Sealed bearing module

Abstract

A sealed bearing module for a tidal turbine, the tidal turbine including a hub and at least one rotor blade, the sealed bearing module including an inner ring, and an outer ring, and a seal system configured to seal the bearing module. The outer ring includes axially extending bores configured to receive fasteners for attaching the outer ring directly to the hub, and the inner ring includes axially extending bores for attaching the inner ring directly or indirectly to the rotor blade.

Claims

1. A sealed bearing module for a tidal turbine, the tidal turbine including a hub and at least one rotor blade, the sealed bearing module comprising: a hub side configured to face and be connected to the hub; a rotor blade side axially opposite the hub side; an outer ring; an inner ring; a spacer ring axially adjacent the inner ring; and a seal system configured to seal the bearing module, wherein the outer ring includes blind axial bores extending into the outer ring from the hub side, the axial bores being configured to receive an attachment means for attaching the outer ring directly to the hub, and the inner ring includes axial through bores for attaching the inner ring to the spacer ring, the spacer ring includes blind axial bores having openings facing the hub side, the blind axial bores of the spacer ring being aligned with the axial through bores of the inner ring and configured to receive a threaded fastener for securing the spacer ring to the inner ring, and the spacer ring includes blind axial bores on the rotor blade side for attaching the spacer ring to the rotor blade.

2. The sealed bearing module according to claim 1, wherein the outer ring is a split outer ring.

3. The sealed bearing module according to claim 1, wherein the seal system is detachably disposed directly on the outer ring and inner ring.

4. The sealed bearing module according to claim 1, wherein the seal system includes a slip surface that radially surrounds the inner ring or the spacer ring.

5. The sealed bearing module according to claim 4, wherein the seal system includes a plurality of seal units, and wherein each seal unit includes a seal element disposed in a respective seal carrier ring, each seal element having a seal lip in contact with the slip surface.

6. The sealed bearing module according to claim 5, wherein one of the seal units is disposed directly on the outer ring, wherein the seal system includes a seal cover, and wherein the remaining seal units are disposed between the seal unit on the outer ring and the seal cover.

7. The sealed bearing module according to claim 6, wherein the seal units are exchangeable from the side of the seal cover.

8. The sealed bearing module according to claim 4, wherein the seal system comprises a first seal unit including a first seal element disposed in a first seal carrier ring and a second seal unit including a second seal element disposed in a second seal carrier ring and a third seal unit including a third seal element disposed in a third seal carrier ring, each of the first, second and third seal elements having a seal lip in contact with the slip surface.

9. The sealed bearing unit according to claim 8, wherein the first seal unit is located axially between the second seal unit and the outer ring and wherein the first seal carrier ring is mounted directly on the outer ring and the second seal carrier ring is mounted directly on the first seal carrier ring.

10. The sealed bearing unit according to claim 9, including a fourth seal element mounted directly on the outer ring and having a seal lip in contact with the slip surface, the fourth seal element being located axially between the first seal carrier ring and the outer ring.

11. The sealed bearing module according to claim 10, wherein the spacer ring has a radially outer surface, wherein a slip ring is mounted on the radially outer surface of the spacer ring, and wherein the slip surface is formed on a radially outer surface of the slip ring.

12. The sealed bearing module according to claim 1, wherein the inner ring includes gear teeth.

13. The sealed bearing module according to claim 1, wherein the outer ring is a split outer ring, wherein the inner ring is attachable to the rotor blade indirectly via the spacer ring, wherein the seal system includes a slip surface that radially surrounds the inner ring or the spacer ring and a plurality of seal units, each seal unit including a seal element disposed in a respective seal carrier ring, each seal element having a seal lip in contact with the slip surface, wherein one of the seal units is disposed directly on the outer ring, wherein the seal system includes a seal cover, wherein the remaining seal units are disposed between the seal unit on the outer ring and the seal cover, and wherein the inner ring includes gear teeth.

14. The sealed bearing module according to claim 1, wherein the seal system includes a slip surface that radially surrounds the inner ring or the spacer ring and a plurality of annular seal elements each having at least one seal lip in sliding contact with the slip surface.

15. A tidal turbine including a hub and at least one rotor blade, between which a sealed bearing module according to claim 1 is disposed.

16. A sealed bearing module for a tidal turbine, the tidal turbine including a hub and at least one rotor blade, the sealed bearing module comprising: a hub side configured to face and be connected to the hub; a rotor blade side axially opposite the hub side; an outer ring; an inner ring; a spacer ring axially adjacent the inner ring, the spacer ring having a radially outer surface; a slip ring having a radially inner surface mounted on the radially outer surface of the spacer ring and a radially outer surface forming a slip surface; and a seal system configured to seal the bearing module, the seal system including a first seal unit comprising a first seal element disposed in a first seal carrier ring, the first seal carrier ring being mounted to the rotor blade side of the outer ring with the first seal element in contact with the slip surface, wherein the outer ring includes blind axial bores extending into the outer ring from the hub side, the axial bores being configured to receive a threaded fastener for attaching the outer ring directly to the hub, the inner ring includes first axial bores for attaching the inner ring to the spacer ring, the spacer ring includes second axial bores on the rotor blade side for attaching the spacer ring to the rotor blade, and wherein the first axial bores do not communicate with the second axial bores.

17. The sealed bearing module according to claim 16, including a second seal unit comprising a second seal element disposed in a second seal carrier ring, the second seal carrier ring being mounted to the rotor blade side of the first seal carrier ring with the second seal element in contact with the slip surface.

18. The sealed bearing unit according to claim 17, including a third seal element mounted directly on the outer ring and having a seal lip in contact with the slip surface, the third seal element being located axially between the first seal carrier ring and the outer ring.

19. The sealed bearing unit according to claim 18, wherein the first and second axial bores are blind bores.

20. The sealed bearing unit according to claim 16, wherein the first and second axial bores are blind bores.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1 is a sectional view of a sealed bearing module for a tidal turbine according to an embodiment of the present disclosure.

DETAILED DESCRIPTION

(2) In the following, identical or functionally equivalent elements are designated by the same reference numbers.

(3) FIG. 1 shows a sealed bearing module 1. The bearing module 1 is disposed between a hub 2 and a rotor blade (not shown) of a tidal turbine in order to rotatably support the rotor blade with respect to the hub 2. The bearing module 1 can be disposed in a housing (not shown). If the rotor blade is moved by the seawater, in particular due to the tides, a generator can be driven via the hub 2 in order to generate current. The rotor blade can be adjusted in its angle of attack (pitch adjustment) via gear teeth 40.

(4) The bearing module 1 includes an inner ring 4 and an outer ring 6. In the embodiment shown it is a triple row roller bearing, for which reason the outer ring 6 is split in two. The two parts of the outer ring 6 are connected to each other by an attachment means 8 such as screws or bolts. Rolling elements 20 are disposed between the inner ring 4 and the outer ring 6.

(5) The bearing module 1 includes bores 12 in the outer ring 6 and bores 14 in the inner ring 4 in order to directly connect the bearing module 1 to the hub 2 or the rotor blade. Here the outer ring 6 is directly attached to the hub by an attachment means 16, for example, a screw or bolt.

(6) In the embodiment shown the inner ring 4 is not directly attached to the rotor blade, but rather is attached via a spacer ring 22. Here the spacer ring 22 is connected to the inner ring 4 via an attachment means 18 which may comprise a screw or a bolt. From the rotor blade side the spacer ring 22 is then connected to the rotor blade by an attachment means 30, for example, another screw or bolt. Here the inner ring assembly is thus configured two-part and is comprised of the spacer ring 22, which includes bores facing toward the rotor blade side and toward the inner ring, and the inner ring 4, which includes through-bores for attaching the spacer ring. Alternatively the inner ring 4 can be longer in the axial direction and can be directly connected to the rotor blade. Here the attaching of the inner ring 4 to the rotor blade is also effected from the rotor blade side.

(7) Since the attaching by the bores 12 in the outer ring 6 can be effected from the hub side and not from the side of the outer ring 6, the bearing module 1 can already be completely assembled before installation. In particular a seal system 10 can already be installed.

(8) In addition, the inner ring 4 is directly provided with gear teeth 40. A simple connection to the gear teeth of a drive can be effected by these gear teeth 40. Due to the connection between rotor blade, inner ring 4 (via the spacer ring 22 and the gear teeth 40) the position of the rotor blade with respect to the hub can be adjusted in order to be able to react to flow speeds, flow strength, or flow direction and to be able to set an optimum angle of attack.

(9) In order to seal the bearing module 1, the bearing module 1 includes the seal system 10. The seal system 10 includes a plurality of seal units. Each of the seal units includes a seal carrier ring 26, 34, 32 and a seal element disposed therein including a seal lip 38. One of the seal units is directly connected to the outer ring 6 by its seal carrier ring 26. For this purpose an attachment means 24, for example, a screw, is screwed-in by the seal carrier ring 26 into the outer ring 6 from the side of the seal unit. This seal unit thus serves for attaching the seal system 10 to the outer ring. For this purpose the corresponding seal carrier 26 is adapted in its axial dimensions to the axial dimensions of the outer ring 6. In this way, the entire seal system 10 can be easily removed as needed from the outer ring 6 and exchanged.

(10) A further seal unit serves for sealing outward. The seal carrier ring 34 of this seal unit represents a type of seal cover. A plurality of seal units including their seal carrier rings 32 are disposed between this and the seal unit 26. Each of these seal carrier rings 32 includes a seal element including a seal lip 38. The seal carrier rings 32 are connected to each other via attachment means 36, such as screws or bolts. Here two seal carrier rings 26, 32, 38 are always connected to each other. Here the attachment means 36 are circumferentially offset from one another in the axial direction.

(11) In operation the seal lips 38 slip against a slip surface 28. Here a sealing of the slip surface 28 with respect to the spacer ring 22 is effected via O-rings 44.

(12) If one of the seal lips 38 is worn out, it can be exchanged in a simple manner. For this purpose the seal cover 34 is first removed. Then the subsequent seal unit including its seal carrier ring 32 and the seal lip 38 can be removed and exchanged as a unit.

(13) The first four seal lips 38-1 to 38-4 serve as a series connection for keeping seawater out of the bearing. Here the first seal lip 38-1 must withstand the highest pressure and is therefore worn out first. If the first seal lip 38-1 no longer withstands the pressure of the seawater, the second seal lip 38-2 following the first assumes this function. Here the first seal lip 38-1 also acts as a filter for larger impurities. A third and a fourth seal lip 38-3, 38-4 are provided as further spare seal lips. In the seal system 10 a sensor (not shown), for example a moisture sensor or pressure sensor, can be disposed that can issue a signal when seawater reaches the third or fourth seal lip 38-3, 38-4. As soon as such a signal is issued, an exchange of the seal lips 38 can be initiated. The fifth seal lip 38-5, which is disposed closest to the outer ring 6, serves to hold lubricant in the bearing.

(14) For further protection of the sealed bearing module 1 a sacrificial anode 42 can be disposed on the slip surface 28. The sacrificial anode 42, which is an electrode made of a piece of base metal, serves to protect the bearing module 1 against contact corrosion. Here the material of the sacrificial anode 42 itself is destroyed by oxidation, while corrosion of the components of the bearing module 1 is delayed or completely avoided.

(15) In summary a compact bearing assembly is provided by the disclosed sealed bearing module. This can already undergo required tests, such as, for example, for seal-tightness, prior to installation at its destination. Expensive tests after installation are therefore no longer required.

REFERENCE NUMBER LIST

(16) 1 Bearing module 2 Hub 4 Inner ring 6 Outer ring 8 Attachment means 10 Seal system 12 Bore 14 Bore 16 Attachment means 18 Attachment means 20 Rolling element 22 Spacer ring 24 Attachment means 26 Seal carrier ring 28 Slip surface 30 Attachment means 32 Seal carrier rings 34 Seal cover 36 Attachment means 38 Seal lips 40 Gear teeth 42 Sacrificial anode 44 O-rings