DE10318945B3 - Planetary gearing, for a wind energy generator, has a bearing structure where the load from the external rotor is minimized on the bearings and gear components to increase their life - Google Patents

Abstract

The planetary gearing for a wind energy generator has a rotating hollow planet wheel (16) within the gear housing (14), keyed to the generator drive unit (10). The planet wheels (18) are with tumble bearing mountings with elastomer bushes on at least one planet bolt (22), fitted to a planet carrier plate (24). The gearing includes a sun wheel (32). The leading gear bearing (12) of the hollow planet wheel is on the plane of the gear teeth of the first gear stage. The planet carrier plate is bonded to the gear housing.

Description

The The invention relates to a gear arrangement for a wind energy installation (wind turbine), with a rotating, mounted planet ring gear, in a fixed Satellite carrier plate attached planet bolts, planet gears and a sun gear due to the special requirements regarding the meshing quality the great external forces and Moments.

The Development of wind turbines in recent decades has led to steadily increasing performances, whereby the trend towards ever more compact and lighter units continued. This trend has meant that the components installed in the wind turbine are increasingly deformed also in load-transferring Exposed to parts. These larger deformations, in particular under dynamic loads especially in the case of bearings and gear parts that are locally too impermissibly strong local voltage spikes. And these in turn have a significant reduction in the lifespan of the components. With bearings and gear wheels can already an offset in the toothing or a raceway deviation of the rolling elements of 10 up to 25 μm due to tilting due to external forces and Moments to such a large overload to lead, that the components fail after a very short time and thus to significant financial damage to lead. Furthermore, it has been shown in recent years that a targeted Lubrication of the meshes and the bearings is necessary to the desired To achieve lifespan. Gearbox and bearing damage have occurred in recent years some wind turbine manufacturers led to the brink of bankruptcy. Also Wind turbine operators and insurers are financially responsible for the damage affected.

Just with the increasing size of the wind turbines it is necessary to take effective remedial measures against the inevitable Deformations while the machine set is compact to realize. In the past, there have been different ones proposals been made.

By WO 02/14690 A1 proposes a rotor bearing in which the inner ring firmly over the gear ring gear with the machine frame and the outer ring is connected to the rotor hub and the planet carrier. This arrangement has the disadvantage that the planet carrier and thus the planet gears rotate and therefore insufficiently lubricated gears and planet bearings can be because the oil transfer on the rotating part is complex and prone to failure. Furthermore, the external loads on the Ring gear on the machine frame derived what is deformed by it and thus a negative Influence on the meshing quality between ring gear and planet gear.

The WO 02/79644 A1 suggests double planet gears before, which are mounted on a flexible disc, thereby uneven meshing conditions to be able to dodge. Even with this solution are the above Disadvantages are given, the construction effort is still significant elevated is.

With the EP 1184567 A2 a solution is proposed in which a stepped planetary gear is used and the rotor is mounted directly in the gear housing. The bearing should be designed as a plain bearing. The result of this geometric arrangement is that the rotor forces lead to shifts in the toothing, which have an adverse effect on the service life. Furthermore, the design requires a large number of components, some of which have to be positioned extremely precisely in relation to one another in order to achieve an acceptable load distribution factor for the torque components of the individual planet gears. This makes the construction complex, heavy and expensive.

In WO 96/11338 A1 is also the rotor bearing on the planetary carriers of the transmission proposed. This also affects here from the external rotor loads resulting deformations negatively affect the gear engagement. A compensatory measure is not provided, so with premature wear of the gears due to local overload to calculate.

in the During the Hanover Fair in April 2003, a technical paper was: G. P. Fox and E. Jallat, "Use of the integrated Flexpin bearing for improving the performance of epicyclical gear systems ". It proposes a two-stage planetary gear, the is very compact, but has the disadvantage that Geometric arrangement of the two planetary stages for drive mounting a strong influence of external stress on the meshing quality is present. The proposed use of so-called IFB (Integrated Flexpin Bearing) provides a remedy for the equalization of the Loads from torque transmission over 5 or 7 planet gears, but only insufficient compensation for the existing deformations from rotor loads.

All these suggestions do not provide a complete remedy for the above Problems.

The limits of the manufacturing feasibility for large bearings and gear teeth for wind turbines have been reached with the 4-5 MW class in a conventional design. Rotor bearings and ring gears of planetary gears with approx. 3 m outside Diameters and widths of approx. 500 mm currently represent the maximum producibility. With these dimensions, the maximum torque of an approx. 5 MW system can be transmitted when using three planetary gears. The large tooth width leads to problems of uniform engagement of the toothing over the entire width of the teeth when external loads act on these components. This means that the planet gears can avoid the deformation that is forced on them, especially the tilting around the axes perpendicular to the axis of rotation of the planet gears, in order to allow the tooth meshes to take place optimally in all load situations, ie evenly across the tooth width.

Further exists with conventional Planet-driven the problem that the planet gears rotate and thus a controlled supply to the planetary bearings and the Gearing with the lubricant is difficult.

task the invention is, given the desired compactness of the drive train unit, consisting of rotor bearing and gear, the negative effect of the external rotor loads on the bearings and gear components to minimize the to achieve the intended service life.

According to the invention Task solved by that the front gearbox bearing of the planetary ring gear is in one level or almost in one level with the central level of the gear teeth is arranged, the planet carrier plate firmly with the gearbox is connected and the planet gears on the one with the planet carrier plate firmly connected planet bolts are swash-bearing. The planetary gears Make limited twists perpendicular to their axis of rotation.

The front gearbox bearing that loads and shear loads if necessary, the axial forces and makes bending moments in the gear housing, is arranged that the outer ring of the bearing with the housing is fixedly connected and the inner ring of the bearing in one plane, preferably centered on the toothing directly or indirectly with the ring gear of the first Gear stage is connected. The ring gear is thus directly through the hub or drive shaft is driven by the rotor of the wind turbine. By This geometrical arrangement mainly affects the bending moments of the rotor so that there is only a slight tilting of the Ring gear leads transversely to the axis of rotation without causing major radial displacements comes in the area of the meshes. This is the prerequisite created that only a slight angle compensation of the planetary gear setting must take place in order to optimally mesh the teeth under all load situations to take place. The planetary gears of the first stage are over one Pivot bearing in connection with a wobble bearing element on the Planet bolts attached, these in turn fixed in a planet carrier plate are attached, which in turn is connected to the housing. Purpose of Swash bearing element is the planet gear when tilting the ring gear to enable a movement in the same direction. The necessary for that Moment on the swash bearing element arises from the non-constant Line load on the tooth mesh while wearing the edge. So the planetary gear can deviate in the event of angular deviations between the axes position neatly to the ring gear and provide a relatively even line load on. The sun in turn adapts to the planet wheels and ensures so also constant wearing. With the help of such a wobble bearing element can do the harmful Edge wear of the gearing can be avoided more effectively. The pivot bearing the planet gears can by rolling bearings or plain bearings can be realized. To the required tumbling turning ability the planet gears to achieve is z. B. a spherical Plain bearing or the use of an elastomer bushing in Connection with a separate pivot bearing advantageous. The spherical plain bearing stands out due to the large sliding surface due to high radial rigidity and due to the unobstructed turning ability due to low restoring moments with wobble movements. The use of elastomer bushings with separate pivot bearings are characterized by a slight radial absorbing capacity off, resulting in the use of a variety of planet gears effective compensation of manufacturing tolerances of the components takes place and it evens out the Load distribution comes under the multitude of planet gears. Both positions enable tilting the planet gears transverse to their axis of rotation, causing them to deform of the ring gear can be adjusted easily without major component stress in the components or uneven flanking of the tooth mesh with the disadvantages described. Through the fixed standing planet bolts can be done in a simple and reliable manner the planet gearing and the planetary bearing with the required Lubricant can be supplied without complex rotary introduction into rotating Need to use parts. This creates a construction that provides optimal load balancing creates minimal structural stress and precise lubrication the planetary bearings and meshes and thus a high Operational safety and long life guaranteed.

In most of the applications of planetary gears, three planet gears are used, as this simply means an even load distribution division can be ensured. However, if it is possible to constructively accommodate a larger number of planet gears in such a way that there is a good load distribution, significantly higher torques and powers can be transmitted for a given ring gear diameter and tooth width. Or the tooth width can be reduced for a given torque and ring gear diameter, which leads to a reduction in the problems with an exact tooth engagement under external loads.

adversely when using a larger number of planet gears is the decrease in the possible gear ratio. So if a higher translation a second stage is required, a further stage is advisable Planetary stage behind it. Here, for. B. the sun gear the first stage connected to the ring gear of the second stage. Thereby then also has the second stage of fixed planet gears, the can be lubricated easily and effectively.

If the front gearbox bearing is designed as a torque bearing, that is able to handle the rotor forces to transmit and moments alone, builds the complete rotor bearing and gear unit very compact, easy and inexpensive. The gearbox then becomes the machine housing of the complete wind turbine at the same time which can then also be used to add all other components.

The In the following, the invention is based on an exemplary embodiment of the invention reproducing drawing explained. It shows:

1 a single-stage planetary gear,

2 a two-stage planetary gear,

3 an example of a wobbling pivot element,

4 another example of a wobbling pivot member and

5 the complete nacelle of a nacelle provided with such a gear.

1 shows a first planetary gear stage with the drive element 10 , which can be the drive shaft or the rotor hub of the wind turbine, the front gearbox bearing 12 , whose fixed outer ring with the gear housing 14 and its rotating inner ring with the planet ring gear 16 connected is. The gearbox bearing 12 lies in the middle level 13 the planet gearing 18 , The planet gears 18 are about tumbling pivot bearing elements 20 on the respective planet bolts 22 attached. The planet bolts 22 are in a planet carrier plate 24 attached, which in turn to the gearbox 14 are firmly connected. A front seal 26 , the sealing plate 28 and the rear seal 30 close off the oil-laden gear chamber from the outside. The sun gear 32 transfers the drive power to the following elements of the drive train.

2 shows a two-stage version of the planetary gear. The same elements are present in the first stage as in the 1 , In addition, the sun gear is the first stage 32 via a connecting flange 34 with the ring gear of a second stage 36 connected, this assembly via a fixation bearing 38 and the planet carrier plate 24 in the gearbox 14 is stored. The ring gear of the second stage 36 drives the planet gears 40 , which in turn has tumbling rotating elements 42 on the planet bolt 44 are stored. The planet bolts 44 are in a planet carrier plate 46 attached, which in turn to the gearbox 14 connected is. Via a single or double gimbal sun gear suspension 48 the drive power is transferred to the following elements such as a generator or another gearbox. The rear seal 30 closes off the oil-loaded gearbox.

3 shows the detail of an embodiment of a tumbling pivot bearing element with an elastomer bushing 50 that with their inside on the planet bolt 44 is arranged and on its outside the pivot bearing 52 wearing. The arrangement of the elastomer enables the planet gear 18 the desired wobbling movement with relatively low restoring forces and high radial rigidity at the same time. The pivot bearing 52 establishes the connection to the planet gear 18 with the external toothing 54 forth and can be designed as roller or plain bearings. The arrangement of the elastomer bushing 50 and swivel 52 can also be done in a radially reverse manner. Via the oil feed hole 56 the lubricant is through the supply holes 58a . 58b in the pivot bearing 52 and the gearing 54 guided.

4 shows the detail of an alternative embodiment of the tumbling pivot bearing element, which is a spherical plain bearing 60 with inner ball element 62 and outer element 64 is executed. On the outer element 64 is the planet gear 18 with the gearing 54 arranged. The oil supply hole 56 supplied via the supply boreholes 58 the spherical plain bearing 60 and the gearing 54 with the necessary lubricant.

5 shows a complete wind turbine nacelle with the gear arrangement according to the invention, the front gear bearing 12 as a moment bearing is carried out that all rotor loads take over from forces and moments and on the machine frame 14 can transmit. A separate gear housing can be omitted. The drive element 10 in this case is the rotor hub of the wind turbine directly with the planetary ring gear 16 connected is. The ring gear 16 is with the inner ring 66 of the torque bearing and the outer ring 68 with the machine carrier 14 , The front seal 26 , the sealing plate 28 and the rear seal 30 close off the oil-laden gear chamber from the outside. The generator is on the opposite side of the rotor 70 in the machine frame 14 integrated. This creates a very compact and light unit. The generator 70 consists of the fixed stator 72 that over the generator housing 86 with the machine carrier 14 is firmly connected. The rotor 74 of the generator 70 is via a coupling element 76 with the generator shaft 78 connected, in turn, through storage 80 is stored. The connection between the transmission output shaft 82 and the generator shaft 78 is through a connecting shaft 84 manufactured.

Claims (10)

Planetary gear for a wind turbine (wind turbine), with a gear housing ( 14 ), one in the gearbox ( 14 ) mounted, rotating planetary ring gear ( 16 ) that is fixed to the drive element ( 10 ) the wind turbine is connected and connected to at least one in a planet carrier plate ( 24 ) attached planet bolts ( 22 ) mounted planet gears ( 18 ) and a sun gear ( 32 ), characterized in that the front gearbox mounting ( 12 ) of the planet ring gear ( 16 ) is arranged in the plane of the gear teeth of the first gear stage, the planet carrier plate ( 24 ) firmly with the gear housing ( 14 ) is connected and the planet gears ( 18 ) with the planet carrier plate ( 24 ) firmly connected planet bolts ( 22 ) are staggered. Planetary gear according to claim 1, characterized in that the front gear mounting ( 12 ) of the planet ring gear ( 16 ) is arranged in the central plane of the gear teeth of the first gear stage. Planetary gear according to claim 1 or 2 , characterized in that the drive element ( 10 ) is the rotor hub of the wind turbine. Planetary gear according to one of the preceding claims, characterized in that the gear housing ( 14 ) is the machine carrier for the whole wind turbine. Planetary gear according to one of the preceding claims, characterized in that the front gear bearing ( 12 ) is a moment bearing. Planetary gear according to one of the preceding claims, characterized in that the planet gears ( 18 ) via elastomer bushings ( 50 ) on the planet bolts ( 22 ) are staggered. Planetary gear according to one of claims 1 to 5, characterized in that the planet gears ( 18 ) via a spherical plain bearing ( 60 ) on the planet bolts ( 22 ) are staggered. Planetary gear according to one of the preceding claims, characterized in that the planet bolts with lubricant supply bores ( 56 . 58 ) are provided. Planetary gear according to one of the preceding claims, characterized by a second planetary gear stage, the sun gear ( 32 ) the first stage via a connecting flange ( 34 ) with the ring gear ( 36 ) is connected to the second stage, the planet gears ( 40 ) of the second stage are stationary and the second sun gear ( 48 ) drives the slowly rotating generator of the wind turbine. Planetary gear according to one of the preceding claims, characterized characterized that the number of planet gears is> 3.