Gear arrangement and wind turbine

Abstract

The invention relates to a gearbox arrangement for a wind turbine (10) comprising a gearbox (22) and a rotor shaft arrangement. The gearbox (22) has a gearbox housing (36) and a gear set arranged in an interior space of the gearbox housing (36). A rotating element (38) of the gear set forms a drive for the gearbox (22). The rotating element (38) is permanently and rotationally fixed to a rotor shaft (16) of the rotor shaft arrangement. The gearbox housing (36) and a rotor shaft housing (70) are fixed to one another. The gearbox arrangement includes a sealing element (72). The sealing element (72) is designed to seal the gearbox housing (36) against the ingress of foreign substances from the rotor shaft housing (70). Furthermore, the sealing element (72) is designed to compensate for any positional deviation of the rotating element (38) relative to the gearbox housing (36) during sealing. The invention also relates to a wind turbine (10).

Description

[0001] The present invention relates to a gearbox arrangement for a wind turbine. Furthermore, the invention relates to a wind turbine. State of the art

[0002] Wind turbines are used to generate electricity from wind energy. For this purpose, wind turbines have a rotor. The rotor's rotational speed is transmitted by a rotor shaft to a gearbox. The gearbox then converts the rotor shaft's rotational speed into a suitable rotational speed to drive a generator. Parts of the gearbox are mounted on the rotor shaft because this is where the highest loads can occur during operation, and the rotor shaft bearings are therefore correspondingly robust. However, this also means that such parts can tilt or shift during operation, for example, due to bending of the rotor shaft. Consequently, sealing a gearbox housing can be difficult and costly. Furthermore, the ingress of foreign substances, such as dirt and water, into the gearbox housing can reduce the lifespan and efficiency of the wind turbine. Description of the invention

[0003] One aspect concerns the gearbox arrangement for a wind turbine. The wind turbine can, for example, have a rotor and a generator. The rotor can drive the generator via the gearbox to produce electrical energy. The rotor is connected to the gearbox, for example, via a rotor shaft. The rotor, gearbox, and generator can be attached to a nacelle of the wind turbine. The nacelle can be mounted on a tower, either fixed or rotatable. The rotor can have a horizontal or a vertical axis of rotation. The rotor can have, for example, two, three, four, or more rotor blades, which are connected to the rotor shaft via a hub.

[0004] The gearbox assembly comprises a gearbox and a rotor shaft assembly. The gearbox has at least one gearbox housing. The gearbox housing may, for example, have one or more housing elements. The gearbox housing may have an interior space. The gearbox housing may be mounted in the nacelle of the wind turbine. The gearbox may have an input and an output. The input is, for example, mechanically connected to the rotor, and the output to the generator. The gearbox housing has an interior space.

[0005] The gearbox has a gear set arranged inside the gearbox housing. A gear set can, for example, have several rotating elements. The gear set can, for example, have one or more spur gears. The gear set can be designed as a planetary gear set. A planetary gear set can, for example, have a sun gear, a planet carrier, and a ring gear as rotating elements. The gear set provides a transmission ratio. A rotating element of the gear set forms the drive of the gearbox. For example, the rotating element can form a shaft section that protrudes from the gearbox housing on the rotor side. The gearbox housing can have a through-opening on a side facing the rotor in the wind turbine, through which foreign matter can enter the gearbox.Through the through-opening, a shaft section, such as a section of the rotor shaft, can also protrude into the gearbox housing and thus be connected to the rotating element that forms the drive.

[0006] The rotating element that forms the drive of the gearbox can constitute an input shaft of the gearbox. The rotating element that forms the drive of the gearbox can be a single piece or multiple pieces. For example, the rotating element that forms the drive of the gearbox can have a shaft element and a gear that are permanently and rotationally fixed together. For example, the rotating element that forms the drive of the gearbox has an axial shaft section at its end facing the rotor in the assembled state.

[0007] Another rotating element, such as a ring gear, sun gear, or spur gear, can, for example, form the output of the gearbox. The gearbox can also have several planetary gear sets that are mechanically interconnected. For example, the output can also be formed by a rotating element of a second planetary gear set. Planetary gear sets can provide high gear ratios in a space-saving manner and withstand high torques well.

[0008] The rotating element, which drives the gearbox, is permanently and rotationally fixed to a rotor shaft of the rotor shaft assembly. For example, the planet carrier and the rotor shaft can have corresponding gear teeth through which the rotating element and the rotor shaft engage. However, such a gear toothing can allow a certain degree of relative movement of the rotating element to the rotor shaft. This can cause the rotating element to tilt slightly or be positioned slightly eccentrically. The rotor shaft and the planet carrier can otherwise be arranged essentially coaxially. Alternatively or additionally, the rotor shaft and the planet carrier can also be bolted together.

[0009] The rotor shaft assembly includes a rotor shaft housing. The rotor shaft can be at least partially located within the rotor shaft housing. The rotor shaft can be supported in the rotor shaft housing, for example, by rolling bearings or plain bearings. High loads can act on the rotor shaft due to the rotor, which is why a bearing arrangement close to the rotor allows for smaller bearings. For example, the rotor shaft is supported in the nacelle by two rolling bearings. The rotor shaft housing can be formed by the nacelle or be a separate housing located within the nacelle. The rotor shaft housing can, for example, have one or more housing elements. The rotor shaft housing can form an interior space. The rotor shaft housing can be mounted in the nacelle of the wind turbine.

[0010] The gearbox housing and the rotor shaft housing are fixed together. The rotor shaft housing allows the gearbox housing to be sealed on the rotor side. However, this also means that foreign substances, such as liquids and dirt, can pass from the interior of the rotor shaft housing into the interior of the gearbox housing and vice versa.

[0011] Therefore, the gearbox assembly incorporates a sealing element. This sealing element is designed to seal the gearbox housing against the ingress of foreign substances from the rotor shaft housing. Foreign substances can include liquids such as water, foreign bodies such as sand or stones, and contaminants such as dust. These foreign substances may be materials whose presence in the interior of the gearbox housing is not intended. Conversely, other materials whose presence is intended, such as lubricating oil for the gear set, cannot be considered foreign substances. The sealing element is made, for example, of an elastic material such as rubber. The sealing element separates, for example, the interior of the gearbox housing from the interior of the rotor shaft housing, optionally together with the rotating element that drives the gearbox.

[0012] The sealing element is designed to seal the gearbox housing against the ingress of foreign substances from the rotor shaft housing. This can extend the gearbox's service life and reduce or eliminate the need for cleaning. The interior of the gearbox housing can be limited, for example, by the gearbox housing itself radially. Additionally, in the direction of the rotor, the interior can be limited axially and, alternatively or furthermore, radially internally by the rotating element that forms the drive, as seen from the rotor. The sealing element can, for example, seal between the rotating element that forms the drive and the gearbox housing.

[0013] The sealing element is further designed to compensate for positional deviations of the rotating element relative to the gearbox housing during sealing. This allows the rotating element, which forms the drive, to be supported, for example, only on the rotor shaft without compromising the sealing effect. The sealing element can compensate for positional deviations, for instance, through elastic deformation. This compensation can occur without damaging the sealing element and without a significant loss of sealing effectiveness. The positional deviation can change during operation, for example, due to wind loads and the resulting deformations. The sealing element can also be designed to compensate for these changing positional deviations.

[0014] The positional deviation can exhibit eccentricity. For example, the rotating element that drives the gearbox may be slightly offset from the rotor shaft and, alternatively or additionally, from the gearbox housing. Alternatively or additionally, the positional deviation may also involve an angular deviation. For instance, the rotor shaft may extend slightly perpendicular to the rotating element and its axis of rotation. This can be caused by external loads as well as tolerances in manufacturing and assembly. Furthermore, the permanently rotationally fixed connection between the rotor shaft and the rotating element may have some play. This can result in a gap of varying width around the circumference, which the sealing element can then further seal.

[0015] In one embodiment of the gearbox arrangement, the sealing element can be designed to seal the gearbox housing against the ingress of foreign matter from the rotor shaft housing through a gap between the rotating element that drives the gearbox and the rotor shaft housing. The sealing element can, for example, seal a rotor-side inlet opening of the gearbox housing. The sealing element can abut the rotor shaft housing and the rotating element that drives the gearbox. The sealing element can be arranged, for example, axially and alternatively or additionally radially between the rotor shaft housing and the rotating element that drives the gearbox. Alternatively, the sealing element can abut the gearbox housing and the rotating element that drives the gearbox.The sealing element can, for example, be arranged axially and alternatively or additionally radially between the gearbox housing and the rotating element that forms the drive of the gearbox.

[0016] In one embodiment of the gearbox arrangement, the sealing element may be designed to provide a sealing function essentially only in the direction from the rotor shaft housing to the gearbox housing. For example, oil may flow from the gearbox housing to the rotor shaft housing via the sealing element. Alternatively, the sealing function in the direction from the rotor shaft housing to the gearbox housing may be greater, for example, by a magnitude greater than in the direction from the gearbox housing to the rotor shaft housing. The sealing element may have no or only a minimal sealing function in the direction towards the rotor shaft housing. In this way, the sealing element can function as a kind of one-way valve. This significantly simplifies the design of the sealing element, which is suitable for compensating for positional misalignment.The migration of foreign substances from the gearbox housing into the rotor shaft housing may have little or no impact on the lifespan of the wind turbine. Furthermore, the rotor shaft housing of many wind turbines is regularly cleaned, for example, by flushing. The interior of the rotor shaft housing is often much more easily accessible for such cleaning. For instance, the rotor shaft housing often contains no lubrication but foreign matter that can damage the gearbox. In contrast, the gearbox housing usually only contains lubricating oil, which can then enter the rotor shaft housing. This lubricating oil, once inside the rotor shaft housing, is generally not harmful to the operation of the wind turbine and cannot easily escape into the environment from the rotor shaft housing.

[0017] Alternatively, the sealing element can provide essentially the same level of sealing in both directions. This also allows the rotor shaft housing to be additionally protected from foreign substances, such as lubricating oil from the gearbox.

[0018] In one embodiment of the gearbox assembly, the sealing element may have a flexible sealing lip. The sealing lip may, for example, extend radially inwards or outwards. The sealing lip may, for example, project from a base section of the sealing element. The sealing lip may be more flexible than the base section. The sealing lip may also be thinner than the base section. Furthermore, the sealing lip may be made of a different material than the base section. The sealing lip may, for example, rest against the rotor shaft housing or the gearbox housing. The base section may, for example, rest against the rotating element that drives the gearbox. A reversed arrangement is also possible. The flexible sealing lip can, for example, compensate particularly well for positional deviations. The base section can improve the retention of the sealing element.The base section can be, for example, inflexible or less flexible than the sealing lip. This makes it particularly easy to hold the sealing element in position. For example, the base section can rest against two opposing axial stops. The base section can also be fixed to another component of the gearbox assembly using one or more fasteners, such as screws.

[0019] In one embodiment of the gearbox arrangement, the flexible sealing lip can be curved axially towards the interior of the rotor shaft housing. The sealing lip can also be curved towards the rotor of the wind turbine. Alternatively, the sealing lip can form a concave curve facing the interior of the rotor shaft housing or a convex curve facing the interior of the gearbox housing. The sealing lip can be curved, for example, in the installed state and, alternatively or additionally, in an unloaded state. The curvature of the sealing lip can increase flexibility to compensate for positional deviations. The curvature can also enhance the sealing effect in one direction. For example, the curvature of the sealing lip can form a corner. The sealing lip can also be curved relative to its base section. Finally, the sealing lip can have both straight and curved sections.

[0020] In one embodiment of the transmission assembly, the sealing element can be designed as a discontinuous element in the circumferential direction. The sealing element can, for example, be formed from an elongated piece. For instance, the sealing element can be formed as a rope-like structure before its assembly. The sealing element can be manufactured, for example, using a continuous casting process. Optionally, it can be cut to a desired length. The elongated piece can be joined at its free ends, for example, before or after the assembly, by gluing, welding, or a connecting element. This allows, for example, a sealing effect to be provided along the entire circumference. However, the sealing element can also have a gap in its circumferential direction, or at least the free ends can remain unjoined. This can be more cost-effective.The sealing element can thus be manufactured much more cost-effectively and installed as an alternative or additional component compared to, for example, an O-ring. An O-ring, for instance, is cast directly as a closed ring. In typical wind turbines, the diameter in the area of ​​the sealing element can be approximately 2 meters, which is why continuous circumferential sealing elements are often only available as expensive custom-made products.

[0021] In one embodiment of the transmission arrangement, the gear set may be configured as a planetary gear set. A planetary gear set is configured, for example, as a negative planetary gear set or a positive planetary gear set. A planetary gear set comprises, for example, a sun gear, a planet carrier, and a ring gear. The sun gears, planet carrier, and ring gears of a planetary gear set form, for example, its rotating elements. Accordingly, the planet carrier, the sun gear, or the ring gear may, for example, provide the drive for the transmission. Each planetary gear set may have one or more planet gears, which are rotatably mounted on the planet carrier. The planet gears may be mounted on the planet carrier via planet pins. The planet pins may be formed separately or integrally with the carrier element. The planet gears may be rotatably mounted on the planet pins.The planetary gears can be mounted on the carrier element in a rotatable manner, either alternatively or additionally. For example, the planet gears of a planetary gear set mesh with a sun gear and a ring gear of another planetary gear set. A rotational axis of a planetary gear set can correspond to a rotational axis of the rotating elements. Individual planetary gear sets can, for example, be arranged coaxially with the rotor shaft. The transmission can also have several planetary gear sets that are mechanically interconnected. For example, the output can also be formed by a rotating element of a second planetary gear set.

[0022] In one embodiment of the transmission arrangement, the rotating element that drives the transmission can be designed as the planet carrier for the planetary gear set. This can result in a favorable gear ratio. Furthermore, the sealing of the rotor shaft housing to the transmission housing can be particularly simple thanks to the sealing element on the planet carrier. The planet carrier can, for example, be designed with a large radial extent without significantly affecting the effective diameter of the individual gear teeth. For instance, a planet carrier can have a radially extending wall to which the respective planet pins are attached. This radially extending wall can face the interior of the rotor shaft housing and largely seal off the interior of the transmission housing.

[0023] In one embodiment of the gearbox arrangement, the rotating element that drives the gearbox can be mounted on the rotor shaft. The rotating element that drives the gearbox can only be mounted on the rotor shaft of the wind turbine. For example, the planet carrier is mounted on the rotor shaft of the wind turbine. The planet carrier can only be mounted on the rotor shaft of the wind turbine. The rotating element that drives the gearbox can then be simply mounted on the rotor shaft, for example, by a bolted or press-fit connection. The rotating element that drives the gearbox can be connected directly or indirectly to the rotor shaft for its mounting. The rotating element that drives the gearbox is, for example, not mounted on the gearbox housing, neither directly nor indirectly.

[0024] A second aspect concerns a wind turbine. The wind turbine has a gearbox arrangement as described in the first aspect. The respective advantages and further characteristics can be found in the description of the first aspect, whereby embodiments of the first aspect also form embodiments of the second aspect and vice versa. The wind turbine may have a rotor. The rotor is, for example, permanently and non-rotatably connected to the rotor shaft of the wind turbine. The rotating element that drives the gearbox, such as the planet carrier, may be mounted on the rotor shaft of the wind turbine. For example, the rotating element that drives the gearbox may be mounted exclusively on the rotor shaft of the wind turbine. In this case, no other bearings directly support the rotating element that drives the gearbox.However, it may be, for example, that the rotary element which forms the drive of the gearbox is additionally supported at its teeth and thus operative connections with other rotary elements, for example by these respective other rotary elements. Brief description of the characters Fig. Figure 1 schematically illustrates a wind turbine with a gearbox arrangement. Fig. Figure 2 schematically illustrates, in a side sectional view, details of a seal for a gearbox housing against the ingress of foreign substances from a rotor shaft housing in the gearbox arrangement of the wind turbine of Fig. 1 according to a first embodiment. Fig. Figure 3 schematically illustrates, in a side sectional view, details of the sealing of the gearbox housing against the ingress of foreign substances from the rotor shaft housing in the gearbox arrangement of the wind turbine of Fig. 1 according to a second embodiment. Fig. Figure 4 schematically illustrates in a sectional view a cross-section of a sealing element for sealing the gearbox housing against the ingress of foreign substances from the rotor shaft housing in the gearbox arrangement of the wind turbine of Fig. 1. Detailed description of embodiments

[0025] Fig. Figure 1 illustrates a horizontally oriented wind turbine 10. The wind turbine 10 has a rotor 12, which is held on a rotor shaft 16 via a hub 14. The axis of rotation of the rotor shaft 16 extends essentially horizontally. The rotor shaft 16 is supported by two slant roller bearings 18 in a rotor shaft housing 70, which is located inside the nacelle 20. The rotor shaft 16 is mechanically connected to a generator 24 via a gearbox 22. A brake 26 is also arranged in the operative connection between the gearbox 22 and the generator 24. The nacelle 20 is rotatably mounted at the upper end of a tower 28, which is anchored to the ground. In another embodiment, the wind turbine 10 is designed as an offshore turbine. In addition to the tower 28, the wind turbine 10 also has a grid connection 30.

[0026] In the illustrated embodiment, the gearbox 22 has two gear sets designed as planetary gear sets, although other designs are also possible. The gear sets are arranged in the interior of a gearbox housing 36. A planet carrier 38 facing the rotor 12 forms a drive for the gearbox 22. For this purpose, the planet carrier 38 is permanently and rotationally fixed to the rotor shaft 16 via a radially external or internal toothing. However, due to tolerances, this toothing can allow slight tilting and, alternatively or additionally, translational displacement of the planet carrier 38 relative to the rotor shaft 16. Furthermore, the planet carrier 38 can also tilt and, alternatively or additionally, be translationally displaced due to loads on the rotor 12 and the resulting bending of the rotor shaft 16. This can lead to positional deviations of the planet carrier 38.For example, the planet carrier 38 can have an angular deviation and an eccentricity to a nominal position within the gearbox housing 36 and thus also relative to the gearbox housing 36.

[0027] The wind turbine 10 has a gearbox assembly comprising at least the gearbox 22 and a rotor shaft assembly. The rotor shaft 16, the two rolling bearings 18, and the rotor shaft housing 70 are at least part of the rotor shaft assembly. The rotor shaft housing 70 and the gearbox housing 36 are fixed to one another, for example, by being flanged together. The gearbox assembly also includes a sealing element 72. The sealing element 72 is designed to seal the gearbox housing 36 against the ingress of foreign substances from the rotor shaft housing 70. Furthermore, the sealing element 72 is designed to compensate for the positional deviation of the rotating element, which serves as the drive for the gearbox 22 (i.e., the planet carrier 38), relative to the gearbox housing 36 and, alternatively or additionally, to the rotor shaft 16 during the sealing process. The positional deviation does not impair the sealing function.

[0028] In Fig. Figure 2 shows a detailed view of the arrangement of the sealing element 72. The sealing element 72 is, at least in a first exemplary embodiment, as shown in Fig. 4 shown trained. As in Fig. As can be seen in Figure 4, the sealing element 72 has a base section 80 and a sealing lip 82 extending radially outwards from it. The base section 80 of the sealing element 72 rests against the circumference of the planet carrier 38. The planet carrier 38 has a smooth, axially extending circumferential contact surface in this area. Radially on the outside, the sealing element 72 rests against the rotor shaft housing 70 with its sealing lip 82. In the example shown, the rotor shaft housing 70 is a cast component and has been machined in the area of ​​the contact surface of the sealing lip 82 to create a smooth, axially extending circumferential contact surface. Furthermore, the rotor shaft housing 70 has a radially inwardly projecting projection, which forms an axial stop for the base section 80 or can otherwise define an axial position of the sealing element 72 towards the interior of the gearbox housing 36.In another embodiment not shown, the planet carrier 38 alternatively or additionally has a radially outwardly projecting projection which forms an axial stop for the base section 80 or can otherwise specify an axial position of the sealing element 72 in the direction of the interior of the rotor shaft housing 70.

[0029] In Fig. Figure 3 shows a second embodiment in which the sealing element 72 is mounted differently. Only the differences are explained. In the second embodiment, the sealing element 72 is screwed to a radially outwardly projecting projection of the planet carrier 38 by means of a fastening element 84, here a screw. This axially fixes the sealing element 72. Since the sealing element 72 is designed as an elastic component, a washer 86 is arranged between the fastening element 84 and the base section 80, which improves the fixation.

[0030] In Fig. Figure 4 shows a cross-section of an embodiment of the sealing element 72. The base section 80 has a rectangular cross-sectional shape. The sealing lip 82 is flexibly connected to the base section 80 via a narrow section 88. The narrow section 88 represents a material taper that forms a kind of hinge between the sealing lip 82 and the base section 80. This increases the flexibility of the sealing lip 82 when it deforms relative to the base section 80. The flexible sealing lip 82 is also curved axially towards the interior of the rotor shaft housing 70. The sealing element 72 is designed to protect the gearbox housing 36 against the ingress of foreign substances from the rotor shaft housing 70 between the planet carrier 38 and the rotor shaft housing 70.In contrast, the sealing effect against foreign substances attempting to pass from the gearbox housing 36 into the rotor shaft housing 70 between the rotor shaft housing 70 and the planet carrier 38 is minimal, as the sealing lip 82 can be bent axially to the left towards the interior of the rotor shaft housing 70 with minimal force. Bending in the opposite direction, however, requires considerably more force. The sealing element 72 is thus designed to provide essentially only a sealing function in the direction from the rotor shaft housing 70 to the gearbox housing 36.

[0031] The sealing element 72 is in the example shown in Fig.4 is designed as a one-piece element made of an elastic material, such as rubber or TPU. The sealing element 72 is manufactured from an elastic element, which is produced cost-effectively as a rope-like structure using a continuous casting or extrusion process. In the circumferential direction, the sealing element 72 is thus designed as a discontinuous element. The sealing element 72 has two free ends of the rope-like structure, which lie against each other in the circumferential direction. In another embodiment, these two ends of the rope-like structure are joined together to form the sealing element 72, for example by welding or bonding. In yet another embodiment, the sealing element 72 is cast directly as a circumferentially closed ring. Reference sign 10 wind turbines 12 Rotor 14 hub 16 Rotor shaft 18 rolling bearings 20 gondolas 22 gearboxes 24 Generator 26 brake 28 Tower 30 network connection 36 Gearbox housings 38 planetary carriers 70 Rotor shaft housings 72 Sealing element 80 Basic section 82 Sealing lip 84 Fastening element 86 Washer Section 88

Claims

[1] Gear arrangement for a wind turbine (10) comprising a gearbox (22) and a rotor shaft arrangement, wherein the gearbox (22) has a gearbox housing (36) and a gear set arranged in an interior of the gearbox housing (36), wherein a rotating element (38) of the gear set forms a drive of the gearbox (22), wherein the rotor shaft arrangement comprises a rotor shaft housing (70), wherein the rotating element (38) is permanently and rotationally fixedly connected to a rotor shaft (16) of the rotor shaft arrangement, wherein the gearbox housing (36) and the rotor shaft housing (70) are fixed to one another, and wherein the gearbox arrangement comprises a sealing element (72), wherein the sealing element (72) is configured to seal the gearbox housing (36) against the ingress of foreign substances from the rotor shaft housing (70) and wherein the sealing element (72) is further configured to compensate for a positional deviation of the rotating element (38) relative to the gearbox housing (36) during sealing. [2] Gear arrangement according to claim 1, characterized by , that the sealing element (72) seals the gearbox housing (36) against the ingress of foreign substances from the rotor shaft housing (70) through a gap between the rotating element (38) and the rotor shaft housing (70). [3] Gear arrangement according to claim 1 or 2, characterized by , that the sealing element (72) is designed to provide a sealing function only essentially in the direction from the rotor shaft housing (70) to the gearbox housing (36). [4] Gear arrangement according to one of the preceding claims, characterized by , that the sealing element (72) has a flexible sealing lip (82). [5] Gear arrangement according to claim 4, characterized by , that the flexible sealing lip (82) is curved axially towards an interior of the rotor shaft housing (70). [6] Gear arrangement according to one of the preceding claims, characterized by, that the sealing element (72) is designed as a circumferentially discontinuous element. [7] Gear arrangement according to one of the preceding claims, characterized by that the gear set is designed as a planetary gear set. [8] Gear arrangement according to claim 7, characterized by , that the rotating element (38) is designed as a planet carrier (38) of the planet gear set. [9] Gear arrangement according to any one of the preceding claims, characterized by , that the rotating element (38) is mounted on the rotor shaft (16). [10] Wind power plant (10) with a gearbox arrangement according to one of the preceding claims and a rotor (12) which is permanently connected to the rotor shaft (16) in a rotationally fixed manner.

Images