Drive assembly for a wind turbine
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-12
- Publication Date
- 2026-08-13
Smart Images
Figure EP2026050535_13082026_PF_FP_ABST
Abstract
Description
[0001] ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0002] Drive system for a wind turbine
[0003] Technical field
[0004] The present disclosure relates to a drive arrangement for a wind turbine. The present disclosure also relates to a drive train with such a drive arrangement and to a wind turbine with such a drive train.
[0005] State of the art
[0006] Wind turbines are known to convert wind energy into electricity. These turbines utilize a rotor designed to convert wind energy into mechanical energy, such as rotation with torque. This torque can then be fed into a drive train to be converted into electrical power, for example, by a generator. The drive train can have one or more shafts that rotate relative to a housing and / or other shafts. In some designs, the housing and shafts are sealed against lubricant leakage by sealing elements. Due to the relative rotation, the lifespan of these sealing elements can be short.
[0007] Description of the invention
[0008] A first aspect of the present disclosure relates to a drive arrangement for a wind turbine. The wind turbine can have a rotor and a drive train. The rotor can be configured to convert wind energy into rotational mechanical energy and introduce this into the drive train. The drive train can be configured to convert at least part of the introduced mechanical energy into electrical energy. The drive arrangement can be part of the drive train. The wind turbine can have a tower and a nacelle, which accommodates and supports at least parts of the drive train. The nacelle can be attached to an upper end of the tower. The nacelle can be ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0009] The drive train can be rotatably mounted on the tower. A lower end of the tower can be anchored to the ground. Alternatively, the lower end of the tower can be attached to an offshore wind turbine platform. The drive train can include a generator to convert wind energy into electrical energy. The rotor can, for example, be operatively connected to the generator via a rotor shaft of the drive train.
[0010] The rotor can have multiple rotor blades, for example, three rotor blades. The drivetrain can include a hub through which the rotor is coupled to the rotor shaft. The hub can be configured to adjust the pitch angle of the rotor blades. The drivetrain can include a bushing component. This bushing component can be configured to route power supply lines through the shaft to a component of the drivetrain, such as the hub. The power supply lines can be configured to supply the hub with energy, for example, to adjust the pitch angle. For example, in the case of electric pitch angle adjustment, the bushing component can route power lines and / or hydraulic lines to the hub in the case of hydraulic pitch angle adjustment. The bushing component can be stationary or rotatable with respect to a stationary component of the drivetrain.For example, the feedthrough component can rotate together with the rotor or hub and, if applicable, the rotor shaft, for example at the same speed as the rotor. The rotational speed of the rotor and, if applicable, the rotor shaft can, for example, be between 2 and 30 revolutions per minute (rpm) or between 5 and 15 revolutions per minute (rpm) during operation.
[0011] The drivetrain can include a gearbox arranged in a power flow between the rotor and the generator. The generator can be configured to utilize the rotation of the rotor shaft or the rotation of a gearbox output for power generation. The gearbox can include rotating elements, such as shafts and gears. For example, the gearbox can have an input shaft, one or more gear stages, and an output shaft. The gear stages can include one or more gear sets, such as a spur gear set or a planetary gear set, and optionally one or more [ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20]
[0012] The gearbox features transmission shafts. It can be designed to convert the rotational speed of the rotor shaft to another, for example, higher, speed for driving the generator. The rotational speed for driving the generator can, for example, be between 500 rpm and 3000 rpm, or between 900 rpm and 2000 rpm. The gearbox input can be mechanically connected to the rotor, and the gearbox output can be mechanically connected to the generator. The torque at the gearbox input can, for example, be between 500,000 Nm and 15,000,000 Nm, or between 3,000,000 Nm and 10,000,000 Nm. The gearbox can be designed to transmit power from the rotor shaft to the generator.
[0013] The drive assembly comprises a functional component and a shaft. The functional component is arranged coaxially with the shaft. In one embodiment, the functional component can extend at least partially inside the shaft.
[0014] At least one of the functional components and the shaft can, for example, be a rotatable shaft of the drivetrain. Examples of rotatable shafts include the rotor shaft, at least one transmission shaft, and a generator drive shaft. The functional component can be a component of the drivetrain or separate from it. The functional component can, for example, be configured as the bushing component described above. Alternatively or additionally, the functional component can be configured as an axle that does not transmit torque or as a shaft that does transmit torque. A relative rotation can exist between the functional component and the shaft in at least one operating state. For example, both the functional component and the shaft can rotate and have different rotational speeds in at least one operating state.In another example, the functional component can be stationary, and the shaft can rotate relative to it. The functional component and the shaft can be arranged coaxially about a common central axis. At least one of the functional component and the shaft can be designed as a hollow shaft in at least one section. In one example, the shaft can be designed as a continuous hollow shaft. In such an example, the functional component can extend completely through the shaft. (ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20.)
[0015] Depending on the embodiment, the functional component can be the feedthrough component described above. In one embodiment, the shaft can be a transmission shaft. In another embodiment, the shaft can be a sun gear shaft of a planetary gear set. For example, the functional component can rotate at 2 to 20 rpm, for instance, 5 to 10 rpm. Alternatively, the shaft can rotate at 200 to 1000 rpm, for example, 400 to 600 rpm, for instance, 500 rpm.
[0016] The drive assembly also includes a sealing arrangement. Furthermore, a gap is formed between the functional component and the shaft in a radial direction. This gap can, for example, be an annular volume. The gap can be designed, for example, by having an outer dimension, such as an outer diameter, of the functional component that is smaller in the radial direction than an inner diameter of the shaft by the desired thickness of the gap. The thickness of the gap in the radial direction can, for example, be between 0.001% and 1% of the diameter of the functional component at the axial height of the gap. The gap can be designed to allow relative rotation between the functional component and the shaft. Additionally, the gap can be designed to prevent contact between the functional component and the shaft, at least during normal operation.Furthermore, the gap can be designed to cause a pressure drop of any lubricant that has entered the gap. For this purpose, the gap can, for example, have the smallest possible radial extent and the largest possible axial extent. The axial length of the gap can be, for example, 0.5 to 100 times, or 5 to 25 times, the diameter of the functional component. In addition, the gap can incorporate structures to increase the pressure drop of the lubricant within it.
[0017] The sealing arrangement can be designed to prevent the escape of lubricant present in a drivetrain housing. The housing can be designed to accommodate and support at least parts of the drivetrain, for example, by allowing it to rotate. For example, at least one of the ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0018] The functional component and the shaft are mounted in the housing and extend from an area inside the housing to an area outside the housing. A lubricant may be present in the housing. In such a case, the sealing arrangement may be designed to prevent lubricant from escaping from the housing. The lubricant may be designed to lubricate and / or cool components of the drivetrain. The lubricant may, for example, be an oil and / or a grease. The lubricant may have a viscosity that, under normal operating conditions, allows the lubricant to penetrate the gap described above. The sealing arrangement may have a function to minimize lubricant penetration and / or a function to drain any lubricant that has penetrated the housing.
[0019] The sealing arrangement includes a droplet formation section. For example, the droplet formation section can be located on the functional component or the shaft. It is also possible to provide droplet formation sections on both the functional component and the shaft. For example, the droplet formation section can be located on a circumferential surface of the respective component. The droplet formation section is designed to cause the formation of droplets of lubricant present in the gap. For this purpose, the droplet formation section can have structures that promote the formation of lubricant droplets. For example, the droplet formation section can have at least one or more protrusions, depressions, surface structures, and / or chemical surface treatments. For example, the droplet formation section can have at least one depression.The depression can form a rounded or sharp trailing edge for lubricant flowing in the gap. Alternatively or additionally, the droplet formation section can have one or more projections. The projection can be designed to concentrate the lubricant present in the gap at a tip of the projection. The projections and / or depressions can, for example, have a round, angular, and / or pointed shape. The droplet formation section can extend at least partially in a circumferential direction of the functional component or the shaft. For example, the ZF Friedrichshafen AG file 304743 Friedrichshafen 2025-01-20.
[0020] The droplet formation section extends in a ring-shaped manner, either partially or completely, around the respective component. The droplet formation section can be designed such that, when the component on which it is located—namely, the functional component or the shaft—rotates, it causes the formation of lubricant droplets. Furthermore, the droplet formation section can be designed such that the rotation of the component causes the formed droplets to be ejected. Alternatively or additionally, the droplet formation section can be designed such that lubricant droplets are also formed when the component on which it is located is stationary, for example, due to the influence of gravity. Multiple droplet formation sections can be provided.If several droplet formation sections are provided, these can be identical or different.
[0021] The sealing assembly includes a drainage device designed to at least partially remove the formed droplets. The drainage device may comprise passive fluid guidance elements such as chambers and channels. Alternatively or additionally, the drainage device may include active fluid guidance elements such as further channels, a suction pump, a blower, and / or switching valves. The drainage device may be configured to at least partially capture and remove the droplets formed by the droplet formation section. This removal may, for example, include returning the droplets to the drive train housing and / or returning them to a lubrication circuit. If multiple droplet formation sections are provided, a drainage device may be configured to at least partially remove droplets formed by several of these sections.Alternatively or additionally, a separate drainage device can be provided for each droplet formation stage.
[0022] The drive arrangement of the first aspect, with its droplet formation section and drainage device, ensures that the lubricant that has penetrated and is present in the gap is removed by means of droplet formation. Thus, the drive arrangement of the first aspect represents a contactless [ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20]
[0023] A sealing function is provided. This eliminates the need for contact with sealing elements, which can have a short lifespan. Since there is no contact between the functional component and the shaft providing the sealing function, the sealing function is not subject to wear. Accordingly, the drive arrangement of the first aspect provides a maintenance-free sealing function with a very long service life.
[0024] In one embodiment, the drainage device includes a collection chamber for capturing lubricant that has dripped from the droplet-forming section. The collection chamber can, for example, be configured as an annular channel that extends at least partially around the component in which the droplet-forming section is located. The collection chamber can, for example, be located within the shaft. Alternatively or additionally, the collection chamber can be located in another component, such as a housing. The collection chamber can at least partially overlap the droplet-forming section in the axial direction. In one embodiment, both the droplet-forming section and the collection chamber are configured to extend around the entire circumference of the functional component.For example, if the droplet formation section is located on a radially outer circumferential surface of the functional component, the collection chamber can be located on a radially inner circumferential surface of the shaft. The drainage device can also include a drain channel for removing the collected lubricant from the collection chamber. If the collection chamber is located within the shaft, the drain channel can, for example, extend through the other shaft and to a circumferential surface radially opposite the collection chamber to remove the lubricant. For example, the drain channel can be configured to remove the collected lubricant from the shaft and return it to the housing or the lubrication circuit. Several drain channels can be identical or different in design.
[0025] In one embodiment, the droplet formation section is formed on a radially outer surface of the functional component. This allows the formed droplets to be dislodged from this surface in the event of rotation of the functional component. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0026] The droplets are ejected, which promotes droplet formation and removal. In the present embodiment, the collection chamber is formed on a radially inner surface of the shaft. This allows the ejected droplets to be effectively captured and removed.
[0027] In one embodiment, the shaft has several shaft sections that overlap each other in the radial direction. For example, the shaft can have coaxial shaft sections designed as nested hollow shafts. In another embodiment, the shaft can have several, for example, three, shaft sections. The multiple shaft sections can coil in an S-shape between two axial sides. For example, a first shaft section can extend from a first axial side of the shaft to a second axial side of the shaft. A second shaft section can be connected to the first shaft section on the second axial side and extend to the first axial side. An optional third shaft section can be connected to the second shaft section on the first axial side and extend axially to the second axial side.Such a shaft design can reduce the shaft's torsional stiffness. This can be desirable, for example, to meet requirements regarding operating vibrations in the drivetrain, such as by lowering the shaft's natural frequency. Further embodiments incorporate more than three shaft sections.
[0028] With such a shaft design, it may be necessary to drain the lubricant from the collection chamber, which is formed on the radially inner surface of the shaft, namely the radially inner surface of a radially innermost shaft section, through the shaft sections. For this purpose, in the present embodiment, a further collection chamber of the sealing arrangement is formed on a radially inner side of each non-radially innermost shaft section. The further collection chamber can be identical to the collection chamber or different from it. Furthermore, each non-radially innermost shaft section can have a further drain channel that extends through the respective shaft section to drain the oil from the further collection chamber. The present embodiment [ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20]
[0029] It allows the flow to pass through the wave, even if the wave has several overlapping sections.
[0030] In one embodiment, the sealing arrangement comprises a further droplet-forming section and a connecting channel. The further droplet-forming section is formed on a radially outer side of each non-radially outermost shaft section. The connecting channel can, for example, extend through the respective shaft section. The further droplet-forming section and the collection chamber of the respective shaft section can be connected to the connecting channel. For example, the radially innermost shaft section can have the collection chamber, and the other shaft sections can have the further collection chamber. In both the case of the collection chamber and in the case of the further collection chamber, the respective collection chamber can be connected to the respective further droplet-forming section by a connecting channel. The radially outermost shaft section can optionally also have a further droplet-forming section.Alternatively or additionally, the radially outermost shaft section can be configured to discharge the lubricant captured by its wider collection chamber, for example, through a discharge channel. The present embodiment makes it possible to transfer lubricant captured by one of the shaft sections to the radially adjacent shaft section. In the case of the radially outermost shaft section, it is possible to discharge the captured lubricant from the shaft, for example, by transferring it to the housing.
[0031] In one embodiment, the sealing arrangement has an outer droplet-forming section, which is formed axially outside the gap on the functional component. The outer droplet-forming section can be configured identically to the droplet-forming section described above or differently. The outer droplet-forming section can be designed to allow lubricant to drip off and / or be flung out of the functional component before the lubricant enters the gap. This can improve the effectiveness of the non-contact sealing function. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0032] In one embodiment, several droplet-forming sections are arranged axially adjacent to one another. These can be the droplet-forming sections of the functional component and / or the shaft, the additional droplet-forming sections of the shaft sections, and / or the outermost droplet-forming sections. In some cases, a single droplet-forming section cannot allow all of the lubricant present on the droplet-forming section to drip off, for example, because the lubricant flow velocity is too high or its viscosity is unsuitable. Then, some of the lubricant may remain in the gap or near the droplet-forming section, or it may pass through the droplet-forming section. In such a case, providing several droplet-forming sections axially adjacent to one another improves the effectiveness of the sealing function.
[0033] In one embodiment, the droplet formation section is formed integrally with the functional component. For example, the droplet formation section can be formed by machining within the functional component. In an alternative embodiment, the droplet formation section can be formed on a separate component that is joined to the functional component. For example, the droplet formation section can be formed within a sleeve that is joined to the functional component. The foregoing embodiments can refer independently to the droplet formation section, the further droplet formation section, and / or the outer droplet formation section.
[0034] In one embodiment, the droplet formation section has a depression formed in a circumferential surface of the functional component or the shaft. As described above, the circumferential surface can be a radially outer or a radially inner circumferential surface. The depression can be configured in the manner described above to promote droplet formation. The depression can have a round, angular, or pointed shape, or a combination thereof. In one embodiment, the ZF Friedrichshafen AG file 304743 Friedrichshafen 2025-01-20
[0035] The droplet formation section may have several depressions that partially overlap. In a further embodiment, the droplet formation section may have several depressions that do not overlap.
[0036] In one embodiment, the droplet-forming section has a projection formed within the depression. The projection can, for example, be located on the bottom of the depression and protrude from it. The projection can be round, angular, or pointed, or a combination thereof. The droplet-forming section can also have several projections, for example, two, arranged within the depression and axially spaced apart. The multiple projections can be identical or different in shape. In an alternative embodiment, the droplet-forming section can have one or more projections without a corresponding depression.
[0037] In one embodiment, the shaft is configured to mechanically connect a gearbox of the wind turbine to a generator of the wind turbine. In another embodiment, the functional component is designed as a feedthrough component for routing power supply lines for a component of the wind turbine's drive train.
[0038] A second aspect of the present disclosure relates to a drive train with a drive arrangement according to the first aspect. The drive train can be configured as described above. Respective advantages and further features can be found in the description of the first aspect, whereby embodiments of the first aspect also constitute embodiments of the second aspect and vice versa.
[0039] A third aspect of the present disclosure relates to a wind turbine with a drive train according to the second aspect. The wind turbine can, for example, be configured for electricity generation. The respective advantages and further features 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. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0040] Brief description of the characters
[0041] Figure 1 schematically illustrates a wind turbine.
[0042] Figure 2 shows a schematic sectional view of a drive arrangement according to one embodiment.
[0043] Figure 3 shows a schematic sectional view of a sealing arrangement of the drive arrangement of Figure 2.
[0044] Figure 4 schematically shows an outer droplet formation section of the drive arrangement of Figure 2.
[0045] Figure 5 shows a schematic sectional view of a drive arrangement according to one embodiment.
[0046] Figure 6 schematically shows different variants of cross-sections for forming a droplet formation section.
[0047] Figure 7 schematically shows different variants of cross-sections for forming a capture chamber.
[0048] Detailed description of embodiments
[0049] Figure 1 schematically illustrates a horizontally mounted wind turbine 1. The wind turbine 1 has a nacelle 3, which is attached to the upper end of a tower 2. A lower end of the tower 2 is anchored to a ground 5. The nacelle 3 houses a drive train 10, which includes a rotor shaft 11, a gearbox 12, a generator 13, auxiliary components 14, and a hub 15. A rotor 4 of the wind turbine 1 is mechanically connected to the generator 13 via the hub 15, the rotor shaft 11, and the gearbox 12. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0050] Figure 2 shows a schematic sectional view of a drive arrangement according to one embodiment. The drive arrangement comprises a functional component 20, a shaft 30, and a sealing arrangement 40. The functional component 20 and the shaft 30 are arranged coaxially about a common central axis 90.
[0051] In this case, the functional component 20 is a through-drive component of the drive train 10, designed as a hollow shaft rotating with the hub 15. The shaft 30 is a transmission shaft of the gearbox 12, specifically a sun gear shaft. The shaft 30 has three shaft sections 31, 32, 33, which extend from a drive 34, designed as a sun gear, in an S-shape between a first axial side 91 and a second axial side 92. The shaft 30 is rotatably mounted in a stationary component 16 by two bearings 35. The stationary component 16 is a housing of the gearbox 12. A lubricant for lubricating and cooling drive train components is present in the housing 16. A gap 22 is formed between the functional component 20 and the shaft 30 in a radial direction 94.The sealing arrangement 40 is designed to prevent the lubricant in the housing 16 from passing from the first axial side 91, which corresponds to an interior of the gearbox 12, to the second axial side 92, which corresponds to an exterior of the gearbox 12.
[0052] Figure 3 shows details of the sealing arrangement 40 from Figure 2 and corresponds to a section 100 in Figure 2. The sealing arrangement 40 has a droplet-forming section 42 and a drainage device 44. In this case, the sealing arrangement 40 has two assemblies 42, 44, each of which has a droplet-forming section 42 and a drainage device 44 and is arranged axially adjacent to one another. For clarity, only the arrangement 42, 44 on the first axial side 91, namely the left side in Figure 3, is described in detail here. The arrangement 42, 44 on the second axial side 92, namely the right side in Figure 4, is identical in design and is only axially offset in the direction of the second axial side 92.
[0053] The droplet formation section 42 is formed on a radially outer circumferential surface of the functional component 20. A gap 22 is located between the ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0054] A gap 22 is formed between the functional component 20 and the shaft 30, specifically between the radially outer circumferential surface of the functional component 20 and the radially inner surface of a first shaft section 31. The gap 22 has a sufficient radial thickness so that the shaft 30 does not contact the functional component 22, at least under normal operating loads. The droplet-forming section 42 adjoins the second axial side 92 of the gap 22. The droplet-forming section 42 is designed as a recess with three projections. Furthermore, the droplet-forming section 42 is formed integrally within the functional component 20. Additionally, the droplet-forming section 42 extends around the entire functional component 20. Opposite the droplet-forming section 42, a collection chamber 46 is formed, in this case as a circumferential groove on the radially inner circumferential surface of the first shaft section 31.
[0055] In the present embodiment, the collection chamber 46 is connected via a connecting channel 54 to a further droplet-forming section 52 of the first shaft section 31. The connecting channel 54 extends radially through the first shaft section 31 and also serves as part of a drainage channel 48. The further droplet-forming section 52 of the first shaft section 31 is designed as a recess with a projection. Opposite the further droplet-forming section 52 of the first shaft section 31, a further collection chamber 50 is formed in a second shaft section 32. In this embodiment, the further collection chamber 50 is designed as a circumferential groove in a radially inner circumferential surface of the second shaft section 32. The further collection chamber 50 of the second shaft section 32 is connected via a connecting channel 54 to a further droplet-forming section 52.The further droplet formation section 52 of the second shaft section 32 is designed as a depression with a projection. The connecting channel 54 of the second shaft section 32 also serves as part of the drain channel 48. Opposite the further droplet formation section 52 of the second shaft section 32, a further collection chamber 50 is formed in a third shaft section 33. The further collection chamber 50 is connected to a channel extending radially through the third shaft section 33, which forms part of the drain channel 48. The drain channel 48 opens into a radially outer circumferential surface of the third shaft section 33.
[0056] Wave section 33. Thus, the further droplet formation sections 52, the capture chambers 46, 50 and the drainage channel 48, which also includes the connecting channels 54, form the drainage device 44, which is assigned to the droplet formation section 42.
[0057] A lubricant can be present in the gap 22 and flow towards the second axial side 92, for example, under the influence of rotation of the shaft 30 during operation. The lubricant, which reaches the droplet formation section 42 from the gap 22, forms droplets and can drip from the functional component 20. In the present embodiment, the functional component 20 rotates, so that the formed droplets are ejected. Such a lubricant flow 80 from the gap 22 and outwards is schematically represented by an arrow. In a further embodiment (not shown), the functional component 20 is stationary, so that the lubricant drips off only under the influence of gravity.In the present embodiment, the lubricant dripping from the functional component 20 is captured by the collection chamber 46 of the first shaft section 31 and guided via the connecting channel 54 to the further droplet formation section 52 of the first shaft section 31. There, this lubricant, together with a lubricant flow 82, can drip out of a small gap between the shaft sections 31 and 32, or in this case, be ejected. Similarly, the lubricant coming from the first shaft section 31 is captured by the further collection chamber 50 of the second shaft section 32, guided via the connecting channel 54 to the further droplet formation section 52 of the second shaft section 32, and there, together with a further lubricant flow 84, drip out, or in this case, be ejected.The lubricant coming from the second shaft section 32 is captured by the further capture chamber 50 and discharged via the drain channel 48, which is shown here as an arrow 86.
[0058] Details regarding the removal process are described below with reference to Figure 5.
[0059] Due to the above-described design, the sealing arrangement 40 of the drive arrangement of the present embodiment is able to at least partially drain the lubricant present in the gap 22 and prevent it from penetrating. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0060] to prevent the lubricant from flowing towards the second axial side 92. This provides a highly effective non-contact sealing function. If some of the lubricant present in the gap 22 is not drained off by the arrangement 42, 44 located on the first axial side 91 and therefore continues to penetrate towards the second axial side 92, it can optionally be at least partially drained off by the further arrangement 42, 44 on the second axial side 92. This can improve the effectiveness of the non-contact sealing function.
[0061] To further improve the effectiveness of the sealing function, an optional outer droplet-forming section 56 is provided on the functional component 20 in the present embodiment shown in Figure 2. Figure 4 schematically shows enlarged sections of the drive assembly from Figure 2 to better illustrate the outer droplet-forming section 56. The upper part of Figure 4 shows the drive assembly from Figure 2. A region A in this representation is shown enlarged on the left side of Figure 4. As can be clearly seen in this enlarged view of region A, three outer droplet-forming sections 56 are formed on the first axial side 91, axially adjacent to the gap 22. One of the three outer droplet-forming sections 56 is shown as an enlarged section B at the bottom of Figure 4.The outer droplet-forming sections 56 are configured differently from the droplet-forming sections 42 and the other droplet-forming sections 52. Each of the outer droplet-forming sections 56 is designed as a round depression with an angular projection. The outer droplet-forming sections 56 allow lubricant to drip off the functional component 20 before it can penetrate the gap 22. Consequently, less lubricant reaches the gap 22 than in a drive arrangement without outer droplet-forming sections 56. This further improves the effectiveness of the contactless sealing function.
[0062] Figure 5 shows a drive arrangement according to an embodiment of the present disclosure. The drive arrangement of Figure 5 is the same as the drive arrangement of Figure 2, except for the differences described below. Furthermore, Figure 5 shows details of the discharge of the fluid carried away through the discharge channel 48. ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20
[0063] The lubricant 86 is also applicable to the embodiment of Figure 2. While in the embodiment of Figure 2 the droplet-forming sections 42 are formed integrally in the functional component 20, in the present embodiment of Figure 5 the droplet-forming sections 42 are formed in a sleeve 24. The sleeve 24 is formed separately from the functional component 20 and joined to it, in this case by an interference fit. Further features of the embodiment of Figure 5 can be found in the description of the embodiment of Figure 2. On the upper side of the shaft 30 in Figure 5, which is shown enlarged in area B, the lubricant is flung out through the drain channel 48 due to the rotation of the shaft 30 and collected in a discharge chamber 58. In this case, the discharge chamber 58 is formed in an annular shape in a further shaft section 37 of the shaft 30 and surrounds the shaft 30.On the lower side of the shaft 30 shown in Figure 5, which is enlarged in area A, a discharge channel 59 is formed at the lower end of the discharge chamber 58 in the further shaft section 37 of the shaft 30. The lubricant can be discharged through the discharge channel 59 to the housing 16 and thus removed from the drive assembly.
[0064] Figure 6 shows various cross-sectional designs for forming droplet formation sections. These designs are applicable to droplet formation section 42, the secondary droplet formation section 52, and the outermost droplet formation section 56. Figure 6 illustrates seven designs A, B, C, D, E, and F, but further variations and combinations are possible. In a basic form of designs A, C, and G, the droplet formation section has only a depression 60. In designs A and C, the depression 60 is rounded, with the depression 60 in design A having a more pointed shape than the depression 60 in design C. In contrast, the depression 60 in design G has an angular shape. In further designs, a projection 62 can be formed in the depression 60, as shown in designs B, E, and F.In variants B and E, a round projection 62 is formed in a round depression 60, whereby the projection 62 of variant B has a significantly smaller height relative to the depth of the depression 60 than the projection 62 of variant E. In variant F, both the projection 62 and the depression 60 are... [ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20.]
[0065] The projections are angular in shape. In variant D, two round projections 62, 64 are formed in a round recess 60. The projections 62, 64 have the same height and partially overlap in the axial direction. In other variants (not shown), projections are formed in varying numbers. In other variants (not shown), angular projections are combined with round recesses and vice versa. In other variants (not shown), projections are formed without corresponding recesses. In all cases, the droplet formation section is designed to promote the formation of lubricant droplets.
[0066] Figure 7 shows variations of cross-sections for forming collection chambers. These variations are applicable to collection chamber 46 and the further collection chamber 50. In variation A, the collection chamber is shaped like a circular segment. In variation B, the collection chamber is essentially trapezoidal. In variation C, the collection chamber is rectangular, specifically cuboid. Further variations, not shown, include other shapes, optionally with rounded edges. In all cases, the collection chamber is designed to capture any dripped lubricant. ZF Friedrichshafen AG File 304743
[0067] Friedrichshafen 2025-01-20
[0068] Reference mark
[0069] 1 wind turbine
[0070] 2 Tower
[0071] 3 gondolas
[0072] 4 Rotor
[0073] 5 Floor
[0074] 10 Drivetrain
[0075] 11 Rotor shaft
[0076] 12 gearboxes
[0077] 13 Generator
[0078] 14 auxiliary units
[0079] 15 hub
[0080] 16 stationary component
[0081] 20 Functional component
[0082] 22 columns
[0083] 24 sleeve
[0084] 30 wave
[0085] 31, 32, 33, 37 Wave section
[0086] 34 Drive
[0087] 35 storage
[0088] 40 Sealing arrangement
[0089] 42 Droplet formation section
[0090] 44 Drainage device
[0091] 46 Capture chamber
[0092] 48 Drainage channel
[0093] 50 more capture chambers
[0094] 52 further droplet formation section 54 connecting channel
[0095] 56 outer droplet formation section 58 bowel chamber
[0096] 59 Drainage channel
[0097] 60 In-depth study ZF Friedrichshafen AG File 304743
[0098] Friedrichshafen 2025-01-20
[0099] 62, 64 lead
[0100] 80, 82, 84 Lubricant flow
[0101] 86 Discharged lubricant 88 Returned lubricant 90 Central axis
[0102] 91, 92 axial side
[0103] 94 radial direction
[0104] 100 excerpts
Claims
ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20 Patent claims 1. Drive arrangement for a wind turbine (1) comprising a functional component (20), a shaft (30) and a sealing arrangement (40), wherein the functional component (20) is arranged coaxially to the shaft (30) and a gap (22) is formed between the functional component (20) and the shaft (30) in a radial direction (94), and wherein the sealing arrangement (40) comprises a droplet formation section (42; 56) which is configured to cause the formation of droplets of a lubricant present in the gap (22), and a drainage device (44) which is configured to at least partially drain the formed droplets.
2. Drive arrangement according to claim 1, characterized in that the drainage device (44) has a collection chamber (46) for capturing lubricant which has dripped from the droplet formation section (42) and a drainage channel (48) for removing the captured lubricant from the collection chamber (46).
3. Drive arrangement according to claim 2, characterized in that the droplet formation section (42) is formed on a radially outer surface of the functional component (20) and the capture chamber (46) is formed on a radially inner surface of the shaft (30).
4. Drive arrangement according to claim 3, characterized in that the shaft has several shaft sections (31 , 32, 33) which overlap each other in the radial direction (94), wherein a further trap chamber (50) of the sealing arrangement (40) is formed on a radially inner side of each non-radially innermost shaft section (32, 33).
5. Drive arrangement according to claim 4, characterized in that the sealing arrangement (40) has a further droplet formation section (52) and a connecting channel (54), wherein the further droplet formation section (52) is located on a radially outer side of each non-radially outermost shaft section (31, 32). ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20 is formed and the further droplet formation section (52) and the capture chamber (46; 50) of the respective wave section (31; 32) are connected by the connecting channel (54).
6. Drive arrangement according to one of the preceding claims, characterized in that the sealing arrangement (40) has an outer droplet formation section (56) which is formed axially outside the gap (22) on the functional component (20).
7. Drive arrangement according to one of the preceding claims, characterized in that several droplet formation sections (42; 52; 56) are arranged axially next to each other.
8. Drive arrangement according to one of the preceding claims, characterized in that the droplet formation section (42; 52; 56) is formed integrally with the functional component (20).
9. Drive arrangement according to one of the preceding claims, characterized in that the droplet formation section (42; 52; 56) has a recess (60) which is formed in a circumferential surface of the functional component (20) or the shaft (30).
10. Drive arrangement according to claim 9, characterized in that the droplet formation section (42; 52; 56) has a projection (62; 64) which is formed in the recess (60).
11. Drive arrangement according to one of the preceding claims, characterized in that the shaft (30) is configured to mechanically connect a gearbox (12) of the wind turbine (1) with a generator (13) of the wind turbine (1).
12. Drive arrangement according to one of the preceding claims, characterized in that the functional component (20) is a ZF Friedrichshafen AG File 304743 Friedrichshafen 2025-01-20 The feedthrough component is designed for routing energy supply lines for a component (15) of a drive train (10) of the wind turbine (1).
13. Drive train (10) comprising a drive arrangement according to one of the preceding claims.
14. Wind turbine (1) with a drive train (10) according to claim 13.