DESC:FIELD
The present disclosure relates to structures for removal and installation of components within a nacelle of wind turbines.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The subject matter described herein relates generally to wind turbines and a wind turbine nacelle positioned on top of the tower. Whilst the rotor configuration of large wind turbines as three composite blades in upwind attitude with full span pitch control has consolidated in the past years, there is increasing variety in current drive train arrangements. Specifically, a wind turbine rotor has a number of wind turbine blades connected to the nacelle through an integral drive train incorporating rotor shaft and gearbox as a single unit. This gives the advantage of lower weight and better flow of forces. The energy in the wind turns two or three propeller-like blades around a rotor and rotates the shaft, thereby driving the generator to generate electricity to be supplied to a utility grid. Typically, a generator with gear box or a permanent magnet generator is operatively disposed in the nacelle and is configured to generate electricity.
However, non-torsional loads partially transmit from the rotor to the gearbox, thereby resulting in a reduced gearbox life or failures or major breakdowns. Similarly, in the case of permanent magnet generators, the wind speed, turbulence and gust lower reliability of wind turbine blade, pitch and mechanical drive train, grid failure whereas temperature and humidity affect electrical components rather than mechanical ones. In the past, weight has always increased disproportionately to performance due to the huge amount of copper used for the generator. Nearly all of the new gearless concepts on the market is therefore based on external-pole rotors and permanent magnet synchronous generators.
Hence, the operational maintenance of these wind turbines often requires the use of large corrective actions such as construction crane in order to repair or replace the heavy gearbox or the permanent magnet generators in the nacelle. However, due to undulating terrain conditions and height of the tower, use of such heavy-duty cranes is difficult and increases the maintenance cost.
Therefore, there is felt a need of a structure that is portable and that alleviates the aforementioned drawbacks of the conventional arrangements.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine.
Another object of present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine that is rigid.
Another object of the present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine that eliminates use of large and heavy-duty cranes.
Still another object of the present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine that is applicable for wind turbine towers located at on-shore, offshore and seashore.
Yet another object of the present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine that is applicable to all classes and types of nacelles of wind turbines.
Still yet another object of the present disclosure is to provide a portable structure for removal and installation of components within a nacelle of wind turbine that is applicable to all types of terrains.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure envisages a portable structure for removal and installation of components within a nacelle of a wind turbine. The structure comprises a first frame, a second frame, a plurality of first members, a guider having first pulleys, second pulleys, a third pulley, a lifting jig, a fourth pulley, and damping members. The first frame and the second frame configured to be detachably mounted on a nacelle frame. The operative bottom end of each of the frames is configured to be pivotally connected to the nacelle frame. The plurality of first members is configured to be horizontally disposed between the frames. The guider having first pulleys mounted at lower portion of at least one frame. The second pulleys are configured to be mounted on an operative intermediate portion of the frames. The third pulley is configured to be mounted an operative top portion of the frames. The lifting jig is configured to be coupled to a component to be lowered or raised. The fourth pulley is coupled with the lifting jig. The fourth pulley is configured to receive lifting line from the third pulley and form gun tackle arrangement between the third pulley and the fourth pulley. The plurality of damping elements is configured to be attached between the frames and the nacelle frame respectively. The damping elements are further configured to dampen load of the component subjected to the frames during raising and lowering of a component of the nacelle, thereby facilitating smooth lowering and raising of a component from the nacelle.
In an embodiment, the wire rope is configured to pass through a winch disposed on ground towards a tower bottom pulley coupled to the tower bottom and then towards the pulleys disposed on the frames.
In an embodiment, mount frames are detachably mounted on nacelle frame and the structure is detachably mounted on main frames.
In an embodiment, the each of the frames is formed of a first segment, a second segment and a projection.
In an embodiment, the first segment has arcuate shape. In another embodiment, the second segment of first frame and the second segment of the second frame are oblique to each other.
In an embodiment, the projection is extending from the each oblique segment, and the third pulley is operatively disposed between the projections.
In an embodiment, the first frame is replica of the second frame. In an embodiment, the third pulley is operatively disposed between the projections.
In an embodiment, each damping element includes a piston and a cylinder with a damping fluid present in the cylinder.
In an embodiment, the bottom portion each of the frames includes second members attached to the frames in cross-intersection manner.
In an embodiment, stay arms and supporting plates extend from operative top portion of each of the frames. Each of the stay arms and supporting plates include through holes to allow stay links to be tensioned between the stay arms and the support plates to provide strength to the structure during lowering and raising of a component.
In an embodiment, a lock plate is configured to be attached on an operative bottom side of the frames. The lock plate is configured to be connected to the damping elements.
In an embodiment, the damping elements are pivotally coupled to the lock plates.
In an embodiment, the structure is configured to be removably attached to the nacelle frame.
In an embodiment, fasteners are used to attach the structure to the nacelle frame.
In an embodiment, the frames are rigid.
In an embodiment, a holding mechanism is configured to hold a component to be installed or removed. The holding mechanism is further configured to be coupled with the fourth pulley.
In an embodiment, the first pulleys are one-way pulleys. In another embodiment, the second pulleys are one-way pulleys. The third pulley is at least a two-way pulley. In yet another embodiment, the fourth pulley is at least a one-way pulley.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWING
A portable structure of the present disclosure for removal and installation of components within nacelle of a wind turbine will now be described with the help of the accompanying drawing, in which:
FIG. 1 shows a side view of the integral drive train incorporating the rotor shaft and the gearbox as single unit of a robust wind energy plant;
FIG. 2 shows a schematic of bottom bed placed in instead of yaw drive bed;
FIG. 2A shows an isometric view of a yaw motor removed from the nacelle frame;
FIG. 3 shows a schematic view of the structure that is to be used with the wind turbine;
FIG. 3A shows an isometric view of the structure that is to be used with the wind turbine;
FIG. 3B shows a side view of the structure that is directly mounted on the nacelle frame without bottom bed in another embodiement;
FIG. 3C shows an isometric view of the structure, in accordance with another embodiment of the present disclosure with the structure having a monorail that is used above the bottom bed placed in the wind turbine;
FIG. 3D shows a side view of the structure of monorail type that is directly fixed with the holding pinion in the nacelle frame;
FIG. 4 shows an isometric view of a structure mounted on the nacelle along with the winch connected to the wind turbine;
FIG. 5 illustrates the rotor being removed from a gearbox positioned on the nacelle of the wind turbine tower;
FIG. 6 illustrates the procedure for lowering a rotor from the wind turbine tower through a control unit;
FIG. 7 illustrates the support crane lifting tail end of the bottom rotor blade with tag line of the rope attached to the other rotor blades for positioning the rotor into the ground with the support of control unit;
FIG. 7A illustrates the lifting line holding the tail end of the bottom rotor blade through a belt;
FIG. 7B illustrates attachment of the tag line to the rotor blade;
FIG. 7C illustrates progression of winch connections from the bottom of the wind turbine tower;
FIG. 7D illustrates the winch and the counterweights mounted on the ground;
FIG. 8 illustrates positioning of the rotor onto the ground, according to an aspect of the present invention;
FIG. 8A illustrates positioning of the rotor into a rotor stand, for the rotor shown in Fig.8;
FIG. 9 illustrates the lifting jig assembled onto the gearbox in the nacelle of wind turbine through winch controls;
FIG. 10 illustrates dismantling of a gearbox from the nacelle that is ready for getting lowered;
FIG. 11 illustrates the procedure for lowering the gearbox from a wind turbine nacelle by tagline;
FIG. 12 shows a schematic of a gearless wind turbine having a permanent magnet generator for a wind energy plant;
FIG. 13 shows a cross sectional view of the structure used with the gearless wind turbine plant, in accordance with another embodiment of the present disclosure;
FIG. 14 shows a side view of the structure of the Fig. 13 disposed inside the nacelle while the rotor is being dismantled from a permanent magnet generator of the wind turbine;
FIG. 15 illustrates the support crane lifting tail end of the bottom rotor blade, tag line of the rope attached to the other rotor blades for repositioning the rotor from a vertical to a horizontal position into the ground with the support of winch;
FIG. 16 illustrates horizontal positioning of the rotor onto the ground, according to an aspect of the present invention;
FIG. 17 illustrates a lifting beam assembled onto the permanent magnet generator in the nacelle of wind turbine with the help of winch controls; and
FIG. 18 illustrates the procedure for lowering the permanent magnet generator from a wind turbine nacelle through a winch and the structure.
LIST OF REFERENCE NUMERALS
11 – ground
12 – tower
13 – nacelle
14 – nacelle cover
15 – nacelle frame
16 – rotor
17 – blade
17a – adjacent blade
17b – bottom blade
18 – pitch system
19 – gearbox
20 – noise decoupling
21 – yaw drive
22 – generator
23 – composite disc coupling
24 – brake
25 – cooler
26 – hydraulic unit
27 – holding pinion
28 – structure
29 – bottom bed
30 – connecting beam-1
31 – connecting beam-2
32,33 – frame
34,35 – members
36 – stay arm
37,38 – stay links
39 – lock plate
40 – supporting plate
41 – stiffener
42 – pulley block
43 – bottom pulley
44a, 44b – first pulleys
45a, 45b – second pulleys
46 – third pulley
47 – fourth pulley
48 – holding mechanism
49 – actuator
50 – tip sock
51 – web belt
52 – main belt
53 – man-basket
54 – sky-lift
55 – lifting jig
56 – winch
57 – wire rope
58 – counterweight
59 – control panel
60 – stud/bolt/pin & nut
61 – tagline
62 – crane
63 – work force
64 – bottom jig
65 – rotor stand
66 – hydraulic unit
67 – pinion block
68 – bottom pipe
69 – top pipe
70 – first column
71 – second column
72 – first h-beam
73 – second h-beam
74 – shackle
75 – lifting beam
76 – anchorage point
77 – leg post
78 – cross beam
79 – monorail
80 – guider
100 – wind turbine
DETAILED DESCRIPTION
Embodiments, of the present disclosure, will now be described with reference to the accompanying drawing.
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a”, "an", and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises", "comprising", “including”, and “having” are open ended transitional phrases and therefore specify the presence of stated features, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, operations, elements, components, and/or groups thereof.
When an element is referred to as being "mounted on", “engaged to”, "connected to", or "coupled to" another element, it may be directly on, engaged, connected or coupled to the other element. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed elements.
Terms such as “inner”, “outer”, "beneath", "below", "lower", "above", "upper", and the like, may be used in the present disclosure to describe relationships between different elements as depicted from the figures.
Typically, a nacelle sits atop the tower and contains a hub, rotor, gearbox, generator, inverters, hydraulics, bearings, low- and high-speed shafts and mechanical brakes. Some nacelles are larger than a house and for a 1.5 MW geared turbine, can weigh more than 4.5 tons. A nacelle cover is mounted on the bed plate of the turbine. The nacelle cover protects hub, rotor, gearbox, generator, inverters, hydraulics, bearings, low- and high-speed shafts and mechanical brakes. This makes nacelle crucial part of wind turbine tower.
At some wind projects, up to half of all components present inside the nacelle such as gearboxes fail within a few years. The target service life of the typical wind turbine is usually about 100 million main-shaft revolutions over 20 years, but most turbines never survive that long without problems. There are several reasons for this, including the relative newness of the industry, the rapid evolution of turbines to extra-large sizes, poor understanding of turbine loads, and an emerging (and largely unexplained) failure mode in turbine bearings called axial cracking. In order to make repairs, crews must either climb the tower and work at those elevations in conditions that are windy or have special cranes transported to the remote location to enable components to be removed and replaced from the turbine is most difficult.
The present disclosure therefore envisages a portable structure for removing and installing a components within a nacelle of wind turbine. The portable structure (herein after referred to as “structure 28”) is now described with reference to Figure 3 through Figure 18.
In an embodiment, the structure 100 is in the form of a robust construction and used for removal and installation of rotor and the integral drive trains.
In another embodiment, the structure 28 is in the form of a solid structure for the removal and installation of rotor connected with the gearless drive i.e. permanent magnet generator.
As shown in FIG. 1 depicts top of a tower 12 mounted with a nacelle 13 in which the main components of the wind turbine 100 are housed, such as a controller, the gearbox 19, the generator 22, and shafts. The nacelle 13 and the gearbox 19 provide means of transmitting the static and dynamic loads from the rotor 16 into the tower 12. The tower 12 transmits these forces into the ground 11. The rotation of the nacelle 13 is functioned with a single large slewing type bearing which has gear teeth integrally cut into either the inner or the outer race. A yaw system including a yaw drive unit 21, a yaw slew ring, and a yaw brake facilitates slewing of the nacelle 13 as per the wind direction. The yaw system is circumferentially disposed on a top side of the tower 12. The yaw system includes a four-gear motor with a pinion gear at both a front and a back side. A hydraulic power unit 26 of the yaw drive unit 21 controls the braking of the yawing movement of the nacelle 13, and to activate the brake calipers when necessary during turbine service activities.
As shown in the FIG. 1 the rotor 16 supported by a rotor bearing is integrated into the first stage of the gearbox 19, a nacelle frame 15 and the nacelle 13. The gearbox 19 and the nacelle frame 15 constructed as a unified load carrying structure between rotor 16 and tower 12. The drive train integrates with rotor shaft through the gearbox 19 with two or three stages having combinations of planetary and parallel stages. Further, the high-speed drive train connects the output shaft of the gear box 19 to the input shaft of the generator 22 through a composite coupling. Adjacent to the composite coupling, a rotor brake 24 attached to the high-speed shaft as a preventive measure in cases of extreme incident loads. Emergency stops are provided where the rotor 16 has to be controlled from full load operation or overspeed or abnormal operation.
As shown in the FIG. 1, the rotor 16 and the nacelle 13 positioned opposite to the wind direction, and the rotor brake 24 is applied to stop yaw movements arising from the aerodynamic loads. The position of the rotor 16 is adjusted in the form of the english alphabet “Y” and the rotor brake 24 is applied to prevent pitching of a blade 17. In a next step, the rotor brake 24 and the brake in the high-speed shaft are applied. A hydraulic or pneumatic fluid within a closed circle that is set under pressure by a hydraulic pump or a compressor does the transmission and control of brake forces. The rotor brake 24 also includes mechanical brakes having friction pads on a disc.
In a further step, appropriate tools are used to disassemble the couplings 23, the cooler 25 and the associated piping is attached with suitable slings or belts. The slings or belts are further attached to a machine hoist and the coupling 23, the cooler 25 and the associated piping is transported to a rear side of the nacelle 13. The other components of the yaw drive system 21 is disassembled from the nacelle 13 and are securely positioned in the nacelle frame 15 with the support of suitable tools.
In a next step, the nacelle cover 14 is removed to gain access to the components of the wind turbine 100 for performing a large corrective action on the components of the wind turbine 100. The required relative movements of the components of the nacelle 13 are accomplished by rollers and linear actuators 49 or any other motors. The components of the nacelle 13 are moved at least halfway towards the rear side of the nacelle 13. In an embodiment, the actuators 49 are driven electrically. In another embodiment, the actuators 49 are driven hydraulically. In yet another embodiment, the actuators 49 are driven pneumatically. In still another embodiment, the actuators 49 are manually driven.
As shown in the FIG. 2-2A the holding pinion 27 is mounted to the yaw motor mount bed. The step of flange of the holding pinion 27 is complimentary to the step of the flange of the yaw motor mount bed. The top of the flange of the holding pinion 27 has multiple slot holes that are distributed in an equally spaced pattern along the circumference. In particular, a portion of the holding pinion 27 extends in multiple sides of the yaw motor mount bed in a vertical direction from the nacelle 13. The bottom bed holes match with the position of holding pinion 27 to allow fastener tightening.
The body of bottom bed shape resembles the English alphabet “C” which acts as clamps for holding the nacelle frame 15 on multiple sides, in order to enter the jack bolts or jack screws. The jack bolts are long stud bolts 60 that fasten the nacelle frame 15 or the jack into position. Thereby, an effective holding function or additional safety controls is realized.
A connecting beam 30 having I cross section is mounted above the bottom bed 29 from the front side to the rear side in a left-hand side of the nacelle 13. Another connection beam 31 having I cross section is constructed on a right-hand side of the nacelle 13. In particular, the extent may increase upon other assemblies in connecting beams 30, 31 having holes provided thereon.
In a further next step, as shown in the FIG. 2A the yaw motor is removed from the nacelle frame 14, the holding pinion 27 is adapted to the yaw motor bed 29.
FIG. 3 depicts a side view of a portable structure 28, which is detachably fixed inside the nacelle 13. The structure 28 comprises a first frame 32, a second frame 33, a plurality of first members 34, first pulleys 44a, 44b, second pulleys 45a, 45b, a third pulley 46, a lifting jig 55, a fourth pulley 47, and damping members 49A, 49B.
The structure 28 also includes a holding mechanism 48 which is used to hold the component to be installed or removed in similar manner to lifting jig 55. The holding mechanism 48 is further configured to be coupled with the fourth pulley 47.
The frames 32, 33 are constructed on an operative left side and an operative right side of the structure 28. Some of the members 34 are configured to be connected in an operative longitudinal direction whereas the other members 35 are configured to be connected in an operative transverse direction. Some of the members of the frames 32, 33 are configured to be attached to each other in spaced apart manner using first members 34 (FIG. 3A). In an embodiment, each of the frames 32, 33 is formed of a first segment I, a second segment II and a projection III. In an embodiment, the first segment I is in the form of summit curve. In another embodiment, the second segment II of first frame 32 is oblique to the second segment II of the second frame 33. In an embodiment, the projection III is extending from the each oblique segment, and the third pulley 47 is operatively disposed between the projections III.
The structure 28 further includes at least one stiffness plate 41 configured to join members of the frames 32, 33 having an acute angle therein between to increase the strength of the structure 28. At least one pair of supporting plates 40 are used to maintain perpendicularity of the members. The members 34 are oriented in the transverse direction and the members 35 are oriented at angles to the main frames 32, 33 as well as to the members 34 oriented in the transverse direction. In an embodiment, the bottom portion each of the frames 32, 33 includes second members 35 attached to the frames 32, 33 in cross-intersection manner. A pair of stay arms 36 is configured on the frames 32, 33 to extend in an operative top direction to hold a stay link 37 provided between the frames 32, 33 and the stay arm 36. Another stay link 38 is provided between the frames 32, 33 and the stay arm 36. The frames 32, 33 are constructed as a mirror replica of each other.
The frames 32, 33 are in the form of a summit curve with the stay arms 36 and ribs 41 constructed at an operative top side of the structure 28 and a lock plate 39 at an operative bottom side of the structure 28. A plurality of pins 60 are provided for connection between the members of the structure 28 by matching the holes in the supporting plate 40 and the members 34, 35.
A pulley block 42 is provided between the frames 32, 33 of the structure 28. A fixed pulley 46 is mounted on the pulley block 42 to facilitate the hoisting operation (i.e. raising and lowering) of a component such as rotor 16 and the gearbox 19. A wire rope 57 (hereinafter also referred to as lifting line 57) is configured to pass over the fixed pulley 46. The fixed pulley 46 is configured to be assembled with the pulley block 42 on additional shafts to provide necessary supports to the fixed pulley 46. The frames 32, 33 are used to assemble and dismantle the yaw motors 21. As shown in the Figures 1-3A, the two-yaw motors 21 are constructed towards the operative rear side while the hydraulic cylinder 49 is attached towards the operative front side of the structure 28. The hydraulic cylinder 49 connects to the structure 28 through the lock plate 39. The hydraulic cylinder facilitates displacement of the frames 32,33 of the robust structure 28.
In another embodiment as shown in the FIG. 3B a customized anchorage part 76 is used to secure the hydraulic cylinder 76 to the frames 32, 33 with a high grade pin 60. The anchorage part 76 is in the form of two plates having a base that is used for fixing above the holding pinion 27.
In another embodiment as shown in the FIG.3C, the structure 28 is configured to extend from the bottom bed assembly. The structure 28 includes leg posts 77 extending the operative top side in the front and the rear side of the yaw drive 21. The cross beams 78 are connected to the leg posts 77 towards the operative top side. Fasteners secure the connection between the cross beams 78 and the leg posts 77. The cross beams 78 are fabricated with at least one flange along its length to make a fastening joint with the leg posts 77 to resist bending loads. A pair of monorails 79 is configured on the operative top side of the structure 28 to match the flanges of the cross beams 78. Cross supports (not shown in figure) are configured to connect the leg posts 77.
In another embodiment, as shown in the FIG.3D a side view of the FIG 3C is shown. The leg post 77 has one flange having a circular shape of a suitable size fastened to the holding pinion 27 in all four corners of the structure 28.
As illustrated in the FIG. 4 and the FIG.5 a lifting line 57 is configured to be routed from a winch 56 mounted in the ground 11 near the tower 12. A plurality of pulleys 43, 44a, 44b, 45a, 45b, 46, and 47 is configured in between the winch 56 and the wind turbine components. In an embodiment, the wire rope 57 is configured to pass through a winch 56 disposed on ground 11 towards a tower bottom pulley 43 coupled to the tower bottom and then towards the pulleys 44a, 44b, 45a, 45b, 46, 47 and back to 46 disposed on the frames 32, 33. The pulleys 43, 44a, 44b, 45a, 45b, 46, and 47 facilitate routing of the lifting line 57 which is in the form of a high strength wire rope that can withstand large loads attached thereto. The bottom pulley 43 (as shown in the Figure 7C) is coupled at the bottom end of the wind tower 12. A jig 64 clamped at the bottom of the wind tower 12 facilitates mounting of the bottom pulley 43 thereon. As shown in the Figure 5, the first pulleys 44a, 44b are mounted on an operative lower side of the structure 28 on the guider 80. The second pulleys 45a, 45b are mounted on an operative intermediate portion of the frames 32, 33. The third pulley 46 is a fixed pulley mounted at the operative top side of the structure 28. The fourth pulley 47, which is a movable pulley overhangs from the structure 28. A wedge socket arrangement is provided at the end of the fourth pulley 47.
In an embodiment, the first pulleys 44a, 44b are one-way pulleys. In another embodiment, the second pulleys 45a, 45b are one-way pulleys. The third pulley 46 is at least a two-way pulley. In yet another embodiment, the fourth pulley 47 is at least a one-way pulley.
As shown in the FIG. 5, the rotor 16 is lifted a certain distance in the operative vertical direction towards the lifting line 57. The weight of the rotor 16 relieves the joint forces between the rotor 16 and the gear box 19. The fasteners 60 are then taken out from the joint to disengage the rotor 16 completely. The fasteners 60 are loosened in star-pattern to distribute joint forces equally between all sides of the joint. As shown in the Figure 8A, a rotor stand 65 is configured to be attached to the rotor 16 to facilitate placement of the rotor 16 on the ground 11 thereby avoiding contact of the rotor 16 surfaces with the ground 11.
As shown in the Fig. 7, a workforce 63 assists in lowering of the rotor 16 from nacelle 13. The workforce 63 communicates merely during the lowering operation and cross checks the winch 56, the lifting line 57, the structure 28, the damping members 49A, 49B, the pulleys 43-47, and taglines 61 are in good working condition. The workforce 63 facilitates a controlled descend of the rotor 16. The fasteners are released from the rotor 16. During the descend of the rotor 16 the workforce 63 ensure the rotor 16 does not destabilize due to the incident wind loads.
As shown in the Fig.7, the rotor bottom blade 17b reaches the desired position from the ground 11, then the workforce 63 engage to hold the position of the bottom blade 17b through a crane 62 for changing the orientation of the rotor 16 from a vertical to a horizontal position. The angular orientation of the rotor 16 is changed during its descend such that the rotor 16 is positioned parallel to the ground 11. The taglines 61 control the positioning of the rotor 16 such that an appropriate distance is maintained from the tower 12.
As shown in the Fig. 7A, a blade tip sock 50 is attached to the blade 17b for obtaining a firm grip thus facilitating maneuverability in changing from the vertical position to the horizontal position by using a telescopic crane 62. The blade tip socks 50 are made of polyester which has high strength/load capacity, low shrinkage and easy to hold its shape. The blade tip sock 50 is designed to carry seven times the weight of a blade 17 which is customized according to the profile of the blade 17. Herewith the work force 63 assembles blade tip socks 50 attached in appropriate distance from a tip of the blade 17b.
The telescopic crane 62 boom extends carries the blade tip sock 50 on a blade 17 along with the workforce 63 through a manbasket 53 provided on the crane 62. A web-belt 51 is attached to the blade tip sock 50 by the workforce 63, as shown in figure.7A. The web belt 51 is hitched into a holding mechanism 48 attached to the fourth pulley 47.
As illustrated in the Fig. 7B, at least one tagline 61 is tied-up with both adjacent blades 17a individually with the help of a sky-lift 54 and the other end of the rope is dropped into the ground 11, thus the tagline 61 leads to the respective positions of the rotor 16. The turbine is positioned to oppose the wind direction to avoid swaying of the rotor 16 and the blades 17. This is done by manual means or hydraulic means or electric means. At least one lock is provided on the hub of the rotor 16 to avoid any further shaking or rotation movement from wind load. The lock facilitates as a safety lock.
The sky-lift 54 facilitates attachment of the lift-line 57 to the rotor 16 and its ends are dropped onto the ground 11. The role of sky lift 54 is to ascend or descend the lift line 57 with at least one workforce 63 to a desired height to reach upto the hub of the rotor 16. The workforce 63 attaches the tagline 61 of a receptacle over the appropriate distance from the both adjacent blade as shown in Fig. 7B and descending the sky-lift 54 in a safe manner. Meanwhile the workforce 63 continues the dismantling of other components of the wind turbine 100.
As illustrated in the Fig. 7C the workforce 63 assemble the tower bottom jig 64. The tower bottom jig 64 is circular in shape resembling a ring that is removably clamped or attached to the tower bottom of the wind turbine 100.
The winch 6456 includes pulling devices such as a rope wound around a horizontal drum turned typically by a motor and controlled by a drive system. The bearing capacity of the winch 64 56 is governed by the hub height and weight of the rotor 16, and the gearbox 19. The winch 56 is mounted on a concrete platform constructed on the ground 11. The counterweight 58 provides stability and supports the winch 56. The main consideration is selection of the counter weight 58 based on a load factor for lifting line 57.
In accordance with an embodiment Fig.8, to alter the rotor 16 from its vertical position to horizontal position after reaches the specific height from the ground level, the manual force 63 uses the telescopic crane 62 to assemble the tip socks 50 on the bottom blade 17b. This alteration of rotor position includes the telescopic crane 62 operation of boom up and down; swing; extension and retraction of the boom. The telescopic crane 62 hauls the bottom blade 17b with assembled tip socks 50 and operates the winch 56 to release the lifting line 57 with downward descend causing to alter the position of the rotor 16 keeping it horizontally along the ground level 11. In order to alter the rotor position, the manual force 63 keeps the adjacent blade 17a in far from the tower 12 through the taglines 61. At the time of the descend of the rotor 16, the required distance is maintained between the rotor 16 and the tower 12 wherein conical shape from top to bottom is maintained.
The winch 56 gradually releases the lifting line 57 and the component load is attached to the holding mechanism 48. In another embodiment, the manual force 63 guides the rotor 16 through the tag lines 61 which connect with the both adjacent blades 17a. After the rotor 16 reaching the horizontal position, the movement of the telescopic crane 62 is terminated and the boom is retracted. The downward descend of the component by the winch 56 is carried out at a rate which is directly proportional to the rate of retraction of the boom of the crane 62.
As shown in the Fig.8A, after the rotor 16 reach a desired height it remains in position to attach with the rotor stand 65. The desired height is one in which the rotor 16 is in-line with the rotor stand 65. The holes on the rotor stand 65 align with holes of the rotor 16 with the axis of the rotor 16 oriented in the vertical direction. Once, the rotor 16 achieves its desired position, the rotor 16 and the telescopic crane 62 are lower to cause touching of the rotor stand 65 onto the ground 11.
This connection is secured with fastening elements by providing specific amount of torque either through mechanical, electrical or hydraulic tools. After assembling the rotor 16 on the rotor stand 65, the holding mechanism 48 and the blade tip sock 50 is released from each of the blades 17. Typically, the holding mechanism 48 includes at least one of a main belt 52 with moving pulley 47 or the jig 55 with the moving pulley 47 that assembles on the adjacent blades 17a. The blade tip socks 50 is attached to the web belt 51 for lowering of the bottom blade 17b.
As shown in the Fig. 9 the counterweight 58 is lifted upto the nacelle 13 and configured to be attached to the front portion of the gearbox 19. This is done to allow a controlled descend of the gearbox 19, as the attached counterweight 58 to the gearbox 19 adjusts the center of gravity of the gearbox 19 so that the gearbox 19 is held in a stable position during the descend.
The counter weight 58 is attached to the gearbox 19 by matching the holes in the gearbox 19 with the provision provide on the counter weight 58. After matching the provision with the hole in the gearbox 19, the workforce 63 fasten the provision with the required tools. In another embodiment, the counter weight 58 is attached to the gearbox 19 through an angular plate. After the counter weight 58 is completely attached to the gearbox 19, the workforce 63 present at the location of the gearbox perform all the necessary checks and establishes communication with the workforce 63 present on the ground 11.
As shown in the Fig. 9 the lifting line 57 is attached to the lifting jig 55 positioned to lift the gearbox 19. The lifting jig 55 is attached to the fourth pulley 47 causing the lifting jig 55 to reach near the nacelle 13. The workforce 63 operates the controls applied for the structure 28 through the damping members 49A, 49B for the frames 32,33 to cause displacement of the frames 32,33 in the operative forward direction. The winch 56 is controlled to raise or lower the lifting line 57 simultaneously with the operation of the damping members 49A, 49B. This causes the lifting jig 55 to be aligned with the top of the gearbox 19 and thus fasteners 60 are dismantled. The damping elements 49A, 49B, the stay arms 36, projections 40 and stay links 37, 38 are further configured to dampen load of the component subjected to the frames 32, 33 during raising and lowering of a component of the nacelle 13, thereby facilitating smooth lowering and raising of a component from the nacelle 13.
As shown in the Fig. 10, the lifting jig 55 is attached to the gearbox 19 through the structure 28 with the lifting line 57 passing over the frames 32, 33 and positioned in a straight path between the gearbox 19 and the structure 28 by means of the hydraulic cylinder 49. To dismantle the gearbox 19 from its bed, the winch 56 is wound to cause tension buildup in the lift line 57. This facilitates ease in loosening the fasteners between the gearbox 19 joint. Further winding of the winch 56 facilitates ease of dismantling of the gearbox 19 as it is lifted of its constraints.
Once the gearbox 19 is raised enough from the fastener provisions, retraction of the hydraulic cylinder 49 results in downward movement of the frames 32, 33 of the structure 28. The movement of the frames 32, 33 in the vertically downward direction facilitates horizontal movement to the gearbox 19 while the pulling operation of the lifting line 57 from the winch 56 results in vertical movement of the gearbox 19. The gearbox 19 is guided along a diagonal path during its dismantling. During this combined operation, the workforce 13 ensures that the gearbox 19 is kept at some distance from the nacelle 13 and its components through audio-visual communication means.
As shown in the Fig.11, a permanent hooking point of the gearbox 19 facilitates ease of dismantling of the gearbox 19. At least one of the tagline 61 use to guide the gearbox 19 during the lowering operation.
The rate of winding or unwinding of the winch 56 is varied to counter the imbalance and instability due to wind loads. The rate of winch 56 operation also depends on the component of the wind turbine 100 being lowered. The workforce 63 guides the taglines 61 attached to the gearbox 19 to control the turn up or rotation against the lifting line 57. The taglines 61 ensure safety while lowering the components of the wind turbine 100. The workforce 63 continues to guide the gearbox 19 by the tagline 61 until it reaches the ground 11.
After lowering of the gear box is completed, the lifting jig 55 is unfastened from the erected gearbox 19. This is followed by de-erection of the gearbox 19 to cause switching from its place with the help of the telescopic crane 62. A replacement gearbox 19 is lifted in a similar fashion as described above. The fasteners 60 are re-installed that were taken down during the dismantling operation of the gearbox 19.
Similar to the gearbox 19, the re-erection of a new or serviced rotor 16 is carried using the lifting jig 55. During re-erection, the fifth pulley 47 is assembled with the holding mechanism 48 that enables to re-erect the rotor 16. Upon confirmation of re-erection of the rotor 16, the holding mechanism 48 is detached from the rotor 16.
Similarly, the structure 28 is disassembled and lowered to the ground 11. The workforce 63 assembles all the components in the nacelle 13 that were dismantled during the robust structure 28 assembly including the assembly of yaw motor 21, the hydraulic unit 26, the cooling unit 25 and other subassemblies.
In an alternate embodiment as shown in the FIG. 12 through FIG. 18, the structure 28 is in the form of solid structure and is used for installing and removal of components of a gearless wind turbine 100 is shown that includes permanent magnets or electrically excited synchronous generator 22.
According to embodiment of FIG.12, the type of a nacelle 13 is round type or an oval shaped outer shell. The rotor 16 is directly attached to the generator 22. Alternatively, the rotor 16 is directly attached to the permanent magnet synchronous generator 22 or an electrically excited synchronous generator 22 and then further connected in nacelle 13. Thus, the hydraulic unit 66, an electrical cabinet and the nacelle frame 15 are positioned in series. These components are made up of cast steel, further it comprises the main structure houses the nacelle 13, in order to inside the nacelle 13; the central frame is placed by one service crane and three yaw motors 21 followed by two cooler motors are purposefully to functioned the external and internal cooling circuit as required usage to heat dissipates from the generator 22 and further it substantially placed a heat exchanger at rear side and finally wind measurements device is being placed at top of nacelle 13 and also arranged the obstruction lights in same location expect from these, all others are fully equipped with nacelle 13 which constructs by an fiber reinforce plastic.
The generator 22 is arranged to be connected to the nacelle 13 taking into consideration the taper angle while assembling the generator 22. The generator 22 operates at the same speed as the rotor 16 and therefore the rotor shaft is attached directly to the generator 22. The permanent magnets are fitted to the outer cover of the rotor 16 which facilitates reducing the heat losses in the generator 22 and providing for simple and efficient cooling. The shape of the external rotor 16 supports a compact design and can be achieved on a reduced surface of the generator 22, and an active air-cooling system inside a wind turbine 100 nacelle 13 is constructed. An air-to- air heat exchanger or any other type of exchanger for managing heat in the generator 22 is incorporated.
As shown in the FIG.13, the workforce 63 using nacelle hoist lifts and places the fabricated parts one by one into position that are connected by the fasteners 60. The structure 28 includes a bottom pipe 68, a top pipe 69, a pinion block 67, H-beams (72, 73), columns (70, 71) and cross bracings are provided with the hole provisions for assembling the square flange in all pipes that are connected with the stiffener 41 for supporting the loads. The work force 63 dismantles two yaw drive motors 21 towards the operative rear side and one yaw drive motor 21 in the operative right side towards an operative front side of the nacelle 13.
Typically, the bottom pipe 68 is fastened to the bottom bed plate or yaw bed towards an operative front side of the operative left side. The same procedure is followed to fixing right side and rear side of the nacelle 13, According to receptacle of again fixing the top pipe 69 to lock the fasteners from the bottom pipe 68 square flange on front & rear side of top pipes 69. Each of the top pipes 69 supports are also preferably H-beams (72, 73) and columns (70, 71) are disposed in horizontal alignment and in end to end relationship with respect to their supporting top pipes 69, in these H-beams (72, 73) consists of hook on both ends at top and square flange on bottom of beam ends. Further, the first H-beam 72 is assembled on a front side of top pipes flange to rear side of top pipe flanges in left hand side and the second H-beam 73 assemble on a front side of top pipes flange on rear side of nacelle top pipe flange in right hand side with help using fasteners. The fasteners lock H-beams (72, 73) with top pipe flanges.
Further, the front side of first H-beam 72 & second H-beam 73 the actuator assembly 49 and follows back side the solid steel structure 28 assemblies and further follows the first column 70 and second column 71 assemble in between the H-beams (72, 73) which it means assemble perpendicular to the H-beams (72, 73). The first column 70 being assembled on inner of the H-beam (72, 73) from left hand side to right hand side of rear side with locking of fasteners. The second column 71 follows the same assemble process on H-beams (72, 73) in front side.
In addition to that, at least one stiffener 41 is provided on the side of minimum angle between all the pipes to increase the strength by means of stress concentration factor. The cross bracing with the supporting plate 40 can be followed to hold with use of fasteners 60 to lock a cross-bracing.
According to the present embodiment, the top of the solid structure comprises a first frame 32 and damping members 49A, 49B are placed in left hand side and right-hand side provides on front side correspondingly. The first frame 32 is a curvy shape while in being locked in top of first H-beam 72, whereas connected by fasteners said as pivot mechanism type on rear side of nacelle 13 which it further continues to lock the damping member 49A, 49B on H-first beam 72 front side. The first frame 32 construction and joints is a mirror replicate to second main frame 33.
In addition to that, at least some diagonal supports provided on the side of minimum angle in between all the two elements to increase the strength by means of stress concentration factor, hence the first frame 32 and the second frame 33 consists of at least one pair of supporting plates 40 which are used to kept perpendicular in direction to elements accordingly with at least a hole in to match the cross supports 34 and X-supports 35. The connecting beam 30 has a stay arm 36 to hold the stay links 37, 38, this implies that the first stay link 37 and second stay link 38 is provided which is a mirror replicate to second main frames 33.
Followed by, assembling the pulley block 42 between the main frames in the solid steel structure 28 which is used to bear the fixed pulley 46 throughout the operation of rising and lowering of the rotor 16 and generator 22 with the lifting line 57 pass over it. The fixed pulley 46 is assembled with the pulley block 42 with additional shafts to provide necessary supports to the fixed pulley 46.
In order to illustrate the assembling of the structure 28 into the nacelle 13, the workforce 63 assembles circular in shape of rings like a structure 28 is clamped through tower bottom and fastened with use of bolts and pins 60. Then lock a one-way bottom pulley 43 and first pulleys 44a, 44b are located at the rear side of the structure 28 and guide/ second pulleys 45a, 45b assembled at center of the frames 32, 33. Further, third/ fixed pulley 46 assembled on top of the solid steel structure 28, finally it ends with movable pulley 47 to lowering & rising of rotor 16 and generator 22 with help of using lifting-line 57 travelling through all the pulleys.
As shown in the FIG.14 shows the rotor 16 may be regarded as being positioned at opposing sides of the nacelle 13, along an axial direction with an arrangement of using the customized designed solid steel structure 28 and its operative drive by winch 56 and the actuator 49 placed in the nacelle 13. The workforce 63 cross checks the arrangement and provides the operative signal through the winch 56, the lifting line 57, the solid steel structure 28, the pulleys 43,44a, 44b, 45a, 45b, 46, 47 and the tagline 61. The workforce 63 pulls the two taglines 61 to control the rotor 16 concurrently to lift some inches from rotor 16 on solid steel structure 28 by using a movable pulley with the help of using lifting line 57 from the winch 56.
Further, the rotor 16 is released to extend damping members 49A, 49B downwards. The structure 28 and the damping members 49A, 49B arm position is extended due to rotor 16 reaches right position to comes out from the generator shaft, thereby releasing the balance fasteners 60 in clamps with appropriate suitable tools in rotor 16 with continuously all the fasteners 60 are released from rotor 16. The rotor 16 is completely removed from the generator 22 with the help of winch lifting-line 57 to downwards descends, hence its ready positioning for de-erecting the wind turbine rotor 16. Further continuous operation of the winch 56, the lifting line 57 starts travelling to descend the rotor 16 towards ground 11, in order to that simultaneously the work force 63 prepares and positions telescopic boom lift of crane to lock the bottom blade in the rotor 16.
As shown in the FIG. 15, the side views of the wind turbine 100 depicts that the rotor 16 completely reaches the ground 11 from some height. Whereas, the lifting line 57 stops the operation and the tagline 61 and holds in the same position. Further, the ground workforce 63 assembles a tip sock 50 having a U-shaped leading edge and a V-guard trailing edge protector combination of polyester web sling to fix an appropriate some distance from a bottom blade 17b may be an lifting point and a supports of arranged to be crane boom lifts with help of workforce 63 to raising blade tip socks 50 towards on a blade lifting point and fix it the required positioned and then fix the web belt 51 above the tip socks 50 to make choker hitch for changes the orientation of rotor 16 in vertical position to horizontal position and operates to lowering the rotor 16, meanwhile the crane boom being lift.
Hence, the orientation of rotor 16 may change the angle representatively as travelled from 90°, 135° and 180° while it means according to an embodiment of rotor position includes the mobile crane 62 operation of boom up and down; swing; extraction and contraction; required position can be adjusted or use to haul the bottom blade 17b and the winch releases the lifting line 57 to lowering which causes to alter the rotor 16 and keep it horizontally along the ground level 11. In order to alter the rotor position, the manual force keeps the adjacent blade 17a in safe and far from the turbine tower through the taglines 61.
FIG.16 says the rotor 16 decent, the mobile crane is used to haul the bottom blade 16b by means of complete controls of crane 62 for preventing the rotor 16 tends to touch the turbine tower 12, in an embodiment of concurrent operation, the winch lifting line 57 release the load and the manual force 63 guides the rotor 16 through taglines 61 with connect the adjacent blade 17a and after reach horizontal position, the crane ends up its movement and it gradually booms down its length winch 56 continues to release the lifting line 57 in proportional rate of mobile crane 62 booms down, Under the circumstance, the rotor 16 tends to lower in its horizontal position at desired height from the ground level 11. In accordance with an embodiment, after rotor 16 reach it’s a desired height, it remains in position to attach with the rotor stand 65. The desired height is one in which the rotor 16 is in position of in-line with the rotor stand 65 with specific height limitation, gradually release down the rotor 16 with combined operation of the mobile crane 62 and winch 56, the rotor screws are fasten with the holes in the rotor stand 65 as identical. This connection is secure with fastening elements by providing specific amount of torque both through appropriate tool and in one embodiment, after assembling the rotor 16 on its stand 65; position the foam blocks place under the support points of the blades 17 to ensure the blade tip avoid to contact with the ground 11, further which allows to release and removing the winch-lifting line 57 to movable pulley 47 with jig 55 or web belt 51 with tip socks 50 on mobile crane 62 and taglines 61.
FIG. 17 describes operating a winch 56 to release movable pulley 47 via lifting-line; in order to that the movable pulley free from the rotor attachment, subsequently it being move from rotor 16 to attach the designed generator lifting equipment 75 in generator anchorage points 76 provided. To this lifting equipment consists of lifting beam 75 and it’s both end connecting with shackles 74 and slings with hoisting of main belt 52, the main belt 52 may be a polyester or polypropylene or polyamide is using to hold the load as component.
The taglines 61 is attached to the lifting equipment 77 75 for use of guide the lifting device and generator 22, simultaneously operate a winch-lifting line 57 to raising the generator lifting equipment 77 75 and meanwhile workforce 63 guide the taglines 61 controls, the generator lifting equipment 77 75 reaches the nacelle 13, and nacelle team 63 pass the communicate to winch operator to operate a winch-lifting line 57 continuously to moving pulley 47 reach a below some inches from solid steel structure 28 fixed pulley 46 to using a hydraulic movable arm piston retracts or extends to solid steel structure 28 upwards to lock a generator lifting equipment 77 to generator lifting point and also fasten to tie the taglines 61 to the stator shaft flange holes on the right and left side of the generator 22.
In this generator 22 consist of round shape construction and fewer rotating parts like cooling wings, the outer part being as rotor 16 and inner part being as stator.
In a present embodiment FIG.18 says with concurrent operation of customized design solid steel structure 28 provides hydraulic actuator 49 retracts or extracts the solid steel structure 28 functioned in upwards or downwards position, while it means the main frames position is fixed at particular position for generator 22 lowering. Furthermore, the arrangement to be inspected of generator 22 may be regarded as being positioned the solid steel structure 28 on COG (Center of gravity) to the generator anchorage points 76 and follows the lifting line 57 operate to movable pulley 47 movements to raising or lowering some inches from the generator 22 to release the balance fasteners with suitable tools means, while the workforce 63 ensure to final cross-check the winch 56, pulleys, solid steel structure 28, generator lifting equipment 77 75 and taglines 61. To this end, all the fasteners 60 are released from the generator 22 to reach a height from where the lifting line 57 passing over the fixed pulley 46 attached at the top of the solid steel structure 28 towards a movable pulley 47, operate a winch-lifting line 57 to lowering the generator 22 during this process, the workforce 63 being to ensure the wind speed and guide the taglines 61 to lowering the generator 22 from nacelle 13.
Furthermore, the de-erection of the rotor 16 and generator 22 is done in reverse sequence, its assembly is followed by the same method to accomplish and execute re-erection in the same sequence.
The foregoing description of the embodiments has been provided for purposes of illustration and not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization of a portable structure for removal and installation of components within a nacelle of wind turbine, that:
• is rigid;
• eliminates use of large and heavy-duty cranes;
• is applicable for wind turbine towers located at on-shore, off-shore and sea shore;
• is applicable to all classes and types of wind turbines; and
• is applicable to all types of terrains.
The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
The foregoing description of the specific embodiments so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.
Any discussion of materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.
The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.
While considerable emphasis has been placed herein on the components and component parts of the preferred embodiments, it will be appreciated that many embodiments can be made and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. These and other changes in the preferred embodiment as well as other embodiments of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.

,CLAIMS:WE CLAIM:
1. A portable structure (28) for removal and installation of components within a nacelle (13) of wind turbine (100), said structure (28) comprising:
• a first frame (32) and a second frame (33) configured to be detachably mounted on a nacelle frame (15), operative bottom end of each of said frames (32,33) configured to be pivotally connected to said nacelle frame (15);
• a plurality of first members (34) configured to be horizontally disposed between said frames (32,33);
• a guider (80) having first pulleys (44a, 44b) mounted thereon, said guider configured to be operatively mounted at lower portion of at least one of said frames (32, 33);
• second pulleys (45a, 45b) configured to be mounted on an operative intermediate portion of said frames (32, 33);
• a third pulley (46) configured to be mounted an operative top portion of said frames (32, 33);
• a lifting jig (55) configured to be coupled to a component to be lowered or raised;
• a fourth pulley (47) coupled with said jig (55), said fourth pulley (47) configured to receive lifting line from said third pulley (46) and form gun tackle arrangement between said third pulley (46) and said fourth pulley (47); and
• a plurality of damping elements (49A, 49B) configured to be attached between said frames (32, 33) and the nacelle frame (15) respectively, said damping elements (49A, 49B) further configured to dampen load of the component subjected to said frames (32, 33) during raising and lowering of a component of the nacelle (13), thereby facilitating smooth lowering and raising of a component from the nacelle (13).
2. The structure (28) as claimed in claim 1, wherein said wire rope (57) is configured to pass through said winch (56) onto a tower bottom pulley (43) and then towards said pulleys (44a, 44b, 45a, 45b, 46, and 47).
3. The structure (28) as claimed in claim 1, wherein connecting beams (30, 31) are detachably mounted on nacelle frame (15), said structure (28) is detachably mounted on said connecting beams (30, 31).
4. The structure (28) as claimed in claim 1, wherein each of said frames (32, 33) is formed of a first segment (I), a second segment (II), and a projection (III).
5. The structure (28) as claimed in claim 4, wherein said first segment (I) of each of said frames (32, 33) is in the form of summit curve.
6. The structure (28) as claimed in claim 4, wherein said second segment (II) of each of said frames (32, 33) are oblique to each other.
7. The structure (28) as claimed in claim 6, wherein said projection (III) is extending from said each oblique segment, and said third pulley (46) is operatively disposed between said projections (III).
8. The structure (28) as claimed in claim 1, wherein said first frame (32) is replica of said second frame (33).
9. The structure (28) as claimed in claim 1, wherein said third pulley (46) is operatively disposed between the frames (32, 33).
10. The structure (28) as claimed in claim 1, wherein each damping element (49A, 49B) includes a piston and a cylinder with a damping fluid present in the cylinder.
11. The structure (28) as claimed in claim 1, wherein bottom portion of top end of said frames (32, 33) includes second members (35) attached to said frames (32, 33) in transverse manner.
12. The structure (28) as claimed in claim 1, wherein stay arms (36) and supporting plates (40) extend from operative top portion of each of said frames (32, 33), each of said stay arms (36) and supporting plates (40) include through holes to allow stay links (37, 38) to be tensioned between said stay arms (36) and said support plates (40) to provide strength to said structure (28) during lowering and raising of a component.
13. The structure (28) as claimed in claim 1, wherein a lock plate (39) configured to be attached on an operative bottom side of said frames (32, 33), said lock plates (39) is configured to be connected to said damping elements (49A, 49B).
14. The structure (28) as claimed in claim 13, wherein said damping elements (49A, 49B) are pivotally coupled to said lock plates (39).
15. The structure (28) as claimed in claim 1, wherein said structure (28) is configured to be removably attached to said nacelle frame (14) (15).
16. The structure (28) as claimed in claim 16, wherein fasteners are used to attach said structure (28) to said nacelle frame (15).
17. The structure (28) as claimed in claim 1, wherein said frames (32, 33) are rigid.
18. The structure (28) as claimed in claim 1, wherein said lifting jig (55) is raised or lowered upon operation of a ground winch (56) simultaneously with operation of damping members (49A, 49B).
19. The structure (28) as claimed in claim 1, wherein a holding mechanism (48) is configured to hold a component to be installed or removed, said holding mechanism (48) further configured to be coupled with said fourth pulley (47).
20. The structure (28) as claimed in claim 1, wherein said first pulleys (44a, 44b) are one-way pulleys.
21. The structure (28) as claimed in claim 1, wherein said second pulleys (45a, 45b) are one-way pulleys.
22. The structure (28) as claimed in claim 1, wherein said third pulley (46) is at least a two-way pulley.
23. The structure (28) as claimed in claim 1, wherein said fourth pulley (47) is a one-way pulley.
Dated this 27th day of September, 2021

_______________________________
MOHAN RAJKUMAR DEWAN, IN/PA – 25
of R.K.DEWAN & CO.
Authorized Agent of Applicant

TO,
THE CONTROLLER OF PATENTS
THE PATENT OFFICE, AT CHENNAI