An intermediate shaft includes a first hollow shaft portion in which a plurality of grooves are formed in a longitudinal direction thereof, a second hollow shaft portion coupled at one end thereof to a first slip member, provided to be accommodated inside the first hollow shaft portion, and slipped into the first hollow shaft portion when a collision occurs, and a shaft portion to which a second slip member is coupled, provided to be accommodated inside the second hollow shaft portion, and slipped into the second hollow shaft portion when the collision occurs. A first press-in portion is formed on an inner circumference of the first hollow shaft portion to protrude therefrom, thereby pressing and supporting the first slip member.

A sliding member includes an overlay layer made of a resin on a side of a sliding surface of a bearing alloy layer. When a valley void volume Vvv (μm.sup.3/μm.sup.2) in the sliding surface of the overlay layer is defined as Vv1, Vv1 is in a range of 0.015≤Vv1≤0.200.

A vertical radial guide bearing of fixed circular bore construction surrounds a journal attached firmly to a rotating shaft, is lubricated via pot lubrication means, has a bearing bore surface that is shaped to include viscosity oil pumps that are situated below the surface of the oil in the pot, are adjacent the bottom of the bearing, have associated supply ports remote from the journal, and have associated discharge grooves that extend vertically up the bearing bore surface to a circumferential groove adjacent the top of the bearing, wherein the viscosity oil pumps are sized to pump oil quickly up the grooves so as to develop an oil film between the journal and bearing surfaces, this film generated by normal hydro-dynamic action having sufficient pressure and thickness to rapidly separate the journal and bearing surfaces and to keep them separated.

A turbine generator comprises an elongate member, a support structure, a turbine wheel and an electrical generator. The support structure comprises a shaft and supports the elongate member for rotation about a rotation axis. The turbine wheel attached to the elongate member. The electrical generator comprises a rotor and a stator, the rotor being attached to the elongate member and the stator being arranged around the elongate member. The elongate member is provided with a bore and the shaft extends through an end of the elongate member into the bore so as to support it for rotation about the rotation axis.

A sliding member includes an overlay layer made of a resin on a side of a sliding surface of a bearing alloy layer. When a valley void volume Vvv (μm.sup.3/μm.sup.2) in the sliding surface of the overlay layer is defined as Vv1, Vv1 is in a range of 0.015≤Vv1≤0.200.

A system for slew ring repair includes a drive mechanism and a tool coupled thereto. The tool may include a fixture structurally configured to secure the tool to a frame on a top end of a wind tower, and a rotatable shaft having a proximal end and a distal end, where the proximal end is coupled to the drive mechanism and the distal end is structurally configured to insert within a housing on the top end of the wind tower that contains a slew ring of a wind turbine disposed on the wind tower. The tool may further include a grinder disposed on the distal end of the rotatable shaft, where the grinder is structurally configured to engage the slew ring while being rotated by the drive mechanism for repair or maintenance of the slew ring.

A turbine generator comprises an elongate member, a support structure, a turbine wheel and an electrical generator. The support structure comprises a shaft and support the elongate member for rotation about a rotation axis. The turbine wheel is attached to the elongate member. The electrical generator comprises a rotor and a stator, the rotor being attached to the elongate member and the stator being arranged around the elongate member. The elongate member is provided with a bore and the shaft extends through an end of the elongate member into the bore so as to support it for rotation about the rotation axis.

A magnetic bearing may include an inner ring and an outer ring arranged concentrically. The inner ring and the outer ring may be mounted rotatably relative to each other by way of axial and radial magnets. The magnetic bearing may also include a back-up bearing, which is integrated into at least one of the outer ring or the inner ring both in an axial direction and in a radial direction. The outer ring may be multipiece and may include a recess that opens inwards and receives the inner ring. Further, the back-up bearing may be made of aluminum, austenitic steel, bronze, or ceramic, and the back-up bearing may operate as a shielding device that shields magnetic fields emitted by the axial and radial magnets from one another.

A system for slew ring repair includes a drive mechanism and a tool coupled thereto. The tool may include a fixture structurally configured to secure the tool to a frame on a top end of a wind tower, and a rotatable shaft having a proximal end and a distal end, where the proximal end is coupled to the drive mechanism and the distal end is structurally configured to insert within a housing on the top end of the wind tower that contains a slew ring of a wind turbine disposed on the wind tower. The tool may further include a grinder disposed on the distal end of the rotatable shaft, where the grinder is structurally configured to engage the slew ring while being rotated by the drive mechanism for repair or maintenance of the slew ring.

A bearing, including: an axis of rotation; an outer ring; an inner ring located radially inward of the outer ring; a cage including at least one protrusion extending in a radial direction; a ball disposed in the cage; and at least one recess. The outer ring includes a recess included in the at least one recess and a protrusion included in the at least one protrusion is located in the recess. The inner ring includes a recess included in the at least one recess and a protrusion included in the at least one protrusion is located in the recess.