Abstract: There is disclosed an inline axial flow fan including at least first and second axial flow fans and arranged in an inline manner along an axial direction of a rotational shaft of a rotational driving apparatus. A first flow control grid is arranged in a gas discharge side of the first axial flow fan, and a second flow control grid is arranged in a gas discharge side of the second axial flow fan. The first flow control grid has a stator blade having a smooth circular arc leading edge shape matching a circular arc shape of the stator blade of the first axial flow fan and a trailing edge shape extending in parallel with a gas flow direction. The second flow control grid has a stator blade having a smooth circular arc shape matching a circular arc shape of the stator blade of the second axial flow fan.

Abstract: Provided here is a counter-rotating axial flow fan with improved air flow-static pressure characteristics and reduced power consumption and noise compared to the related art. A plurality of struts are disposed to be stationary between a front impeller and a rear impeller in an air channel. A plurality of front blades are each formed of a swept-back blade, and a plurality of rear blades are each formed of a forward-swept blade.

Abstract: A counter-rotating axial flow fan with reduced noise at the target operating point achieved without modifying a front impeller, a rear impeller, or a middle stationary portion is provided. An annular rib including a projecting surface for generating turbulent flow is formed on an inner wall portion of a casing at a position off from the middle stationary portion to a side of the rear impeller, the projecting surface extending radially inwardly of the inner wall portion and extending continuously in the circumferential direction of the inner wall portion. A fluid striking the projecting surface for generating turbulent flow is partially disturbed to form a turbulent flow before entering an area in which the rear impeller is provided. The turbulent flow suppresses flow separation of a fluid flowing along the surfaces of rear blades of the rear impeller from the surfaces of the rear blades.

Abstract: A counter-rotating axial flow fan with improved characteristics and reduced noise compared to the related art can be provided. Defining the number of front blades as N, the number of stationary blades as M, and the number of rear blades as P, and defining the maximum axial chord length of the front blades as Lf, the maximum axial chord length of the rear blades as Lr, the outside diameter of the front blades as Rf, and the outside diameter of the rear blades as Rr, the counter-rotating axial flow fan satisfies the following two relationships: N?P>M; and Lf/(Rf×?/N)?1.25 and/or Lr/(Rr×?/P)?0.83.

Abstract: An axial-flow fan according to the present disclosure can increase the amount of the airflow and simultaneously reduce the noise level. A plurality of stationary blades 11A to 11D are curved, in a convex manner, toward a rotating direction of an impeller. The plurality of stationary blades 11A to 11D are generally inclined so that discharge-side edge portions 11d thereof are located more forward than suction-side edge portions 11c thereof in the rotating direction. An inclination angle ?4 of each of the plurality of stationary blades 11A to 11D in the vicinity of the external end portion 11a is larger than the inclination angle ?3 in the vicinity of the internal end portion 11b. The inclination angle is gradually changed from the vicinity of the external end portion 11a toward the vicinity of the internal end portion 11b.

Abstract: A counter-rotating axial flow fan in which the shape of stationary blades of a middle stationary portion is optimized to reduce noise is provided. Defining the maximum axial chord length of front blades as Lf, the maximum axial chord length of rear blades as Lr, and the maximum axial chord length of stationary blades as Lm, a relationship of Lm/(Lf+Lr)<0.14 is satisfied. Defining the maximum dimension between the blade chord for lower surfaces of the stationary blades and the lower surfaces as K1, the maximum axial chord length Lm of the stationary blades satisfies a relationship of Lm/K1>5.8.

Abstract: There is disclosed an inline axial flow fan including at least first and second axial flow fans and arranged in an inline manner along an axial direction of a rotational shaft of a rotational driving apparatus. A first flow control grid is arranged in a gas discharge side of the first axial flow fan, and a second flow control grid is arranged in a gas discharge side of the second axial flow fan. The first flow control grid has a stator blade having a smooth circular arc leading edge shape matching a circular arc shape of the stator blade of the first axial flow fan and a trailing edge shape extending in parallel with a gas flow direction. The second flow control grid has a stator blade having a smooth circular arc shape matching a circular arc shape of the stator blade of the second axial flow fan.

Abstract: Provided here is a counter-rotating axial flow fan with improved air flow-static pressure characteristics and reduced power consumption and noise compared to the related art. A plurality of struts are disposed to be stationary between a front impeller and a rear impeller in an air channel. A plurality of front blades are each formed of a swept-back blade, and a plurality of rear blades are each formed of a forward-swept blade.

Abstract: A counter-rotating axial flow fan in which the shape of stationary blades of a middle stationary portion is optimized to reduce noise is provided. Defining the maximum axial chord length of front blades as Lf, the maximum axial chord length of rear blades as Lr, and the maximum axial chord length of stationary blades as Lm, a relationship of Lm/(Lf+Lr)<0.14 is satisfied. Defining the maximum dimension between the blade chord for lower surfaces of the stationary blades and the lower surfaces as K1, the maximum axial chord length Lm of the stationary blades satisfies a relationship of Lm/K1>5.8.

Abstract: A counter-rotating axial flow fan with reduced noise at the target operating point achieved without modifying a front impeller, a rear impeller, or a middle stationary portion is provided. An annular rib including a projecting surface for generating turbulent flow is formed on an inner wall portion of a casing at a position off from the middle stationary portion to a side of the rear impeller, the projecting surface extending radially inwardly of the inner wall portion and extending continuously in the circumferential direction of the inner wall portion. A fluid striking the projecting surface for generating turbulent flow is partially disturbed to form a turbulent flow before entering an area in which the rear impeller is provided. The turbulent flow suppresses flow separation of a fluid flowing along the surfaces of rear blades of the rear impeller from the surfaces of the rear blades.

Abstract: A counter-rotating axial flow fan with improved characteristics and reduced noise compared to the related art can be provided. Defining the number of front blades as N, the number of stationary blades as M, and the number of rear blades as P, and defining the maximum axial chord length of the front blades as Lf, the maximum axial chord length of the rear blades as Lr, the outside diameter of the front blades as Rf, and the outside diameter of the rear blades as Rr, the counter-rotating axial flow fan satisfies the following two relationships: N?P>M; and Lf/(Rf×?/N)?1.25 and/or Lr/(Rr×?/P)?0.83.

Abstract: A first motor rotates, in one of two rotating directions, the first impeller including a plurality of front blades in a suction opening portion of a housing. The second motor rotates, in the other rotating direction opposite to the one rotating direction, the second impeller including a plurality of rear blades in a discharge opening portion of the housing. A plurality of stationary blades are arranged between the first impeller and the second impeller in the housing. When the number of the front blades is N, that of the stationary blades is M, and that of the rear blades is P, their relationship is defined as N>P>M. A length L1 of the front blades measured in an axial direction is set longer than a length L2 of the rear blades measured in the axial direction.

Abstract: The present invention provides an axial flow fan capable of increasing an air volume and static pressure more than conventional axial flow fans. A plurality of rotary blades 5 are disposed in a circumferential direction of a rotary shaft 8 at equidistant intervals. A plurality of stationary blades 11 are disposed in the vicinity of a discharge opening 16 of an air channel portion 19 of a housing 3. The stationary blades are disposed in the circumferential direction of the rotary shaft 8 at equidistant intervals. The number of the rotary blades is seven (7) and the number of the stationary blades 11 is eight (8).

Abstract: The present invention provides an axial flow fan capable of increasing an air volume and a static pressure more than conventional axial flow fans, and also capable of reducing generation of noise. A guide wall portion 33 is provided to form a guide groove 31 between the guide wall portion 33 and one stationary blade 11. The one stationary blade 11 is disposed in the vicinity of a lead wire engaging portion 25 provided at a housing 3. The guide groove 31 receives a plurality of lead wires 10 and guides the lead wires 10 to the lead wire engaging portion 25. When the guide wall portion 33 is provided and the lead wires 10 are received in the guide groove 31, presence of the lead wires 10 may have less adverse effect on the air volume and the static pressure, and may generate less noise.

Abstract: A first motor rotates, in one of two rotating directions, the first impeller including a plurality of front blades in a suction opening portion of a housing. The second motor rotates, in the other rotating direction opposite to the one rotating direction, the second impeller including a plurality of rear blades in a discharge opening portion of the housing. A plurality of stationary blades are arranged between the first impeller and the second impeller in the housing. When the number of the front blades is N, that of the stationary blades is M, and that of the rear blades is P, their relationship is defined as N>P>M. A length L1 of the front blades measured in an axial direction is set longer than a length L2 of the rear blades measured in the axial direction.

Abstract: The present invention provides an axial flow fan capable of increasing an air volume and static pressure more than conventional axial flow fans. A plurality of rotary blades 5 are disposed in a circumferential direction of a rotary shaft 8 at equidistant intervals. A plurality of stationary blades 11 are disposed in the vicinity of a discharge opening 16 of an air channel portion 19 of a housing 3. The stationary blades are disposed in the circumferential direction of the rotary shaft 8 at equidistant intervals. The number of the rotary blades is seven (7) and the number of the stationary blades 11 is eight (8).

Abstract: A first motor 25 rotates, in one of two rotating directions, the first impeller 7 including a plurality of front blades 28 in a suction opening portion 15 of a housing 59. The second motor 49 rotates, in the other rotating direction opposite to the one rotating direction, the second impeller 35 including a plurality of rear blades 51 in a discharge opening portion 57 of the housing 59. A plurality of stationary blades 61 are arranged between the first impeller 7 and the second impeller 35 in the housing 59. When the number of the front blades 28 is N, that of the stationary blades 61 is M, and that of the rear blades 51 is P, their relationship is defined as N>P>M. A length L1 of the front blades 28 measured in an axial direction is set longer than a length L2 of the rear blades 51 measured in the axial direction.

Abstract: The present invention provides an axial flow fan capable of increasing an air volume and a static pressure more than conventional axial flow fans, and also capable of reducing generation of noise. A guide wall portion 33 is provided to form a guide groove 31 between the guide wall portion 33 and one stationary blade 11. The one stationary blade 11 is disposed in the vicinity of a lead wire engaging portion 25 provided at a housing 3. The guide groove 31 receives a plurality of lead wires 10 and guides the lead wires 10 to the lead wire engaging portion 25. When the guide wall portion 33 is provided and the lead wires 10 are received in the guide groove 31, presence of the lead wires 10 may have less adverse effect on the air volume and the static pressure, and may generate less noise.

Abstract: An axial-flow fan according to the present disclosure can increase the amount of the airflow and simultaneously reduce the noise level. A plurality of stationary blades 11A to 11D are curved, in a convex manner, toward a rotating direction of an impeller. The plurality of stationary blades 11A to 11D are generally inclined so that discharge-side edge portions 11d thereof are located more forward than suction-side edge portions 11c thereof in the rotating direction. An inclination angle ?4 of each of the plurality of stationary blades 11A to 11D in the vicinity of the external end portion 11a is larger than the inclination angle ?3 in the vicinity of the internal end portion 11b. The inclination angle is gradually changed from the vicinity of the external end portion 11a toward the vicinity of the internal end portion 11b.

Abstract: A first motor 25 rotates, in one of two rotating directions, the first impeller 7 including a plurality of front blades 28 in a suction opening portion 15 of a housing 59. The second motor 49 rotates, in the other rotating direction opposite to the one rotating direction, the second impeller 35 including a plurality of rear blades 51 in a discharge opening portion 57 of the housing 59. A plurality of stationary blades 61 are arranged between the first impeller 7 and the second impeller 35 in the housing 59. When the number of the front blades 28 is N, that of the stationary blades 61 is M, and that of the rear blades 51 is P, their relationship is defined as N>P>M. A length L1 of the front blades 28 measured in an axial direction is set longer than a length L2 of the rear blades 51 measured in the axial direction.