A main bearing housing for a wind turbine comprising a bearing arrangement having a sump located in a floor region of the main bearing housing. The sump comprises a floor pan surrounded by a side wall and includes an overflow arrangement configured to permit fluid to spill from the sump. The overflow arrangement comprises a spill passage configured with a spill inlet at or near the floor pan of the sump and a spill outlet located in a position between the spill inlet and an upper edge of the sump side wall. An advantage of the invention is that since the spill passage is fed with oil from a position that is close to the bottom of the sump, debris and sediment at the bottom of the sump tends to be entrained with the flow of oil and so tends not to collect at the bottom of the sump. The lubrication system therefore is able to clean the oil more effectively because the debris and sediment is encouraged to circulate around the lubrication system.

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 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 lubrication system for a wind turbine is provided, the lubrication system including a lubricant consumer to which fresh lubricant is supplied and out of which used lubricant is extracted, a pump for pumping fresh lubricant to the lubricant consumer, a waste lubricant collector where used lubricant can flow after being extracted from the lubricant consumer, and a plurality of containers delivering fresh lubricant to the lubrication system.

A lubricant dispenser for filling a lubricant reservoir of a wind turbine is provided. The lubricant dispenser includes a carrier configured to receive a lubricant container, wherein the carrier includes at least a first and second support for supporting a first and second end of the lubricant container and. The lubricant dispenser further includes a flow connection having a first end configured to be coupled to the lubricant container and a second end configured to be coupled to the lubricant reservoir, and a squeeze mechanism that is mechanically coupled to the second support and that is actuatable to move the second support towards the first support such that a lubricant container disposed between the first and second supports is squeezed, whereby the content of the lubricant container is discharged through the flow connection. A wind turbine lubrication system and method of refilling a wind turbine lubricant reservoir are provided.

Provided is a diagnosis technique with high reliability when a state of lubricating oil of a rotary machine such as a wind power generator is diagnosed by a state monitoring sensor. A diagnosis system of lubricating oil includes a lubricating oil utilization device, a lubricating oil tank for storing lubricating oil to be supplied to the lubricating oil utilization device, and a sensor which measures characteristics of the lubricating oil. In this system, the state of the lubricating oil is diagnosed by using sensor data obtained after a time required for air bubbles in the lubricating oil generated at the time of use of the device disappear elapses since the lubricating oil utilization device is regularly or irregularly stopped.

Provided is a bearing arrangement for a wind turbine including a bearing housing and a drive shaft, whereby the drive shaft is arranged within the bearing housing in an axial direction along a longitudinal axis of the bearing housing. The bearing arrangement further includes a downwind bearing and an upwind bearing, whereby the downwind bearing and the upwind bearing are arranged between the bearing housing and the drive shaft. The bearing housing includes a drain outlet arranged in a bottom part of the bearing housing, the bottom part of the bearing housing being located underneath the drive shaft in a direction of gravity, whereby at least one inner side of the bottom part of the bearing housing is arranged so as to form a funnel, whereby the drain outlet is an opening of the formed funnel.

A pump system for supplying lubricant to components of a wind turbine comprises: a pump for pumping lubricant through a fluid circuit of the wind turbine; a drive means for driving the pump; and, a gearbox arrangement arranged to couple the drive means to the pump. The gearbox arrangement comprises a rotatable input shaft configured to be driven by the drive means and a rotatable output shaft configured to drive the pump. The input shaft is rotatable in a first direction of rotation and a second direction of rotation when driven by the drive means. The output shaft is rotatable in the first direction of rotation, and the speed of rotation of the output shaft is determined by an operational mode of the gearbox arrangement. In a first mode of operation, when the input shaft rotates in the first direction of rotation at a first speed of rotation, the gearbox arrangement is configured to drive the output shaft to rotate also in the first direction of rotation at the first speed of rotation. In a second mode of operation, when the input shaft rotates in the second direction of rotation at the first speed of rotation, the gearbox arrangement is configured to drive the output shaft to rotate in the first direction of rotation at a second speed of rotation.

Provided is a grease collection arrangement for collecting waste grease from a grease lubricated rotor blade pitch bearing of a wind turbine, whereby the grease collection arrangement includes at least one waste grease collector and multiple extraction tubes, wherein each one of the multiple extraction tubes is connected to the at least one waste grease collector and the multiple extraction tubes are configured to being connected to multiple grease outlets of the rotor blade pitch bearing, whereby the grease collection arrangement is configured such that the waste grease from the rotor blade pitch bearing can flow into the at least one waste grease collector by gravity and centrifugal forces.