Gear arrangement for wind turbine

Abstract

Abstract and drawing info chevron_right A gear module (1) is described comprising: - two parallel planetary gears (22) arranged one after the other along a rotation axis (A) of the gear module (1), each planetary gear comprising a sun gear (24), a ring gear (28) and a set of planetary gears (26), the two sets of planetary gears (26) being arranged in a common planetary gear carrier (30), and the two sun gears (24) being connected together to a common rotation shaft (32) along the rotation axis (A) of the gear module (1); - a gear module housing (42) encircling at least a portion of the two planetary gears (22), the gear module (1) further comprising an internal torque distributor (43) connected to each of the ring gears (28) and to the gear module housing (42), such that the two ring gears (28) are allowed to rotate relative to each other about the rotation axis (A) during use. A gear assembly (10) comprising two such gear modules (1) as well as a wind turbine comprising a gear module (1) or a gear assembly (10) is also described.

Description

[0002] GEAR MODULE FOR WIND TURBINE

[0003]

[0004] The invention relates to a gear module for a wind turbine. More specifically, the invention relates to a gear module comprising two planetary gears operating in parallel to distribute load between the two planetary gears. The invention also relates to a gear assembly comprising two single gear modules and a wind turbine comprising a gear module or a gear assembly.

[0005] The development of wind turbines has been moving towards increasingly larger structures with correspondingly increased power. Today, wind turbines are being developed with power up to and even over 20 MW. Wind turbines are driven by a wind propeller that is set into rotation by a wind flow. To achieve the desired, large effects, the diameter of the propeller must be increased. With a turbine size of over 20 MW, the rotation speed becomes very low. For example, a wind propeller belonging to a 20 MW installation will typically have a rotation speed of around 7.5 rpm (revolutions per minute). Low rotation speed combined with high power gives extremely high torques, often in the order of 20,000,000 Nm. Additional loads arise due to a "disorderly" load field, both as a result of deviations from production tolerances and extreme loads.

[0006]

[0007] The gear system in such a wind turbine must be able to transfer the rotational torque from the propeller and convert this into high input speed on a generator, which produces electricity, in an efficient manner. The gear system is currently one of the biggest challenges that must be solved for the large wind turbines of the future.

[0008]

[0009] One of the challenges is to provide a gear system that is strong with a long service life and at the same time has low weight. In today's wind turbines, planetary gear solutions are mainly used, i.e. gears with a central sun gear with surrounding planetary gears that engage the sun gear and a surrounding ring gear. When such gear systems are to be able to handle large torques, as exemplified above, they become very large, which presents significant challenges. The ring gear with teeth often has a diameter of around 6-8 m for the largest turbines, which makes production, installation and maintenance difficult. The large torques and the large ratio also wear out the components in the gear system,

[0010]

[0011] P30966NO00 description and requirements, priority

[0012] This results in high wear and tear and frequent need for replacement parts, which are as large and difficult to handle as the original components. The development towards ever larger wind turbines with associated large gears also results in a need for certification of ever new and larger gears.

[0013]

[0014] The invention aims to remedy or reduce at least one of the disadvantages of the prior art, or at least to provide a useful alternative to the prior art.

[0015]

[0016] The object is achieved by the features set forth in the description below and in the subsequent patent claims.

[0017]

[0018] One possibility for reducing the size of individual components is to use modular solutions that can be scaled as needed. In this way, production and installation can be made more efficient and maintenance and the use of spare parts can be minimized, as will be apparent from the description below. In the present description, a gear solution is presented where the gear can be built up from one or more standardized gear modules adapted to different sizes of the wind turbine.

[0019]

[0020] According to a first aspect, the invention relates to a gear module comprising:

[0021] - two parallel planetary gears arranged one after the other along a rotational axis of the gear module, each planetary gear comprising a sun gear, a ring gear and a set of planetary gears, the two sets of planetary gears being arranged in a common planetary gear carrier, and the two sun gears being connected to a common rotational shaft along the rotational axis of the gear module;

[0022] - a gear module housing encircling at least a portion of the two planetary gears, the gear module further comprising an internal torque distributor connected to each of the ring gears and to the gear module housing, such that the two ring gears are allowed to rotate relative to each other about the axis of rotation in use.

[0023]

[0024] By allowing the two ring gears to rotate relative to each other about the axis of rotation during use, uneven loading on the two planetary gears is avoided or substantially reduced. Such uneven loading, which could lead to overloading of individual components, can be a result of misalignments due to torque loading and manufacturing tolerances. By assembling two planetary gears in this way and allowing them to operate in parallel with torque distribution, one large planetary gear, as exemplified above with a diameter of 6-8 meters, can be replaced by two smaller planetary gears assembled in a gear module according to the first aspect of the invention.

[0025]

[0026] P30966NO00 description and requirements priority

[0027] In one embodiment, the internal torque distributor may comprise a plurality of shafts, each end of each of the shafts being supported in one of the annular rings and the shaft being supported, between its two ends, in the gear module housing. The annular rings may in one embodiment be formed with holes distributed at equal distances around the entire circumference, the ends of the shafts being supported in these holes. Similarly, the gear module housing may be formed with an internal flange having a corresponding number of holes with a corresponding distribution.

[0028] In an advantageous embodiment, the support may be via spherical bearings, such as roller bearings, whereby the two annular rings may be allowed to twist relative to each other with full freedom of rotation.

[0029]

[0030] In an alternative embodiment, the internal torque distributor may be designed as a differential. The two ring rings may be connected by a plurality of bevel gears mounted around rotation bolts that are radially on the axis of rotation of the planetary gear and in engagement with an external toothing groove / gear on each of the ring rings. The bevel gears are positioned axially between the ring rings so that each bevel gear is in engagement with the toothing groove of each of the ring rings axially therebetween. The bevel gears may further preferably be distributed evenly around the inner circumference of the gear module housing. In one embodiment, there may be eight bevel gears distributed inside the gear module housing. The two ring rings are thus allowed some rotation relative to each other about the axis of rotation of the gear module. In "perfect" operation, without biases from production tolerances and torque, the two ring rings will be stationary and the bevel gears will not rotate about their own axis.In the event of misalignment, as a result of manufacturing tolerances and torque loading, some relative twisting is allowed between the two ring rings to equalize the load on the gear module components.

[0031]

[0032] According to a second aspect, the invention relates to a gear assembly comprising two parallel gear modules according to the first aspect of the invention, wherein the rotary shafts connected to the sun gears in each of the gear modules are output rotary shafts, wherein the planet gear carriers of the two gear modules are together arranged to be connected to an input rotary torque, and wherein the output rotary shafts from each gear module are connected together in an external torque distributor, such that the two output rotary shafts are allowed to rotate relative to each other about the axis of rotation in use.

[0033]

[0034] By connecting the output rotation shafts to an external torque distributor, it is also possible to distribute the output rotation torque from the two output rotation shafts. The external torque distributor rotates together with the output rotation shafts, so that it can be connected to a generator in use. In this way, the

[0035]

[0036] P30966NO00 description and requirements priority

[0037] biases from torque loading and manufacturing tolerances on the output rotary shafts, so that the output rotary torque from the two gear modules is equalized. This allows some relative twisting of the two output rotary shafts without overloading individual components, thereby enabling the assembly of multiple gear modules.

[0038]

[0039] A significant advantage of connecting gear modules in this way is that instead of building increasingly larger gears adapted to increasingly larger wind turbines, several gear modules with standard design and size can be assembled as needed, i.e. according to the size of the wind turbines. This simplifies production, installation and maintenance to a significant extent. By using standard modules, which are assembled as needed, one also avoids having to certify new, specially designed gear solutions for new wind turbines of ever-increasing size. In this description and in the figures, which are described in detail below, the gear assemblies are exemplified with a combination of two gear modules operating in parallel, but it should also be understood that a larger, even number of gear modules could be used if needed.

[0040]

[0041] The two planetary carriers should both be connected to the input torque in parallel. A practical way to do this is to connect the input torque to the planetary carrier closest to the input torque, such as a rotor on a wind turbine, and then connect the two planetary carriers together with an adapter, a rigid connection that causes the two planetary carriers to rotate together at the same rotational speed as the input torque.

[0042]

[0043] In one embodiment, the external torque distributor may comprise an external torque distributor housing and two rotating discs, each rotating disc being connected to a distal end of a respective output rotary shaft from each of the gear modules, the external torque distributor further comprising shafts supported with one end in each of the rotating discs and in the external torque distributor housing between their respective ends. In this way, the two output rotary shafts are permitted to rotate relative to each other about the axis of rotation. In the same way as for the internal torque distributor, described above, this enables a three-point support of the two output rotary shafts relative to each other. One difference is that the external torque distributor rotates together with the output rotary shafts, while the internal torque distributor, during normal operation and with the exception of the rotations that occur due to misalignments and particularly high loads, is at rest.The two rotating discs, which are rigidly connected to respective output rotating shafts, comprise in one embodiment a plurality of holes evenly distributed around the circumference, and where the shafts are supported in these holes. The external torque distributor housing may correspondingly be out-.

[0044]

[0045] P30966NO00 description and requirements priority

[0046] formed with a flange that projects radially inwardly into the torque distributor housing, and where the flange is formed with an equal number of holes with a corresponding distribution around the circumference. In an advantageous embodiment, the shafts can be supported to the rotation discs and to the external torque distributor housing via spherical bearings, such as roller bearings. The two output rotation shafts are thus allowed to twist relative to each other with full rotational freedom while at the same time compensating for unevenness so that the output torque from the two gear modules is distributed evenly in the external torque distributor, which in turn will typically be connected to a generator.

[0047] In one embodiment, the output rotary shaft from one gear module may extend internally and concentrically with the output rotary shaft from the other gear module along the axis of rotation towards the external torque distributor. The output rotary shaft from the gear module closest to the input rotary torque thus has a smaller diameter than the output rotary shaft from the other gear module and extends internally into this other output rotary shaft. In this way, the two gear modules may be conveniently placed one after the other along the common axis of rotation while allowing easy access to the distal ends of the rotary shafts in the external torque distributor housing.

[0048]

[0049] In a third aspect, the invention relates to a wind turbine comprising a gear module according to the first aspect of the invention, wherein the wind turbine comprises a rotor coupled to the planetary gear carrier of the gear module with an input rotational torque, and wherein the wind turbine further comprises a generator coupled to the common rotational shaft.

[0050]

[0051] In a fourth aspect, the invention relates to a wind turbine comprising a gear assembly according to the second aspect of the invention, wherein the wind turbine comprises a rotor coupled to the planetary gear carriers of the gear assembly with an input rotational torque, and wherein the wind turbine further comprises a generator coupled to the external torque distributor.

[0052] The wind turbine according to the third aspect of the invention thus uses a single gear module according to the first aspect of the invention, while the wind turbine according to the fourth aspect of the invention uses a gear assembly according to the second aspect of the invention. The modularity of the gear modules allows an even number of such gear modules to be assembled as needed.

[0053] In one embodiment, the wind turbine may include a torque absorber that connects the gear module housing(s) to a wind turbine foundation, such as a platform on top of a wind turbine column / tower where the nacelle is located. Extreme torque loads / torque peaks may cause the planetary gears to lock up completely or partially. The torque will thus be transferred from the ring gears to the gear module housing(s) due to their common bearing arrangement.

[0054]

[0055] P30966NO00 description and requirements priority

[0056] ring in the internal torque distributor. By connecting the gear module housing(s) to one or more torque absorbers / shock absorbers, incoming rotational torque will be able to rotate the entire gear module housing around the gear module's rotational axis so that the torque is absorbed in the torque absorber(s). The torque absorber may in one embodiment be a hydraulic cylinder. Alternatively, the torque absorber may be a pneumatic cylinder or a mechanical spring.

[0057]

[0058] In the following, examples of preferred embodiments are described, which are illustrated in the accompanying drawings, where:

[0059]

[0060] Fig. 1 shows a wind turbine according to the present invention;

[0061]

[0062] Fig. 2 shows, on a larger scale, details of the wind turbine nacelle;

[0063]

[0064] Fig. 3 shows, in perspective, a gear module according to the present invention;

[0065]

[0066] Fig. 4 shows an exploded view of the gear module from Fig. 3;

[0067]

[0068] Fig. 5 shows, enlarged, a detail from Fig. 4

[0069]

[0070] Fig. 6 shows, in perspective, a gear assembly according to the present invention;

[0071]

[0072] Fig. 7 shows an exploded view of the gear assembly of Fig. 6;

[0073]

[0074] Fig. 8 shows, enlarged, a detail from Fig. 7;

[0075]

[0076] Fig. 9 shows the gear assembly of Fig. 6 viewed from above;

[0077]

[0078] Fig. 10 shows a section seen through the line AA of Fig. 9;

[0079]

[0080] Fig. 11 shows a section taken along the line DD of Fig. 10;

[0081]

[0082] Fig. 12 shows a section taken along line BB of Fig. 10;

[0083]

[0084] Fig. 13 shows a section seen through the line EE from Fig. 9

[0085]

[0086] Fig. 14 AB shows, enlarged, respectively, details F and G from Fig. 10;

[0087]

[0088] Fig. 15 AE shows a first, alternative embodiment of an external torque distributor;

[0089]

[0090] P30966NO00 description and requirements priority

[0091] Fig. 16 AE shows a second, alternative design of an external torque distributor;

[0092]

[0093] Fig. 17 AB shows the external torque distributor from Fig. 16 exploded and in section, respectively;

[0094] and

[0095]

[0096] Fig. 18 shows an alternative embodiment of an internal torque distributor.

[0097]

[0098] .

[0099]

[0100] In the following, reference numeral 1 will refer to a gear module according to the first aspect of the invention. Reference numerals 10 and 100 refer respectively to a gear assembly according to the second aspect of the invention and to a wind turbine according to the fourth aspect of the invention. All positional references refer to the position shown in the figures. The same or corresponding elements are indicated by the same reference numeral. For the sake of clarity, some elements may be without reference numerals in some figures.

[0101]

[0102] A person skilled in the art will understand that the figures are only schematic diagrams. The relative relationships between individual elements may also be indicated.

[0103]

[0104] It should also be noted that components in a section are shaded with the same shading in the figures. Different shading is therefore not used to distinguish different components. Components that lie behind the section itself, but which would be visible if one looks into the section, are shown unshaded in the figures.

[0105]

[0106] Fig. 1 and 2 show a wind turbine 100 according to the fourth aspect of the invention. The wind turbine 100 comprises a column / tower 2 composed of sections 4 and flange connections 5. On top of the tower 2 is arranged a platform 6 on which a nacelle 8 is mounted, as best shown in Fig. 2. The nacelle 8 includes a gear assembly 10 associated with a generator 12, which is driven by a wind turbine rotor (propeller) 14. The rotor 14 includes a plurality of turbine blades 16 associated with a hub 18, which rotate about an axis of rotation A, corresponding to the axial direction / longitudinal axis of the nacelle 8 and the axis of rotation of the gear modules 1 and the gear assembly 10. A torque T generated by the wind rotating the turbine blades 16 is transmitted to the generator 12 via the gear assembly 10, as will be explained in detail below. The gear assembly 10 comprises two gear modules 1 operating in parallel, so that the load on the gear assembly 10 from the input torque T from the rotor 14 is distributed over several components.As explained above, the propeller 14, depending on the turbine size, has a rela-

[0107]

[0108] P30966NO00 description and requirements priority

[0109] tively low rotational speed, and there is a need for transmission via the gear assembly 10, which is subjected to very high torque loads.

[0110]

[0111] In Fig. 3 a single gear module 1 according to the first aspect of the invention is shown in perspective, while Fig. 4 shows an exploded view of the same gear module 1. An input adapter 20, here in the form of a spline connection, connects the input rotational torque T from the rotor 14 to the gear module 1. The gear module 1 includes two planetary gears 22, each comprising a sun gear 24, a plurality of planet gears 26 and a ring gear / gear 28. The planet gears 26 for each of the planet gears 22 are mounted in a common planet gear carrier 30. The spline connection 20 is connected to the planet gear carrier 30 so that it rotates at the same rotational speed as the rotor 14 of the wind turbine 1. In the embodiment shown, each planet gear 22 comprises eight planet gears 26, i.e. the gear module 1 comprises sixteen planet gears 26. The two sun gears 24, which rotate at the same speed, are connected to a common output rotary shaft 32.The output rotation shaft 32 is provided with an output spline adapter / coupling 34 for connection to the generator 12. If several such gear modules 1 are to be assembled with an external torque distributor, the output spline adapter 34 will instead be connected to the external torque distributor, as will be explained below with reference to Figures 6-17. The planet gears 26 are set in rotation about a separate rotation axis P through the rotation of the planet gear carrier 30 about the longitudinal axis A and through their engagement with internal toothing in the ring rings 28. The sun gears 24 are rotated about the rotation axis A through their engagement with the toothing on the planet gears 26 so that the sun gears 24 rotate faster, but in the opposite direction of the input torque T as will be known to a person skilled in the art. The two ring rings 28 are further designed with a plurality of holes 36 in the longitudinal direction of the gear module 1 around its circumference.In each hole 36, one end of a shaft 38 is supported, so that opposite ends of each shaft 38 are supported in each ring 28. In the embodiment shown, the shafts 38 are supported in the holes 36 around the ring 28 via spherical bearings in the form of journal bearings 40. The spherical bearings 40 make it possible for the ring 28 to be allowed to twist somewhat relative to each other with full freedom of rotation. This further means that the input torque T can be distributed substantially equally between the two planetary gears 22 in the gear module 1 despite biases resulting from production tolerances and high loads. This essentially avoids overloading individual components, in particular individual planetary gears 26.

[0112]

[0113] The gear module 1 further comprises a gear module housing 42 which surrounds the ring rings 28 and the planet gear carrier 30 so that only the two groove couplings 20, 34 project outside the gear module housing 42 in their respective directions parallel to the axis of rotation A. Each of the shafts 38 is, between its two ends, also supported in an internal flange 44 in the gear module housing 42 via spherical bearings 40.

[0114]

[0115] P30966NO00 description and requirements priority

[0116] so that each shaft 36 has a three-point bearing. An enlarged single shaft 38 with journal bearings 40 is shown in Fig. 5. In the embodiment shown, the shaft 38 is widest towards the middle, where it will be supported in the gear module housing 42, while it is symmetrically tapered towards its ends, which will be supported in each ring 28. In the embodiment shown, the shafts 38, together with the rings 28, the flange 44 and the journal bearings 40, constitute an internal torque distributor 43 in the gear module 1. An alternative embodiment of an internal torque distributor 43 is shown in Fig. 18 and discussed below.

[0117]

[0118] The portion of the flange 44 that projects radially inwardly into the gear module housing 42 is formed with a plurality of through holes 45, best shown in Fig. 14A. The number of holes 45 in the inner flange 44 corresponds to the number of holes 36 in each of the annular rings 28 so that the shafts 38 are provided with a three-point bearing, as explained above. A portion of the flange 44 also extends radially outwardly beyond the outer periphery of the gear module housing 42 and forms two portions with an enlarged radius and holes 46, for connection to a torque absorber as explained below.

[0119]

[0120] Fig. 6 shows two gear modules 1 according to the first aspect of the invention assembled into a gear assembly 10 according to the second aspect of the invention. Fig. 7 shows an exploded view of a similar solution, however with input and output spline couplings, which are not shown in Fig. 6, but without torque absorbers. As can be seen in Fig. 6, torque absorbers 50 are connected into the holes 46 in the flange 44 via bolted connections. As best shown in Fig. 9 and 11, two torque absorbers 50 are connected to each gear module 1. In the event of large and sudden torque loads (peak loads), the input torque T will not be fully or partially transmitted through the gear assembly 10 to the generator 12, as the planetary gears 22 will be fully or partially locked. Excess torque will have to be extracted from the pinion carriers 30, which are coupled to the incoming rotational torque T, and further through the gear module housing 42 which is rotatably supported to a surrounding structure via the torque absorbers 50.If the internal torque distributor 43 reaches maximum torsional deflection, additional excess torque will also be taken out into the torque absorber 40 via the gear module housing 42. The surrounding structure will typically be the platform 6 on top of the wind turbine tower 2 where the nacelle 8 is located. The torque absorbers 50 are in the shown embodiment produced as hydraulic cylinders that function as shock absorbers on top of the wind turbine 100. In alternative embodiments, pneumatic cylinders or mechanical spring solutions can be used designed to be able to receive and dampen sudden torque loads from the gear assembly 10.

[0121]

[0122] The two gear modules 1 are connected by the planet carrier 30 in each of the gear modules 1 being connected together via an adapter 48. This means in practice that the input torque T rotates

[0123]

[0124] P30966NO00 description and requirements priority

[0125] both planetary gear carriers 30 simultaneously. The ratio is the same as if only one gear module 1 had been used, or only one, single planetary gear 22 for that matter, but the load is distributed over several components. Output shafts from each of the gear modules 1 are connected together in an external torque distributor 52 as will be explained below. When two gear modules 1 are assembled into a gear assembly 10, the output rotation shaft 32 is extended from one gear module 1, that is, from the gear module 1 that is furthest from the generator 12, so that the first output rotation shaft 32 extends centrally, inside an output rotation shaft 54 ​​from the second gear module 1 along the rotation axis A. The first rotation shaft 32 is thus designed with a smaller diameter than the second rotation shaft 54, which is hollow inside, as can best be seen in the cross-section of Fig. 10.The first output rotary shaft 32 is formed with spline couplings 55 and the second output rotary shaft 52 is provided with spline couplings 56, as best shown in Fig. 7. Via the spline couplings 55, 56 on the output rotary shafts 32, 52, the rotary shafts are connected to respective rotary discs / plates 58, 60, which are part of the external torque distributor 52. Each of the rotary discs 58, 60 is formed with a plurality of holes 62 distributed around the circumference of the rotary discs 58, 60. A shaft 64 is supported at its ends in these holes 62 via spherical bearings 40, here in the form of journal bearings, so that the first end of the shaft 64 is supported in the output rotation disk 58 connected to the first output rotation shaft 32 and the second end of the shaft 64 is supported in the rotation disk 60 connected to the second output rotation shaft 54. The external torque distributor 52 also includes a torque distributor housing 66 which surrounds the rotation disks 58, 60.The torque distributor housing 66 is provided with an internal flange 68, the flange being formed with a plurality of through holes 70 distributed around the circumference. There are as many holes 70 in the internal flange 68 as in each of the rotation discs 58, 60 so that the shafts 64 in the external torque distributor also have a three-point bearing via spherical (here spherical) bearings 40, which enable relative movement / rotation of the two output rotation shafts 32, 54. A spline adapter / coupling 34, which corresponds to the spline coupling 34 shown in Figs. 3 and 4 for a single gear module 1, is attached to the external torque distributor 52, which rotates with the output shafts 32, 54, and is further connected to the generator 12 (connection not shown in detail). The shaft 64 with three journal bearings 40 is shown enlarged in Fig. 8.

[0126]

[0127] Fig. 9 shows the gear assembly 10 seen from above with input spline coupling 20 at one end and output spline coupling 34 at the other end. Two torque absorbers 50 are connected to each of the gear modules 1 at one end and to the platform / plateau 6 of the wind turbine (not shown) at the other.

[0128]

[0129] P30966NO00 description and requirements priority

[0130] Fig. 10 shows a section seen through the line AA from Fig. 9. The spline adapter 20 is connected to the planet gear carrier 30 in the first gear module 1 as explained above. The planet gear carrier 30 thus rotates at the same rotational speed as the rotor 14 of the wind turbines 100, which is not shown in this figure. Two sets of eight planet gears 26 rotate with the planet gear carrier 30 about the gear module 1 rotation axis A, at the same time as each planet gear 26 rotates about its own rotation axis P about the rotation shaft 27. The planet gears 26 rotate on their outer side in engagement with the ring gear 28, which in normal operation is the part of the planetary gear 22 that is at rest (with the exception of minor twisting and as a result of unevenness and particularly large torque loads, as mentioned above). On their inside, the planet gears 26 rotate in engagement with a sun gear 24, each set of eight planet gears 26 with one sun gear 24. The two sun gears 24, which are part of a gear module 1, are together connected to the gear module 1's output rotation shaft 32.The planetary gear carrier 30 in one gear module 1 is connected to the planetary gear carrier 30 in the other gear module 1 via the adapter 48. The two gear modules 1 are essentially the same, with the exception of the output shafts 32, 54, where the output rotation shaft 32 from the first gear module 1 (connected to the input spline coupling 20) runs concentrically inside along the axis of rotation A in the output rotation shaft 54 ​​from the second gear module 1. The annular rings 28 are, as explained above, designed with holes 36 (see Fig. 14A) throughout parallel to the axis of rotation A for supporting shafts 38 in journal bearings 40. This can best be seen in Fig. 14A which shows detail F in an enlarged version from Fig. 10. The gear module housing 42 surrounds the ring collars 28 externally, while the flange 44 projects radially inwardly with the holes 45 which are aligned with the holes 36 in the ring collars 28 so that the shafts 38 are spherically supported at three points.In the event of large torque loads and complete or partial locking of the planetary gear 22, the incoming rotational torque T will be transferred to the planetary wheel carriers 30, outwards to the ring gears 28 and the shafts 38, via the journal bearings 40 to the gear module housing 42 and out into the torque absorbers 50. Such a peak load, when the planetary gear 22 engages, will thus rotate the entire gear assembly 10 about the axis of rotation A with torque absorption in the torque absorbers 50.

[0131]

[0132] Fig. 11 is a section through the lines DD from Fig. 10. Here, the outermost gear module housing 42 is seen with the shafts 38 supported in the holes 45 (see Fig. 14A) in the flange 44. Neither the planet gear 26 nor the sun gear 24 are located in the section and are therefore not shaded.

[0133]

[0134] Fig. 12 shows a section through the line BB from Fig. 10. Here the section passes through the planet gears 26 and the sun gears 24 and the engagement with the internal teeth of the ring gear 28 and between the planet gears 26 and the sun gears is clearly shown. The section through the shafts 38 is made through the ring gear 28 and it can be clearly seen that the diameter of the shafts in this section is smaller than in Fig. 11.

[0135]

[0136] P30966NO00 description and requirements priority

[0137] The focus will now be directed back to Fig.10. The output rotation shaft 32 from the first gear module 1 extends inside the output rotation shaft 54 ​​from the second gear module 1 along the rotation axis A in the direction of the external torque distributor 52. At their distal ends, each of the output rotation shafts 32, 54 is formed with spline couplings 55, 56. As can be seen in the figure, the output rotation shaft 32 from the first gear module 1 extends past the distal end point of the output rotation shaft 54 ​​from the second gear module 1. Via the spline couplings 55, 56 (see Fig. 7), the distal ends of the output rotation shafts 32, 54 are connected to respective rotation discs 58, 60. As explained above, the rotation discs 58, 60 are included in the external torque distributor 52.Between the rotating discs 58, 60 is the internal flange 68 of the torque distributor housing 66, where through holes 70 in the internal flange 68 are aligned with the holes 62 in each of the rotating discs 58, 60 so that the shafts 64 of the external torque distributor are supported at three points via journal bearings 40 as can best be seen in Fig. 14B which shows detail G of Fig. 10 on a larger scale. Output spline adapter 34 is connected to the external torque distributor housing 66 for connection to the generator 12, which is not shown in this figure.

[0138]

[0139] Fig. 13 shows a section through the line EE from Fig. 9 through the external torque distributor housing 66. The section is taken between the two rotation discs 58, 60 in the middle of the shafts 64 in the internal flange 68 in the torque distributor housing 66, with holes 70 for mounting the shafts 64.

[0140]

[0141] The external torque distributor 52 shown in Figures 9, 10, 13 and 14B is only one of a number of different ways of distributing torque between the output shafts 32, 54. Figures 15-17, which will be described briefly below, show alternative ways of distributing such output torque.

[0142]

[0143] Fig. 15A-15E show the use of a differential solution in an external torque distributor housing 66'. Fig. 15A shows the torque distributor housing 66' viewed from one end along the axis of rotation A, while Fig. 15E shows a section through the line AA of Fig. 15A. Fig. 15C shows the external torque distributor 52 viewed in perspective, while Figs. 15B and D show the external torque distributor 52 viewed from the side. As best seen in the section in Fig. 15E, the torque distributor housing 66' is provided with a first differential disk 72 and a second differential disk 74 formed with teeth adapted to rotate in engagement with the spline couplings 55, 56 on the first output rotary shaft 32 and the second output rotary shaft 54, respectively, the rotary shafts 32, 54 not being shown in the figure. Inside the torque distributor housing 66' are four bevel gears 76 with teeth that mesh with external teeth on each of the differentials.

[0144]

[0145] P30966NO00 description and requirements priority

[0146] The angular gears 76 are rotatably attached to the torque distributor housing 66' about rotation bolts 78 about rotation axes C directed radially inwardly into the torque distributor housing 66' normal to the rotation axis A. During "normal" operation with the same output torque on each of the rotation shafts 32, 54 and without twisting in the structure, the two output rotation shafts 32, 54 and the torque distributor housing 66' will rotate at the same speed without the angular gears 76 rotating about their own axis C (although these rotate together with the torque distributor housing 66' which defines the output rotation shaft about the rotation axis A). In use, the torque distributor housing 66' will be connected to an output spline adapter 34 or the like for connection to the generator 12, which is not shown in the figure. If relative twists occur between the output rotation shafts 32, 54, the torque acting on the two differential discs 72, 74 will be different.The angle wheels 76 will then be set in rotation about their own axis C to compensate for inequalities and so that the load is distributed evenly between the two differential discs 72, 74. The torque distributor housing 66' will then, temporarily, be able to have a different rotational speed compared to the output rotation shafts 32, 54 as a result of the imbalances.

[0147]

[0148] In a further alternative embodiment, torque distribution can also be achieved by designing a toothing between the rotating discs and the torque distributor housing with ball surfaces, so that some relative twisting is made possible in the toothed coupling itself. In this way, relative twisting and torque distribution are made possible without the use of external bearings. An example of such a solution with ball surface toothing is shown in Figures 16 and 17.

[0149]

[0150] Fig. 16A-E shows a torque distributor 52 with torque distributor housing 66'' according to the further, alternative embodiment in various perspectives and sections, while Fig. 17A shows an exploded sketch thereof. Fig. 17B shows a section through the line AA from Fig. 17A. Fig. 16A shows the torque distributor seen from one end, while Fig. 16B shows the torque distributor 52 seen from the side. Fig. 16C shows the same torque distributor in perspective, 16D shows a section through the line DD from Fig. 16B, while Fig. 16E shows a section through the line EE from Fig. 16D.

[0151] In the embodiment shown, the first output rotation shaft 32 (partially included in the figure) and the second output rotation shaft (not shown) are rigidly connected to a respective toothed disk 80, 81. The toothed disks 80, 81 are further connected, via ball teething, to a surrounding ball toothed disk 82. The ball toothed disk 82 is formed with two internal ball toothed grooves 84, one for each of the toothed disks 80, 81 with an axial distance between along the axis of rotation A. On its outer side, axially between the two ball toothed grooves 84, the ball toothed disk 82 is formed with a radially protruding ball toothed groove 86. The external ball toothed groove 86 rotates in engagement with an internal

[0152]

[0153] P30966NO00 description and requirements priority

[0154] reversible ball spline groove 88 in the external torque distributor housing 66''. In practice, the various components, which are rotationally coupled with ball splines, are permitted some rotation relative to each other about the axis of rotation A. The embodiment shown in Figs. 16 and 17 provides a three-point ball bearing without the use of external bearings.

[0155]

[0156] Fig. 18 shows a section through an internal torque distributor 43 according to an alternative embodiment. For the sake of clarity, further components included in the gear module 1 are not shown in the figure. Each of the ring gears 28 is in the embodiment formed with an outer gear groove / ring gear 90 which is axially offset relative to the inner gear groove, against which the planet gear carrier 30 (not shown) rotates, and which extends around the outer circumference of the ring gears, so that the two outer gear grooves 90 project axially inwardly towards each other with a distance between. In the gap / distance between the outer gear grooves 90, a plurality of angle wheels 92 are arranged, supported on rotation bolts 94 in the gear module housing 42 about rotation axes D, which are radially on the rotation axis A of the gear module 1. In the illustrated embodiment, eight angle wheels are used (of which three whole and two half are shown in the figure).The teeth on each of the bevel gears 92 are engaged with the outer toothing groove 90 on each of the ring gears 28. In the event of misalignments, as a result of production tolerances and torque loads, some rotation of the two ring gears 28 relative to each other about the axis of rotation A of the gear module 1 is permitted by setting the bevel gears 92 in rotation about their own axis D, so that the internal torque distributor 43 functions as a differential.

[0157]

[0158] It should of course be understood that the groove couplings described above could be replaced with various forms of rotational couplings between rotating parts.

[0159]

[0160] It should be noted that all of the above embodiments illustrate the invention but do not limit it, and those skilled in the art will be able to devise many alternative embodiments without departing from the scope of the appended claims. In the claims, reference numbers in parentheses are not to be construed as limiting.

[0161]

[0162] The use of the verb "to comprise" and its various forms does not exclude the presence of elements or steps not mentioned in the claims. The indefinite articles "a", "an" or "an" preceding an element do not exclude the presence of multiple such elements.

[0163]

[0164] The fact that certain features are recited in mutually different dependent claims does not indicate that a combination of these features cannot be used to advantage.

[0165]

[0166] P30966NO00 description and requirements priority

Claims

Patent claim 1. Gear module (1) comprising:- two parallel planetary gears (22) arranged one after the other along a rotation axis (A) of the gear module (1), each planetary gear comprising a sun gear (24), a ring gear (28) and a set of planet gears (26), the two sets of planet gears (26) being arranged in a common planet gear carrier (30), and the two sun gears (24) being connected together to a common rotation shaft (32) along the rotation axis (A) of the gear module (1);- a gear module housing (42) encircling at least a portion of the two planetary gears (22), characterised in that the gear module (1) further comprises an internal torque distributor (43) connected to each of the ring gears (28) and to the gear module housing (42), such that the two ring gears (28) are allowed to rotate relative to each other about the rotation axis (A) during use.2.A gear module (1) according to claim 1, wherein the internal torque distributor (43) comprises a plurality of shafts (38) which are supported in a ring (28) at each end, and which are supported in the gear module housing (42) between the respective ends.

3. A gear module (1) according to claim 2, wherein the shafts (38) are supported to the ring (28) and to the gear module housing (42) by means of spherical bearings (40).

4. A gear module (1) according to claim 3, wherein the spherical bearings are journal bearings (40). 5.A gear assembly (10) comprising two parallel gear modules (1) according to any one of the preceding claims, wherein the rotary shafts connected to the sun gears (24) in each of the gear modules (1) are output rotary shafts (32, 54), and wherein the output rotary shafts (32, 54) from each gear module (1) are connected together in an external torque distributor (52), such that the two output rotary shafts (32, 54) are allowed to rotate relative to each other, and the planet gear carriers (30) of the two gear modules (1) are together arranged to be connected to an input rotary torque (T).

6. A gear assembly (10) according to claim 5, wherein the planet gear carriers (30) of the two gear modules (1) are connected together by an adapter (48). 7.A gear assembly (10) according to claim 5 or 6, wherein the external torque distributor (52) comprises an external torque distributor housing (66) and rotation discs (58, 60) connected to distal ends of respective rotation shafts (32, 54) from each of the gear modules (1), wherein the external torque distributor (52) further comprises shafts (64) supported with one end in each of the rotation discs (58, 60) and in the P30966NO00 description and claims prio external torque distributor housings (66) between their respective ends, whereby the two output rotation shafts (32, 54) are permitted to rotate relative to each other about the rotation axis (A).

8. The gear assembly (10) of claim 7, wherein the shafts (64) of the external torque distributor (52) are supported to the output rotation discs (58, 60) and to the external torque distributor housing (66) via spherical bearings (40).

9. The gear assembly (10) of claim 8, wherein the spherical bearings are journal bearings (40). 10.A gear assembly (10) according to any one of claims 5-9, wherein the output rotation shaft (32) from one gear module (1) extends internally and concentrically with the output rotation shaft (54) from the other gear module (1) along the axis of rotation (A) towards the external torque distributor (52).

11. A wind turbine (100) comprising a gear module (1) according to any one of claims 1-4, wherein the wind turbine (100) comprises a rotor (14) coupled to the planetary gear carrier (30) of the gear module (1) with an input rotation torque (T), and wherein the wind turbine (100) further comprises a generator (12) coupled to the common rotation shaft (32).

12. A wind turbine (100) comprising a gear assembly (10) according to any one of claims 5-10, wherein the wind turbine (100) comprises a rotor (14) coupled to the planetary gear carriers (30) with an input rotational torque (T), and wherein the wind turbine (100) further comprises a generator (12) coupled to the external torque distributor (52).13.Wind turbine (100) according to claim 11 or 12, wherein the wind turbine further comprises a torque absorber (50) connecting the gear module housing(s) (42) to a wind turbine foundation, such as e.g. a platform (6) on top of a wind turbine column (2).

14. Wind turbine (100) according to claim 13, wherein the torque absorber (50) is a hydraulic cylinder.P30966NO00 description and claims prio.