Lubrication system, drive train and wind turbine

Abstract

The invention relates to a lubrication system for a gearbox of a drive train of a wind turbine (10), which is designed to lubricate a planetary gear set (60) of the gearbox (22). The lubrication system has an oil cooler (54) and an oil channel (80, 92, 100) in a metallic component of the gearbox (22). The lubrication system is designed to supply lubricating oil from the oil cooler (54) through the oil channel (80, 92, 100) to a lubrication area (56). The lubrication system has insulation (84, 86, 96, 102) which is designed to thermally insulate the lubricating oil in the oil channel (80, 92, 100) from the metallic component, at least in certain areas. The invention also relates to a drive train and a wind turbine (10).

Description

[0001] The present invention relates to a lubrication system for a gearbox of a wind turbine drive train. Furthermore, the invention relates to a wind turbine drive train and a wind turbine itself. 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. The gearbox is lubricated during operation to minimize wear and achieve high efficiency. The gearbox heats up during operation, for example, due to friction in the bearings and meshing gears. This can also cause the lubricating oil to heat up as it flows through the gearbox, reducing its viscosity. Due to the lower viscosity, lubrication performance can decrease and wear can increase. To cool the oil, it can be passed through an oil cooler.Nevertheless, the lubricating oil can become very hot and its viscosity can decrease accordingly before reaching the respective points to be lubricated, for example due to the high thermal conductivity of metallic components through which it flows.

[0003] DE 10 2023 115 197 A1 discloses an electrically operated axle drive train for a motor vehicle comprising an electric machine for driving the motor vehicle, which can be powered by an inverter and is housed in a motor housing at least partially made of metal, comprising a stator and a rotor rotatable thereto, and a transmission assembly housed in a transmission housing at least partially made of metal, which is arranged in the torque path between the electric machine and at least one wheel of the motor vehicle. The transmission cooling path is made, at least in the metal sections of the transmission housing, at least partially from a material different from the metal of the transmission housing, wherein the material different from the metal of the transmission housing has a lower thermal conductivity than the metal of the transmission housing.

[0004] From DE 10 2021 115 337 A1, a planetary gearbox for a gas turbine engine of an aircraft is known, comprising at least one rotatable planet carrier and at least one planet pin non-rotatably connected thereto. At least one planet gear is rotatably mounted on the planet pin via a plain bearing. In the region of the planet pin, the plain bearing is designed with an oil supply pocket connected to at least one oil supply channel provided in the planet pin. A flow limiting unit is provided in the oil supply channel, limiting the oil flow rate from the oil supply channel towards the oil supply pocket.The oil supply channel and the flow limiting unit of the oil supply channel are designed to introduce the oil volume flow at least approximately parallel to an axial extension direction of the sliding bearing into an oil chamber in the planetary bolt, which is provided in the flow direction of the oil volume flow between the flow limiting unit and the oil supply pocket and which is fluidically connected to the oil supply pocket via at least one oil channel, wherein the oil channel opens into the oil supply pocket in a circumferential side of the planetary bolt. Description of the invention

[0005] One aspect concerns a lubrication system for the gearbox of a wind turbine's drive train. The wind turbine may have a nacelle in which the drive train is mounted. The nacelle may have a machine bed. The wind turbine may have a tower on which the nacelle is mounted. The tower extends, for example, in a vertical direction. The nacelle may be mounted on the tower, either rotatably or fixedly. The nacelle may be located on the top of the tower. The tower may be hollow. The tower may taper towards its top. The tower may be constructed from several stacked tower sections. The tower may be made of steel and, alternatively or additionally, concrete.

[0006] The drivetrain includes a gearbox. It can also include a rotor, a generator, and a rotor shaft. The rotor drives the generator via the gearbox to produce electrical energy. The gearbox converts the torque applied to the rotor shaft into a torque suitable for the generator. The rotor can be connected to the gearbox via the rotor shaft. The rotor, gearbox, and generator can be mounted, for example, in a nacelle of the wind turbine, perhaps together by a main bearing. The rotor can have a horizontal or 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. The drivetrain can optionally include a brake.

[0007] The transmission features a planetary gear set. A planetary gear set can, for example, have three rotating elements. A planetary gear set can be configured as a positive or negative planetary gear set. The three rotating elements can, for example, consist of a sun gear, a planet carrier, and a ring gear. One or more planet gears can be rotatably mounted to the planet carrier, for example, each on an associated planet pin. In a negative planetary gear set, the planet gears can, for example, mesh with the sun gear and the ring gear. In a positive planetary gear set, for example, two sets of planet gears can be provided. The planet gears of the first set can, for example, mesh with the sun gear and, in pairs, with the planet gears of the second set. The planet gears of the second set can, for example, mesh with the ring gear and, correspondingly, in pairs with the planet gears of the first set.

[0008] The planet carrier of the planetary gear set can, for example, form an input shaft of the gearbox. The input shaft can be connected to the rotor shaft. The ring gear can be fixed to a gearbox housing. The sun gear can form an output shaft of the gearbox. The output shaft can be connected to a rotor of the generator. The gearbox can also have several planetary gear sets connected to each other to provide the gear ratio. All rotating elements of all planetary gear sets can be arranged coaxially. The structural components of the gearbox, such as the gearbox housing, and alternatively or additionally, the respective rotating elements, can be made of a metallic material.

[0009] The lubrication system is designed to lubricate the planetary gear set of the transmission. This involves, for example, lubricating at least one section of the planetary gear set. If multiple planetary gear sets are used, the lubrication system can be designed to lubricate only one, several, or all of these planetary gear sets. The lubrication system can also be designed to lubricate only a specific section or multiple sections of the planetary gear set. Furthermore, the lubrication system can be designed to lubricate other components of the drivetrain, such as the generator and the main bearings. Lubrication can be achieved using a lubricating oil. For example, the lubrication system can lubricate splined connections, one or more meshing gears, one or more rolling bearings, and alternatively or additionally, one or more plain bearings.For example, the lubrication system may be designed to lubricate only or at least all bearings of planetary gears in the gearbox.

[0010] The lubrication system includes an oil cooler. It also features an oil channel within a metallic component of the transmission, such as a planetary gear, transmission housing, or ring gear. The lubrication system is designed to deliver lubricating oil from the oil cooler through the oil channel to a lubrication zone. Multiple lubrication zones can be supplied by a single oil channel or separately by their own dedicated oil channels. The lubrication system may include an oil sump. It may also include a pump that circulates the lubricating oil through the oil cooler and the respective oil channels. The pump can be an electric pump or a mechanical pump driven by the rotor. The pump can be positioned upstream or downstream of the oil cooler.

[0011] The oil channel can, for example, be formed at least partially as a through-opening integrally through the metallic component. The metallic component can at least partially delimit the oil channel. For example, the oil channel can be manufactured as a bore or a cast through-opening in a casting. The oil channel can be partially delimited by other elements. Such elements can be made of metal. The oil channel can have several sections, which are delimited, for example, by different elements and, alternatively or additionally, by metallic components. The oil channel can, for example, have a round or rectangular cross-section.

[0012] The lubrication system incorporates insulation designed to thermally isolate the lubricating oil in the oil channel from the metallic component, at least in certain areas. The insulation can also isolate the entire or nearly the entire oil channel from the metallic component. For example, the insulation can be applied to at least a portion of the oil channel. Compared to a design without such insulation, the insulation can reduce the heating of the lubricating oil in its area due to the metallic component becoming hot during operation. The insulation can have low thermal conductivity. For example, the insulation may have a lower thermal conductivity than the metallic component or channel element, which can be indicated by their respective thermal diffusivity values. The insulation can reduce heat transfer between the lubricating oil and the metallic component in the area of ​​insulation.The insulation is positioned, for example, between the lubricating oil and the metallic component. The insulation can encapsulate the lubricating oil in this area. The insulation can be made of materials such as rubber, foam, fiberglass, or mineral wool.

[0013] Insulation significantly reduces the heating of the lubricating oil as it flows through the metallic components of the gearbox up to the lubrication zone. Wind turbine gearboxes can become very hot and also contain very massive metallic components. Furthermore, wind turbine gearboxes can be very large, for example, compared to vehicle gearboxes. Consequently, the lubricating oil flows through the metallic components for a considerable time before reaching the lubrication zone. In addition, the metallic components store a large amount of heat energy during operation, which can be transferred to the lubricating oil. This can cause the lubricating oil to heat up considerably before it reaches the lubrication zone. Moreover, bearings in wind turbines, for example, are already subjected to very high loads due to the high forces involved. Finally, the maintenance of wind turbines and worn components is extremely complex and costly.For example, with offshore wind turbines, gearbox maintenance may only be possible once a specialized vessel has reached the turbine. Such vessels are typically not readily available and are expensive. Consequently, this can lead to costly downtime of the wind turbine. Insulating the oil channel reduces the heating of the lubricating oil as it flows through the gearbox, thus enabling high-viscosity lubrication. This allows for more reliable lubrication and minimizes wear.

[0014] In one embodiment of the lubrication system, the insulation can be arranged within the oil channel. For example, the insulation can be provided as an insert or coating within the oil channel. The metallic component can be coated on one side bordering the channel with a material of lower thermal conductivity, thus forming the insulation. The insulation can be arranged radially between the lubricating oil and a circumferential wall bordering the oil channel. This allows for easy retrofitting of the insulation. Furthermore, no structural modifications to the metallic components are required compared to a design without insulation. The insulating effect can also be very high. The lubricating oil can penetrate the insulation, or the insulation can be oil-impermeable.The insulation can consist of several layers and may include alternative or additional materials, for example, to encapsulate an oil-sensitive material from the lubricating oil, or alternatively or additionally to support a flexible material. For instance, the insulation might consist of a plastic pipe or hose inserted into the oil channel. Additional insulating material, such as a foam sleeve, may be provided on the outside or inside. The lubricating oil then flows through the plastic pipe or hose on the inside.

[0015] Alternatively, the insulation can be located outside the oil channel. This allows for the easy use of oil-sensitive materials as insulation. The insulation then has no contact with the lubricating oil, for example.

[0016] In one embodiment of the lubrication system, the insulation can be designed as a coating on the metallic component. For example, the coating can be applied to a wall of the metallic component that borders the oil channel. The insulation can be applied as a foam, spray, or liquid, which then adheres to the metallic component within the oil channel. This allows for a cost-effective and, alternatively or additionally, space-saving insulation solution. Alternatively, the insulation can be formed by a separate component from the metallic component. This makes maintenance, replacement, and retrofitting particularly easy.

[0017] In one embodiment of the lubrication system, the metallic component can be configured as the gearbox housing. Alternatively, the metallic component can be configured as the planet carrier of the planetary gear set. Alternatively, the metallic component can be configured as the ring gear of the planetary gear set. Alternatively, the metallic component can be configured as the planet pin. Several or each of these components can also have an oil channel, which is completely or partially thermally insulated by associated insulation within the lubrication system. The oil channels can be interconnected to direct the lubricating oil to a single lubrication area.

[0018] In one embodiment of the lubrication system, the insulation can be designed as an epoxy coating. This can be applied in liquid form and then harden on the metallic component. Alternatively, the insulation can be made of polyurethane, fiberglass, mineral wool, a synthetic foam, calcium silicate, or a highly porous solid. A highly porous solid is also known as an aerogel. A highly porous solid can be, for example, silicate-based, plastic-based, or carbon-based. The highly porous solid can have open or closed cells.

[0019] According to a first aspect of the invention, the lubrication system is designed to lubricate a bearing for a planet gear of the planetary gear set as the lubrication area. The planet gear can be supported, for example, by means of a plain bearing or a rolling bearing. In the case of a plain bearing, the lubricating oil can hydrodynamically separate the planet gear from the component on which it is mounted during operation. This component can be the associated planet pin. According to the first aspect of the invention, the bearing is designed as a radial-axial bearing. In a radial bearing, for example, radial forces are absorbed with respect to an axis of rotation of the planet gear. The radial plain bearing can be formed by an outer circumference on the planet pin and an adjacent inner circumference on the planet gear. In an axial bearing, for example, axial forces are absorbed with respect to an axis of rotation of the planet gear.The axial bearing can be formed, for example, by adjacent end faces of the planetary pin or planet carrier and the planetary pin. The gearbox can have a radial bearing and a double-sided axial bearing for the planetary gear, with the axial bearings being lubricated by lubricating oil exiting the radial bearing.

[0020] The first aspect of the invention provides that the bearing has an oil pocket. The oil pocket can be formed on a circumferential surface of the planetary gear, for example, as a recess. The oil pocket can be formed at an end region of the oil channel. According to the first aspect of the invention, the oil pocket has an opening that points towards the planetary gear. An open side of the oil pocket can face the planetary gear. The opening can be enclosed by a sealing element. The sealing element can be designed as a labyrinth seal. The sealing element can be designed as a polyamide ring. The sealing element can be arranged in the oil pocket. The sealing element can bear against a wall that delimits the opening of the oil pocket. The sealing element can bear against the planetary gear, at least when the gearbox is at rest or also during operation. The sealing element can control the escape of lubricating oil from the oil pocket.The sealing element can ensure sufficient lubrication during start-up. Alternatively, the oil pocket opening in the planetary bolt can also be free of such a sealing element.

[0021] According to a second aspect of the invention, the oil channel in the metallic element forms an oil pocket which has an opening towards a further oil channel. For example, an element extending radially within the gearbox housing can form the oil pocket. The element forming the oil pocket, such as the radially extending element within the gearbox housing, can be a stationary component. Lubricating oil can then flow from there to the rotating planet carrier or another rotating element and into the further oil channel. The further oil channel can therefore be formed in a different element. This other element can also be a metallic element and rotate during operation, either alternatively or additionally. This further element can be a rotating element of the planetary gear set. According to the second aspect of the invention, this opening is also enclosed by a sealing element.Therefore, different oil pockets can be provided, which optionally have different sealing elements. The description of the sealing element above applies analogously here.

[0022] According to the second aspect of the invention, the insulation is formed by the sealing element, for example, at least in the area of ​​the oil pocket. This reduces the number of parts required. The insulation can also be formed as a coating on the sealing element.

[0023] In one embodiment of the lubrication system, the insulation can be arranged on the inside of the sealing element. For example, the insulation can be located between the lubricating oil and the sealing element within the oil pocket. The insulation can be positioned on the side of the sealing element facing the oil pocket and be in contact with the lubricating oil. Alternatively, the insulation can be arranged on the outside of the sealing element. For example, the insulation can be located between the sealing element and the planetary bolt. The insulation can be located on the side of the sealing element facing away from the oil pocket. In this case, the insulation can be free from contact with the lubricating oil. The insulation can have a lower thermal conductivity than the sealing element.

[0024] If the oil channel in the metallic element forms an oil pocket and the bearing for the planetary gear also has an oil pocket, each enclosed by an associated sealing element, these sealing elements and their corresponding insulation can be identical. For example, both sealing elements can integrally form the insulation or be coated on the inside. However, the associated insulation can also be different, for example, with one insulation layer located on the inside of one sealing element and the other on the outside of the other sealing element.

[0025] A second aspect concerns a drive train with a gearbox, which incorporates the lubrication system described in the first aspect. The respective advantages and further features are detailed in the description of the first aspect, whereby embodiments of the first aspect also form embodiments of the second aspect and vice versa. The gearbox includes a planetary gear set. The lubrication system is designed to lubricate the planetary gear set of the gearbox.

[0026] A third aspect concerns a wind turbine with a drive train according to the second aspect and, alternatively or additionally, a lubrication system according to the first aspect. The respective advantages and further characteristics can be found in the descriptions of the first and second aspects, whereby embodiments of the first and second aspects also constitute embodiments of the third aspect, and vice versa. Brief description of the characters Fig. Figure 1 schematically illustrates a wind turbine with a drive train which includes a gearbox. Fig. Figure 2 schematically illustrates a lubricating oil flow in a lubrication system for the gearbox of the drive train of the wind turbine of Fig. 1. Fig. Figure 3 schematically illustrates a planetary gear set of the transmission, which has an oil channel. Fig. Figure 4 schematically illustrates, in a perspective view, the oil channel in a planetary bolt of the planetary gear set of Fig. 3, where no insulation is provided. Fig. Figure 5 schematically illustrates in a perspective view the oil channel in the planetary bolt of the planetary gear set of Fig. 3 with insulation. Fig. Figure 6 schematically illustrates in a sectional view an oil channel in an oil guide element to the planetary bolt with insulation. Fig. Figure 7 schematically illustrates a side view of a ring gear of the planetary gear set with an oil channel. Fig. Figure 8 schematically illustrates in a perspective view of the ring gear of Fig. 7. insulate the oil channel. Detailed description of embodiments

[0027] Fig. Figure 1 illustrates a wind turbine 10 with a horizontal drive train. 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, 38. A rotor bearing housing 40 is provided for this purpose, which is attached to a machine bed 42 of 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, which acts on an input shaft of 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 installation. In addition to tower 28, wind turbine 10 has a grid connection 30.The first of the rolling bearings 18 faces the rotor 12 and is also referred to as the rotor-side bearing 18. The second of the rolling bearings 38 faces the generator 24 and is also referred to as the generator-side bearing 38. Both rolling bearings 18 and 38 are designed as tapered roller bearings. At least the rotor bearing housing 40, the rotor 12, the rotor shaft 16, the gearbox 22, and the generator 24 form components of the drive train of the wind turbine 10.

[0028] Fig. Figure 2 schematically illustrates a lubrication system for the gearbox 22 of the wind turbine 10. The lubrication system has an oil sump 50, which is formed by an oil pan, and a pump 52. The pump 52 pumps lubricating oil from the oil sump 50 through an oil cooler 54 of the lubrication system to a lubrication area 56. The lubricating oil is pumped through one or more oil channels formed in metallic components of the gearbox 22. These metallic components heat up during operation and can therefore also heat the lubricating oil flowing through them.

[0029] In Fig. Figure 3 illustrates a planetary gear set 60 of the transmission 22, which is connected to the lubrication system of Fig. The planetary gear set 60 comprises a sun gear 62, a planet carrier 64, and a ring gear 66 as rotating elements. The planet carrier 64 forms an input shaft for the gearbox 22 and is connected to the rotor shaft 16. The ring gear 66 is fixed to a gearbox housing. The sun gear 62 forms an output shaft for the gearbox 22 and is connected to a rotor of the generator 24. A plurality of planet gears 68 are rotatably mounted on the planet carrier 64, specifically on associated planet pins 70 of the planet carrier 64. The planet gears 68 mesh with both the ring gear 66 and the sun gear 62.

[0030] Each planetary bolt 70 is designed as a metallic component in which an oil channel 80 is formed. This is only the case in the upper planetary bolt 70 in Fig. Figure 3 illustrates this. The oil channel 80 forms an oil pocket 82 at one end region in a circumferential surface of the planetary pin 70. From this oil pocket 82, a radial sliding bearing between an inner circumference of the planetary pin 70 and an outer circumference of the planetary gear 68 is lubricated. Lubricating oil also escapes axially to the sides and lubricates axial sliding bearings between the facing end faces of the planetary gear 68 and the planet carrier 64.

[0031] In Fig. Figure 4 shows the oil channel 80 purely as an example without insulation. The planetary bolt 70 can transfer heat to the lubricating oil there unhindered, thus reducing its viscosity.

[0032] In Fig. Figure 5, however, shows an embodiment in which the lubrication system has insulation for the oil channel 80 in the planetary bolt 70. In the embodiment shown, the insulation has a first insulating element 84, which extends axially to the center of the planetary bolt 70. Furthermore, the insulation has a second insulating element 86, which extends radially from the first section to the oil pocket 82. The corresponding through-openings in the planetary bolt 70 differ from those in the example of Fig. 4 a larger diameter. The two insulating elements 84, 86 are designed as pipe sections which have a radially inner oil-impermeable layer which limits the cross-section available for the flow of lubricating oil in the oil channel 80 to a diameter which corresponds to the example in Fig. 4 corresponds to the insulating elements 84, 86, which are arranged within the oil channel 80. Radially outside the oil-impermeable layer and radially inside a wall of the planetary bolt 70 that delimits the oil channel 80, a thermally insulating material is arranged. Here, the thermally insulating material is designed as polyurethane, an epoxy coating, or foam. The thermally insulating material has a lower heat transfer coefficient than the metallic planetary bolt 70. This reduces the heating of the lubricating oil as it flows through the planetary bolt 70 during operation, allowing the viscosity of the lubricating oil to be high upon reaching the sliding bearings. In other embodiments, the insulation is designed as a coating on the wall of the planetary bolt 70, which delimits the oil channel 80.

[0033] In one embodiment, an additional sealing element is provided, which surrounds the opening of the oil pocket 82. In one design, this sealing element is configured as insulation. In another embodiment, insulation is provided between this sealing element and a wall of the planetary bolt 70 that delimits the oil pocket 82.

[0034] Fig. Figure 6 shows a metallic oil guide element 90 of the gearbox, which is radially oriented from left to right in the plane of the image within the gearbox 22. Fig. The oil guide element 90 extends to the gearbox housing. The oil guide element 90 supplies lubricating oil to the oil channel 80 in the planetary pin 70. For this purpose, the oil guide element has an oil channel 92, which forms an oil pocket 94 on an end face facing the planet carrier 64. The oil pocket 94 has an opening towards the oil channel 80 in the planetary pin 70, through which lubricating oil can flow into the oil channel 80. An insulating element 96 is arranged in the radially extending portion of the oil channel 92, which is designed analogously to the insulating elements 84, 86 in the planetary pin 70. In another embodiment, the insulation is also designed as a coating. The opening of the oil pocket 94 is enclosed by a sealing element 98, which has a polyamide ring and forms a labyrinth seal.In operation, this prevents excessive lateral leakage of lubricating oil as it flows from the oil guide element 90 to the planetary bolts 70 of the planet carrier 64. In one embodiment, the sealing element 98 is designed as an insulating element. In another embodiment, insulation is provided between the sealing element 98 and a wall of the oil guide element 90 that defines the oil pocket 94.

[0035] Fig. Figure 7 shows a side view of the ring gear 66 of the planetary gear set 60 of the transmission 22. The ring gear 66 has an axially extending oil channel 100, which guides the lubricating oil to the oil guide element 90. An insulating element 102 is arranged in the oil channel 100, which in Fig. 8 can be seen. The insulating element 102 is designed analogously to the insulating element 84, 86 in the planetary bolt 70. In another embodiment, the insulation is also designed as a coating. Reference sign 10 wind turbines 12 Rotor 14 hub 16 Rotor shaft 18, 38 rolling bearings 20 gondolas 22 gearboxes 24 Generator 26 brake 28 Tower 30 network connection 40 rotor bearing housings 42 machine bed 50 oil sump 52 Pump 54 Oil coolers 56 Lubrication area 60 planetary gear set 62 Sun wheel 64 planetary carriers 66 Ring gear 68 planetary gear 70 planetary bolts 80 Oil channel 82 Oil bag 84 Insulating element 86 Insulating element 90 Oil guide element 92 Oil channel 94 Oil bag 96 Insulating element 98 Sealing element 100 oil channel 102 Insulating element

Claims

[1] Lubrication system for a gearbox of a drive train of a wind turbine (10), wherein the lubrication system is configured to lubricate a planetary gear set (60) of the gearbox (22), wherein the lubrication system comprises an oil cooler (54) and an oil channel (80, 92, 100) in a metallic component of the gearbox (22), wherein the lubrication system is configured to supply lubricating oil from the oil cooler (54) through the oil channel (80, 92, 100) to a lubrication area (56), wherein the lubrication system comprises insulation (84, 86, 96, 102) configured to thermally insulate the lubricating oil in the oil channel (80, 92, 100) at least partially from the metallic component, wherein the lubrication system is configured to lubricate a bearing for a planet gear (68) of the planetary gear set (60) as a lubrication area (56), wherein the bearing is configured as a radial The bearing is designed as a plain bearing, wherein the bearing has an oil pocket (82),which has an opening in the direction of the planet gear (68), the opening being enclosed by a sealing element, characterized by , that the insulation is formed by the sealing element (98). [2] Lubrication system for a gearbox of a drive train of a wind turbine (10), wherein the lubrication system is configured to lubricate a planetary gear set (60) of the gearbox (22), wherein the lubrication system comprises an oil cooler (54) and an oil channel (80, 92, 100) in a metallic component of the gearbox (22), wherein the lubrication system is configured to supply lubricating oil from the oil cooler (54) through the oil channel (80, 92, 100) to a lubrication area (56), wherein the lubrication system comprises insulation (84, 86, 96, 102) configured to thermally insulate the lubricating oil in the oil channel (80, 92, 100) at least partially from the metallic component, wherein the oil channel (92) forms an oil pocket (94) in the metallic element, which has an opening towards a further oil channel (80), wherein the opening is equipped with a The sealing element (98) is enclosed. characterized by , that the insulation is formed by the sealing element (98). [3] Lubrication system according to any one of the preceding claims, characterized by , that the insulation (84, 86, 96, 102) is arranged inside the oil channel. [4] Lubrication system according to any one of the preceding claims, characterized by , that the insulation (84, 86, 96, 102) is formed as a coating of the metallic component. [5] Lubrication system according to any one of the preceding claims, characterized by , that the metallic component is designed as one of the following components: - a gearbox housing of the gearbox (22); - a planet carrier (64) of the planet gear set (60); - a ring gear (66) of the planetary gear set (60); or - a planetary bolt (70). [6] Lubrication system according to any one of the preceding claims, characterized by , that the insulation (84, 86, 96, 102) is configured as one of the following: - as an epoxy coating; - as a polyurethane; - as fiber optics; - as a mineral wool; - as an artificial foam; - as a calcium silicate; or - as a highly porous solid. [7] Lubrication system according to any one of the preceding claims, characterized by that the insulation is arranged on the inside or outside of the sealing element (98). [8] Drive train of a wind turbine (10) comprising a gearbox (22) comprising a planetary gear set 60) and a lubrication system according to one of the preceding claims. [9] Wind turbine (10) with a drive train according to claim 8.

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