JP2011163420A - Bearing structure and direct drive type wind turbine generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve easiness in replacing a bearing and easiness in adjusting a clearance between rolling elements and an outer ring of the bearing. <P>SOLUTION: This bearing structure includes an inner ring 31 mounted to a main shaft 4; the outer ring 32 provided facing the inner ring 31; a bearing housing 6-1 holding the outer ring 32; cylindrical rollers 33 provided between the inner ring 31 and the outer ring 32; and a nut 34 fixing the inner ring 31. The main shaft 4 has a tapered surface 4a formed to be thinner in diameter toward the end of the main shaft 4. The inner ring 31 is pressed to the tapered surface 4a by the nut 34. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a bearing structure and a direct drive wind power generator using the same.

  One known type of wind turbine generator is a direct drive wind turbine generator. Classic wind power generators transmit the rotation of the wind turbine rotor to the generator by increasing the number of rotations using a gearbox, whereas in the direct drive wind power generator, the wind turbine rotor and generator are directly connected by the main shaft. Is done. A direct drive type wind turbine generator that can avoid mechanical loss in the gearbox by eliminating the gearbox is advantageous for improving the power generation efficiency.

  In the direct drive type wind turbine generator, the main shaft is large and the generator and the main shaft are directly connected. Therefore, special consideration is required in the design of the bearing structure that supports the main shaft. European Patent Application No. EP20144917 and Japanese Patent Application Laid-Open No. 2009-19625 discussing the bearing configuration in a direct drive type wind power generator. In these patent documents, the main shaft is supported by two bearings, the rear end plate of the generator is supported by a third bearing, and the front end plate configured to be easily bent is connected to the base plate. The structure to be disclosed is disclosed.

In addition, European Patent Application EP 1967731 discloses a spherical roller bearing (spherical) generally used in wind power generators.
In reference to roller bearings (SRB), clearance is inevitably generated in spherical roller bearings in the radial and axial directions, but it is argued that this is not compatible with the mechanical load applied to the drive train. As a structure for dealing with such a situation, European Patent Application No. EP1967671 reduces friction between a first assembly that forms a cavity that accommodates a rolling element and a second assembly that is fixed to the bearing housing. A self-aligning bearing is disclosed in which an anti-friction insert is inserted.

  On the other hand, according to the inventors' investigation, there are two other problems as described below in designing the bearing structure of the direct drive type wind power generator. The first problem is easy replacement of the bearing. Typically, the bearing is fitted into the main shaft by shrink fitting. On the other hand, the bearing that supports the main shaft may need to be replaced when some trouble occurs in the wind turbine generator or during regular maintenance. In such a case, it is not preferable that the bearing is fitted by shrink fitting, which makes it difficult to replace the bearing. Improvement of the ease of replacement of the bearing is particularly important in a direct drive type wind power generator installed on the ocean.

  The second problem is easy adjustment of the clearance between the rolling element (ball or roller) of the bearing that supports the main shaft and the outer ring. In a direct drive type wind power generator in which the main shaft and the generator rotor are directly connected, it is desirable that the clearance between the rolling elements of the bearing and the outer ring be small in order to ensure the clearance between the stator and the rotor of the generator. . This is because if the clearance between the rolling element of the bearing and the outer ring is large, the vibration of the main shaft increases, and the rotor of the generator may come into contact with the stator. On the other hand, it is not preferable that the clearance between the stator and the rotor of the generator is too small. This is because if the clearance between the stator and the rotor of the generator is too small, the problem of the temperature difference between the inner ring and the outer ring cannot be dealt with. Specifically, during the operation of the wind turbine generator, the temperature of the bearing rises, but the temperature rise is larger in the inner ring than in the outer ring. When the temperature of the inner ring becomes relatively higher than the temperature of the outer ring, the thermal expansion of the inner ring becomes larger than that of the outer ring, and as a result, the mechanical load acting on the rolling elements increases. This is not preferable because the life of the rolling element is shortened. Thus, the clearance between the rolling element of the bearing and the outer ring is not preferable whether it is too large or too small, and needs to be adjusted optimally. In order to optimally adjust the clearance between the rolling elements of the bearing and the outer ring, it is desirable that the clearance is easily adjusted.

European Patent Application EP20144917 JP 2009-19625 A European Patent Application EP1966731

  Accordingly, an object of the present invention is to provide a bearing structure for improving at least one of the ease of replacement of a bearing and the ease of adjusting the clearance between a rolling element and an outer ring of the bearing.

  The means for achieving the above object will be described below. In order to clarify the correspondence between the description of [Claims] and the description of [Mode for Carrying Out the Invention], the technical matters included in the means include [Mode for Carrying Out the Invention]. ] Is added with the numbers and symbols used in []. However, the added numbers and symbols should not be used for the interpretation of the technical scope of the invention described in [Claims].

  In one aspect of the present invention, the bearing structure includes a rotating shaft (4), first inner rings (31) and (52) attached to the rotating shaft (4), and outer sides of the first inner rings (31 and 52). In addition, a first outer ring (32, 53, 53b) provided to face the first inner ring (31, 52) and a bearing housing (6-1, 6) for housing the first outer ring (32, 53, 53b). -2), a first rolling element (33, 55) provided between the first inner ring (31, 52) and the first outer ring (32, 53, 53b), and the first inner ring (31, 52). And inner ring fixing members (34, 57, 57a to 57c) to be fixed. The rotating shaft (4) has tapered surfaces (4a, 4b) formed such that the diameter of the rotating shaft (4) becomes thinner as it approaches the end of the rotating shaft (4). The first inner rings (31, 52) are pressed against the tapered surfaces (4a, 4b) by the inner ring fixing members (34, 57, 57a to 57c).

  In one embodiment, the bearing structure further includes a second inner ring (51) attached to the rotating shaft (4) adjacent to the first inner ring (52), a second inner ring (51), and a first outer ring ( 53) and a second rolling element (54) provided between them. The first inner ring (52), the first rolling element (55), and the first portion of the first outer ring (53) constitute a radial bearing that supports a load in the radial direction, while the second inner ring (51) and the second inner ring (51) A thrust bearing that supports a load in the axial direction is constituted by the rolling element (54) and the second portion of the first outer ring (53).

In such a bearing structure, a first clearance (δ ₂ ) provided between the second inner ring (51) and the rotating shaft (4) is provided between the first rolling element and the first outer ring (53). It is preferably larger than the second clearance (δ ₃ ).

In another embodiment, the outer ring of the radial bearing and the outer ring of the axial bearing may be prepared separately. In this case, the bearing structure includes a second outer ring (53a) provided on the outer side of the second inner ring (51) so as to face the second inner ring (51), a second inner ring (51), and a second outer ring ( 53a) and a second rolling element (54). The first inner ring (52), the first rolling element (55), and the first outer ring (53b) form a radial bearing that supports a radial load. The second inner ring (51), the second rolling element (54), and the like. A thrust bearing that supports a load in the axial direction is configured by the second outer ring (53b). In this case, a first clearance (δ ₂ ) provided between the second outer ring (53a) and the bearing housing (6-2) is provided between the first rolling element (55) and the first outer ring (53b). It is preferable that it is larger than the obtained second clearance (δ ₃ ).

In the bearing structure, a hydraulic oil supply path (41a) reaching the outer peripheral surface of the first outer ring (53b) is formed in the bearing housing (6-2), and the first outer ring ( It is preferable that the second clearance (δ ₃ ) can be adjusted by applying hydraulic pressure to the outer peripheral surface of 53b).

  In one embodiment, a screw adjacent to the tapered surface (4a, 4b) is formed on the rotary shaft (4) on the end side of the rotary shaft (4), and the inner ring fixing members (34, 57) are screwed with the screw. It has a nut to do.

  In one embodiment, the inner ring fixing member includes a ring (57a) inserted into the rotating shaft (4), a fixing member (57b) that fixes the ring (57a) to the rotating shaft (4), and a ring (57a). And a bolt (57c) penetrating in the axial direction of the rotating shaft (4), and the first inner ring (52) is pressed against the tapered surface (4b) by the bolt (57c).

  In one embodiment, the first inner ring (52) is formed such that its diameter decreases as it approaches the end of the rotation shaft (4), and an inner peripheral surface that comes into contact with the tapered surfaces (4a, 4b), and a diameter A tapered ring (52a) having an outer peripheral surface formed to have a constant diameter, and an inner peripheral surface formed to be in contact with the outer peripheral surface of the tapered ring (52a) and to have a constant diameter. A straight inner ring (52b). In this case, the first rolling element (55) is provided between the straight inner ring (52b) and the first outer ring (53).

  In order to absorb the inclination of the rotating shaft (4), it is preferable that the bearing housing (6-1) and the first outer ring (32) are joined so as to be relatively displaceable. In this case, in one embodiment, an elastic body (24, 25) may be provided between the bearing housing (6-1) and the first outer ring (32).

  In order to absorb the inclination of the rotation shaft (4), the first outer ring (32) includes an inner member (32a) and an outer member (32b) positioned outside the inner member (32a). (32a) and the outer member (32b) may be joined so as to be relatively displaceable. In this case, the first rolling element (33) is provided between the first inner ring (31) and the inner member (32a). In this case, in one embodiment, an elastic body (32c) is provided between the inner member (32a) and the outer member (32b). Instead, the outer member (32b) is provided with a lubricating oil sump (32d) that reaches the outer peripheral surface of the inner member (32a), and the outer peripheral surface of the inner member (32a) and / or the inner periphery of the outer member (32b). A groove (32e) may be provided on the surface, and the lubricating oil reservoir (32d) and the groove (32e) may be filled with a lubricating fluid.

  In order to improve the exchangeability, the first inner ring (31) can be divided into a plurality of members (61, 62) in the circumferential direction of the rotating shaft (4), and the first outer ring (32) can be divided into the rotating shaft ( It is preferable that the member can be divided into a plurality of members (71, 72) in the circumferential direction 4).

  Such a bearing structure is suitable for rotatably supporting the main shaft (4) of the direct drive type wind power generator (1).

  According to the present invention, it is possible to improve at least one of the ease of replacement of the bearing that supports the main shaft and the ease of adjusting the clearance between the rolling elements of the bearing and the outer ring.

It is a perspective view which shows the structure of the direct drive type wind power generator in one Embodiment of this invention. It is sectional drawing which shows the structure of the direct drive type wind power generator in one Embodiment of this invention. It is sectional drawing which shows the structure of the bearing in one Embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is sectional drawing which shows the structure of the bearing in other embodiment of this invention. It is a top view which shows the structure of the bearing in other embodiment of this invention. It is a front view which shows the structure of the bearing in other embodiment of this invention.

  1 and 2 are views showing the structure of a direct drive type wind power generator 1 according to an embodiment of the present invention. With reference to FIG. 1, the wind turbine generator 1 includes a tower 2, a nacelle pedestal 3 mounted on the tower 2, and a main shaft 4. A wind turbine rotor (not shown) including a rotor head and wind turbine blades is coupled to one end of the main shaft 4, and a generator 7 is coupled to the other end. The stator casing 11 of the generator 7 is connected to the nacelle pedestal 3 by a torque support 8, and the torque acting on the stator casing 11 in the circumferential direction of the main shaft 4 is supported by the torque support 8.

  As shown in FIG. 2, the nacelle base 3 is provided with two bearing housings 6-1 and 6-2, and the main shaft 4 is provided inside the bearing housings 6-1 and 6-2. The bearings 5-1 and 5-2 are rotatably supported.

  The generator 7 includes a stator 12 and a generator rotor 13. The stator 12 is fixed to the stator casing 11. The generator rotor 13 includes a field magnet 14 and a rotor plate 15 that supports the field magnet 14, and the rotor plate 15 is coupled to a sleeve 9 inserted into the main shaft 4. The stator casing 11 is supported by two generator bearings 16 provided on the main shaft 4, and the main shaft 4 is rotatable with respect to the stator casing 11.

  FIG. 3 is a sectional view showing the structure of the bearings 5-1, 5-2 and the bearing housings 6-1, 6-2. First, the structure of the bearing 5-1 and the bearing housing 6-1 which are located on the side close to the wind turbine rotor will be described. The bearing 5-1 includes an inner ring 31, an outer ring 32, and a cylindrical roller 33 sandwiched between them. The cylindrical roller 33 is held by a separator holder (not shown). On the other hand, the bearing housing 6-1 includes an annular body 21, a plate 22, and a bolt 23 that couples the plate 22 to the annular body 21. The outer ring 32 of the bearing 5-1 is in contact with the inner peripheral surface of the annular body 21, and is sandwiched and held between the protruding portion provided on the annular body 21 and the plate 22.

  The bearing structure of this embodiment has one feature in the structure in which the inner ring 31 is attached to the main shaft 4. A taper surface 4 a is formed on the main shaft 4 so that the diameter of the main shaft 4 decreases as the end of the main shaft 4 is approached. On the other hand, the inner ring 31 is formed so that the inner diameter becomes smaller as it approaches the end of the main shaft 4, and the inner peripheral surface of the inner ring 31 is pressed against the tapered surface 4a. Further, a screw is formed adjacent to the tapered surface 4a, and a nut 34 is screwed to the screw. The nut 34 has a function as an inner ring fixing member that fixes the inner ring 31. That is, when the nut 34 is tightened, the inner ring 31 is pressed against the tapered surface 4a, and thereby the inner ring 31 is fixed.

  According to such a structure, the inner ring 31 of the bearing 5-1 can be easily attached to or detached from the main shaft 4, and the ease of replacement of the bearing 5-1 can be improved. In a general wind power generator in which the inner ring and the main shaft are fastened by shrink fitting, a lot of labor is required to remove the inner ring and the main shaft. However, in the structure of FIG. 3, the inner ring 31 is easily removed by applying a force to the inner ring 31 in a direction parallel to the central axis of the main shaft 4 and toward the end of the main shaft 4 after removing the nut 34. be able to. On the other hand, the inner ring 31 can be easily attached to the main shaft 4 by tightening the nut 34 after inserting the inner ring 31 into the main shaft 4 and pressing the inner ring 31 against the tapered surface 4a.

In addition, the clearance δ ₁ (or the interval between the inner ring 31 and the outer ring 32) between the cylindrical roller 33 and the outer ring 32 can be easily adjusted by the tightening degree of the nut 34. If ask displacing the inner ring 31 is tightened strongly nut 34 away from the end of the main shaft 4 can be easily narrowed clearance [delta] _1. Also, if displaced in the direction towards the inner ring 31 on the end of the main shaft 4 on loosening the nut 34 can be easily widen the clearance [delta] _1.

  On the other hand, the bearing 5-2 and the bearing housing 6-2 located on the side close to the generator 7 have the following structure. The bearing 5-2 has a structure in which the axial load Fa and the radial load Fr are supported by separate rolling elements. Specifically, the first inner ring 51, the second inner ring 52, A common outer ring 53, a ball 54, and a cylindrical roller 55 are provided. The balls 54 are arranged between the first inner ring 51 and the common outer ring 53, and the cylindrical rollers 55 are arranged between the second inner ring 52 and the common outer ring 53. The bearing housing 6-2 includes an annular body 41, a plate 42, and a bolt 43 that couples the plate 42 to the annular body 41.

  Here, the first inner ring 51, the common outer ring 53, and the ball 54 constitute a thrust ball bearing that supports only the load Fa in the axial direction, and the second inner ring 52, the common outer ring 53, and the cylindrical roller 55 are radial. A radial roller bearing that supports only the load Fr in the direction is configured. When the axial load Fa acts on the main shaft 4, the axial load Fa is transmitted to and supported by the bearing housing 6-2 via the first inner ring 51, the balls 54, and the common outer ring 53. On the other hand, when the radial load Fr acts on the main shaft 4, the radial load Fr is transmitted to and supported by the bearing housing 6-2 via the second inner ring 52, the cylindrical roller 55, and the common outer ring 53.

  In order to receive both the axial load Fa and the radial load Fr, a double row bearing (for example, a double row tapered roller bearing) is often used. A single row load in which the load is concentrated can occur. When a single-row load occurs, the life of the bearing is shortened. However, in the bearing 5-2 of the present embodiment, the axial load Fa and the radial load Fr are received by separate rolling elements, so that the problem of single-row load does not occur.

  The common outer ring 53 of the bearing 5-2 is in contact with the inner peripheral surface of the annular body 41, and is held between the projecting portion provided on the annular body 41 and the plate 42.

The first inner ring 51 is sandwiched and held by a step 4 c provided on the main shaft 4 and a nut 56. Here, the first inner ring 51, the clearance [delta] ₂ is sandwiched to be kept between the inner peripheral surface and the main shaft 4 thereof. As described below, the clearance [delta] ₂ is present, a common outer ring 53 and the ball 54 and the first inner ring 51, is important in order to function as a thrust bearing for supporting only the load Fa axial direction.

  On the other hand, the inner peripheral surface of the second inner ring 52 is attached to the main shaft 4 by being pressed against a tapered surface 4 b provided on the main shaft 4 by a nut 57. Specifically, the main shaft 4 is formed with a tapered surface 4 b so that the diameter of the main shaft 4 decreases as the end of the main shaft 4 is approached. On the other hand, the second inner ring 52 is formed so that the inner diameter becomes smaller as it approaches the end of the main shaft 4, and the inner peripheral surface of the second inner ring 52 is pressed against the tapered surface 4b. Further, a screw is formed adjacent to the tapered surface 4b, and a nut 57 is screwed to the screw. The nut 57 has a function as an inner ring fixing member that fixes the second inner ring 52. That is, when the nut 57 is tightened, the second inner ring 52 is pressed against the tapered surface 4b, whereby the second inner ring 52 is fixed.

The second inner ring 52 and the cylindrical roller 55 are attached to the main shaft 4 such that a clearance δ ₃ exists between the cylindrical roller 55 and the common outer ring 53. Here, the clearance δ ₃ between the cylindrical roller 55 and the common outer ring 53 is adjusted to be smaller than the clearance δ ₂ between the inner peripheral surface of the first inner ring 51 and the main shaft 4. It clearance [delta] ₃ is smaller than the clearance [delta] ₂ is functionally important bearing 5-2. The clearance [delta] ₃ is greater than the clearance [delta] _2, when a load Fa in the radial direction is applied to the bearing 5-2, the inner peripheral surface of the first inner ring 51 before the cylindrical roller 55 and the common outer ring 53 is in contact And the main shaft 4 come into contact with each other, and a radial load Fr acts on the first inner ring 51, the common outer ring 53, and the ball 54 that should function as an axial bearing. In the bearing 5-2 of the present embodiment, by the clearance [delta] ₃ is smaller than the clearance [delta] _2, when a load Fa in the radial direction is applied to the bearing 5-2, the inner peripheral surface and the main shaft of the first inner ring 51 The cylindrical roller 55 and the common outer ring 53 come into contact with each other before the contact with 4, and the second inner ring 52, the cylindrical roller 55, and the common outer ring 53 function as a radial bearing as desired. Thus, the bearing 5-2 of this embodiment, the axial bearing and the radial bearing separation is realized by clearance [delta] ₃ is smaller than the clearance [delta] _2.

  According to the above-described structure of the bearing 5-2, the first inner ring 51 and the second inner ring 52 can be easily attached to or removed from the main shaft 4 as in the case of the bearing 5-1, and the bearing 5-2 can be easily replaced. Can be improved. By removing the nut 57 and applying a force to the second inner ring 52 in a direction parallel to the central axis of the main shaft 4 and toward the end of the main shaft 4, the second inner ring 52 can be easily removed. Furthermore, if the nut 56 is removed, the 1st inner ring | wheel 51 can also be removed easily. On the other hand, the first inner ring 51 is inserted into the main shaft 4, the nut 56 is tightened, the second inner ring 52 is inserted into the main shaft 4, and then the nut 57 is tightened, whereby the first inner ring 51 and the second inner ring 52 are moved. It can be easily attached to the main shaft 4.

Further, according to the structure of the bearing 5-2 described above, adjustment of the clearance [delta] ₃ between the cylindrical rollers 55 common outer ring 53 is also easy. As described above, the optimal adjustment of the clearance δ ₃ between the cylindrical roller 55 and the common outer ring 53 prevents contact between the generator rotor 13 and the stator 12 of the generator 7, while the second inner ring 52 and the common outer ring. It is important to deal with the 53 temperature difference problem. According to the structure of the bearing 5-2 illustrated in FIG. 3, the clearance δ ₃ (or the interval between the second inner ring 52 and the common outer ring 53) between the cylindrical roller 55 and the common outer ring 53 is set by tightening the nut 57. Can be easily adjusted. This is preferable for optimally adjusting the clearance δ ₃ between the cylindrical roller 55 and the common outer ring 53.

  In the structure of the bearing 5-2 in FIG. 3, a tapered roller may be used instead of the ball 54. In the above description, the bearing housing 6-1 is the wind turbine rotor side and the bearing housing 6-2 is the generator side. Conversely, the bearing housing 6-1 is the generator side and the bearing housing 6-2 is the wind turbine rotor. It can be used as a side. In the above description, the annular bodies (21, 41) and the outer rings (32, 53) in the bearing housings 6-1 and 6-2 are fixed by the plates (22, 41) and the bolts (23, 43). However, the annular body (21, 41) and the outer ring (32, 5) may be shrink-fitted, and the gap between the annular body (21, 41) and the outer ring (32, 53) may be eliminated to prevent backlash. In that case, the plates (22, 41) and the bolts (23, 43) are unnecessary.

  FIG. 4 is a cross-sectional view showing the structure of the bearing 5-2 in another embodiment. In the structure of FIG. 4, the second inner ring 52 is attached to the main shaft 4 by a combination of a ring 57 a and bolts 57 b and 57 c instead of the nut 57. The ring 57 a is inserted into the main shaft 4 adjacent to the second inner ring 52. The bolt 57 b is inserted into the ring 57 a in the radial direction of the main shaft 4, and is screwed into a female screw provided on the ring 57 a and the main shaft 4. On the other hand, the bolt 57 c is inserted into the ring 57 a in the axial direction of the main shaft 4. Here, in FIG. 4, the bolts 57 b are illustrated by simple lines in order to show that the bolts 57 b and 57 c are at different positions in the circumferential direction of the ring 57 a. In the structure of FIG. 4, the ring 57a is fixed to the main shaft 4 by a bolt 57b, while the second inner ring 52 is pressed against the tapered surface 4b by a bolt 57c that is screwed into the ring 57a. It is attached to the main shaft 4.

  Also in the structure of FIG. 4, the first inner ring 51 and the second inner ring 52 can be easily attached to or detached from the main shaft 4, and the ease of replacement of the bearing 5-2 can be improved. By loosening the bolt 57b and removing the ring 57a and the bolt 57c from the main shaft 4, a force is applied to the second inner ring 52 in a direction parallel to the central axis of the main shaft 4 and toward the end of the main shaft 4. The second inner ring 52 can be easily removed. On the other hand, after the second inner ring 52 is inserted into the main shaft 4, the ring 57a is attached to the main shaft 4 by bolts 57b, and the second inner ring 52 can be easily attached to the main shaft 4 by tightening the bolts 57c. .

According to the structure of the bearing 5-2 of Figure 4, the adjustment of the clearance [delta] ₃ between the cylindrical rollers 55 common outer ring 53 is also easy. In the structure of FIG. 4, the clearance δ ₃ (or the interval between the second inner ring 52 and the common outer ring 52) between the cylindrical roller 55 and the common outer ring 53 can be easily adjusted by tightening the bolts 57c. Specifically, the second inner ring 52 is tightened strongly bolt 57c if caused to displace in a direction away from the end of the main shaft 4 can be easily narrowed clearance [delta] _3. Also, the second inner race 52 on loosening the bolts 57c if caused to displace in the direction towards the end of the main shaft 4 can be easily widen the clearance [delta] _3. This is preferable for optimally adjusting the clearance δ ₃ between the cylindrical roller 55 and the common outer ring 53.

  The structure in which the second inner ring 52 is pressed against the tapered surface 4b and fixed by the combination of the ring 57a and the bolts 57b and 57c shown in FIG. 4 can also be applied to the structure in which the inner ring 31 of the bearing 5-1 is fixed. is there. Further, similarly to the case of FIG. 3, the annular body 41 and the outer ring 53 can be shrink-fitted and the plate 42 and the bolt 43 can be used.

  FIG. 5 is a cross-sectional view showing a modification of the structure of the bearing 5-2, in particular, the structure of the second inner ring 52 in still another embodiment. In the structure of FIGS. 3 and 4, the second inner ring 52 is formed so that the inner diameter becomes smaller as it approaches the end of the main shaft 4, but as shown in FIG. Two members: a tapered ring 52a and a straight inner ring 52b may be used. The tapered ring 52a has a structure in which the inner diameter becomes smaller toward the end of the main shaft 4 while the outer diameter is constant. On the other hand, the straight inner ring 52b has a constant inner diameter. Such a structure is preferable in order to facilitate the manufacture of the second inner ring 52. The second inner ring 52 shown in FIGS. 3 and 4 has a special structure and cannot be manufactured by a general inner ring manufacturing method. On the other hand, in the second inner ring 52 having a two-part structure shown in FIG. 5, the straight inner ring 52b can be manufactured by a general inner ring manufacturing process, and the processing of the tapered ring 52a is not difficult. In this manner, the second inner ring 52 can be easily manufactured by adopting the two-divided structure shown in FIG.

  FIG. 6A is a cross-sectional view showing a structure of a bearing 5-2 in still another embodiment. In the structure of the bearing 5-2 in FIGS. 3 and 4, the common outer ring 53 common to the thrust bearing and the radial bearing is used. However, in the structure of FIG. A first outer ring 53a and a second outer ring 53b are used. The ball 54 is inserted between the first inner ring 51 and the first outer ring 53a, and the first inner ring 51, the ball 54, and the first outer ring 53a constitute a thrust bearing. On the other hand, the cylindrical roller 55 is inserted between the second inner ring 52 and the second outer ring 53b, and the second inner ring 52, the cylindrical roller 55, and the second outer ring 53b constitute a radial bearing.

In the arrangement of FIG. 6A, rather than between the first inner ring 51 with the main shaft 4, the clearance [delta] ₂ is provided between the annular body 41 of the bearing housing 6-2 and the first outer ring 53a. Further, the clearance [delta] ₃ is provided between the cylindrical rollers 55 and the second outer ring 53b. The clearance [delta] ₃ is adjusted to be smaller than the clearance [delta] _2. This is to realize separation of the axial bearing and the radial bearing, similarly to the configuration of the bearing 5-2 in FIGS. Clearance [delta] ₃ of axial bearing and the radial bearing separation is achieved by less than the clearance [delta] _2.

In the configuration of FIG. 6A as well, the first inner ring 51 and the second inner ring 52 can be easily attached and detached as in the configurations of FIGS. 3 and 4, and the ease of replacement of the bearing 5-2 is improved. Further, it can be adjusted clearance [delta] ₃ by tightness of the nut 57, it is easy to adjust the clearance [delta] _3.

  In addition, in the configuration of FIG. 6A, separate outer rings: the first outer ring 53 a and the second outer ring 53 b are used for the thrust bearing and the radial bearing, so that low cost can be realized. As shown in FIGS. 3 and 4, in the configuration in which the common outer ring 53 common to the thrust bearing and the radial bearing is used, it is necessary to manufacture an outer ring having a special structure. On the other hand, in the configuration of FIG. 6A in which separate outer rings are used for the thrust bearing and the radial bearing, an outer ring having a general structure can be adopted, and thus the cost can be reduced.

  In the structure of the bearing 5-2 in FIG. 6A, a tapered roller can be used instead of the ball 54. 3 and 4, the annular body 41 and the outer ring 53b can be shrink-fitted so that the plate 42 and the bolt 43 are not used.

Where separate outer ring in the thrust bearing and the radial bearing is used, as shown in Figure 6B, the cylindrical rollers 55 and the clearance [delta] ₃ between the second outer ring 53b may be adjusted by the hydraulic pressure. In the structure of FIG. 6B, the hydraulic oil supply path 41a that reaches the outer peripheral surface of the second outer ring 53b is formed in the annular body 41 of the bearing housing 6-2, and the hydraulic oil is filled in the hydraulic oil supply path 41a. Hydraulic pressure is applied to the outer peripheral surface of the second outer ring 53b via the hydraulic oil supply path 41a. By exerted hydraulic pressure to the outer peripheral surface of the second outer ring 53b, the cylindrical rollers 55 and the clearance [delta] ₃ between the second outer ring 53b is adjusted.

  As shown in FIGS. 1 and 2, in the above-described embodiment, bearing housings 6-1 and 6-2 that accommodate two bearings 5-1 and 5-2 are separately prepared. This is an unavoidable configuration for providing the large-scale wind power generator 1. However, if the bearing housings 6-1 and 6-2 are formed separately, the main shaft 4 tends to be inclined. When the main shaft 4 is tilted, a large piece of contact is exerted on the bearings 5-1 and 5-2, resulting in a problem that the life of the bearings 5-1 and 5-2 is shortened.

  In order to cope with the problem of the inclination of the main shaft 4, it is preferable that the outer ring and the bearing housing are elastically coupled and relatively displaceable. 7A to 7C are cross-sectional views showing a preferred embodiment of a bearing structure in which the outer ring 32 of the bearing 5-1 and the bearing housing 6-1 are elastically coupled.

  In the bearing structure of FIG. 7A, a plurality of grooves 21a are formed on the inner peripheral surface of the annular body 21 of the bearing housing 6-1, so that the rigidity of the portion of the annular body 21 that contacts the outer ring 32 is weakened. Thereby, the bearing housing 6-1 and the outer ring | wheel 32 are supported so that relative displacement is possible. 7A, the inclination of the main shaft 4 is absorbed by the relative displacement between the bearing housing 6-1 and the outer ring 32.

  Further, as shown in FIGS. 7B and 7C, an elastic body may be sandwiched between the annular body 21 and the outer ring 32 of the bearing housing 6-1. 7B, an elastic sheet 24 is sandwiched between the annular body 21 and the outer ring 32 of the bearing housing 6-1. On the other hand, in the structure of FIG. 7C, a plurality of annular grooves are formed on the inner peripheral surface of the annular body 21, and an annular elastic ring 25 is fitted in each of the grooves. The bearing housing 6-1 and the outer ring 32 are supported by the elastic sheet 24 or the elastic ring 25 so as to be relatively displaceable.

  7A to 7C, the coupling between the outer ring 32 of the bearing 5-1 and the bearing housing 6-1 is illustrated. However, in the structure of FIGS. 3 and 4, the common outer ring of the bearing 5-2 is illustrated. 53 and the bearing housing 6-2 may be elastically coupled and relatively displaceable. 6A and 6B, the first outer ring 53a and the second outer ring 53b may be elastically coupled to the bearing housing 6-2 and relatively displaceable.

  Further, as shown in FIGS. 8A and 8B, the outer ring is configured to include two members that can be relatively displaced, and when the two members are relatively displaced, the inclination of the main shaft 4 is reduced. It may be absorbed. For example, in the structure of FIG. 8A, the outer ring 32 includes an inner member 32a, an outer member 32b, and an elastic sheet 32c. A groove for accommodating the cylindrical roller 33 is formed on the inner peripheral surface of the inner member 32a, and the outer peripheral surface of the inner member 32a has a shape that becomes a part of the cylindrical surface. The inner peripheral surface of the outer member 32b is located opposite to the outer peripheral surface of the inner member 32a, and has a shape that becomes a part of the cylindrical surface. The elastic sheet 32c is inserted between the inner member 32a and the outer member 32b. 8A, the inner member 32a and the outer member 32b are held so as to be relatively displaceable by the elastic sheet 32c, whereby the inclination of the main shaft 4 is absorbed.

  On the other hand, in the structure of FIG. 8B, the outer ring 32 is configured such that the inner member 32a is in contact with the outer member 32b. Each of the outer peripheral surface of the inner member 32a and the inner peripheral surface of the outer member 32b has a shape that becomes a part of the cylindrical surface. In addition, as shown in FIG. 8C, a groove 32e is formed on the outer peripheral surface of the inner member 32a, and as shown in FIG. 8B, the outer member 32b communicates with the outer peripheral surface of the inner member 32a. A lubricating oil reservoir 32d is formed. The lubricating oil reservoir 32d and the groove 32e are filled or supplied with a lubricating fluid such as grease or lubricating oil. With such a structure, grease or lubricating oil is held between the inner member 32a and the outer member 32b. In the structure of FIG. 8B, the inner member 32a and the outer member 32b can be relatively displaced by grease or lubricating oil, whereby the inclination of the main shaft 4 is absorbed. Instead of forming the groove 32e on the outer peripheral surface of the inner member 32a, a groove may be provided on the inner peripheral surface of the outer member 32b. In addition to forming the groove 32e on the outer peripheral surface of the inner member 32a, the outer side You may provide a groove | channel in the internal peripheral surface of the member 32b. It is also possible to adopt a structure in which the annular body 21 and the outer ring 32b are shrink-fitted and the plate 22 and the bolt 23 are not used.

  The configuration in which the outer ring includes two members that can be relatively displaced is also applicable to the common outer ring 53 in FIGS. 3 and 4 and the first outer ring 53a and the second outer ring 53b in FIGS. 6A and 6B.

  In order to improve the ease of replacement of the bearing 5-1, it is desirable that the bearing 5-1 has a structure that can be divided into a plurality of members in the circumferential direction. FIG. 9 is a front view showing the structure of the splittable bearing 5-1. The inner ring 31 includes two inner ring members 61 and 62 and a bolt 63 that fastens them. A notch 61a is formed at one end of the inner ring member 61, and a notch 62a is formed at one end of the inner ring member 62. By inserting a bolt 63 into these notches 61a, 62a, the inner ring members 61 and 62, Are connected. Similarly, the outer ring 32 includes two outer ring members 71 and 72 and a bolt 73 that fastens them. A cutout 71a is formed at one end of the outer ring member 71, and a cutout 72a is formed at one end of the outer ring member 72. By inserting bolts 73 into the cutouts 71a and 72a, the outer ring members 71 and 72 Are connected. In this case, the plate 22 and the separator holder (not shown) are also divided in the circumferential direction. Since the bearing 5-1 has a structure that can be divided into a plurality of members in the circumferential direction, the bearing 5-1 is attached to the main shaft 4 and the bearing housing 6-1, or from the main shaft 4 and the bearing housing 6-1. It becomes easy to remove. The structure of the bearing that can be divided in the circumferential direction as shown in FIG. 9 is also applicable to the bearing 5-2.

  Although various embodiments of the present invention have been described above, the present invention can be implemented with various obvious modifications, and various combinations of the structures described above are possible. Those skilled in the art will appreciate that this is possible. For example, it will be obvious to those skilled in the art that the structure of the bearing 5-1 and the structure of the bearing 5-2 described above can be arbitrarily combined to be mounted on the wind power generator 1. Furthermore, although the bearing structure of the present invention is particularly suitable for the direct drive type wind power generator 1, it will be understood by those skilled in the art that it can be applied to other mechanical devices.

1: Wind power generator 2: Tower 3: Nacelle pedestal 4: Main shaft 4a, 4b: Tapered surface 4c: Step 5-1, 5-2: Bearing 6-1, 6-2: Bearing housing 7: Generator 8: Torque Support 9: Sleeve 11: Stator casing 12: Stator 13: Generator rotor 14: Field magnet 15: Rotor plate 16: Generator bearing 21: Ring body 21a: Groove 22: Plate 23: Bolt 24: Elastic body sheet 25: Elastic ring 31: Inner ring 32: Outer ring 32a: Inner member 32b: Outer member 32c: Elastic sheet 32d: Lubricating oil reservoir 32e: Groove 33: Cylindrical roller 34: Nut 41: Annular body 41a: Hydraulic oil supply path 42: Plate 43: Bolt 51: First inner ring 52: Second inner ring 52a: Tapered ring 52b: Straight inner ring 53: Common outer ring 53 : First outer ring 53b: Second outer ring 54: Ball 55: Cylindrical roller 56, 57: Nut 57a: Ring 57b, 57c: Bolt 61, 62: Inner ring member 61a, 62a: Notch 63: Bolt 71, 72: Outer ring member 71a 72a: Notch 73: Bolt

Claims (20)

A rotation axis;
A first inner ring attached to the rotating shaft;
A first outer ring provided on the outer side of the first inner ring so as to face the first inner ring;
A bearing housing that houses the first outer ring;
A first rolling element provided between the first inner ring and the first outer ring;
An inner ring fixing member for fixing the first inner ring;
The rotating shaft has a tapered surface formed such that the diameter of the rotating shaft becomes thinner as it approaches the end of the rotating shaft;
The bearing structure in which the first inner ring is pressed against the tapered surface by the inner ring fixing member. The bearing structure according to claim 1,
Furthermore,
A second inner ring attached to the rotating shaft adjacent to the first inner ring;
A second rolling element provided between the second inner ring and the first outer ring;
A radial bearing that supports a load in a radial direction is configured by the first portion of the first inner ring, the first rolling element, and the first outer ring,
A bearing structure in which a thrust bearing that supports a load in an axial direction is configured by the second inner ring, the second rolling element, and the second portion of the first outer ring. The bearing structure according to claim 2,
A bearing structure in which a first clearance provided between the second inner ring and the rotating shaft is larger than a second clearance provided between the first rolling element and the first outer ring. The bearing structure according to claim 1,
Furthermore,
A second inner ring attached to the rotating shaft adjacent to the first inner ring;
A second outer ring provided on the outer side of the second inner ring so as to face the second inner ring;
A second rolling element provided between the second inner ring and the second outer ring,
A radial bearing that supports a load in a radial direction is configured by the first inner ring, the first rolling element, and the first outer ring,
A bearing structure in which a thrust bearing that supports a load in an axial direction is configured by the second inner ring, the second rolling element, and the second outer ring. The bearing structure according to claim 4,
Furthermore,
The bearing housing houses the first outer ring and the second outer ring;
A bearing structure in which a first clearance provided between the second outer ring and the bearing housing is larger than a second clearance provided between the first rolling element and the first outer ring. The bearing structure according to claim 5,
The bearing housing is formed with a hydraulic oil supply path that reaches the outer peripheral surface of the first outer ring,
A bearing structure capable of adjusting the second clearance by applying hydraulic pressure to the outer peripheral surface of the first outer ring via the hydraulic oil supply path. The bearing structure according to any one of claims 1 to 6,
A screw is formed on the rotating shaft adjacent to the tapered surface on the end side of the rotating shaft,
The inner ring fixing member includes a nut that is screwed with the screw. The bearing structure according to any one of claims 1 to 6,
The inner ring fixing member is
A ring inserted into the rotating shaft;
A fixing member for fixing the ring to the rotating shaft;
A bolt that penetrates the ring in the axial direction of the rotating shaft,
The bearing structure in which the first inner ring is pressed against the tapered surface by the bolt. A bearing structure according to any one of claims 1 to 8,
The first inner ring is
A tapered ring having an inner peripheral surface that is formed so as to decrease in diameter as it approaches the end of the rotating shaft and is in contact with the tapered surface, and an outer peripheral surface that is formed so that the diameter is constant,
A straight inner ring having an inner peripheral surface that is in contact with an outer peripheral surface of the tapered ring and has a constant diameter;
A bearing structure in which the first rolling element is provided between the straight inner ring and the first outer ring. The bearing structure according to any one of claims 1 to 9,
A bearing structure in which the bearing housing and the first outer ring are joined so as to be relatively displaceable. The bearing structure according to claim 10,
A bearing structure in which an elastic body is provided between the bearing housing and the first outer ring. The bearing structure according to any one of claims 1 to 9,
The first outer ring is
An inner member;
An outer member located outside the inner member;
The first rolling element is provided between the first inner ring and the inner member;
The bearing structure in which the inner member and the outer member are joined so as to be relatively displaceable. The bearing structure according to claim 12,
A bearing structure in which an elastic body is provided between the inner member and the outer member. The bearing structure according to claim 12,
The outer member is provided with a lubricating oil sump that reaches the outer peripheral surface of the inner member,
Grooves are provided on the outer peripheral surface of the inner member and / or the inner peripheral surface of the outer member,
A bearing structure in which the lubricating oil reservoir and the groove are filled with a lubricating fluid. The bearing structure according to claim 1, wherein the first inner ring can be divided into a plurality of members in a circumferential direction of the rotating shaft,
A bearing structure in which the first outer ring can be divided into a plurality of members in the circumferential direction of the rotating shaft. A generator,
A main shaft having one end joined to the wind turbine rotor and the other end joined to the rotor of the generator;
A first inner ring attached to the main shaft;
A first outer ring provided on the outer side of the first inner ring so as to face the first inner ring;
A bearing housing that houses the first outer ring;
A first rolling element provided between the first inner ring and the first outer ring;
An inner ring fixing member for fixing the first inner ring;
The main shaft has a tapered surface formed such that the diameter of the main shaft becomes thinner as it approaches the end of the main shaft;
The direct drive type wind turbine generator in which the first inner ring is pressed against the tapered surface by the inner ring fixing member. The direct drive wind power generator according to claim 16,
Furthermore,
A second inner ring attached to the main shaft adjacent to the first inner ring;
A second rolling element provided between the second inner ring and the first outer ring;
A radial bearing that supports a load in a radial direction is configured by the first portion of the first inner ring, the first rolling element, and the first outer ring,
A direct drive type wind power generator in which a thrust bearing that supports a load in an axial direction is configured by the second inner ring, the second rolling element, and the second portion of the first outer ring. A direct drive wind power generator according to claim 17,
A direct drive type wind turbine generator in which a first clearance provided between the second inner ring and the main shaft is larger than a second clearance provided between the first rolling element and the first outer ring. The direct drive wind power generator according to claim 16,
Furthermore,
A second inner ring attached to the main shaft adjacent to the first inner ring;
A second outer ring provided on the outer side of the second inner ring so as to face the second inner ring;
A second rolling element provided between the second inner ring and the second outer ring,
A radial bearing that supports a load in a radial direction is configured by the first inner ring, the first rolling element, and the first outer ring,
A direct drive type wind power generator in which a thrust bearing that supports a load in an axial direction is configured by the second inner ring, the second rolling element, and the second outer ring. The direct drive wind power generator according to claim 19,
Furthermore,
The bearing housing houses the first outer ring and the second outer ring;
A direct drive type wind power generator in which a first clearance provided between the second outer ring and the bearing housing is larger than a second clearance provided between the first rolling element and the first outer ring.

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