JP6842838B2 - Motors, in-wheel motors and wheel devices - Google Patents

Description

The present invention relates to motors, in-wheel motors and wheel devices.

Conventionally, a motor used for driving various devices or various devices is generally provided with an angle sensor for controlling the operation of the motor. The angle sensor detects the relative rotation angle between the stator and rotor contained in the motor. For example, as the angle sensor, an optical encoder, a resolver, or the like is used. In recent years, since the devices using motors have been diversified, there is a demand for a miniaturized motor having a built-in angle sensor.

Japanese Unexamined Patent Publication No. 2015-89188 Patent No. 5615033 Patent No. 5517869

However, it has been difficult to incorporate the above-mentioned conventional angle sensor into a small motor. For example, it is difficult to incorporate an optical encoder into a motor due to problems with heat resistance and shape. Further, since the resolver has a structure using a coil or the like, it is difficult to miniaturize it, and it is difficult to incorporate it in a small motor. For these reasons, it has been difficult to realize a miniaturized motor while incorporating an angle sensor in the motor by the conventional technology.

The present invention has been made in view of the above, and an object of the present invention is to provide a motor, an in-wheel motor, and a wheel device that can be miniaturized while incorporating an angle sensor.

In order to solve the above-mentioned problems and achieve the object, the motor according to one aspect of the present invention includes a stator, a rotor that rotates relative to the stator about a rotation shaft, and a shaft of the rotation shaft. A shaft arranged so as to extend in the direction and an angle sensor for detecting the rotation angle of the rotor with respect to the stator are provided, and the rotor includes a peripheral wall surrounding the outer periphery of the stator and an end of the shaft in the axial direction. The shaft is fixed to the stator and is arranged so as to face the rotor at a predetermined distance in the axial direction so as to face the rotor and have a bottom having a sensor magnet. , At the axial end of the shaft, located at a portion of the rotor facing the sensor magnet provided at the bottom of the rotor. The entire surface of the angle sensor and the entire surface of the sensor magnet face each other directly with a predetermined interval without interposing other members.

According to one aspect of the present invention, it is possible to realize a motor and an in-wheel motor that can be miniaturized while incorporating an angle sensor.

FIG. 1 is a perspective view showing the appearance of a wheel device incorporating an in-wheel motor according to the present embodiment. FIG. 2 is an exploded perspective view showing a configuration of a wheel device incorporating an in-wheel motor according to the present embodiment. FIG. 3 is an exploded cross-sectional perspective view showing the configuration of a wheel device incorporating an in-wheel motor according to the present embodiment. FIG. 4 is a cross-sectional perspective view showing a configuration of a stator included in the in-wheel motor according to the present embodiment. FIG. 5 is an exploded perspective view showing a configuration of a rotor included in the in-wheel motor according to the present embodiment. FIG. 6 is a front view showing a wheel device according to the present embodiment. FIG. 7 is a side sectional view showing a wheel device according to the present embodiment.

Hereinafter, the motor, the in-wheel motor, and the wheel device according to the embodiment will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a perspective view showing the appearance of a wheel device incorporating an in-wheel motor according to the present embodiment. The in-wheel motor according to the present embodiment is built in, for example, the wheel device 100 shown in FIG. The wheel device 100 is used, for example, as a drive wheel for a self-propelled robot, a transport carriage, or the like.

For example, as shown in FIG. 1, the wheel device 100 includes a wheel 110 and a tire 120. The wheel 110 is a wheel formed in a substantially bottomed cylindrical shape using metal, plastic, or the like. The tire 120 is formed in a substantially annular shape using an elastic material such as rubber, and is fixed so as to surround the wheel 110. For example, since the tire 120 is a consumable item, the wheel 110 and the tire 120 have a structure in which they can be exchanged in an integrated state with each as a basic configuration.

For example, the in-wheel motor according to the present embodiment is directly connected to the wheel 110 and rotates the wheel 110 around a predetermined rotation axis R. That is, the in-wheel motor according to the present embodiment is, for example, a direct drive type in-wheel motor.

FIG. 2 is an exploded perspective view showing the configuration of the wheel device 100 incorporating the in-wheel motor according to the present embodiment. For example, as shown in FIG. 2, the in-wheel motor 200 according to the present embodiment is mounted inside the wheel 110 of the wheel device 100 and is fixed to the bottom of the wheel 110 by a nut 111.

For example, the in-wheel motor 200 includes a stator 210, a rotor 220, and a cover 230. The stator 210 is fixed to the device on which the wheel device 100 is mounted via a shaft 211 arranged so as to extend in the axial direction of the rotation shaft R.

The rotor 220 rotates relative to the stator 210 about the rotation axis R. Here, the rotor 220 has a housing 221 for accommodating the stator 210, is arranged so as to surround the outer circumference of the stator 210, and rotates along the outer circumference. That is, the in-wheel motor 200 according to the present embodiment is an outer rotor type motor.

The cover 230 has a through hole 231 formed therein, and the space inside the housing 221 of the rotor 220 is sealed in a state where the shaft 211 is passed through the through hole 231. For example, the cover 230 is formed in a substantially disk shape, and a through hole 231 is provided substantially in the center. Then, the cover 230 is fixed to the wheel 110 by, for example, a screw 232 in a state where the stator 210 is housed in the housing 221 and the shaft 211 is passed through the through hole 231.

Here, the stator 210, the rotor 220, and the in-wheel motor 200 have a waterproof structure that prevents water from entering the housing 221 of the rotor 220. For example, the cover 230 includes an O-ring 233 and a rubber seal bearing 234. The O-ring 233 is arranged between the cover 230 and the housing 221 of the rotor 220, and seals between the two. The rubber seal bearing 234 rotatably supports the shaft 211 inside the through hole 231 of the cover 230 and seals between the through hole 231 and the shaft 211. Further, the screw 232 that fixes the cover 230 to the wheel 110 is waterproofed after being tightened.

FIG. 3 is an exploded cross-sectional perspective view showing the configuration of the wheel device 100 incorporating the in-wheel motor 200 according to the present embodiment. For example, as shown in FIG. 3, the in-wheel motor 200 includes an angle sensor 212 that detects the rotation angle of the rotor 220 with respect to the stator 210. Here, the angle sensor 212 is arranged between an axial end of the shaft 211 and a portion of the rotor 220 that faces the end.

In the present embodiment, the angle sensor 212 is a magnetic sensor, and detects the rotation angle of the rotor 220 with respect to the stator 210 by detecting the angular position of the sensor magnet 222 provided on the stator 210 and provided on the rotor 220. To do. For example, the angle sensor 212 includes an IC (Integrated Circuit), detects the angular position of a magnet placed at a position facing the IC by an absolute angle or a relative angle, and outputs a control signal of three phases of the UVW phase. A high-speed rotation angle sensor capable of output is used.

FIG. 4 is a cross-sectional perspective view showing the configuration of the stator 210 included in the in-wheel motor 200 according to the present embodiment. For example, as shown in FIG. 4, the stator 210 includes a shaft 211, an angle sensor 212, a stator base 213, a bearing 214, a stator core 215, and a substrate 216.

The stator base 213 is a support member arranged substantially in the center of the stator 210, and is formed in a substantially bottomed cylindrical shape. Here, the stator base 213 is arranged so that the central axis of the stator base 213 coincides with the rotation axis R.

The shaft 211 is formed in a hollow substantially cylindrical shape, and is fixed in a state where one end thereof is inserted into the inner peripheral side of the stator base 213. Here, the shaft 211 is fixed to the stator base 213 so that the central axis of the shaft 211 coincides with the central axis of the stator base 213.

The bearing 214 is fixed at a position separated from the outer bottom surface of the stator base 213 by a predetermined distance. Here, the bearing 214 is fixed to the stator base 213 so that the central axis of the bearing 214 coincides with the central axes of the stator base 213 and the shaft 211, respectively.

The stator core 215 has a laminated structure in which a plurality of plate-shaped soft magnetic materials are laminated in the axial direction of the stator base 213, and is fixed to the outer periphery of the stator base 213 and the outer periphery side of the bearing 214. Here, a plurality of salient poles (not shown) are provided on the outer peripheral portion of the stator core 215 at substantially equal intervals along the circumferential direction. A coil is wound around each salient pole.

The substrate 216 is formed in a substantially disk shape and is fixed so as to be orthogonal to the central axis of the stator base 213. Here, the substrate 216 is arranged at a predetermined interval in the axial direction along the end surface of the stator core 215 on the side where the shaft 211 protrudes.

Then, in the present embodiment, the angle sensor 212 is fixed to the outer bottom surface of the stator base 213 so as to intersect the central axis of the stator base 213. As a result, the angle sensor 212 is arranged at a position facing the bearing hole of the bearing 214.

Further, in the present embodiment, the stator 210 further includes another angle sensor 217 that detects the rotation angle of the rotor 220 with respect to the stator 210, in addition to the angle sensor 212 described above. For example, as the angle sensor 217, an angle sensor using a Hall element or a Hall IC is used.

For example, three angle sensors 217 are provided on the surface of the substrate 216 facing the stator core 215 with positions shifted by 120 ° in the circumferential direction. In FIG. 4, two of the three angle sensors 217 are not shown.

In this way, it is possible to have a redundant configuration in which a plurality of angle sensors are provided.

FIG. 5 is an exploded perspective view showing a configuration of a rotor 220 included in the in-wheel motor 200 according to the present embodiment. For example, as shown in FIG. 5, the rotor 220 includes a housing 221 and a plurality of magnets 223.

The housing 221 is formed in a substantially bottomed cylindrical shape, and includes a rotor frame 221a as a peripheral wall and a rotor case 221b as a bottom. The rotor frame 221a is formed in a substantially cylindrical shape using a non-magnetic material. The rotor case 221b is formed in a substantially disk shape using a non-magnetic material. The rotor case 221b is provided with a plurality of protrusions 221c that are arranged in a comb-teeth shape in the circumferential direction along the end portions and project toward the side facing the rotor frame 221a.

Each of the plurality of magnets 223 has a strip-shaped shape, and is provided in a magnetized state along the inner circumference of the rotor frame 221a at substantially equal intervals in the circumferential direction. When the rotor case 221b is attached to the rotor frame 221a, these magnets 223 are positioned in the circumferential direction of the rotor frame 221a by fitting the protrusions 221c of the rotor case 221b into the gaps between the magnets 223. It is fixed.

Further, these magnets 223 are arranged so as to face the stator core 215 when the stator 210 is incorporated inside the rotor 220. As a result, when a drive current is passed through the coil of the stator core 215, the rotor 220 rotates around the rotation axis R along the outer circumference of the stator 210 due to the electromagnetic force generated in the coil.

Then, in the present embodiment, the rotor case 221b is provided with a rod-shaped rotor shaft 221d that projects along the rotation shaft R toward the side facing the rotor frame 221a. Here, the sensor magnet 222 described above is fixed to the tip portion of the rotor shaft 221d. The rotor shaft 221d is arranged so as to penetrate the bearing hole of the bearing 214 provided in the stator 210 when the stator 210 is incorporated inside the rotor 220. As a result, the sensor magnet 222 fixed to the tip of the rotor shaft 221d is arranged so as to face the angle sensor 212.

FIG. 6 is a front view showing the wheel device 100 according to the present embodiment, and FIG. 7 is a side sectional view showing the wheel device 100 according to the present embodiment. Note that FIG. 7 shows a cross section of the wheel device 100 shown in FIG. 6 at positions AA.

For example, as shown in FIG. 7, in the present embodiment, the shaft 211 is fixed to the stator 210 and is arranged so as to face the rotor 220 at a predetermined distance D in the axial direction. Then, the angle sensor 212 is arranged between the axial end portion of the shaft 211 and the portion of the stator 210 facing the end portion.

Specifically, the stator 210 and the rotor 220 are arranged so that the end portion of the shaft 211 on the stator 210 side in the axial direction and the tip end portion of the rotor shaft 221d are arranged so as to be separated by a distance D. An angle sensor 212 is provided at the end of the shaft 211 on the stator 210 side in the axial direction, and a sensor magnet 222 is provided at the tip of the rotor shaft 221d.

Here, the distance D is a distance according to the specifications of the angle sensor 212. For example, when a magnetic sensor is used as the angle sensor 212 as in the present embodiment, the distance D is set so that the sensor magnet 222 is arranged within a range in which the rotation angle can be detected by the angle sensor 212. Will be done.

By arranging the axial end of the shaft 211 and the rotor 220 at a predetermined distance D in this way, a space for arranging the angle sensor 212 is secured inside the in-wheel motor 200. be able to. As a result, the angle sensor 212 can be incorporated in the in-wheel motor 200 without increasing the width in the axial direction of the in-wheel motor 200 (the stacking direction of the stator cores 215). In the present embodiment, it is possible to realize an in-wheel motor that can be miniaturized while incorporating an angle sensor by the configuration related to the arrangement of the magnetic sensor.

Further, in the present embodiment, the in-wheel motor 200 is connected to the lead wire 241 connected to the stator 210 arranged in the space inside the housing 221, the lead wire 242 connected to the angle sensor 212, and the angle sensor 217. It is provided with a lead wire 243.

Here, the lead wire 241 is a feeder line that supplies a drive current to the coil of the stator 210 from an external power supply device. Further, the lead wire 242 is a signal line for transmitting a control signal output from the angle sensor 212 to an external control device. Further, the lead wire 243 is a signal line for transmitting a control signal output from the angle sensor 217 to an external control device.

Then, the lead wires 241 to 243 are wired from the space inside the housing 221 through the inside of the shaft 211 to the outside of the cover 230. For example, each lead wire is wired through a through hole 211a provided in a part of the peripheral wall portion of the shaft 211. Here, the through hole 211a is arranged between the stator core 215 and the cover 230 when the stator 210 is incorporated in the housing 221 and the cover 230 is attached to the housing 221 in the shaft 211. It is provided at the position.

By wiring each lead wire through the inside of the shaft 211 in this way, each lead wire is connected from the inside to the outside of the in-wheel motor 200 while the space inside the housing 221 is kept sealed by the cover 230. It becomes possible to wire.

As described above, according to the present embodiment, it is possible to realize an in-wheel motor capable of miniaturization while incorporating an angle sensor.

In the above-described embodiment, an example in which the in-wheel motor 200 includes three angle sensors 217 in addition to the angle sensor 212 has been described, but the embodiment is not limited to this. For example, when the angle sensor 212 is sufficient as the sensor for angle detection, the substrate 216 and the three angle sensors 217 may be excluded from the components of the in-wheel motor 200. In this case, the width of the stator 210 in the axial direction can be further shortened by the amount excluding the substrate 216 and the three angle sensors 217, so that the in-wheel motor 200 can be further miniaturized.

Further, in the above-described embodiment, the in-wheel motor has been described, but the embodiment is not limited to this. The above-mentioned configuration regarding the arrangement of the angle sensor is also applicable to other types of motors having a stator and a rotor.

Further, in the above-described embodiment, the outer rotor type motor has been described, but the embodiment is not limited to this. For example, the above-mentioned configuration regarding the arrangement of the angle sensor can be applied to the inner rotor type motor and the axial gap type motor.

For example, the inner rotor type motor includes a stator and a rotor arranged on the inner peripheral side of the stator and rotating along the inner peripheral circumference of the stator. In this case, for example, the shaft is fixed to the rotor and is arranged so as to face the stator at a predetermined distance in the axial direction. Then, the angle sensor is arranged between the axial end portion of the shaft and the portion of the stator facing the end portion.

Further, for example, an axial gap type motor includes a stator and a rotor arranged so as to face each other in the axial direction of the rotating shaft. In this case, for example, the shaft is fixed to one of the stator and the rotor, and is arranged so as to face the other of the stator and the rotor at a predetermined distance in the axial direction. The angle sensor is then arranged between the axial end of the shaft and the other end of the stator and rotor that faces the end.

In any type of motor, an angle sensor is placed inside the motor by arranging the axial end of the shaft and the portion of the stator or rotor facing the end by a predetermined distance. It is possible to secure a space for doing so. This makes it possible for any type of motor to have an angle sensor built into the motor without increasing the axial width of the motor. That is, it is possible to realize a motor that can be miniaturized while incorporating an angle sensor.

Moreover, the present invention is not limited by the above-described embodiment. The present invention also includes a configuration in which the above-mentioned constituent elements are appropriately combined. Further, further effects and modifications can be easily derived by those skilled in the art. Therefore, the broader aspect of the present invention is not limited to the above-described embodiment, and various modifications can be made.

110 Wheel 200 In-Wheel Motor 210 Stator 211 Shaft 212 Angle Sensor 217 Angle Sensor 220 Rotor 221 Housing 222 Sensor Magnet 230 Cover 241-243 Lead Wire

Claims (7)

With the stator
A rotor that rotates relative to the stator about the rotation axis,
A shaft arranged so as to extend in the axial direction of the rotating shaft,
It is provided with an angle sensor that detects the rotation angle of the rotor with respect to the stator.
The rotor includes a peripheral wall surrounding the outer periphery of the stator and a bottom portion that faces the end of the shaft in the axial direction and has a magnet for a sensor.
The shaft is fixed to the stator and is arranged so as to face the rotor at a predetermined distance in the axial direction.
The angle sensor is arranged at a portion of the shaft at the axial end that faces the sensor magnet provided at the bottom of the rotor .
The entire angle sensor entire face of the surface of the sensor magnet and is, at predetermined intervals, you face directly without going through the other member,
motor. In addition to the angle sensor, another angle sensor for detecting the rotation angle of the rotor with respect to the stator is further provided.
The motor according to claim 1. A housing for accommodating the stator and
A cover that seals the space inside the housing with the through hole formed and the shaft penetrated through the through hole.
Further provided with the stator or a lead wire connected to the angle sensor.
The lead wire is routed from the space inside the housing through the inside of the shaft to the outside of the cover.
The motor according to claim 1 or 2. The angle sensor is a magnetic sensor that detects the rotation angle by detecting the angular position of the sensor magnet provided on the rotor.
The motor according to claim 1, 2 or 3. The rotor is arranged so as to surround the outer circumference of the stator and rotates along the outer circumference.
The motor according to any one of claims 1 to 4. An in-wheel motor mounted inside the wheel
With the stator
A rotor that rotates relative to the stator about the rotation axis,
A shaft arranged so as to extend in the axial direction of the rotating shaft,
It is provided with an angle sensor that detects the rotation angle of the rotor with respect to the stator.
The rotor includes a peripheral wall surrounding the outer periphery of the stator and a bottom portion that faces the end of the shaft in the axial direction and has a magnet for a sensor.
The shaft is fixed to the stator and is arranged so as to face the rotor at a predetermined distance in the axial direction.
The angle sensor is arranged at the axial end of the shaft between a portion of the shaft that faces the sensor magnet provided at the bottom of the rotor .
The entire angle sensor entire face of the surface of the sensor magnet and is, at predetermined intervals, you face directly without going through the other member,
In-wheel motor. A wheel device incorporating the motor according to any one of claims 1 to 5 or the in-wheel motor according to claim 6.