FORM 2
THE PATENTS ACT, 1970 (39 of 1970)
AND
THE PATENTS RULES, 2003 COMPLETE SPECIFICATION
(See section 10; rule 13)
1. TITLE OF THE INVENTION
NACELLE FOR A WIND TURBINE HAVING A HUB ENTRY
2. APPLICANT
(a) Name : Suzlon Energy Limited
(b) Nationality ; Indian
(c) Address : Shrimali Society, Near Shri Krishna
Complex, Navrangpura, Ahmedabad 380 009, Gujarat, India
3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
The invention relates to a nacelle having a spinner opening for entering the inside of the spinner from the nacelle arranged beside the nacelle cover interface, wherein the spinner opening is sized such a way to form a maximum opening for a sideway entry between the rotor lock disk and the spinner. Further the invention relates to a wind turbine having said nacelle.
BACKGROUND
Wind turbines are widely known in the prior art. Wind turbines generally comprise a nacelle incorporating different components of a drive train chain, a rotor with one or more rotor blades and different electric components. The nacelle is mounted on a tower. The rotor is connected to a rotor shaft via a hub, on which the rotor blades are mounted.
Wind turbines comprising a nacelle having a hub entry are known from the EP 1 508 692 B1 and EP 2 909 471 B1.
OBJECTS OF THE INVENTION
One object of the present invention is to reduce the influence on the overall size of a spinner and its design and reducing the number of entries or transition tunnels for entering the hub.
A further object of the invention is to provide a wind turbine having said nacelle.
SUMMARY OF THE INVENTION
This object is solved by a nacelle according'to claim 1.

The nacelle has a nacelle cover, which has a nacelle cover interface; a spinner covering a hub, wherein the hub has a rotor lock disk; and a spinner opening for entering the inside of the spinner from the nacelle arranged beside the nacelle cover interface, wherein the spinner opening is sized such a way to form a maximum opening for a sideway entry between the rotor lock disk and the spinner.
Advantageously, the spinner opening is arranged between the spinner and the nacelle cover in an area of the nacelle cover interface. More advantageously, a space between hub and spinner is sized between 550 mm and 650 mm.
An advantage of the present invention is that service personnel could enter the spinner in any position of the rotor blades, especially when one of the rotor blades is in 3 o'clock, 6 o'clock, 9 o'clock or 12 o'clock position, in a front view of the rotor.
A further advantage of the present invention is that service personnel are not restricted in movement between the nacelle and the hub. Especially, the service personnel could carry his tools and equipment for maintenance in the hub area.
A further advantage of the present invention is ease of hub assembly and better access to bolting connection between main shaft and hub.
In one embodiment of the nacelle, the spinner has exactly one spinner opening. This allows an opening for horizontal sideways movement over short distances in upright posture of the service personnel. Furthermore, exactly one spinner opening allows an entry to the spinner in any position of the blades. The spinner opening could be circular or square shaped.

In one embodiment of the nacelle, the spinner opening is circular shaped and has a diameter of less than 4300 mm. This allows a more comfortable entry to the spinner for the service personnel.
In one embodiment of the nacelle, the nacelle cover has a flat nacelle cover landing platform for a service personnel at the nacelle cover interface. Especially, the nacelle cover has a flat nacelle cover landing platform on each side. This allows the service personnel to have a firm stand at the nacelle while entering the spinner. Thus, the safety for the service personnel during the transition is increased.
In one embodiment of the nacelle, the spinner has at least two flat spinner landing platforms for service personnel. This allows the service personnel to have a firm stand at the spinner while entering therein. Thus, the safety for the service personnel is increased. Advantageously, the at least two flat spinner landing platforms are arranged in such a way that a service personnel could enter the spinner when the rotor blade is in a 3 o'clock or in a 6 o'clock position, in a front view of the rotor.
In a further preferred embodiment, the nacelle cover landing platform and one of the at least two flat spinner landing platforms are arranged at the same level. This allows the service personnel to have a firm stand at the nacelle side as at the spinner side, while entering the spinner. Thus, the safety for the service personnel is increased further.
In one embodiment of the nacelle, the rotor lock disk has at least one cut-out, especially two cut-outs, especially three cut-outs, for a larger entry space. This allows increasing the opening size for a more comfortable entering for the service personnel. At the same time, the increased opening size allows to ease the transfer of tools and/or spare parts into the spinner.

In a further preferred embodiment, the rotor lock disk has three cut-outs which are arranged 120° to each other. This allows increasing the opening size when one of the rotor blades is in a 3 o'clock or in a 6 o'clock position, in a front view of the rotor.
In one embodiment of the nacelle, there is arranged an interface cover between nacelle cover and spinner. This allows a safe internal transition between nacelle cover and spinner. Furthermore, the interface cover prevents an entry of water and dust to the nacelle and the spinner.
A further aspect of the invention is to provide a wind turbine having said nacelle.
The wind turbine comprises a nacelle, which has a nacelle cover, which have a nacelle cover interface, and a spinner covering a hub, wherein the hub has a rotor lock disk, and a spinner opening for entering the inside of the spinner from the nacelle arranged beside the nacelle cover interface, wherein the spinner opening is sized such a way to form a maximum opening for a sideway entry between the rotor lock disk and the spinner.
II should be understood, that the term service personnel generally covers any persons who have to work within the space, independent of whether they are carrying out service work, maintenance, repair, installation, etc.
The terms 3 o'clock, 6 o'clock, 9 o'clock and 12 o'clock position refers to a front view of the rotor. Front view means a view directly towards the rotor tip, which is in alignment with the rotor axis.
BRIEF DESCRIPTION OF DRAWINGS
The invention will now be explained in more detail with respect to exemplary embodiments with reference to the enclosed drawings, wherein:

Figure 1 shows a diagrammatic view of a wind turbine;
Figure 2 shows a cut-out view of the nacelle and rotor of a wind turbine according to Figure 1;
Figure 3 shows a cut-out view of the nacelle cover and the rotor of a wind turbine according to Figure 1;
Figure 4 shows a cut-out view of the nacelle cover and the rotor of a wind turbine according to Figure 3, wherein a rotor blade is in a 6 o'clock position;
Figure 5 shows a cut-out view of the nacelle cover and the rotor of a wind turbine according to Figure 3, wherein a rotor blade is in a 3 o'clock position; and
Figure 6 shows a cut-out view of the nacelle cover and the rotor of a wind turbine according to Figure 3, wherein a rotor blade is in a 12 o'clock position.
The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures.
DETAILES DESCRIPTION OF THE INVENTION
Figure 1 depicts a schematic view of a wind turbine (1) with a tower (2) and a nacelle (3). The nacelle (3) is rotatably mounted on the tower (2). The nacelle (3) incorporates a number of components of a drive train chain (4), a rotor shaft (not shown), for example. Said rotor shaft is connected to a rotor (5). The rotor (5) comprises three rotor blades (6) which are mounted to a hub (7). The hub (7) is connected to the rotor shaft of the drive train chain (4). The rotor blades (6) are adjustably mounted on the hub (7). This is realized by means of pitch drives (8), said pitch drives (8) being part of a pitch system (not shown). The pitch system

controls the rotor speed to given set points. By means of pitch-drives (8), the rotor blades (6) may be moved about a rotor blade (6) axes into different pitch positions, said rotor blade (6) axis extending in an axial direction of the rotor blades (6). Each rotor blade (6) is connected to the hub (7) via its pitch-drive (8). The nacelle (3) is covered by a nacelle cover (9), which has a nacelle cover interface (10). The hub (7) is covered by a spinner (11). The nacelle cover interface (10) provides a passage from the nacelle (3) to the spinner (11).
Figure 2 shows a cut-out view of the nacelle (3) and the rotor (5) of the wind turbine (1) (see Figure 1). One of the three rotor blades (6) (see Figure 1) is in a 6 o'clock position.
The spinner (11) has exactly one spinner opening (12) for entering the inside of the spinner (11) from the nacelle (3) arranged beside the nacelle cover interface (10). As can been seen, the spinner opening (12) is sized in such a way to form a maximum opening for a sideway entry between a rotor lock disk (13) and the spinner (11). The rotor lock disk (13) is part of the hub (7). The spinner opening (12) is so big that a service personnel (14) can enter the spinner (11), when the service personnel (14) laterally passes the rotor lock disk (13). Therefore, the spinner opening (12) has a circular shape. The diameter of the spinner opening (12) is less than 4300 mm. This sideway entry allows the service personnel (14) to enter the spinner (11) in a more comfortable position and to carry his tools for service and maintenance workings. The service personnel (14) is not forced to crawl in the spinner (11) or to climb over an obstacle to enter the spinner (11), as is necessary in the prior art. Furthermore, it is not necessary to enter the spinner (11) from the outside of the rotor (5). Thus, the safety of the service personnel (14) is increased.
The spinner opening (12) is arranged in the area of the nacelle cover interface (10), more precisely at the transition from the nacelle (3) to the spinner (11).

Further, as can been seen, there is a gap (15) between the hub (7) and the spinner (11). This gap (15) is big enough that the service personnel (14) could conduct service and maintenance work in the spinner (11) on the one hand and the service personnel (14) could enter the inside of the hub (7) on the other hand. Preferably, the gap (15) is 500 mm.
The hub (7) having at least one hub entry (21) for entering the inside thereof. Preferably, the hub (7) has three hub entries (21). These three hub entries (21) are arranged 120° to each other. More precisely, the three hub entries (21) are arranged like an equilateral triangle, wherein the sides of the equilateral triangle are parallel to the blades (6). This arrangement allows the service personal (14) to enter the inside of the hub (7) in every said position of the blades (6).
It could further be seen that the rotor lock disk (13) comprises in sum nine holes (22) for lock pins (not shown). This allows fixing the hub in maintenance situation. This is well known in the prior art and do not need a further description.
Figure 3 shows a cut-out view of the nacelle cover (9) and the rotor (5). As said for Figure 2, one of the three rotor blades (6) (see Figure 1) is in a 6 o'clock position.
As can better be seen in Figure 3, the spinner (11) comprises at least two flat spinner landing platforms (16). One flat spinner landing platform (16) is for entering the spinner (11), when one of the three rotor blades (6) is in a 6 o'clock position. A second flat spinner landing platform (16) is for entering the spinner (11), when one of the three rotor blades (6) is in a 3 o'clock position. In the shown embodiment, there are only two flat spinner landing platforms (16) for entering the spinner.(11). Optionally, a third flat spinner landing platform can be provided for entering the spinner (11), when one of the three rotor blades (6) is in a 9 o'clock position.

Further, the nacelle cover (9) has, at its underside, a flat nacelle cover landing platform (17) for the service personnel (14) at the nacelle cover interface (10). This is an area where the service personnel (14) can stand and enter the spinner (11), when one of the rotor blades (6) is in a 3, 6, 9 or 12 o'clock position. The flat nacelle cover landing platform (17) extends substantially over the entire width of the nacelle (3). The flat nacelle cover landing platform (17) is an integral part of a nacelle cover front panel (19). The nacelle front cover panel (19) is fixed to the nacelle cover (9) by bolting or moulding. The flat nacelle cover landing platform (17) is approximately 3500 mm in width and 420 mm in depth.
The flat nacelle cover landing platform (17) and one of the at least two flat spinner landing platforms (16) are arranged at the same level. This allows the service personnel (14) to have a firm stand at the nacelle side as at the spinner side, while entering the spinner (11). Thus, the safety for the service personnel (14) is increased further.
For a safe transition from the nacelle cover (9) and the spinner (11), there is arranged an interface cover (20) between the nacelle cover (9) and the spinner (11). The interface cover (20) prevents an entry of water and dust to the nacelle (3) and the spinner (11).
Figure 4 shows a cut-out view of the nacelle cover (9) in the area of the nacelle cover interface (10) and the rotor (5), wherein one of the rotor blades (6) is in a 6 o'clock position. In particular, Figure 4 depicts the entry situation of the service personnel (14), when one of the blades is in 6 o'clock position in more detail. It is pointed out that the shown position of the service personnel (14) for entering the spinner (11) is only one example. There exist many more positions to enter the spinner (11).
The rotor lock disk (13) has at least one cut-out (18), especially two cut-outs (18), especially three cut-outs (18), for a larger entry space. In the shown embodiment,

the rotor lock disk (13) has three cut-outs (18), and the cut-outs (18) are arranged 120° to each other. In the shown embodiment, the cut-outs (18) have a semi¬circular shape, but it may be appreciated that other shapes are possible as well. The cut-outs (18) maximize the size of the spinner opening (12). Especially this allows an ease of the transition of tools and / or parts of the rotor (5) or rather of parts of the rotor blades (6) as well as parts of the hub (7).
As shown in Figure 2, the service personnel (14) could enter the spinner very easily. There is enough space between the rotor lock disk (13), the hub (7) and the spinner opening (12). If the service personnel (14) want to enter the spinner (11), when his back is directed towards the spinner (11), he has to bend his knees. In this position, his knees have enough space because of the cut-outs (18) of the rotor lock disk (13). Herein, the cut-outs (18) of the rotor lock disk (13) prevent the service personnel (14) from injuries.
A further preferred embodiment is illustrated in Figure 5 which shows a cut-out view of the nacelle cover (9) in the area of the nacelle cover interface (10) and the rotor (5), wherein one of the rotor blades (6) is in a 3 o'clock position. Figure 5 depicts the entry situation of the service personnel (14), when one of the blades is in 3 o'clock position in more detail. It is pointed out that the shown position of the service personnel (14) for entering the spinner (11) is only one example. It may be appreciated that there may exist many more positions to enter the spinner (11).
As can be seen, the service personnel (14) could enter the spinner (11) in the same way when one of the rotor blades (6) is in a 6 o'clock position. As soon as the service personnel (14) have entered the spinner (11), he could enter the inside of the hub (7) and from there to the rotor blade (6), which is in the 3 o'clock position. If the rotor blade (6) is in a 3 o'clock or in a 9 o'clock position, maintenance work could be conduct much easier than in other positons like in 6 o' clock or 12 o'clock position. Thus, the present invention allows the service

personnel (14) to conduct the maintenance work in a more comfortable and in a faster way.
It is clear that the service personnel (14) could enter the spinner (11) in the same way, when one of the blades (6) is in a 9 o'clock position as well as when one of the blades is in 3 o'clock position. The only difference is that the service personnel (14) have to enter the spinner (11) on the opposite side. As already mentioned in the 9 o'clock position there exist no flat spinner landing platform. Nevertheless, the service personnel (14) could enter the spinner (11) without a flat spinner landing platform. However, to make the entry more comfortable, a further flat spinner landing platform, especially a third spinner landing platform, could be arranged in a 9 o'clock position.
A further preferred embodiment is illustrated in Figure 6 which shows a cut-out view of the nacelle cover (9) in the area of the nacelle cover interface (10) and the rotor (5), wherein one of the rotor blades (6) is in a 12 o'clock position. Figure 6 depicts the entry situation of the service personnel (14), when one of the blades is in 12 o'clock position in more detail. It is pointed out that the shown position of the service personnel (14) for entering the spinner (11) is only one example, and there may exist many more positions to enter the spinner (11).
As can be seen, the service personnel (14) could enter the spinner (11) in the same way when one of the rotor blades (6) is in a 6 o'clock or in a 3 o'clock position. As soon as the service personnel (14) have entered the spinner (11), he could enter the inside of the hub (7) and from there to the rotor blade (6), which is in the 12 o'clock position. Thus, the present invention allows the service personnel (14) to conduct the maintenance work in a more comfortable and in a faster way.
In the shown embodiment, in the 12 o'clock position there exists no flat spinner landing platform. Nevertheless, the service personnel (14) could enter the spinner without a flat spinner landing platform in the same way as in the 9 o'clock

position. However, to make the entry more comfortable a further flat spinner landing platform, especially a fourth flat spinner landing platform, could be arranged in a 12 o'clock position.
Summing up, the Figures 4 to 6 show a way how the service personnel (14) could enter the spinner (11) from the nacelle (3) in a more comfortable way, when one of the blades (6) is in 3 o'clock, 6 o'clock, 9 o'clock or 12 o'clock position. In any case, the spinner opening (12) is sized in such a way that the service personnel (14) have enough space for a sideway entry between the rotor lock disk (13) and the spinner (11). After the service personnel (14) has entered the spinner (11), the service personnel (14) is located in the gap (15), and from there the service personnel (14) can enter the hub (7) through the hub entries (22).

CLAIMS
We claim:
1. A nacelle (3) for a wind turbine (1) comprising:
a nacelle cover (9), which has a nacelle cover interface (10), a spinner (10) covering a hub (7), wherein the hub (7) have a rotor lock disk (13), and
a spinner opening (12) for entering the inside of the spinner (11) from the nacelle (3) arranged beside the nacelle cover interface (10), wherein the spinner opening (12) is sized such a way to form a maximum opening for a sideway entry between the rotor lock disk (13) and the spinner (11).
2. The nacelle (3) according to claim 2, characterized by having exactly one spinner opening (12).
3. The nacelle (3) according to claim 1 or 2, characterized in that the spinner opening (12) has a diameter of less than 4300 mm.
4. The nacelle (3) according to one of the preceding claims, characterized in that the nacelle cover (9) has a flat nacelle cover landing platform (17) at the nacelle cover interface (10).
5. The nacelle (3) according to one of the preceding claims, characterized in that the spinner (11) has at least two flat spinner landing platforms (15).
6. The nacelle (3) according to one of the preceding claims, characterized in that the rotor lock disk (13) has at least one cut-out (18), especially two cut-outs (18), especially three cut-outs (18), for a larger entry space.

7. The nacelle (3) according to claim 6, characterized in that the rotor lock disk (13) has three cut-outs (18), which are arranged 120° to each other.
8. The nacelle (3) according to one of the preceding claims, characterized by an interface cover (20) between nacelle cover (9) and spinner (11) for a safe internal transition between nacelle (3) and spinner (11).
9. A wind turbine (1) having a nacelle (3) according to one of the claims 1 to 8.