WO2010013341A1

WO2010013341A1 - Swing structure

Info

Publication number: WO2010013341A1
Application number: PCT/JP2008/063776
Authority: WO
Inventors: 彰博寺町; 白井　武樹; 飯田　勝也; 智幸会田
Original assignee: Thk株式会社
Priority date: 2008-07-31
Filing date: 2008-07-31
Publication date: 2010-02-04

Abstract

Provided is a swing structure which realizes production of a structure having a large swing diameter easily and inexpensively, which is easy to carry, and which realizes optimal distribution of load capacity in 360˚ around the center of swing according to various kinds of use. The swing structure is composed of a lower structure (4), an upper swing body (3) disposed swingably with respect to the lower structure (4), and a swing bearing mechanism (5) interposed between the lower structure (4) and the upper swing body (3). The swing bearing mechanism (5) is composed of an endless ring-formed fixed ring (7) and at least three slide blocks (8). The endless ring-formed fixed ring (7) is composed of a plurality of circular track rails (70) which have a fixed curvature and which are arranged continuously on the lower structure (4). The three slide blocks (8) are assembled to the fixed ring (7) through many rolling bodies (80) and movable freely along the fixed ring (7) while carrying the upper swing body (3).

Description

Swivel structure

The present invention relates to a turning structure for supporting an upper turning body so as to be turnable with respect to a lower structure. For example, a nacelle in which a wind turbine is rotatably supported with respect to a tower of a wind power generation apparatus according to a wind direction. The present invention relates to a turning structure or a turning structure for turning an upper frame including a driver's seat with respect to a truck frame in a construction machine represented by a power shovel or the like.

For example, in a wind turbine generator, a nacelle that houses a windmill and a generator that is rotationally driven by the windmill is mounted on the top of the tower, and this nacelle is attached to the tower according to the wind direction so that the windmill receives wind force from the front. On the other hand, it is configured to perform yaw turning (turning on a substantially horizontal plane).

And as a structure for yawing the nacelle with respect to the tower, a swivel bearing in which an inner ring and an outer ring are combined via a plurality of balls or rollers is used, and either the inner ring or the outer ring is a tower, and the other is It is fixed to the nacelle (Japanese Patent Laid-Open No. 2007-107411).

On the other hand, in construction machines such as power shovels and cranes, an upper frame having a driver's seat and a counterweight is turnably mounted on a track frame that is a lower structure. (Japanese Patent Laid-Open No. 2005-61574).

The slewing bearing used in the slewing structure includes an outer ring in which a rolling surface of a rolling element is formed along an inner circumferential surface, and an inner ring in which a rolling surface facing the rolling surface on the outer ring side is formed on the outer circumferential surface. And a large number of rolling elements that roll while applying a load between the outer ring and the inner ring. Either a ball or a roller can be used as the rolling element, but when a roller is used instead of a ball, the inner ring and the outer ring are not separated from each other by a load. On the other hand, it is necessary to arrange the rollers in a cross-roller structure, or to make the rolling surfaces in double rows and to make the inclination directions of the rollers different on each rolling surface.
JP2007-107411A JP-A-2005-61574

In recent years, the wind turbine generator has been increased in size to increase the rated output, and accordingly, the wind turbine diameter has increased and the nacelle tends to increase in size. For this reason, the diameter of the slewing bearing used in the slewing structure is remarkably increased, and there is a case where a huge slewing bearing having a diameter of 4 m or more is required.

However, the production of the inner ring and outer ring of such a huge slewing bearing requires special equipment, and has to procure a large-diameter steel material suitable for production, which increases production costs. was there. In recent years, natural energy such as wind power generation has attracted attention due to the relationship with the global warming problem, and there is a tendency for demand for wind power generation equipment to increase. There was a problem that it was impossible to produce in large quantities and supply could not keep up with demand. In addition, such a large-sized slewing bearing is difficult to transport, and when further enlargement proceeds, it may be impossible to transport. Such problems also apply to the turning structure of construction machines.

By the way, the conventional slewing bearing has a continuous arrangement of rolling elements between the inner ring and the outer ring, and even if the load acts from any direction of 360 ° around the slewing bearing, the load is equalized. It was possible to load. However, assuming a situation in which a slewing bearing is actually used, for example, in a slewing structure of a nacelle of a wind power generator, since a windmill is attached to one side of the nacelle, a large load acts locally on the slewing bearing. Will be. Also, in the swing structure of a construction machine, since the counter weight is mounted on the upper frame of the construction machine, the swing bearing that supports the swing of the upper frame is locally corresponding to the mounting position of the counter weight. A heavy load is acting. That is, in an actual turning structure in which the upper turning body is supported with respect to the lower structure, a load is often applied locally to the inner ring and outer ring of the turning bearing. It is considered that the need to load equally in any direction of 360 ° is poor.

The present invention has been made in view of such problems, and the object of the present invention is to make it possible to easily produce a structure with a large turning diameter at low cost and to carry it easily. Is to provide.

Another object of the present invention is to provide a turning structure capable of optimally distributing the load-loading ability around 360 ° around the turning center in accordance with various uses of the turning structure.

That is, the present invention relates to a lower structure, an upper swing body arranged to be rotatable with respect to the lower structure, and a swing bearing mechanism interposed between the lower structure and the upper swing body. It is the turning structure which consists of. The slewing bearing mechanism is composed of a plurality of arc-shaped track rails having a constant curvature, and an endless annular fixed ring in which these track rails are continuously arranged on the lower structure, and a large number of rolling elements. And at least three or more slide blocks that can be freely moved along the fixing ring in a state where the upper rotating body is supported.

According to the present invention as described above, the slewing bearing mechanism is composed of an endless annular fixing ring assembled from a plurality of arcuate track rails and at least three or more slide blocks assembled to the fixing rail. Therefore, even when a very large-diameter turning structure is required, the turning structure can be easily constructed by increasing the number of arc-shaped track rails and the number of slide blocks. That is, unlike the conventional slewing bearing, there is no need for special equipment for producing large-diameter inner rings and outer rings, and it is not necessary to prepare a steel material having a length suitable for the circumference of the fixed ring. Therefore, it is possible to easily and inexpensively produce a turning structure having a large turning diameter.

In the present invention, the number of slide blocks to be assembled to the fixing ring can be changed as appropriate according to the diameter of the fixing ring, the weight of the upper swing body, etc., as long as the number is three or more. It is. Also, the reason for limiting the number of slide blocks to at least three or more is that depending on the arrangement of the slide blocks with respect to the fixed ring, if there are only two slide blocks, it is difficult to determine the pivot center of the upper swing body, and the swing motion of the upper swing body is not possible. This is because it becomes stable.

Further, since the fixing ring is formed in an annular shape by arranging a plurality of arc-shaped track rails in the lower structure, it can be handled as individual arc-shaped track rails until being arranged in the lower structure, It becomes possible to carry it easily.

Further, since the plurality of slide blocks assembled to the fixing ring can be arranged at arbitrary positions on the circumference of the fixing ring, the slide block is arranged with respect to the load application point from the upper swing body to the lower structure. Therefore, it is possible to increase the load carrying capacity more easily than the conventional slewing bearing.

It is a front view which shows the wind power generator which can apply the turning structure of this invention. It is the schematic which shows the turning structure of the wind power generator shown in FIG. It is a perspective view which shows an example of the turning bearing mechanism in the turning structure of this invention. It is a perspective view which shows the combination of the arc-shaped track rail and slide block which comprise the turning bearing mechanism shown in FIG. It is a semi-sectional view showing another example of an arcuate track rail. It is a top view which shows the example which arrange | positioned four slide blocks to a fixing ring at equal intervals, and divided | segmented into two groups from which a preload amount differs. It is a top view which shows the example which arrange | positioned six slide blocks to a fixing ring at equal intervals, and was divided | segmented into four groups from which the amount of preload differs. It is a top view which shows the example divided | segmented into two groups from which the 5 slide blocks are arrange | positioned at a non-uniform space | interval in a fixing ring, and the amount of preload differs.

Hereinafter, the turning structure of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an example of a wind turbine generator 1 to which the turning structure of the present invention can be applied. The wind turbine generator 1 includes a windmill 2, a nacelle 3 that houses a generator driven by the windmill 2, and a tower 4 that supports the nacelle 3 in a yaw-turnable manner. The windmill 2 is rotatably held at a predetermined height from the ground by a tower 4, and is rotated by wind energy to rotationally drive a generator housed in the nacelle 3. The generator converts rotational energy generated in the windmill 2 into electrical energy, and transmits the electrical energy to ground equipment such as a transformer through a power transmission line stored in the tower 4.

Rotating bearing mechanism 5 is provided between nacelle 3 as the upper rotating body and the uppermost part of tower 4 as the lower structure in order to forcibly wind windmill 2 upwind.

As shown in FIG. 2, the slewing bearing mechanism 5 includes an endless annular fixing ring 7 disposed via a substrate plate 6 with respect to the uppermost portion of the tower 4, and the fixing ring 7 via a large number of balls. A plurality of slide blocks 8 assembled to each other, and a turntable 9 that supports the nacelle 3 is fixed to the slide blocks 8.

Further, a tooth row is provided along the circumferential direction on the outer peripheral surface of the fixing ring 7, and a pinion gear 10 is engaged with the tooth row. The pinion gear 10 is configured to be arbitrarily rotated by a motor 11 mounted on the turning table 9, and when the motor 11 rotates the pinion gear 10, the turning table 9 makes a yaw turn with respect to the tower 4. The nacelle 3 that rotatably supports the windmill 2 can be directed in an arbitrary direction.

FIG. 3 is a perspective view showing the fixed ring 7 and the slide block 8 constituting the slewing bearing mechanism 5. The fixing ring 7 is formed by continuously arranging a plurality of arc-shaped track rails 70, and each track rail 70 is formed in an arc shape with a constant curvature. In the example shown in FIG. 3, the fixed ring 7 is formed by continuously arranging three track rails 70. A tooth row 71 that meshes with the pinion gear 10 is directly formed on the outer peripheral side surface of each track rail 70 by machining. That is, the fixing ring 7 functions as a gear ring having external teeth. It is also possible to provide a tooth row on the inner peripheral side surface of the track rail 70 and to engage the pinion gear 10 with the tooth row.

FIG. 4 is a perspective view showing details of each track rail 70 formed in an arc shape and the slide block 8 assembled to the track rail 70. The track rail 70 is formed in an arc shape with a predetermined curvature radius R with respect to the center O of the fixed ring 7, and a cross section perpendicular to the longitudinal direction is formed in a substantially rectangular shape. Two ball rolling grooves 72 are respectively formed along the longitudinal direction on the inner peripheral side surface and the outer peripheral side surface, and a total of four ball rolling grooves 72 are formed. Further, the above-described tooth row 71 is formed below the outer peripheral side surface of the track rail 70.

On the other hand, the slide block 8 has an infinite circulation path of the ball 80 rolling in the ball rolling groove 72 of the track rail 70, and the ball 80 circulates in the infinite circulation path, so that the slide block 8 is It is possible to move continuously along the track rail 70. As shown in FIG. 3, the two track rails 70 that are in contact with each other have continuous ball rolling grooves 72, and the slide block 8 moves from the track rail 70 to the adjacent track rail 70 and moves. can do. Therefore, the slide block 8 can freely circulate around the fixing ring 7 composed of a plurality of track rails 70.

In the combination of the track rail 70 and the slide block 8 shown in FIG. 4, the slide block 8 is assembled to the track rail 70 via a large number of balls 80, but a large number of rollers are used instead of the balls 80. It is also possible to use it. When the roller is used, the allowable load load of the slide block can be set larger, which is advantageous when the weight of the upper swing body is large.

The slide block 8 is assembled to the track rail 70 by a ball train rolling on four ball rolling grooves 72 formed on the track rail 70, and the track rail 70 and slide block of each ball train are assembled. The contact direction with respect to 8 is inclined at 45 ° with respect to the substrate plate 6, for example. That is, the slide block 8 can move along the track rail 70 while applying a load acting in any direction except the circumferential direction of the fixing ring 7. From this, it is possible to apply a preload to the ball 80 provided in the slide block 8, and the preload amount can be adjusted by changing the ball diameter. By adjusting the preload amount as described above, when a load is applied to the slide block 8, the displacement amount of the slide block 8 relative to the track rail 70, and hence the displacement amount of the turning table 9 relative to the substrate plate 6 can be reduced. Is possible.

Although three or more slide blocks 8 are assembled to the fixing ring 7 (four in the example shown in FIG. 3), these slide blocks 8 are fixed to a single turning table 9 (FIG. 2). reference). That is, this turning table 9 corresponds to the upper turning body in the present invention. As a result of the plurality of slide blocks 8 assembled to the fixing ring 7 being fixed to the turning table 9, the turning table 9 is only allowed to turn around the center O of the fixing ring 7.

FIG. 5 shows another example of the arcuate track rail 70 constituting the fixing ring 7. In the example shown in FIG. 5, the track rail 70 is not directly fixed to the uppermost substrate plate 6 of the tower 4, but is fixed to the substrate plate 6 via a gear ring 73 having a tooth row 71 on the outer peripheral side surface. Has been. Therefore, the tooth rail 71 is not formed on the track rail 70 itself, and the pinion gear 10 is configured to mesh with the tooth row 71 of the gear ring 73. The gear ring 73 may be formed in an endless annular shape, but in consideration of difficulty in transportation and production, it is preferable to configure a plurality of arc-shaped parts in combination like the track rail 70. 5 denotes a bolt that passes through the gear ring 73 and fastens the track rail 70 to the substrate plate 6.

In the swivel structure configured as described above, the swivel table 9 to which the slide block 8 is fixed is allowed only to swivel around the center O of the fixed ring 7. When the meshing pinion gear 10 is rotated by the motor 11, the turning table 9 performs a turning motion with respect to the substrate plate 6 according to the amount of rotation of the motor 11. That is, the nacelle 3 of the wind power generator 1 as the upper swing body can be swung on the tower 4 as the lower structure, and the windmill can be directed in an arbitrary direction.

As the wind power generator 1 is increased in size, a fixed ring 7 having a diameter of 4 m or more is required as the slewing bearing mechanism 5 for supporting the yaw slewing of the nacelle 3. In this regard, since the fixed ring 7 is composed of a plurality of arcuate track rails 70 in the turning structure of the present invention, even if the fixed ring 7 has a larger diameter, the circumferential direction of the fixed ring 7 By increasing the number of divisions, that is, the number of arc-shaped track rails 70, it is possible to easily cope with the problem. Moreover, since the steel material for producing the fixing ring 7 can be divided into the number of the arc-shaped track rails 70, it is easy to obtain. Therefore, according to the turning structure of the present invention, it is possible to easily and inexpensively produce a turning structure having a large turning diameter.

Further, since the fixed ring 7 is constructed by combining a plurality of arc-shaped track rails 70, the slewing bearing mechanism 5 can be easily transported even when a slewing structure having a large slewing diameter is constructed. is there.

Furthermore, the plurality of slide blocks 8 assembled to the fixing ring 7 may be arranged at equal intervals along the circumferential direction of the fixing ring 7, but it is not always necessary to arrange them at equal intervals, and the upper swing Arbitrary arrangements can be adopted according to the point of action and the magnitude of the load from the body to the lower structure. For example, in the wind turbine generator 1 shown in FIGS. 1 and 3, since the windmill is supported at the tip of the nacelle 3, the turning table 9 that supports the nacelle 3 has a maximum load at a position close to the windmill 2. It is thought that is acting. For this reason, the slide blocks 8 are not arranged at equal intervals along the circumferential direction of the fixed ring 7, but are arranged in a concentrated manner at the point of application of a large load, so that It is possible to reduce the number of assembling bases of the slide block 8 and reduce the cost required for manufacturing the turning structure.

By the way, when the endless annular fixing ring 7 is configured by combining the plurality of arc-shaped track rails 70 in this way, the roundness of the fixing ring 7 is ensured if the positioning of each arc-shaped track rail 70 is poor. Becomes difficult. When the roundness of the fixing ring 7 deteriorates, when the three or more slide blocks 8 assembled to the fixing ring 7 are fixed to a single turning table 9, the turning table 9 becomes heavy. When the roundness of the fixing ring 7 is extremely bad, the turning ring 9 cannot be rotated.

As a measure for avoiding such a problem, the plurality of slide blocks 8 assembled to the fixing ring 7 are divided into a plurality of groups along the circumferential direction of the fixing ring 7, and the slide blocks 8 are provided for each group. It is conceivable to vary the preload amount of the ball 80.

FIG. 6 is a plan view of the slewing bearing mechanism 5 showing a case where four slide blocks 8 a to 8 d are combined with the fixing ring 7. These four slide blocks are divided into two groups G1 and G2, and the amount of preload applied to the balls of the slide blocks 8a and 8b belonging to the group G1 is the ball of the slide blocks 8c and 8d belonging to the group G2. It is set to be larger than the preload amount given to.

In the slide blocks 8a and 8b belonging to the group G1, since the preload amount of the ball is set large, even if a large load acts on the slide blocks 8a and 8b from the turning table 9, the slide blocks 8a and 8b are fixed. There is no significant displacement with respect to the ring 7. On the other hand, in the slide blocks 8c and 8d belonging to the group G2, the preload amount of the ball is set to be small or no preload is applied, so that the slide blocks 8c and 8d are attached to the fixed ring 7 more than the slide blocks 8a and 8b in the group G1. On the other hand, it can be displaced greatly.

For this reason, even if the mounting position accuracy of each track rail 70 forming the fixing ring 7 on the substrate plate 6 is low and the roundness of the fixing ring 7 is poor, the turning table 9 has the slide block 8a of the group G1. , 8b on the fixed ring 7 as a reference, during such movement of the rotary table 9, the slide blocks 8c, 8d of the group G2 are fixed while absorbing the roundness error of the fixed ring 7. It moves on the ring 7. Therefore, even if the roundness of the fixing ring 7 is poor, it is possible to give a smooth and smooth turning motion to the turning table 9.

On the other hand, FIG. 7 is a plan view of the slewing bearing mechanism 5 showing a case where six slide blocks 8a to 8f are combined with the fixed ring 7. FIG. These six slide blocks are divided into four groups G1 to G4. The groups G1 and G3 have one slide block, and the groups G2 and G3 have two slide blocks. Among these groups G1 to G4, the amount of preload given to the ball of the slide block 8a belonging to the group G1 is the maximum compared to other groups, and the amount of preload given to the ball of the slide block 8d belonging to the group G3 is the other. Minimal compared to the group. Further, the preload amount applied to the balls of the

slide blocks

8b, 8c, 8e, and 8f belonging to the groups G2 and G4 is about the middle of the preload amounts in the groups G1 and G3.

As shown in the example of FIG. 7, among a plurality of groups G1 to G4 formed by dividing a plurality of slide blocks 8a to 8f, a group G1 that gives the maximum preload amount to the ball of the slide block; The group G3 to which the minimum amount of preload is given is opposed to the center of the fixing ring 7. As described above, when the group G1 having the maximum preload amount and the group G3 having the minimum preload amount are arranged with the center of the fixing ring 7 interposed therebetween, these groups do not have the center of the fixing ring 7 interposed therebetween. Compared to the case where the fixing ring 7 is adjacent on the circumference, the error amount of the roundness of the fixing ring 7 that can be absorbed by the slide block 8d having the minimum preload amount can be increased. Therefore, even if the roundness of the fixing ring 7 is poor, it is possible to cause the turning table 9 to perform the turning motion more smoothly.

This is the same in the example shown in FIG. 6 in which the four slide blocks 8a to 8d are divided into two groups. That is, in the example shown in FIG. 6, the group G1 that gives the maximum preload amount to the ball of the slide block and the group G2 that gives a smaller preload amount face each other across the center of the fixing ring 7. Therefore, it is possible to increase the error amount of the roundness of the fixing ring 7 that can be absorbed by the slide blocks 8c and 8d having the minimum preload amount.

Further, from the viewpoint of reliably receiving the load acting on the swivel table 9 and suppressing the displacement of the swivel table 9, the group to which the maximum preload amount is given to the ball 80 of the slide block 8 is the swivel table. 9 is preferably located immediately below the point of load application to 9. For example, if the slewing bearing mechanism 5 shown in FIG. 7 is applied to the slewing structure of the wind turbine generator 1 shown in FIGS. 1 and 2, the slide block 8a of the group G1 is closest to the windmill 2. Next, the arrangement of the slide blocks 8a to 8f with respect to the turning table 9 is determined.

6 and 7 show an example in which a plurality of slide blocks are arranged at equal intervals along the circumferential direction of the fixing ring 7. On the other hand, FIG. 8 shows an example in which a plurality of slide blocks 8a to 8e are arranged at unequal intervals along the circumferential direction of the fixing ring 7, and are fixed to the turning table in this arrangement state. The five slide blocks 8a to 8e assembled to the fixing ring are divided into two groups G1 and G2, and the amount of preload applied to the balls of the slide blocks 8a to 8c belonging to the group G1 belongs to the group G2. It is set to be larger than the preload amount applied to the balls of the slide blocks 8d and 8e. The slide blocks 8a to 8c belonging to the group G1 are arranged at equal intervals. The arrangement interval is set smaller than the interval between the slide block 8c belonging to the group G1 and the slide block 8d belonging to the group G2. . Further, the arrangement interval of the slide blocks 8d and 8e belonging to the group G2 is also set smaller than the interval between the slide block 8c belonging to the group G1 and the slide block 8d belonging to the group G2.

The arrangement of the slide block shown in FIG. 8 is effective for reliably receiving the load acting on the turning table 9. That is, by providing the group G1 directly below the point of application of the load to the turning table 9, it is possible to provide a turning bearing mechanism that is optimal for the weight arrangement of the upper turning body supported by the turning table. It is possible to avoid useless arrangement and reduce the number of slide blocks incorporated in the fixing ring.

In the example shown in FIG. 8, the group G1 that gives the maximum preload amount to the ball of the slide block and the group G2 that gives a smaller preload amount face each other across the center of the fixing ring 7. Thus, it is possible to increase the error amount of the roundness of the fixing ring 7 that can be absorbed by the slide blocks 8d and 8e having the minimum preload amount. That is, even if the roundness of the fixing ring 7 is poor, it is possible to give a smooth turning motion without difficulty to the turning table 9.

Claims

The lower structure (4), the upper structure (3) arranged to be rotatable with respect to the lower structure (4), and between the lower structure (4) and the upper structure (3) In a swivel structure comprising a swivel bearing mechanism (5) interposed between
The slewing bearing mechanism (5)
An endless fixing ring (7) comprising a plurality of arc-shaped track rails (70) having a constant curvature, and these track rails (70) are continuously arranged on the lower structure (4);
At least three groups that are assembled to the fixing ring (7) via a large number of rolling elements (80) and are movable freely along the fixing ring (7) in a state where the upper revolving body (3) is supported. A swivel structure comprising the above slide block (8).
The slide block (8) is divided into a plurality of groups (G1, G2) along the circumferential direction of the fixing ring (7), and the preload amount of the rolling element (80) of the slide block (8) is varied for each group. The swivel structure according to claim 1.
Of the plurality of groups (G1, G2, G3, G4) formed by the slide block (8), the group (G1) that gave the maximum amount of preload to the rolling elements (80) of the slide block (8) The swivel structure according to claim 2, characterized in that the group (G3) to which the minimum amount of preload is applied faces each other across the center of the fixing ring (7).
The swivel structure according to claim 2, wherein the plurality of slide blocks (8) are arranged at equal intervals along the circumferential direction of the fixing ring (7).
The swivel structure according to claim 2, wherein an arrangement interval of the slide blocks (7) in each group is set smaller than an interval between adjacent groups.
A gear ring (73) having a tooth row on the inner peripheral surface or the outer peripheral surface is disposed in the lower structure adjacent to the axial direction of the fixing ring (7) and meshes with the tooth row of the gear ring (73). The turning structure according to claim 1, wherein a pinion gear (10) and a motor (11) for rotationally driving the pinion gear (10) are provided in the upper turning body (3).