JPH07303358A - Rotor for self-excited generator - Google Patents

Abstract

PURPOSE:To suppress the vibration of a stator so as to prevent the generation of abnormal sounds. CONSTITUTION:A stator 61 is formed by housing an output winding and capacitor winding in a plurality of slots 62 arranged on the inner periphery of the stator 61 and a rotor 70 is provided with a field winding Wf and, at the same time, permanent magnets 78 are arranged on the side face of the rotator 70 on both sides of the center of rotation of the rotor 70. The magnets 78 are shifted from 180 deg. symmetrical positions with respect to the center of rotation of the rotor 70 so that one magnet 78 can be positioned to the middle of adjacent slots 62 when the other magnet 78 comes to face one of the slots 62.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a self-excited generator used for a portable generator and the like and a rotor thereof.

[0002]

2. Description of the Related Art Conventionally, a self-excited generator having a structure shown in FIGS. 21 to 23 has been known. The self-excited generator shown in these figures has the output winding We to which the load L is connected.
And a capacitor excitation winding Wc, which is wound around the same iron core as the output winding We and has a capacitor C connected to both ends, is provided in the stator S, and a field winding Wf is wound around the rotor R. A rectifier D is connected to both ends of the field winding Wf for a schematic configuration. Here, on both sides of the rotor R, permanent magnets M having the same polarity as that of the rotor core R are mounted on the opposite sides of 180 °. Further, in FIG. 21, reference numeral S
l is a slot, and the output winding We
And the capacitor excitation winding Wc. As shown in FIG. 22, the output winding We and the capacitor exciting winding Wc are wound so that their magnetic centers are orthogonal to each other. The output winding We is wound around slots # 7 to # 32 and slots # 14 to # 25, and the capacitor excitation winding Wc
Are wound around slots # 8 to # 13 and slots # 31 to # 26.

In the above self-excited generator, the rotor R
When the rotor starts rotating, the residual magnetism of the rotor R generates a voltage in the capacitor exciting winding Wc, and this voltage is applied to the capacitor C, whereby the capacitor exciting winding Wc
A phase-advancing current flows through. A self-excitation phenomenon occurs due to the magnetizing action of the phase-advancing current, and magnetism is generated in the capacitor excitation winding Wc. Next, the field winding W of the rotor R is generated by this magnetism.
A voltage is generated in f, this voltage is rectified by the rectifier D and flows into the field winding Wf, and the rotor R is made into a strong magnet so that it can generate electricity. When the rotor R is magnetized, the voltage of the output winding We and the voltage of the capacitor exciting winding Wc rapidly increase,
Voltage required for rated rotation of rotor R (for example, 100V)
To occur.

In the power generation operation as described above, the permanent magnet M has a function of improving the rise of the initial output voltage of the generator, and the permanent magnet M generates a voltage at a lower rotation speed. You can do it.

[0005]

By the way, in the self-excited generator having the above-mentioned structure, as shown in FIG. 13, the magnetic resistance rapidly increases in the central portion of the slot of the stator, and the magnetic resistance is fixed accordingly. The strength of the magnetic force directed to the child becomes smaller.
On the other hand, since the permanent magnet itself of the rotor also has a high magnetic resistance, when the permanent magnet passes through the slot, the overall magnetic resistance becomes the magnetic resistance of the slot plus the magnetic resistance of the permanent magnet. However, in the rotor having the above structure, since the two permanent magnets pass in front of the slots at the same time, the overall magnetic resistance at that time is 2 times the magnetic resistance of the two slots.
It is the sum of the magnetic resistance of two permanent magnets. As described above, in the conventional rotor, the change in the value of the magnetic resistance is large, and as a result, the change in the magnetic force directed to the stator is large, and the period of such a change in the magnetic force is the resonance frequency of the stator. When they are equal, there is a problem that the stator vibrates and emits an abnormal noise.

The present invention has been made in order to solve the above problems, and it is possible to suppress the vibration of the stator and thus prevent the generation of abnormal noise. And to provide its rotor.

[0007]

A rotor according to claim 1 is a rotor for a self-excited generator rotatably disposed inside a stator, wherein the stator has an inner peripheral portion. The output winding and the capacitor winding are housed in the slots provided in an even number side by side in the circumferential direction, and the rotor is
In a rotor for a self-excited generator in which a field winding is provided and permanent magnets are arranged on both sides of the rotation center, the permanent magnet is displaced from a symmetrical position of 180 ° with respect to the rotation center. It is characterized in that when one of the permanent magnets faces one of the slots, the other permanent magnet is arranged in the middle of the adjacent slots.

A rotor according to a second aspect of the present invention is characterized in that the permanent magnet is displaced from a symmetrical position of 180 ° with respect to the rotation center by half the pitch of the slots in the circumferential direction.

[0009]

In the rotor according to the present invention, when one of the permanent magnets passes through one of the slots, the other permanent magnet passes through the middle of the slots having a small magnetic resistance. , The change in overall magnetic resistance is mitigated. Thereby, the influence of the change in the magnetic force on the stator is reduced, and the vibration of the stator is suppressed.

In the rotor according to the second aspect, since the permanent magnets are arranged near the symmetrical position of 180 ° with respect to the center of rotation, it has a sufficient function of improving the rise of the initial output voltage of the generator. Can be demonstrated.

[0011]

【Example】

(1) Structure An embodiment of the present invention will be described below with reference to FIGS. 1 to 19. The embodiments described below apply the present invention to a rotor for a portable generator. Therefore, first, the schematic configuration of the portable generator will be described with reference to FIGS.

A. Configuration of Portable Generator In FIG. 1, reference numeral 20 is a frame. Frame 20
Is formed by combining an upper pipe 21 and a lower pipe 22 having a U-shape in a substantially rectangular appearance. A rod-shaped support 23 is erected between the lower parts of the lower pipes 22 and 22, and the support 23 is mounted on the support 23 via a bracket 24.
A cycle engine (internal combustion engine, hereinafter abbreviated as “engine”) 25 is attached. In addition, reference numeral 2 in the drawing
6 is an air cleaner, 27 is a fuel tank, 28 is a muffler cover, and 29 is a muffler. Further, in FIG. 1, reference numeral 30 is a handle of the recoil starter, and when the handle 30 is pulled out, the crankshaft is rotated and the engine 25 is started.

In addition, the support 23 of the frame 20 includes
A generator 31 having a rotor (not shown) coaxially connected to the crankshaft of the engine 25 is attached via a bracket 24. In FIG. 4, reference numeral 32 is a socket 33 and switches 34 and 35.
Is a control box in which is arranged, and 36 is a cover of a cooling fan.

Next, in the upper pipe 21, the fuel tank 2
A protect frame 40 for protecting 7 is detachably attached. The protect frame 40 has a pipe shape and is attached to the upper pipe 21 by a pair of saddles 41 and 42 at both ends thereof, as shown in FIGS. Each saddle 41, 42 has an inner peripheral surface that is in close contact with the outer peripheral surfaces of the protect frame 40 and the upper pipe 21 that are arranged orthogonally. Further, a laterally long hole 41a is formed at the tip of one saddle 41.
In a, the hook portion 4 formed at the tip of the other saddle 42.
2a is engaged. Further, both side portions of the saddles 41 and 42 are fastened with bolts 43 and nuts 44, whereby the protect frame 40 and the upper pipe 21 are fixed to each other.

B. Configuration of Generator Next, a schematic configuration of a generator 31 using the rotor of the embodiment will be described with reference to FIGS. 9 and 10. In the figure, reference numeral 50 is a frame that constitutes the outer shell of the first half of the generator, and the remaining outer shell is the frame 5
The cover 51 arranged at the rear end of the
It is constituted by a crankcase cover 52 of the engine 25 arranged at the rear end portion. The crankcase cover 52 is attached to the rear end of the frame 50 with bolts 53, and the cover 51 is sandwiched between the frame 50 and the crankcase cover 52. An X-shaped support 54 is formed on the front surface of the frame 50, and a bearing 55 is attached to the center of the support 54. Further, on the front surface of the frame 50, a cover 5 for hiding the inside is provided.
6 is attached. For convenience of explanation, FIG. 9 shows a state in which the cover 56 is removed.

A stator assembly 60 is mounted inside the frame 50. In FIG. 11, reference numeral 61 is a stator (stator). The stator 61 has a substantially ring shape, and a plurality of slots of the same shape and size (36 in this embodiment) extending in the axial direction are formed on the inner peripheral surface of the stator 61.
2 are formed at equal intervals in the circumferential direction. Each slot 6
Inside 2, a capacitor excitation winding Wc and an output winding We are housed. The capacitor excitation winding Wc
The details of the output winding We will be described later.

Next, reference numeral 70 in the figure denotes a rotor assembly (rotor). A shaft 71 is attached to the center of the rotor assembly 70, and the tip of the shaft 71 is rotatably supported by a bearing 55. A crankshaft (not shown) of the engine 25 is connected to the rear end of the shaft 71, whereby the rotor assembly 70 is rotatably supported. Incidentally, reference numeral 72 in the drawing
Is a cooling fan.

FIG. 11 shows details of the rotor assembly 70. In the figure, reference numeral 73 is a core. The core 73 is
It is configured by laminating a plurality of electromagnetic steel sheets having a planar shape shown in the figure. On the side of the core 73, four extending in the axial direction
One groove 74 is formed in line symmetry. Groove 74
A bobbin 75 protruding in the axial direction is fitted in the shaft. The bobbin 75 is made of synthetic resin and has a U-shaped cross section, and the field winding Wf is housed therein. The field winding Wf is configured by winding the winding around the left and right bobbins 75. Also, the core 73
Of the cylindrical curved surface of the groove 7 extending in the axial direction thereof.
7, the permanent magnet 78 having the polarity shown in FIG. 11 is fitted in the groove 77.

As shown in FIG. 12, the positions of the grooves 77 are displaced from each other by an angle θ with respect to the axis of symmetry of the core 73. As a result, when one permanent magnet 78 is located in front of the slot 62, the other permanent magnet 78 is located in the center of two adjacent slots 62. And
Due to this structure, the deviation angle θ of the groove 77 is set to ¼ of the central angle formed by the adjacent slots 62. Therefore, in this embodiment, the number of slots 62 is 36.
Therefore, the central angle is 10 °, so θ is 2.5.
It is said to be °. In FIG. 10, reference numeral 79 is a stopper for the permanent magnet 78, and the stopper 79 is formed integrally with the bobbin 75. A rectifier and the like are housed inside the bobbin 75. Further, for convenience of description, the rotor assembly 70 is omitted in FIG. 9.

C. Other Configuration of Generator Next, FIG. 15 shows a capacitor excitation winding Wc and an output winding We.
It is a figure for explaining how to wind. The capacitor excitation winding Wc has slots # 9 to # 13 and slots # 27 to #.
One winding is wound by using 31. That is, the winding is wound in slots # 9 and # 31 and then in slots # 10 and # 30.
In this manner, the slots # 13 and # 27 are sequentially wound.

The output winding We has slots # 7 to #.
One winding is wound using 32 and slots # 14 to # 25. That is, the winding is wound in slots # 7 and # 14, and then in slot # 6.
And wound around # 15. In this way, slot # 3
2 and # 25 are sequentially wound.

Here, empty slots # 8 and # 26 in which the winding is not wound are provided between the capacitor exciting winding Wc and the output winding We. Empty slot #
The positions of 8 and # 26 are in the middle of reaching from the capacitor excitation winding Wc to the output winding We in the direction in which the rotor assembly 70 rotates. As a result, the magnetic center of the capacitor excitation winding Wc is 90 ° and 1/2 slot with respect to the magnetic center of the output winding We, that is, 5
Deviated.

18 and 19 show a duct 90 which connects the generator 31 and the control box 32 and through which a wire harness is passed. Duct 90
Connects the first grommet 91 attached between the frame 50 of the generator 31 and the cover 56, the second grommet 92 attached to the control box 32, and the first and second grommets 91, 92 to each other. It consists of a corrugated tube 93. The corrugated tube 93 is made of a slightly rigid material, and a plurality of annular grooves 93a are formed on the outer peripheral portion thereof.

On the other hand, the first and second grommets 91, 92
Is made of an elastic material such as rubber, and the generator 31
Alternatively, the mounting holes 31a, 32 of the control box 32
By tightly fitting a, the waterproof state is secured. Further, a plurality of annular ribs 91a, 92a that fit with the annular groove 93a are formed on the inner circumferences of the free ends of the first and second grommets 91, 92. The corrugated tube 93 is connected to the first and second grommets 91 and 92 by fitting the annular groove 93a into the annular ribs 91a and 92a of the first and second grommets 91 and 92.

(2) Operation and effect of the embodiment Next, the operation of the embodiment will be described. First, to start the engine, handle the recoil starter handle 30.
(See Fig. 1) Hold by hand and pull vigorously. As a result, the engine 25 starts and the rotor assembly 70 rotates. Then, according to the same principle as the conventional self-excited generator, a required voltage is generated when the rotor assembly 70 reaches the rated rotation time. At that time, the magnetic force of the permanent magnet 78 is added to the magnetic force due to the residual magnetism generated from the core 73, the rise of the initial output voltage is improved, and the voltage is generated at a lower rotation speed of the rotor assembly 70.

In the self-excited generator having the above structure,
Because the permanent magnets 78 are arranged offset from the axis of symmetry passing through the center of rotation of the rotary assembly 70, when one of the permanent magnets 78 passes through one of the slots 62 as shown in FIG. Since the permanent magnet 78 passes through the middle of the slots 62 having a small magnetic resistance, the change in the overall magnetic resistance is moderated. This reduces the influence of the change in the magnetic force on the stator assembly 60, and suppresses the vibration of the stator assembly 60.

In the generator having the above structure, the magnetic center of the capacitor exciting winding Wc is 90 ° and 1/2 slot with respect to the magnetic center of the output winding We, that is, 5 slots.
Deviated. As a result, as shown by arrow A in FIG. 16, the output terminal voltage with respect to the load current becomes higher than in the conventional case (indicated by arrow B in the figure). As a result, as indicated by arrow A in FIG. 17, the generated voltage rises at a lower rotation speed than in the conventional case (indicated by arrow B). Therefore, the engine 25 for rotating the rotor assembly 70
Can be miniaturized, and the generator can be miniaturized. Here, such an effect is obtained at an angular position where the combined magnetic field obtained by combining the magnetic field generated by the output current and the magnetic field generated by the current flowing through the field winding Wf is maximum. This is because the capacitor excitation winding Wc is wound.

Further, in the generator having the above structure, the generator 31 and the first grommet 91, and the control box 32 and the second grommet 92 are connected in a waterproof state. Also, the first and second grommets 91, 9
2 and the corrugated tube 93, the annular groove 93a and the annular ribs 91a and 92a form a labyrinth structure, so that water is hard to enter. Therefore, such a duct can greatly improve the waterproof performance.

Incidentally, an example of a conventional duct structure is shown in FIG. In the duct 100 shown in this figure, the first grommet 101 is attached to the generator 31, the second grommet 102 is attached to the control box 32,
A wire harness (not shown) covered with a tube 103 is provided between the first and second grommets 101 and 102. In such a duct structure, there is a drawback that water easily enters through the gap between the tube 103 and the first and second grommets 101 and 102, and the waterproof property is not sufficient. Further, there is a drawback that the strength and the appearance are not sufficient because the tube 103 has no rigidity. on the other hand,
In order to improve waterproofness, it is possible to integrally mold the first and second grommets and the tube, but the complicated shape makes the manufacturing cost more expensive and changes the distance between the first and second grommets. There is a new problem that it cannot be done and is not versatile.

In this respect, the duct 90 in the above embodiment is divided into three parts, so that the structure is simplified,
The assembly is simple and the manufacturing cost can be reduced. Furthermore, since the corrugated tube 93 can be made of a material having high rigidity, the strength is improved, and moreover,
Since the generator 31 and the control box 32 are connected by the corrugated tube 93 having high rigidity, the appearance is improved. Further, since the length of the corrugated tube 93 can be adjusted by appropriately cutting it, the corrugated tube 93 can be applied to various types of power generators.

(3) Modified Example FIG. 14 is a view showing a modified example of the core 73 which constitutes the rotary rear assembly 70 of the present invention. Core 7 shown in this figure
3 has a groove 77 for accommodating the permanent magnet 78,
It is arranged by being shifted by 3θ with respect to the axis of symmetry of 3.
As a result, when one of the permanent magnets 78 faces the slot 62, the other permanent magnet is displaced by 1.5 slot pitch and comes to the position of point P1 in FIG. Such a core 7
Even if 3 is used, the same effect as that of the above embodiment can be obtained. The other permanent magnet may be located at the point P2 or P3 in FIG.

Further, in the above embodiment, the magnetic center of the capacitor excitation winding Wc is set 90 degrees in the direction opposite to the rotational direction of the rotor assembly 70 with respect to the magnetic center of the output winding We.
゜ and ½ slot, that is, 5 degrees offset,
It may be offset by 90 ° and 1.5 slots or 2.5 slots. Further, although the present invention is applied to the capacitor self-exciting generator in the above-described embodiment, it can be applied to an AVR self-exciting generator having an automatic voltage adjusting circuit.

[0033]

As described above, according to the present invention, it is possible to suppress the vibration of the stator, and thus, it is possible to prevent the generation of abnormal noise.

[Brief description of drawings]

FIG. 1 is a front view showing a portable generator to which the present invention is applied.

FIG. 2 is a view on arrow II in FIG.

FIG. 3 is a view in the direction of arrow III in FIG.

FIG. 4 is a view in the IV direction of FIG.

5 is a view in the direction V of FIG.

6 is a view in the direction of arrow VI in FIG.

7 is a sectional view taken along line VII-VII of FIG.

8 is a sectional view taken along line VIII-VIII of FIG.

FIG. 9 is a front view showing the self-excited generator of the embodiment.

FIG. 10 is a side sectional view of the self-excited generator of the embodiment.

FIG. 11 is an axial cross-sectional view showing the arrangement of a rotor assembly and a stator assembly.

FIG. 12 is a plan view showing a core.

FIG. 13 is a diagram for explaining the arrangement of permanent magnets.

FIG. 14 is a plan view showing a modified example of the core.

FIG. 15 is a plan view for explaining windings of the stator assembly of the embodiment.

FIG. 16 is a diagram showing a relationship between load current and output terminal voltage.

FIG. 17 is a diagram showing the relationship between the rotation speed of the rotor and the output terminal voltage.

FIG. 18 is a side sectional view showing details of a duct through which a wire harness is passed.

FIG. 19 is a vertical sectional view showing a corrugated tube.

FIG. 20 is a vertical cross-sectional view showing a conventional duct structure.

FIG. 21 is an axial cross-sectional view showing the arrangement of a conventional rotor assembly and stator assembly.

FIG. 22 is a plan view for explaining a winding wire of a conventional stator assembly.

FIG. 23 is a diagram for explaining the principle of a self-excited generator.

[Explanation of symbols]

 61 ... Stator (stator), 62 ... Slot, 70 ... Rotor assembly (rotor), 78 ... Permanent magnet We ... Output winding, Wc ... Capacitor winding Wf ... Field winding.

Claims (2)

[Claims] 1. A rotor for a self-excited generator that is rotatably arranged inside a stator, wherein the stator has an even number of slots provided in an inner peripheral portion thereof in a circumferential direction. For a self-excited generator in which an output winding and a capacitor winding are housed, the rotor is provided with a field winding, and permanent magnets are arranged on both sides of the center of rotation. In the rotor, the permanent magnet is arranged so as to be displaced from a symmetrical position of 180 ° with respect to the center of rotation, and
Rotation for a self-excited generator, characterized in that when one permanent magnet faces one of the slots, the other permanent magnet is arranged in the middle of the adjacent slots. Child. 2. The self-excited power generation according to claim 1, wherein the permanent magnet is displaced from a symmetrical position of 180 ° with respect to the center of rotation by half the pitch in the circumferential direction of the slot. Rotor for machine.