Patent ID: 11920608
Assignee: MITSUBISHI ELECTRIC CORPORATION
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. An axial fan, comprising:
a hub having a rotation shaft and configured to be driven to rotate; and
blades provided to the hub, the blades each having a front edge portion and a rear edge portion, the front edge portion of each blade being further forward in a direction in which the blades rotate than the rear edge portion of the blade,
in a first blade section that is a first section of a first portion between the front edge portion and the rear edge portion of each of the blades along the direction in which the blades rotate, the first blade section being a first area of each of the blades that is further inward than an outer periphery edge portion that is a most radially outer periphery in each of the blades, the blades each having a projection portion and a first recess portion,
the projection portion projecting from a first portion of a pressure surface of each of the blades,
the first recess portion receding from a second portion of the pressure surface that is between the projection portion and the rear edge portion,
in a second blade section that is a second section of a portion between the front edge portion and the rear edge portion of each of the blades along the direction in which the blades rotate, the second blade section being further radially outward than the projection portion, the second blade section being a second area of each of the blades that is further inward than the outer periphery edge portion, the blades each have an outer periphery recess portion receding from a third portion of the pressure surface that is between the front edge portion and the rear edge portion in a whole of each of the blades, the projection portion having a projection top that is a top of the projection portion and is closer to the rear edge portion than is a center between the front edge portion and the rear edge portion in the first blade section,
wherein the blades each have a second recess portion that is entirely concave from a fourth portion of the pressure surface that is from the projection portion to the front edge portion in the first blade section.