The present invention provides a device and a system for simulating the buoyancy and the resistive force. The system comprises a pair of wearable devices, each of the wearable devices comprises a calf shell, a first ducted fan, a second ducted fan, a first connection component, a second connection component and a tracker. The first ducted fan and the second ducted fan operate in non-zero duty cycles for generating a first force in a first direction, and a second force in a second direction. The first direction and the second direction are in different directions. The sum of the first force and the second force are the sum of the resistive force, the buoyant force, the potential weights and the weight of the wearable device. The tracker further transmits feedback data to control system.

A blower motor is provided and includes a support assembly provided with a first stop step surface, a stator assembly disposed in the support assembly, a rotor assembly disposed in the stator assembly and an end cover disposed on the stator assembly and abutted against the support assembly and provided with a second stop step surface. The rotor assembly includes a rotating shaft and two ends of the rotating shaft are respectively provided with a first bearing and a second bearing. A resilient gasket is provided on one of the first stop step surface and the second stop step surface. The bearings are positioned by springs and cooperate with the resilient gasket to apply a tightening force to the bearings, which can reduce clearances in the bearings and effectively prevent balls in the bearings from making noise under a high-frequency vibration.

A counter-rotating axial air moving device includes a front rotor and a rear rotor. The front rotor includes a front hub and a plurality of front blades, and the number of the front blades is equal to or greater than 7 and equal to or less than 11. The rear rotor is disposed on the downstream side of the front rotor. The rear rotor includes a rear hub and a plurality of rear blades, and the number of the rear blades is equal to or greater than 6 and equal to or less than 10. The front rotor and the rear rotor are stacked with each other with a total thickness and a diameter. The ratio of the total thickness to the diameter is equal to or more than 0.91 and equal to or less than 1.5.

A suspended system with orientation control. The system may have a frame, a sign attached to the frame, a plurality of sensors, at least two thrusters, and a microcontroller operatively coupled to the plurality of sensors and the thrusters. The frame is configured to be suspended from a support, and the sign is configured to display a graphic. The plurality of sensors is configured to track an orientation of the frame. The thrusters are configured to adjust the orientation of the frame. Each of the thrusters may have an axis oriented in a direction perpendicular to the frame. The microcontroller is configured to receive a selected orientation of the frame, receive the current orientation of the frame from the sensors, compare the orientation of the frame with the selected orientation, and control the thrusters to adjust the orientation of the frame into the selected orientation.

The present disclosure provides a fan including a hub and multiple fan blades coupled to the hub and located circumferentially along the hub. Each fan blade extends between a root and a tip edge thereof and includes a first portion inclined at a first predefined angle with respect to the hub. The first portion induces an axial flow of air. The fan blade also includes a second portion extending from the first portion and between a leading edge and a trailing edge of the fan blade. The second portion is embodied as an airfoil defining an angle of attack to induce a radial inward flow of air. A radius of curvature of a trailing edge segment of the second portion is less than a radius of curvature of a leading edge segment of the second portion.

A fan includes a motor, a rotatable hub coupled to the motor, and at least one fan blade. The at least one fan blade includes a first end coupled to the rotatable hub, a second end, a leading edge, a trailing edge, a passage extending from the first end to the second end, and a winglet attached to the second end. At least one flexible strap extends through the passage of the at least one fan blade. The flexible strap is coupled at a first end to the rotatable hub and coupled at a second end to the winglet, such as to an inner portion thereof within the passage.

An axial flow fan includes a hub and a blade provided around the hub and having a leading edge and a trailing edge. The blade has a thickness portion. The thickness portion includes a first thickness portion located adjacent to the leading edge and a second thickness portion located adjacent to the trailing edge. A virtual circle centered on the rotation axis and passing through both the first thickness portion and the second thickness portion of the blade is a reference circle, an intersection at which the reference circle intersects an edge portion of the first thickness portion is a first intersection, an intersection at which the reference circle intersects an edge portion of the second thickness portion is a second intersection, an intersection of the reference circle and the leading edge is a first edge portion, an intersection of the reference circle and the trailing edge is a second edge portion, a straight line passing through the rotation axis and the first intersection is a thickness portion first straight line, a straight line passing through the rotation axis and the second intersection is a thickness portion second straight line, a straight line passing through the rotation axis and the first edge portion is an edge portion first straight line, a straight line passing through the rotation axis and the second edge portion is an edge portion second straight line, an angle between the thickness portion first straight line and the edge portion first straight line is a phase angle θ1, and an angle between the thickness portion second straight line and the edge portion second straight line is a phase angle θ2. The phase angle θ1 is larger than the phase angle θ2.

A ceiling fan assembly comprising a motor, a mount for coupling to a structure and for suspending the motor, and a ceiling fan blade comprising only a blade body for coupling to the motor, wherein the ceiling fan blade is formed from a molded pulp comprising at least one of paper fibers, plant fibers, or wood fibers.

A counter-rotating axial air moving device is disclosed. A front rotor includes a front hub, front first blades, a front annular sheet, front second blades, a front first radial zone and a front second radial zone. A rear rotor is disposed on a rear side of the front rotor and includes a rear hub, rear first blades, a rear annular sheet, rear second blades, a rear first radial zone and a rear second radial zone. A better performance is achieved by optimal matching designs of each radial partition, and the deterioration of vibration and noise is avoided.

An apparatus for safely enabling air filtering by temporarily joining a box fan to a replaceable air filter includes: (a) an air chamber frame with a rear portion that is configured to accommodate the replaceable air filter, (b) a frame stabilizing means that includes a front mounting platform which is configured to temporarily hold a box fan that is oriented to pull air through the filter, (c) a gasket that is configured to attach to the frame's front surface and minimize air flow around the gasket and into the frame, (d) a vent door located in the frame and configured to open to allow air to enter the frame's interior region when the filter is clogged, (e) an alarm mechanism attached to the vent door and configured to provide a signal when the door is been opened, and (f) an alarm device configured to receive the alarm mechanism's signal and provide an alarm that the air filter needs replacement.