JPH10322946A - Electrical rotating machine and its rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily rotate a motor or the like at a start and rotate it stably during rotation. SOLUTION: In a rotor core 11a, a plurality of spaces 19, 19,... are made. Permanent magnets 35, 35,... are fixed to the rotary shaft side of each space 19, 19,..., and a iron powder 30 is put in each space 19. When a motor is stationary, the iron powder 30 sticks to the permanent magnet 35, so that the inertial moment of the rotor 10a becomes small, and during the rotation of the motor, the centrifugal force applied to the iron powder 30 surpasses the magnetic force of the permanent magnet 35, and the iron powder 30 is positioned on the outer periphery side of the space 19, so that the inertial moment of the rotor 10a becomes large.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a rotor of an induction motor (induction motor), for example, as shown in FIG. 14, there is a cage-shaped rotor 10. This cage type rotor 1
Reference numeral 0 denotes a rotating shaft, as shown in FIG. 15, a rotor core 11 in which a large number of disk-shaped steel sheets having good magnetic properties such as silicon steel sheets are laminated, and one of the rotor cores 11 as shown in FIG. The plurality of bars 24, 24, 24, 24,
, And a pair of end rings 23 connected to both ends of each bar 24, 24,. Each of the bar 24 and the end ring 23 is formed of a conductive material such as aluminum or copper, and these are integrated to form the conductor cage 21. End ring 23
Are mounted with cooling fins 27 and balance pins 26 for maintaining the dynamic balance of the rotor 10 during rotation. In order to achieve dynamic balance, balance pin 2
There is also a case where a part of the end ring 23 is cut without providing 6.

[0003]

The present invention is not limited to the induction motor described above, but any rotary motor, or even a rotary generator, is designed to start rotating easily at startup.
It is preferable that the moment of inertia of the rotor is small, and it is preferable that the moment of inertia of the rotor be large so that once it starts rotating, it stably rotates.

[0004] In other words, the contradictory properties of the rotor, which have a small moment of inertia during startup and a large moment of inertia during rotation, have conventionally been required. For this reason, in the related art, it is extremely difficult to determine the weight of the rotor.

According to the present invention, in response to the above contradictory demands, it can be easily rotated at the time of starting,
It is an object of the present invention to provide a rotor capable of performing stable rotation during rotation, and an electric rotating machine including the rotor.

[0006]

According to a first aspect of the present invention, there is provided a rotor for an electric rotating machine, wherein a space is formed in a rotor core so as to extend from a rotating shaft side close to a rotating shaft to an outer peripheral side far from the rotating shaft. Within, the mass member movable between the rotation axis side and the outer peripheral side of the space, and the mass member with a force weaker than the centrifugal force applied to the mass member at the time of rotation at a specific rotation speed or more. And a biasing means for biasing from the outer peripheral side to the rotating shaft side.

Here, in the rotor of the electric rotating machine described above, a plurality of the spaces are formed radially around the rotation axis in the core, and the mass members are respectively formed in the plurality of the spaces. Preferably, they are arranged. In this case, it is preferable that the masses of the mass members respectively arranged in the plurality of spaces are adjusted so as to obtain a dynamic balance when the rotation shaft and the core are rotated around the rotation shaft. .

In the rotor of each of the electric rotating machines described above, the mass member is a magnetic material, and the urging means is
It may be a permanent magnet or an electromagnet.

[0009] The biasing means may be a spring for biasing the mass member from the outer peripheral side to the rotating shaft side. In this case, the mass member and the spring may be integral and constitute a part of the core.

[0010] Further, an electric rotating machine for achieving the above object has any one of the above rotors, a stator disposed around the core of the rotor, and the rotor having the rotating shaft. A casing that covers the core and the stator of the rotor so as to be rotatable about a center.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments according to the present invention will be described below with reference to the drawings.

First, an electric motor (motor) according to a first embodiment of the present invention will be described. As shown in FIG. 13, the electric motor in this embodiment is a three-phase induction motor, and includes a rotor (rotor) 10a, a stator (stator) 40 arranged around the rotor 10a, and a rotor 1
Bearings 44, 44 for rotatably supporting the rotating shaft of Oa;
And a casing 45 for covering them. Stator 4
0 has a stator core 41 and a stator coil 42 provided around the stator core 41. The stator core 41 is fixed to an inner wall surface of the casing 45. The rotor 10a includes a rotor shaft 11a, a rotor core 11a (shown in FIG. 5) in which disk-shaped core pieces made of a material having good magnetic properties such as a silicon steel plate are laminated, and a rotor core 11a.
And a conductor basket type 21 (shown in FIG. 16) to be incorporated in the device.

The conductor cage 21 of the rotor 10a is shown in FIG.
As described in the related art using a plurality of bars 24, one end face of the rotor core 11a penetrates the other end face.
, And a pair of end rings 23 connected to both ends of each bar 24, 24,. The bar 24 and the end ring 23 are formed of a conductive material such as copper or aluminum.

The core pieces 12, which form the rotor core 11a,
As shown in FIG. 5, the end core pieces 12 forming both ends of the rotor core 11a and the rotor core 11a
And an intermediate part core piece 16 forming an intermediate part of the above. As shown in FIG. 4, the disk-shaped end core piece 12 has a rotation shaft insertion hole 15 through which a rotation shaft 25 passes, and has bars 24, 24,. Are formed through which a plurality of slots 14 pass. As shown in FIG. 3, the disk-shaped intermediate core piece 16 has a rotary shaft insertion hole 15 and a plurality of slots 14, 14,. Four fan-shaped openings 17, 17,... Are formed. Four openings 1
Are formed between the rotation shaft insertion hole 15 and the slot 14 and at positions where the angles of the adjacent openings 17 around the rotation shaft insertion hole 15 are the same. I have. As shown in FIG. 5, a number of intermediate core pieces 16, 16,... Are stacked so that the position of the rotary shaft insertion hole 15, the position of the corresponding slot 14, and the position of the corresponding opening 17 coincide with each other. You. The two end core pieces 12, 12
Are attached to both end surfaces of a cylindrical body formed by laminating a large number of intermediate core pieces 16, 16,.... At this time, the position of the rotation shaft insertion hole 15 of the intermediate core piece 16 and the position of the rotation shaft insertion hole 15 of the end core piece 12 match, and the position of the slot 14 of the intermediate core piece 16 matches the position of the end core piece. The positions of the twelve slots 14 match. As described above, the rotor core 11a formed by laminating the core pieces 12 and 16 has four edges surrounded by the edges of the openings 17 of the many intermediate core pieces 16 and the end core pieces 12. Spaces 19, 19,... Are formed.

The four spaces 19, 1 of the rotor core 11a
As shown in FIG. 1, iron powder 30 is put in each of 9, 9,..., And a permanent magnet 35 is fixed to the rotating shaft side. The magnetic force of the permanent magnet 35 will be described later. The process of arranging the iron powder 30 and the permanent magnets 35 in the space 19 is performed after a large number of intermediate core pieces 16, 16,... Are laminated and before the end core pieces 12 are attached. .

After the completion of the rotor core 11a, the conductor cage 21 is formed and attached to the rotor core 11a. In forming the conductive cage 21, a die casting method is employed. In this die-casting method, a mold in which the rotor 10a fits is used, the completed rotor core 11a is set in the mold, and then the molten metal for forming the conductor cage 21 is injected into the mold, and the conductor is injected. The bar 24 and the end ring 23 of the cage 21 are integrally formed. In this process, the cooling fins may be formed integrally with the end ring 23. Also,
In the formation of the conductor cage 21, in addition to the above-described die casting method, the bar 24 and the end ring 23 of the conductor cage 21 are separately prepared, and the slots 14, 14,. After inserting the bars 24, 24,... Into the end rings 2 at both ends of the bars 24, 24,.
There is also a method of welding 3,23.

Next, the operation of the above motor will be described. As described in "Problems to be Solved by the Invention", the rotor 10a of the electric motor has a small moment of inertia at startup and a large moment of inertia at rotation.
Conflicting properties are required.

The moment of inertia J in question is, as shown in FIG. 2, a cylinder having a length L, an outer diameter D, an inner diameter d, and a density ρ, the center axis of which is the rotation axis. In this case, the value is represented by the following equation. J = πρL (D ² −d ² ) / 32 Considering this equation, the moment of inertia J decreases when the outer diameter is small, and increases when the outer diameter is large. In other words, the rotation of the mass object It can be seen that it becomes smaller when the radius is small, and becomes larger when the radius of gyration of the mass is large.

Therefore, in this embodiment, during the transition from the start to the rotation, the iron powder 30 in the rotor core 11a is removed.
Is moved, that is, the radius of gyration of the mass is changed, thereby changing the moment of inertia of the rotor 10a, thereby realizing the contradictory properties described above.

That is, at the time of start-up, as shown in FIG. 1A, in the space 19 of the rotor core 11a, the iron powder 30 is attached to the permanent magnet 35 on the rotating shaft side, and the radius of rotation of the iron powder 30 is reduced. By reducing the rotation speed, the moment of inertia of the rotor 10a is reduced, and when the rotation speed reaches or reaches the rated rotation speed, as shown in FIG. 1B, the centrifugal force applied to the iron powder 30 is reduced by the magnetic force (biasing force) of the magnet. In addition, the centrifugal force causes the iron powder 30 to adhere to the outer peripheral edge in the space 19 of the rotor core 11a to increase the radius of rotation of the iron powder 30 so that the rotor 1
The moment of inertia of 0a is increased.

As a result, at the time of startup, since the moment of inertia of the rotor 10a is small, the rotor 10a starts rotating with a small current, and once the rotor 10a rotates, the moment of inertia of the rotor 10a decreases. Since it becomes larger, the rotor 10a rotates stably. In addition, since the inertia moment of the rotor 10a is reduced not only at the time of starting but also at the time of stopping, the stopping torque for stopping the rotor 10a can be reduced.

By the way, when the rotor 10a has a specific rotation speed or more, it is important to determine how much magnetic force is used for the iron powder 30 to adhere to the outer peripheral edge in the space 19 of the rotor core 11a. become. Thus, for example, the angular velocity ω of the rotor 10a at the time of the minimum rotation of the motor and the rotation axis 2
5 to the outer peripheral edge in the space 19, that is, the iron powder 30
Is obtained from the radius of rotation r when the outer surface of the motor 19 is attached to the outer peripheral edge in the space 19, and the centrifugal force F (= mrω ² m: mass of the iron powder 30) applied to the iron powder 30 at the time of the minimum rotation of the motor is obtained. A magnet that emits a magnetic force slightly weaker than F is used.

This embodiment also has the effect that dynamic balance can be relatively easily achieved. In the prior art, when the dynamic balance is obtained, the dynamic balance is measured after the rotor 10 is manufactured, and a part of the end ring 23 is cut off or the balance pin 26 is attached to the end ring 23 based on the measurement result. Or weld it. On the other hand, in this embodiment, after manufacturing the rotor 10a and measuring the dynamic balance of the rotor 10a, the amount of the iron powder 30 put in the four spaces 19 is adjusted based on the result. Thus, a dynamic balance can be obtained. Therefore, it is not necessary to set the rotor 10a on the grinding device and delicately control the grinding amount or the like in order to grind the end ring 23.

By the way, in order to achieve the dynamic balance by the above-described method, it is necessary to put the iron powder 30 into the rotor core after manufacturing the rotor in place of the above-described manufacturing procedure. . For this reason, in the manufacturing process of the rotor, the rotor core is formed only by the intermediate core piece 16 described above with reference to FIGS. 3 and 5, and the rotor core is formed into a cage by die casting or the like. Form the conductor. Then, in a state in which both ends of the space 19 in the axial direction are open, the dynamic balance of the rotor is measured by rotating the rotor or the like, and based on the measurement result, each space 19 of the rotor core is measured. After an appropriate amount of iron powder 30 is added, the open portion of the space 19 is closed.

Actually, when the amount of the iron powder 30 in each space 19 is adjusted to achieve a dynamic balance, at least four spaces 19 are required as in the above embodiment. For example, as shown in FIG. 6, six or more spaces 19b, 1
9b,... For example, in the rotor core 11b (second embodiment) shown in FIG.
When there are relatively many cavities around 4b, four spaces cannot cope, but in this way, six spaces 19b, 19b,
If ... there is, fewer put the iron powder 30 in the space 19b ₁ bar 24a near the space 19b ₂ bars 24b near by putting larger amount iron powder 30 may take the dynamic balance.

Next, an electric motor according to a third embodiment of the present invention will be described with reference to FIG. In this embodiment, an electromagnet is used instead of the permanent magnet 35 as the urging means of the iron powder 30 in the first embodiment. That is, in this embodiment, although a space is formed in the rotor core 11c, no permanent magnet is provided therein, and instead, a space is formed at the end of the rotating shaft 25 formed of a magnetic material. , A coil 35c for magnetizing the rotating shaft 25 is wound. A power supply circuit 37 having a power supply 38 and a variable resistor 39 is connected to the coil 35c via a slip ring 36.

Therefore, by operating the variable resistor 39 to change the magnetic force generated by the coil 35c,
It is possible to change the number of rotations at which the shaft moves from the rotation shaft side to the outer circumference side, in other words, it is possible to obtain an optimum moment of inertia according to the number of rotations. As described above, in the present embodiment in which the electromagnet is used instead of the permanent magnet, an optimal moment of inertia corresponding to the rotation speed can be easily obtained. When the present invention is applied to an electric motor, the characteristics and efficiency of the electric motor can be further improved.

Next, an electric motor according to a fourth embodiment of the present invention will be described with reference to FIG. This embodiment uses an iron ball 30d instead of the iron powder 30 in the above embodiment.

In the rotor core 11a, a plurality of spaces 19d, 19d,
... are formed. Each space 19d, 19d, ...
One iron ball 30d is inserted. The space 19d has the same width as the diameter of the iron ball 30d and extends in the radial direction of the rotor core 11d. That is, the space 19d is the iron ball 30d
Can move only in the radial direction, and cannot move in the circumferential direction. The magnet 35 d is embedded between the rotating shaft 25 side edge of each space 19 and the rotating shaft 25.

At the time of startup, the iron ball 30d is placed in the space 19
It is located on the rotating shaft side in d. The rotor starts to rotate,
When the rotation speed exceeds a certain value, the centrifugal force applied to the iron ball 30d exceeds the magnetic force of the magnet holding the iron ball 30d, and the iron ball 30d is located on the outer peripheral side in the space 19d.

Therefore, even in the configuration as in this embodiment,
Basically, the same effect as in the first embodiment can be obtained. In this embodiment, the iron ball 30d is placed in the space 19
Although the permanent magnet 35d is used as the urging means for urging the rotating shaft side in d, an electromagnet may be used instead, similarly to the third embodiment. When the dynamic balance is to be obtained, for example, a method in which the iron ball 30d is not inserted into one or two of the spaces 19d, 19d,. Alternatively, this may be put in any of the spaces 19d according to the measurement result of the dynamic balance.

Next, an electric motor according to a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the iron powder 3 as a mass member in the first embodiment is used.
0, and an iron ball 30d is used as a mass member in place of the magnet 30 as the urging means, and a spring 35 is used as the urging means.
e, 35f. The springs 35e and 35f as the urging means may be a coil spring 35e or a plate spring 35f. In this embodiment,
The leaf spring 35f is formed by a part of the rotor core 11e. In this case, at the stage of forming the core piece of the rotor core 11d, the opening (the space 19) is left except for the portion that becomes the leaf spring 35f.
The core piece is punched out to form a leaf spring 35f together with the opening so as to form a portion that becomes d.

Next, an electric motor according to a sixth embodiment of the present invention will be described with reference to FIG. In this embodiment, a mass portion 30g as a mass member and a plate spring portion 35g as an urging means are formed by a part of the rotor core 11g. That is, in this embodiment, as in the fifth embodiment, at the stage of forming the core piece of the rotor core 11g, the opening (the part that becomes the space 19g) except for the part that becomes the mass part 30g and the leaf spring part 35g. The core piece is punched out to form the mass part 30g and the leaf spring part 35g together with the opening so that the shape (1) is formed.

As described above, in this embodiment, at the same time when the opening is formed in the core piece, the mass part 30 g as the mass member is formed.
And a leaf spring portion 35g as an urging means are formed, so that the iron powder 30 as a mass member and the magnet 35 as an urging means are formed after the rotor core 11a is formed as in the first embodiment. , It is possible to save labor in manufacturing. However, in this embodiment, since the mass part 30g as a mass member is formed at the stage of forming the rotor core 11g, the dynamic balance of the rotor is measured after manufacturing the rotor, and based on this result, It is not possible to adjust the mass of the mass member.

Next, electric motors according to seventh and eighth embodiments of the present invention will be described with reference to FIGS. The above embodiments all relate to an induction motor,
The present invention is applied, for example, as shown in FIG. 11, a synchronous motor in which a permanent magnet 24h is attached to a rotor core 11h, or as shown in FIG.
The present invention can be applied to a DC motor or the like in which a coil 24i is applied to i. In any case, the magnet 24h or the coil 24i and the rotating shaft 25 are arranged so as not to interfere with the magnetic circuit formed in the rotor cores 11h and 11i.
It is preferable to provide spaces 19h and 19i between the two.

The present invention can be applied not only to a motor but also to a rotor of a generator. Electric motors convert electrical energy into mechanical energy.
The generator converts mechanical energy into electric energy in the opposite manner, and its basic structure is the same as that of the synchronous motor shown in FIG. Therefore, the present invention can be applied to any electric rotating machine whether it converts electric energy into mechanical energy or converts mechanical energy into electric energy.

[0037]

According to the present invention, when the electric rotating machine is stopped, the mass member is positioned on the rotating shaft side in the space of the rotor core, and when the electric rotating machine starts rotating, the mass member rotates. Since it is located on the outer peripheral side in the space of the child core, the moment of inertia of the rotor is small at the time of startup, and the moment of inertia of the rotor is large during rotation. Therefore, it can be easily rotated at the time of startup, and can be stably rotated during rotation.

In the case where a plurality of spaces are formed in the rotor core and mass members are put in each space, the dynamic balance of the rotor can be easily adjusted by adjusting the mass of each mass member. be able to.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an operation of a rotor of an electric motor as a first embodiment according to the present invention.

FIG. 2 is an explanatory diagram for explaining a moment of inertia.

FIG. 3 is a front view of an intermediate core piece of the electric motor according to the first embodiment of the present invention.

FIG. 4 is a front view of an end core piece of the electric motor according to the first embodiment of the present invention.

FIG. 5 is an exploded perspective view of a rotor core of the electric motor according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view of a rotor of a motor as a second embodiment according to the present invention.

FIG. 7 is an explanatory diagram showing a configuration of a rotor of an electric motor as a third embodiment according to the present invention.

FIG. 8 is a sectional view of a rotor of a motor as a fourth embodiment according to the present invention.

FIG. 9 is a sectional view of a rotor of a motor as a fifth embodiment according to the present invention.

FIG. 10 is a cross-sectional view of a rotor of a motor as a sixth embodiment according to the present invention.

FIG. 11 is a sectional view of a rotor of a motor as a seventh embodiment according to the present invention.

FIG. 12 is a sectional view of a rotor of an electric motor as an eighth embodiment according to the present invention.

FIG. 13 is a cutaway perspective view of a main part of the electric motor as the first embodiment according to the present invention.

FIG. 14 is a perspective view of a conventional cage rotor.

FIG. 15 is a perspective view of a conventional rotor core.

FIG. 16 is a perspective view of a conventional conductive cage.

[Explanation of symbols]

10, 10a ... rotor (rotor), 11, 11a, 11
b, 11c, 11d, 11e, 11g, 11h, 11i
... rotor core, 12 ... end core piece, 14 ... slot, 1
5 ... rotation shaft insertion hole, 16 ... middle part core piece, 17 ... opening,
19, 19b, 19d, 19e, 19g, 19h, 19
i: space, 21: conductor cage, 23: end ring, 2
4 bar, 25 rotating shaft, 30 iron powder, 30 d iron ball,
30g: mass part, 35, 35d: permanent magnet, 35c: coil, 35e: leaf spring, 35f: coil spring, 35g ...
Leaf spring part, 37: power supply circuit, 40: stator (stator), 45: casing.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiromichi Hiramatsu 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Hitachi, Ltd. Production Technology Research Institute (72) Noriaki Yamamoto 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Inside Hitachi, Ltd.Production Technology Laboratory (72) Inventor Takashi Ishigami 292, Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside Hitachi Ltd.Production Technology Laboratory (72) Inventor Motoya Ito 7-chome Omikacho, Hitachi City, Ibaraki Prefecture No. 1-1 Inside Hitachi, Ltd.Hitachi Research Laboratory (72) Inventor Fumio Tajima 1-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Inside Hitachi, Ltd.Hitachi Research Laboratory (72) Inventor Hirayoshi Kuwahara Tsuchiura, Ibaraki Prefecture 502 Kandate-cho, Machinery Research Laboratory, Hitachi, Ltd. (72) Inventor Yasuo Osone, Kandatsu, Tsuchiura-shi, Ibaraki 502 Nachi-machi Machinery Research Laboratory Co., Ltd. (72) Inventor Suetaro Shibukawa 2520 Oji Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi, Ltd.Automotive Equipment Division (72) Inventor Shoji Senoo 7-chome, Higashi Narashino, Narashino City, Chiba Prefecture No. 1 in the Industrial Equipment Division of Hitachi, Ltd.

Claims (8)

[Claims] 1. A rotor of an electric rotating machine in which a core is mounted around a rotation axis, wherein the core has a space extending from a rotation axis side close to the rotation axis to an outer periphery far from the rotation axis. Within, a mass member movable between the rotation shaft side and the outer peripheral side of the space, and a force smaller than a centrifugal force applied to the mass member at the time of rotation of a specific rotation speed or more, the mass member A biasing means for biasing from the outer peripheral side to the rotating shaft side, comprising: 2. The rotor of an electric rotating machine according to claim 1, wherein a plurality of said spaces are formed radially around said rotation axis in said core, and each of said plurality of spaces includes:
A rotor for an electric rotating machine, wherein the mass member is disposed. 3. The rotor of an electric rotating machine according to claim 2, wherein said rotating shaft and said core are respectively disposed in a plurality of said spaces so as to achieve a dynamic balance when rotating about said rotating shaft. A mass of the mass member to be adjusted is adjusted. 4. The electric rotating machine according to claim 1, wherein said mass member is a magnetic material, and said urging means is a permanent magnet. Rotor. 5. The rotor of an electric rotating machine according to claim 1, wherein the mass member is a magnetic material, the urging means includes a coil formed of a conductive material, and a coil formed of a conductive material. A power supply circuit for supplying a current to generate a magnetic field around the coil. 6. A rotor for an electric rotating machine according to claim 1, wherein said urging means is a spring for urging said mass member from said outer peripheral side to said rotating shaft side. And the rotor of the electric rotating machine. 7. The electric rotating machine according to claim 6, wherein the mass member and the spring are integral with each other and form a part of the core. Rotor. 8. The rotor of the electric rotating machine according to claim 1, 2, 3, 4, 5, 6, or 7, a stator disposed around the core of the rotor, and the rotor An electric rotating machine, comprising: a casing that covers the core and the stator of the rotor so as to be rotatable about the rotation axis.