Wind turbine

Abstract

The invention proposes a wind turbine (100) with a rotor bearing (1), wherein the discharge chambers (7) on both sides of the rotor bearing (1) are connected to one another via a plurality of passages (5) through an outer ring (2) of the rotor bearing (1), the passages being distributed over the circumference of the outer ring (2), and the axis (A) of the rotor bearing (1) is arranged at an angle of 2° to 10° to the horizontal (H) in order to promote the flow of leakage oil through the passages (5).

Description

TECHNICAL FIELD

[0001] The present invention is based on a wind turbine comprising a rotor bearing. BACKGROUND

[0002] A wind turbine generally comprises a rotor bearing which on the one hand transmits forces and torques of the rotor of the wind turbine via the nacelle into the tower and the foundation of the wind turbine and on the other hand is able to transmit torques into the generator of the wind turbine. The rotor bearing generally has an inner ring and an outer ring which are rotatable relative to each other. One of the inner ring and the outer ring is fixedly connected to the nacelle and the other ring is connected to the blades of the wind turbine and to the generator of the wind turbine. The inner ring and the outer ring are arranged coaxially and are connected to each other such that they can be rotated relative to each other about an axis of rotation which extends in the axial direction.

[0003] In order to enable a long-term reliable operation of the wind turbine, it is necessary to lubricate and cool the bearing elements arranged between the inner ring and the outer ring which enable the rotation of the outer ring.

[0004] One method to ensure lubrication and cooling is to introduce oil into the bearing interior space between the outer ring and the inner ring which is generally sealed with sealing means. Despite the sealing means, it is unavoidable that leaks occur. The machine oil which leaks through the leaks has to be recovered. This is generally done using an active pump, but if the pump fails, it can lead to an unnecessary oil loss of the wind turbine. In particular, since the leaking oil has to be pumped through the hub to the nacelle side, it becomes complex to recover the leaking oil from the rotor side in a rotor bearing with a rotating outer ring which is fixed to the rotor. SUMMARY

[0005] It is an object of the present invention to provide a wind turbine which is not affected by the disadvantages of the prior art described above, but which reduces the risk of oil loss and simplifies the recovery of leaking oil from the rotor side of the rotor bearing.

[0006] This is solved by a wind turbine having a tower, a nacelle fixed to the tower, a rotor rotatably mounted on the nacelle via a rotor bearing, the rotor bearing comprising an inner ring, an outer ring, wherein the outer ring is connected to the rotor and the inner ring is connected to the nacelle, wherein the inner ring and the outer ring together define an inner bearing space, and sealing means for sealing the inner bearing space on the nacelle side and on the rotor side of the rotor bearing, wherein the sealing means each comprise at least two seals between which a drain chamber for collecting leaking oil is formed, wherein the drain chambers on both sides of the rotor bearing are connected to each other via a plurality of passages through the outer ring, the plurality of passages being distributed over the circumference of the outer ring, and wherein the axis of the rotor bearing is arranged at an angle of 2° to 10° to the horizontal to promote the flow of leaking oil through the passages to the nacelle side of the rotor bearing.

[0007] The wind turbine according to the present invention provides the possibility to safely return leaked oil to an oil reservoir without an active pump. The leaked oil is collected in a drain chamber and guided through a channel to the nacelle side of the rotor bearing, where the oil reservoir can be provided. The inclined position of the rotor bearing supports the oil flow through the channel. The axis of the rotor bearing in the sense of the present invention is the rotational axis of the rotor bearing.

[0008] Preferred embodiments and further refinements of the present invention can be deduced from the description with reference to the drawings.

[0009] According to a preferred embodiment of the present invention, the channel extends substantially in the axial direction of the rotor bearing. Due to the channel extending substantially in the axial direction, the length of the channel through which the oil needs to pass is shortened. Furthermore, the inclination of the rotor bearing also inclines the channel when extending in the axial direction. The axial direction in the sense of the present invention is arranged parallel to the rotational axis of the rotor bearing.

[0010] According to another preferred embodiment of the present invention, the nacelle side of the rotor bearing is located at one axial end of the rotor bearing and the rotor side is located at the opposite axial end of the rotor bearing. That is, the channel is arranged such that the leaked oil is transported through the rotor bearing in the axial direction. Preferably, the wind turbine comprises an oil reservoir located at the nacelle side of the rotor bearing.

[0011] According to another preferred embodiment of the present invention, the inner ring is equipped with an oil collecting ring having an outlet, wherein the oil collecting ring at least partially surrounds the outer ring to collect the oil flowing out of the channel end in the rotating outer ring. Preferably, the oil collecting ring is arranged at the nacelle side of the rotor bearing. Thus, oil losses at the nacelle side of the rotor bearing can be avoided when the outer ring is moving. Preferably, the oil collecting ring comprises a further sealing. Preferably, the further sealing seals an oil collecting chamber formed between the oil collecting ring and the outer ring. Preferably, the channel opens into the oil collecting chamber. The oil collecting chamber is preferably connected with the oil reservoir.

[0012] According to another preferred embodiment of the present invention, the inner ring and the outer ring are in contact with each other via a sliding surface arranged in the inner bearing space. Thus, the rotor bearing can be a hydrodynamic bearing.

[0013] According to another preferred embodiment of the present invention, at least one raceway is formed on each of the inner ring and the outer ring, and at least one row of rolling elements is arranged in the inner bearing space which are able to roll on the raceways. Thus, the rotor bearing can be a rolling bearing.

[0014] Preferably, the rotor bearing is a hybrid bearing, i.e. the inner ring and the outer ring are in contact with each other via a sliding surface arranged in the inner bearing space, and at least one raceway is formed on each of the inner ring and the outer ring, and at least one row of rolling elements is arranged in the inner bearing space which are able to roll on the raceways.

[0015] According to another preferred embodiment of the present application, the inner bearing space contains oil for lubrication. Preferably, the wind turbine comprises a cooling system for cooling the oil. Preferably, the wind turbine comprises a pump for establishing an oil pressure in the inner bearing space. Preferably, the wind turbine comprises another pump for transporting leaked oil back to the inner bearing space.

[0016] According to another preferred embodiment of the present application, the rotor bearing is a tapered roller bearing or a triple row roller bearing. This type of bearing is very well suited for use in wind turbines. The bearing arrangement ensures that both axial and radial forces are well absorbed. BRIEF DESCRIPTION OF DRAWINGS

[0017] Further details, features and advantages of the present application can be found in the drawings and in the following description of preferred embodiments based on the drawings. The drawings show only exemplary embodiments of the present application and do not limit the basic spirit of the present application.

[0018] Figure 1 Fig. 1 shows a schematic view of a rotor bearing of a wind turbine according to an exemplary embodiment of the present application.

[0019] Figure 2 Fig. 2 shows a schematic view of a rotor bearing of a wind turbine according to another exemplary embodiment of the present application.

[0020] Figure 3 Fig. 3 shows a wind turbine according to an exemplary embodiment of the present application.

[0021] LIST OF REFERENCE SIGNS

[0022] 1 rotor bearing

[0023] 1.1 nacelle side

[0024] 1.2 rotor side

[0025] 2 outer ring

[0026] 3 inner ring

[0027] 4 sealing means

[0028] 4.1 further sealing

[0029] 5 passage

[0030] 6.1 rolling element

[0031] 6.2 sliding surface

[0032] 7 discharge chamber

[0033] 8 outlet

[0034] 9 collecting ring

[0035] 10 Oil collecting chamber

[0036] 100 wind turbines

[0037] Axial / rotation axis

[0038] H horizontal line Detailed Implementation

[0039] In the accompanying drawings, the same parts always have the same reference numerals and are therefore usually mentioned only once.

[0040] Figure 1 A wind turbine according to an exemplary embodiment of the present invention is shown (see Figure 3 A schematic diagram of the rotor bearing 1. Here, the rotor bearing 1 is a rolling bearing with two rows of rolling elements 6.1. The rolling elements 6.1 allow rotational movement about the rotational axis A (also axial A) of the rotor bearing 1 between the inner ring 3 and the outer ring 2 of the rotor bearing 1.

[0041] To ensure the long service life and safe operation of the rotor bearing 1, the internal bearing space contains oil. The oil is pumped into the internal bearing space under pressure to lubricate and cool the rolling elements 6.1, the outer ring 2, and the inner ring 3. For this purpose, the internal bearing space is sealed axially along A by a sealing device 4 at the rotor side 1.2 and at the nacelle side 1.1 opposite to the rotor side 1.2.

[0042] Despite the sealing device 4, oil leakage is still possible. Sealed discharge chambers 7 are arranged at the rotor side 1.2 and nacelle side 1.1 of the rotor bearing 1, via the sealing device 4. Oil leaking from the internal bearing space is collected in the discharge chambers 7. To drain the oil from the discharge chambers 7, a channel 5 is arranged circumferentially around the outer ring 2 in the axial direction A, connecting the discharge chambers 7 on the rotor side 1.2 and the nacelle side 1.1. The diameter of the channel 5 is preferably at least 10 mm. The channels 5 may be evenly or unevenly distributed on the circumference of the outer ring 2.

[0043] The rotation axis A of rotor bearing 1 is inclined at 2° to 10° relative to the horizontal line H. Therefore, gravity support oil flows through channel 5 from the discharge chamber 7 on the rotor side 1.2 to the discharge chamber 7 on the nacelle side 1.1.

[0044] To collect oil flowing through passage 5 on the nacelle side 1.1 even when the outer ring 2 rotates, the inner ring 3 has an oil collecting ring 9. The oil collecting ring 9 partially surrounds the outer ring 2 to collect oil flowing out from passage 5. Another seal 4.1, together with the oil collecting ring 9 and the outer ring 2, forms an oil collecting chamber 10. In the figure shown here, the oil collecting chamber 10 is also the discharge chamber 7 on the nacelle side 1.1.

[0045] Oil can flow from oil collection chamber 10 into the oil reservoir on the cabin side 1.1 through outlet 8.

[0046] Figure 2 A schematic view of a rotor bearing 1 of a wind turbine 100 according to another exemplary embodiment of the present application is shown. The wind turbine 100 is similar to the wind turbine 100 shown in Figure 3 Figure 1 Unlike the preferred embodiment shown, the rotor bearing 1 here is a hybrid bearing. The rotor bearing 1 comprises rolling elements 6.1 and sliding surfaces 6.2. It is also conceivable that the rotor bearing 1 is designed as a plain bearing without rolling elements 6.1 and comprising only sliding surfaces 6.2.

[0047] Figure 3 A wind turbine 100 according to an exemplary embodiment of the present application is shown.​

Claims

1. A wind turbine (100) comprising a tower, a nacelle fixed to the tower, and a rotor rotatably mounted on the nacelle via a rotor bearing (1), the rotor bearing (1) comprising: Inner ring (3); Outer ring (2), The outer ring (2) is connected to the rotor, and the inner ring (3) is connected to the nacelle. The inner ring (3) and the outer ring (2) together define the internal bearing space; and Multiple sealing devices (4) are used to seal the internal bearing space on the nacelle side (1.1) and rotor side (1.2) of the rotor bearing (1). Each of the plurality of sealing devices (4) includes at least two seals, and a discharge chamber (7) for collecting leaked oil is formed between the at least two seals. The characteristic feature is that the discharge chambers (7) on both sides of the rotor bearing (1) are interconnected via a plurality of channels (5) passing through the outer ring (2), the plurality of channels (5) being distributed on the circumference of the outer ring (2), and the axis (A) of the rotor bearing (1) being arranged at an angle of 2° to 10° to the horizontal line (H) to facilitate the leakage oil flowing through the channels (5) to the nacelle side (1.1) of the rotor bearing (1), and The inner ring (3) is equipped with an oil collecting ring (9) having an outlet (8), wherein the oil collecting ring (9) at least partially surrounds the outer ring (2) to collect oil flowing out from the end of the channel (5) in the rotating outer ring (2).

2. The wind turbine (100) according to claim 1, characterized in that, The channel (5) extends substantially along the axis (A) of the rotor bearing (1).

3. The wind turbine (100) according to any one of claims 1 or 2, characterized in that, The nacelle side (1.1) of the rotor bearing (1) is located at one shaft end of the rotor bearing (1), and the rotor side (1.2) is located at the opposite shaft end of the rotor bearing (1).

4. The wind turbine (100) according to claim 1, characterized in that, The inner ring (3) and the outer ring (2) are in contact with each other via a sliding surface (6.2) arranged in the inner bearing space.

5. The wind turbine (100) according to claim 1, characterized in that, At least one raceway is formed on each of the inner ring and the outer ring, and at least one row of rolling elements (6.1) capable of rolling on the raceway are arranged in the internal bearing space.

6. The wind turbine (100) according to claim 1, characterized in that, The internal bearing space contains oil for lubrication.

7. The wind turbine (100) according to claim 1, characterized in that, The rotor bearing (1) is a tapered roller bearing or a three-row roller bearing.

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