JP3709726B2 - motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
This invention relates to motors, in particular, to a variable reactance (VR) type stepping motor for generating a relatively high output.
[0002]
[Prior art]
At present, there are an inner rotor type and an outer rotor type as stepping motors, and the inner rotor type is generally used. In the interrotor type, a coil is disposed on the outer periphery (stator) side, and a rotor is disposed on the inner side.
[0003]
[Problems to be solved by the invention]
However, in the inner rotor type, since the rotor is arranged inside the coil as described above, in order to increase the torque of the motor, it is necessary to increase the rotor diameter, and the motor is enlarged. That is, since the torque is proportional to the diameter of the rotor, it is inevitable to increase the diameter of the motor in order to increase the torque.
[0004]
The present invention has been made to solve the above problems, and an object is to provide a Motor capable of generating high torque small diameter.
[0005]
[Means for Solving the Problems]
Motor according to claim 1, in order to achieve the above object, a rotor body formed of the teeth on the outer circumference,
A stator body disposed outside the rotor body and having teeth formed on the inner periphery;
An annular groove formed in the rotor body along the rotation direction;
Is fixed to the stator body, and a coil positioned within the annular groove, Ri Tona,
The teeth formed on the inner periphery of the stator body are divided into two with respect to the axial direction of rotation of the rotor body, and a part of the coil is fixed between the two divided teeth. Characteristic.
[0007]
According to a second aspect of the present invention, the motor according to the first aspect is characterized in that a permanent magnet is disposed between the teeth of the stator divided in two.
[0008]
According to a third aspect of the present invention, there is provided a motor according to the first or second aspect , wherein the rotor body and the stator body are arranged in a plurality along the rotation axis of the rotor, and the rotor body and the stator body are not arranged. A technical feature is that a magnetic material is disposed.
[0009]
According to a fourth aspect of the present invention, there is provided the motor according to the first to third aspects, wherein the annular groove formed in the rotor body is configured to have a narrow opening and a wide internal width.
A technical feature is that the coil has a narrow portion corresponding to the opening of the annular groove and a wide portion corresponding to the inside.
[0010]
According to a fifth aspect of the present invention, the motor according to the fourth aspect is characterized in that the rotor body includes an open portion for opening a side portion of the annular groove.
[0011]
In the first aspect of the present invention, since the coil is housed in the annular groove formed in the rotor body and is not disposed outside the rotor, the diameter of the rotor is increased. Therefore, it is possible to generate a high torque at a small diameter motors.
[0012]
In the invention of claim 2, since is arranged a permanent magnet between the stator teeth, strengthened magnetic force generated in the stator, it may increase the torque generated by the motors.
[0013]
In the invention of claim 3 , since two or more rotor bodies are provided, the self-start can be performed by shifting the tooth positions of the rotor bodies. On the other hand, by providing three or more rotor bodies, the gogging torque can be weakened and the rotor can rotate smoothly.
[0014]
In the invention of claim 4 , since the annular groove has a narrow opening, the width of the teeth on the outer periphery of the rotor can be increased, and the coil has a width corresponding to the inside of the annular groove. Since it is configured widely, the number of turns can be increased. Therefore, it is possible to increase the torque of the motors.
[0015]
In the fifth aspect of the invention, since the rotor body has an open portion for opening the side portion of the annular groove, the coil can be easily disposed in the annular groove having a narrow opening.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a stepping motor according to an embodiment of the present invention will be described with reference to the drawings.
1A shows a longitudinal section of the stepping motor 10 according to the first embodiment, and FIG. 1B shows a section BB of the stepping motor 10 in FIG. 1A. This stepping motor is configured as an inner rotor type in which a rotor 30 fixed to a shaft 12 is disposed inside a stator 20. In the stepping motor 10 according to the first embodiment, the rotor 30 includes three sets of cylindrical rotor bodies 32U, 32V, and 32W, and an annular groove 40 is formed at the center of each rotor body. In the annular groove 40, coils 50U, 50V, 50W having one end fixed on the stator 20 side are accommodated.
[0017]
The rotor body 32U is provided with teeth 34 having a salient pole structure on the outer periphery in the radial direction. FIG. 2A shows the rotor body 32U and the state before the assembly of the rotor body 32U. The rotor body 32U is composed of a pair of magnetic bodies of a main body portion 32A and an open portion 32B. Here, the annular groove 40 formed in the rotor 30 is configured such that the width of the opening 40a is narrow and the width of the inside 40b is wide. As shown in FIG. 1A, a non-magnetic aluminum spacer 42 is interposed between the rotor body 32U and the rotor body 32V and between the rotor body 32V and the rotor body 32W. It is fixed.
[0018]
The configuration of the coil 50U disposed in the annular groove 40 via a certain air gap is shown in FIGS. 2 (B) and 2 (C). Here, FIG. 2 (B) is a plan view of the coil 50U, and FIG. 2 (C) is a CC cross-sectional view of the coil 50U in FIG. 2 (B). In the center of the coil 50U, a through hole 50c for accommodating in the fitting groove 40 is formed. And the neck part 50a corresponding to the opening part 40a (refer FIG. 2 (A)) of the annular groove 40 mentioned above is formed thin, On the other hand, the site | part 50b corresponding to the inside 40b of the said annular groove 40 is the It is formed thick. On the outer peripheral side of the thin neck portion 50a, as shown in FIG. 1 (A), a ring portion 50d for accommodating in a recess 26 formed between the teeth 24 on the stator 20 side is formed. And the convex part 50e is formed in the outer periphery of this ring part 50d. The convex portion 50e is formed for positioning when the coil 50U is assembled and for preventing the coil 50 from rotating. The coil 50 </ b> U is formed in the above shape by hardening the wiring with resin, and a U-phase sine wave alternating current is applied via the lead wire 52.
[0019]
On the other hand, as the stator 20, as shown in FIG. 1A, three sets of stator bodies 20U, 20V, and 20W are arranged so as to correspond to the rotor bodies 32U, 32V, and 32W described above. The stator bodies 20U, 20V, 20W are made of an annular magnetic body, and teeth 24 having a salient pole structure are formed on the inner periphery in the radial direction. The teeth 24 are divided into two with respect to the axial direction of rotation of the rotor bodies 32U, 32V, 32W, and the coils 50U, 50V, 50W ring portions 50e are respectively fitted and fixed. Between the stator body 20U and the stator body 20V, and between the stator bodies 20V and 20W, an aluminum spacer 44 which is a non-magnetic material is interposed and fixed to the housing 14. On the other hand, the shaft 12 on the rotor 30 side is rotatably fixed to the housing 14 via a bearing 48.
[0020]
The stepping motor 10 applies a sinusoidal alternating current having a phase difference of 120 degrees to the coils 50U, 50V, and 50W, so that the magnetic flux passing through the stator body 20U and the rotor body 32U, and the stator body 20V and the rotor body 32V Further, a magnetic flux passing through the stator body 20W and the rotor body 32W is formed, and an attractive / repulsive force is generated between the stator side teeth 24 and the rotor side teeth 34, and the rotor 30 side Generate torque.
[0021]
In the stepping motor 10 of this embodiment, the coils 50U, 50V, and 50W are accommodated in the annular grooves 40 formed in the rotor bodies 32U, 32V, and 32W, respectively. That is, since the coils 50U, 50V, and 50W are not arranged outside the rotor 30, the diameter of the rotor 30 is increased in the stepping motor having the same diameter. Here, the torque generated by the stepping motor 10 is proportional to the diameter T of the rotor 30 (see FIG. 1A) and is proportional to the number of teeth disposed on the surface of the rotor 30. In this embodiment, the torque of the rotor 30 is increased by increasing the diameter of the rotor 30, and the torque is increased by increasing the number of teeth disposed on the surface by increasing the diameter of the rotor 30. Torque can be generated.
[0022]
Since the stepping motor of the first embodiment includes the three rotor bodies 32U, 32V, and 32W, the gogging torque can be weakened and the motor can rotate smoothly. For this reason, it can be suitably used for an electric power steering of an automobile in which steering feeling is important.
[0023]
Further, in the stepping motor, as shown in FIG. 2A, the annular groove 40 is formed so that the width of the opening 40a is narrow, so that the width W of the teeth 34 on the outer periphery in the radial direction of the rotor 30 can be increased. In addition, since the coils 50U, 50V, and 50W are configured so that the width of the portion 50b corresponding to the inside 40b of the annular groove is wide, the number of turns can be increased. For this reason, the torque in the stepping motor can be increased.
[0024]
Further, as described above with reference to FIG. 2A, the rotor body 32U is composed of a pair of magnetic bodies of the main body portion 32A and the opening portion 32B for opening the side portion of the annular groove 40. Therefore, after accommodating the coil 50U with the opening 32B removed, the coil 50U can be easily placed in the narrow annular groove 40 of the opening 40a by assembling the opening 32B. Can do.
[0025]
Further, in this embodiment, the rotor bodies 32U, 32V, 32W and the stator bodies 20U, 20V, 20W are separated by the spacers made of aluminum having substantially the same magnetic permeability as the air, so that the rotor bodies 32U, 32V are separated. , 32W and between the stator bodies 20U, 20V, 20W, the leakage of the magnetic flux between the phases is reduced, and it can be driven with high efficiency.
[0026]
Furthermore, in this embodiment, since the rotor 30 is provided with the annular groove 40 while achieving a relatively large rotor 30 diameter, the rotor 30 can be configured to be lightweight (low inertia weight). For this reason, the power consumption when switching the rotation direction is small, and it can be suitably used for an electric power steering or the like that repeats forward and reverse rotation.
[0027]
Subsequently, a modified example of the first embodiment will be described. FIG. 3 shows a stepping motor 10 ′ according to a modification of the first embodiment. In the configuration described above with reference to FIG. 1, three sets of rotor bodies 32U, 32V, and 32W are used as the rotor. On the other hand, in the modified example of FIG. 3, two sets of rotor bodies 32U and 32V are used. In this modified example, since the tooth positions 34 and 34 of the rotor bodies 32U and 32V are shifted from each other, the coils 50U and 50V can be self-started by applying a sinusoidal alternating current having a phase difference of 90 degrees.
[0028]
A stepping motor 110 according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 4A is a longitudinal sectional view of the stepping motor 110 according to the second embodiment, and FIG. 4B is a DD cross-sectional view of the stepping motor 110 in FIG. 4A. The stepping motor 110 of the second embodiment has the same configuration as that of the stepping motor 10 of the first embodiment, except that the permanent magnets 60 are disposed on the stator bodies 20U, 20V, and 20W of the stator 20. ing.
[0029]
That is, in the stepping motor 110 of the second embodiment, as shown in FIG. 4A, the stators 20U, 20V, and 20W are divided into two parts so as to sandwich the permanent magnets 60 in order to dispose the permanent magnets 60. Is formed. As shown in FIG. 4B, the permanent magnet 60 is divided into six pieces, and as shown in FIG. 4A, the permanent magnet 60 arranged in the stator body 20U is In the figure, the outside is the S pole and the inside is the N pole. The permanent magnet 60 of the stator body 20V has an N pole on the stator 20U side, and the stator body 20W has an S pole. The permanent magnet 60 of the stator body 20W has an S pole on the stator body 20V side and an N pole on the outside. Are arranged as follows.
[0030]
The operation of the stepping motor 110 according to the second embodiment will be described with reference to FIG.
FIG. 5 shows the left side (outside) teeth 34 of the rotor body 32U in FIG. 4A and the teeth 24 of the rotor body 32U facing the teeth 34 in a planar shape. FIG. 5A shows that the rotor-side teeth 34 are magnetized to the S pole side by the coil 50U to which a sine wave alternating current is applied, and the rotor-side teeth 24 are magnetized to the N pole. 30 shows a state in which the torque indicated by the arrow is generated. Here, the stator side teeth 34 are magnetized by the permanent magnet 60 and generate a torque higher than the torque generated by the magnetic force of only the coil 50U. Here, the magnetic flux between the teeth 24 and 34 is indicated by a chain line arrow in the figure. During this adsorption, no leakage magnetic flux is generated between both teeth.
[0031]
In the embodiment described above, an example in which the configuration of the present invention is applied to a stepping motor has been described. However, this configuration can also be applied to a stator, a hybrid motor using a magnet for a housing, or a motor using an adsorption reaction force.
[0032]
【The invention's effect】
As described above, in the stepping motor of the present invention, since the coils are accommodated in the annular grooves formed in the rotor body, the diameter of the rotor is increased in the stepping motor having the same diameter. For this reason, high torque can be generated by a small-diameter stepping motor.
[Brief description of the drawings]
FIG. 1A is a longitudinal sectional view of a stepping motor according to a first embodiment, and FIG. 1B is a cross-sectional view taken along the line BB of the stepping motor in FIG. 1A.
FIG. 2A is a cross-sectional view showing the rotor body of the first embodiment and a state before assembly of the rotor body, and FIG. 2B is a plan view of the coil of the stepping motor of the first embodiment. FIG. 2C is a CC cross-sectional view of the coil in FIG.
FIG. 3A is a longitudinal sectional view of a stepping motor according to a modification of the first embodiment, and FIG. 3B is a cross-sectional view of the stepping motor taken along the line BB in FIG. 3A. It is.
4A is a longitudinal sectional view of the stepping motor according to the second embodiment, and FIG. 4B is a cross-sectional view taken along the line DD of the stepping motor in FIG. 4A.
FIG. 5 is an explanatory diagram illustrating the principle of torque generation in the stepping motor according to the second embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Stepping motor 12 Axis 20 Stator 20U, 20V, 20W Stator body 24 Teeth 30 Rotor 32U, 32V, 32W Rotor body 32A Main body part 32B Open body 34 Teeth 40 Annular groove 40a Opening part 40b Inner 42 Spacer (non-magnetic body)
50 coils 60 permanent magnets

Claims (5)

A rotor body with teeth formed on the outer periphery;
A stator body disposed outside the rotor body and having teeth formed on the inner periphery;
An annular groove formed in the rotor body along the rotation direction;
Is fixed to the stator body, and a coil positioned within the annular groove, Ri Tona,
The teeth formed on the inner periphery of the stator body are divided into two with respect to the axial direction of rotation of the rotor body, and a part of the coil is fixed between the two divided teeth. motor to be. The motor according to claim 1, wherein a permanent magnet is disposed between the teeth of the two divided stators. While arranging a plurality of the rotor body and stator body along the rotation axis of the rotor, to claim 1 or claim 2, characterized in that a non-magnetic material between the plurality of rotor body and stator body The motor described . The annular groove formed in the rotor body is configured to narrow the width of the opening and widen the internal width,
4. The motor according to claim 1, wherein the coil has a narrow width corresponding to the opening of the annular groove and a wide width corresponding to the inside. 5. The motor according to claim 4, wherein the rotor body includes an opening portion for opening a side portion of the annular groove.

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