JP2006020464A - Wind power generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new technique optimizing the start torque of a generator in a wind power generator. <P>SOLUTION: In a generator of the wind power generator, a rotor and a stator are axially positioned so that at least either the rotor 72 or the stator 70 has projections 80, 84 axially projecting from the opposite direction and has opposite portions 82, 86 radially facing the opposite direction. Furthermore, the wind power generator includes changing mechanisms 110, 130 which support the rotor and the stator relatively so as to be axially movable, and selectively changes the relative position in the axial direction of the rotor and the stator between a first state where both the projections and the facing portions exist, and a second state where axial lengths of the projections are shorter than that in the first state and axial lengths of the facing portions are longer than that in the first state. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wind turbine generator, and more particularly, to a technique for optimizing a starting torque of a generator in the wind turbine generator.

  A wind turbine generator is generally configured to include a windmill that rotates by receiving wind, a shaft that rotates together with the windmill, and a generator that generates power by being driven by the shaft. In the generator, the rotor and the stator are relatively positioned in the axial direction.

  In this type of wind power generator, in order for the windmill to shift from the stopped state to the rotating state, it is necessary that the torque generated in the windmill by the wind overcomes the starting torque. The main factor that generates the starting torque is the generator. Therefore, in the wind power generator, it is effective to reduce the starting torque of the generator in order to start the windmill smoothly during a light wind.

Patent Document 1 discloses a technique for preventing a field current from being supplied to a field winding of a generator until the actual rotation speed of the generator reaches a preset power generation start rotation speed in a wind turbine generator. It is disclosed. If this technology is implemented, in the region where the actual rotational speed of the generator is less than or equal to the power generation start rotational speed, that is, in the light wind region, the loss of the generator is mainly only mechanical loss, and the starting torque of the generator is reduced. Therefore, the windmill can be started smoothly.
JP-A-62-58061

  The present inventor has studied a technique for reducing the starting torque of the generator without controlling the field current. As a result, when the present inventors position the rotor in the axial direction relative to the stator in the generator, the stator projects in the axial direction from the rotor as well as the facing portion that faces the rotor in the radial direction. It has been found that the positioning torque is reduced so that the starting torque is reduced as compared with the case where the positioning is performed so that the protruding portion does not exist.

  Further, the present inventor controls the starting torque of the generator by the relative movement of the rotor and the stator in the axial direction, and mechanically utilizes the axial force generated on the shaft by the windmill, so that the axial direction of the rotor and the stator We studied the technology to realize relative movement. As a result, the present inventor has devised a novel structure in which the axial relative position between the rotor and the stator is mechanically changed by the axial force of the shaft in response to wind force.

  With the background described above as a background, the present invention has been made to propose a new technique for optimizing the starting torque of a generator in a wind turbine generator.

  The following aspects are obtained by the present invention. Each aspect is divided into sections, each section is given a number, and is described in a form that cites other section numbers as necessary. This is to facilitate understanding of some of the technical features that the present invention can employ and combinations thereof, and the technical features that can be employed by the present invention and combinations thereof are limited to the following embodiments. Should not be interpreted. That is, it should be construed that it is not impeded to appropriately extract and employ the technical features described in the present specification as technical features of the present invention although they are not described in the following embodiments.

  Further, describing each section in the form of quoting the numbers of the other sections does not necessarily prevent the technical features described in each section from being separated from the technical features described in the other sections. It should not be construed as meaning, but it should be construed that the technical features described in each section can be appropriately made independent depending on the nature.

(1) A wind power generator that generates power using wind power,
A windmill that rotates in response to the wind,
A shaft that rotates with the windmill,
A generator for generating electricity by being driven by the shaft, and the generator
A rotor that rotates together with the shaft and a stator, and at least one of the rotor and the stator has a facing portion that faces the opponent in the radial direction and a protruding portion that protrudes in the axial direction from the opponent. Wind power generator.

  In this wind power generator, in the generator, at least one of the rotor and the stator has a protruding portion that protrudes in the axial direction from the counterpart, and a facing portion that faces the counterpart in the radial direction. The rotor and the stator are positioned in the axial direction.

  The following knowledge was obtained by the inventor's research. That is, when a protrusion is present on at least one of the rotor and the stator, a leakage magnetic flux is likely to be generated between the rotor and the stator in a direction not perpendicular to the rotation axis of the rotor, compared to the case where there is no protrusion. As a result, they have found that the field magnetic flux tends to decrease. According to this knowledge, when the protrusion is present, the starting torque of the generator is reduced as compared with the case where the protrusion is not present.

  Based on the knowledge explained above, in the wind turbine generator according to this section, the rotor and the stator are relatively positioned in the axial direction so as to have the above-described protrusion.

  In this wind power generator, it is not indispensable to implement the generator in such a manner that each of the rotor and the stator has both the protruding portion and the facing portion. The rotor has both a protruding portion and a facing portion, while the stator has only the facing portion, or the rotor has only the facing portion, while the stator has both a protruding portion and a facing portion. It is also possible to do.

  Further, in this wind turbine generator, the rotor and the stator are designed to be opposed to each other in the radial direction with an air gap having a shape extending in the axial direction in the same circular cross section, or the diameter of the circular cross section. Can be designed to face each other in the radial direction with an air gap having a shape that changes as the shaft advances in the axial direction.

  Furthermore, in this wind turbine generator, the generator can be implemented in such a manner that the axial relative position between the rotor and the stator can be changed, or the generator can be implemented in such a manner that the axial relative position is fixed. Is possible.

(2) Further, the rotor and the stator are supported so as to be relatively movable in the axial direction, and the relative position in the axial direction between the rotor and the stator is determined so that both the protruding portion and the facing portion exist. 1 and the axial length of the projecting portion is selectively shorter than the first state, and the axial length of the facing portion is selectively changed to a second state longer than the first state. The wind power generator according to item (1), including a changing mechanism.

  According to this wind power generator, the starting torque of the generator is changed by selectively changing the axial relative position between the rotor and the stator between the first state and the second state. Therefore, according to this wind power generator, it is possible to control the starting torque so as to adapt to changes in the environment.

(3) When receiving wind, the windmill generates axial force and rotational force on the shaft,
The said change mechanism is a wind power generator as described in (2) term which changes the said axial relative position using the axial force generate | occur | produced in the said shaft by the said windmill mechanically.

  According to this wind power generator, the axial relative position between the rotor and the stator is automatically changed according to the wind force without depending on the electrical elements. Therefore, according to this wind power generator, it becomes easy to perform adaptive control for controlling the starting torque of the generator to be adapted to wind power with high reliability.

(4) The wind power generator according to (3), wherein the change mechanism changes the axial relative position to the first state when the wind is weak and to the second state when the wind is strong.

  According to this wind power generator, the axial length of the protruding portion is longer than that of the strong wind when the wind is weak, but the axial length of the facing portion is shorter, so the starting torque of the generator is reduced. Therefore, according to this wind power generator, it is possible to start the windmill smoothly when the wind is weak, and the generator can generate power with high efficiency when the wind is strong.

(5) Furthermore, the housing | casing which accommodates the said shaft and the said generator is included,
The stator is axially immovable relative to the housing;
The generator further includes a rotor holder that is axially movable and rotatable integrally with the shaft, and that holds the rotor coaxially,
The change mechanism is:
A support mechanism for supporting the shaft and the rotor holder so as to be axially movable and rotatable relative to the housing;
An elastic member having a load acting line parallel to the shaft;
A retainer supported by the rotor holder so as to be axially movable relative to the rotor holder, and supporting the elastic member with the rotor holder;
A stopper that is provided on the rotor holder and defines a limit for the retainer to move relative to the rotor holder by an elastic force of the elastic member in a non-operating state of the wind turbine generator;
(3) or a reaction force applying mechanism that applies a reaction force according to an axial relative movement amount of the rotor to the stator by the retainer to the elastic member via the retainer. The wind power generator according to item (4).

  In this wind power generator, the shaft, the rotor holder, and the rotor are moved in the axial direction relative to the housing by the axial force generated on the shaft by the wind. Since the length of the elastic member is changed with the axial relative movement, the axial relative movement amounts of the shaft, the rotor holder, and the rotor are changed according to the wind force.

  Further, in this wind turbine generator, in order to allow a change in the length of the elastic member, that is, a change in the elastic force, the retainer can be moved relative to the rotor holder in the axial direction, and a reaction force from the housing is generated. It is applied to the retainer via a reaction force applying mechanism.

  Further, in this wind turbine generator, a stopper that mechanically defines the limit of movement of the retainer by the elastic force of the elastic member, that is, the limit of movement of the retainer in the non-operating state of the wind turbine generator, is not applied to the housing. It is not provided for the rotor holder.

  Therefore, according to this wind power generator, it is possible to install the elastic member on the rotor holder without depending on the housing, for example, in a state where an initial load (set load, preload) is generated with high accuracy. Therefore, according to this wind turbine generator, unlike the case where the above-described stopper is provided on the housing, the relationship between the elastic force of the elastic member and the amount of relative movement of the rotor in the axial direction with respect to the stator is the manufacturing error of the housing. It is not necessary to depend on the assembly accuracy and the accuracy of the elastic force of the elastic member is improved.

  Furthermore, according to this wind turbine generator, the elastic member can be assembled to the rotor holder using the retainer and the stopper, and the assembled body can be assembled to the housing in an assembled state in which the elastic member is not detached from the rotor holder. . As a result, according to this wind power generator, the assembly work of the elastic member can be easily simplified.

(6) The wind power generator according to (5), wherein the rotor is an outer rotor positioned outside the stator, and the stator is accommodated in the rotor holder.

  According to this wind power generator, it is easier to increase the diameter of the rotor than when the rotor is an inner rotor located inside the stator. Therefore, when the generator is implemented in a manner in which a permanent magnet is installed as a field magnet on the rotor, it is easy to increase the field magnetic flux by increasing the size of the permanent magnet.

(7) The wind turbine generator according to (6), wherein the shaft is supported so as to be axially movable and rotatable while penetrating the housing.

  According to this wind power generator, it is easy to downsize the housing for the length of the shaft.

(8) The wind turbine generator according to (7), wherein the shaft penetrates the stator coaxially.

  According to this wind turbine generator, when the shaft and the stator are viewed in a direction perpendicular to the axis thereof, the shaft and the stator partially overlap, so that the shaft length dimension and the stator axial direction It becomes easy to reduce the size of the housing for the total size.

(9) The reaction force application mechanism has a single axis,
The said shaft is the wind power generator as described in the (8) term which has penetrated the reaction force provision mechanism coaxially.

  According to this wind turbine generator, when the shaft and the reaction force application mechanism are viewed in a direction perpendicular to the axis thereof, the shaft and the reaction force application mechanism partially overlap each other. It becomes easy to miniaturize the housing for the total dimension of the dimension and the axial dimension of the reaction force applying mechanism.

(10) A wind power generator that generates power using wind power,
A windmill that rotates in response to the wind,
A housing;
A shaft provided in the housing and rotating with the windmill;
A generator provided in the housing and generating electricity by being driven by the shaft, and the generator is
A rotor that rotates with the shaft;
A stator that is axially immovable relative to the housing;
A rotor holder that is axially movable and rotatable integrally with the shaft, and that holds the rotor coaxially;
When the wind turbine receives wind, it generates axial force and rotational force on the shaft,
The wind power generator further supports the rotor and the stator so as to be relatively movable in the axial direction, and an axial force generated on the shaft by the windmill with respect to the axial relative position between the rotor and the stator. Including a change mechanism that changes mechanically, and the change mechanism includes:
A support mechanism for supporting the shaft and the rotor holder so as to be axially movable and rotatable relative to the housing;
An elastic member having a load acting line parallel to the shaft;
A retainer supported by the rotor holder so as to be axially movable relative to the rotor holder, and supporting the elastic member with the rotor holder;
A stopper that is provided on the rotor holder and defines a limit for the retainer to move relative to the rotor holder by an elastic force of the elastic member in a non-operating state of the wind turbine generator;
A wind power generator comprising: a reaction force applying mechanism that applies a reaction force according to an axial relative movement amount of the rotor to the stator by the retainer to the elastic member via the retainer.

  According to this wind power generator, the relationship between the elastic force of the elastic member and the amount of axial relative movement of the rotor with respect to the stator is the same as that of the wind power generator according to item (5) above. It is not necessary to depend on the assembling accuracy, the accuracy of the elastic force of the elastic member is improved, and the work of assembling the elastic member can be easily simplified.

  In this wind turbine generator, the generator can be implemented in a mode common to the generator described in any one of the items (1) to (4), but implemented in a mode that is not common. Is possible.

  Further, in this wind turbine generator, similarly to the wind turbine generator according to the item (1), the rotor and the stator are radially separated from each other with an air gap having a shape extending in the axial direction in the same annular cross section. It is possible to design them so as to face each other, or to face each other in the radial direction with an air gap having a shape in which the diameter of the circular cross section changes in the axial direction.

(11) In the change mechanism, the relative position in the axial direction is changed so that the rotor and the stator both protrude in the axial direction from the counterpart and the counterpart in the radial direction when the wind is weak. In a first state having a facing portion, a strong wind, the axial length of the protruding portion is shorter than the first state, and the axial length of the facing portion is longer than the first state. The wind power generator according to item (10), which is changed to the state of 2.

  According to this wind power generator, as in the wind power generator according to the item (4), the axial length of the protruding portion is longer when the wind is weak than when the wind is strong. Therefore, the starting torque of the generator is reduced. Therefore, according to this wind power generator, it is possible to start the windmill smoothly when the wind is weak, and the generator can generate power with high efficiency when the wind is strong.

  Hereinafter, one of more specific embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a side sectional view showing a wind power generator 10 according to an embodiment of the present invention. FIG. 2 is an enlarged front view of a main part of the wind power generator 10.

  The wind power generation apparatus 10 is used by being mounted on a moving body such as an automobile, a train, and a ship. In the present embodiment, as shown in FIG. 1, automobiles such as passenger cars, commercial vehicles, and industrial vehicles. It is used by being detachably mounted on 12 roofs 14. The wind power generator 10 is designed to generate power using relative wind generated relatively to the automobile 12 as the automobile 12 travels. However, the wind power generator 10 can be used to generate power using natural wind when the automobile 12 is stopped.

  As shown in FIG. 1, the wind power generator 10 includes an air duct 20. The air duct 20 is formed of a synthetic resin having high heat resistance such as polycarbonate. The air duct 20 is formed with a wind tunnel 22 penetrating therethrough.

  The wind tunnel 22 extends parallel to the front-rear direction of the automobile 12 when viewed from directly above. However, when viewed from the side, the wind tunnel 22 has a front portion as shown in FIG. It is inclined with respect to the front-rear direction of the automobile 12 so as to be lower than the rear part. Hereinafter, the reason why the wind tunnel 22 is inclined and installed will be described.

  In general, the automobile 12 includes at least a front part (not shown, for example, a front windshield) and a roof 14 in view of only the part mainly related to the air flow on the upper surface thereof. The roof 14 is arranged along the air flow (wind traveling direction) in that order. The front portion has an upper surface that is inclined with respect to the horizontal plane in an upward direction from the front of the automobile 12 to the rear, whereas the roof 14 has an upper surface that is generally parallel to the horizontal plane.

  The roof 14 is connected at its upstream end to the front downstream end. Therefore, when air flows from the front to the rear in the automobile 12, the air flows parallel to the front-rear direction of the automobile 12 along the front upper surface (slope) at the upstream end of the roof 14. However, the flow of air that travels merges. This merging is convenient for the air duct 20 to efficiently take in air from the inlet, that is, with high specific gravity. However, since the combined air has an upward velocity component, when such air hits the upper surface of the wind tunnel 22 in the air duct 20, the air duct 20 tends to separate from the roof 14 (for example, the air duct 20 is downstream). A tendency to rise from the roof 14 on the side).

  The separation tendency of the air duct 20 increases as the angle formed by the direction of the air flow flowing along the upper surface of the front portion and the direction of the wind tunnel 22 increases. Therefore, in the present embodiment, in order to improve the air intake efficiency and suppress the tendency of separation of the air duct 20, the wind tunnel 22 is inclined with respect to the horizon so that the front portion of the wind tunnel 22 is lower than the rear portion. ing. The inclination angle is, for example, 3 degrees.

  As shown in FIG. 1, the wind tunnel 22 is configured to include an intake hole 24 for taking in air from the front of the automobile 12 and a guide hole 26 for guiding the air taken into the intake hole 24 downstream. Yes. The intake hole 24 is formed as a tapered hole that opens at the front portion of the air duct 20 and has an inner diameter that decreases from the front to the rear of the automobile 12. On the other hand, the guide hole 26 is formed as a cylindrical hole that extends from the downstream end of the intake hole 24 to the downstream end of the wind tunnel 22 and generally straight with the same inner diameter.

  A generator unit 30 is installed in the guide hole 26. The generator unit 30 includes a cylindrical united housing 32 that extends coaxially with the guide hole 26. The united housing 32 is configured by fitting two cylindrical stepped housings 34 and 36 each having a stepped surface at one end surface thereof so that the stepped surfaces are coaxially fitted to each other.

  As shown in FIG. 1, the generator unit 30 further includes a propeller type windmill 40. The windmill 40 is configured such that a plurality of blades 44 extend radially outwardly from a hub 42 located at the center thereof. The windmill 40 is disposed coaxially with the guide hole 26.

  As shown in FIG. 1, a generator 50 is coaxially connected to the windmill 40. In the present embodiment, the windmill 40 is an upwind type. In order to attach the generator 50 to the united housing 32, the generator unit 30 includes a bottomed cylindrical mounting housing 52 attached to the generator 50, a cylindrical support frame 54, and a plurality of rod-like connections. And a member 56. The plurality of connecting members 56 are mounted in such a manner that the plurality of connecting members 56 extend radially from the axis of the mounting housing 52 so that the mounting housing 52 is held coaxially with the mounting housing 52 in the central position in the support frame 54. The housing 52 and the support frame 54 are connected to each other.

  As shown in FIG. 1, in the combined housing 32, an annular groove 58 is formed in a portion where the two stepped housings 34 and 36 are fitted to each other. The pair of side surfaces in the groove 58 is constituted by a shoulder surface of the stepped surface of one stepped housing 34 and a tip surface of the stepped surface of the other stepped housing 36. By fitting the support frame 54 into the groove 58 formed in this way, the support frame 54 is fixed with respect to the axial position and the radial position.

  As mentioned above, although the whole structure of the wind power generator 10 according to this embodiment was demonstrated, the structure of the generator 50 is demonstrated in detail next.

  As shown in FIG. 3, the generator 50 includes a shaft 60 that extends coaxially from the windmill 40. The shaft 60 rotates together with the windmill 40, and the generator 50 generates electricity by this rotation. When the windmill 40 receives wind, a rotational force and an axial force are generated on the shaft 60. A rotational force is a force in an orientation that attempts to rotate the shaft 60 about its axis, whereas an axial force is a force in an orientation that attempts to move the shaft 60 along its axis. . In the present embodiment, the generator 50 is designed such that the shaft 60 can move in the axial direction relative to the generator 50 by the axial force generated in the shaft 60 when the windmill 40 receives wind. ing. The structure that enables the axial movement of the shaft 60 will be described in detail later.

  3 shows the generator 50 with the shaft 60 in the initial position, while FIG. 4 shows the shaft 60 with the maximum displacement position. The initial position of the shaft 60 is realized when the windmill 40 does not receive wind at all, or when it is received, it is a breeze (wind whose wind speed is equal to or lower than a set value). On the other hand, the maximum displacement position of the shaft 60 is realized when the wind turbine 40 receives a strong wind (wind speed is larger than the set value). However, the generator 50 can be designed such that the axial position of the shaft 60 changes stepwise according to the wind speed, or can be designed to change continuously according to the wind speed.

  As shown in FIG. 3, the generator 50 includes a split outer housing 62. The outer housing 62 is constituted by two divided housings 64 and 66 each having a bottomed cylindrical shape. The two split housings 64 and 66 are a front split housing 64 located on the front side (side closer to the windmill 40) of the generator 50, and a rear split housing 66 located on the rear side (side far from the windmill 40). It is comprised by. The front-side divided housing 64 and the rear-side divided housing 66 are screwed together so as to face each other at their openings, whereby the outer housing 62 is configured to have a closed space inside. Yes.

  The above-described mounting housing 52 is coaxially fixed to the outer housing 62 so as to cover the outer housing 62 from the outside. Specifically, in the present embodiment, the mounting housing 52 is fixed to the front divided housing 64 of the outer housing 62. Thus, the mounting housing 52 is fixed to the generator 50 at the axial center position of the generator unit 30 including the windmill 40 and the generator 50.

  In the outer housing 62 configured in this manner, a shaft 60 that rotates together with the wind turbine 40, a stator 70 having a coil (not shown), and a rotor 72 that is rotated relative to and coaxially with the stator 70 are disposed. Has been. The shaft 60 has an annular protrusion 74 at a certain position in the axial direction thereof, and is partitioned into a side closer to the windmill 40 and a side farther from the windmill 40 by the annular protrusion 74.

  In the present embodiment, the rotor 72 is disposed outside the stator 70. That is, the generator 50 employs an outer rotor system. Therefore, in the present embodiment, the stator 70 and the rotor 72 are opposed to each other in the radial direction on the inner peripheral surface of the rotor 72 and the outer peripheral surface of the stator 70, and an air gap is formed between them. A plurality of permanent magnets 78 formed of a metal such as neodymium are fixed to the inner peripheral surface of the main body 76 of the rotor 72 at regular intervals in the circumferential direction. In the generator 50, the permanent magnets 78 are opposed to the coils of the stator 70 with an air gap therebetween, and as a result, power is generated by relative displacement between the permanent magnets 78 and the coils. That is, this generator 50 employs a brushless system.

  As shown in FIG. 3, at the initial position of the shaft 60, the stator 70 has a protruding portion 80 that protrudes in the axial direction from the rotor 72 and a facing portion 82 that faces the rotor 72 in the radial direction. Similarly, the rotor 72 has a protruding portion 84 that protrudes from the stator 70 in the axial direction, and a facing portion 86 that faces the stator 70 in the radial direction. At the initial position of the shaft 60, the axial length of the projecting portions 80 and 84 (hereinafter referred to as “projecting length”) of both the stator 70 and the rotor 72 is maximum, while the axial direction of the facing portions 82 and 86 is the same. The length (hereinafter referred to as “opposing length”) is minimum.

  On the other hand, as shown in FIG. 4, at the maximum displacement position of the shaft 60, both the stator 70 and the rotor 72 have the protruding portions 80 and 84 having the minimum protruding length, while the opposing length is the maximum. There are certain facing portions 82 and 86. That is, at the maximum displacement position of the shaft 60, both the stator 70 and the rotor 72 have the largest facing area, and the power generation efficiency of the generator 50 is maximized.

  By the way, when the magnetic flux generated between the stator 70 and the rotor 72 is observed along the rotational axis of the rotor 72, the magnetic flux is not uniformly distributed along the rotational axis of the rotor 72. The magnetic flux is distributed three-dimensionally.

  When at least one of the stator 70 and the rotor 72 has a protruding portion that protrudes in the axial direction from the counterpart, the magnetic permeability of the protruding portion is determined by the protruding portion in the space occupied by the protruding portion. Usually, it is lower than the magnetic permeability of air that could exist if it was not present, that is, the magnetic permeability in the absence of the protrusion.

  Therefore, when there is a protrusion on at least one of the stator 70 and the rotor 72, the leakage magnetic flux between the stator 70 and the rotor 72 in a direction that is not perpendicular to the rotation axis of the rotor 72, compared to the case where there is no protrusion. Therefore, field magnetic flux tends to decrease. Therefore, when the protrusion is present, the starting torque of the generator is reduced as compared with the case where the protrusion is not present.

  Based on the knowledge described above, in this wind power generator 10, the stator 70 and the rotor 72 are relatively positioned in the axial direction so as to have the above-described protrusions.

  In this embodiment, when the wind is weak, the shaft 60 is in the initial position, and the protrusion length of both the rotor 72 and the stator 70 is maximum. As a result, when the wind is weak, the starting torque of the generator 50 is sufficiently reduced, and the windmill 40 is started smoothly.

  As shown in FIG. 3, the rotor 72 is held by a bottomed cylindrical rotor holder 90. The rotor holder 90 is disposed coaxially with the shaft 60 in the outer housing 62. The rotor holder 90 is disposed in the outer housing 62 in such a direction as to be close to the windmill 40 at the bottom 92 and away from the windmill 40 at the opening 94. A rotor 72 is coaxially fixed to the opening 94 of the rotor holder 90.

  The shaft 60 passes through the rotor holder 90 coaxially, and is fixed to the bottom 92 of the rotor holder 90 by press-fitting on the side far from the windmill 40 with respect to the annular protrusion 74. The shaft 60 and the rotor holder 90 are press-fitted so that the bottom 92 is in contact with the end face far from the windmill 40 out of both end faces of the annular protrusion 74. By this press fitting, the shaft 60 is fixed to the rotor holder 90 so as to have the necessary concentricity and squareness.

  The shaft 60 passes through the stator 70 coaxially and further passes through the outer housing 62 coaxially. The shaft 60 is supported by a pair of end portions 96 and 98 in the outer housing 62 which are opposed to each other in the axial direction so as to be rotatable and movable in the axial direction.

  Specifically, a portion of the shaft 60 closer to the windmill 40 than the annular protrusion 74 is connected to the end 96 near the windmill 40 of the pair of end portions 96 and 98 in the outer housing 62 via the metal bearing 100 as a bearing. It is supported so as to be rotatable and axially movable. On the other hand, one end of the shaft 60 far from the windmill 40 rotates to the end 98 far from the windmill 40 out of the pair of ends 96 and 98 in the outer housing 62 via the radial ball bearing 102 as a bearing. It is supported so as to be movable in the axial direction. In order to support the shaft 60 via the radial ball bearing 102 so as to be movable in the axial direction, a clearance larger than usual exists between the inner peripheral surface of the inner ring of the radial ball bearing 102 and the outer peripheral surface of the shaft 60. It has become.

  As shown in FIG. 3, a stator holder 110 having a generally cylindrical shape is inserted coaxially into the stator 70, and a shaft 60 is inserted coaxially into the stator holder 110. The stator holder 110 is configured by screwing together two end portions 112 and 114 that are both cylindrical and extend coaxially. Of these two members 112 and 114, the member far from the windmill 40 is the first member 112, and the member close to the windmill 40 is the second member 114.

  In the first member 112, a female thread 116 is formed at a proximal end portion that is an end portion close to the second member 114 of both end portions thereof, while an outward flange is formed at a distal end portion that is an opposite end portion. 118 is formed. The outer ring of the aforementioned radial ball bearing 102 is fixed to the inside of the flange 118 by fitting, and the flange 118 is fixed to the end portion 98 of the outer housing 62 with a bolt 120. The stator holder 110 passes through the stator 70 coaxially in the first member 112. The stator 70 is fixed to the stator holder 110 by the stator holder 110 so that the stator 70 cannot rotate and cannot move. As a result, the stator 70 is fixed relative to the outer housing 62.

  On the other hand, in the second member 114, a male screw 122 to be screwed to the female screw 116 is formed at a base end portion that is an end portion close to the first member 112 of both end portions thereof. A bottomed hole 124 having an inner diameter that is larger than the outer diameter of the shaft 60 is formed inside the distal end that is the opposite end. The bottomed hole 124 is opened at the distal end surface of the distal end portion, that is, the end surface facing the bottom portion 92 of the rotor holder 90. In this bottomed hole 124, two radial ball bearings 126 as bearings are mounted in series in the axial direction.

  The shaft 60 is supported by the two radial ball bearings 126 and 126 so as to be rotatable and axially movable. In order to support the shaft 60 through the radial ball bearings 126 and 126 so as to be axially movable, a clearance larger than usual is provided between the inner peripheral surface of the inner ring of the radial ball bearings 126 and 126 and the outer peripheral surface of the shaft 60. Is supposed to exist.

  The radial ball bearings 126, 126 are held in a fixed position by a stator holder 110 fixed to the outer housing 62, and as a result, the shaft 60 is connected to the shaft by the outer housing 62 via the radial ball bearings 126, 126. 60 is supported relatively firmly at a third point which is generally midway between the two supported points. Therefore, even if a bending moment is applied to the shaft 60 due to the wind turbine 40 receiving the wind obliquely, the shaft 60 is supported at three points, so that the shaft 60 is bent and bent more than when supported at two points. Is reduced. As a result, for example, it is easy to avoid interference between the rotor 72 and the stator 70, and a state in which the shaft 60 rotates stably around the same axis regardless of the bending moment of the shaft 60 is ensured. It becomes easy.

  The axial direction position of the shaft 60 changes according to the axial force of the shaft 60 reflecting the wind force. When the axial position of the shaft 60 changes, the axial position of the rotor 72 with respect to the stator 70 changes, and as a result, the protruding length and the opposing length change. If these protrusion length and opposing length change, the starting torque of the generator 50 will change. Hereinafter, the change mechanism which changes protrusion length and opposing length according to the axial force of the shaft 60 among the generators 50 is demonstrated in detail.

  A plurality of compression coil springs 130 (either tension coil springs, leaf springs, or disc springs) as elastic members are provided in the inner space of the rotor holder 90 in a posture parallel to the shaft 60 and along a concentric circle of the shaft 60. They are arranged side by side at equal intervals.

  In the inner space of the rotor holder 90, a retainer 132 that holds the compression coil spring 130 with the bottom 92 of the rotor holder 90 is disposed. The retainer 132 is slidably fitted to the inner circumferential surface of the rotor holder 90 on the outer circumferential surface thereof, and is slidably fitted to the outer circumferential surface of the shaft 60 on the inner circumferential surface thereof. . The retainer 132 can rotate integrally with the rotor holder 90, but can rotate and move axially with respect to the shaft 60.

  A cylindrical member 134 is fixed to the rotor holder 90 by screwing on the inner peripheral surface of the opening 94 thereof. On the other hand, the outer peripheral surface of the retainer 132 is formed as a stepped surface having a large diameter portion 136 and a small diameter portion 138. The outer peripheral surface of the retainer 132 is slidably fitted to the inner peripheral surface of the cylindrical member 134 at the large diameter portion 136. By fitting the large diameter portion 136 into the inner peripheral surface of the cylindrical member 134, an annular space 140 opened at one end surface is formed between the small diameter portion 138 and the inner peripheral surface of the cylindrical member 134. A needle bearing 142 as a bearing is installed in the annular space 140. A disc-shaped closing member 144 is attached to the retainer 132 to close the annular space 140, thereby preventing the needle bearing 142 from being detached from the annular space 140.

  Needle bearing 142 is originally classified as a radial bearing. However, in this embodiment, the needle bearing 142 slides in the axial direction between the retainer 132 and the cylindrical member 134 by providing a larger radial clearance between the needle bearing 142 and the cylindrical member 134 than usual. Contributes to the reduction of resistance.

  In the inner space of the rotor holder 90, the guide rods 148 are arranged in the same number as the number of the compression coil springs 130 across the bottom 92 and the retainer 132 of the rotor holder 90 and at positions where the corresponding compression coil springs 130 are coaxially penetrated. Has been. Each guide rod 148 is provided to prevent the corresponding compression coil spring 130 from buckling during compression. Each guide rod 148 passes through the closing member 144. In the present embodiment, one end of the guide rod 148 is fixed to the retainer 132, and the other end penetrates the bottom 92 of the rotor holder 90 and is slidably fitted.

  An oilless metal bushing 152 is coaxially fitted and fixed as an example of a bearing at a distal end portion of the retainer 132 facing the bottom portion 92 of the rotor holder 90. Relative axial sliding between the shaft 60 and the retainer 132 is mainly performed through the metal bush 152.

  As shown in FIG. 4, the front end surface of the metal bush 152 abuts against the bottom 92 of the rotor holder 90 and / or the stopper 154 fixed to the shaft 60 at the maximum displacement position of the shaft 60. That is, the stopper 154 is provided to define the maximum displacement position of the shaft 60 and the rotor holder 90.

  The compression coil spring 130 is mounted between the rotor holder 90 and the retainer 132 in a state having a non-zero set load, that is, in a state compressed from the natural state. It is mounted with a preload. A stopper 160 is provided on the rotor holder 90 in order to realize the set load and prevent the retainer 132 from being detached from the rotor holder 90 by the elastic force of the compression coil spring 130. As shown in FIG. 3, the retainer 132 contacts the stopper 160 at the initial position of the shaft 60.

  Specifically, the stopper 160 is provided at a position facing both ends of the retainer 132 and the end far from the windmill 40. Further, the stopper 160 is integrally formed with the aforementioned cylindrical member 134 that is manufactured separately from the main body 164 of the rotor holder 90 and attached to the main body 164.

  As shown in FIG. 3, the relay member 164 is disposed between the retainer 132 and the stator holder 110. A shaft 60 is coaxially inserted into the relay member 164. The relay member 164 is fitted to the shaft 60 so as to be slidable in the axial direction. The relay member 164 is configured such that when the shaft 60 and the rotor holder 90 are retracted (moved to the right in the figure) from the illustrated initial position, an elastic force corresponding to the retracted amount is generated in the compression coil spring 130. The axial reaction force from the outer housing 62 and the stator holder 110 is transmitted to the retainer 132.

  The retainer 132 is a rotating member that rotates together with the shaft 60 and the rotor holder 90, whereas the stator holder 110 and the outer housing 62 are non-rotating members. Therefore, in order to transmit the axial force between the retainer 132 that performs such relative rotation and the stator holder 110 by mechanical contact, the relay member 164 is, for the stator holder 110, the inner ring of the radial ball bearing 126, that is, The shaft 60 is engaged with a portion that rotates integrally with the shaft 60.

  Next, the operation of the generator 50 will be described.

  In a state where the wind force is not received by the windmill 40 or the axial force generated on the shaft 60 by the windmill 40 cannot overcome the set load (no wind or light wind), as shown in FIG. 60 is in the initial position, and the retainer 132 is in contact with the stopper 160. As a result, the protruding length is the maximum and the opposing length is the minimum. In this state, since the power generation efficiency is minimum and the magnetic flux leakage at the protrusions 80 and 84 of the stator 70 and the rotor 72 is maximum, the electromotive torque of the generator 50 is minimum.

  If the wind speed increases from this state and, as a result, the axial force generated on the shaft 60 by the windmill 40 overcomes the set load, the shaft 60 and the rotor holder 90 leave the retainer 132 and the stator holder 110 while leaving the compression coil spring. Retreats against the elastic force 130 (moves to the right in FIG. 3). The shaft 60 and the rotor holder 90 eventually reach a retreat limit where the retainer 132 abuts against the stopper 154 as shown in FIG. In this state, the protruding length is the minimum and the opposing length is the maximum. Therefore, since the facing area between the stator 70 and the rotor 72 is the maximum, and the magnetic flux leakage at the protrusions 80 and 84 of the stator 70 and the rotor 72 is the minimum, the power generation efficiency of the generator 50 is the maximum. .

  As is clear from the above description, in the present embodiment, the radial ball bearing 102, the two radial ball bearings 126, 126, the metal bearing 100, the metal bush 152, and the relay member 164 cooperate with each other in the above (5 ) Or (10) is an example of “support mechanism”, and a plurality of compression coil springs 130 is an example of “elastic member” in the same term. Further, the stopper 160 constitutes an example of the “stopper” in the same term, and the stator holder 110, the two radial ball bearings 126 and 126, and the relay member 164 cooperate with each other in the “reaction force applying mechanism” in the same term. It constitutes an example. Further, an example of the “support mechanism”, an example of the “elastic member”, an example of the “stopper”, and an example of the “reaction force imparting function” constitute one example of the “change mechanism” in the same paragraph. It is.

  By the way, if it is assumed that the above-mentioned relative wind is completely steady, the cut-in wind speed VCI is originally determined by the wind speed of the relative wind, but in a transient situation, the rotor 72 Since the rotational speed cannot respond quickly, the conventional wind power generator cannot start regular power generation by the generator at an early stage. On the other hand, according to this embodiment, since the windmill 40 is started early, that is, smoothly, the power generation by the generator 50 can be started early.

  Furthermore, in this embodiment, the stopper 160 that mechanically defines the limit of movement of the retainer 132 by the elastic force of the compression coil spring 130, that is, the limit of movement of the retainer 132 when the wind turbine generator 10 is in an inoperative state. It is provided not for the housing 62 but for the rotor holder 90.

  Therefore, according to the present embodiment, it is possible to install the compression coil spring 130 on the rotor holder 90 without depending on the outer housing 62 in a state where the set load is generated with high accuracy. Therefore, according to the present embodiment, unlike the case where the stopper 160 is provided for the outer housing 62, the relationship between the elastic force of the compression coil spring 130 and the amount of relative movement of the rotor 72 in the axial direction with respect to the stator 70 is The manufacturing error of the outer housing 62 and the assembling accuracy are not required, and the accuracy of the elastic force of the compression coil spring 130 is improved.

  Furthermore, according to the present embodiment, the compression coil spring 130 is assembled to the rotor holder 90 using the retainer 132 and the cylindrical member 134 on which the stopper 160 is formed, and the compression coil spring 130 is in an assembled state in which the compression coil spring 130 is not detached from the rotor holder 90. These assembly bodies can be assembled to the outer housing 62. As a result, according to this embodiment, the assembly work of the compression coil spring 130 can be easily simplified.

  Although one embodiment of the present invention has been described in detail with reference to the drawings, this is an exemplification and is based on the knowledge of those skilled in the art including the aspects described in the section of [Disclosure of the Invention]. The present invention can be implemented in other forms with various modifications and improvements.

It is a side view which shows the wind power generator 10 according to one Embodiment of this invention. It is a front view which shows the generator unit 30 in the wind power generator 10 shown in FIG. FIG. 2 is a partial side cross-sectional view showing the generator unit 30 in FIG. 1 with a shaft 60 in an initial position. It is side surface sectional drawing which shows the generator 50 in FIG. 1 in the state in which the shaft 60 exists in a maximum displacement position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wind power generator 40 Windmill 50 Generator 60 Shaft 62 Outer housing 70 Stator 72 Rotor 80,84 Protruding part 82,86 Opposite part 90 Rotor holder 130 Compression coil spring 132 Retainer 160 Stopper 164 Relay member

Claims (11)

A wind power generator that generates power using wind power,
A windmill that rotates in response to the wind,
A shaft that rotates with the windmill,
A generator for generating electricity by being driven by the shaft, and the generator
A rotor that rotates together with the shaft and a stator, and at least one of the rotor and the stator has a protruding portion that protrudes in the axial direction from the counterpart, and a facing portion that faces the counterpart in the radial direction. Wind power generator.   Further, the rotor and the stator are supported so as to be relatively movable in the axial direction, and the relative position in the axial direction between the rotor and the stator is in a first state where both the projecting portion and the facing portion exist. And a change mechanism that selectively changes the axial length of the protruding portion to a second state shorter than the first state and the axial length of the facing portion is longer than the first state. The wind power generator according to claim 1 containing. When the wind turbine receives wind, it generates axial force and rotational force on the shaft,
The wind power generator according to claim 2, wherein the changing mechanism changes the axial relative position by mechanically using an axial force generated on the shaft by the windmill.   The wind power generator according to claim 3, wherein the change mechanism changes the axial relative position to the first state when the wind is weak and to the second state when the wind is strong. And a housing that houses the shaft and the generator,
The stator is axially immovable relative to the housing;
The generator further includes a rotor holder that is axially movable and rotatable integrally with the shaft, and that holds the rotor coaxially,
The change mechanism is:
A support mechanism for supporting the shaft and the rotor holder so as to be axially movable and rotatable relative to the housing;
An elastic member having a load acting line parallel to the shaft;
A retainer supported by the rotor holder so as to be axially movable relative to the rotor holder, and supporting the elastic member with the rotor holder;
A stopper that is provided on the rotor holder and defines a limit for the retainer to move relative to the rotor holder by an elastic force of the elastic member in a non-operating state of the wind turbine generator;
A reaction force applying mechanism that applies a reaction force according to an axial relative movement amount of the rotor to the stator by the retainer to the elastic member via the retainer. 5. The wind power generator according to 4.   The wind turbine generator according to claim 5, wherein the rotor is an outer rotor positioned outside the stator, and the stator is accommodated in the rotor holder.   The wind turbine generator according to claim 6, wherein the shaft is supported so as to be axially movable and rotatable while penetrating the housing.   The wind turbine generator according to claim 7, wherein the shaft passes through the stator coaxially. The reaction force application mechanism has a uniaxial line,
The wind power generator according to claim 8, wherein the shaft penetrates the reaction force applying mechanism coaxially. A wind power generator that generates power using wind power,
A windmill that rotates in response to the wind,
A housing;
A shaft provided in the housing and rotating with the windmill;
A generator provided in the housing and generating electricity by being driven by the shaft, and the generator is
A rotor that rotates with the shaft;
A stator that is axially immovable relative to the housing;
A rotor holder that is axially movable and rotatable integrally with the shaft, and that holds the rotor coaxially;
When the wind turbine receives wind, it generates axial force and rotational force on the shaft,
The wind power generator further supports the rotor and the stator so as to be relatively movable in the axial direction, and an axial force generated on the shaft by the windmill with respect to the axial relative position between the rotor and the stator. Including a change mechanism that changes mechanically, and the change mechanism includes:
A support mechanism for supporting the shaft and the rotor holder so as to be axially movable and rotatable relative to the housing;
An elastic member having a load acting line parallel to the shaft;
A retainer supported by the rotor holder so as to be axially movable relative to the rotor holder, and supporting the elastic member with the rotor holder;
A stopper that is provided on the rotor holder and defines a limit for the retainer to move relative to the rotor holder by an elastic force of the elastic member in a non-operating state of the wind turbine generator;
A wind power generator comprising: a reaction force applying mechanism that applies a reaction force according to an axial relative movement amount of the rotor to the stator by the retainer to the elastic member via the retainer.   The change mechanism includes a projecting portion in which the rotor and the stator both project in the axial direction from the counterpart and a facing portion in which the counterpart faces the counterpart in the radial direction when the wind is weak. In a first state having a strong wind, the axial length of the projecting portion is shorter than the first state, and the axial length of the facing portion is a second state longer than the first state. The wind power generator according to claim 10 which is changed to

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