Wind power generator

Abstract

To easily perform assembly work and to easily adjust preload applied to a rolling element of a bearing device for supporting a plurality of blades to a housing.SOLUTION: A bearing device 5 comprises: an outer ring 17 having double-row outer ring raceways 16a, 16b on its inner peripheral surface and supported with respect to the housing 2; an inner member 20 including two inner ring elements 19a, 19b having single-row inner ring raceways 18a, 18b on its outer peripheral surface, respectively, and supported with respect to a plurality of blades 3 and a main shaft 6 or a rotating member connected to the main shaft 6 so as to be able to transmit torque; a plurality of rolling elements 21a, 21b arranged in double rows between the double-row outer ring raceways 16a, 16b and respective inner ring raceways 18a, 18b of the two inner ring elements 19a, 19b, and applied with preload.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a wind turbine generator. [Background technology]

[0002] In a wind turbine, a rotating shaft to which multiple blades are fixed is rotated by the force of wind, and the rotation of the rotating shaft is accelerated by a gearbox and transmitted to a generator, which generates electricity. Known wind turbines include horizontal-axis types in which the rotating shaft is arranged parallel to the ground, and vertical-axis types in which the rotating shaft is arranged perpendicular to the ground.

[0003] Japanese Patent Application Laid-Open Publication No. 2013-228057 describes a gyromill-type (straight blade) wind turbine, which is a type of vertical-axis wind turbine. The gyromill-type wind turbine is equipped with a plurality of blades, each of which has a substantially rectangular plate shape and extends vertically. The blades are arranged at equal intervals in the circumferential direction around a rotating shaft and are supported on the rotating shaft via arms.

[0004] In the wind turbine generator described in JP 2013-228057 A, the rotating shaft is rotatably supported inside a housing (casing) via a double-row angular bearing and one radial bearing. The double-row angular bearing is configured by arranging multiple balls freely rollably between outer ring raceways (ball rolling grooves) formed on the inner peripheral surfaces of a pair of outer rings fitted and fixed inside the housing, and a pair of inner ring raceways (ball rolling grooves) formed on the outer peripheral surface of the rotating shaft. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-228057 Summary of the Invention [Problem to be solved by the invention]

[0006] Generally, a wind power generation device is assembled at the installation site. In the wind power generation device described in Japanese Patent Application Laid-Open No. 2013-228057, a pair of inner ring races of a double-row angular bearing are directly formed on the outer peripheral surface of a rotating shaft supported by a housing by the double-row angular bearing. Therefore, at the installation site of the wind power generation device, it is necessary to assemble the double-row angular bearing while preventing foreign matter from entering the inside, and the assembly work becomes troublesome and the cost inevitably increases. In addition, it becomes difficult to adjust the preload applied to a plurality of balls to an appropriate magnitude. As a result, when the preload becomes smaller than the appropriate magnitude, the moment rigidity becomes insufficient and vibration of the rotating shaft is likely to occur, or when the preload becomes larger than the appropriate magnitude, the rotational resistance of the rotating shaft may increase unnecessarily.

[0007] An object of the present disclosure is to realize a wind power generation device that can easily perform assembly work and can easily adjust the preload applied to rolling elements of a bearing device that supports a plurality of blades with respect to a housing.

Means for Solving the Problems

[0008] The wind power generation device according to the first aspect of the present disclosure includes a housing, a plurality of blades, a generator having a main shaft, a bearing device that rotatably supports the plurality of blades and a rotating member that is torque-transmittably connected to the main shaft or the main shaft with respect to the housing, and includes.

[0009] In particular, in the wind power generation device according to the first aspect of the present disclosure, the bearing device includes an outer ring having a double-row outer ring race on an inner peripheral surface and supported and fixed to the housing, two inner ring elements each having a single-row inner ring race on an outer peripheral surface, and an inner member supported and fixed to the plurality of blades and the main shaft or the rotating member, A plurality of rolling elements that are rotatably disposed between the outer ring raceway of the double row and the single row inner ring raceways of the two inner ring elements and are preloaded, and are provided.

[0010] In the wind power generation device according to the second aspect of the present disclosure, in the wind power generation device according to the first aspect of the present disclosure, the plurality of blades are supported and fixed to the main shaft or the rotating member, and the two inner ring elements are externally fitted and fixed to the main shaft or the rotating member.

[0011] The wind power generation device according to the third aspect of the present disclosure further includes a rotor hub to which the plurality of blades are supported and fixed in the wind power generation device according to the first aspect of the present disclosure, and the main shaft or the rotating member has an engaging shaft portion. Further, in the wind power generation device according to the third aspect of the present disclosure, the inner member includes an inner ring fitting surface portion provided on the outer peripheral surface and into which the two inner ring elements are externally fitted, a rotating flange that protrudes radially outward and to which the rotor hub is coupled and fixed so as to be torque-transmissible, and a hub spindle having an engaging hole to which the engaging shaft portion is torque-transmissibly engaged.

[0012] The wind power generation device according to the fourth aspect of the present disclosure further includes a rotor hub to which the plurality of blades are supported and fixed in the wind power generation device according to the first aspect of the present disclosure, and the main shaft or the rotating member has an engaging shaft portion. In the wind power generation device according to the fourth aspect of the present disclosure, one of the two inner ring elements includes the single row inner ring raceway, an inner ring fitting surface portion provided on the outer peripheral surface and into which the other of the two inner ring elements is externally fitted, a rotating flange that protrudes radially outward and to which the rotor hub is coupled and fixed so as to be torque-transmissible, and an engaging hole to which the engaging shaft portion is torque-transmissibly engaged.

[0013] In the wind power generation device according to the fifth aspect of the present disclosure, in the wind power generation device according to any one of the first to fourth aspects of the present disclosure, the outer ring is snugly fitted into the housing without rattling.

[0014] In the wind power generation device according to the sixth aspect of the present disclosure, in the wind power generation device according to any one of the first to fourth aspects of the present disclosure, the outer ring has a fixed flange protruding radially outward, and is supported and fixed to the housing by an outer ring fixing member disposed so as to span between the fixed flange and the housing.

[0015] The wind power generation device according to the seventh aspect of the present disclosure is the wind power generation device according to any one of the first to sixth aspects of the present disclosure, and further includes a rotation speed detection device having a detected portion in which magnetic characteristics change alternately and at equal intervals in the circumferential direction, an encoder supported and fixed to the inner member, and a sensor having a detection portion facing the detected portion and supported and fixed to the housing.

[0016] The wind power generation device according to the eighth aspect of the present disclosure can further include a speed changer having an input member and an output member connected to the main shaft so as to be torque-transmittable. In this case, the rotating member is constituted by the input member.

[0017] The wind power generation device according to the ninth aspect of the present disclosure is the wind power generation device according to any one of the first to seventh aspects of the present disclosure, and further includes a constant velocity joint including a joint inner ring having inner diameter side engagement grooves at a plurality of circumferential positions on the outer peripheral surface, a joint outer ring having outer diameter side engagement grooves at a plurality of circumferential positions on the inner peripheral surface, and a plurality of balls disposed so as to be rollable along the inner diameter side engagement grooves and the outer diameter side engagement grooves between the inner diameter side engagement grooves and the outer diameter side engagement grooves. In this case, the joint inner ring is torque-transmittably connected to the main shaft or an input member of a speed changer that torque-transmittably connects an output member thereof to the main shaft, and the rotating member is constituted by the joint outer ring.

[0018] In the wind power generation device according to any one of the first to ninth aspects of the present disclosure, the rolling element can be constituted by a ball or a cylindrical roller.

Advantages of the Invention

[0019] According to the wind power generation device of one aspect of the present disclosure, assembly work can be easily performed, and adjustment of the preload applied to the rolling elements of the bearing device that supports a plurality of blades with respect to the housing can be easily performed.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Embodiments for Carrying Out the Invention

[0021] [First Example] The wind power generation device according to the first example of the embodiment of the present disclosure will be described with reference to FIG. 1.

[0022] This example is an example in which the wind power generation device of one aspect of the present disclosure is applied to a gyro mill type wind power generation device, which is a type of vertical axis wind power generation device.

[0023] However, the wind power generation device of one aspect of the present disclosure is not limited to the gyro mill type wind power generation device, and can also be applied to vertical axis wind power generation devices such as the Darrieus type, Savonius type, and paddle type, or horizontal axis wind power generation devices such as the propeller type, multi-wing type, sail wing type, and Dutch type.

[0024] The wind power generation device 1 of this example includes a housing 2, a plurality of blades 3, a generator 4, and a bearing device 5.

[0025] In the description of this example, unless otherwise specified, the axial direction, the radial direction, and the circumferential direction refer to the axial direction, the radial direction, and the circumferential direction of the bearing device 5. Also, one side in the axial direction is the upper side in FIG. 1, and the other side in the axial direction is the lower side in FIG. 1.

[0026] Note that since the wind power generation device 1 of this example is a vertical-axis wind power generation device, the central axis of the bearing device 5 that rotatably supports the plurality of blades 3 with respect to the housing 2 is arranged in the vertical direction (up and down direction). That is, the axial direction of the bearing device 5 coincides with the vertical direction.

[0027] When the wind power generation device according to one aspect of the present disclosure is applied to a horizontal-axis wind power generation device, the central axis of the bearing device is arranged in the horizontal direction. In this case, the axial direction of the bearing device coincides with the horizontal direction.

[0028] The housing 2 has a cylindrical shape. The housing 2 has an inner peripheral surface in the shape of a stepped cylindrical surface. That is, the inner peripheral surface of the housing 2 connects a large-diameter cylindrical surface portion 7 on one side in the axial direction and a small-diameter cylindrical surface portion 8 on the other side in the axial direction by an outer-diameter side step surface 9 facing one side in the axial direction. The outer-diameter side step surface 9 is constituted by a flat surface orthogonal to the central axis of the housing 2.

[0029] Each of the plurality of blades 3 is configured in a substantially rectangular plate shape or a strip shape that extends in the vertical direction.

[0030] The plurality of blades 3 are supported and fixed to the main shaft 6 of the generator 4 or a rotating member that is torque-transmissibly connected to the main shaft 6. In this example, the plurality of blades 3 are supported and fixed to the main shaft 6. Specifically, the plurality of blades 3 are arranged at a plurality of circumferentially equally spaced positions around a portion of the main shaft 6 that protrudes axially on one side beyond the end portion on one axial side of the housing 2, and are supported and fixed to the main shaft 6 via the arms 10. More specifically, by spanning the arms 10 between two axial positions on the side surfaces of both sides in the plate thickness direction of the plurality of blades 3 that face the inner side in the radial direction and two axial positions on the outer peripheral surface of the end portion on one axial side of the main shaft 6, each blade 3 is supported and fixed to the main shaft 6.

[0031] In this example, the plurality of blades 3 are composed of four blades. However, the number of blades can also be three or less, or five or more.

[0032] The generator 4 has a main shaft 6 and converts the rotational energy of the main shaft 6 into electric power. For this purpose, the generator 4 further has a rotor 11 and a stator 12.

[0033] The main shaft 6 is rotatably supported inside the housing 2 by a bearing device 5.

[0034] In this example, the main shaft 6 has a stepped cylindrical shape. Specifically, the main shaft 6 includes a small-diameter portion 13 arranged at the end portion on one axial side and a large-diameter portion 14 arranged adjacent to the other axial side of the small-diameter portion 13 and having an outer diameter larger than that of the small-diameter portion 13. The outer peripheral surface of the small-diameter portion 13 and the outer peripheral surface of the large-diameter portion 14 are connected by an inner-diameter side stepped surface 15 facing one axial side. The inner-diameter side stepped surface 15 is composed of a flat surface orthogonal to the central axis of the main shaft 6.

[0035] The rotor 11 is externally fitted and fixed to the large-diameter portion 14 of the main shaft 6 so as to rotate integrally with the main shaft 6.

[0036] The stator 12 is arranged coaxially with and rotatable relative to the rotor 11 around the rotor 11, and is fixedly fitted inside the small-diameter cylindrical surface portion 8 of the housing 2.

[0037] In addition, the generator 4 can have a variable resistor (not shown). The generator 4 can adjust the rotational speed (number of revolutions) of the main shaft 6 by adjusting the resistance value of the variable resistor. Specifically, for example, by adjusting the resistance value of the variable resistor, the rotational speed of the main shaft 6 can be adjusted to a value with high power generation efficiency. However, when implementing the wind power generation device according to an aspect of the present disclosure, the variable resistor can also be omitted.

[0038] The bearing device 5 rotatably supports the plurality of blades 3 and the main shaft 6 or the rotating member with respect to the housing 2.

[0039] The bearing device 5 has double-row outer raceways 16a, 16b on the inner peripheral surface, includes an outer ring 17 supported by the housing 2, and two inner ring elements 19a, 19b each having a single-row inner raceway 18a, 18b on the outer peripheral surface, and includes a plurality of blades 3 and an inner member 20 supported by the main shaft 6 or the rotating member, and a plurality of rolling elements 21a, 21b arranged in double rows and preloaded between the double-row outer raceways 16a, 16b and the inner raceways 18a, 18b of the two inner ring elements 19a, 19b respectively.

[0040] In this example, the bearing device 5 rotatably supports the main shaft 6 to which the plurality of blades 3 are supported and fixed with respect to the housing 2.

[0041] In this example, the main shaft 6 is supported by the bearing device 5 only with respect to the housing 2. However, when implementing the wind power generation device according to an aspect of the present disclosure, in addition to the bearing device 5, one or more other bearings can be used to support the main shaft with respect to the housing. In this case, as each bearing, it is preferable to use a rolling bearing including an inner ring separate from the main shaft, an outer ring separate from the housing, and a plurality of rolling elements arranged between the inner ring and the outer ring.

[0042] In this example, balls are used as the plurality of rolling elements 21a and 21b. However, when implementing the wind power generation device according to one aspect of the present disclosure, tapered rollers can also be used as the plurality of rolling elements constituting the bearing device.

[0043] Also, in this example, the rolling elements 21a and 21b arranged in a double row are provided with a preload and a contact angle of the back-to-back type (DB type). However, when implementing the wind power generation device according to one aspect of the present disclosure, a contact angle of the face-to-face type (DF type) or the tandem type (DT type) can also be provided to the rolling elements arranged in a double row.

[0044] The outer ring 17 is formed into a substantially cylindrical shape by a hard metal such as bearing steel or carburized steel. The double-row outer ring raceways 16a and 16b have an arcuate bus shape and are formed on the inner peripheral surface of the outer ring 17. The outer peripheral surface of the outer ring 17 is constituted by a cylindrical surface whose outer diameter does not change in the axial direction except for the end portions on both axial sides.

[0045] The outer ring 17 is snugly fitted into the large-diameter cylindrical surface portion 7 of the housing 2 without play.

[0046] Also, the outer ring 17 abuts the end surface on the other axial side against the outer diameter side step surface 9, and the end surface on one axial side abuts or is opposed in proximity to an outer diameter side retaining ring 22 locked to the end portion on one axial side of the large-diameter cylindrical surface portion 7. In other words, the outer ring 17 is axially clamped between the outer diameter side step surface 9 and the outer diameter side retaining ring 22. Thereby, the axial movement of the outer ring 17 with respect to the housing 2 is prevented.

[0047] The inner member 20 is arranged coaxially with the outer ring 17 on the radially inner side of the outer ring 17. In this example, the inner member 20 is composed of only two inner ring elements 19a and 19b.

[0048] The two inner ring elements 19a and 19b are externally fitted onto the main shaft 6. In this example, the two inner ring elements 19a and 19b have shapes that are symmetric with respect to each other in the axial direction. Each of the inner ring elements 19a and 19b is formed in a substantially cylindrical shape from a hard metal such as bearing steel or carburized steel.

[0049] Of the two inner ring elements 19a and 19b, the inner ring raceway 18a formed on the outer peripheral surface of the inner ring element 19a on one side in the axial direction has an arcuate generatrix shape in which the outer diameter increases as it goes toward one side in the axial direction. The inner peripheral surface of the inner ring element 19a on one side in the axial direction is constituted by a cylindrical surface whose inner diameter does not change in the axial direction except for the end portions on both sides in the axial direction.

[0050] Of the two inner ring elements 19a and 19b, the inner ring raceway 18b formed on the outer peripheral surface of the inner ring element 19b on the other side in the axial direction has an arcuate generatrix shape in which the outer diameter increases as it goes toward the other side in the axial direction. The inner peripheral surface of the inner ring element 19b on the other side in the axial direction is constituted by a cylindrical surface whose inner diameter does not change in the axial direction except for the end portions on both sides in the axial direction.

[0051] The two inner ring elements 19a and 19b are externally fitted onto the small-diameter portion 13 of the main shaft 6 in a state where the end faces on the small-diameter side of each other are abutted or in a state where they face each other with an axial gap therebetween, without rattling.

[0052] Further, the inner ring element 19b on the other side in the axial direction abuts the end face on the other side in the axial direction against the inner diameter side stepped surface 15, and the inner ring element 19a on one side in the axial direction abuts the side surface on one side in the axial direction against the inner diameter side retaining ring 24 locked in the locking groove 23 formed on the outer peripheral surface of the small-diameter portion 13. In other words, the inner member 20 composed of the two inner ring elements 19a and 19b is axially clamped between the inner diameter side stepped surface 15 and the inner diameter side retaining ring 24. Thereby, the axial movement of the inner member 20 with respect to the main shaft 6 is blocked, and a preload is applied to the rolling elements 21a and 21b arranged in a double row. That is, in the wind power generation device 1 of this example, by changing the axial thickness of the inner diameter side retaining ring 24 locked in the locking groove 23, the preload applied to the rolling elements 21a and 21b arranged in a double row can be adjusted.

[0053] A plurality of rolling elements 21a, 21b are arranged in two rows, with a plurality of them in each row, and are rotatably held by cages 25a, 25b between the double-row outer raceways 16a, 16b and the inner raceways 18a, 18b of the two inner ring elements 19a, 19b respectively.

[0054] The bearing device 5 of this example is provided with two seal devices 27a, 27b that exist between the inner peripheral surface of the outer ring 17 and the outer peripheral surface of the inner member 20 and close the openings on both axial sides of the bearing internal space 26 where the rolling elements 21a, 21b are arranged. Thereby, leakage of the grease enclosed in the bearing internal space 26 to the outside and intrusion of foreign matter from the outside into the bearing internal space 26 are prevented.

[0055] Each of the seal devices 27a, 27b is not limited to this, but for example, it can be constituted by a combination seal ring including a slinger externally fitted and fixed to the axial end of the inner member 20, at least one seal in sliding contact with the slinger, and a seal ring internally fitted and fixed to the axial end of the outer ring 17.

[0056] Note that the wind power generation device 1 of this example can be provided with a braking device for braking the rotation of the main shaft 6 between the housing 2 and the main shaft 6. During strong winds such as typhoons, by preventing the rotation of the main shaft 6 with the braking device, a failure of the wind power generation device 1 caused by the main shaft 6 rotating beyond the allowable maximum rotational speed is prevented. However, when implementing the wind power generation device according to one aspect of the present disclosure, the braking device can also be omitted.

[0057] In the wind power generation device 1 of this example, as the wind blows against the plurality of blades 3, when the main shaft 6 to which the plurality of blades 3 are supported and fixed rotates, power generation is performed by the generator 4.

[0058] In this example, a bearing device 5 for rotatably supporting a main shaft 6 with respect to a housing 2 includes an outer ring 17 having a double-row of outer ring raceways 16a and 16b on its inner peripheral surface, and an inner member 20 including two inner ring elements 19a and 19b each having a single-row of inner ring raceways 18a and 18b on its outer peripheral surface. Therefore, before incorporating the bearing device 5 between the housing 2 and the main shaft 6, it can be assembled at a factory and unitized. For this reason, according to the wind power generation device 1 of this example, unlike the wind power generation device described in Japanese Patent Application Laid-Open No. 2013-228057, there is no need to assemble a double-row angular bearing at an installation site while preventing foreign matter from entering the interior, and the assembly work can be facilitated.

[0059] Also, in this example, the inner member 20 of the bearing device 5 is configured to include two inner ring elements 19a and 19b each having a single-row of inner ring raceways 18a and 18b on its outer peripheral surface. Therefore, by adjusting the force with which the two inner ring elements 19a and 19b press against each other, the preload applied to the rolling elements 21a and 21b arranged in a double-row can be adjusted. Specifically, in this example, by changing the axial thickness of the inner diameter side retaining ring 24 that engages with the locking groove 23, the preload applied to the rolling elements 21a and 21b arranged in a double-row can be adjusted. For this reason, it is possible to appropriately ensure the moment rigidity of the bearing device 5, prevent the main shaft 6 from vibrating, and prevent the rotational resistance of the main shaft 6 from increasing unnecessarily.

[0060] [Second Example] A second example of the embodiment of the present disclosure will be described with reference to FIG. 2.

[0061] The wind power generation device 1a of this example includes a rotor hub 28 to which a plurality of blades 3 are supported and fixed. The rotor hub 28 is configured separately from the main shaft 6a of the generator 4a and is arranged coaxially with the main shaft 6a.

[0062] The rotor hub 28 includes a substantially disk-shaped base portion 29 and a columnar shaft portion 30 that protrudes axially on one side from the central portion of the side surface on one axial side of the base portion 29.

[0063] The base 29 is provided with a fitting recess 31 having a circular opening shape at the center of the side surface on the other axial side.

[0064] The base 29 has a plurality of thick portions 32 and a plurality of thin portions 33 that are alternately arranged in the circumferential direction in the radially outer portion. The side surface on the other axial side of the thick portion 32 and the side surface on the other axial side of the thin portion 33 are on the same plane perpendicular to the central axis of the rotor hub 28. Therefore, the side surface on one axial side of the thin portion 33 is located on the other axial side than the side surface on one axial side of the thick portion 32.

[0065] The base 29 has a plurality of through holes 34 that penetrate the plurality of thin portions 33 in the axial direction.

[0066] The plurality of blades 3 are arranged at a plurality of equally spaced positions in the circumferential direction around the shaft portion 30 and are supported and fixed to the shaft portion 30 via the arms 10. Specifically, by stretching the arms 10 between two axial positions of the shaft portion 30 and two axial positions of the side surfaces facing the radially inner side among the side surfaces on both sides in the plate thickness direction of the plurality of blades 3, each blade 3 is supported and fixed to the rotor hub 28.

[0067] The main shaft 6a of the generator 4a has a stepped cylindrical shape. Specifically, the main shaft 6a includes an engagement shaft portion 35 and a large-diameter portion 14 that is arranged adjacent to the other axial side of the engagement shaft portion 35 and has an outer diameter larger than the outer diameter of the engagement shaft portion 35. The outer peripheral surface of the engagement shaft portion 35 and the outer peripheral surface of the large-diameter portion 14 are connected by an inner-diameter side stepped surface 15 facing one axial side.

[0068] The engagement shaft portion 35 has a non-circular cross-sectional shape.

[0069] Note that the axial length of the engagement shaft portion 35 is shorter than the axial length of the small-diameter portion 13 of the main shaft 6 in the first example.

[0070] In this example, the main shaft 6a further includes a threaded shaft portion 36 at the tip portion (the end portion on one axial side) adjacent to the one axial side of the engagement shaft portion 35.

[0071] In this example, the inner member 20a that constitutes the bearing device 5a includes two inner ring elements 19a and 19b each having a single row of inner ring raceways 18a and 18b on the outer peripheral surface, and a hub spindle 37.

[0072] The two inner ring elements 19a and 19b have basically the same structure as the two inner ring elements 19a and 19b that constitute the inner member 20 of the first example.

[0073] The hub spindle 37 includes an inner ring fitting surface portion 38 provided on the outer peripheral surface and into which the two inner ring elements 19a and 19b are externally fitted, a rotation flange 39 that protrudes radially outward and to which the rotor hub 28 is coupled and fixed so as to be torque-transmittable, and an engagement hole 40 into which the engagement shaft portion 35 is engaged so as to be torque-transmittable.

[0074] The inner ring fitting surface portion 38 is provided on the outer peripheral surface of the other axial side portion of the hub spindle 37 and is constituted by a cylindrical surface whose outer diameter does not change in the axial direction except for the end portion on one axial side. The two inner ring elements 19a and 19b are externally fitted to the inner ring fitting surface portion 38 without play in a state where the end surfaces on the smaller diameter side of each other are abutted. In this example, the two inner ring elements 19a and 19b are press-fitted (including light press-fitting) into the inner ring fitting surface portion 38.

[0075] The rotation flange 39 is provided on a portion of the hub spindle 37 that protrudes axially on one side with respect to the outer ring 17. The rotation flange 39 has mounting holes 41 penetrating axially at a plurality of circumferential positions in the radial intermediate portion.

[0076] The engagement hole 40 is provided so as to axially penetrate the center portion of the hub spindle 37. The engagement hole 40 has a non-circular opening shape.

[0077] The main shaft 6a and the hub spindle 37 are combined so as to be able to transmit torque by non-circularly engaging the engaging shaft portion 35 and the engaging hole 40. Specifically, in this example, the male spline portion provided on the outer peripheral surface of the engaging shaft portion 35 and the female spline portion provided on the inner peripheral surface of the engaging hole 40 are spline-engaged, whereby the rotor hub 28 and the hub spindle 37 are coupled and fixed so as to be able to transmit torque. However, the engagement structure between the engaging shaft portion and the engaging hole is not limited to spline engagement, and structures such as serration engagement and key engagement can be adopted.

[0078] The main shaft 6a and the inner member 20a are coupled and fixed by non-circularly engaging the engaging shaft portion 35 and the engaging hole 40 and screwing a nut 42 onto the screw shaft portion 36.

[0079] In a state where the main shaft 6a and the inner member 20a are coupled and fixed, the inner ring element 19b on the other axial side abuts the end surface on the other axial side against the inner diameter side step surface 15, and the inner ring element 19a on one axial side abuts the side surface on one axial side against the side surface on the other axial side of the rotary flange 39. In other words, the two inner ring elements 19a and 19b are axially sandwiched between the inner diameter side step surface 15 and the side surface on the other axial side of the rotary flange 39. Thereby, the axial movement of the two inner ring elements 19a and 19b is prevented, and preload is applied to the rolling elements 21a and 21b arranged in a double row.

[0080] In the wind power generation device 1a of this example, by adjusting the force for axially sandwiching the two inner ring elements 19a and 19b between the inner diameter side step surface 15 and the side surface on the other axial side of the rotary flange 39, the preload applied to the rolling elements 21a and 21b arranged in a double row can be adjusted. Specifically, by adjusting the screwing amount of the nut 42 with respect to the screw shaft portion 36, the preload applied to the rolling elements 21a and 21b arranged in a double row can be adjusted.

[0081] In addition, when implementing the wind power generation device according to one aspect of the present disclosure, as the structure of the inner member of the bearing device, at the end portion on the other axial side of the hub spindle that protrudes further on the other axial side than the inner ring element on the other axial side in the axial direction, a caulking portion bent radially outward presses the end face on the other axial side of the inner ring element on the other axial side in the axial direction, thereby adopting a structure for coupling and fixing the hub spindle and the two inner ring elements. In this case, by adjusting the magnitude of the force with which the caulking portion presses the end face on the other axial side of the inner ring element on the other axial side in the axial direction, the preload applied to the rolling elements arranged in a double row can be adjusted.

[0082] In this example, the hub spindle 37 further includes a cylindrical pilot portion 43 at the end portion on one axial side.

[0083] The rotor hub 28 and the hub spindle 37 are coupled and fixed by fitting the pilot portion 43 into the fitting recess 31 without play and passing a coupling member 44 through the through hole 34 and the mounting hole 41.

[0084] Specifically, in this example, the coupling member 44 constituted by bolts is inserted through the through hole 34 and screwed into the mounting hole 41 constituted by threaded holes, thereby coupling and fixing the rotor hub 28 and the hub spindle 37. Note that the structure for coupling and fixing the rotor hub and the hub spindle is not limited to the structure of this example, and various structures can be adopted. For example, a coupling member constituted by bolts can be inserted through the through hole and the mounting hole, and a nut can be screwed onto the tip of the coupling member to couple and fix the rotor hub and the hub spindle. Alternatively, a coupling member constituted by studs can be press-fitted into the mounting hole from the other axial side, inserted through the through hole, and then a nut can be screwed onto the tip of the coupling member to couple and fix the rotor hub and the hub spindle.

[0085] In this example, as the wind blows against the plurality of blades 3, the rotor hub 28 to which the plurality of blades 3 are supported and fixed rotates, and the inner member 20a to which the rotor hub 28 is coupled and fixed rotates. With the rotation of the inner member 20a, power generation is performed by the rotation of the main shaft 6a coupled and fixed to the inner member 20a.

[0086] In this example, the bearing device 5a for rotatably supporting the main shaft 6a and the rotor hub 28 to which the plurality of blades 3 are supported and fixed with respect to the housing 2 includes an outer ring 17 having a double row of outer raceways 16a, 16b on the inner peripheral surface, and an inner member 20a including two inner ring elements 19a, 19b each having a single row of inner raceways 18a, 18b on the outer peripheral surface. Therefore, similar to the bearing device 5 of the first example, the bearing device 5a can be assembled and unitized at the factory before being incorporated between the housing 2, the main shaft 6a, and the rotor hub 28, facilitating the assembly work of the wind power generation device 1a.

[0087] Also, in this example, the inner member 20a of the bearing device 5a is configured to include two inner ring elements 19a, 19b each having a single row of inner raceways 18a, 18b on the outer peripheral surface. Therefore, by adjusting the force with which the two inner ring elements 19a, 19b press against each other, the preload applied to the rolling elements 21a, 21b arranged in a double row can be adjusted. Specifically, in this example, by adjusting the screwing amount of the nut 42 with respect to the screw shaft portion 36, the preload applied to the rolling elements 21a, 21b arranged in a double row can be adjusted. For this reason, the moment rigidity of the bearing device 5a can be appropriately ensured, preventing the main shaft 6a and the rotor hub 28 from vibrating while preventing the rotational resistance of the main shaft 6a and the rotor hub 28 from increasing unnecessarily.

[0088] Furthermore, in this example, a plurality of blades 3 are supported and fixed to a rotor hub 28 that is separate from the main shaft 6a of the generator 4a, and the rotor hub 28 and the main shaft 6a are rotatably supported with respect to the housing 2 by a bearing device 5a. For this reason, the axial length of the main shaft 6a can be made shorter compared to the axial length of the main shaft 6 in the first example, and the handleability during the transportation of the components of the wind power generation device 1a and during the assembly work can be improved.

[0089] Regarding the configuration and the operation and effect of other parts of the second example, they are the same as those of the first example.

[0090] [Third Example] The third example of the embodiment of the present disclosure will be described with reference to FIG. 3.

[0091] In the wind power generation device 1b of this example, the support structure of the outer ring 17a that constitutes the bearing device 5b with respect to the housing 2a has been changed from the second example.

[0092] The outer ring 17a has a fixing flange 46 that protrudes radially at an axially intermediate portion. The outer ring 17a is supported and fixed to the housing 2a by an outer ring fixing member 47 that is arranged so as to span the fixing flange 46 and the housing 2a.

[0093] In this example, the fixing flange 46 is constituted by a flat surface orthogonal to the central axis of the outer ring 17a at the radially outer portion of the side surface on the other axial side, and has an abutting surface 48 facing the other axial side, and has support holes 49 that penetrate axially at a plurality of circumferential positions in the radial intermediate portion.

[0094] Also, the housing 2a has a pedestal surface portion 50 that is constituted by a flat surface orthogonal to the central axis of the housing 2a at an end portion on one axial side, and has an abutting surface 48 facing the one axial side, and has screw holes 51 that open at a plurality of circumferential positions in the radial intermediate portion of the pedestal surface portion 50.

[0095] In this example, the abutting surface 48 is brought into contact with the pedestal surface portion 50, and the outer ring fixing member 47 composed of bolts is inserted through the support hole 49 and screwed into the screw hole 51, whereby the outer ring 17a is supported and fixed to the housing 2a.

[0096] Note that the structure in which the outer ring fixing member is arranged so as to span between the outer ring and the housing and the outer ring is supported and fixed to the housing is not limited to the structure of this example, and various structures can be adopted. For example, the outer ring fixing member composed of bolts is inserted axially from the other axial side through a through hole penetrating the flange portion provided in the housing in the axial direction and screwed into the support hole composed of a screw hole, whereby the outer ring can be supported and fixed to the housing. Alternatively, the outer ring fixing member composed of bolts may be inserted through a through hole and a support hole penetrating the flange portion provided in the housing in the axial direction, and a nut may be screwed onto the tip of the outer ring fixing member to support and fix the outer ring to the housing.

[0097] In the wind power generation device 1 of the second example, when the outer ring 17 is supported with respect to the housing 2, the central axis of the outer ring 17 of the bearing device 5, which is heavy, is accurately aligned with the central axis of the housing 2, and the central axis of the inner member 20a and the central axis of the main shaft 6a are accurately aligned. In this state, it is necessary to fit the outer ring 17 into the large-diameter cylindrical surface portion 7 of the housing 2 without rattling and engage the engaging shaft portion 35 with the engaging hole 40 (press-fitting or insertion), which is troublesome.

[0098] On the other hand, in this example, for example, first, with the central axis of the inner member 20a and the central axis of the main shaft 6a accurately aligned, the engaging shaft portion 35 is engaged (press-fitted or inserted) with the engaging hole 40, and the fixing flange 46 of the outer ring 17a is placed on the pedestal surface portion 50 of the housing 2a. Then, the central axis of the support hole 49 and the central axis of the screw hole 51 are made to substantially coincide, and the outer ring fixing member 47, which is a bolt, is inserted through the support hole 49 and screwed into the screw hole 51, whereby the outer ring 17a can be supported and fixed to the housing 2a. Therefore, according to the wind power generation device 1b of this example, the operation of supporting and fixing the outer ring 17a of the bearing device 5b to the housing 2a can be simplified.

[0099] For the configurations and functions and effects of other parts of the third example, they are the same as those of the first and second examples.

[0100] [Fourth Example] The fourth example of the embodiments of the present disclosure will be described with reference to FIGS. 4 and 5.

[0101] In the wind power generation device 1c of this example, the structure of the inner member 20b constituting the bearing device 5c has been changed from the third example.

[0102] The inner member 20b includes two inner ring elements 19c and 19b each having a single row of inner ring raceways 18a and 18b on the outer peripheral surface.

[0103] One of the two inner ring elements 19c and 19b, i.e., the inner ring element 19c, has a single row of inner ring raceway 18a, an inner ring fitting surface portion 38a provided on the outer peripheral surface and into which the other inner ring element 19b of the two inner ring elements is externally fitted, a rotating flange 39 that projects radially outward and to which the rotor hub 28 is coupled and fixed so as to be torque-transmittable, and an engaging hole 40 to which the engaging shaft portion 35 is engaged so as to be torque-transmittable. That is, one inner ring element 19c has a structure that integrally constitutes the inner ring element 19a on one axial side and the hub spindle 37 in the third example.

[0104] The inner ring raceway 18a is provided on the outer peripheral surface of the axial intermediate portion of one inner ring element 19c and has an arcuate bus shape in which the outer diameter increases as it goes toward one axial side.

[0105] The inner ring fitting surface portion 38a is provided on the outer peripheral surface of the portion of one inner ring element 19c that is located on the other axial side of the inner ring raceway 18a and is constituted by a cylindrical surface whose outer diameter does not change in the axial direction except for the end portion on one axial side.

[0106] The rotating flange 39 is provided at a portion of one of the inner ring elements 19c that protrudes axially on one side from the outer ring 17a. The rotating flange 39 has mounting holes 41 penetrating axially at a plurality of circumferential positions in the radial intermediate portion.

[0107] The engaging hole 40 is provided so as to penetrate axially through the center portion of one of the inner ring elements 19c.

[0108] The main shaft 6a and one of the inner ring elements 19c are combined so as to be able to transmit torque by non-circularly engaging the engaging shaft portion 35 and the engaging hole 40.

[0109] One of the inner ring elements 19c further includes a cylindrical pilot portion 43 at an end on one side in the axial direction.

[0110] The rotor hub 28 and one of the inner ring elements 19c are fixedly coupled by fitting the pilot portion 43 into the fitting recess 31 without play and passing a coupling member 44 through the through hole 34 and the mounting hole 41.

[0111] Furthermore, one of the inner ring elements 19c includes a stepped surface 52 that bends radially outward from an end on one side in the axial direction of the inner ring fitting surface portion 38a. The stepped surface 52 is composed of a flat surface that is orthogonal to the central axis of one of the inner ring elements 19c and faces the other side in the axial direction.

[0112] The other inner ring element 19b of the two inner ring elements 19c, 19b has basically the same structure as the inner ring element 19b on the other side in the axial direction of the third example. That is, the inner ring raceway 18b formed on the outer peripheral surface of the other inner ring element 19b has an arcuate generatrix shape in which the outer diameter increases toward the other side in the axial direction. The inner peripheral surface of the other inner ring element 19b is composed of a cylindrical surface whose inner diameter does not change axially except at the ends on both sides in the axial direction.

[0113] The other inner ring element 19b is fitted into the inner ring fitting surface portion 38a of one of the inner ring elements 19c without play. In this example, the other inner ring element 19b is press-fitted (including light press-fitting) into the inner ring fitting surface portion 38a.

[0114] In a state where the main shaft 6a and one inner ring element 19c are coupled and fixed, the other inner ring element 19b abuts the end face on one side in the axial direction against the stepped surface 52, and abuts the side surface on the other side in the axial direction against the inner diameter side stepped surface 15. In other words, the other inner ring element 19b is axially clamped between the stepped surface 52 and the inner diameter side stepped surface 15. Thereby, the axial movement of the other inner ring element 19b with respect to the one inner ring element 19c is blocked, and preload is applied to the rolling elements 21a, 21b arranged in a double row.

[0115] In the wind power generation device 1c of this example, by adjusting the axial clamping force of the other inner ring element 19b between the stepped surface 52 and the inner diameter side stepped surface 15, the preload applied to the rolling elements 21a, 21b arranged in a double row can be adjusted. Specifically, by adjusting the screwing amount of the nut 42 with respect to the screw shaft portion 36, the preload applied to the rolling elements 21a, 21b arranged in a double row can be adjusted.

[0116] The wind power generation device 1c of this example further includes a rotational speed detection device 53.

[0117] The rotational speed detection device 53 has a detected portion 54 whose magnetic characteristics change alternately and at equal intervals in the circumferential direction, and includes an encoder 55 supported and fixed to the inner member 20b, and a detection portion 56 facing the detected portion 54 and a sensor 57 supported and fixed to the housing 2a.

[0118] In this example, the encoder 55 is supported and fixed to the slinger 58 of the seal device 27c that closes the opening on the other side in the axial direction of the bearing inner space 26.

[0119] The seal device 27c includes a slinger 58 and a seal ring 59. That is, the seal device 27c is constituted by a combined seal ring.

[0120] The slinger 58 is formed by bending a metal plate having rust prevention properties such as a stainless steel plate into a substantially L-shaped cross section, and includes a cylindrical portion 60 that is press-fitted and externally fixed to the end portion on the other axial side of the other inner ring element 19b, and a circular ring portion 61 that is bent radially outward from the end portion on the other axial side of the cylindrical portion 60.

[0121] The seal ring 59 includes a core metal 62 and a sealing material 63.

[0122] The core metal 62 is formed into an annular shape as a whole by bending a metal plate such as a mild steel plate. The core metal 62 has a fitting cylinder portion 64 that is press-fitted and internally fixed to the end portion on the other axial side of the outer ring 17a, and a support plate portion 65 that is bent radially inward from the end portion on one axial side of the fitting cylinder portion 64.

[0123] The sealing material 63 is made of an elastic material such as an elastomer like rubber, and is bonded and fixed to the surface of the core metal 62 by vulcanization adhesion. The sealing material 63 has a sealing lip 66 whose tip portion is in sliding contact with the slinger 58.

[0124] In this example, the encoder 55 is formed into a hollow circular plate shape by a permanent magnet such as a rubber magnet or a plastic magnet. The encoder 55 is adhesively fixed to the side surface on the other axial side of the circular ring portion 61 of the slinger 58.

[0125] The detected portion 54 is provided on the side surface on the other axial side of the encoder 55, and is configured by arranging N poles and S poles alternately and at equal intervals in the circumferential direction.

[0126] The detection portion 56 is composed of a magnetic detection element such as a Hall element or a magnetoresistive element, and changes an output signal in response to a change in the magnetic characteristics of the portion of the detected portion 54 that faces the detected portion 54 itself.

[0127] The sensor 57 further has a holder 67 that holds the detection unit 56. The holder 67 is configured in a substantially columnar shape. In this example, the sensor 57 is supported and fixed to the housing 2a with the holder 67 inserted through a through hole 89 that radially penetrates one axial side portion of the housing 2a. The detection unit 56 is embedded in a portion of the holder 67 that axially faces the detected portion 54 of the encoder 55 in a state where the sensor 57 is supported and fixed to the housing 2a.

[0128] In the rotational speed detection device 53, as the encoder 55 rotates together with the main shaft 6a, the N pole and the S pole of the detected portion 54 of the encoder 55 alternately pass near the detection unit 56 of the sensor 57. Thereby, the direction of the magnetic flux passing through the detection unit 56 changes alternately. Based on the period of such a change in the direction of the magnetic flux, the rotational speed (number of rotations) of the main shaft 6a is obtained.

[0129] In the wind power generation device 1c of this example, based on the rotational speed of the main shaft 6a detected by the rotational speed detection device 53, the resistance value of the variable resistor of the generator 4 is adjusted, and feedback control can be performed to adjust the rotational speed of the main shaft 6a to a value with high power generation efficiency.

[0130] Regarding other configurations and operational effects of the fourth example, they are the same as those of the first to third examples.

[0131] [Fifth Example] The fifth example of the embodiment of the present disclosure will be described with reference to FIG. 6.

[0132] The wind power generation device 1d of this example includes a speed reducer 68 that decelerates the rotation of the inner member 20b constituting the bearing device 5c and transmits it to the main shaft 6b of the generator 4b. The speed reducer 68 has an input member 69 rotatably supported by the housing 2b by the bearing device 5a, and an output member 70 connected to the main shaft 6b so as to be torque-transmittable. In this example, the input member 69 constitutes a rotating member.

[0133] In this example, the input member 69 has a stepped cylindrical shape. Specifically, the input member 69 has, in order from one side in the axial direction, a threaded shaft portion 36, an engagement shaft portion 35, a flange portion 71, and a transmission side shaft portion 72.

[0134] The flange portion 71 has an outer diameter larger than the outer diameter of the engagement shaft portion 35. The flange portion 71 is constituted by a flat surface orthogonal to the central axis of the input member 69 on the side surface on one side in the axial direction, and has an inner diameter side stepped surface 15a facing one side in the axial direction.

[0135] The input member 69 and one inner ring element 19c constituting the inner member 20b are coupled and fixed by non-circularly engaging the engagement shaft portion 35 and the engagement hole 40 and screwing a nut 42 onto the threaded shaft portion 36. In a state where the input member 69 and one inner ring element 19c are coupled and fixed, the other inner ring element 19b constituting the inner member 20b abuts the stepped surface 52 with the end surface on one side in the axial direction, and abuts the inner diameter side stepped surface 15a with the side surface on the other side in the axial direction. Thereby, axial movement of the other inner ring element 19b with respect to one inner ring element 19c is blocked, and preload is applied to the rolling elements 21a, 21b arranged in a double row.

[0136] In this example, the output member 70 is configured in a columnar shape. The end portion on the other side in the axial direction of the output member 70 is connected via a joint 73 to the end portion on one side in the axial direction of the main shaft 6b of the generator 4b so as to be torque-transmittable.

[0137] The transmission 68 can be constituted by a speed increasing transmission that increases the rotational speed (number of revolutions) of the power input to the input member 69 and outputs it from the output member 70, a speed reducing transmission that reduces the rotational speed of the power input to the input member 69 and outputs it from the output member 70, or a stepped transmission or a continuously variable transmission capable of switching the transmission ratio between the input member 69 and the output member 70.

[0138] The structure of the transmission 68 is not particularly limited, and for example, structures such as a planetary gear type, a parallel shaft gear type, a chain type, and a belt type can be adopted.

[0139] In this example, the transmission 68 is constituted by a planetary gear type speed increasing gear. Specifically, in addition to the input member 69 and the output member 70, the transmission 68 includes a transmission housing 74, a carrier 75, a sun gear 76, a ring gear 77, and a plurality of planetary gears 78.

[0140] The transmission housing 74 is configured in a cylindrical shape with openings on both axial sides closed, and is supported and fixed inside the housing 2b. In this example, the transmission housing 74 is supported and fixed to the housing 2b via the generator housing 82 that constitutes the generator 4b. However, the transmission housing 74 can also be directly supported and fixed to the housing 2b by screwing or the like. The carrier 75, the sun gear 76, the ring gear 77, and the plurality of planetary gears 78 are accommodated inside the transmission housing 74.

[0141] Although detailed illustration is omitted, the transmission housing 74 is constituted by combining a plurality of parts, and in the process of combining the plurality of parts, the carrier 75, the sun gear 76, the ring gear 77, and the plurality of planetary gears 78 can be accommodated inside the transmission housing 74.

[0142] The carrier 75 is configured in a hollow circular plate shape, and is externally fitted and fixed around the transmission side shaft portion 72 of the input member 69 so as to rotate integrally with the input member 69.

[0143] The sun gear 76 is externally fitted and fixed to one axial end of the output member 70 so as to rotate integrally with the output member 70.

[0144] The ring gear 77 is arranged coaxially with the sun gear 76 around the sun gear 76, and is internally fitted and fixed to the inner peripheral surface of the transmission housing 74.

[0145] A plurality of planetary gears 78 are arranged at a plurality of circumferential positions between the sun gear 76 and the ring gear 77 and mesh with the sun gear 76 and the ring gear 77. Each planetary gear 78 is supported at a plurality of circumferential positions of the carrier 75 via a planetary shaft 79 and a radial bearing 80 so as to be capable of rotating (self-rotating) about its central axis. Specifically, the planetary shaft 79 is arranged parallel to the input member 69 and the output member 70, and one end portion on the axial direction one side is fitted and fixed in coupling holes 81 provided at a plurality of circumferential positions of the carrier 75. The radial bearing 80 is arranged between the outer peripheral surface of the other end portion on the axial direction other side of the planetary shaft 79 and the inner peripheral surface of the planetary gear 78.

[0146] The generator 4b includes a main shaft 6b, a generator housing 82, a rotor 11a, and a stator 12a.

[0147] The generator housing 82 is configured in a cylindrical shape with openings on both axial sides blocked, and is supported and fixed inside the housing 2b by screwing or the like. The rotor 11a and the stator 12a are accommodated inside the generator housing 82.

[0148] Although detailed illustration is omitted, the generator housing 82 is constituted by combining a plurality of components, and the rotor 11a and the stator 12a can be accommodated inside the generator housing 82 in the process of combining the plurality of components.

[0149] In this example, the transmission housing 74 and the generator housing 82 are coupled and fixed by a plurality of bolts 83 and a plurality of nuts 84. Specifically, through holes 86 that are provided at the other end in the axial direction of the transmission housing 74 and axially penetrate through a plurality of locations in the circumferential direction of the transmission-side flange portion 85 that protrudes radially outward, and through holes 88 that are provided at one end in the axial direction of the generator housing 82 and axially penetrate through a plurality of locations in the circumferential direction of the generator-side flange portion 87 that protrudes radially outward, the bolts 83 are inserted, and nuts 84 are screwed onto the tip ends of the bolts 83. Note that a cylindrical spacer 90 is disposed between the side surface on the other side in the axial direction of the transmission-side flange portion 85 and the side surface on one side in the axial direction of the generator-side flange portion 87 around each bolt 83.

[0150] The rotor 11a is externally fitted and fixed to the other end in the axial direction of the main shaft 6 so as to rotate integrally with the main shaft 6b.

[0151] The stator 12a is disposed coaxially with and rotatable relative to the rotor 11a around the rotor 11a, and is internally fitted and fixed to the inner peripheral surface of the generator housing 82.

[0152] In the wind power generation device 1d of this example, as wind blows against the plurality of blades 3, the inner member 20b is rotationally driven, and when the input member 69 rotates, the carrier 75 rotates, and the plurality of planetary gears 78 revolve around the central axis of the input member 69. When the plurality of planetary gears 78 revolve, based on the meshing of each planetary gear 78 with the ring gear 77, each planetary gear 78 rotates about its own central axis. As the plurality of planetary gears 78 revolve and rotate about their own central axes, the sun gear 76 is rotationally driven, and the output member 70 internally fitted and fixed to the sun gear 76 rotates. In this way, the rotation input to the input member 69 is increased in speed by the transmission 68 and output from the output member 70. The rotation of the output member 70 is transmitted to the main shaft 6b via the joint 73, and power generation is performed by the generator 4b.

[0153] Since the wind power generation device 1d in this example is provided with a speed changer 68, it is easy to adjust the rotational speed of the main shaft 6b to a value with high power generation efficiency.

[0154] The configurations and operational effects of other parts of the fifth example are the same as those of the first to fourth examples.

[0155] [Sixth Example] The sixth example of the embodiment of the present disclosure will be described with reference to FIG. 7.

[0156] The wind power generation device 1e in this example is different from the wind power generation device 1c of the fourth example in that a constant velocity joint 91 is provided between the inner member 20b of the bearing device 5c and the main shaft 6a. The constant velocity joint 91 includes a joint inner ring 92, a joint outer ring 93, and a plurality of balls 94.

[0157] The joint inner ring 92 has inner diameter side engagement grooves 95 at a plurality of circumferential locations on the outer peripheral surface, and is torque-transmittably connected to the main shaft 6a or the input member of a speed changer that torque-transmittably connects its output member to the main shaft 6a.

[0158] In this example, the outer peripheral surface of the joint inner ring 92 is configured as a partially convex spherical surface. The inner diameter side engagement grooves 95 are provided at a plurality of circumferentially equally spaced locations on the outer peripheral surface of the joint inner ring 92 so as to extend in the axial direction.

[0159] Further, the joint inner ring 92 has an engagement hole 96 that penetrates axially at the center. The engagement shaft portion 35 of the main shaft 6a is non-circularly engaged with the engagement hole 96. Specifically, the joint inner ring 92 is torque-transmittably connected to the main shaft 6a by spline-engaging a male spline portion provided on the outer peripheral surface of the engagement shaft portion 35 and a female spline portion provided on the inner peripheral surface of the engagement hole 96.

[0160] However, when implementing the wind power generation device according to one aspect of the present disclosure, a speed reducer can also be provided between the main shaft and the joint inner ring. In this case, the input member of the speed reducer is connected to the joint inner ring so as to be torque-transmittable, and the output member of the speed reducer is connected to the main shaft so as to be torque-transmittable.

[0161] The joint outer ring 93 has outer diameter side engagement grooves 97 at a plurality of circumferential positions on the inner circumferential surface, and is rotatably supported by the bearing device 5c with respect to the housing 2a. That is, in this example, the joint outer ring 93 constitutes a rotating member.

[0162] In this example, the joint outer ring 93 has a substantially bowl-shaped (substantially spherical) mouth portion 98 and a shaft portion 99.

[0163] The mouth portion 98 has a substantially cylindrical peripheral wall portion 100 and a substantially circular plate-shaped side wall portion 101 that closes the opening on one axial side of the peripheral wall portion 100. The outer diameter side engagement grooves 97 are provided at a plurality of circumferentially equally spaced positions on the inner circumferential surface of the peripheral wall portion 100 so as to extend in the axial direction.

[0164] The shaft portion 99 has a substantially cylindrical shape and protrudes axially outward from the central portion of the side surface on one axial side of the side wall portion 101.

[0165] The joint outer ring 93 and one inner ring element 19c constituting the inner member 20b are combined so as to be torque-transmittable by non-circularly engaging the shaft portion 99 and the engagement hole 40. For this purpose, in this example, the shaft portion 99 is provided with an engagement shaft portion 35a having a male spline portion on its outer peripheral surface at the other axial side portion, and a screw shaft portion 36a having a male thread portion on its outer peripheral surface at the end portion on one axial side. The joint outer ring 93 and one inner ring element 19c are spline-engaged with the male spline portion of the engagement shaft portion 35a and the female spline portion provided on the inner circumferential surface of the engagement hole 40, and are coupled and fixed so as to be torque-transmittable by screwing a nut 42a onto the screw shaft portion 36a.

[0166] In a state where the joint outer ring 93 and one inner ring element 19c are coupled and fixed, the other inner ring element 19b that constitutes the inner member 20b has an end face on one side in the axial direction abutted against a stepped surface 52 provided on the one inner ring element 19c, and a side surface on the other side in the axial direction abutted against a side surface on one side in the axial direction of the side wall portion 101. Thereby, axial movement of the other inner ring element 19b with respect to the one inner ring element 19c is blocked, and preload is applied to the rolling elements 21a and 21b arranged in a double row.

[0167] In addition, when implementing the wind power generation device according to one aspect of the present disclosure, in addition to, or instead of, non-circularly engaging the shaft portion of the joint outer ring with the engagement hole of the inner member (one inner element or the hub spindle), torque transmission between the joint outer ring and the inner member can also be enabled by spline-engaging a bearing-side face spline provided on an end face on the other side in the axial direction of the inner member with a joint-side face spline provided on a side surface on one side in the axial direction of the peripheral wall portion of the joint outer ring. In this case, instead of a structure in which the shaft portion of the joint outer ring is inserted into the engagement hole of the inner member from the other side in the axial direction and a nut is screwed onto an end portion on one side in the axial direction of the shaft portion, a structure can also be adopted in which a bolt is inserted into a central hole penetrating the inner member in the axial direction from one side in the axial direction, and a tip end portion of the bolt is screwed into a threaded hole provided in a side wall portion of the joint outer ring.

[0168] Each ball 94 is arranged one by one between an inner diameter side engagement groove 95 and an outer diameter side engagement groove 97 so as to be rollable along the inner diameter side engagement groove 95 and the outer diameter side engagement groove 97.

[0169] In the wind power generation device 1e of this example, a constant velocity joint 91 is provided between the inner member 20b of the bearing device 5c that rotatably supports the rotor hub 28 to which a plurality of blades 3 are supported and fixed, and the main shaft 6a of the generator 4a. Therefore, as the wind blows against the blade 3, when the rotary flange 39 tilts so as to fall in the axial direction due to the moment load applied to the bearing device 5c, the inclination of the central axis of the inner member 20b with respect to the central axis of the main shaft 6a can be absorbed by swinging the joint outer ring 93 with respect to the joint inner ring 92. That is, it is possible to prevent the central axis of the main shaft 6a from tilting with respect to the central axis of the inner peripheral surface of the housing 2a, and it is possible to suppress the occurrence of losses in the generator 4a.

[0170] Regarding the configurations and the operational effects of the other parts of the sixth example, they are the same as those of the fourth example.

[0171] The first to sixth examples of the embodiments of the present disclosure can be implemented in appropriate combinations as long as no contradictions occur.

Explanation of Reference Numerals

[0172] 1, 1a, 1b, 1c, 1d, 1e Wind power generation device 2, 2a, 2b Housing 3 Blade 4, 4a, 4b Generator 5, 5a, 5b, 5c Bearing device 6, 6a Main shaft 7 Large-diameter cylindrical surface portion 8 Small-diameter cylindrical surface portion 9 Outer diameter side step surface 10 Arm 11, 11a Rotor 12, 12a Stator 13 Small-diameter portion 14 Large-diameter portion 15, 15a Inner diameter side step surface 16a, 16b Outer ring raceway 17, 17a Outer ring 18a, 18b Inner ring raceway 19a, 19b, 19c Inner ring element Inner members 20, 20a, 20b Rolling elements 21a, 21b Outer diameter side retaining ring 22 Locking groove 23 Inner diameter side retaining ring 24 Cages 25a, 25b Bearing internal space 26 Sealing devices 27a, 27b, 27c Rotor hub 28 Base 29 Shaft portion 30 Fitting recess 31 Thick portion 32 Thin portion 33 Through hole 34 Engaging shaft portions 35, 35a Threaded shaft portions 36, 36a Hub spindle 37 Inner ring fitting surface 38 Rotating flange 39 Engaging hole 40 Mounting hole 41 Nuts 42, 42a Pilot portion 43 Coupling member 44 Fixed flange 46 Outer ring fixing member 47 Butting surface 48 Support hole 49 Pedestal surface 50 Threaded hole 51 Step surface 52 Rotation speed detection device 53 Detected portion 54 Encoder 55 Detection portion 56 Sensor 57 Slinger 58 Sealing ring 59 Cylindrical portion 60 Annular portion 61 Core metal 62 Sealing material 63 Fitting cylindrical portion 64 Support plate portion 65 Sealing lip 66 Holder 67 Transmission 69 Input member 70 Output member 71 Flange portion 72 Transmission side shaft portion 73 Joint 74 Transmission housing 75 Carrier 76 Sun gear 77 Ring gear 78 Planetary gear 79 Planet shaft 80 Radial bearing 81 Coupling hole 82 Generator housing 83 Bolt 84 Nut 85 Transmission side flange portion 86 Through hole 87 Generator side flange portion 88 Through hole 89 Through hole 90 Spacer 91 Constant velocity joint 92 Joint inner ring 93 Joint outer ring 94 Ball 95 Inner diameter side engagement groove 96 Engagement hole 97 Outer diameter side engagement groove 98 Mouse portion 99 Shaft portion 100 Peripheral wall portion 101 Side wall portion

Claims

1. A housing, a plurality of blades, a generator having a main shaft, a bearing device that rotatably supports the plurality of blades and a rotating member that is torque-transmittably connected to the main shaft or the main shaft with respect to the housing, comprising: the bearing device has a double-row outer raceway on the inner peripheral surface and an outer race supported by the housing, includes two inner race elements each having a single-row inner raceway on the outer peripheral surface, an inner member supported by the plurality of blades and the main shaft or the rotating member, and a plurality of rolling elements arranged in a double row between the double-row outer raceway and the single-row inner raceways of the two inner race elements and preloaded, comprising: a wind power generation device.

2. The plurality of blades are supported and fixed with respect to the main shaft or the rotating member, the two inner race elements are externally fitted to the main shaft or the rotating member, The wind power generation device according to claim 1.

3. further comprising a rotor hub to which the plurality of blades are supported and fixed, the main shaft or the rotating member has an engaging shaft portion, the inner member further comprises an inner race fitting surface portion provided on the outer peripheral surface and externally fitted with the two inner race elements, a rotating flange protruding radially outward and to which the rotor hub is torque-transmittably coupled and fixed, and an engaging hole to which the engaging shaft portion is torque-transmittably engaged, The wind power generation device according to claim 1.

4. further comprising a rotor hub to which the plurality of blades are supported and fixed, the main shaft or the rotating member has an engaging shaft portion, one of the two inner race elements has the single-row inner raceway, an inner race fitting surface portion provided on the outer peripheral surface and externally fitted with the other of the two inner race elements, a rotating flange protruding radially outward and to which the rotor hub is torque-transmittably coupled and fixed, and an engaging hole to which the engaging shaft portion is torque-transmittably engaged, The wind power generation device according to claim 1.

5. the outer race is snugly fitted into the housing without play, The wind power generation device according to claim 1.

6. the outer race has a fixing flange protruding radially outward and is supported and fixed to the housing by an outer race fixing member arranged to span between the fixing flange and the housing, The wind power generation device according to claim 1.

7. A rotation speed detection device further includes a detected portion whose magnetic characteristics change alternately and at equal intervals in the circumferential direction, an encoder supported and fixed to the inner member, and a sensor having a detection portion facing the detected portion and supported and fixed to the housing. The wind power generation device according to claim 1.

8. The wind power generation device further includes a transmission having an input member and an output member connected to the main shaft so as to be capable of torque transmission. The rotating member is constituted by the input member. The wind power generation device according to claim 1.

9. The wind power generation device further includes a constant velocity joint including a joint inner ring having inner diameter side engagement grooves at a plurality of locations in the circumferential direction on the outer peripheral surface, a joint outer ring having outer diameter side engagement grooves at a plurality of locations in the circumferential direction on the inner peripheral surface, and a plurality of balls arranged between the inner diameter side engagement grooves and the outer diameter side engagement grooves so as to be rollable along the inner diameter side engagement grooves and the outer diameter side engagement grooves. The joint inner ring is connected to the main shaft or an input member of a transmission that connects an output member thereof to the main shaft so as to be capable of torque transmission. The rotating member is constituted by the joint outer ring. The wind power generation device according to claim 1.

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