A lubrication system for a pitch bearing of a wind turbine includes a lubricant for lubricating contact surfaces between an outer race, an inner race, and a plurality of rolling elements of the pitch bearing. Further, the lubrication system includes a lubricant inlet formed into a first side of the inner race and an inlet seal for sealing the lubricant inlet so as to prevent the lubricant from leaking from the lubricant inlet. Moreover, the lubrication system includes a lubricant outlet formed into an opposing, second side of the inner race and a lubricant collection container arranged adjacent to and in fluid communication with the lubricant outlet and mounted to the inner race. Thus, during operation of the wind turbine, at least one of a slope of the pitch bearing, gravity, and a centrifugal effect cause the lubricant to flow throughout the pitch bearing to lubricate the contact surfaces without exiting a closed volume defined by the inlet seal(s) and the lubricant collection container(s).

A wind turbine gearbox, in particular planetary gearbox, has at least one gear which is mounted on an axle, wherein a sliding surface is arranged between the gear and the axle. The sliding surface is arranged on at least one layer of a deposition welded material made from a sliding bearing material. Furthermore, a method produces the wind turbine gearbox.

A wind turbine gearbox, in particular planetary gearbox, has at least one gear which is mounted on an axle, wherein a sliding surface is arranged between the gear and the axle. The sliding surface is arranged on at least one layer of a deposition welded material made from a sliding bearing material. Furthermore, a method produces the wind turbine gearbox.

A method involves directing lubricant to different consumers which are to be monitored via their lubricant. The lubricant is drained through drain lines connected to the consumers and directed to a tank. At least some the lubricant in the drain lines or the consumers is extracted into extraction lines. Flow from the extraction lines is selectively directed to a measurement device, which then measures a characteristic of the lubricant. A system for carrying out such a method is also provided, wherein the system includes a multiplexer for selectively directing flow from the extraction lines.

A method involves directing lubricant to different consumers which are to be monitored via their lubricant. The lubricant is drained through drain lines connected to the consumers and directed to a tank. At least some the lubricant in the drain lines or the consumers is extracted into extraction lines. Flow from the extraction lines is selectively directed to a measurement device, which then measures a characteristic of the lubricant. A system for carrying out such a method is also provided, wherein the system includes a multiplexer for selectively directing flow from the extraction lines.

A main bearing housing for supporting a main rotor shaft of a wind turbine, wherein the main bearing housing defines a first end, a second end and a floor region intermediate the first and second ends. The main bearing housing comprises a first bearing arrangement positioned at the first end of the main bearing housing, a second bearing arrangement positioned at the second end of the main bearing housing, wherein the floor region includes a first oil sump positioned at the first bearing arrangement, and a second sump positioned at the second bearing arrangement. Advantageously, the embodiments of the invention provide that the bearings of the main bearing housing are lubricated by a lubrication system that includes sumps positioned at each of the fore and aft bearings of the main rotor shaft. The fore and aft bearings are therefore supplied with oil at suitable lubrication points and are part of the lubrication system that supplies oil to other components in the wind turbine that require oil lubrication, for example the gearbox and/or the generator bearings. The fore and aft bearings of the main bearing housing therefore do not require a separate lubrication system, such as a grease-based system and so the overall lubrication requirements for the nacelle are simplified.

A main bearing housing for supporting a main rotor shaft of a wind turbine, wherein the main bearing housing defines a first end, a second end and a floor region intermediate the first and second ends. The main bearing housing comprises a first bearing arrangement positioned at the first end of the main bearing housing, a second bearing arrangement positioned at the second end of the main bearing housing, wherein the floor region includes a first oil sump positioned at the first bearing arrangement, and a second sump positioned at the second bearing arrangement. Advantageously, the embodiments of the invention provide that the bearings of the main bearing housing are lubricated by a lubrication system that includes sumps positioned at each of the fore and aft bearings of the main rotor shaft. The fore and aft bearings are therefore supplied with oil at suitable lubrication points and are part of the lubrication system that supplies oil to other components in the wind turbine that require oil lubrication, for example the gearbox and/or the generator bearings. The fore and aft bearings of the main bearing housing therefore do not require a separate lubrication system, such as a grease-based system and so the overall lubrication requirements for the nacelle are simplified.

An arrangement including a transmission and a generator is disclosed. The generator includes a generator rotor being non-rotatably connected to an output shaft of the transmission or configured to be connectable to the output shaft of the transmission. An assembly bearing that supports the generator rotor in the output shaft is also disclosed.

An arrangement including a transmission and a generator is disclosed. The generator includes a generator rotor being non-rotatably connected to an output shaft of the transmission or configured to be connectable to the output shaft of the transmission. An assembly bearing that supports the generator rotor in the output shaft is also disclosed.

The present disclosure relates to electrical machines (100, 200) configured to be fed by pulse width modulation from a power converter (170) and comprising a stator (110), a rotor (120), a rotor shaft (130) and one or more bearings (140, 141) arranged between the rotor (120) and the stator (110). The electrical machine (100, 200) further comprising an electrical shunt (160, 161) arranged between the rotor shaft (130) and the stator (110). The present disclosure also relates to methods (500) to mitigate electrical discharge machining bearing currents in electrical machines (100, 200).