A fan includes an annular frame, a rail assembly, a driving member and blades. The blades are connected to the driving member. The driving member is electromagnetically movable along the maglev assembly that extends along an edge of the annular frame. The driving member does not contact the annular frame or the maglev assembly so that when the fan is used, the maglev assembly is energized to generate an electromagnetic force between the maglev assembly and the driving member to move the driving member along the edge of the annular frame to drive the blades to rotate. Therefore, the blades can be rotated without having to use any motor behind the annular frame, thereby reducing the volume of the fan.

A ventilation device has a holder, in particular a ventilation frame, with a substantially circular continuous opening for receiving a ventilation wheel rotating about the central axis, thereof. The opening is bordered by an edge face running substantially cylinder-symmetrically about the central axis. As the edge face in two separate, diametrically opposed peripheral sections the radius is at least partly enlarged in comparison to the cylinder-symmetrical form in the remaining peripheral sections, and/or a circular projection of she edge face, which projection projects radially inwards, is axially offset away from a space provided for the ventilation wheel. Because of she corresponding shaping of the edge face of the opening, contact and/or development of noise between the ventilation wheel and the edge of the opening is prevented in the ventilation frame in the event of a yawing of the ventilation wheel.

An air circulator includes a blower unit that is provided with an airflow opening on a front side of the blower unit. A grill is provided in the airflow opening, and is provided with airflow guide blades in a spiral manner Each of the airflow guide blades is convex toward an airflow direction between its inner end portion and its outer end portion to form the grill three-dimensionally. The grill further includes a circular ring that intersects with the airflow guide blades.

Disclosed embodiments relate to a combination axial fan and LED lighting system configured to fit into the footprint of a standard ceiling tile. Disclosed embodiments further include ceiling tiles with a built-in fan and/or LED lighting. The disclosed systems may include a housing container and an axial fan. The fan has a fan cavity including air diversion mechanism to direct air from the fan cavity toward the lighting and fan components. The inventions include an airflow surface to direct air existing the fan cavity along an LED light fixture. Moreover, disclosed embodiments include one or more UV light sources which irradiate contaminants as air flows through the ceiling tile.

The present invention provides a multi-stage compressor for a gas turbine engine. The compressor has: a first outer casing, a second outer casing radially outward of the first outer casing, and a first bleed plenum one or more second bleed plenums located between the first and second outer casings and arranged to receive, in use, bleed flows of compressed air from respective stages of the compressor and to send the bleed flows to respective ports in the second outer casing. The first bleed plenum overlaps the, or each, second bleed plenum such that the, or each, second bleed plenum fluidly communicates with its port via a respective duct which, on extending between an off-take from the second bleed plenum to the port, passes through the first bleed plenum. The, or each, duct is configured to accommodate relative movement between the first and second outer casings.

A refrigerated merchandiser includes a case having a lower wall, an upper wall, a rear wall, and a rear panel. A product support area is at least partially defined by the lower wall, the upper wall, and the rear panel. A first air passageway is formed in the case for supplying refrigerated air to the product support area. A fan is positioned in the first air passageway for creating airflow. An evaporator coil is disposed in the air passageway to condition the airflow. A duct is coupled to the rear panel to create a second air passageway.

A ducted fan assembly has a central axis, a duct having an outer wall and an inner wall, a fan hub at least partially disposed on the central axis, a plurality of fan blades coupled to the fan hub, and a first stator. The first stator has a first end coupled to the inner wall, a second end coupled to the inner wall, and a hub interface disposed between the first end and the second end, wherein the hub interface is coupled to the fan hub.

In various implementations, a fan system may include a housing and a fan. The fan may reside in an orifice of the housing. The fan system may include a grate disposed proximate a top surface and an ice deflector. The ice deflector may inhibit ice formation on portions of the housing, orifice, and/or fan residing in the orifice.

Apparatus and methods are described including manufacturing an impeller by forming a structure having first and second bushings at proximal and distal ends that are connected to one another by at least one elongate element. The elongate element is made to radially expand and form a helical elongate element. An elastomeric material is coupled to the helical elongate element, such that the helical elongate element with the elastomeric material coupled thereto defines a blade of the impeller. The coupling is performed such that a layer of the material disposed around a radially outer edge of the helical elongate element forms the effective edge of the impeller blade. A step is performed to enhance bonding of the elastomeric material to the helical elongate element in a manner that does not cause a protrusion from the effective edge of the impeller blade. Other applications are also described.

Apparatus and methods are described including coupling a rigid tube to a drive cable that comprises a plurality of coiled wires, by placing ends of the drive cable and the rigid tube at a given location within a butt-welding overtube. The ends of the drive cable and the rigid tube are visible when they are disposed at the given location within the butt-welding overtube, via a window defined by the butt-welding overtube. The placement of the drive cable within the butt-welding overtube is such that a helical groove within a portion of the butt-welding overtube is disposed over the drive cable. Welding rings are formed around the butt-welding overtube. Other applications are also described.