Fujitsu General Limited

Kazuya Funada

Hirotaka Sawada

Junya Tanaka

Kenji Komine

Toshiyuki Fuji

Shunji Itakura

Ken Horiguchi

Sota Shimada

A propeller fan includes a hub that has a side surface around a central axis, and blades that are provided on the side surface, wherein a blade of the blades includes an inner peripheral portion located on a side of a base, and an outer peripheral portion located on a side of an outer edge, the outer peripheral portion is formed as one blade, the inner peripheral portion includes blade elements arranged at a predetermined interval, a ratio r/R of a radius r which is a distance from the central axis to the outer peripheral portion and a radius R which is a distance from the central axis to the outer edge is 0.4 or less, and when a wind speed at the outer peripheral portion is Vand a wind speed at the inner peripheral portion is V, a relational formula of V&#x2264;V&#xd7;2.0 is established.

Propeller fan

When an apex of a first blade element projecting from the positive pressure surface is A, a distance from the center axis to the apex A is r, and a point having the distance r from the center axis on a front edge in the rotation direction of the first blade element is B, the first blade element among the blade elements that is arranged on a front edge side in the rotation direction of the blade, is formed to have a blade angle equal to or larger than a predetermined first angle and equal to or smaller than a second angle that is larger than the first angle, the blade angle being formed by a direction along a chord of the first blade element along a direction that connects the apex A with the point B, and a plane orthogonal to the center axis.

A propeller fan includes: a hub having a side surface about a center axis; and a plurality of blades provided on the side surface of the hub. Each blade includes an inner peripheral portion positioned closer to a base portion of the each blade connected to the hub, and an outer peripheral portion positioned closer to an outer edge of the each blade. A ratio r/R between a radius r as a distance from the center axis to a boundary between the inner peripheral portion and the outer peripheral portion and a radius R as a distance from the center axis to the outer edge of each blade is equal to or lower than 0.4. A relational expression of V&#x3c;V&#xd7;1.3 is satisfied, where an air velocity at the outer peripheral portion is Vand an air velocity at the inner peripheral portion is V

A first opening, which passes through the blade surface part from a negative pressure side toward a positive pressure side, is provided between the first blade element and the second blade element on the blade surface part. A space between an outer edge of the first blade element extended from the side surface toward an outer edge side of the blade, and an outer edge of the second blade element extended from the side surface toward the outer edge side of the blade on the positive pressure surface side, is opened from the side surface in a radial direction of the blade surface part, so that an air current coming from the negative pressure side toward the positive pressure side through the first opening, flows from the first opening toward the outer edge side of the blade along the positive pressure surface.

On the blade surface part, a first opening passing through the blade surface part from a negative pressure side toward a positive pressure side is provided between the first blade element and the second blade element. A chord length of the first blade element along a direction connecting the apex A with the point B, is equal to or larger than a chord length of the second blade element along a direction connecting an apex C with a point D.

An inner peripheral blade projects from the positive pressure surface of the blade surface part toward a positive pressure side, includes a front edge in a rotation direction of the inner peripheral blade that is formed in a curved shape to be separated from a reference line toward the front edge side in the rotation direction of the blade, the reference line connecting a lower end positioned on the positive pressure surface at a base end of the inner peripheral blade connected to the side surface of the hub with an outer edge of the inner peripheral blade that is extended from the side surface toward an outer edge side of the blade and positioned on the positive pressure surface, and satisfies H/L&#x2265;0.1, where L is a length of the reference line and H is a maximum value of a distance between the reference line and the front edge of the inner peripheral blade.

A propeller fan includes a hub and a plurality of blades, wherein the blade has a plurality of blade elements branching on a way from an outer peripheral portion to an inner peripheral portion, the plurality of blade elements form a hole which is a flow path for airflow, between the adjacent blade elements, have a first blade element on an upstream side and a second blade element on a downstream side to be adjacent to the first blade element which branch at a branch point, and include an extension portion as a part of the first blade element, on a trailing edge of the first blade element from the branch point to a side surface of the hub, and at least a part of a leading edge of the second blade element overlaps with a rotation orbit of the extension portion with a central axis as a rotation center.

A rotary compressor includes: a closed upright cylindrical compressor housing including an upper portion provided with a discharge section of refrigerant and a body portion provided with an intake section of the refrigerant; a compression section disposed at a lower part in the compressor housing and configured to compress the refrigerant suctioned by the intake section to discharge the refrigerant from the discharge section; and a motor disposed at an upper part in the compressor housing and configured to drive the compression section. The motor has a rotor disposed on an inner side and a stator disposed on an outer side, the refrigerant is HFO1123 refrigerant or a refrigerant mixture containing the HFO1123 refrigerant, and an inner welded portion formed by welding using flux is provided within a projection area of the rotor at the upper portion of the compressor housing.

Rotary compressor and refrigeration cycle device

A heat exchanger includes: a heat transfer pipe in which refrigerant flows; and a spiral groove formed at an inner peripheral surface of the heat transfer pipe. A height of an inner wall of the groove in a radial direction of the heat transfer pipe is equal to or greater than 0.1 [mm], and when a wetted edge length of the heat transfer pipe is S, an inclination angle between a pipe axis direction of the heat transfer pipe and a longitudinal direction of the groove in a section of the heat transfer pipe parallel with the pipe axis direction is &#x3b8;, and a length of the heat transfer pipe is L, the inclination angle &#x3b8; is an acute angle, and a wetted area S&#xd7;L/cos &#x3b8; of the heat transfer pipe satisfies S&#xd7;L/cos &#x3b8;&#x2265;0.5 [m2].

Growing community of inventors

Kanagawa, Japan

Kazuya Funada