motors according to embodiments will be described with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, the dimensional relationship of each element in the drawings, the ratio of each element, and the like may differ from reality. Even between the drawings, there are cases where portions with different dimensional relationships and ratios are included. In addition, the contents described in one embodiment and modification are in principle similarly applied to other embodiments and modifications.

(First embodiment)
FIG. 1 is an external perspective view of a motor 100 according to the first embodiment, which is an example of an inner rotor type motor in which a rotor is provided inside the motor. In FIG. 1, motor 100 includes housing 118 and shaft 104 . The housing 118 includes a cylindrical tubular portion 101 having a bottom portion on the upper side in the drawing (one end side of the shaft 104), and an opening on the lower side in the drawing (the other end side of the shaft 104) of the cylindrical portion 101. It consists of a lid (102) that is not visible in FIG. The shaft 104 is rod-shaped and is exposed from the center of a convex portion 101a provided at the center of the upper end face of the cylindrical portion 101 in the figure. A wiring portion 101c provided on the outer peripheral surface (side surface) of the cylindrical portion 101 is connected to a power supply line (not shown).

FIG. 2 is a longitudinal sectional view of the motor 100 in the first embodiment. In FIG. 2, a lid portion 102 is fixed to cover the opening on the lower side of the cylindrical portion 101 in the figure. Lid portion 102 is an example of a base.

A tubular rotor yoke 105 made of a magnetic material is fixed (fitted) to the outer peripheral surface of the shaft 104 . A ring-shaped magnet 106 is fixed (fitted) to the outer peripheral surface of the rotor yoke 105 . A rotor 103 is composed of the shaft 104 , the rotor yoke 105 and the magnet 106 . The rotor yoke 105 is an example of a magnetic member.

The shaft 104 has an inner ring of a bearing 107 whose outer ring is fitted to the inner surface (inner wall) of the convex portion 101 a of the cylindrical portion 101 and an outer ring fixed (fitted) to the inner surface (inner wall) of the convex portion 102 a of the lid portion 102 . It is rotatably supported by the inner ring of bearing 108 . A hole portion 101b through which the shaft 104 penetrates is formed in the center portion of the convex portion 101a in the radial direction. A hole portion 102b is formed in the central portion of the convex portion 102a in the radial direction.

A core 112 , a first insulator 113 and a second insulator 114 , and a coil 115 are provided on the inner surface (inner wall) of the cylindrical portion 101 . The core 112 is formed by laminating electromagnetic steel sheets. First insulator 113 and second insulator 114 sandwich core 112 from both sides in the axial direction. Coil 115 is wound around the outer peripheral surfaces of first insulator 113 and second insulator 114 . The inner peripheral surface of core 112 faces the outer peripheral surface of magnet 106 of rotor 103 with a gap therebetween. Stator 111 is configured by core 112 , first insulator 113 , second insulator 114 , and coil 115 .

Between the cover portion 102 and the rotor 103 in the axial direction of the shaft 104 is fixed a substrate 116 on which electronic components such as resistance elements and capacitors and circuits composed of these electronic components are provided. A sensor 117 is provided on the substrate 116 . The sensor 117 is arranged at a position that sandwiches a light shielding portion (light shielding piece) 105a provided at the end of the rotor yoke 105 in the radial direction. The sensor 117 includes a light source that emits light in the radial direction of the rotor 103 and a light receiving portion that receives light from the light source. That is, the sensor 117 has a substantially U-shaped cross-section that is laid down sideways, and one of the inner surfaces 117a and 117b on both sides facing upward in the figure is on the light source side, and the other is on the light receiving part side. It has become. Either of the inner surfaces 117a and 117b may be on the light source side. The light shielding portion 105a can be formed integrally with the rotor yoke 105, which is a magnetic member, which facilitates manufacturing. Since the sensor 117 is provided on the substrate 116 between the lid portion 102 and the rotor 103, the size of the motor does not increase. Substrate 116 is an example of a member. The light shielding portion 105a is an example of a light shielding portion or a convex portion.

FIG. 3 is a perspective view of extracted elements around the sensor 117 in the first embodiment. In FIG. 3, at the end of the rotor yoke 105 fitted to the shaft 104 on the substrate 116 side, light shielding portions 105a extending in the axial direction are provided at regular intervals. Wiring pins (not shown) are attached to the plurality of holes 116 a on the substrate 116 .

FIG. 4 is a diagram showing how the rotor yoke 105 is attached in the first embodiment. FIG. 4 shows the state before the rotor yoke 105 is fixed (fitted) to the shaft 104 . FIG. 5 is a view of the rotor yoke 105 in the first embodiment viewed from another viewpoint. In the illustrated example, a total of four light shielding portions 105a are provided at the end portion of the rotor yoke 105, but the number of light shielding portions 105a is not limited to this, and may be one. Moreover, when there are a plurality of light shielding portions 105a, the circumferential lengths of the light shielding portions 105a may not be equal, and the circumferential intervals between adjacent light shielding portions 105a may not be equal.

Instead of the light-shielding portion 105a, a tube (cylinder) made of a transparent member is provided at the end of the rotor yoke 105, and a light-shielding portion is provided by a light-shielding surface by coloring or forming a light-shielding film on the transparent tube. may be made available. The number of light-shielding portions formed by the light-shielding surface is arbitrary, and the circumferential length between the light-shielding portions of the light-shielding surface may not be equal, and the circumferential intervals between the adjacent light-shielding portions may also be unequal.

1 to 5, the rotation of the rotor 103 causes the light blocking portion 105a to pass between the light source and the light receiving portion of the sensor 117, thereby intermittently blocking the light from the sensor 117. A signal indicating the rotation state of the rotor 103 is obtained and used for speed control. be done. In this way, it is possible to improve the detection accuracy of the rotation angle with a simple configuration. In addition, compared with the conventional magnetic sensor using a Hall element or the like, there is an advantage that stable detection can be performed because it is not affected by the temperature of the magnet or the distance between the magnet and the sensor. In addition, compared with the case of using a reflecting surface on a magnet, a light emitting element, and a light receiving element, there is an advantage that detection can be performed stably because it is not affected by vibration of the magnet.

In order to avoid erroneous detection due to dirt or the like adhering to the sensor 117, the light shielding portion 105a, or the light shielding surface, the signal from the sensor 117 changes from the state in which the light from the light source is blocked to the state in which the light is released. It is desirable to detect the rotation state from the change in . This is because the state in which the light from the light source is blocked includes the case where the light is not blocked by the true light blocking portion 105a but by dirt or the like, whereas the state in which the light is unblocked is not affected by dirt or the like. It is from.

(Second embodiment)
FIG. 6 is an external perspective view of a motor 200 according to the second embodiment, which is an example of an outer rotor type motor in which a rotor is provided outside the motor. In FIG. 6, motor 200 comprises rotor yoke 204 , substrate 207 and plate 206 . The rotor yoke 204 is cup-shaped and fixed to the shaft 202 via the hub 203 . The substrate 207 is provided with a circuit and a sensor 216 . The sensor 216 is arranged at a position sandwiching a light shielding portion (light shielding piece) 204 a provided at the end of the rotor yoke 204 . The sensor 216 includes a light source that emits light radially and a light receiving portion that receives the light from the light source. The plate 206 is fixed to a sleeve (208), described later, that rotatably supports the rotor yoke 204. As shown in FIG.

FIG. 7 is a longitudinal sectional view of motor 200 in the second embodiment. In FIG. 7, a hub 203 is fitted to a rod-shaped shaft 202, and a cup-shaped rotor yoke 204 made of a magnetic material is fixed to the hub 203. As shown in FIG. The rotor yoke 204 has a tubular portion and a top portion (annular flat plate portion) facing the stator 211 in the axial direction. A ring-shaped magnet 205 is fixed to the inner wall surface (inner surface) of the outer peripheral portion of the rotor yoke 204 . A rotor 201 is composed of the shaft 202 , the hub 203 , the rotor yoke 204 and the magnets 205 .

The shaft 202 is rotatably supported by bearings 209 and 210 fixed (fitted) to the inner surface of a sleeve 208 (also referred to as a bearing housing). The sleeve 208 is cylindrical and has one end fixed to the plate 206 . Between the axial end of hub 203 and the inner ring of bearing 209, the small diameter end of tapered spring 217 is mounted on bearing 209. As shown in FIG. With these configurations, the bearings 209 and 210 are pressurized or preloaded, and the position of the end portion of the light shielding portion 204a on the sensor 216 side is stabilized, thereby improving the detection accuracy.

A core 212 , a first insulator 213 and a second insulator 214 , and a coil 215 are provided on the outer peripheral surface of the sleeve 208 . The core 212 is formed by laminating electromagnetic steel sheets. First insulator 213 and second insulator 214 sandwich core 212 from both sides in the axial direction. Coil 215 is wound around the outer peripheral surfaces of first insulator 213 and second insulator 214 . The outer peripheral surface of core 212 faces the inner peripheral surface of magnet 205 of rotor 201 with a gap therebetween. Stator 211 is configured by core 212 , first insulator 213 , second insulator 214 , and coil 215 .

A substrate 207 provided with a circuit is fixed between the plate 206 and the rotor 201 in the axial direction of the shaft 202 . A sensor 216 is provided on the substrate 207 . The sensor 216 is arranged at a position that sandwiches a light shielding portion (light shielding piece) 204a provided at the end of the rotor yoke 204 in the radial direction. The sensor 216 includes a light source that emits light in the radial direction of the rotor 201 and a light receiving portion that receives light from the light source. That is, the sensor 216 has a substantially U-shaped cross-section that is laid down sideways, and one of the inner surfaces 216a and 216b on both sides facing upward in the figure is the light source side, and the other is the light receiving part side. It has become. Either of the inner surfaces 216a and 216b may be on the light source side. The light shielding portion 204a can be configured integrally with the rotor yoke 204, which is a magnetic member, which facilitates manufacturing. Since the sensor 216 is provided on the substrate 207 between the plate 206 and the rotor 201, the size of the motor does not increase. The substrate 207 is an example of a member. The light shielding portion 204a is an example of a light shielding portion or a convex portion.

FIG. 8 is a diagram showing how the rotor yoke 204 is attached in the second embodiment. FIG. 8 shows the state before the rotor yoke 204 is fixed (fitted) to the hub 203 . A sensor 216 is provided on the substrate 207 . At the end of the rotor yoke 204 on the side of the substrate 207, light blocking portions 204a extending in the axial direction are provided at regular intervals. FIG. 9 is a view of the rotor yoke 204 in the second embodiment viewed from another viewpoint. In the illustrated example, a total of four light shielding portions 204a are provided at the end portion of the rotor yoke 204, but the number of light shielding portions 204a is not limited to this, and may be one. Moreover, when there are a plurality of light shielding portions 204a, the circumferential lengths of the light shielding portions 204a may not be equal, and the circumferential intervals between adjacent light shielding portions 204a may not be equal.

Instead of the light shielding portion 204a, a tube (cylinder) made of a transparent member may be provided at the end of the rotor yoke 204, and the transparent tube may be provided with a light shielding surface by coloring or the like. The number of light-shielding portions formed by the light-shielding surface is arbitrary, and the length of the light-shielding portions formed by the light-shielding surface in the circumferential direction may not be equal, and the intervals between adjacent light-shielding portions in the circumferential direction may not be equal.

6 to 9, the rotation of the rotor 201 causes the light blocking portion 204a to pass between the light source and the light receiving portion of the sensor 216, intermittently blocking the light from the sensor 216. A signal indicating the rotation state of the rotor 201 is obtained and used for speed control. be done. In this way, it is possible to improve the detection accuracy of the rotation angle with a simple configuration. In addition, compared with the conventional magnetic sensor using a Hall element or the like, there is an advantage that stable detection can be performed because it is not affected by the temperature of the magnet or the distance between the magnet and the sensor. In addition, compared with the case of using a reflecting surface on a magnet, a light emitting element, and a light receiving element, there is an advantage that detection can be performed stably because it is not affected by vibration of the magnet.

In order to avoid erroneous detection due to dirt or the like adhering to the sensor 216, the light shielding portion 204a, or the light shielding surface, the signal from the sensor 216 changes from the state in which the light from the light source is blocked to the state in which the light is released. It is desirable to detect the rotation state from the change in . This includes the case where the light from the light source is shielded not by the true light shielding portion 204a but by dirt or the like. It is from.

(Third embodiment)
FIG. 10 is an external perspective view of a rotating device 300 according to the third embodiment, showing an example in which the rotating device 300 is a blower fan. In FIG. 10, the rotating device 300 includes a cover 304, a blower port frame 305, and an impeller 303 as parts that can be seen from the outside. That is, the impeller 303 is provided inside the cover 304 , and air is blown from inside the blower port frame 305 .

FIG. 11 is a perspective view showing exploded components of the rotating device 300 according to the third embodiment. In FIG. 11 , rotating device 300 includes plate 301 , motor 200 , impeller 303 , cover 304 , and blower port frame 305 . That is, the motor 200 is fixed to the hole 301 a of the plate-like plate 301 , and the impeller 303 is fixed to the rotor yoke 204 of the motor 200 . Also, the blower port frame 305 is fixed to the cover 304 , and the cover 304 is fixed to the plate 301 with a plurality of screws 302 . Motor 200 is an outer type motor shown in FIGS.

As shown in FIG. 7 and the like, the motor 200 has a function of simply detecting the rotation state by the light shielding portion 204a and the sensor 216, so that the rotation state of the motor 200 in the rotating device 300 can be accurately detected. It is possible to appropriately control the blowing state.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

As described above, the motor according to the embodiment includes a shaft, a rotor supported by the shaft, a member facing the rotor in the axial direction of the shaft, and a sensor provided on the member. , a light source that emits light in a radial direction, and a light receiving portion that receives light from the light source. Light directed toward the portion is blocked by the light blocking portion. Accordingly, it is possible to provide a motor capable of improving the detection accuracy of the rotation angle.

Also, the light shielding portion is a convex portion protruding in the axial direction at the end portion of the rotor. As a result, it is possible to improve the detection accuracy of the rotation angle with a simple configuration.

Also, the light shielding portion is a light shielding surface formed on a transparent member at the end of the rotor. As a result, it is possible to improve the detection accuracy of the rotation angle with a simple configuration.

In addition, a light blocking portion and a lighting portion may be provided at the end of the rotor yoke 105 in the circumferential direction. In the above-described embodiments, the lighting portion corresponds to the gap formed between the plurality of light shielding portions in the circumferential direction.

Moreover, in the circumferential direction, the light shielding portion may be longer than the lighting portion, and the lighting portion may be longer than the light shielding portion. In the circumferential direction, the sum of the lengths of the plurality of light shielding portions may be greater than the sum of the lengths of the plurality of lighting portions. It may be greater than the sum of the lengths of the parts.

Further, the rotor has a cylindrical magnetic member, and the light blocking portion is formed on the magnetic member. As a result, the light shielding portion can be formed integrally with the magnetic member of the rotor, which facilitates manufacturing.

Further, the rotor yoke is not limited to being made of a magnetic member, and may be made of a non-magnetic member such as a resin member.

It also has a base and a bearing that rotatably supports the shaft. The shaft is supported by the base via the bearing, and the member is formed between the base and the rotor in the axial direction. As a result, it is not necessary to increase the size of the motor.

A ring-shaped seat (spring seat) 109 may be fixed (fitted) to the shaft 104 in contact with the inner ring of the bearing 108 . A spring 110 may be provided between the pedestal 109 and the end surface of the rotor yoke 105 . By providing these configurations as necessary, pressure or preload may be applied to the bearings 107 and 108 to stabilize the position of the end portion of the light shielding portion 105a on the sensor 117 side and improve the detection accuracy. . Note that the spring 110 is an example of an elastic member.

Further, the base, a bearing that rotatably supports the shaft, and an elastic member that is arranged between the bearing and the rotor or between the bearing and the base and is elastically compressible in the axial direction may be provided. . As a result, an appropriate pressurization or preload is applied to the bearing, and the position of the sensor-side end of the light shielding portion is stabilized, thereby increasing the detection accuracy.

Further, the rotation state is detected from the change from the state in which the light from the light source is blocked to the state in which the light from the light source is released, among the signals from the sensor. As a result, erroneous detection due to adhesion of dirt or the like can be avoided.

Further, a stator surrounding the rotor is provided, and a light shielding portion is provided on the outer peripheral portion of the rotor. As a result, it can be easily applied to an inner rotor type motor.

A stator is provided inside the rotor, and a light shielding portion is provided on the outer peripheral portion of the rotor. Accordingly, it can be easily applied to an outer rotor type motor.

Further, instead of the tapered spring provided between the axial end of the hub and the inner ring of the bearing, a cylindrical spring may be provided.

Also, the rotating device includes the motor described above and an impeller fixed to the shaft. As a result, the rotational state of the motor of the rotating device can be accurately detected and properly controlled.

Moreover, the present invention is not limited by the above embodiments. The present invention also includes those configured by appropriately combining each of the constituent elements described above. Further effects and modifications can be easily derived by those skilled in the art. Therefore, broader aspects of the present invention are not limited to the above-described embodiments, and various modifications are possible.

Reference Signs List 100, 200 motor 103, 201 rotor 104, 202 shaft 105, 204 rotor yoke 105a, 204a light shielding portion 106, 205 magnet 107, 108, 209, 210 bearing 110, 217 spring 111, 211 stator, 116, 207 substrate, 117, 216 sensor

Claims (5)

a shaft;
a rotor journalled on the shaft;
a stator provided inside the rotor;
a member facing the rotor in the axial direction of the shaft;
a sensor provided on the member;
with
The sensor is
a light source that emits light radially;
a light receiving portion that receives light from the light source in a radial direction ;
has
The rotor includes a light blocking portion protruding in the axial direction, a magnetic member having a cylindrical portion and a top surface portion, and a magnet fixed to the cylindrical portion of the magnetic member,
The sensor is arranged at a position sandwiching the light shielding part in a radial direction,
the magnet faces the sensor in the axial direction,
In a rotating state of the rotor, light directed from the light source to the light receiving unit is blocked by the light blocking unit.
motor. a base;
a bearing that rotatably supports the shaft;
with
the shaft is supported by the base via the bearing;
the member is axially formed between the base and the rotor;
A motor according to claim 1 . a base;
a bearing that rotatably supports the shaft;
an elastic member that is axially elastically compressible and disposed between the bearing and the rotor or between the bearing and the base;
comprising
A motor according to claim 1 or 2 . Among the signals of the sensor, the rotation state is detected from a change from a state in which the light from the light source is blocked to a state in which the light is released.
The motor according to any one of claims 1-3 . The motor according to any one of claims 1 to 4 ;
an impeller fixed to the shaft;
rotating equipment.

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