JPH11122886A - Electric rotating machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve torque characteristic at low rotation and reduce the size and weight of an electric rotating machine by arranging it so that when a rotary shaft, a yoke provided with permanent magnets and coupled with the rotary shaft, and a stator encircling the yoke are provided, making the magnetic characteristics of the yoke variable, depending on the rotation of the rotary shaft, and making the inertial mass of the rotary shaft relatively small. SOLUTION: A centrifugal governor 9 provided with a moving member 16, which moves towards a yoke 8 as the number of rotations of the rotary shaft 6 is increased, is installed on the rotary shaft 6. An auxiliary yoke 21, which reduces the magnetic reluctance of the yoke 8 as the moving member 16 moves towards the yoke 8 and increases the magnetic reluctance of the yoke 8, as the moving member 16 which is moved away from the yoke 8 is coupled with the moving member 16.

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 having a rotating shaft, a yoke having a permanent magnet and coupled to the rotating shaft, and a stator surrounding the yoke. The present invention relates to a rotating electric machine in which the magnetic characteristics of a yoke are changed according to

[0002]

2. Description of the Related Art Conventionally, such a rotating electric machine has been disclosed in Japanese Utility Model Publication No.
Japanese Patent Application Laid-Open No. 0-162977 discloses a fixed yoke which has a permanent magnet and is fixed to a rotating shaft, and a movable yoke which cooperates with the fixed yoke to constitute a yoke rotor. Are arranged so as to sandwich the stator, the centrifugal governor provided on the rotating shaft is connected to the movable yoke, and the operation of the centrifugal governor according to the increase in the rotation speed of the rotating shaft causes the air gap between the stator and the stator to be reduced. The movable yoke is moved in the expanding direction.

[0003]

However, in the above conventional apparatus, it is necessary to move the movable yoke by overcoming the magnetic force of the magnetic circuit formed between the yoke rotor and the stator, so that the operating force of the centrifugal governor is relatively large. Since it is necessary to set the governor weight, the governor weight must be relatively large and heavy, the inertial mass of the rotating shaft increases, and not only the weight and size of the entire rotating electric machine increase, but also the centrifugal governor It is also necessary to secure the strength of the steel.

The present invention has been made in view of the above circumstances, and has been made to make the magnetic characteristics of the yoke variable in accordance with the rotation of the rotating shaft, and to make the inertial mass of the rotating shaft relatively small to reduce the rotational speed. It is an object of the present invention to provide a rotating electric machine that has improved torque characteristics and reduced size and weight.

[0005]

To achieve the above object, a rotating electric machine according to the present invention comprises a rotating shaft, a yoke having a permanent magnet and coupled to the rotating shaft, and a stator surrounding the yoke. And a centrifugal governor provided on the rotating shaft having a moving member that moves closer to the yoke in response to an increase in the number of rotations of the rotating shaft, and a moving member that moves closer to the yoke. And an auxiliary yoke connected to the moving member so as to reduce the magnetic resistance of the yoke and increase the magnetic resistance of the yoke according to the movement of the moving member away from the yoke.

According to such a configuration, the magnetic resistance of the yoke decreases as the number of rotations of the rotating shaft increases, so that the magnetic characteristics of the yoke can be changed according to the rotation of the rotating shaft. In addition, the moving member to which the auxiliary yoke is connected moves closer to the yoke as the rotational speed of the rotating shaft increases, and the suction force from the yoke acts on the auxiliary yoke, which is necessary for the centrifugal governor. And the governor weight can be made relatively small and light, and the inertia mass of the rotating shaft can be reduced to improve the torque characteristics at low rotation. Not only can this be achieved, but also the weight and size of the entire rotating electric machine can be reduced, and the strength required for the centrifugal governor can be relatively small.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

FIGS. 1 to 4 show an embodiment in which the present invention is applied to a motor. FIG. 1 is a longitudinal sectional view of the motor and is a sectional view taken along line 1-1 in FIG. 2 is a sectional view taken along line 2-2 in FIG. 1, FIG. 3 is a sectional view taken along line 3-3 in FIG. 1, and FIG. 4 is a characteristic diagram showing changes in torque and rotation speed accompanying a change in magnetoresistance.

First, in FIG. 1, this motor includes a rotating shaft 6 housed coaxially in a fixed casing 5 and rotatably supported by the casing 5, and a stator 7 fixed to the inner surface of the casing 5. A yoke 8 is fixed to the rotating shaft 5 so as to be surrounded by the stator 7, and a centrifugal governor 9 provided at an end of the rotating shaft 5 so as to face one end surface of the yoke 7 in the axial direction.

Referring also to FIG. 2, the stator 7 has a plurality of, for example, twelve salient poles 10a, 10a,... Stator core 10 and each of the salient poles 10a, 1
0a... Are wound via bobbins 11, respectively.

The yoke 8 is provided with permanent magnets 13, 13,... Extending in a direction parallel to the axis of the rotating shaft 6 at a plurality of places, for example, four places at equal intervals in the circumferential direction of the rotating shaft 6,
The yoke 8 has four receiving holes 14 extending in a direction parallel to the axial direction of the rotating shaft 6 at positions corresponding to each other between the permanent magnets 13 along the circumferential direction of the rotating shaft 6. ,
Each of the receiving holes 14, 14,... Is formed so as to have, for example, a fan-shaped cross-sectional shape.

Referring also to FIG. 3, the centrifugal governor 9 includes:
Weight guide member 1 coaxially fastened to the end of rotating shaft 6
5, a moving member 16 facing the weight member 15,
A plurality of governor weights 17 sandwiched between the weight guide member 15 and the moving member 16;
A spring 18 is provided between the yoke 8 and the moving member 16 by exerting a spring force for urging the 6 toward the weight guide member 15.

The weight guide member 15 is inclined toward the yoke 8 and the stator 7 as the distance from the rotary shaft 6 increases, and is arranged at a plurality of, for example, four, guide plate portions 15a equally spaced in the circumferential direction of the rotary shaft 6. , And the regulating plate portions 15b, 15b, which extend toward the yoke 8 and the stator 7 in a direction orthogonal to the axis of the rotating shaft 6 and are provided on both sides of each of the guide plates 15a, respectively, and the axis of the rotating shaft 6. Are connected to each other in a plane perpendicular to the connecting plates 15b. The connecting plates 15c connect the ends of the restricting plates 15b, 15b,.
And the yoke 8 and the stator 7 of each of the guide plate portions 15a.
And a cylindrical portion 15d which is connected to the connecting plate portions 15c in common with each other, and an end of each of the guide plate portions 15a which is opposite to the yoke 8 and the stator 7 in a plane orthogonal to the axis of the rotating shaft 6. And a support plate portion 15e commonly connected to the portion. A nut 20 is screwed onto a screw shaft 19 provided coaxially at the end of the rotary shaft 6 and penetrating the center of the support plate portion 15e. By being combined, the weight guide member 15 is fixed to the end of the rotating shaft 6.

The moving member 16 is made of a magnetic metal, and has a cylindrical moving tube portion 16a for fitting the rotary shaft 6 so as to be relatively slidable, and a radially outward portion from an intermediate portion of the moving tube portion 16a. A flange 16b extending over the flange 16;
is inserted into the cylindrical portion 15d of the weight guide member 15 so as to face the guide plate portions 15a of the weight guide member 15.

Each of the governor weights 17 is formed in the shape of a roller, and the movement of the rotary shaft 6 along the circumferential direction is regulated by the regulating plate portions 15b.
.. And the flange 16b. Also spring 18
Is a coil spring that surrounds the rotating shaft 6, is provided between the yoke 8 and the flange 16b of the moving member 16, and connects the governor weights 17 to the guide plate 15a and the flange 16b.
It exerts a spring force for urging the moving member 16 so as to be sandwiched therebetween.

According to such a centrifugal governor 9, each governor weight 17 is moved radially outward of the rotary shaft 6 between the guide plate portion 15a and the flange portion 16b by the centrifugal force acting according to the rotation of the rotary shaft 6. , And the guide plate portions 15a inclined toward the stator 7 and the yoke 8 toward the radially outward side of the rotating shaft 6 are fixed to the rotating shaft 6, so that the governor weights 17 ... The flange 16b, that is, the moving member 16 is moved toward the stator 7 and the yoke 8 against the spring force of the spring 18.

The flange 16b of the moving member 16 has a rotating shaft 6
One end of each of four auxiliary yokes 21 extending in a direction parallel to the axis of the auxiliary yoke 21 is integrally connected. The other end of each of the auxiliary yokes 21 is connected to each of the receiving holes 14 provided in the yoke 8. It is slidably fitted. Therefore, the relative angular displacement of the moving member 16 with the yoke 8 is prevented, and the moving member 16 rotates together with the rotating shaft 6 and the yoke 8.

Further, at the position where the moving member 16 is separated from the yoke 8 (the position shown in FIG. 1), the auxiliary yokes 21 are fitted in only a part of the accommodation holes 14 of the yoke 8, and 8, a relatively large gap is formed between the permanent magnets 13.
When the moving member 16 moves close to the yoke 8, the auxiliary yokes 21 are fitted into most of the receiving holes 14 of the yoke 8. Air gaps hardly occur between the permanent magnets 13..., And the magnetic resistance of the yoke 8 decreases.

Next, the operation of this embodiment will be described. The function of the centrifugal governor 9 in response to the increase in the number of rotations of the rotating shaft 6 allows the auxiliary yokes 21. Since the yoke 8 moves in the increasing direction, the magnetic resistance of the yoke 8 decreases, and the magnetic characteristics of the yoke 8 can be changed according to the rotation of the rotating shaft 6.

The rotational speed and torque when the magnetic resistance of the yoke 8 is increased by using a part of the receiving holes 14 as voids in accordance with the exciting current to each coil 12 of the stator 7 are shown by solid lines in FIG. It changes as shown,
The rotation speed and torque when the magnetic resistance of the yoke 8 is reduced by filling most of the receiving holes 14 with the auxiliary yokes 21... In accordance with the exciting current to each coil 12.
The output characteristics of the motor can be changed in accordance with the change in the magnetic resistance of the yoke 8.

Further, the moving member 16 to which the auxiliary yokes 21...
Since the suction force from the yoke 8 acts on the auxiliary yokes 21..., The operating force required by the centrifugal governor 9 is relatively small. Therefore, the governor weights 17 can be made relatively small and lightweight, and the inertia mass of the rotating shaft 6 can be reduced, so that not only the torque characteristics at low rotation can be improved, but also the motor speed can be improved. The overall weight and size can be reduced, and the strength required for the centrifugal governor 9 can be relatively small.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

For example, the present invention is applicable not only to motors but also to generators. In the above embodiment, a part of the auxiliary yokes 21 is fitted in the receiving holes 14 even when the rotation speed of the rotary shaft 6 is low, but the moving member 16 is mounted on the rotary shaft 6 so as to be relatively non-rotatable. With such a configuration, the rotating shaft 6
When the rotation speed of the auxiliary yoke 21 is low, the whole
4..., And the receiving hole 14 may be a bottomed one having the opposite side to the centrifugal governor 9 closed.
Further, the cross-sectional shape of the housing hole 14 is not limited to a sector shape.

[0024]

As described above, according to the present invention, the magnetic characteristics of the yoke are made variable according to the rotation of the rotating shaft, and the operating force required by the centrifugal governor is made relatively small. Not only improves the torque characteristics at low speeds, but also reduces the weight and size of the rotating electrical machine, and also compares the strength required for centrifugal governors. Can be very small.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a motor taken along line 1-1 of FIG. 2;

FIG. 2 is a sectional view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 1;

FIG. 4 is a characteristic diagram showing a change in torque and rotation speed accompanying a change in magnetoresistance.

[Explanation of symbols]

 Reference Signs List 6 rotating shaft 7 stator 8 yoke 9 centrifugal governor 13 permanent magnet 16 moving member 21 auxiliary yoke

Claims (1)

[Claims] 1. A rotating shaft (6), a yoke (8) having a permanent magnet (13) and coupled to the rotating shaft (6), and a stator (7) surrounding the yoke (8). And a centrifugal governor (9) provided on the rotating shaft (6) and having a moving member (16) that moves closer to the yoke (8) in accordance with an increase in the rotation speed of the rotating shaft (6). )When,
The magnetic resistance of the yoke (8) is reduced according to the movement of the moving member (16) toward the yoke (8), and the yoke (8) is controlled according to the movement of the moving member (16) away from the yoke (8). ) To increase the magnetic resistance of the auxiliary yoke (2) connected to the moving member (16).
1) A rotating electric machine comprising: