An impeller for a viscous flow fan includes a hub having a longitudinal axis, and a plurality of ring-shaped wave blades disposed about and coupled to a perimeter of the hub, the wave blades disposed in a parallel and spaced apart from one another along the longitudinal axis by a blade gap. Each wave blade includes a center coincident with the longitudinal axis, an inner perimeter, an outer perimeter, and a wave-like cross-section about the perimeter of the hub in a direction perpendicular to the longitudinal axis, wherein at least a portion of the inner perimeter of at least one of the wave blades is spaced from the perimeter of the hub to form an air intake gap.

An impeller includes a main plate, an annular side plate and blades. The blades each have: an inner circumferential end; an outer circumferential end; a sirocco blade portion formed as a forward-swept blade portion, and having an outlet angle that is greater than 90 degrees; and a turbo blade portion formed as a swept-back blade portion and including the inner circumferential end. The blades include a first blade portion and a second blade portion that are provided on respective sides of the main plate. The impeller including a region in which a first inter-blade distance is greater than a second inter-blade distance, where an inlet-blade distance is a distance between any adjacent two of the blades in the circumferential direction, the first inter-blade distance is the inter-blade distance of the first blade portion, and the second inter-blade distance is the inter-blade distance of the second blade portion.

An electric submersible pump (ESP) with reduced vibration is provided. In an implementation, an ESP section has radial bearings placed at shaft locations of reduced vibration to reduce wear. The locations of reduced vibration are selected to avoid areas of high vibration and vibrational waves that reinforce each other due to structure resonance and natural excitation frequencies. In an implementation, a radial bearing is positioned at a node of reduced vibration of a standing vibrational wave. In an implementation, a succession of multiple radial bearings are spaced at different intervals from each other to avoid conventional even spacing of the bearings that causes standing waves, resonance waves, and vibrational waves at natural excitation frequencies. In an implementation, a span between adjacent radial bearings is selected to spare other adjacent bearings at different spans the effects of vibrations that may extend over a range of excitation frequencies in the ESP section.

The present application discloses a blade, comprising a blade tip, a blade root, a leading edge, and a trailing edge, wherein the leading edge and the trailing edge each extend from the blade tip to the blade root; the blade may rotate around a rotation axis, and the rotation axis and a normal plane of the rotation axis perpendicularly intersect at the foot of the perpendicular; a projection of the leading edge on the normal plane along the rotation axis is a first curve, and the first curve has an even number of inflection points. The blade of the present application can reduce noise and improve aerodynamic performance when the blade rotates.

A heat dissipation fan includes a fan blade assembly. The fan blade assembly includes a plurality of fan blades and a plurality of silencers connected to the plurality of fan blades and evenly arranged along a rotation direction of the plurality of fan blades. A center of gravity of the plurality of silencers coincides with a rotation center of the heat dissipation fan. At least some fan blades of the plurality of fan blades have different contact surfaces with air.

A double curvature blade for a portion of system. The system may include a pump, such as a submersible pump. The pump may include a multiple or single stage pump. The pump may be powered by a selected motor.

A return channel for a centrifugal turbo machine. The return channel includes a plurality of return channel vanes, arranged around a return channel axis. Each return channel vane includes: a leading edge at a first distance from the return channel axis, a trailing edge at a second distance from the return channel axis, the second distance being smaller than the first distance. A respective flow passage is defined between each pair of adjacently arranged return channel vanes. The return channel vanes are arranged with a non-constant pitch around the return channel axis.

A diagonal fan is disclosed and includes a frame and an impeller. The frame includes an inlet, an outlet, an accommodation space and a guiding wall. The inlet and the outlet are communicated through the accommodation space. The guiding wall is extended along an axial direction to the accommodation space. The impeller is accommodated within the accommodation space and includes a conical section shell. When the impeller is rotated, an airflow flowing is generated. The outer diameter of the hub of the impeller is expended gradually in a direction from the inlet toward the outlet, so that the flowing direction of the airflow is expended gradually around the peripheral of the impeller. A gap having a spacing distance is substantially maintained to form a backflow channel. A backflow is transported through an intake section, a horizontal section and an exhaust section of the backflow channel, and converged with the airflow.

A fan structure including a center portion, multiple fan blades, and a fixing ring is provided. The center portion includes a bottom surface and a center shaft. The center shaft is perpendicular to the bottom surface, and the direction in which the center shaft extends is an axial direction. The fan blades are mutually separated and connected to the bottom surface of the center portion and are disposed around the axial direction. Each of the fan blades has a height which is parallel to the axial direction. The fixing ring simultaneously contacts the side of the fan blades which is away from the center shaft. Along the axial direction, with the bottom surface of the center portion as a reference surface, the fixing ring is disposed at a range of 40% to 80% of the height of each of the fan blades.