JP4533642B2 - Winding wheel bearing structure for windmill - Google Patents

Description

  The present invention relates to a slewing ring bearing structure for a windmill, and more particularly to a slewing ring bearing structure for a windmill that is double-rowed.

  In order to preserve the global environment, it is desired to use natural energy with a low environmental impact. Wind energy is promising as natural energy. A windmill generator is a rotating machine that converts wind energy into electric power. As shown in FIG. 17, the wind turbine generator includes a support tower, a wind turbine base 102 that is turnably supported by a turning shaft 101 that is a part of the support tower, and a blade that is rotatably supported by the windmill base 102. The vehicle body (rotor head) 103 is comprised. A plurality of blades (e.g., three blades) 104A, 104B, and 104C are supported by the rotor head 103 so as to be pivotable (variable in pitch) by the rotor head 103 via pivotal bearings 105A, 105B, and 105C, respectively. Yes. As shown in FIG. 18, the slewing ring bearing 105B is formed of an outer ring 106 on the non-swinging side (rotor head side) and an inner ring 107 on the slewing side (blade side). An annular rolling element row 108 is interposed between the outer ring 106 and the inner ring 107. The elements (rolling elements) of the rolling element row 108 are shaped as rolling balls having an approximately spherical surface or rolling rollers having an approximately cylindrical surface (a drum surface).

  The slewing ring bearing 105B supporting one of the three blades 104B shown in FIG. 17 has an external force Fxb directed to the axis XB, a rotational moment Mxb around the axis XB, an external force Fyb directed to the axis YB, and an axis YB. , The external force Fzb directed to the radiation ZB intersecting at right angles to the rotational axis of the rotor head 103, and the rotational moment Mzb around the radiation ZB. Such two-dimensional three-dimensional forces generate surface pressures on a large number of rolling elements of the outer ring 106, the inner ring 107, and the rolling element row 108. Such a surface pressure acts as a deformation force on the outer ring 106, the inner ring 107, and the rolling element row 108. Such deformation force is expressed as a distribution function of the circumferential position corresponding to the ball numbers of a large number of rolling elements arranged on the same circumference, and the ball load received by the rolling element or the surface pressure at that position is It is not constant but fluctuates greatly. Such a deformation force appears as a cause of improper friction generated in the slewing ring bearings 105-A, B, and C, and shortens the life of the slewing ring bearing.

  It is expected that such improper deformation is appropriately minimized by changing the single row slewing ring bearing to a double row slewing ring bearing (example: two rows). In a double row slewing ring bearing having a double row rolling element row, it is necessary that the load shared by the outer ring and the inner ring corresponding to the double row rolling element row be properly distributed (for example, load equal distribution). . The load equal distribution is realized by the high rigidity of the double-row slewing ring bearing or the equal total rigidity (bearing rigidity + support rigidity) corresponding to each rolling element array. If the total rigidity corresponding to each rolling element row is not equal, the surface pressure of the bearing portion of the row that supports more load increases, leading to early damage of the portion.

  It is required to change the single row slewing ring bearing to a double row slewing ring bearing (example: two rows). In that case, it is important that the double row does not cause improper load distribution.

JP-A-7-310654

An object of the present invention is to provide a slewing ring bearing structure for a windmill that simultaneously realizes double-row slewing ring bearings and equalization of surface pressure (equalization of ball load).
Another object of the present invention is to provide a slewing ring bearing structure for a windmill that realizes equalizing of the surface pressure by making the slewing ring bearings double-rowed and making the proper load distribution equal to the load.
Still another object of the present invention is to provide a slewing ring bearing structure for a windmill that doubles slewing ring bearings and realizes equalization of surface pressure in the case of uneven load distribution.

  A wind turbine slewing ring bearing structure according to the present invention includes a main body (1: rotor head) and a plurality of slewing ring bearings (3) supported by the main body (1) and slewably supporting a plurality of variable pitch blades. It is configured. The slewing ring bearing (3) includes an inner ring (5), an outer ring (4), a first rolling element row (6) interposed between the inner ring (5) and the outer ring (4), and an inner ring (5). And a second rolling element row (7) interposed between the outer ring (4) and the outer ring (4). The 1st rolling element row | line | column (6) and the 2nd rolling element row | line | column (7) are double-rowed along with the rotation axis direction mutually. The first load distribution received by the first rolling element row (6) is expressed as a first distribution function (FIG. 9) of the first rolling element number corresponding to the circumferential position of the first rolling element row (6). The second load distribution received by the second rolling element row (7) is expressed as a second distribution function (FIG. 10) of the second rolling element number corresponding to the circumferential position of the second rolling element row. The slewing ring bearing (3) has a load distribution structure that actively reduces the load difference distribution between the first load distribution and the second load distribution. It is free to add the third rolling element row.

  As a result, the load difference distribution between both rows is expressed as a function of the circumferential position. The load difference distribution is not constant and does not necessarily become zero in the entire circumference, but the size of the load difference distribution becomes smaller overall, the rolling element load is equalized, and as a result, the surface pressure difference distribution becomes flat. Is done. The load distribution structure can reduce the load difference distribution by flattening the entire circumference.

  The load distribution structure is effective by positively giving a difference in diameter between the ball diameter of the first rolling element in the first rolling element row (6) and the ball diameter of the second rolling element in the second rolling element row (7). To be realized. When the loads (f1, f2) received by the main body side of the outer ring (4) and the wing side of the outer ring (4) are not equal, a simple structure that gives a ball diameter difference corresponding to the load difference (f2-f1) The load distribution can be flattened.

  The load distribution structure positively affects the thickness difference between the first thickness of the outer ring (4) on the first rolling element row (6) side and the second thickness of the outer ring (4) on the second rolling element row (7) side. It can be effectively realized by giving it automatically. The rigidity difference distribution between the rigidity on the first rolling element row (6) side and the rigidity on the second rolling element row (7) side is flattened, the load is evenly distributed in both rows, the ball load distribution or the surface pressure The distribution is flattened.

  The load distribution structure is effectively realized by positively giving a length difference between the first length of the outer ring (4) in the turning axis direction and the second length of the inner ring (5) in the turning axis direction. The load is equally distributed in both rows, and the ball load distribution or the surface pressure distribution is flattened.

  The load distribution structure is effectively realized by positively giving a preload difference between the preload applied to the first rolling element row (6) and the preload applied to the second rolling element row (7). The surface pressure distribution is flattened in both rows.

  This is effectively realized by positively giving a difference in preload by positively giving a difference in diameter between the sphere diameter R1 of the first rolling element and the sphere diameter R2 of the second rolling element. The surface pressure distribution is flattened in both rows.

  The load distribution structure is equipped with a ring plate (13) joined to the side peripheral surface of the outer ring (4) or the side peripheral surface of the inner ring (5), and is effective by adding rigidity to the outer ring or inner ring to the ring plate (13). To be realized. The rigidity distribution of both rows is flattened, the load (f1, f2) for each row is evenly distributed, and the load difference distribution and the surface pressure difference distribution are flattened in both rows.

  In the load distribution structure, one of the rolling element rolling surface of the outer ring (4) and the rolling element rolling surface of the inner ring (5) or both the rolling element rolling surface of the outer ring and the rolling element rolling surface of the inner ring is non-circular. It is effectively realized by forming it. The rolling element load difference distribution in both rows is flattened.

  In the load distribution structure, a first retainer (not shown) for holding the first rolling element row is formed in a single ring, and a second retainer (not shown) for holding the second rolling element row is formed in a single ring. By forming the first retainer and the second retainer as a single ring of the same body, a single rigid body is formed between the outer ring and the inner ring, and the rolling element load difference distribution in both rows can be flattened. Promoted. Such a multiple single ring structure makes it possible to make the phases of the rolling elements in both rows the same with higher accuracy, further promoting the averaging of the rolling element load distribution in both rows.

  The load distribution structure is easily realized by configuring the slewing ring bearing (3) as a two-row spherical rolling bearing. A two-row spherical rolling bearing, which is well known and is already on the market in the machine parts market, is remarkably effectively used for realizing the present invention, and can easily flatten the ball load difference distribution.

  The slewing ring bearing structure for wind turbines according to the present invention can flatten the surface pressure difference distribution by flattening the load difference distribution, and can simultaneously realize double row and uniform surface pressure of the slewing ring bearing.

  The realization of the slewing ring bearing structure for wind turbines according to the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the impeller body (rotor head) 1 includes a wind power take-off rotary shaft 2 and three sets of swirl ring bearings 3. Three variable pitch blades (not shown) are respectively supported by the three sets of slewing ring bearings 3. The respective turning axis lines of the three sets of turning ring bearings 3 are arranged at equal angular intervals of 120 degrees on the same plane.

  FIG. 2 shows a region on the outer peripheral side of the pair of slewing ring bearings 3 in an oblique axis projected cross section. The slewing ring bearing 3 is formed of an outer ring 4 fixed to the rotor head 1 side and an inner ring 5 fixed to the blade side. A first rolling element row 6 and a second rolling element row 7 are interposed between the inner peripheral surface of the outer ring 4 and the outer peripheral surface of the inner ring 5. The respective elements of the first rolling element row 6 and the second rolling element row 7 are formed as rolling elements such as balls and rollers. The 1st rolling element row | line | column 6 and the 2nd rolling element row | line | column 7 are spaced apart by the appropriate space | interval D in the turning axis direction of the turning axis line L. FIG.

  The results of FEM analysis of the surface pressure generated on the surfaces of the outer ring 4 and the inner ring 5 are drawn on the surfaces. The retainers (retainers) for holding the rolling elements of the two first rolling element rows 6 and the second rolling element row 7 are formed as a single body or as an integral body. Various known double row rolling bearings are used as the first rolling element row 6 and the second rolling element row 7. As the double row rolling bearing, a double row spherical (ball) bearing, a double row spherical roller bearing (self-aligning roller bearing) can be used.

  FIG. 3 shows two regions in which the load f1 and the load f2 are distributed in the direction of the swivel axis with the load even or uneven, and the surface pressure is equalized in the circumferential direction (the surface pressure difference distribution is flattened). Yes. The circumferential direction coordinates are discretized by the ball numbers of balls that are a plurality of rolling elements arranged on the same circumference. The outer ring 4 of the integral object corresponds to the first turning axis direction outer ring portion 8 that corresponds in position to the first rolling element row 6 in the turning axis direction, and to the second rolling element row 7 in position corresponding to the turning axis direction. The region is virtually divided into the second turning axis direction outer ring portion 9. The inner ring 5 of the integral object corresponds to the first turning axis direction inner ring portion 11 that corresponds in position to the first rolling element row 6 in the turning axis direction and to the second rolling element row 7 in position corresponding to the turning axis direction. The region is virtually divided into a second turning axis direction inner ring portion 12. The first turning axis direction outer ring portion 8 and the second turning axis direction outer ring portion 9 are divided into two in the turning axis direction by a virtual center plane S orthogonal to the turning axis L. The first turning axis direction inner ring portion 11 and the second turning axis direction inner ring portion 12 are bisected by the virtual center plane S in the turning axis direction.

  FIG. 4 shows a realization of load distribution in the wind turbine slewing ring bearing structure according to the present invention. If the load f1 acting on the outer peripheral surface of the first turning axis direction outer ring portion 8 is smaller than the load f2 acting on the outer peripheral surface of the second turning axis direction outer ring portion 9, the balls of the first rolling element row 6 The ball diameter is smaller than the ball diameter of the balls in the second rolling element row 7. Since the load capacity of the ball is larger as the ball diameter is larger, the magnitude relationship between the load and the ball diameter equalizes the degree of deformation or the internal stress distribution of the first turning axis direction outer ring portion 8 and the second turning axis direction outer ring portion 9. (Flatten). A part of the load f2 larger than the load f1 is distributed and supported by the first rolling element row 6. In this realization state, the surface pressure distribution is flattened regardless of the uneven load distribution.

  FIG. 5 shows another embodiment of load distribution of the wind turbine slewing ring bearing structure according to the present invention. When the load f2 acting on the outer circumferential surface of the second turning axis direction outer ring portion 9 is larger than the load f1 acting on the outer circumferential surface of the first turning axis direction outer ring portion 8, the first turning axis direction outer ring portion 8 The radial thickness is made thicker than the radial thickness of the second turning axis direction outer ring portion 9. The diameters of the first rolling element row 6 and the second rolling element row 7 are the same. The rigidity of the first turning axis direction outer ring part 8 is larger than the rigidity of the second turning axis direction outer ring part 9, and as a result, a larger load is applied to the larger rigidity, f2 becomes smaller and f1 becomes larger. Therefore, the equal distribution of the loads of the first rolling element row 6 and the second rolling element row 7 is realized. The surface pressure (surface pressure difference distribution) of the bearing is equalized by the load distribution. Such a magnitude relationship between the first turning axis direction outer ring portion 8 and the second turning axis direction outer ring portion 9 is correct as a general tendency, but in reality, the thickness and shape of the actual product based on the result of FEM analysis The position of the virtual center plane S in the direction of the pivot axis is determined. In this embodiment, the load distribution can be realized as an even distribution.

  FIG. 6 shows still another realization of the load distribution of the wind turbine slewing ring bearing structure according to the present invention. This mode of realization is the same as the embodiment of FIG. 5 in that the shapes of the outer ring 4 and the inner ring 5 are adjusted. Corresponding to the magnitude relation between f1 and f2, the magnitude relation of the width of the outer ring 4 and the inner ring 5 in the direction of the turning axis is determined. Alternatively, corresponding to the magnitude relationship between f1 and f2, the magnitude relation of the width in the turning axis direction of the first turning axis direction outer ring portion 8 and the second turning axis direction outer ring portion 9, or the first turning axis direction inner ring portion 11 And the width relationship of the second turning axis direction inner ring portion 12 in the turning axis direction is determined. In this embodiment, the load distribution can be realized as an even distribution.

FIG. 7 shows still another realization of the load distribution of the wind turbine slewing ring bearing structure according to the present invention. Corresponding to the magnitude relationship between f1 and f2, a slight difference ΔR is given to the ball diameter R1 of the first rolling element row 6 and the ball diameter R2 of the second rolling element row 7.
ΔR = R2-R1 = K · (f2-f1)
K: The first rolling element row 6 and the second rolling element row 7 are sandwiched between the minute value outer ring 4 and the inner ring 5, and the first rolling element row 6 and the second rolling element row 7 are strongly clamped between the outer ring 4 and the inner ring 5. Thus, when the first rolling element row 6 and the second rolling element row 7 are sandwiched, the load f1 acting on the outer circumferential surface of the first turning axis direction outer ring portion 8 is the outer circumferential surface of the second turning axis direction outer ring portion 9. When the load f2 is larger than the load f2, the ball 7 having a slightly larger ball diameter has a higher preload and thus has a higher rigidity. As a result, a larger load is applied to the larger rigidity. , F1 is reduced and f2 is increased, so that the load distribution between the first rolling element row 6 and the second rolling element row 7 is equalized. In this realization state, it is possible to achieve equalization of the bearing surface pressure (flattening of the surface pressure difference distribution) by adjusting the preload. By providing a slight difference between the diameter R1 ′ of the annular row of the first rolling element row 6 and the diameter R2 ′ of the annular row of the second rolling element row 7 in accordance with the idea of preload adjustment in this realization state, Can be equalized (flattened) between the two rows.

  FIG. 8 shows still another realization of load equalization. A ring plate 13 having a thickness corresponding to the magnitude relationship between f1 and f2 is attached to the side peripheral surface of the first turning axis direction outer ring portion 8, and a ring plate 13 having a thickness corresponding to the magnitude relationship between f1 and f2 is the second turning shaft. A ring plate 13 ′ having a thickness corresponding to the magnitude relationship between f1 and f2 is attached to the side circumferential surface of the first turning axis direction inner ring portion 11, or between f1 and f2. A ring plate 13 ′ having a thickness corresponding to the magnitude relationship is attached to the side peripheral surface of the second turning axis direction inner ring portion 12. Alternatively, the thickness of the ring plate 13 attached to the first turning axis direction outer ring portion 8 and the thickness of the ring plate 13 ′ attached to the first turning axis direction inner ring portion 11 are adjusted in accordance with the magnitude relationship between f1 and f2. The Alternatively, the thickness of the ring plate 13 attached to the second turning axis direction outer ring portion 9 and the thickness of the ring plate 13 'attached to the second turning axis direction inner ring portion 12 are adjusted in accordance with the magnitude relationship between f1 and f2. The The load distribution can be realized as an even distribution by adjusting the rigidity.

  9 to 12 show the FEM analysis results of the load distributed by the load distribution described above (horizontal axis: angular coordinates relating to one round of the inner and outer rings, which are discretized by ball numbers). . FIG. 9 shows the ball load on the rotor head side among the results of FEM analysis performed by changing the distribution ratios of f1 and f2. F1 in FIG. 9 indicates the ball load distribution on the rotor head side. FIG. 10 shows the load distribution weight on the wing side based on the distribution ratio. The ball load on the rotor head side is larger than the ball load on the wing side. The ball load distribution when a normal load with a distribution rate of 50% is applied is smaller on the rotor head side in the entire circumference than the ball load distribution when a normal load with a distribution rate of 59% or a distribution rate of 61% is applied. It is suppressed. FIG. 11 shows the surface pressure on the rotor head side corresponding to the ball load of FIG. FIG. 12 shows the surface pressure corresponding to the ball load distribution of FIG. The surface pressure distribution when a normal load with a distribution rate of 50% is applied is smaller on the rotor head side in the entire circumference than the surface pressure distribution when a normal load with a distribution rate of 59% or a distribution rate of 61% is applied. It is suppressed. Thus, those values are suppressed small on the side where the ball load distribution and the surface pressure distribution are large, and they are large on the small side, and both distributions are flattened. 9 to 12 show that the ball load difference distribution and the surface pressure difference distribution in both rows are flattened, and that the equal distribution is an appropriate distribution.

  FIGS. 13 to 16 show FEM analysis results of loads corresponding to load distribution by adding the ring plate (one top plate) of FIG. When the distribution ratio is 48%, which is close to 50%, the ball load difference distribution and the surface pressure difference distribution are generally further flattened on the rotor head side where the ball load and the surface pressure are large. ing.

Other examples:
As still another embodiment of uneven load distribution, by using a two-row spherical roller bearing, adjusting the preload on the roller increases the load capacity of the bearing and can absorb some load unevenness. The integration of the cage of the first rolling element row 6 and the cage of the second rolling element row 7 is effective for equalizing (flattening) the surface pressure. It is effective to equalize the ball load on one circle. In order to equalize the ball load, both the rolling surface of the outer ring 4 and the rolling surface of the inner ring 5 are formed in a non-round shape, or one of the outer ring 4 and the inner ring 5 is formed in a non-round shape. By adjusting the preload to be applied, the surface pressure distribution of the bearing can be equalized (flattened).

FIG. 1 is an oblique projection showing a slewing ring bearing structure showing an application target of the present invention. FIG. 2 is a cross sectional view of the oblique axis projection of a part of FIG. FIG. 3 is a cross-sectional view showing a region division of the slewing ring bearing. FIG. 4 is a cross-sectional view showing a realization of the wind turbine slewing ring bearing structure according to the present invention. FIG. 5 is a cross-sectional view showing another embodiment of the wind turbine slewing ring bearing structure according to the present invention. FIG. 6 is a sectional view showing still another embodiment of the wind turbine slewing ring bearing structure according to the present invention. FIG. 7 is a sectional view showing still another embodiment of the wind turbine slewing ring bearing structure according to the present invention. FIG. 8 is a sectional view showing still another embodiment of the wind turbine slewing ring bearing structure according to the present invention. FIG. 9 is a graph showing the ball load distribution of the wind turbine slewing ring bearing structure according to the present invention. FIG. 10 is a graph showing another ball load distribution of the slewing ring bearing structure for wind turbines according to the present invention. FIG. FIG. 11 is a graph showing the surface pressure distribution of the slewing ring bearing structure for a wind turbine according to the present invention. FIG. 12 is a graph showing another surface pressure distribution of the slewing ring bearing structure for wind turbines according to the present invention. FIG. 13 is a graph showing still another ball load distribution of the wind turbine slewing ring bearing structure according to the present invention. FIG. 14 is a graph showing still another ball load distribution of the wind turbine slewing ring bearing structure according to the present invention. FIG. FIG. 15 is a graph showing still another surface pressure distribution of the slewing ring bearing structure for wind turbines according to the present invention. FIG. 16 is a graph showing still another surface pressure distribution of the slewing ring bearing structure for wind turbines according to the present invention. FIG. 17 is an oblique projection showing a known slewing ring bearing structure. FIG. 18 is an oblique projection showing a known slewing ring bearing.

Explanation of symbols

1 ... Main body (rotor head)
3 ... slewing ring bearing 4 ... outer ring 5 ... inner ring 6 ... first rolling element row 7 ... second rolling element row 13 ... wheel plate

Claims (3)

The body,
A plurality of slewing ring bearings that are supported by the main body and pivotally support each of the plurality of variable pitch blades;
The slewing ring bearing is
Inner ring,
Outer ring,
A first rolling element row interposed between the inner ring and the outer ring;
A second rolling element row interposed between the inner ring and the outer ring,
The first rolling element row and the second rolling element row are aligned with each other in the turning axis direction,
The first load distribution received by the first rolling element row is expressed as a first distribution function of the first rolling element number corresponding to the circumferential position of the first rolling element row, and is received by the second rolling element row. The second load distribution is expressed as a second distribution function of the second rolling element number corresponding to the circumferential position of the second rolling element row,
The slewing ring bearing has a load distribution structure that actively reduces a load difference between the first load distribution and the second load distribution,
The load distribution structure includes a ring plate joined to a side peripheral surface of the outer ring or a side peripheral surface of the inner ring,
The wheel plate is a slewing ring bearing structure for windmills, which adds different rigidity to the outer ring or the inner ring on the first rolling element row side and the second rolling element row side . In the load distribution structure, the first retainer that holds the first rolling element row is formed in a single ring, and the second retainer that holds the second rolling element row is formed in a single ring, and the first retainer The slewing ring bearing structure for a wind turbine according to claim 1, wherein the first retainer and the second retainer are formed as a single ring. The wind turbine slewing ring bearing structure according to claim 1 , wherein the load distribution structure configures the slewing ring bearing as a rolling bearing of a two-row spherical roller.

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