Abstract: Blades (20a to 20c) of a propeller fan (10) have different circumferential pitches ?1, ?2, and ?3. 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.

Abstract: In a blade of a propeller fan, an inclination angle (?) is made by a straight line passing through an outer circumferential side end and an inner circumferential side end of a radial cross section of the blade with a second plane orthogonal to a center axis of a hub. In a blade end of the blade, one end in front of the other end viewed in the rotation direction of the propeller fan is a leading blade end, while the other end behind the leading blade end is a trailing blade end. The blade is shaped such that the inclination angle (?) monotonically increases, in the direction from the intermediate position toward the trailing blade end, in an area extending from an intermediate position between the leading blade end and the trailing blade end to the trailing blade end.

Abstract: In a blade of a propeller fan, a position on a chord line where the camber becomes maximum is set as a maximum camber position A, and a ratio of a distance d between a leading edge and the maximum camber position A to a chord length c is set as a maximum camber position ratio. The end portion on the hub side of the blade is set as a blade root, and the end portion on the outer circumferential side of the blade is set as a blade end. In the blade, the maximum camber position ratio monotonically increases in the direction from the reference blade cross section located between the blade root and the blade end toward the blade end and becomes maximum at the blade end. Thus, fan efficiency of the propeller fan is improved.

Abstract: In a blade of a propeller fan, an inclination angle (?) is made by a straight line passing through an outer circumferential side end and an inner circumferential side end of a radial cross section of the blade with a second plane orthogonal to a center axis of a hub. In a blade end of the blade, one end in front of the other end viewed in the rotation direction of the propeller fan is a leading blade end, while the other end behind the leading blade end is a trailing blade end. The blade is shaped such that the inclination angle (?) monotonically increases, in the direction from the intermediate position toward the trailing blade end, in an area extending from an intermediate position between the leading blade end and the trailing blade end to the trailing blade end.

Abstract: Blades (20a to 20c) of a propeller fan (10) have different circumferential pitches ?1, ?2, and ?3. 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.

Abstract: In a blade of a propeller fan, a position on a chord line where the camber becomes maximum is set as a maximum camber position A, and a ratio of a distance d between a leading edge and the maximum camber position A to a chord length c is set as a maximum camber position ratio. The end portion on the hub side of the blade is set as a blade root, and the end portion on the outer circumferential side of the blade is set as a blade end. In the blade, the maximum camber position ratio monotonically increases in the direction from the reference blade cross section located between the blade root and the blade end toward the blade end and becomes maximum at the blade end. Thus, fan efficiency of the propeller fan is improved.

Abstract: A propeller fan includes a rotary blade hub driven in rotation about a rotation axis, and a rotary blade installed at an outer periphery of the rotary blade hub. The rotary blade includes a rotary blade body protruding from an outer peripheral surface of the rotary blade hub, and a rib formed on an outer peripheral edge portion of a pressure surface of the rotary blade body so as to extend along an outer peripheral edge of the rotary blade body.

Abstract: A propeller fan includes a rotary blade hub driven in rotation about a rotation axis, and a rotary blade installed at an outer periphery of the rotary blade hub. The rotary blade includes a rotary blade body protruding from an outer peripheral surface of the rotary blade hub, and a rib formed on an outer peripheral edge portion of a pressure surface of the rotary blade body so as to extend along an outer peripheral edge of the rotary blade body.

Abstract: A centrifugal fan includes a hub, a plurality of blades, and a shroud. The blades each have a curved part that is curved to incline toward a side on which air impinges when a connected end connected to an inwardly protruding portion of the shroud moves in a rotating direction of the centrifugal fan. The hub includes a hub-side diffuser ring that protrudes radially outward of the blades. The shroud includes a shroud-side diffuser ring that protrudes radially outward of the blades.

Abstract: A multi-blade centrifugal fan for preventing circular flows in the end portions of an impeller in the axial direction is provided in a simple structure. The multi-blade centrifugal fan is formed of a fan casing of a scroll type and a multi-blade centrifugal impeller. The fan casing has a bellmouth which becomes an air intake. The multi-blade centrifugal impeller has a number of annularly arranged blades inside the fan casing. The centrifugal impeller draws in air through the intake, which faces the bellmouth, and blows out the air in the centrifugal direction through the blades. A retainer ring is provided in an outer peripheral end portion of the impeller. A cylindrical body is integrally provided in such a manner as to extend from the outer end of the retainer ring, so that circular flows toward the intake side are prevented in the end portions of the impeller.

Abstract: The content decrypting apparatus 2000 of the present invention stores a chaining value generated during decryption of the last ciphertext block of a chunk in association with a content type and a frame number to an inter-chunk chaining value holding unit 216. When decrypting the first ciphertext block of a chunk, and in case where a chaining value is stored to the inter-chunk chaining value holding unit 216 in association with a content type and a frame number corresponding to the chunk, the content decrypting apparatus decrypts the first ciphertext block of the chunk using the chaining value. Hence, the content decrypting apparatus pertaining to the present invention is capable of correctly decrypting data streams having a data structure in which ciphertext chunks belonging to a first encrypted frame are disposed in between two ciphertext chunks belonging to a second encrypted frame.

Abstract: A multi-blade centrifugal fan for preventing circular flows in the end portions of an impeller in the axial direction is provided in a simple structure. The multi-blade centrifugal fan is formed of a fan casing 1 of a scroll type and a multi-blade centrifugal impeller 2. The fan casing 1 has a bellmouth 4 which becomes an air intake. The multi-blade centrifugal impeller 2 has a number of annularly arranged blades 6 inside the fan casing 1. The centrifugal impeller 2 draws in air through the intake 7, which faces the bellmouth 4, and blows out the air in the centrifugal direction through the blades 6. A retainer ring 10 is provided in an outer peripheral end portion of the impeller 2. A cylindrical body 11 is integrally provided in such a manner as to extend from the outer end of the retainer ring 10, so that circular flows toward the intake side are prevented in the end portions of the impeller 2.