A main bearing assembly of a wind turbine includes at least one main bearing with a rotation axis and at least one bearing row in which a rotor shaft of the wind turbine is mounted. The main bearing assembly has at least one stationary bearing ring, a circulating bearing ring and rolling elements. A method of extending the service life or servicing the main bearing assembly includes rotating the stationary bearing ring about the rotation axis of the main bearing assembly. Alternatively, only a new stationary bearing ring, preferably with at least two bearing ring segments is installed instead of a damaged outer ring, in particular without further important bearing components such as the inner ring being exchanged.

A main bearing assembly of a wind turbine includes at least one main bearing with a rotation axis and at least one bearing row in which a rotor shaft of the wind turbine is mounted. The main bearing assembly has at least one stationary bearing ring, a circulating bearing ring and rolling elements. A method of extending the service life or servicing the main bearing assembly includes rotating the stationary bearing ring about the rotation axis of the main bearing assembly. Alternatively, only a new stationary bearing ring, preferably with at least two bearing ring segments is installed instead of a damaged outer ring, in particular without further important bearing components such as the inner ring being exchanged.

A hover-capable aircraft is described that comprises a drive unit, a rotor and a transmission interposed between the drive unit and the rotor; the transmission comprises a gear; the gear, in turn, comprises a main body rotatable about a first axis and a plurality of first teeth projecting in a cantilever fashion from the main body; the gear comprises a first pair of first rings axially opposite to each other and cooperating with the gear so as to exert a radial force on the gear.

A hover-capable aircraft is described that comprises a drive unit, a rotor and a transmission interposed between the drive unit and the rotor; the transmission comprises a gear; the gear, in turn, comprises a main body rotatable about a first axis and a plurality of first teeth projecting in a cantilever fashion from the main body; the gear comprises a first pair of first rings axially opposite to each other and cooperating with the gear so as to exert a radial force on the gear.

A sleeve of a steering column includes (i) an outer tube and an inner tube that are movable relative to each other, and (ii) an adjustment system. The adjustment system includes a screw for adjusting the axial position along an adjustment axis constrained to move in translation with a first of the two elements by at least two guide bearings for rotationally guiding the adjusting screw about the adjustment axis. At least one of the bearings supporting the adjusting screw is a guide bearing with axial force take-up for blocking the translational movement of the adjusting screw.

A wheel bearing assembly with an outer race, a first roller bearing, a second roller bearing, a first shield, and a second shield. The outer race may have a first inner surface and a second inner surface. The first roller bearing and the second roller bearing may have a plurality of rollers configured to engage with the first inner surface and with the second inner surface, respectively. The first shield and the second shield may be configured to engage with the first roller bearing and the second roller bearing, respectively, and push the first roller bearing and the second roller bearing against the first inner surface and the second inner surface, respectively. The first shield and the second shield may each have a rubber seal configured to reduce passage of fluid into or out of the first roller bearing and the second roller bearing, respectively.

There is provided a grease composition for improving the chemical stability of the grease composition and increasing the fatigue life of a member in which the grease composition is used. The problems can be solved by a grease composition including a poly-α-olefin; a urea-based thickener; molybdenum dithiophosphate; and barium sulfonate, wherein a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less.

There is provided a grease composition for improving the chemical stability of the grease composition and increasing the fatigue life of a member in which the grease composition is used. The problems can be solved by a grease composition including a poly-α-olefin; a urea-based thickener; molybdenum dithiophosphate; and barium sulfonate, wherein a difference between an SP value of the urea-based thickener and an SP value of the poly-α-olefin is 3.5 or less.

A wing (5) for an aircraft (1) including a main wing (11) and a high lift assembly (13) having a high lift body (15), and a connection assembly (17) movably connecting the high lift body (15) to the main wing (11), wherein the connection assembly (17) includes a first connection element (19) and a second connection element (21) movably mounted to the main wing (11) and mounted to the high lift body (15), wherein the connection assembly (17) includes a first drive unit (27) drivingly coupled to the first connection element (19), a second drive unit (29) drivingly coupled to the second connection element (21) and a third connection element (57) movably mounted to the main wing (11) and mounted to the high lift body (15), the third connection element (57) is arranged between the first connection element (19) and the second connection element (21).

A wing (5) for an aircraft (1) including a main wing (11) and a high lift assembly (13) having a high lift body (15), and a connection assembly (17) movably connecting the high lift body (15) to the main wing (11), wherein the connection assembly (17) includes a first connection element (19) and a second connection element (21) movably mounted to the main wing (11) and mounted to the high lift body (15), wherein the connection assembly (17) includes a first drive unit (27) drivingly coupled to the first connection element (19), a second drive unit (29) drivingly coupled to the second connection element (21) and a third connection element (57) movably mounted to the main wing (11) and mounted to the high lift body (15), the third connection element (57) is arranged between the first connection element (19) and the second connection element (21).