Transmission arrangement for a wind turbine

Abstract

A transmission arrangement for a wind turbine comprising a gearbox which is coupled to an electrical generator. The electrical generator has a generator rotor that is rotatable with respect to a generator stator, wherein the generator rotor and the generator stator are contained within a generator housing. The electrical generator has a drive end and a non- drive end, and wherein the generator rotor is connected to a gearbox output member at the drive end, and is connected to a turner gear ring at the non-drive end. The generator housing comprises a plurality of auxiliary device interfaces each of which comprises a respective interface aperture that provides access to the turner gear. The electrical generator further comprises: at least one turner gear drive device that is configured to be mountable to one or more of the plurality of the auxiliary device interfaces, such that a drive pinion of the respective turner gear drive device engages with the turner gear; and 15 at least one power take-off device that is configured to be mountable to one or more of the plurality of auxiliary device interfaces, and wherein the at least one power take-off device has a respective driven pinion that engages with the turner gear.

Description

[0001] TRANSMISSION ARRANGEMENT FOR A WIND TURBINE

[0002] Technical Field

[0003] The present invention relates to an electrical generator in a wind turbine.

[0004] Background to the Invention

[0005] Wind turbines convert kinetic energy from the wind into electrical energy, using a large rotor with a number of rotor blades. A typical Horizontal Axis Wind Turbine (HAWT) comprises a tower, a nacelle on top of the tower, a rotor hub mounted to the nacelle and a plurality of wind turbine rotor blades coupled to the rotor hub. Depending on the direction of the wind, the nacelle and rotor blades are turned and directed into an optimal direction by a yaw system for rotating the nacelle and a pitch system for rotating the blades.

[0006] The nacelle houses many functional components of the wind turbine, including for example a main rotor shaft and one or more electrical generator, as well as convertor equipment for converting the mechanical energy at the rotor into electrical energy for provision to the grid. In some types of wind turbines, known as ‘direct drive’ systems, the main rotor shaft drives the electrical generator directly. However, it is more common for wind turbines to include a gearbox to step up the rotational speed between the main rotor shaft and the electrical generator, thus converting the low speed but high torque input from the main rotor shaft to a lower torque but higher speed input into the electrical generator. Together, the main rotor shaft, gearbox and generator constitute a power train of the wind turbine.

[0007] Many wind turbines have what is known as a ‘turner gear’ which provides for motor-drive positioning of the rotor during installation and maintenance of the blades. In some configurations, a turner gear may be provided at a region of the gearbox such that a turner drive of the turner gear is able to rotate the gearbox and, thus, to rotate the rotor at a slow speed to place the rotor into a desired angular position.

[0008] In another configuration, a turner gear is provided at a ‘non-drive end’ of the electrical generator.

[0009] Summary of the Invention According to an aspect of the invention, there is provided a transmission arrangement for a wind turbine comprising a gearbox which is coupled to an electrical generator. The electrical generator has a generator rotor that is rotatable with respect to a generator stator, wherein the generator rotor and the generator stator are contained within a generator housing. The electrical generator has a drive end and a non-drive end, and wherein the generator rotor is connected to a gearbox output member at the drive end, and is connected to a turner gear ring at the non-drive end. The generator housing comprises a plurality of auxiliary device interfaces each of which comprises a respective interface aperture that provides access to the turner gear. The electrical generator further comprises: at least one turner gear drive device that is configured to be mountable to one or more of the plurality of the auxiliary device interfaces, such that a drive pinion of the respective turner gear drive device engages with the turner gear; and at least one power take-off device that is configured to be mountable to one or more of the plurality of auxiliary device interfaces, and wherein the at least one power take-off device has a respective driven pinion that engages with the turner gear.

[0010] A benefit of the invention is that the power take-off devices can be mounted to the same auxiliary device interfaces to which the turner gear drive devices are mounted at other times during the use of the wind turbine. The auxiliary device interfaces therefore support a wide range of functionalities because they can be used to support turner drive gear devices during transport, installation and rotor maintenance, and can be used to support other systems during operational use of the wind turbine by virtue of the power take-off devices.

[0011] The power take-off devices may provide energy to different systems of the wind turbine. For example, the power take-off devices may include a hydraulic pump, an auxiliary electrical generator, an air moving device or compressor for an air conditioning system, for example. In general, the power take-off devices may provide means to generate energy in a suitable medium for storage for later use, and therefore may include an air compressor to store energy in a high-pressure accumulator, or an electrical generator to store electrical energy in a battery or capacitor system, merely by way of non-limiting example.

[0012] Preferably, at least one turner gear drive device remains mounted to the electrical generator at all times even when power take-off devices are provided at other positions at respective auxiliary device interfaces. In examples of the invention, the different ones of the auxiliary device interfaces may be identical such that the at least one turner gear drive device is configured to mountable to any one of the plurality of auxiliary device interfaces.

[0013] It is envisaged that the first turner gear drive device is one of a number of such devices, wherein two or more of the turner gear drive devices are removable from their respective auxiliary device interfaces and replaceable with respective ones of the plurality of power take-off devices.

[0014] In the situation where there are a number of power take-off devices are fixed to respective ones of the auxiliary device interfaces, they may perform different functions. For example, one of the power take-off devices may be a hydraulic pump for supplying hydraulic fluid to a fluid system within the wind turbine nacelle, and another one of the power take-off devices may be an auxiliary electrical generator configured to supply electrical power to an electrical consumer within the wind turbine nacelle.

[0015] The transmission arrangement may comprise a main shaft which is coupled to the gearbox. A gearbox output shaft may be axially aligned with the main shaft. The main shaft may be housed within a main bearing housing. The rotational axis of the main shaft may be aligned with a rotational axis of the electrical generator.

[0016] The main bearing housing may be connected to a gearbox housing of the gearbox. Similarly, the generator housing may be connected to the gearbox housing.

[0017] According to another aspect, there is provided a transmission arrangement for a wind turbine, comprising: a gearbox which is coupled to an electrical generator. The electrical generator may comprise a generator rotor that is rotatable with respect to a generator stator, wherein the generator rotor and the generator stator are contained within a generator housing; wherein the electrical generator has a drive end and a non-drive end, and wherein the generator rotor is connected to an output member of the gearbox at the drive end, and is connected to a turner gear at the non-drive end. The generator housing comprises a plurality of auxiliary device interfaces each of which comprises a respective interface aperture that provides access to the turner gear. The electrical generator further comprises at least one turner gear drive device that is configured to be mountable to one or more of the plurality of the auxiliary device interfaces, such that a drive pinion of the respective turner gear drive device engages with the turner gear; and at least one power take-off device that is configured to be mountable to one or more of the plurality of auxiliary device interfaces, and wherein the at least one power take-off device has a respective driven pinion that engages with the turner gear.

[0018] The at least one turner gear drive device may be configured to mountable to any one of the plurality of auxiliary device interfaces.

[0019] The at least one power take-off device may be configured to be mountable to any one of the plurality of auxiliary device interfaces.

[0020] There may be provided a plurality of power take-off devices, wherein at least two of the plurality of power take-off devices provide a different respective function. The power takeoff devices may be selected from: a gear-driven hydraulic pump; a gear driven electrical generator; a gear driven cooling system; a gear driven blower; a compressor.

[0021] In another aspect, there is provided a method for configuring an electrical generator of a wind turbine, wherein the electrical generator comprises: a generator rotor that is rotatable with respect to a generator stator, wherein the generator rotor and the generator stator are contained within a generator housing; wherein the electrical generator has a drive end and a non-drive end, and wherein the generator rotor is connected to an input drive shaft at the drive end of the electrical generator, and is connected to a turner gear at the non-drive end of the electrical generator. The generator housing comprises one or more auxiliary device interfaces providing a respective one or more interface apertures that provide access to the turner gear. The electrical generator further comprises: at least a first turner gear drive device that is configured to be fixable to one of the at least one auxiliary device interfaces, such that a drive pinion of the first turner gear drive device engages with the turner gear (70). The method comprises: removing the first turner gear drive device from a first auxiliary device interface of the at least one auxiliary device interfaces thereby exposing the respective interface aperture, fixing a power take-off device to the first auxiliary device interface, such that a driven pinion of the power take-off device engages with the turner gear.

[0022] Preferred and / or optional features of the invention are set out in the appended claims. It should be noted that preferred and / or optional features of the transmission of the first aspect of the invention, as they relate to the pivot pad thereof, may also be combined with the pivot pad of the second aspect of the invention, as defined above. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Examples of the invention will now be described, by way of example only, with reference to the attached drawings, in which:

[0024] Figure 1 is a perspective view of a horizontal-axis wind turbine within which the invention may be incorporated;

[0025] Figure 2 is a perspective view of a transmission arrangement for the wind turbine in Figure 1 , which includes a main shaft, a gearbox, and an electrical generator;

[0026] Figures 3 to 6 are schematic representations of aspects of a transmission arrangement exemplifying the invention.

[0027] DETAILED DESCRIPTION

[0028] A specific embodiment of the present invention will now be described in which numerous features will be discussed in detail in order to provide a thorough understanding of the inventive concept as defined in the claims. However, it will be apparent to the skilled person that the invention may be put into effect without the specific details and that in some instances, well known methods, techniques and structures have not been described in detail in order not to obscure the invention unnecessarily.

[0029] In order to place the embodiments of the invention in a suitable context, reference will firstly be made to Figure 1 , which illustrates a typical Horizontal Axis Wind Turbine (HAWT) 1 in which a transmission arrangement in accordance with examples of the invention may be implemented. Although the wind turbine is referred to as ‘horizontal axis’, it will be appreciated by the skilled person that for practical purposes, the axis is usually slightly inclined to prevent contact between the rotor blades and the wind turbine tower in the event of strong winds.

[0030] The wind turbine 1 comprises a tower 2, a nacelle 4 rotatably coupled to the top of the tower 2 by a yaw system (not shown), a rotor hub 6 mounted to the nacelle 4 and a set of wind turbine rotor blades 8 coupled to the rotor hub 6. The nacelle 4 and rotor blades 8 are turned and directed into the wind direction by the yaw system. The nacelle 4 houses many functional components of the wind turbine, including the main rotor shaft, generator, gearbox, and power converter for converting the mechanical energy of the wind into electrical energy for provision to the grid.

[0031] Figure 2 illustrates an example of a layout of part of a transmission system or arrangement 18 within the nacelle 4, including a main shaft 20, which extends through a main bearing housing 22, a gearbox 24 and a generator 26. The main shaft 20 is connected to, and driven by, the rotor hub 6 and provides input drive to the gearbox 24.

[0032] The gearbox 24 steps up the rotational speed of the low-speed main shaft 20 via internal gears (not shown) and drives a gearbox output shaft (also not shown in Figure 2). The gearbox output shaft in turn drives the electrical generator 26 (hereinafter simply ‘generator’), which converts the rotation of the gearbox output shaft into electricity. The electricity generated by the generator 26 may then be converted by other components (not shown) as required before being supplied to an appropriate consumer, for example an electrical grid distribution system. As shown in Figure 2, a pair of electrical conductors or ‘bus bars’ 27 are provided for power export purposes and would be connected to a suitable power converter system (not shown).

[0033] The gearbox 24 may be configured in various ways. For example, in some applications epicyclic or ‘planetary’ gearboxes may be used. As the skilled person would know, an epicyclic gearbox comprises a series of planet gears that are arranged about a central sun gear, and which collectively are arranged within an encircling ring gear. The ratio of the number of teeth between the ring gear, the planet gears and the sun gear determines the gear ratio of the gearbox. For clarity, detail of the gearbox will not be described in further detail here as the gearbox is not the principal subject of the invention. Suffice to say that another gearbox configuration could also be used, although it is currently envisaged that an epicyclic gearbox provides an elegant solution suitable for the confines of a wind turbine nacelle.

[0034] Turning to the generator 26, it should be noted that the generator 26 may be configured in various ways and the type and arrangement of components within the generator 26 will depend on the particular design of generator that is used. Nonetheless, the gearbox 24 and generator 26 in the illustrated example represent what is considered a medium-speed power transmission system in the wind power industry (e.g., the generator 26 having an intended operating speed in the range of 100-500 rpm, but examples are known which may operate up to 1800-2000rpm). As illustrated in Figure 2, it will be appreciated that the gearbox 24 and the generator 26 are in a ‘closely coupled’ configuration. Also, the gearbox 24 and the main bearing housing 22 are in a similarly closely coupled configuration. More specifically, it should be noted that a gearbox housing 30 of the gearbox 24 is joined directly to the main bearing housing 22 at an annular fixing 32 comprising an array of bolts. Furthermore, the gearbox housing 30 is joined directly to a generator housing 34 of the generator 26. The generator housing 34 is generally cuboidal in shape in the illustrated example, with a substantially square geometry in end view.

[0035] Also shown in Figure 2 is a support structure 36 for the main bearing housing 22. The support structure 36 is shown in dashed lines in Figure 2, and is shown here merely for context. The support structure 36 is in the form of a ‘base plate’ or ‘bed plate’ and acts as a pedestal on which rests the main bearing housing 22. Due to the close coupling of the main bearing housing 22 and the gearbox housing 30, the gearbox 24 can be considered to be suspended from the main bearing housing 22. Likewise, the generator 26 can be considered to be suspended from the gearbox 24 and, thus, the main bearing housing 22. Other forms of support can be provided to the gearbox 24 and the generator 26 but this is not essential in some applications.

[0036] Reference will now be made also to Figure 3, which provides a schematic view of some main components of the generator 26.

[0037] The generator 26 includes a rotor 40 and a stator 42 that are located within the generator housing 34. The rotor 40 is driven by a gearbox output member or shaft 44 to rotate within the generator housing 34. This arrangement in effect divides the generator housing 34 into a drive-end “DE” and non-drive-end “NDE”. On the drive-end, the generator housing 34 is coupled to the gearbox housing 30 using a suitable fastening system (e.g., bolts; not shown) or other suitable techniques, as is shown in Figure 2. On the non-drive end an opening 46 is provided through which internal components of the generator 26 can be accessed, for example for maintenance purposes.

[0038] The stator 42 is supported with the generator housing 34 between the drive end and nondrive ends by a suitable stator support 48. The stator support 48 may take various forms and will not be described in further detail here. The function of the stator support 48 is to hold the stator 42 in a stable position so it does not move angularly or axially in any direction during operation of the generator 26.

[0039] The stator 42 may take various configurations, and in one example may be a permanentmagnet generator with the stator 42 comprising a resin-impregnated assembly of steel laminations forming teeth on an iron core. The stator 42 may also include coils arranged in a distributed winding pattern between the teeth. When the rotor 40 rotates relative to the stator 42, permanent magnets on the rotor 40 induce a voltage in the windings. The windings are connected to a copper bus ring (not shown), which in turn is connected to the bus bars 27 (Fig. 2) for delivering the electrical output to a suitable power converter system (not shown) elsewhere in the wind turbine 1. Again, this is merely one possible configuration. Other configurations will be appreciated by persons skilled in wind turbine generator design, including those not involving permanent magnets.

[0040] The rotor 40 includes a rotor body 52 supporting permanent magnet assemblies 54 (or other flux-generating members, depending on the generator design). The permanent magnet assemblies 54 may comprise for example magnetic segments held within metallic annular rings which are secured to the rotor body 52. A rotor shaft 58 is coupled to the rotor body 52 by being secured thereto (e.g., by suitable fasteners such as bolts) or integrally formed therewith. The rotor body 52 may have a ‘hollow’ design such that the rotor shaft 58 does not pass through the annular interior between the magnetic assemblies 54. Such a rotor is disclosed in WO2020143888A1 and W02023 / 001348.

[0041] The rotor shaft 58 is coupled to a hub 60 of the rotor body 52. The connection between the rotor shaft 58 and the hub 60 may be achieved through a bolted connection (not shown) or any other suitable form. The rotor body 58 further includes a radial structure 62 that extends radially from the hub 60 towards the magnetic assemblies 54. Here, the radial structure 62 connects to a magnetic assembly support structure 64 which provides structural support for the magnetic assemblies 54. Such a configuration is described in more detail in W02023 / 001348 by way of example.

[0042] At least a portion of the rotor shaft 58 extends in an axial direction for connection to the gearbox 24, and specifically to the gearbox output member or shaft 44. It will be appreciated that the gearbox output shaft 44 is shown schematically in Figure 3 and that the connection between the gearbox output shaft 44 and the generator rotor shaft 58 is not shown. However, any suitable connection configuration is acceptable. Notably, the rotational axis of the generator 26, as shown as X in Figures 2 and 3 is coincident with the rotational axis of the gearbox 24 and also the main shaft 20 given the closely coupled design of the main shaft 20, gearbox 24 and generator 26 and also the design of the gearbox 24 which is an epicyclic gearbox in this example.

[0043] At the non-drive end of the generator 26 there is provided a turner gear 70. The turner gear 70 is of the form of a large circular gear wheel 72 with a set of external gear teeth 73, in this example. The gear teeth 73 are apparent in Figure 2 but are shown schematically in Figure 3.

[0044] As will be described, the function of the turner gear 70 is to enable the main shaft 20 to be rotated which is useful during blade installation and maintenance when the rotor 6 needs to be rotated to a predetermined angular position to permit blades to be installed, removed or worked on by maintenance personnel.

[0045] The turner gear 70 may be combined with a brake system (not shown) but that is not the focus of the examples of the invention so further discussion will not be provided.

[0046] The turner gear 70 is mounted to the rotor body 52 by any suitable mounting structure. In the illustrated example, the mounting is achieved by a mounting structure 74 which is fixed to the rotor body 52. The mounting structure 74 extends axially from the rotor body 52 and may take different forms, for example a number of axially-extending support members, or an integral annular extension of the rotor body 52.

[0047] The connection between the rotor body 52 and the turner gear 70 may be by way of bolted joints, welded joints, or the components may be formed by an integral cast structure, for example.

[0048] The non-drive end of the generator 26 also supports a number of turner gear drives 75. Four turner gear drives 75 are shown in Figure 2, and two of these are shown in the schematic view of Figure 3.

[0049] As shown, the turner gear drives 75 are supported by the generator housing 34 and, specifically, on an end face or ‘end shield’ 76 of the generator housing 34 so that they are positioned near to the turner gear 70. The upper one of the turner gear drives 75 is shown in more detail in the inset panel in Figure 3.

[0050] The turner gear drives 75 comprise respective pinions 78 that mesh with the gear teeth 73 of the turner gear 70. Thus, the turner gear drives 75 may be controlled to rotate the turner gear 70 when it is necessary to turn the driven components of the transmission system operatively coupled to the turner gear 70, namely, the generator rotor 40, the generator shaft 58, the output shaft of the gearbox 24 and the main shaft 20.

[0051] The use of the turner gear drives 75 during use and / or installation is outside the scope of this discussion. However, it should be noted that one or more turner gear drives 75 may be used, although a greater number of turner gear drives 75 provides a higher torque capability.

[0052] Typically, four to eight turner gear drives 75 may be provided, not all of which need to be used for a particular operation. It is envisaged that the location of the turner gear drives 75 may best be achieved by spacing them angularly about the turner gear 70 at equal angular intervals. This would ensure a balanced application of torque to the turner gear 70. However, this type of configuration is not essential.

[0053] During installation it may be necessary to use the full complement of turner gear drives 75 to take advantage of the full torque load. However, during a maintenance situation where the rotor hub 6 is balanced with a full set of blades, only one or two turner gear drives 75 may be needed. The turner gear drives 75 may comprise hydraulic motors in some examples or electric motors. It should be noted that the power supplies for the turner gear drives 75 have not been illustrated here nor described so as not to obscure the invention.

[0054] A pitch tube 80 is shown in Figure 2 and also in Figure 3 in dashed lines. The pitch tube 80 extends through the rotor body 52 and also the hollow central interior of the rotor shaft 58 along the axis X of the generator 26. As the skilled person would be aware, the pitch tube 80 accommodates hydraulic lines and / or electrical cables (not shown) that are routed through the rotating components of the transmission (e.g. the generator 26, the gearbox 24 and the main shaft 20) to the hub 6 for controlling a pitch system of the wind turbine 1 . If desired, one or more bearings (not shown) may be provided for supporting the pitch tube 80 for rotation with respect to the rotating components. As will be noted in the above discussion, the turner gear 70 is mounted to the non-drive end of the generator housing 34. This arrangement means that the generator 26 and the gearbox 24 can be coupled together closely in a compact manner since a turner gear does not need to be accommodated at the level of the gearbox.

[0055] In a medium- speed power transmission system like that described, such a consideration can be particularly important because a relatively large amount of torque may be required to rotate the turned gear 70. Also, the gearbox 24 and generator 26 can remain integrated (in the sense of their respective housings being closely coupled to one another, as discussed above) during servicing or removal of the turner gear 70 and / or turner gear drives 75 is desired.

[0056] Referring now to Figure 3 more closely, and with particular reference to the inset panel thereof, it will be noted that the turner gear drives 75 are removably attached to the generator housing 34 by way of a respective connection interface 82. The connection interface 82 comprises an interface aperture 84 and an interface fixing 86. The interface fixing 86 comprises a ring of bolt holes in this example that extend about the interface aperture 84. As will be discussed here, the connection interfaces 82 permit the connection of one or more auxiliary devices which are shown as turner gear drives 75 in Figures 2 and 3, but which may be other devices as discussed later. The connection interfaces 82 are for the purposes of connecting auxiliary devices thereto and so may also be referred to herein as auxiliary device interfaces. The interface fixing 86 may comprise any number of bolt holes, for example four or six or eight or more bolt holes. It is envisaged that the bolt holes may be distributed in the generator housing 34 at even angular intervals about the interface aperture 84 but this is not essential. The bolt holes may be provided in the sheet material of the generator housing, or they could be provided in a plate suitably attached e.g. by welding to the generator housing. The bolt holes could further be provided in bolt hole inserts that may be welded to the material of the generator housing.

[0057] The turner gear drive 75 is also shown in the inset panel as being ‘offered up’ to the connection interface 82. As can be seen the turner gear drive 75 comprises a drive body 90 operatively connected to the drive pinion 78. The drive body 90 is shown as being generally cylindrical in this example, as is a common shape for electrical motors. However, the precise shape of the drive body 90 is not important for its function. A mounting bracket 92 is also provided for the turner gear drive 75. Here the mounting bracket 92 is shown as being part of the drive body 90 and extending about the drive body 90 in the manner of a circular flange. The mounting bracket 92 may be an integral part of the drive body 90, for example being integrally formed with it. Alternatively, the mounting bracket 92 may be a separate component and connected to the drive body 90 by welding, for example.

[0058] The mounting bracket 92 is fixable to the connection interface 82. In this example, the fixing is achieved by a suitable set of fasteners such as bolts 94 that extend through apertures provided in the mounting bracket 90 and the interface fixings 86.

[0059] Any number of bolts may be provided, and the illustrated configuration is intended to be merely exemplary.

[0060] As can be seen in the inset panel of Figure 3, the turner gear drive 75 is ‘offered up’ to the connection interface 82 and moved in an axial direction so that the pinion 78 extends through the interface aperture 84 and into a position that it engages or ‘meshes’ with the gear teeth 73 of the turner gear 70.

[0061] The discussion will now turn to Figure 4 and 5 which demonstrate an aspect of the invention in which one or more of the turner gear drives 75 are removable from the generator housing 34 and which may be replaced by different auxiliary devices. The auxiliary devices have a different function to the turner gear drives 75. In general, the function of the auxiliary devices is to act as power take-off devices and so receive torque from the turner gear 70 as it rotates, in use, in contrast to the turner gear drives 75 delivering torque to the turner gear 70. As power take-off devices, they can be used to carry out useful work within the wind turbine. For example, the one or more power take-off devices may be configured as pumping systems to pump a fluid to a suitable system within the wind turbine. For example, the pumping system may be configured to supply a hydraulic fluid to a hydraulic fluid using system, or to pump a coolant to a coolant circuit. It is also envisaged that the power take-off devices may be used as a means of moving air around the nacelle, for example as part of an air conditioning system within the wind turbine nacelle or as a small-scale electric generator for powering selected internal systems of the wind turbine. Figure 4 shows one of the turner gear drives 75 (the lower device in the Figure) being removed from the connection interface 82. The removal of the turner gear drive leaves the interface aperture 84 exposed, and thereby able to accept another device.

[0062] Figure 5 shows the installation of another auxiliary device, in the form of a power take-off device 100 on the vacated lower one of the connection interfaces 82, as shown on Figure 4.

[0063] In Figure 5, the power take-off device 100 is shown schematically in the form of a hydraulic pump. The power take-off device 100 is connected to an inlet line 102 that couples the power take-off device 100 to a fluid tank 104, and an outlet line 106 that couples the power take-off device 100 to a hydraulic system 108 of the wind turbine. The hydraulic system may in principle be any hydraulic system of the wind turbine that is suitable to be powered by the capacity provided by the power take-off device 100. For example, the hydraulic system 108 may be a system of hydraulically powered tools, or a means to open hydraulically powered hatchways of the wind turbine nacelle.

[0064] The power take-off device 100 comprises a device body 110 which is connected to a driven pinion 112. This configuration will be noted as being similar to the configuration of the turner gear drive 75.

[0065] To enable the power take-off device 100 to be mounted to the connection interface 82, the device body 110 is provided with a respective mounting bracket 114. The mounting bracket 114 of the device body 112 is shown here as a circular flange in a similar manner to as discussed above.

[0066] It will be appreciated from the above discussion that the connection interfaces 82 that are distributed about the generator housing 34 and, more specifically, that are distributed about the opening 46 in the non-drive end of the generator housing 34, provide the flexibility to connect turner drive gear devices 75 or power take-off devices 100 at selected positions. This provides useful flexibility in configuring the generator housing 34 with a selected number of turner gear drive devices 75 and power take-off devices 100 during use. For example, in circumstances where a high torque requirement is needed, then all of the connection interfaces 82 may carry respective turner gear drive devices 75 in order to maximise the application of torque. However, where torque demands are lower, some of the connection interfaces 82 can be used to mount power take-off devices 100 to the generator housing instead 34 thereby to provide useful functionality for powering different fluid systems or electric consuming systems of the wind turbine.

[0067] Various modifications may be made to the illustrated examples without departing from the invention, as defined by the claims.

[0068] For example, it will be appreciated that in the illustrated examples, the turner gear comprises gear teeth 73 that are provided on a radially outward facing surface of the turner gear 70. This can be seen in the perspective view of Figure 2 and also in the schematic views of Figures 3 to 5.

[0069] However, in a variant on this design, the gear teeth of the turner gear may be provided on a radially inward facing surface of the turner gear 70. This configuration is exemplified in Figure 6. Figure 6 is similar to the schematic Figures discussed previously, so only the differences will be discussed here.

[0070] As can be seen, a plurality of turner gear drives 75 are mounted to the generator housing 34 such that drive pinions 78 thereof engage with gear teeth 73 of the turner gear 70.

[0071] The turner gear 70 is attached to the rotor body 52 by support structure 74, which may take various forms as discussed above. The turner gear 70 comprises a gear ring defining gear teeth 73 on a radial inward surface. The turner gear drives 75 are mounted to respective connection interfaces 82 in the same way as the previously illustrated examples. However, due to the comparatively enlarged dimension of the turner gear 70 the drive pinions 78 engage the gear teeth 73 of the turner gear 70 are radially inward positions.

[0072] In the example of Figure 6, it will be appreciated that the radially inward facing gear teeth 73 of the drive gear 70 does not affect the functionality of the turner gear 70 and the turner gear drives 75. Such a configuration of turner gear is disclosed in W02023001348 the contents of which are incorporated herein by reference.

Claims

CLAIMS1. A transmission arrangement for a wind turbine, comprising: a gearbox (24) which is coupled to an electrical generator (26), wherein the generator comprises a generator rotor (40) that is rotatable with respect to a generator stator (42), wherein the generator rotor and the generator stator are contained within a generator housing (34); wherein the electrical generator has a drive end (DE) and a non-drive end (NDE), and wherein the generator rotor is connected to a gearbox output member at the drive end, and is connected to a turner gear (70) at the non-drive end, wherein the generator housing comprises at least a first auxiliary device interface (82) comprising an interface aperture (84) that provides access to the turner gear (70), wherein the electrical generator further comprises: at least a first turner gear drive device (75) that is configured to be mountable to the first auxiliary device interface, such that the first turner gear drive device has a drive gear pinion (78) that engages with the turner gear; at least a first power take-off device (100) that is configured to be mountable to the first auxiliary device interface (82), and wherein the first power take-off device has a driven pinion (112) that engages with the turner gear (70) when the first power take-off device (100) is mounted to the auxiliary device interface (82).

2. The transmission arrangement of Claim 1 , wherein the power take-off device is a hydraulic pump.

3. The transmission arrangement of Claim 1 , wherein the power take-off device is an auxiliary electrical generator.

4. The transmission arrangement of any one of the preceding claims, wherein the first turner gear drive device (75) is one of a plurality of turner gear drive devices each of which is engageable with a respective one of a plurality of auxiliary device interfaces (82).

5. The transmission arrangement of Claim 4, further comprising a plurality of power take-off devices (100), wherein two or more of the plurality of turner gear drive devices (75) are removable from their respective auxiliary device interfaces (82) and replaceable with respective ones of the plurality of power take-off devices.

6. The transmission arrangement of Claim 5, wherein when multiple ones of the plurality of power take-off devices (100) are fixed to the generator housing (34) at the respective auxiliary interfaces (82), at least two of the power take-off devices provide a different respective function.

7. The transmission arrangement of Claims 4 to 6, wherein the generator housing (34) has at least one of the plurality of turner gear drive devices (75) fixed thereto and at least one of the plurality of power take-off devices (100) fixed thereto.

8. The transmission arrangement of any one of the preceding claims, wherein the gearbox includes an output member that has a rotational axis that is aligned with the generator rotor (40).

9. The transmission arrangement of any one of the preceding claims, including a main shaft (20) which is supported in a main bearing housing (22).

10. The transmission arrangement of Claim 9 wherein the main bearing housing (22) is connected to a gearbox housing (30) of the gearbox (24).11 . The transmission arrangement of Claim 10, wherein the generator housing (34) is connected to the gearbox housing (30).

12. The transmission arrangement of any one of Claims 1 to 9, wherein the generator housing (34) is connecting to a gearbox housing (30) of the gearbox (24).

13. A method for configuring a transmission arrangement of a wind turbine comprising a gearbox (24) which is coupled to an electrical generator (26), wherein the electrical generator comprises: a generator rotor (40) that is rotatable with respect to a generator stator (42), wherein the generator rotor and the generator stator are contained within a generator housing (34); wherein the electrical generator has a drive end (DE) and a non-drive end (NDE), and wherein the generator rotor is connected to an output member of the gearbox at the drive end of the electrical generator, and is connected to a turner gear (70) at the non-drive end of the electrical generator, wherein the generator housing (34) comprises one or more auxiliary device interfaces (82) providing a respective one or more interface apertures (84) that provide access to the turner gear (70), wherein the electrical generator further comprises: at least a first turner gear drive device (75) that is configured to be fixable to one of the at least one auxiliary device interfaces (82), such that a drive pinion (78) of the first turner gear drive device (75) engages with the turner gear (70); and wherein the method comprises: removing the first turner gear drive device (75) from a first auxiliary device interface (82) of the at least one auxiliary device interfaces thereby exposing the respective interface aperture (84), fixing a power take-off device (100) to the first auxiliary device interface (82), such that a driven pinion (112) of the power take-off device (100) engages with the turner gear (70).

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