EP-4737737-A1 - AXIAL FLOW FAN AND FAN STATOR

Abstract

Provided are an axial-flow fan and a stator that produce effects including high efficiency and a flow-straightening effect by providing a proper configuration of the fan and an adjusted number of the blades and thereby preventing air flows from changing suddenly, in the axial-flow fan made of plastic and separately including an outer ring, a hub positioned at a center of the outer ring, and a plurality of blades between the outer ring and the hub. The axial-flow fan made of plastic and separately including an outer ring, a hub positioned at the center of the outer ring, and a plurality of blades between the outer ring and the hub is characterized in that each of the blades curves rearward from its base portion on the central support member to a middle part of the blade and further curves forward from the middle part to the outer ring, the blade is wide and an actual length thereof is long, and the blade is twisted at a desired inclination angle.

Inventors

• YAMAMOTO, SHINICHIRO
• IIDA, YOSHINOBU

Assignees

• Usui Co., Ltd.

Dates

Publication Date

20260506

Application Date

20240628

Claims (3)

1. An axial-flow fan made of plastic, separately comprising a circular outer ring, a hub having a circular central support member positioned at a center of the outer ring, and a plurality of blades arranged between the outer ring and the hub, wherein each of the blades curves rearward from its base portion on the central support member to a middle part of the blade and further curves forward from the middle part to the outer ring, the blade is wide and an actual length thereof is long, and the blade is twisted at a desired inclination angle.
2. The axial-flow fan according to claim 1, wherein the circular outer ring, the hub having the circular central support member, and the blades are integrally formed.
3. A fan stator of fixing an axial-flow fan, comprising stays radially arranged between a mount positioned at a center and an annular outlet bell, wherein the stays have a cross-sectional shape aligned with a vector at an outlet side of the fan and are twisted at a desired inclination angle in a rotational direction of the fan.

Description

Technical Field The present invention relates generally to an engine cooling axial-flow fan, which is rotationally driven for cooling an automobile engine and the like (including applications for cooling an EV battery, motor, FCV stack, and auxiliary equipment; hereinafter simply referred to as "engine cooling fan"), and to a fan stator for fixing via an electric motor that drives the engine cooling fan. Background Art Generally, engine cooling axial-flow fans that are rotationally driven are used in vehicles such as automobiles for cooling purposes. Such cooling fans are required to have a configuration that satisfies various requirements, such as low noise, high efficiency, compactness, and the ability to achieve favorable pressure and flow rate values. Hence, to meet these requirements, various configurations of the fans have been heretofore proposed. For example, there has been known an axial-flow fan having fan blades that radially extend from the outer circumstance of a cylindrical hub having a substantially T-shaped cross section, in which a curved surface on the leading-edge side of each blade is formed toward the root side of the blade from the side of the axial end surface (see Patent Literature 1). However, due to the increasing demand for electric vehicles (EVs), cooling fans driven by electric motors rather than by engine rotational power have been required recently. In the case of a fan driven by the electric motor or other rotary driving means, the fan and a stator are necessary and the performance is affected by the configuration or structure of the fan and the stator. Thus, for the fan stator for fixing via an electric motor driving an engine cooling fan, for example, there has been known one having a structure where stays with an axially-flat-plate shape are radially arranged between a mount positioned at the center portion and an annular outlet bell (see Patent Literature 2). Citation List Patent Literature Patent Literature 1: JP 4994975 B2Patent Literature 2: JP 2012-229693 A Summary of Invention Technical Problem However, the conventional engine cooling axial-flow fan and stator have problems as described below. That is, for example, an engine cooling fan dedicated to an output of 500 W has a drawback that the distance for changing the airflows generated by the fan is short because of short fan blades, which causes pressure resistance on the surfaces of the fan blades, thereby resulting in a decrease in efficiency. Further, a stator dedicated to the engine cooling fan with the 500 W output has a drawback that, because its stays themselves have a similar sectional shape to the fan blades but the airflows at an outlet of the fan do not match the shape of stator vanes, the airflows generated by the fan are obstructed, thereby increasing the driving torque. In addition, an engine cooling fan dedicated to an output of 1 kW has a drawback that, because the fan typically has 11 blades, the airflows generated by the upstream and downstream blades interfere with airflows around the blades, and besides, the distance for deflecting the airflows is also short because of short blades, which causes pressure resistance on the blade surfaces, thereby resulting in a decrease in efficiency. Furthermore, a stator dedicated to the engine cooling fan with the 1 kW output has a drawback that, because of the stays having the axially-flat-plate shape, the airflow generated by the fan is obstructed, thereby increasing the driving torque. The present invention has been made to solve the drawbacks of the conventional axial-flow fan and fan stator. And, the invention aims to provide an axial-flow fan and a fan stator that produce effects including high efficiency and a flow-straightening effect by providing a proper configuration of the fan and an adjusted number of the blades and thereby preventing air flows from changing suddenly, in the axial-flow fan made of plastic and separately including an outer ring, a hub positioned at a center of the outer ring, and a plurality of blades between the outer ring and the hub. Solution to Problem The axial-flow fan (a motor-driven fan) made of plastic according to the present invention separately includes a circular outer ring, a hub having a circular central support member positioned at a center of the outer ring, and a plurality of blades arranged between the outer ring and the hub. The axial-flow fan is characterized in that each of the blades curves rearward from its base portion on the hub having the central support member to a middle part of the blade and further curves forward from the middle part to the outer ring, and the blade is wide and an actual length of the blade is long, and further the blade is twisted at a desired inclination angle. In addition, the axial-flow fan is characterized in that the circular outer ring, the hub having the circular central support member, and the blades may be integrally formed. Further, the fan stator for fixing the axial-flow f