Gear arrangement and wind turbine

Abstract

The invention relates to a gearbox arrangement for a wind turbine (10). A gearbox (22) comprises at least one gearbox housing (36) and a planetary gear set (32) arranged therein. A planet carrier (38) of the planetary gear set (32) forms a drive of the gearbox (22), wherein the planet carrier (38) is mounted on a rotor shaft (16) of the wind turbine (10) in the assembled wind turbine (10). The gearbox housing (36) has a radially extending end section (50) at an end facing a rotor (12) of the wind turbine (10) in the assembled wind turbine (10). The gearbox arrangement also includes a sealing element (52) which seals the radially extending end section (50) with the planet carrier (38) in order to seal an interior of the gearbox housing (36) on the rotor side. The invention further 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. Due to their size, modern wind turbines are typically transported to the installation site in several parts and assembled on-site. Parts of the gearbox are mounted on the rotor shaft, meaning the gearbox is only enclosed once the wind turbine is assembled, for example, in a gearbox housing. Consequently, the gearbox is often elaborately protected from contamination during transport, before assembly, and during the installation of the wind turbine, as contamination could otherwise reduce the turbine's lifespan and efficiency.Alternatively or additionally, cleaning can also be carried out during assembly, for example by flushing. This is also complex and expensive. 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, for example, 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, for example, have two, three, four, or more rotor blades, which are connected to the rotor shaft via a hub.

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

[0005] The transmission features a planetary gear set arranged within the interior of the transmission housing. A planetary gear set can be 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. Each planetary gear set can have one or more planet gears, which are rotatably mounted on the planet carrier. The planet gears can be mounted on the planet carrier via planet bolts. The planet bolts can be formed separately from or integrally with the carrier element. The planet gears can be rotatably mounted on the planet bolts. Alternatively or additionally, the planet bolts can be rotatably mounted on the carrier element.For example, the planet gears of a planetary gear set each 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.

[0006] The planet carrier of the planetary gear set forms the drive of the gearbox. The planet carrier can form an input shaft of the gearbox. The planet carrier can be a single piece or a multi-piece design. For example, the planet carrier has an axial shaft section at its end facing the rotor when assembled. For example, the planet carrier can be permanently and rotationally fixed to the rotor shaft in the assembled wind turbine. For example, the planet carrier and the rotor shaft can have corresponding gear teeth through which they engage. The rotor shaft and the planet carrier can be arranged coaxially. The ring gear or sun 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.

[0007] The planetary carrier is mounted on the rotor shaft of the assembled wind turbine. In the assembled wind turbine, the planetary carrier can only be mounted on the rotor shaft. For example, the rotor shaft can be mounted to the nacelle via two roller bearings. High loads can act on the rotor shaft due to the rotor, which is why mounting it close to the rotor allows for smaller bearings. For example, the rotor shaft is mounted to the nacelle with two roller bearings. The planetary carrier can then be easily mounted to the rotor shaft, for example, by means of a bolted or press-fit connection. The planetary carrier can be connected to the rotor shaft for its mounting either directly or indirectly. For example, the planetary carrier is not mounted to the gearbox housing, neither directly nor indirectly. The rotor shaft can be part of the gearbox assembly or considered a separate component.In its unassembled state, the planetary carrier is not mounted in the same way as when ready for operation. For example, during transport to the gearbox housing, the planetary carrier is secured with clamps, sleeves, bolts, screws, or other clamping elements to prevent unwanted movement and damage to the gearbox during transport. During assembly, this securing mechanism can be released and the corresponding clamping elements removed.

[0008] The gearbox housing has a radially extending end section at the end facing a rotor of the assembled wind turbine. This end section can extend to the planet carrier, in particular to an axial shaft section of the planet carrier that forms the input shaft. A gap between the radially extending end section and the planet carrier can have a width suitable for sealing by a gasket. For example, the gap can be approximately half the height of a typical O-ring of the corresponding diameter. The radially extending end section can, for example, be a circumferential axial wall. The radially extending end section can have an annular shape. The wall can, for example, be essentially free of loads applied by the gearbox during operation. The radially extending end section can be non-load-bearing.The radially extending end section can, for example, be designed solely for sealing and optionally for oil lubrication of the gearbox or even just the planetary gear set. This radially extending end section, for instance, has no load-bearing properties. The wall cannot, for example, form a bearing section for rotating parts of the gearbox or the wind turbine as a whole. An end of the planet carrier facing the rotor in the assembled wind turbine extends, for example, from the housing, perhaps through a central through-opening in the radially extending end section of the housing. This section of the planet carrier can, for example, be connected to the rotor shaft in the assembled state, so that the planet carrier is supported by it.

[0009] The gearbox assembly features a sealing element that seals the radially extending end section against the planet carrier to seal the interior on the rotor side. This sealing can be achieved at least in the unassembled state of the wind turbine. The sealing element can therefore seal the interior of the gearbox housing before assembly, for example, at least until the rotor shaft is mounted to the planet carrier. After assembly, however, the sealing element may be superfluous, as the gearbox may be sealed on the rotor side by the rotor shaft bearing. The sealing effect of the sealing element may be lost during operation. However, the sealing element can also be designed to provide a seal during operation, thereby allowing relative rotation of a component such as the planet carrier.The sealing element can, for example, seal the gearbox housing against a housing for the rotor shaft bearings, such as the nacelle or a separate inner housing. Furthermore, minor leaks from the gearbox may not affect its service life or performance, unlike, for example, dirt and water that may have entered the gearbox before assembly. This eliminates the need for corresponding covers before, during, or even during transport. The sealing element also does not need to be removed after or during the assembly of the wind turbine. This significantly simplifies the transport and installation of the wind turbine. For example, the sealing element remains in place within the gearbox even after the wind turbine has been assembled.

[0010] The sealing element seals, for example, a radial gap between the radially extending end section and the planet carrier, for instance, by means of an axial and, alternatively or additionally, radial arrangement between the radially extending end section of the gearbox housing and the planet carrier. The sealing element can be in direct contact with the radially extending end section of the gearbox housing. The sealing element can be in direct contact with the planet carrier. However, the sealing element can also seal indirectly, for example, by contacting an additional component, such as an oil guide component or a retaining ring, with which the sealing element is attached to the planet carrier and, alternatively or additionally, to the gearbox housing. The sealing element can be a separate component. In this case, its manufacture can be cost-effective. However, the sealing element can also be integrally formed within other components.For example, the sealing element can be molded onto the planet carrier, the gearbox housing, or even a ring that holds the planet carrier in the gearbox housing during transport. Alternatively, the sealing element can be injection-molded onto a plastic oil guide component. In this case, separate installation of the sealing element may not be necessary.

[0011] In one embodiment of the gear assembly, the radially extending end section may be designed to supply oil to the planetary gear set for lubrication. For this purpose, the radially extending end section may, for example, have oil channels. This can be used, for example, to lubricate several or just one of the rotating elements. For example, the radially extending end section can be used to lubricate the planetary pins of the planet carrier and, alternatively or additionally, the planet gears. This allows the gear assembly to be compact, since the radially extending end section is used not only for sealing before assembly but also for supplying the gear assembly with lubricating oil.If multiple planetary gear sets are used, a radially extending oil channel, for example formed by a housing element, between the two planetary gear sets, which would otherwise serve for lubrication, can be replaced. This allows the gearbox to have a short axial length.

[0012] In one embodiment of the gear assembly, the gear assembly may include an oil guide element. The oil guide element may be designed to direct oil from the radially extending end section to the planet carrier for its lubrication. For example, the oil guide element may also axially define an oil passage towards the rotor. The oil guide element may, for example, be made of a plastic component. The oil guide element may, for example, be screwed to the radially extending end section. The oil guide element may, for example, be mounted downstream of the sealing element and retain the sealing element. The oil guide element may also form the sealing element itself. The oil guide element may be designed as a retaining ring. For example, the oil guide element may be arranged radially and, alternatively or additionally, axially between the radially extending end section and the planet carrier.The sealing element can, for example, be in contact with the oil guide element and the planet carrier.

[0013] In one embodiment of the gearbox arrangement, the planet carrier may have at least one oil channel extending axially from an end facing the rotor in the assembled wind turbine to a planet bolt of the planet carrier. This allows oil to be guided from the radially extending end section to the planet carrier. For example, the oil channel may be formed by two sections in the planet carrier. The oil channel may also be formed by an axial bore in the planet carrier. Alternatively, the oil channel may have a channel element, such as a pipe. One such oil channel may be provided for each planet bolt. However, a single oil channel or a different number of oil channels may also be provided. The oil channel may serve to lubricate the planet carrier.The oil channel can be fluidically connected to the oil guide element and alternatively or additionally to an oil guide in the radially extending end section.

[0014] In one embodiment of the gearbox arrangement, the gearbox may feature an oil return system facing the rotor in the assembled wind turbine. This oil return system can be designed to return oil to the interior of the gearbox housing. This allows oil that leaks from the rotor side during operation to be pumped back into the gearbox housing. The oil return system may include appropriate elements for guiding the oil and / or corresponding oil channels. For example, a rotor-side inlet opening for the oil return system can be arranged radially inward to an outlet opening that leads into the interior of the gearbox housing. This allows the rotation of the gearbox and the operation of the wind turbine to create a pumping effect, thus eliminating the need for a separate pump for the oil return system.

[0015] In one embodiment of the transmission arrangement, the transmission arrangement may include a return element. The return element may be located on the rotor side, next to the transmission housing, outside the interior. The return element may have an oil channel extending at least partially radially outward. Radially outward extending can mean that an inlet opening is located radially inside an outlet opening. The return element can, for example, collect oil that has escaped from the rotor side of the interior and return it to the interior. The return element may form the sealing element. The return element may hold the sealing element. The sealing element may be located between the return element and the planet carrier. The return element may be arranged axially adjacent to the radially extending end section.The return element can, for example, be designed as a plastic component. The return element can be fluidically connected to the interior of the gearbox housing. For example, the radially extending end section can have an axial through-opening that fluidly connects the return element to the interior of the gearbox housing. The oil return element can provide axial retention for the previously described oil guide element. For example, this axial retention can be a retaining ring connected to the planet carrier, for instance, by a screw connection. Alternatively, a separate retaining ring or a retaining ring without an oil return function can be provided.

[0016] In one embodiment of the transmission arrangement, the sealing element can be positioned between the return element and the planet carrier. This allows for easy installation and retention of the sealing element. Furthermore, this eliminates the need for a sealing seat or similar feature on the transmission housing for the sealing element.

[0017] In one embodiment of the transmission arrangement, the radially extending end section may have a through-opening designed for oil return to the interior of the transmission housing. This through-opening extends, for example, axially. This through-opening is, for example, arranged radially outside the sealing element and also radially outside a lubricating oil supply.

[0018] In one embodiment of the gearbox arrangement, the sealing element may be designed as a temporary seal. A temporary seal, for example, may not seal at all or only initially during operation of the wind turbine. For instance, the sealing element may be designed to wear out quickly and lose its sealing effect during operation of the assembled wind turbine. The sealing element may not be designed to accommodate relative movement between the two sealed components. For example, the sealing element may only seal during transport and assembly. During operation of the wind turbine, the temporary sealing element may lose its sealing effect after a short time or may, for example, slip out of place. This can make the sealing element very cost-effective. For example, no sealing may be required during operation.

[0019] A second aspect concerns a wind turbine. The wind turbine has a rotor. The rotor is permanently and rotationally fixed to a rotor shaft of the wind turbine. The wind turbine has a gearbox assembly 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 planet carrier is mounted on the rotor shaft of the wind turbine. For example, the planet carrier may be mounted exclusively on the rotor shaft of the wind turbine. In this case, no other bearings directly support the planet carrier. However, it is possible that the gear teeth of the planetary gear set, and thus the operative connection with other rotating elements, provide at least additional support for the planet carrier. The rotor shaft may be permanently and rotationally fixed to the planet carrier of the gearbox assembly. Brief description of the characters Fig. Figure 1 schematically illustrates a wind turbine. Fig. Figure 2 schematically illustrates a rotor shaft and gearbox of the wind turbine in a side sectional view. Fig. Figure 3 schematically illustrates in a side sectional view a first embodiment of a gearbox arrangement for the wind turbine of Fig. 1. Fig. Figure 4 schematically illustrates in a side sectional view details of the first embodiment of the gearbox arrangement for the wind turbine of Fig. 1. Fig. Figure 5 schematically illustrates in a side sectional view details of a second embodiment of the gearbox arrangement for the wind turbine of Fig. 1. Detailed description of embodiments

[0020] 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 in a nacelle 20 by two rolling bearings 18. 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.

[0021] In Fig. Figure 2, a schematic sectional view, illustrates a key concept of the present disclosure. Shown here is the rotor shaft 16 with the two rolling bearings 18. The gearbox 22 is flanged to the rotor shaft 16. In the example shown, the gearbox 22 has a first rotor-side planetary gear set 32 ​​and a second generator-side planetary gear set 34. The two planetary gear sets 32 and 34 provide a gear ratio for transmitting the torque introduced by wind at the rotor 12 to the generator 24. The two planetary gear sets 32 and 34 are arranged in an interior space of the gearbox housing 36.

[0022] During the assembly of the wind turbine 10, the rotor 12, the rotor shaft 16 with its roller bearings 18, and the gearbox 22 are first transported separately to an installation site and only assembled there. As, for example, in Fig. As can be seen in Figure 2, a planet carrier 38 of the first planet gear set 32 ​​forms an input shaft of the gearbox 22, which is permanently and rotationally fixed to the rotor shaft 16. The planet carrier 38 of the first planet gear set 32 ​​is supported only, or at least primarily, by the rotor shaft 16. It is also evident that the gearbox housing 36 is open to the rotor shaft 16 at its rotor-side end, and the interior of the gearbox housing 36 is open at this point. During transport and assembly, water, foreign objects, and other contaminants can therefore enter. This may necessitate extensive protection against such ingress and, alternatively or additionally, flushing after assembly, which is very complex.

[0023] The gearbox housing 36 according to Fig. 2 has an intermediate housing element 40 axially between the two planet gear sets 32, 34. This intermediate housing element 40 has no load-bearing function and does not provide surfaces for the arrangement of a bearing on it, but it does have a wall extending radially inwards. This wall serves to supply lubricating oil to the respective planet pins 42 of the planet carrier 38.

[0024] To protect the gearbox 22 from contamination during transport and assembly, this wall is displaced axially towards the rotor. This is in Fig. 2 already illustrated with lines 44. The radially inward extending wall between the two planetary gear sets 32, 34 can therefore also be omitted, thus giving the transmission 22 a further short axial extent.

[0025] As in Fig. As can be seen in Figure 3, the gearbox housing 36 has a radially extending end section 50 at an end facing the rotor 12 in the assembled wind turbine 10. This radially extending end section 50 serves both to supply lubricating oil to the planetary pins 42 of the planet carrier 38 of the first planetary gear set 32 ​​and to seal the gearbox housing 36 on the rotor side, at least before final assembly. A sealing element 52 is also provided for this purpose. Details of embodiments of this arrangement are described in Fig. 4 and Fig. Figure 5 illustrates this. The wind turbine 10 now has an oil channel 52 extended to this end section 50, which previously supplied the intermediate housing element 40 with oil.

[0026] The radially extending end section 50 has one or more radially extending through-openings (not shown) serving as oil channels, which are fluidically connected to the oil channel 52. An oil guide element 54 is arranged radially on the inside of the radially extending end section 50, between a shaft section of the planet carrier 38, which is permanently and rotationally fixed to the rotor shaft 16, and the radially extending end section 50. The oil guide element 54 is designed to direct oil from the radially extending end section 50 to the planet carrier 38 for its lubrication. For this purpose, the oil guide element 54 is stepped on its side facing the radially extending end section 50. This creates a labyrinth-like structure that reduces axial leakage towards the rotor 12.The planet carrier 38 has at least one oil channel 56 extending axially from an end facing the rotor 12 in the assembled wind turbine 10 to a planet bolt 42 of the planet carrier 38 and, alternatively or additionally, to the planet gears on the planet carrier 38. This oil channel 56 is fluidically connected to the oil guide element 54. In this case, the oil channel 56 is formed by two through-bores in two axial wall regions of the planet carrier 38, in which a guide element 58 is arranged.

[0027] The oil guide element 54 is held axially on the rotor side by a retaining ring 60, which is screwed or otherwise fastened to the radially extending end section 50. In the first embodiment, this retaining ring 60 is designed as a return element 60 facing the rotor 12 in the assembled wind turbine 10. The return element 60 is part of an oil return system facing the rotor 12 in the assembled wind turbine 10, which is designed to return oil in the area of ​​the rotor shaft 16 and its rolling bearings 18 back into the interior of the gearbox housing 36. For this purpose, the return element 60 has an oil channel 62 extending at least partially radially outwards, the inlet opening of which is arranged radially inwards to an outlet opening. In addition, the oil return system has an axially extending through-opening 64 in the planet carrier 38, which is arranged radially outwards to the oil channel 56.The through-opening 64 is fluidically connected to the oil channel 62. In another embodiment, no such oil return is provided. Such an embodiment is, for example, described in [reference]. Fig. 4 illustrates.

[0028] In the first embodiment, as in Fig. 4. The sealing element 52 is arranged radially as a separate part between the return element 60 and the shaft section of the planet carrier 38, thus sealing the gearbox housing 36 in the direction of the rotor 12. Alternatively, the sealing element 52 can also bear directly against the radially extending end section 50 or the oil guide element 54 and then seal with the planet carrier 38. An integral design with one of these parts is also possible.

[0029] In Fig. Figure 5 illustrates details of a second embodiment without oil return. Only the differences from the first embodiment are described. In the second embodiment, the sealing element 52 is arranged axially between the retaining ring 60 and the oil guide element 54. The sealing element 52 is integrally formed on the oil guide element 54. Alternatively, the sealing element 52 can also be integrally formed on the retaining ring 60. In yet another embodiment, the sealing element 52 is also designed as a separate component.

[0030] In one embodiment, the sealing element 52 is designed as a permanent seal, which retains its sealing function even during operation of the wind turbine 10. In other embodiments, the sealing element 54 is designed as a temporary seal. Such a design is used, for example, in Fig.Figure 5 shows that the sealing element 52 is rapidly worn down by a relative movement between the retaining ring 60 and the oil guide element 54 over a short operating period. The material of the sealing element 52 is selected to prevent overheating. 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 32 first planetary gear set 34 second planetary gear set 36 Gearbox housings 38 planetary carriers 40 Intermediate housing element 42 planetary bolts 44 lines 50 radially extending end section 52 Sealing element 54 Oil guide element 56 Oil channel 58 Conductor element 60 Retaining ring / return element 62 more oil channels 64 Passage opening

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