JPS6219085Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an electric motor, specifically a rotor having a stator and a conductor made of a non-magnetic conductive material, a side rotor disposed outside the rotor in the axial direction within the magnetic field of the stator, and An electric motor comprising an actuating body provided axially outward of a side rotor, the actuating body being attracted to the side rotor by magnetic flux formed between the side rotor and the stator,
The purpose is to have a side rotor made of non-magnetic conductive material that can support not only each conductor of the rotor but also the iron core, and to serve as an end ring for each conductor to support each magnetic conductor buried in the side rotor. Even if the gap between the body and the rotor is small, it is possible to support the rotor and ensure a current-carrying cross-sectional area for each conductor, thereby efficiently generating suction force against the actuating body while making the entire body compact and lightweight. be able to,
The purpose is to provide an electric motor with low initial cost and low running cost.

In general, this type of motor has rotor conductors arranged around the outer circumference of the rotor core at equal intervals in the axial direction, and both ends of these conductors are short-circuited by end rings at both ends of the rotor core in the axial direction. The axial end surface of the side rotor is brought into contact with the end ring of the rotor to form a rotor, and the rotor and the side rotor are placed within the magnetic field of the stator. The magnetic flux formed therebetween is made to flow to the side rotor.

However, because the end rings are required to support each conductor of the rotor and to allow a large current to flow through them, the end rings are made thick, so that the magnetic flux that flows between them and the stator is limited to the side rotor. The stator cannot flow and leaks in the direction of the end ring, resulting in an unnecessarily long axial length of the stator, which increases running costs and increases overall external dimensions and weight. It was hot.

The present invention was devised in order to solve the above problems. One axial side of a rotor conductor made of a non-magnetic conductive material is extended in an annular shape, and an annular side rotor body is integrally provided on the conductor. The inner diameter of the side rotor main body is made to protrude radially inward from the conductor of the rotor, and the outer diameter of the side rotor main body is made to protrude radially outward by the conductor of the rotor. A plurality of magnetic bodies are buried at predetermined intervals in the inner circumferential direction with a gap between the conductor of the rotor and the axial end face of the iron core in the radial outer circumference, and these magnetic substances are embedded in the main body. An end ring is formed that is exposed on the outer peripheral surface and the end surface on the operating body side and blocks a magnetic path passing from the stator through the magnetic body and a magnetic path passing from the stator through the iron core of the rotor by the side rotor body. The rotor can be supported reliably by the rotor, and the distance between the opposing end surfaces of the magnetic material, rotor conductor, and rotor core can be made sufficiently small while still allowing the required large current to flow. This allows the magnetic flux to flow only through the side rotors without wasting it, shortens the length of the stator in the axial direction, and reduces the overall external dimensions and weight.

Embodiments of the present invention will be described in detail below based on the drawings.

In the figure, 1 is a substantially cylindrical electric motor yoke, 2 is a bracket fixed to both ends of the yoke 1 in the axial direction, and a stator iron core 3 is attached to the inner peripheral surface of the yoke 1.
A stator 5 consisting of a three-phase stator winding 4 wound around the iron core 3 is disposed around the stator 5, and a rotating shaft 7 is connected between the brackets 2 and 2 via bearings 6, 6.
is pivoted.

A squirrel cage rotor 8 and a side rotor 9 are fixed to the rotating shaft 7 at a position facing the inner peripheral surface of the stator 5, and a spline is formed at the end of the side rotor 9 on the opposite side from the rotor 8 side. Groove 10
is formed, and an actuating body 11 is provided so as to be slidably fitted into the groove 10.

The actuating body 11 is made of a magnetic material, and has a ring-shaped brake shoe 12 on the end surface opposite to the side rotor 9, and a spring 13 is provided between the side rotor 9 and the spring 13. 13, the actuating body 11 is constantly pressed in a direction away from the side rotor 9.

That is, this operating body 11 is connected to the rotating shaft 7 as described later.
When stopped, the brake shoe 12 is pressed against the bracket 2 by the spring 13, and is in a braking state, while when the rotary shaft 7 is driven, it moves toward the side rotor 9 against the pressing force of the spring 13, and the brake shoe 12 is pressed against the bracket 2 by the spring 13. The vehicle 12 is separated from the bracket 2 and is in a non-braking state.

What has been described above is a known three-phase squirrel-cage induction motor equipped with an internal brake, but the present invention provides a motor configured as described above, in which the side rotor main body 14 is made of a non-magnetic conductive material in the rotor 8. One side of the conductor 17 in the axial direction is formed by the conductor 17 extending annularly, and is integrally connected to the conductor 17 of the rotor 8. The outer diameter of the side rotor body 14 is made to protrude radially inwardly from the conductor 17 of the rotor 8. 17 and the axial end surface of the iron core 18.
A plurality of magnetic bodies 15 are buried at predetermined intervals in the circumferential direction, and these magnetic bodies 15 are exposed on the outer circumferential surface of the main body 14 and the end face on the side of the actuating body 11, and the stator 5 An end ring is formed to shield the magnetic path passing through the magnetic body 15 from the magnetic body 15 and the magnetic path passing from the stator 5 to the iron core 18 of the rotor 8. The conductor 17 of the rotor 8 and the main body 14 of the side rotor 9 are integrally molded by die-casting to form the gap 16 between the conductor 17 and the magnetic material 15. Specifically, the rotor core 18 is assembled by laminating silicon steel plates in advance, and the plurality of magnetic bodies 15 and the supports 19 for supporting the side rotor 9 of the rotating frame 7 are connected by a connecting body 23. The axial length of the support body 19 is made longer than the axial length of the magnetic body 15 by the width dimension B of the gap 16, and the rotor iron core 18 is formed into an integrally connected assembly. The support 1 on the outer surface
9 is placed in contact with the casting frame, and then a non-magnetic conductive material such as molten aluminum is poured into the casting frame.

Thus, by injecting the material, a conductor 17 is formed which connects the silicon steel plates in a laminated manner, as shown in FIG.
At the same time that the side rotor main body 14 is molded into one body, a gap 16 of the dimension B is simultaneously formed between the conductor 17 and the magnetic body 15.

Then, the primary product molded as described above is
The connecting body 23 and the excess conductive material are scraped off along the line A-A in the figure to expose the end face of the magnetic body 15, and the end face of the side rotor 14 is removed in the axial direction of the spring 13 as shown in FIG. An annular support groove 22 is formed to support the end portion, and the entire side rotor body 14 forms an end ring.

However, in the above configuration, the stator winding 4
When a predetermined voltage V ₁ is applied to the windings of the three phases, a current flows through each of the three-phase windings, and a rotating magnetic flux φm, which is a composite of the magnetic fluxes generated by the currents, is generated between the stator iron core 3 and the rotor iron core 18.
A rotating magnetic field is formed for each rotor conductor 17..., and the magnetic field induces a starting current in each rotor conductor 17, generating a starting torque, and the rotating shaft 7 starts rotating due to the starting torque. be.

Simultaneously with the activation of the rotating shaft 7, the magnetic flux φm from the stator core 3 flows into the side rotor 9, changes direction in the axial direction, flows into the actuating body 11, and circulates within the actuating body 11. Then, a magnetic circuit is formed that returns from the side rotor 9 to the stator core 3 again, and the magnetic flux φm flowing through this magnetic circuit generates an attractive force on the side rotor 9 in the actuating body 11, resisting the pressing force of the spring 13. The actuating body 11 is attracted to the side rotor 9 and the brake shoe 12 is brought into a non-braking state, allowing normal operation.

Moreover, when the voltage application to the stator winding 4 is cut off,
The magnetic circuit that had been formed from the stator 5 to the working body via the side rotor 9 disappears, and the working body 11
As the attraction force disappears, the actuating body 11 separates from the side rotor 9 due to the pressing force of the spring 13, and the brake shoe 12 is pressed by the bracket 2, and rotates only by inertia due to the disappearance of the rotating magnetic field. It performs a braking action on the rotating shaft 7.

In the above configuration, the side rotor 9 is designed to support not only the conductor 17 of the rotor 8 but also the iron core 18, so even if the dimension B of the gap 16 is small, the rotor 8 can be supported reliably, and
Since the entire conductive material forming the side rotor body 14 exhibits an end ring effect, even if the dimension B is sufficiently small, a large current flowing from each rotor conductor 17 can be easily received.

Therefore, the stator 5 can be formed to be shorter in the axial direction by an amount corresponding to the length made thinner than the thickness of the conventional end ring with the distance B, and the magnetic flux flowing between the stator 5 and the end ring can be made shorter than the thickness of the conventional end ring with the distance B. Only a very small amount leaks in this direction, and almost the entire amount flows through the magnetic bodies 15 of the side rotor 9 and can effectively contribute to the generation of the attractive force of the actuating body 11.

Further, since the rotor 8 and the side rotor 9 are integrally formed by die-casting, the number of parts is small, the number of man-hours can be reduced, and assembly can be carried out reliably and easily.

However, the attractive force applied to the actuating body 11 pulsates from the minimum zero value to the maximum value at a frequency twice as high as the frequency of the magnetic flux in response to changes in the alternating current magnetic flux flowing through the magnetic circuit. Although there is a problem in that the actuating body 11 vibrates due to the suction force in the pulsating state, this problem can be solved by the following configuration.

That is, the side rotor 9 has grooves 24 in the portions of the magnetic bodies 15 that are exposed on the side end surface of the actuating body 11.
is provided to divide the portion into two or more parts, and the same material as the conductive material constituting the side rotor body 14 is inserted into the groove 24, so that two or more small magnetic poles 25 are formed in the magnetic body 15. and each of these small magnetic poles 2
5 Shading coil 2 made of braking conductive material around...
This can be solved by forming 6.

Further, it is preferable to provide an even number of the magnetic bodies 15, and each small magnetic pole 25 formed on the magnetic body 15 is as follows:
A part of the magnetic flux φm from the stator 5 is transferred to each small magnetic pole 25.
Each magnetic flux φ2 is generated by circulating ..., but the phase and magnitude of each of these magnetic fluxes φ2 are divided and formed so that they differ from each other as necessary, as will be described later. 2 formed radially by a circumferential groove 24 of the book.
Of the two small magnetic poles 251 and 252, the magnetic fluxes φ21 and φ22 generated in the small magnetic pole 251 located radially outward and the small magnetic pole 252 located radially inward have the same magnitude and each phase. For example, each small magnetic pole 25
The ratio of the cross-sectional areas of 1 and 252 is changed to 1:2, 1:3, or the inverse of these ratios, and in this way, what kind of small magnetic pole 25 is formed by the groove 24? Whether this is the case will become clear from the following explanation.

In the above configuration, when a predetermined three-phase primary voltage V ₁ is applied to the three-phase stator winding 4, a magnetic flux φm that is a composite of each magnetic flux generated by the primary load current I' ₁ flowing through each winding 4 is generated. A part of it flows into each magnetic body 15, flows into the actuating body 11 from the small magnetic poles 25, circulates within the actuating body 11, and then flows again from the small magnetic poles 25... into the magnetic bodies 15... A large number of magnetic circuits returning to the stator 3 are formed.

These primary voltage V ₁ , primary load current I′ ₁ , magnetic flux φ
As shown in Fig. 4, the magnetic flux φm lags the primary voltage V ₁ by 90°, and the primary load current I′ ₁ is closer to the primary voltage V ₁ between this magnetic flux φm and the primary voltage V ₁ . An excitation current I ₀ is located at a position slightly advanced from the magnetic flux φm, and the sum of this excitation current I ₀ and the primary load current I' ₀ forms a primary current I ₁ .

When this magnetic flux φm passes through each small magnetic pole 25, a secondary induced electromotive force _E2 is induced in the shaded coil 26 in the opposite direction to the primary voltage _V1 , and the electromotive force
Due to the secondary current I ₂ which lags behind E ₂ , various magnetic fluxes φ2 are generated as if the circuit is closed through the two small magnetic poles 25, 25 which are adjacent to each other, and are superimposed on the magnetic flux φm.

Note that R is the resistance of the shaded coil 26, and X is the reactance of the shaded coil 26.

As described above, between the small magnetic pole 25 and the actuating body 11, the magnetic flux φm is unevenly distributed by a predetermined phase angle α with respect to each other, and both have a phase angle with respect to the magnetic flux φm.
The magnetic fluxes φ21 and φ shifted by β and γ close to 90°
22 flow superimposed on each other, the actuating body 11 receives an attractive force corresponding to the magnetic flux φm.
Fm and the attractive force F2 corresponding to the magnetic flux φ21, φ22
1 and F22 come into play. That is, these attractive forces Fm, F21, F22 pulsate from the minimum zero value to the maximum value according to the magnitude of the absolute value of the magnetic flux φm and the magnetic fluxes φ21, φ22, respectively, and as shown in FIG. As shown in FIG. Therefore, the pulsation of the actuating body 11 against the vibration can be made sufficiently small, and the noise caused by the vibration can be eliminated.

What has been described above is a case where the end surface of each magnetic body 15 on the side of the actuating body 11 is divided into two small magnetic poles 251 and 252 by one radial groove 24. 15 working bodies 1
By dividing the first side end face into arbitrary shapes and numbers of grooves 24 of arbitrary shapes, the waveform of the total suction force F to the actuating body 11 can be reliably made to have a small pulsation rate, and the total suction force Since the frequency of F can be greatly increased, by adjusting the magnitude of the frequency, it is possible to reliably eliminate vibrations of the actuating body 11 and eliminate noise.

Furthermore, circumferential grooves 24 are provided in each of the magnetic bodies 15 exposed on the side end surface of the actuating body 11 to divide the exposed portions of each of the magnetic bodies 15.
A plurality of small magnetic poles 25 are formed around each small magnetic pole 25, and a shaded coil 2 made of the conductive material is formed around each of these small magnetic poles 25.
By forming the annular groove 27 in the circumferential direction at a position facing the groove 24 in the actuating body 11, the noise caused by the vibration of the actuating body 11 can be further reduced as described above.

That is, in each of the small magnetic poles 25, the radially outer small magnetic pole 251 and the radially inner small magnetic pole 252 exhibit opposite magnetism, as shown in FIG.
and adjacent small magnetic poles 251, 251 and 252, 2
52 exhibit mutually opposite magnetism, and there are four magnetic paths between the four small magnetic poles 25, 25 of the adjacent magnetic bodies 15, 15, that is, a small magnetic pole 251 and a small magnetic pole 251 for each magnetic body 15. Magnetic paths M1, M2 in opposite directions formed between the small magnetic pole 252 and magnetic paths M3, M4 in opposite directions formed in the adjacent small magnetic poles 251, 251 and 252, 252, respectively.
is formed astride within the actuating body 11.

Since each portion of the actuating body 11 facing the small magnetic poles 251 and 252 is separated by the annular groove 27, each portion clearly has magnetism opposite to that of the small magnetic poles 251 and 252. Therefore, among the four magnetic paths M1 to M4, the magnetic paths M1 and M that pass through the small magnetic poles 251 and 252
2 is clearly formed, and each magnetic path M1,
The magnetic flux passing through M2 can contribute sufficiently and effectively to the generation of the total attractive force F of the actuating body 11 to the side rotor 9 without any waste. Moreover, the adjacent small magnetic poles 251,
Actuator 11 facing 251, 252, 252
As described above, each part of these small magnetic poles 251, 2
Since the magnetism opposite to that of 52 is clearly generated, magnetic paths M3 and M4 are similarly clearly formed, and the magnetic flux passing through each of these magnetic paths M1 and M2 is also efficiently transferred to the side rotor 9 of the actuating body 11. This can contribute sufficiently effectively to the generation of the total suction force F against the force.

In this way, the magnetic flux passing through each small magnetic pole 25 effectively circulates so as to generate the total attractive force F, so that the amount of magnetic flux m generated in the stator 5 taken out to the side rotor 9 side can be reduced, and the amount of magnetic flux flowing through the side rotor 9 can be reduced. 9 or the operating body 11 can be made smaller and lighter, and therefore the side rotor 9 can be made smaller and lighter.
In combination with the fact that the pulsation rate of the total suction force F has been made sufficiently small, the vibration of the actuating body 11 can be made sufficiently small, and the noise caused by the vibration of the actuating body 11 can be reliably eliminated. .

Furthermore, by forming the width of the portion of the magnetic body 15 exposed on the stator 5 side in a shape that widens from the rotor side toward the side rotor 9 side, leakage of magnetic flux toward the end ring 11 side can be reduced and the width of the side rotor 9 can be reduced. The flow of magnetic flux to the side can be increased, and the total attractive force F can be further increased.

In the above explanation, however, the present invention is applied to a three-phase squirrel-cage induction motor, but it can be applied to various types of motors, including wound-type induction motors and synchronous motors, regardless of the number of phases.

In addition, although the above description has been made regarding the case where the brake is actuated by the movement of the actuating body, the same applies to the case where the clutch is actuated.

As described above, according to the present invention, the side rotor main body is integrally formed with the rotor conductor by extending one axial side of the rotor conductor into an annular shape, and the inner diameter of the side rotor main body is adjusted to the inner diameter of the rotor. An end ring is formed by making the outer diameter of the side rotor main body protrude radially inward from the conductor and located at the end of the conductor of the rotor protrude radially outward from the conductor of the rotor. Since the magnetic material provided on the side rotor main body and the rotor iron core of the rotor are separated by the entire rotor main body, the width of the gap between the rotor and each magnetic material, the so-called end ring, is minimized. It can be shortened to a minimum, and the magnetic path passing from the stator through the magnetism and the magnetic path passing from the stator through the iron core of the rotor can be reliably blocked, and the magnetic flux from the stator is not leaked wastefully into the gap. It is efficiently circulated throughout the entire body through each magnetic body to the actuating body, and together with the fact that each magnetic body is exposed on the outer circumferential surface of the main body and the end face on the side of the actuating body, a large attractive force is exerted on the actuating body. It can be generated efficiently and both initial cost and running cost can be reduced.

Moreover, even if the size of the gap is reduced, the conductor of the rotor and the side rotor main body are integrally formed, so that the required current-carrying cross-sectional area of the end ring can be sufficiently secured.

Moreover, no matter how small the gap size between the rotor and the magnetic material, the rotor iron core can be supported by the radially inward protrusion of the side rotor. The entire axial length of the shaft can be shortened, and it can be formed lightweight and inexpensively.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional explanatory diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of a primary product made by die-casting a side rotor and a rotor, Fig. 3 is a side view of the side rotor on the side of the actuating body, and Fig. 4 5 is a vector diagram, FIG. 5 is an explanatory diagram of the waveform of the attractive force, and FIG. 6 is an explanatory diagram of the magnetic path. 8...Rotor, 9...Side rotor, 14...
Side rotor body, 15... Magnetic material, 16... End ring, 17... Rotor conductor, 18... Rotor iron core.

Claims (1)

[Scope of utility model registration request] It consists of a rotor having a stator and a conductor made of a non-magnetic conductive material, a side rotor disposed outside the rotor in the axial direction within the magnetic field of the stator, and an actuating body provided outside the side rotor in the axial direction. , in an electric motor in which the actuating body is attracted to the side rotor by magnetic flux formed between the conductor and the stator, one axial side of the conductor is extended in an annular shape, and an annular side rotor body is integrally provided on the conductor. The inner diameter of the side rotor main body is made to protrude radially inward from the conductor of the rotor, and the outer diameter of the side rotor main body is made to protrude radially outward from the conductor of the rotor.
A plurality of magnetic bodies are buried at predetermined intervals in the circumferential direction, with gaps between the conductor of the rotor and the axial end face of the iron core, in the radial outer circumference of the main body, and these magnetic bodies is exposed on the outer circumferential surface of the main body and the end surface on the operating body side, and the side rotor main body blocks a magnetic path passing from the stator through the magnetic body and a magnetic path passing from the stator through the iron core of the rotor. An electric motor characterized by forming a ring.