A method for performing uptower maintenance of a wind turbine in order to replace the main bearing on the turbine shaft is disclosed. Embodiments of this method to perform maintenance may include installing a rotor lock to resist rotation of the main shaft during maintenance, providing a lifting device in order to elevate the main shaft, removing the main bearing from its main bearing housing, and installing a replacement split main bearing. A crane may also be installed uptower to assist in the maintenance.

A slewing bearing for vertical structural support, including a first bearing ring, a second bearing ring and at least one row of rolling elements arranged between the first and second bearing rings. The first or second bearing ring is provided with a gear for receiving the drive of an input torque, and the gear is provided axially thereunder with a lubricant collecting member for keeping the lubricant. A rotary support device is provided for supporting in a vertical structure. The device provides a first member that supports substantially in a vertical direction, a second member that is substantially supported by the first member in the vertical direction, and the slewing bearing acting as a rotary support between the first and second members. The first member is fixedly connected to the first bearing ring and the second member is fixedly connected to the second bearing ring.

When the compressed air is not applied, an inclined surface, which is positioned at an upstream side with respect to the supply direction of the compressed air, of the lip part is in contact with the inclined surface of the inner ring. When the compressed air is applied, a contact area between the inclined surface, which is positioned at the upstream side with respect to the supply direction of the compressed air, of the lip part and the inclined surface of the inner ring becomes smaller, as compared to when the compressed air is not applied.

To provide a rolling bearing having a hard film on an inner ring raceway surface and an outer ring raceway surface of the rolling bearing that improves peeling resistance of the hard film, shows the original property of the hard film, and suppresses the attackability to a mating material. A rolling bearing 1 has an inner ring 2 having an inner ring raceway surface 2a on an outer circumference, an outer ring 3 having an outer ring raceway surface 3a on an inner circumference, and rolling elements 4 that roll between the inner ring raceway surface 2a and the outer ring raceway surface 3a. A hard film 8 includes a foundation layer formed directly on the inner ring raceway surface 2a or the outer ring raceway surface 3a and mainly formed of Cr and WC, a mixed layer having a gradient composition formed on the foundation layer and mainly formed of WC and DLC, and a surface layer formed on the mixed layer and mainly formed of DLC. In a roughness curve of a surface on which the foundation layer is formed, the arithmetical mean roughness Ra is 0.3 μm or less and the root mean square gradient RΔq is 0.05 or less.

A method for operating a plain bearing including: determining a first rotational speed at which a transition of a lubrication state takes place, or at which friction in the plain bearing is at a minimum; comparing the first rotational speed to a threshold value; and if the rotational speed has exceeded the threshold value, operating the bearing to produce a self-repairing effect.

A method for increasing load capacity of a surface-hardened rolling bearing raceway of a rolling bearing ring element may involve providing a rolling bearing ring element with an unhardened core region and, at least in certain portions, an outer layer hardened to a surface hardening depth. A rolling bearing raceway may be formed in a region of the hardened outer layer. The method may further involve hard rolling the rolling bearing raceway with a roll. The diameter of the roll is 8 to 25 times the surface hardening depth. A surface pressure prevailing in a rolling contact between the roll and the rolling bearing raceway during the hard rolling is between 2000 MPa and 3300 MPa. The method further involves machining the rolling bearing raceway after the hard rolling.

A seal arrangement is disclosed for sealing an interior space between a bearing housing and a rotatable shaft with respect to a surrounding area. The seal arrangement includes a seal body which can be fastened to the bearing housing with a first end and a second end. The seal body is extended in an elongate manner along a main extent direction and is configured to be arranged in an annular manner around the rotatable shaft in a mounted state. The first end and the second end have a common butt joint. A projecting region is arranged at the first end of the seal body and projects tangentially with respect to the rotatable shaft in the direction of a predefined main rotational direction of the rotatable shaft. The projecting region projects beyond the seal body and overlaps the butt joint.

A wind turbine includes a rotor shaft. The rotor shaft is mounted via a bearing assembly having a first bearing ring and a second bearing ring mounted to rotate in relation to the first bearing ring. A hydrostatically supported first friction bearing segment is disposed on the first bearing ring and interacts with a first friction face that is disposed on the second bearing ring. The first friction bearing segment is received in a receptacle pocket of the first bearing ring such that a first compression chamber is formed between the first bearing ring and the first friction bearing segment. The first friction bearing segment is configured such that a second compression chamber is formed between the first friction bearing segment and the second bearing ring, wherein the first compression chamber and the second compression chamber are connected by a duct that runs through the first friction bearing segment.

In a first aspect, a roller pitch bearing for a wind turbine is provided. The roller pitch bearing comprises a first bearing component and a second bearing component, the first bearing component being configured to rotate with respect to the second bearing component; wherein one of the first and the second bearing components is configured to be coupled to a wind turbine blade and the other one of the first and the second bearing components is configured to be coupled to a rotor hub of a wind turbine. The roller pitch bearing further a limiting structure attached to the first bearing component, the limiting structure radially extending from the first bearing component towards the second bearing component to limit a radial movement between the bearing components. In further aspect, a rotor for a wind turbine comprising a roller pitch bearing is provided.

The present invention describes a wind turbine comprising a hub, at least one blade and at least one pitch bearing to connect the at least one blade to the hub, the at least one pitch bearing comprising at least an inner ring and an outer ring, and at least a rolling race, wherein the wind turbine further comprises at least a tensioning system configured to exert a radial compression force to at least a part of the outer ring of the at least one pitch bearing, thus increasing the resultant stiffness of the at least one pitch bearing.