Power train of wind turbine with lubrication system and wind turbine comprising lubrication system

Abstract

The invention relates to a drive train (6) of a wind turbine (1) and to a wind turbine having such a drive train, the drive train (6) comprising at least a gearbox (7), a generator (8) and a lubrication system (10). The lubrication system (10) comprises at least a pump unit (16), a main filter system (17), a heat exchanger (19) and a distribution unit (21). The secondary filter system (20) is arranged upstream with respect to the distribution unit (21) and downstream with respect to the heat exchanger (19). The first filter system has at least one first filter (17) with a first filtration range, and the second filter system (20) has at least one second filter with a second filtration range. The first filtration range is different from the second filtration range.

Description

Technical Field

[0001] This invention relates to a drive system for a wind turbine, comprising a low-speed interface configured to be connected to the rotor of the wind turbine, a generator having a generator output, and a lubrication system arranged relative to the low-speed interface or the generator. The lubrication system is configured to circulate a lubricating medium through a piping system through at least the low-speed interface or the generator. The lubrication system includes at least a pump unit, a main filter system, a heat exchanger unit, and a distribution unit.

[0002] The present invention also relates to a wind turbine including a lubrication system. Background Technology

[0003] It is well known that debris contamination in the lubricating oil used in wind turbine gearboxes can cause serious and progressive damage or failure of gearbox components. Therefore, the lubricating oil from the gearbox is circulated through a filtration system before being distributed back into the gearbox. The filtration system is designed to remove debris and other unwanted particles from the lubricating oil.

[0004] WO 2010 / 052271 A1 discloses a lubrication system for a wind turbine, wherein lubricating oil is pumped out of the gearbox and pumped through a filter and a heat exchanger before entering the gearbox. The heat exchanger is arranged upstream of the filter, wherein a variable flow valve can be used to bypass the heat exchanger. However, any debris or other particles from the heat exchanger or bypass valve are directed directly back into the gearbox.

[0005] EP 3574212 B1 discloses a drivetrain for a wind turbine, wherein a lubrication system is arranged relative to the drivetrain. During operation, lubricating oil is pumped by two main pumps through return pipes to two filters and further to a heat exchanger. The lubricating oil is guided from the heat exchanger to a manifold distribution unit before being redirected back into the drivetrain. However, any debris or other particles from the heat exchanger are directly guided back into the gearbox.

[0006] EP 2756189 B1 discloses a lubrication system for a gearbox in a wind turbine, wherein a pump pumps lubricating oil from the gearbox outlet to a filter assembly, and further pumps the lubricating oil through an oil cooler before it enters the gearbox inlet. The filter assembly includes fine-inlet filters and other filters interconnected in parallel to control pressure drop. However, this solution requires a balance between gear smoothness and lubricating oil viscosity.

[0007] CN 217736231 U discloses a lubrication system for a gearbox in a wind turbine, wherein a mechanical pump and an electric pump are arranged in parallel to pump lubricating oil from the gearbox to a filter system and through an air cooler. The lubricating oil from the air cooler is guided back into the gearbox via a distribution valve block. The filter system includes a fine filter and a coarse filter. However, any debris or other particles from the air cooler are directly guided back into the gearbox.

[0008] Other lubrication systems for wind turbine gearboxes, such as those disclosed in US 2013 / 00288843 A1, include an oil tank connected to the gearbox via a lubrication circuit. The lubrication circuit includes a pump and a filter system disposed downstream of the pump, wherein lubricating oil is pumped from the tank through the filter system and into the corresponding part of the gearbox. A heat exchanger in the lubrication circuit is used to control the viscosity and temperature of the lubricating oil pumped into the gearbox. However, the oil tank requires periodic cleaning because debris from the gearbox accumulates in the tank. Furthermore, over time, debris or other particles may deposit in the pump or heat exchanger, thereby reducing their efficiency.

[0009] Therefore, an improved lubrication system is needed for the drivetrain of wind turbines.

[0010] Purpose of the invention One object of the present invention is to solve the above-mentioned problems existing in the prior art, or at least to provide an alternative solution.

[0011] One object of the present invention is to provide a drivetrain and wind turbine that reduces the risk of debris from the heat exchanger entering the gearbox.

[0012] One object of the present invention is to provide a drivetrain and wind turbine that reduces the risk of debris entering the gearbox during maintenance of the filter system. Summary of the Invention

[0013] One object of the present invention is achieved by the drive system of the wind turbine according to claim 1, the drive system comprising: - A low-speed interface configured to connect to the rotor of a wind turbine and provide mechanical torque directly or indirectly to a generator; - A generator having a generator output section, wherein the generator includes a generator rotor, the generator rotor being rotatably arranged relative to the generator stator and configured to interact with the generator stator via at least one magnetic field; and - A lubrication system, arranged relative to at least a low-speed interface or generator, configured to circulate a lubricating medium through the low-speed interface or generator via a piping system, and comprising at least one pump unit, at least one main filter system, at least one heat exchanger unit, and optionally at least one distribution unit. Its features are, - The lubrication system also includes at least one secondary filter system, wherein the secondary filter system is arranged downstream of the heat exchanger unit.

[0014] This provides additional protection for rotating parts and bearings in the transmission system from contamination by lubrication system components located upstream of the distribution unit. The invention incorporates an additional filter system between the distribution unit and the oil conditioning components. Furthermore, contaminants from the transmission system are filtered out downstream of one or more oil conditioning components via the main filter system.

[0015] Lubrication systems can include various oil regulating components such as heat exchangers and pumps. Heat exchangers can use a second medium to cool or heat the lubricating medium, wherein the second medium can be separate from the lubricating medium. The second medium can be a liquid such as water or a gas such as air. This allows for isolated flow of the lubricating medium and the second medium within the heat exchanger.

[0016] The pump can be driven by a motor connected to an energy source. The motor can be electrically, hydraulically, or pneumatically driven. The motor can be powered by a separate energy source or by the mechanical or electrical power output of a drivetrain. This reduces the need for a separate drive unit in the wind turbine, thereby lowering costs and reducing weight.

[0017] The main filter system is located upstream of the heat exchanger. Preferably, the main filter can be located downstream of the low-speed interface or the generator's lubrication outlet and upstream of the pump. Alternatively, the main filter system can be located between the pump and the heat exchanger. This allows most contaminants from the drivetrain to be filtered out as the lubricating medium leaves the drivetrain components. This also eliminates or at least reduces the maintenance requirements for the secondary filter system.

[0018] Furthermore, the secondary filter system is arranged downstream of the heat exchanger. Preferably, the secondary filter system may be arranged downstream of the heat exchanger and upstream of the distribution unit or lubrication inlet of the low-speed interface or generator. Alternatively, the secondary filter system may be arranged between components of the distribution unit or between the distribution unit and the lubrication inlet. This provides greater protection for the respective drivetrain components from contamination from lubrication system components, as these contaminants can be filtered out when the lubricating medium enters the drivetrain components. This eliminates the need for a separate filter for each lubrication inlet of each drivetrain component, thereby reducing the total number of filters required.

[0019] The distribution unit can be a common manifold connected to all drivetrain components, or a separate manifold connected to the lubrication input of each dedicated drivetrain component. The distribution unit may also include one or more valves configured to distribute lubricating medium to the drivetrain components. This allows for the use of a common lubrication circuit for the drivetrain components or a dedicated lubrication circuit for each drivetrain component.

[0020] Alternatively, the distribution unit can be omitted, and the lubricating medium can be directly distributed to the transmission components via a piping system.

[0021] Optionally, the lubricating medium for each transmission component can flow into and out of a shared housing or chamber. This allows for the use of a shared lubrication system.

[0022] In one embodiment, the primary filter system includes at least one primary filter having a first filtration rate, and the secondary filter system includes at least one secondary filter having a second filtration rate, wherein the first filtration rate is equal to the second filtration rate.

[0023] One or more primary filters are arranged in parallel and / or in series within a primary filter system, wherein the primary filters together define the combined primary filtration rate. Similarly, one or more secondary filters are arranged in parallel and / or in series within a secondary filter system, wherein the secondary filters together define the combined secondary filtration rate.

[0024] A dual filtration system can be formed by selecting filters from both the primary and secondary filter systems. This reduces the risk of debris and other particles from the heat exchanger entering the drivetrain components.

[0025] In this embodiment, the primary filter system and the secondary filter system may have the same filter configuration and / or the same filtration rate. For example, the primary filter system and the secondary filter system may have the same filtration rate but different filter configurations, or the primary filter system and the secondary filter system may have the same filter configuration but different filtration rates. Alternatively, the primary filter system and the secondary filter system may have the same filter configuration and the same filtration rate.

[0026] In one embodiment, the primary filter system includes at least one primary filter having a first filtration rate, and the secondary filter system includes at least one secondary filter having a second filtration rate, wherein the first filtration rate is different from the second filtration rate.

[0027] The filters in the primary filter system and the secondary filter system can be selected to form an alternating dual filtration system. This also reduces the risk of debris and other particles from the heat exchanger entering the drivetrain components.

[0028] In this embodiment, the primary filter system and the secondary filter system may have different filter configurations and / or different filtration rates. For example, the primary filter system and the secondary filter system may have different filtration rates but the same filter configuration. Alternatively, the primary filter system and the secondary filter system may have different filtration rates and different filter configurations.

[0029] The filtration size of the corresponding primary and / or secondary filters can be selected based on the temperature range, viscosity, and type of the lubricating medium used, as well as the particle size of the contaminants. The lubricating medium can be oil or other types of lubricants, preferably synthetic oils or lubricants.

[0030] In one embodiment, one of the primary filter and the secondary filter is a finer filter, while the other of the primary filter and the secondary filter is a coarse filter.

[0031] The types of primary and secondary filters can be selected to remove both fine and coarse debris. For example, the primary filter can be configured to remove coarse debris, while the secondary filter can be configured to remove fine debris. Alternatively, one or both of the primary and secondary filter systems can be configured to remove both fine and coarse debris. This increases the overall filtration range of the lubrication system, thereby reducing the risk of failure in drivetrain components and increasing the intervals between lubrication media replacements.

[0032] In one embodiment, the ratio of the second filtration size of the secondary filter system to the first filtration size of the primary filter system is between 2 and 50.

[0033] The optimal ratio for filtering out unwanted debris and other particles can be selected based on the transmission system configuration and the type of lubricating medium used. The primary filters (each main filter) can have a first filtration size with a predetermined efficiency. Furthermore, the secondary filters (each secondary filter) can have a second filtration size with a predetermined efficiency. The applicant has discovered that optimal filtration can be achieved when the ratio between the second filtration size and the first filtration size is selected between 2 and 50.

[0034] In one embodiment, the first filter size is selected from the range of 2 μm to 500 μm.

[0035] Preferably, the first filter size can be selected such that most unwanted particles or debris are filtered out by the main filter. Preferably, the main filter can be selected to have a first filter size between 2 μm and 500 μm. This allows most debris and other unwanted particles from the drivetrain components to be filtered out before the lubricating medium enters the heat exchanger.

[0036] In one embodiment, the second filter size is selected from the range of 10 μm to 2500 μm.

[0037] Preferably, the second filtration size of the secondary filter can be selected to at least filter out debris and other unwanted particles that were not removed in the primary filter. The heat exchanger can be relatively long and can be fitted with small flow channels that readily release debris over time, for example, caused by vibration. Therefore, the second filtration size of the secondary filter can be further selected to filter out debris released from the heat exchanger. Thus, the secondary filter can be selected to have a second filtration size between 10 μm and 2500 μm.

[0038] In one embodiment, the transmission system further includes a gearbox having at least one gear stage, wherein the gearbox includes a gearbox input configured to transmit torque to at least one gear stage and a gearbox output configured to be connected to a generator rotor.

[0039] The drivetrain may also include a gearbox with a gearbox input configured to connect to the rotor of the wind turbine, such as its hub. The gearbox also has a gearbox output configured to connect to the generator rotor. The gearbox may be positioned between the rotor and the generator rotor. The gearbox may include a single gear stage or multiple gear stages. This allows the low rotational speed of the rotor to be converted to the medium or high rotational speed of the generator.

[0040] Alternatively, the gearbox can be directly connected to the rotor via a low-speed interface.

[0041] In one embodiment, the low-speed interface includes a main bearing assembly having a main bearing housing, a spindle, and at least one main bearing disposed between the spindle and the main bearing housing.

[0042] The gearbox or generator rotor can be indirectly connected to the rotor via a main bearing assembly. The main bearing assembly may include a main shaft configured to connect to the rotor at one end and to the gearbox input at the other end. At least one main bearing may be arranged relative to the main shaft for support. Preferably, a front main bearing and a rear main bearing may be arranged relative to the main shaft. The rear main bearing may be a shared bearing between the main bearing assembly and the first stage of the gearbox.

[0043] The main bearing assembly may also include a main bearing housing extending around the main shaft. The main bearing housing may be connected to the gearbox housing at the rear end. The main bearing housing may serve as the seat for the main bearings (each main bearing).

[0044] In one embodiment, the drivetrain is an integrated drivetrain or a direct-drive drivetrain.

[0045] This invention allows for the construction of an integrated drivetrain, wherein the generator, gearbox, and / or main bearing assembly are integrated to form a compact drivetrain. A lubrication system can be connected to this integrated drivetrain and configured to provide lubrication to bearings, gear components, and other rotating parts.

[0046] Furthermore, the present invention also allows the transmission system to be configured as a direct-drive transmission system, wherein the gearbox and / or main bearing assembly are omitted, and the generator rotor is connected to the rotor. A lubrication system can be connected to this direct-drive transmission system and configured to provide lubrication to the bearings and other rotating parts.

[0047] One object of the present invention is achieved by a wind turbine according to claim 11, the wind turbine comprising a wind turbine tower, a nacelle disposed on top of the wind turbine tower, and a rotor comprising a hub and at least one wind turbine blade, wherein the rotor is disposed relative to the nacelle and mechanically connected to the wind turbine's drive system, characterized in that the drive system is constructed as described above.

[0048] This provides an improved lubrication system for the drivetrain of wind turbines compared to conventional lubrication systems. The invention provides additional protection for drivetrain components from contamination from all lubrication system components located upstream of the distribution unit. The invention also provides protection during main filter maintenance—which can lead to debris ingress, as debris may be introduced when the main filter element is removed.

[0049] Preferably, the secondary filter can be selected to have a larger filter size than the primary filter. This allows most debris and other unwanted particles to be filtered out by the primary filter, while the secondary filter can filter out debris introduced during maintenance of the primary filter and heat exchanger. Attached Figure Description

[0050] The invention has been described by way of example only and with reference to the accompanying drawings, in which: Figure 1 An exemplary embodiment of a wind turbine is shown; Figure 2 A first embodiment of the drivetrain for a wind turbine is shown; Figure 3 A second embodiment of the drivetrain for a wind turbine is shown; Figure 4 An exemplary embodiment of the main bearing assembly is shown; and Figure 5 An exemplary embodiment of the lubrication system according to the present invention is shown.

[0051] The accompanying drawings will be described one by one below, and different parts and locations seen in the drawings will be labeled with the same reference numerals in different drawings. Not all parts and locations indicated in a particular drawing are necessarily the same as those in that drawing. Figure 1 Let's begin the discussion. Detailed Implementation

[0052] Figure 1 An exemplary embodiment of a wind turbine 1 is shown, the wind turbine 1 including a wind turbine tower 2, a nacelle 3 disposed on top of the wind turbine tower 2, and a rotor connected to a drivetrain in the nacelle 3. The rotor includes a hub 4 and at least one wind turbine blade 5 connected to the hub 4. Three wind turbine blades 5 are shown here, but the hub 5 may be connected to two, four, or more wind turbine blades.

[0053] The wind turbine 1 is shown herein as an onshore wind turbine, but the wind turbine 1 may also be an offshore wind turbine 1.

[0054] Figure 2 A first exemplary embodiment of the drivetrain 6 of a wind turbine 1 is shown, wherein the rotor is mechanically connected to the input interface of a gearbox 7 to transmit torque to the gear stages of the gearbox 7. The hub 4 can be connected to the gearbox input via a low-speed interface.

[0055] The output interface of gearbox 7 is mechanically connected to the rotor of generator 8. Generator 8 also includes a generator stator arranged relative to the generator rotor. Each of the generator stator and generator rotor includes a plurality of pole units configured to interact with each other via at least one magnetic field. Rotation of the generator rotor relative to the generator stator generates an electrical output current in generator 8.

[0056] The output of generator 8 is connected to power conversion unit 9, which is configured to convert the electrical power output of generator 8 into a power output suitable for the power grid. In particular, the power output can be supplied to the power grid via a synchronous grid connection.

[0057] Figure 3 A second exemplary embodiment of the drivetrain 6 of the wind turbine 1 is shown, wherein the rotor is directly mechanically connected to the generator rotor to transmit torque to the generator 8. The hub 4 can be directly connected to the generator rotor via a low-speed interface.

[0058] The lubrication system 10 is also connected to at least the gearbox 7, and optionally to the generator 8, such as... Figure 2 As illustrated by the dashed lines in the diagram. The lubrication system 10 is configured to circulate a lubricating medium, such as oil, through one or more components of the transmission system 6.

[0059] Figure 4 An exemplary embodiment of a main bearing assembly 11 disposed between a rotor hub 4 and a gearbox 7 is shown. The main bearing assembly 11 includes a main shaft 12 configured to be connected at one end to the rotor hub 4 and at the other end to the gearbox input. The main shaft 12 is disposed within a main bearing housing 13.

[0060] A front main bearing 14 is arranged at the front end of the main shaft 12. Further, a rear main bearing 15 is arranged at the rear end of the main shaft 12. The main bearing housing 13 serves as a seat for the front main bearing 14 and the rear main bearing 15.

[0061] Figure 5 An exemplary embodiment of the lubrication system 10 according to the present invention is shown. Here, the lubrication system 10 is connected to the gearbox 7 via a piping system 18, but may also be connected to the main bearing assembly 11 and / or the generator 8.

[0062] The lubrication system 10 includes a pump 16 connected to a lubrication outlet of the gearbox 7. The pump 16 is arranged downstream of a main filter system 17 having one or more main filters configured to filter out debris from the lubricating medium. The main filter system 17 is also arranged upstream of a heat exchanger 19. The heat exchanger 19 is configured to cool or heat the lubricating medium to a desired temperature.

[0063] A distribution unit 21 is arranged upstream of the lubrication input section relative to the gearbox 7. The distribution unit 21 is configured to distribute the lubricating medium to the corresponding components in the gearbox 7.

[0064] A secondary filter system 20, having one or more secondary filters, is arranged downstream of the heat exchanger 19. The secondary filter system 20 is also arranged upstream of the distribution unit 21. The secondary filter system 20 is configured to further filter out debris from the lubricating medium.

[0065] Preferably, the ratio between the second filtration size of the secondary filter and the first filtration size of the primary filter is selected between 2 and 50.

Claims

1. A transmission system (6) for a wind turbine (1), wherein, The transmission system (6) includes: - A low-speed interface configured to connect to the rotor of the wind turbine (1) and provide mechanical torque directly or indirectly to the generator (8); - The generator (8) having a generator output section, wherein the generator (8) includes a generator rotor, the generator rotor being rotatably arranged relative to the generator stator and configured to interact with the generator stator via at least one magnetic field; and - A lubrication system (10) is arranged relative to at least the low-speed interface or the generator (8), the lubrication system (10) is configured to circulate a lubricating medium through at least the low-speed interface or the generator (8) via a piping system (18), and the lubrication system (10) includes at least one pump unit (16), at least one main filter system (17), at least one heat exchanger unit (19), and optionally at least one distribution unit (21). Its features are, The lubrication system (10) further includes at least one secondary filter system (20), wherein the secondary filter system (20) is arranged downstream of the heat exchanger unit (19).

2. The transmission system according to claim 1, characterized in that, The primary filter system (17) includes at least one primary filter having a first filtration rate, and the secondary filter system (20) includes at least one secondary filter having a second filtration rate, wherein the first filtration rate is equal to the second filtration rate.

3. The transmission system according to claim 1, characterized in that, The primary filter system (19) includes at least one primary filter having a first filtration rate, and the secondary filter system (20) includes at least one secondary filter having a second filtration rate, wherein the first filtration rate is different from the second filtration rate.

4. The transmission system according to claim 3, characterized in that, One of the main filter and the secondary filter is a finer filter, while the other of the main filter and the secondary filter is a coarse filter.

5. The transmission system according to any one of claims 1 to 4, characterized in that, The ratio of the second filter size of the secondary filter system (20) to the first filter size of the main filter system (17) is between 2 and 50.

6. The transmission system according to any one of claims 1 to 5, characterized in that, The first filter size is selected from the range of 2 μm to 500 μm.

7. The transmission system according to any one of claims 1 to 6, characterized in that, The second filter size is selected from the range of 10 μm to 2500 μm.

8. The transmission system according to any one of claims 1 to 7, characterized in that, It also includes a gearbox (7) having at least one gear stage, wherein the gearbox (7) includes a gearbox input configured to transmit torque to the at least one gear stage and a gearbox output configured to be connected to the generator rotor (8).

9. The transmission system according to any one of claims 1 to 8, characterized in that, The low-speed interface includes a main bearing assembly (11) having a main bearing housing (13), a main shaft (12), and at least one main bearing (14, 15) disposed between the main shaft (12) and the main bearing housing (13).

10. The transmission system according to any one of claims 1 to 8, characterized in that, The transmission system (6) is an integrated transmission system or a direct drive transmission system.

11. A wind turbine (1) comprising a wind turbine tower (2), a nacelle (3) disposed on top of the wind turbine tower (2), and a rotor comprising a hub (4) and at least one wind turbine blade (5), wherein, The rotor is arranged relative to the nacelle (3) and mechanically connected to the drive system (6) of the wind turbine (1), characterized in that the drive system (6) is constructed according to any one of claims 1 to 10.

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