A fan assembly is provided. The fan assembly includes a fan, a fan casing circumscribing the fan, and a fan casing heating system in thermal communication with the fan casing. The fan includes a hub, and a plurality of fan blades extending from the hub. Each fan blade of the plurality of fan blades terminates at a respective blade tip. A clearance gap is defined between the fan casing and the blade tips. The fan casing heating system is configured to apply heat to the fan casing when the fan is operating in a first operational mode, and remove the applied heat when the fan transitions into a second operational mode.

An axial compressor comprises a plurality of compressor stages positioned axially adjacent each other within a casing. Each of the plurality of compressor stages includes a rotor segment and a banded stator segment. An annulus is formed between the casing and an outer flowpath ring of the banded stator segment. A pathway may be provided that establishes an air flowpath between the annulus and another annulus formed by an adjacent stage.

An axial compressor comprises a plurality of compressor stages positioned axially adjacent one another within a casing. Each of the plurality of compressor stages comprise a rotor segment and a banded stator segment positioned axially adjacent the rotor segment. An annulus is formed between the casing and an outer flowpath ring of the stator segment. A vane of each stator segment comprises a member extending into the annulus.

An axial compressor comprises a plurality of compressor stages positioned axially adjacent within a casing. Each of the plurality of compressor stages comprise a rotor segment and a banded stator segment positioned axially adjacent the rotor segment. An annulus is formed between the casing and an outer flowpath ring of the stator segment. A pathway is provided that establishes an air flowpath between an entry pathway in a first stage and an exit pathway in a second stage.

A fan has an external rotor motor with a motor section and an electronics section. The motor section and the electronics section are arranged axially adjacent to each other along the axis of rotation. The fan, when operated as intended, generates, via the fan wheel, a pressure difference between its suction side, which is preferably associated with the rotor, and its pressure side, which is preferably associated with the motor electronics. A continuous cooling duct runs within the external rotor motor from a pressure-side inflow opening, at least along sections of the rotor, to a suction-side outflow opening. An exclusively passive cooling air flow through the cooling duct can be generated in operation by the pressure difference generated by the fan wheel.

A ventilation fan includes a shaft, a rotor, a motor housing, a bearing housing, and an air bearing. The shaft has a shaft body that extends between a first shaft end and a second shaft end. The shaft body defines a first port and a bore. The rotor is disposed about the shaft. The motor housing is disposed about the shaft and is axially spaced apart from the rotor. The bearing housing is disposed about the shaft. The air bearing is disposed proximate the second shaft end and is disposed between the bearing arm and the second shaft end.

Actuator devices useable to change orientation of one or more vanes, including an actuator rod and an actuator device body configured to allow the actuator rod to move along the axis inside the actuator device body, and having an inlet flange configured to allow a third fluid to enter a space between the actuator device body and the actuator rod, and an outlet flange configured to allow the third fluid to exit the actuator device body. Besides providing a fluid seal between the first fluid and the second fluid, the third fluid may also heat the actuator rod thereby preventing ice formation.

A combination cooling and heating fan structure includes an electronic device for controlling a driving device to drive a fan blade assembly to rotate within a first rotational speed range and thereby cause cold convection when the driving device is started alone. The electronic device includes a limiting module for limiting the driving device to rotate within a second rotational speed range, which is smaller than the first rotational speed range, when the driving device and a heating device are started at the same time. That is, when the driving device and the heating device are started simultaneously, the limiting module limits the driving device to rotate within the second rotational speed range for the fan blade assembly to blow hot air through an indoor environment and cause heat convection, which increases the temperature of the indoor environment while preventing quick loss of thermal energy during the heat convection.

A centrifugal fan includes a main plate, a blade connected to the main plate, and a shroud having an annular shape and connected to a shroud-side end of the blade that is an end opposite a main-plate-side end of the blade connected to the main plate. The centrifugal fan rotates about a rotation axis to suction a fluid through an opening of the shroud and discharge the fluid through the blade in a radial direction. A leading edge of the blade includes a recess located next to a point at which a shroud inner surface of the shroud that faces the main plate is connected to the leading edge and curving inwardly from the point toward a trailing edge and a projection located closer to the main plate than is the recess and projecting in the rotation direction.

The present document describes a centrifugal ceiling fan. The fan comprises a casing, a motor and a centrifugal propeller. The casing comprises an upper surface comprising an air inlet and a lower surface comprising an air outlet. In an embodiment, the lower surface has a round bowl-like shape including a plurality of openings defining the air outlet. The propeller comprises a shaft and a plurality of blades provided around the shaft. The blades may be curved to push the air in all directions between a first direction substantially perpendicular to the rotation shaft and a second direction substantially parallel to the rotation shaft in order to evenly ventilate the room. The fan may include a heating element for heating the air as it exits from the fan.