JP2000224789A - Rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotating machine capable of moving a frequency band of torque pulsation to high-frequency side and suppressing noise without breaking a rotational balance. SOLUTION: A recessed part 25 is formed at the tee outer-periphery 26 of all tees 23 in the rotor of a rotating machine, and the tee outer-periphery 26 is divided into two section, by which the time of torque pulsation for each tee is two, so that frequency is also doubled. As a result, noise is suppressed, and the recessed part 26 is formed at all the tees 23, thus enabling to prevent a rotational balance from being broken.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine such as a motor or a generator.

[0002]

2. Description of the Related Art A conventional rotary electric machine, for example, taking a wiper motor as an example, generally has a rotor 100 as shown in FIG. Here, the core 110 is formed by laminating a predetermined number of core sheets 120 shown in FIG. 10 as shown in FIG. Then, the shaft 130 press-fitted into the laminated core 110, the commutator 150 fixed to the shaft 130, and the rotor 1
00 is configured.

[0003] A slit opening 145 in the slit 140 of the core 110 is formed in a straight line parallel to the rotation axis direction of the rotor 100. Therefore, when the rotor rotates, the reluctance change due to the slit 140 occurs simultaneously at all positions in the axial direction of the core 110, which causes torque pulsation which causes noise.

Therefore, as a structure for suppressing the generation of torque pulsation, for example, in a power window motor, a plurality of core sheets 220 are laminated as shown in FIGS. In the core 210 completed by sequentially shifting and stacking, both the slit 240 and the slit opening 245 are in a skew state. That is, the shaft 2 pressed into the core 210
30 are formed obliquely to the axial direction.

As a result, when the rotor 200 rotates, the one side 210a in the axial direction of the core 210 moves from the other side 210a.
A reluctance change occurs sequentially up to 10b (reversed by switching the rotation direction). That is, reluctance changes are prevented from occurring at the same time, and the occurrence of torque pulsation is suppressed.

However, by skewing the slit 240 of the core 210 like the rotor 200,
When winding the same number of turns, the winding length becomes longer than when winding the windings around the slits 140 of the core 110 in the rotor 100, and the resistance of the motor increases and the motor characteristics deteriorate.

Further, Japanese Utility Model Laid-Open No. 6-66281 discloses that
A first tooth and a second tooth having two different shapes are provided on the stator (stator) side, and a concave groove is formed at a tip portion of the second tooth on one side.
Thereby, torque pulsation is reduced and noise is suppressed.

[0008] However, the stator (stator) itself is immobile, but it is necessary to consider the rotational balance of the rotor (rotor).

[0009]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a rotating electric machine having a structure capable of moving a frequency band of torque pulsation to a high frequency side and reducing a rotational balance in order to reduce noise. And

[0010]

According to a first aspect of the present invention, there is provided a rotating electric machine comprising: a rotor having a core in which a plurality of teeth are formed radially; and a stator generating a magnetic field. And a concave portion formed at the radial outer periphery of all the teeth and continuously in the axial direction of the core.

According to a second aspect of the present invention, in the rotating electric machine according to the first aspect, a plurality of the concave portions are provided for every tooth.

According to a third aspect of the present invention, in the rotating electric machine according to the first or second aspect, the recess is formed by bending an outer peripheral end of the tooth.

According to the rotating electric machine of the first aspect, usually,
When the rotor of the rotating electric machine rotates, torque pulsation is generated once for each tooth. However, a concave portion formed continuously in the axial direction of the core at the radial outer periphery of all the teeth is formed, thereby reducing the teeth. By dividing the outer periphery in the radial direction into two portions with the concave portion interposed therebetween, the torque pulsation for each tooth becomes twice. As a result, the frequency of the torque pulsation is twice as high as that of one time, and the noise is reduced.

In addition, since all the teeth have the concave portions, a stable rotation can be obtained without a loss of balance during rotation.

According to the rotating electric machine of the present invention, the frequency of the torque pulsation is tripled (at the time of the concave portion 2) and quadrupled (at the time of the concave portion 3; ) To further reduce noise. Of course, concave portions are formed in all the teeth, so that the rotational balance is not lost.

According to the rotating electric machine of the third aspect, since the concave portion is formed by bending the outer peripheral end of the tooth, the concave portion can be formed easily and inexpensively without waste compared with cutting or the like.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment according to the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of a rotating electric machine to which the present invention is applied, and includes conventional rotors 100 (see FIG. 8) and 200 (see FIG. 11).
). FIG. 2 is a plan view of a core in the rotor of FIG. FIG. 3 is an enlarged view of the teeth of a core sheet forming the core of FIG.

The rotor 10 shown in FIG. 1 includes a core 20, a shaft 30, a winding 35, and a commutator 40. Here, the core 20 is formed by laminating a plurality of core sheets (not shown) formed by punching a thin iron plate in the axial direction of the shaft 30. This core sheet is formed by punching in a state where the teeth 23 having the base portion 29 and the outer peripheral end 24 as shown in FIG. That is,
After laminating a plurality of core sheets on which the teeth 23 having the outer peripheral end 24 are formed, fixing the core sheet to the shaft 30, and winding the winding 35 in the slit 22, as shown in FIG. Bent in the direction (toward the center in the radial direction) to form the teeth outer periphery 26.

The punched core sheet has an outer peripheral end 24 formed therein, a notch 27 for facilitating bending, and a concave forming section provided in advance so that a concave 25 is formed when bent. 28 are also formed.

As described above, the core 20 after the lamination of the core sheet, the fixing to the shaft, the winding of the winding, and the bending process is completed. Is formed. Then, the concave portion 25 is formed by bending the outer peripheral end. The recess 25 is formed at the center of the teeth outer periphery 26 in the circumferential direction. Further, the concave portions 25 are formed at the same positions of all the teeth 23, and as a result, the shapes of all the teeth 23 are the same.

The noise when the motor having the rotor 10 with the core 20 mounted thereon is mounted on, for example, an automobile will be described. In general, an automobile body transmits low frequencies well, but high frequencies have large attenuation and a small amount of vibration transmission. Therefore, by shifting the frequency of the torque pulsation generated from the motor to a high frequency range, the transmission of the body and the transmission of noise to the occupant in the vehicle compartment can be reduced. In addition, not only automobiles but also a structure on which a motor is mounted generally exhibits a large attenuation of high-frequency vibration transmission, and thus exhibits the same effect.

The rotor 10 is rotated by energization from an external power supply (not shown), but torque fluctuation occurs in the slit opening 21. Therefore, if there is no concave portion 25, one torque pulsation occurs for each tooth 23. However, both sides are apparently protruded by the recess 25, and the teeth outer periphery 26 is divided into two parts. As a result, two torque pulsations are generated for each tooth 23. Therefore, the frequency of the torque pulsation increases twice.

For example, when a motor mounted on an automobile has a rotation speed of 3000 rpm and 12 teeth (without concave portions), the frequency of torque pulsation is 600 Hz, but the frequency is increased twice to 1200 Hz by the above structure. It is known that transmission of a frequency of 1000 Hz or more is greatly attenuated in an automobile body. At 1200 Hz, vibration transmission is sufficiently attenuated and noise can be reduced. Further, since the concave portions 25 are formed at the same positions of all the teeth 23, the rotational balance is not lost.

Next, a second embodiment according to the present invention will be described with reference to the drawings. FIG. 5 shows a second embodiment of a rotating electric machine to which the present invention is applied, which replaces conventional rotors 100 (see FIG. 8) and 200 (see FIG. 11). FIG. 6 is a plan view of a core in the rotor of FIG. FIG. 7 is an enlarged view of the teeth of the core sheet forming the core of FIG.

The rotor 50 shown in FIG. 5 includes a core 60, a shaft 70, a winding 75, and a commutator 80. Here, the core 60 is formed by laminating a plurality of core sheets (not shown) formed by punching a thin iron plate in the axial direction of the shaft 70. This core sheet is formed by punching with teeth 63 having a base 69 and an outer peripheral end 64 as shown in FIG. That is,
After laminating a plurality of core sheets on which the teeth 63 having the outer peripheral end 64 are formed, fixing the core sheet to the shaft 70, and winding the winding 75 in the slit 62, as shown in FIG. The teeth are bent in the direction (toward the center in the radial direction) to form the teeth outer periphery 66.

The punched core sheet has an outer peripheral end 64 formed therein, a notch 67 for facilitating bending, and a recess forming portion provided in advance so that a recess 65 is formed when bent. 68 are also formed. At this time, in the present embodiment, two concave portion forming portions 68 are also formed so that two concave portions 65 can be formed.

As described above, the core 60 after the lamination of the core sheet, the fixing to the shaft, the winding of the winding, and the bending process is completed. Is formed. Then, the concave portion 65 is formed by bending the outer peripheral end. The recess 65 is formed at a position that divides the teeth outer periphery 26 into three parts. Further, the concave portions 65 are formed at the same positions of all the teeth 63, and as a result, the shapes of all the teeth 63 are the same.

When a motor having the rotor 50 with the core 60 mounted thereon is mounted on an automobile and the rotor 50 is rotated by energization from an external power supply (not shown), both sides thereof are apparently protruded by the concave portion 65, and the outer periphery of the tooth is provided. 66 is divided into three parts. As a result, three torque pulsations are generated for each tooth 63. Therefore, the frequency of the torque pulsation is increased three times.

A motor mounted on an automobile having a rotation speed of 30
When the number of teeth is 00 rpm and the number of teeth (without the concave portion) is 12, the frequency of the torque pulsation increases to 1800 Hz, which is three times that of the case where the concave portion 65 is not provided by the above structure. It is known that transmission of a frequency of 1000 Hz or more is greatly attenuated in an automobile body. At 1800 Hz, vibration transmission is sufficiently attenuated and noise can be reduced. Further, even when the number of the concave portions shown in the first embodiment is one, further attenuation is possible. Moreover, the concave portions 65 are provided at the same positions of all the teeth 63.
Is formed, so that the rotation balance is not lost. Further, by increasing the number of the concave portions 25 and 65, the effect of damping vibration transmission is improved.

In the first and second embodiments, the recesses 25 and 65 are formed by the bending process shown in FIG. 4 so that the recesses 25 and 65 can be formed easily at low cost and the slits 22 of the windings 35 and 75 can be formed easily. , 62 after being wound, the slit opening is largely open at the time of winding (the state shown by the dotted line in FIG. 4), so that the winding operation is easy and leads to an improvement in linear area ratio.

[Brief description of the drawings]

FIG. 1 is a rotor side view showing a first embodiment of a rotating electric machine to which the present invention is applied.

FIG. 2 is a plan view of the core shown in FIG. 1;

FIG. 3 is an enlarged view of teeth before bending processing in a core sheet before lamination for forming the core shown in FIG. 2;

FIG. 4 is an explanatory view of a bending process.

FIG. 5 is a rotor side view showing a second embodiment of the rotating electric machine to which the present invention is applied.

FIG. 6 is a plan view of the core shown in FIG. 5;

FIG. 7 is an enlarged view of teeth before bending processing in a core sheet before lamination for forming the core shown in FIG. 6;

FIG. 8 is a partial sectional view of a wiper motor in a rotating electric machine having a conventional rotor.

FIG. 9 is a view showing a laminated state of the core shown in FIG. 8;

FIG. 10 is a plan view of a core sheet used for the core shown in FIG. 9;

FIG. 11 is a side view of another conventional rotor.

FIG. 12 is a plan view of a core sheet used for the core shown in FIG. 11;

FIG. 13 is a view showing a laminated state of the core shown in FIG. 11;

[Explanation of symbols]

10, 50 ... rotor, 20, 60 ... core, 23, 63 ...
Teeth, 24, 64 ... outer peripheral tip, 25, 65 ... recess,
26, 66 ... teeth outer circumference

Claims (3)

[Claims] 1. A rotating electric machine comprising a rotor having a core in which a plurality of teeth are radially formed, and a stator generating a magnetic field, wherein: A rotating electric machine having a concave portion formed continuously in an axial direction. 2. The rotating electric machine according to claim 1, wherein a plurality of the concave portions are provided for every tooth. 3. The rotating electric machine according to claim 1, wherein the concave portion is formed by bending an outer peripheral end of the tooth.