A dual stage blower assembly includes a first fan configured to rotate about the rotational axis and including a first plurality blades. The first plurality of blades include a plurality of backward curved blades. The dual stage blower assembly also includes a second fan circumscribing the first fan and configured to rotate about the rotational axis. The second fan includes a second plurality of blades, wherein the second plurality of blades include one of a plurality of forward curved blades, a plurality of a radial blades, or a plurality of backward curved blades. At least one motor is coupled to the first fan and the second fan and configured to rotate the first fan and the second fan about the rotational axis.

A blower for providing a supply of air at positive pressure in the range of approximately 2 cmH.sub.2O to 30 cmH.sub.2O includes a motor, at least one impeller, and a stationary component. The stationary component includes an inlet and an outlet. The motor, the impeller, the inlet and outlet are co-axial.

A blower for a breathing apparatus has a diffuser for increasing static pressure and/or reducing noise and/or mitigating pressure instabilities and/or managing reverse flow.

A head-mountable flow generator is configured to deliver a flow of breathable gas at a continuously positive pressure with respect to ambient air pressure to a patient interface in communication with an entrance to a patient's airways including at least an entrance of the patient's nares, while the patient is sleeping, to ameliorate sleep disordered breathing. The flow generator includes a motor, an impeller assembly and housing that encases the motor and the impeller assembly. The housing is configured to be mounted on the patient's head and comprises an inlet to receive the flow of breathable gas and a pair of opposing outlets to deliver the flow of breathable gas. In addition, the impeller assembly is configured to pressurize the flow of breathable gas received from the inlet, and the housing is configured to convey the pressurized flow of breathable gas through both outlets.

A vacuum cleaner assembly configured to be mounted in a vehicle. The vacuum cleaner assembly including a vacuum unit configured to draw a vacuum, a canister assembly configured to collect debris and coupled to the vacuum unit, a hose junction configured to serve as a pathway for debris, and a chassis connecting the hose junction to the canister assembly. A pathway through the vacuum cleaner assembly may turn 180 degrees in the hose junction. A dirty air port of the canister assembly may be disposed at an angle relative to a surface of the chassis to facilitate placement and removal of the canister assembly.

A blower for providing a supply of air at positive pressure in the range of approximately 2 cm H2O to 30 cm H2O includes a motor, at least one impeller, and a stationary component. The stationary component includes an inlet and an outlet. The motor, the impeller, the inlet and outlet are co-axial.

A blower, including: a volute including air inlets and an air outlet; a wind wheel disposed in the volute; and air collectors. Each air collector includes a curved air guide. The air inlets are disposed at two sides of the wind wheel, respectively. The air collectors correspond to the air inlets. The curved air guide extends into the volute, and the inner diameter of the curved air guide decreases stepwise. The relationship between a minimum inner diameter D0 of the curved air guide and an inner diameter D1, an outer diameter D2 of the wind wheel fulfills the following formula: D1+(D2D1)D0D1+(D2D1). An exhaust fan that includes the blower is also provided.

A pump assembly is provided for use with an inflatable product. The inflatable product has a chamber having an air inlet and an air outlet. The pump assembly has a pump unit that is positioned inside the chamber for inflating and deflating the chamber, the pump unit having at least one motor that is operatively coupled to a first blower and a second blower, with the first blower fluidly coupled to the air inlet and the second blower fluidly coupled to the air outlet. The chamber is inflated by intake of air through the air inlet to the first blower and then into the chamber, and the chamber is deflated by drawing air from the chamber to the second blower and then out of the chamber through the air outlet.

A fan module includes a first casing, a driving motor disposed in the first casing, a first rotor connected to the first driving motor, a second casing, a second rotor pivotally configured in the second casing, at least one guiding member and a shift apparatus connected to the first casing and the second casing, the first rotor includes a first rotating shaft and a plurality of first blades, the second rotor includes a second rotating shaft and a plurality of second blades, the guiding member is disposed on the first blade and the second blade. The whole height of the blade is adjusted by adjusting the distance between the two group blades, then the efficiency of the fan is improved effectively to optimize the noise level and the air flow.

A fan with airfoil blades is provided for a regenerative air vacuum street sweeper. The blades are formed using cut and pressed upper and lower panels which are welded at a forward edge to a rod to form the airfoil leading edge and welded at the rear edges to form the airfoil trailing edge. Pins extend laterally outwardly from the rod for mounting each blade in corresponding holes in the front and rear plates of the fan housing. The side edges of the blade are welded to the plates at a 9-11? angle of attack. The airfoil blades allow for reduced size, horse power, noise, and manufacturing and shipping costs.