Patent ID: 11859635
Assignee: DAIKIN INDUSTRIES, LTD.
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC F | IPC F

Claim 0:
1. An axial-flow fan comprising:
a hub; and
blades disposed on an outer peripheral surface of the hub and spaced apart from each other in a circumferential direction, wherein
the hub comprises:
an outer wall having a tubular shape;
an inner wall having a tubular shape and being disposed radially inward of the outer wall;
a boss to which a shaft is mounted and that is disposed radially inward of the inner wall;
a first sidewall connecting an end portion of the outer wall that is closer to a first side in a rotation axis direction of the hub with an end portion of the inner wall that is closer to the first side in the rotation axis direction;
a second sidewall connecting the end portion of the inner wall with an end portion of the boss that is closer to the first side in the rotation axis direction;
a first rib connecting an inner peripheral surface of the inner wall with an outer peripheral surface of the boss;
a second rib adjacent to the first rib in the circumferential direction and that connects the inner peripheral surface of the inner wall with the outer peripheral surface of the boss; and
a third rib connecting an inner peripheral surface of the outer wall with an outer peripheral surface of the inner wall and that has a radially inner end portion disposed between a radially outer end portion of the first rib and a radially outer end portion of the second rib in the circumferential direction, wherein
the first rib and the second rib are disposed in a radial direction of the hub, and
an angle θ between the first rib and the second rib satisfies θ≤360/2N where N represents a number of the blades, and

the hub further comprises:
a first set including a combination of the first rib and the second rib; and
a second set including a combination of the first rib and the second rib that are different from the first rib and the second rib in the first set and that is adjacent to the first set in the circumferential direction, and

an angle between the first set and the second set is larger than an angle between the first rib and the second rib in each of the first set and the second set.