A vacuum pump system includes an air-cooled, O-ring sealed vacuum pump and an oil management system with an LED illuminated clear tank for observation of the oil condition as well as a large oil inlet and outlet for rapid and safe oil changes while the pump is operating. The oil management system is also configured to prevent oil from the sump from being drawn into an evacuated AC/R system when the pump is stopped and the intake ports are not sealed from the high vacuum AC/R system. The oil management system includes a preferential vacuum relief system that allows air instead of the oil from the sump to be drawn back into the evacuated lines.

Leading edge protectors for a wind turbine blade are disclosed. The leading edge protectors are configured to at least partially cover a blade leading edge section. The leading edge protectors comprise a main body having a substantially constant thickness and having a trailing end. The leading edge protectors further comprise a plurality of irregularities arranged on an outer surface of the main body upstream from the trailing end and configured to energize a boundary layer. Wind turbines comprising such leading edge protectors are also disclosed.

Methods of operating a variable speed wind turbine as a function of wind speed are described. The wind turbine has a rotor with a plurality of blades and a generator. The generator has a design rotor speed which varies so as to follow a theoretical generator rotor rotational speed curve describing the rotational speed of the rotor as a function of wind speed. The method comprises determining an erosion risk condition of the blades, determining erosion damage of one or more of the blades accumulated over time and changing the rotor rotational speed from the design rotor speed as a function of the determined erosion risk condition and the determined accumulated erosion damage. Wind turbines configured to carry out such methods are also described.

A wind turbine comprising a pod and an aerodynamic rotor having a rotor head or a spinner. The rotor head or spinner is arranged in that case in the afflux flow direction of the wind in front of the rotor blade plane. Provided in or at the rotor head or the spinner of the rotor is a mist eliminator which rotates with the rotor head or spinner. The mist eliminator has an end which is in the form of an opening in the rotor head or the spinner. Air can enter through that end and flow through the mist eliminator in such a way that substantially water droplet-free air is present at the outlet of the mist eliminator, and can be used for cooling the generator.

A protective cover for a leading-edge of a wind turbine rotor blade is provided. The protective cover is pre-formed into a curved shape to accommodate at least a part of a leading-edge section including the leading-edge of the wind turbine rotor blade to be protected. The protective cover includes a pressure side section, a suction side section and a centerline in-between the pressure side section and the suction side section. The centerline runs in longitudinal direction of the protective cover. Thickness of the protective cover in a cross section of the protective cover in transverse direction has a thickness distribution corresponding to a standardized normal distribution.

Provided is a method for corrosion protection in bolt holes of a wind turbine, whereby a sleeve made of a corrosion resistant metallic material is inserted into the bolt hole, in particular covering the whole length of the bolt hole wall, and at least partly expanded using an expander tool to be fixed in the bolt hole.

A wave energy converter utilizes a flotation module that rises and falls with the passage of waves, a submerged tube containing a constriction which multiplies the speed of the water passing therethrough, a turbine (or other hydrokinetic apparatus) positioned so as to extract energy from the accelerated flow of water within and/or through the tube, and a submerged gas- or liquid-filled chamber housing one or more energy conversion components (e.g. generators, transformers, rectifiers, inverters). By providing a chamber in proximity to the turbine, generators can be placed in closer proximity to the turbine that turns them, and the shared shaft can be shorter than if the generators were placed in the buoy adjacent to the surface.

A leading edge of a wind-turbine blade has a carefully designed predetermined shape. After operation of the blade, erosion damages that shape and the blade needs repair. Repair is difficult to carry out in the field or, for offshore turbines, at sea. A shroud (8) for repairing a damaged leading edge of a wind-turbine blade (2) is rigid and has a shape matching the predetermined shape of the leading edge. Advantageously the shroud has a multi-layered structure in which a base layer (10) of the shroud comprises a rigid material.

Methods and apparatus for a modular hydrokinetic turbine. An apparatus includes modular vertically floating units tethered to shore with a generator residing above water and vertically oriented blades submerged in water to convert a latent kinetic energy of a moving waterway into electricity.

A scroll compressor may include a casing configured to receive a rotation shaft and a driving unit; a compression unit provided with a frame configured to rotatably support the rotation shaft, a first scroll fixed to the casing, and a second scroll configured to be connected to the rotation shaft and engaged with the first scroll. An oldham ring is provided with a plurality of key portions to guide the second scroll to perform an orbiting movement, wherein at least one of the frame, the first scroll, and the second scroll includes a respective key groove formed to receive a respective key portion; and a respective wear-resistant member mounted to cover an inner surface of the respective key groove in contact with the respective key portion.