A tidal current generating unit, including a turbine, a hub, a generator, a bearing set and a fixed flange. The turbine is connected to the rotor of the generator through the hub, and the rotor is rotatably mounted on the outer circumference of the stator of the generator via the bearing set, and the turbine drives the rotating component to rotate to generate electricity. A density of a blade is much smaller than a density of the seawater, such that the blade has a sufficient buoyancy that offsets the gravity of the rotating component in seawater, and the load of the bearing sets is reduced. The blade is a backswept blade and the hydrodynamic central axis of the blade is inclined from a flange central axis of the blade at a first angle, and the blade is able to automatically change the pitch without relying on an external force.

A sealed bearing module for a tidal turbine that has a rotor having rotor blades disposed on a rotor hub and a rotor shaft carrying the rotor for transmitting a drive torque from the rotor hub to a transmission or a generator in a nacelle which nacelle has a housing. The bearing module includes a first bearing ring and a second bearing ring, the first bearing ring is a split bearing ring having a first bearing ring part and a second bearing ring part, the second bearing ring has at least one axially extending bore for attaching the second bearing ring directly to the nacelle housing, the first bearing ring is configured to be connected to the rotor shaft and/or to the rotor hub, and the split bearing ring is preloaded by a preload element.

A sealed bearing module for a tidal turbine that has a rotor having rotor blades disposed on a rotor hub and a rotor shaft carrying the rotor for transmitting a drive torque from the rotor hub to a transmission or a generator in a nacelle which nacelle has a housing. The bearing module includes a first bearing ring and a second bearing ring, the first bearing ring is a split bearing ring having a first bearing ring part and a second bearing ring part, the second bearing ring has at least one axially extending bore for attaching the second bearing ring directly to the nacelle housing, the first bearing ring is configured to be connected to the rotor shaft and/or to the rotor hub, and the split bearing ring is preloaded by a preload element.

A tidal current generating unit, including a turbine, a hub, a generator, a bearing set and a fixed flange. The turbine is connected to the rotor of the generator through the hub, and the rotor is rotatably mounted on the outer circumference of the stator of the generator via the bearing set, and the turbine drives the rotating component to rotate to generate electricity. A density of a blade is much smaller than a density of the seawater, such that the blade has a sufficient buoyancy that offsets the gravity of the rotating component in seawater, and the load of the bearing sets is reduced. The blade is a backswept blade and the hydrodynamic central axis of the blade is inclined from a flange central axis of the blade at a first angle, and the blade is able to automatically change the pitch without relying on an external force.

A guide bearing system including a pad adjuster to traverse at least one bearing in a direction to adjust a radial clearance. The system can further include a sensor for measuring deviations in the radial clearance. In some embodiments, the guide bearing system includes a controller that receives a distance signal from the sensor measuring the radial clearance and signals the pad adjuster to traverse the at least one bearing to compensate for the deviations in the radial clearance.

A guide bearing system including a pad adjuster to traverse at least one bearing in a direction to adjust a radial clearance. The system can further include a sensor for measuring deviations in the radial clearance. In some embodiments, the guide bearing system includes a controller that receives a distance signal from the sensor measuring the radial clearance and signals the pad adjuster to traverse the at least one bearing to compensate for the deviations in the radial clearance.

A wave-power system configured to produce electric power is provided. The wave-power system may comprise a floating body structure, a set of blades attached to the floating body structure, a weight assembly, a bidirectional to unidirectional shaft assembly and/or a power unit. The weight assembly may comprise a plurality of weights which may rotate around a first axis of rotation as a result of floating movements of the floating body structure. Rotation of the plurality of weights may cause an input shaft of the bidirectional to unidirectional shaft assembly to rotate. An output shaft of the bidirectional to unidirectional shaft assembly may rotate in a first direction, regardless of a direction of rotation of the input shaft. Rotation of the output shaft causes the power unit to produce the electric power.

A wave-power system configured to produce electric power is provided. The wave-power system may comprise a floating body structure, a set of blades attached to the floating body structure, a weight assembly, a bidirectional to unidirectional shaft assembly and/or a power unit. The weight assembly may comprise a plurality of weights which may rotate around a first axis of rotation as a result of floating movements of the floating body structure. Rotation of the plurality of weights may cause an input shaft of the bidirectional to unidirectional shaft assembly to rotate. An output shaft of the bidirectional to unidirectional shaft assembly may rotate in a first direction, regardless of a direction of rotation of the input shaft. Rotation of the output shaft causes the power unit to produce the electric power.

A rotor shaft unit for a tidal system, which tidal system includes a main frame and a rotor and a housing connected to the rotor, includes a rotor shaft configured to be connected to the main frame, at least one bearing unit for rotatably supporting the housing for rotation relative to the rotor shaft, and a sleeve configured to be mounted in the main frame, the sleeve being disposed around a first end portion of the rotor shaft and connected to the rotor shaft by a friction connection. Also a tidal system including the rotor shaft unit.

A rotor shaft unit for a tidal system, which tidal system includes a main frame and a rotor and a housing connected to the rotor, includes a rotor shaft configured to be connected to the main frame, at least one bearing unit for rotatably supporting the housing for rotation relative to the rotor shaft, and a sleeve configured to be mounted in the main frame, the sleeve being disposed around a first end portion of the rotor shaft and connected to the rotor shaft by a friction connection. Also a tidal system including the rotor shaft unit.