An impeller for a centrifugal turbomachine includes: a hub having a small-diameter portion positioned at a first end portion in an axial direction and a large-diameter portion positioned at a second end portion in the axial direction, the large-diameter portion having a greater diameter than the small-diameter portion; and a blade having a first edge positioned at an axial-directional position of the small-diameter portion and a second edge positioned at an axial-directional position of the large-diameter portion, the blade being disposed on an outer peripheral surface of the hub. The impeller is configured such that, when a first radial-directional cross section is a cross section of the impeller at an axial-directional position passing a tip of the first edge, at least a part of the first radial-directional cross section in a blade-height range of 50% or more is inclined downstream in a rotational direction of the impeller with respect to a radial direction.

A blade (112) includes an upper surface and a lower surface, the upper surface being a pressure face (212), and the lower surface being a suction face (214), a blade tip (216) and a blade base (218), a leading edge (222) and a trailing edge (220), where the pressure face (212) and the suction face (214) each extend from the blade tip (216) to the blade base (218), and each extend from the leading edge (222) to the trailing edge (220). The blade (112) further includes a bent part (262), the bent part (262) being arched from the pressure face (212) toward the suction face (214), where the bent part (262) has a lowest point in a radial cross section of the blade (112), and a connecting line (252) of the lowest points extends in a direction from the leading edge (222) to the trailing edge (220).

Blades (20a to 20c) of a propeller fan (10) have different circumferential pitches φ1, φ2, and φ3. The blades (20a to 20c) have different masses so that the center of gravity of the propeller fan (10) is positioned on a rotational center axis (11) of the propeller fan (10). Blade body portions (42c) of the blades (20a to 20c) have different thicknesses. In contrast, camber lines of the blades (20a to 20c) in blade cross section have the same shape, projections of the blades (20a to 20c) on a plane perpendicular to the rotational center axis (11) of the propeller fan (10) have the same shape, and leading edge portions (41a to 41c) of the blades (20a to 20c) have the same shape. As a result, a propeller fan (10) having reduced noise and vibrations can be achieved.

Disclosed is a fan. The fan includes a support; a first motor installed on the support, the first motor having a first rotation shaft; a first blade installed on the first rotation shaft; a second motor installed on the support, the second motor having a second rotation shaft and being coaxial with the first motor; a second blade installed on the second rotation shaft, a tilt direction of the second blade being opposite to a tilt direction of the first blade; and an electric control board electrically connected to the first motor and the second motor and configured to control a relative rotation of the first motor and the second motor.

Disclosed is a fan. The fan includes a support; a first motor installed on the support, the first motor having a first rotation shaft; a first blade installed on the first rotation shaft; a second motor installed on the support, the second motor having a second rotation shaft and being coaxial with the first motor; a second blade installed on the second rotation shaft, a tilt direction of the second blade being opposite to a tilt direction of the first blade; and an electric control board electrically connected to the first motor and the second motor and configured to control a relative rotation of the first motor and the second motor.

A ceiling fan may include a shaft coupled to a ceiling, a cover to surround the shaft, a main blade having a blade hole which is a space open inward, and a sub-blade positioned in the blade hole. The sub-blade is disposed to have an angle of attack different from an angle of attack of the main blade. The ceiling fan may resolve a red zone of the air flow and may improve air volume and the flow rate due to the dual blades.

The present disclosure relates to a pump.

The pump of the present disclosure includes: a housing; an impeller disposed in the housing and rotating to generate a flow of fluid; and a pump motor configured to rotate the impeller, wherein the impeller includes: a first plate having a disk shape; a boss extending vertically from a center of the first plate, and coupled to a rotating shaft of the pump motor; a plurality of blades extending from an outer circumferential surface of the boss in a radial direction of the first plate; and a second plate having a surface parallel to the first plate, spaced apart from the first plate by a predetermined distance, and connected to the plurality of blades.

A method for forming a blade for a gas turbine engine may include forming a suction side sheath and a pressure side sheath, a first cavity and a second cavity established on opposed sides of a rib, forming a structural core configured for positioning in an interior section of the blade between the suction side sheath and the pressure side sheath, the structural core including a first core member, a second core member and a root interconnecting the first and second core members, assembling the suction side sheath and the pressure side sheath with the structural core such that the first core member is positioned in the first cavity and such that the second core member is positioned in the second cavity, and securing the suction side sheath to the pressure side sheath to form the blade.

A fan includes a support, a motor mounted at the support and including a first rotation shaft, a first blade mounted at one end of the first rotation shaft, a transmission mechanism mounted at the support and connected to another end of the first rotation shaft, and a second blade. The transmission mechanism includes a second rotation shaft. A rotation direction of the second rotation shaft is opposite to a rotation direction of the first rotation shaft. The second blade is mounted at the second rotation shaft. A tilt direction of the first blade is opposite to a tilt direction of the second blade.

A fan includes a support, a motor mounted at the support and including a first rotation shaft, a first blade mounted at one end of the first rotation shaft, a transmission mechanism mounted at the support and connected to another end of the first rotation shaft, and a second blade. The transmission mechanism includes a second rotation shaft. A rotation direction of the second rotation shaft is opposite to a rotation direction of the first rotation shaft. The second blade is mounted at the second rotation shaft. A tilt direction of the first blade is opposite to a tilt direction of the second blade.