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EP-4001661-B1 - AXIAL FLOW FAN, AIR CONDITIONING OUTDOOR UNIT AND AIR CONDITIONER

EP4001661B1EP 4001661 B1EP4001661 B1EP 4001661B1EP-4001661-B1

Inventors

  • GAO, Wendong

Dates

Publication Date
20260506
Application Date
20190821

Claims (13)

  1. An axial flow fan (100) comprising: an axial flow impeller (1) comprising: a hub (11) having a shaft hole; and a blade (12) arranged at an outer peripheral wall of the hub (11); a motor (2) driving the axial flow impeller (1) to rotate, and comprising: a motor body (21); and a motor shaft (22) connected to the motor body (21) and engaged in the shaft hole; and a resistance member (3) arranged at the hub (11) and close to a free end (221) of the motor shaft (22), wherein a stiffness of the resistance member (3) is greater than a stiffness of the hub (11); and wherein the resistance member (3) is annular and sleeved on an outer peripheral side of the motor shaft (22); characterized in that an inner peripheral wall of the resistance member (3) is spaced apart from an outer peripheral wall of the motor shaft (22) in a direction perpendicular to the motor shaft (22).
  2. The axial flow fan (100) according to claim 1, wherein the stiffness of the resistance member (3) is greater than a stiffness of the motor shaft (22).
  3. The axial flow fan (100) according to claim 1 or 2, wherein the resistance member (3) is a metallic member or a ceramic member, and/or the stiffness of the resistance member (3) is in a range from 0.8×10 7 N/m to 1.5×10 7 N/m.
  4. The axial flow fan (100) according to any one of claims 1 to 3, wherein an annular mounting groove is formed on an inner peripheral wall of the shaft hole, and the resistance member (3) is accommodated in the mounting groove.
  5. The axial flow fan (100) according to claim 4, wherein the mounting groove penetrates an end surface of the hub (11) close to the free end (221) of the motor shaft (22) along an axial direction.
  6. The axial flow fan (100) according to claim 5, wherein an end surface of the resistance member (3) close to the free end (221) of the motor shaft (22) is flush with the end surface of the hub (11) close to the free end (221) of the motor shaft (22).
  7. The axial flow fan (100) according to any one of claims 1 to 6, comprising: a locknut (4) connected to the free end (221) of the motor shaft (22) through threads, the locknut (4) being arranged at a side of the resistance member (3) close to the free end (221) of the motor shaft (22) and the locknut (4) abutting against the resistance member (3).
  8. The axial flow fan (100) according to claim 7, wherein the resistance member (3) and the locknut (4) are formed in one piece.
  9. The axial flow fan (100) according to claim 7 or 8, wherein a projection of the locknut (4) on a reference surface is a first projection, a projection of the resistance member (3) on the reference surface is a second projection, an outer contour of the first projection is located within an outer contour of the second projection, wherein the reference surface is perpendicular to a central axis of the motor shaft (22).
  10. The axial flow fan (100) according to any one of claims 1 to 9, wherein a length of the resistance member (3) in an axial direction of the motor shaft (22) ranges from 3mm to 6mm.
  11. The axial flow fan (100) according to any one of claims 1 to 10, wherein the resistance member (3) is embedded in the hub (11) through injection molding.
  12. An air conditioning outdoor unit comprising an axial flow fan (100) according to any one of claims 1 to 11.
  13. An air conditioner, comprising: an air conditioning indoor unit; and an air conditioning outdoor unit according to claim 12.

Description

TECHNICAL FIELD The present disclosure relates to the field of air treatment devices and, more particularly, to an axial flow fan, an air conditioning outdoor unit, and an air conditioner. BACKGROUND For axial flow impellers in the related art, blades thereof are usually thinned or other solutions are adopted to reduce the weight of an impeller and hence reduce the load of a motor. The impeller and a motor shaft are positioned with respect to each other via cooperation between the motor shaft and a hub and are tightened via a locknut. The impeller may have an increased resistance due to the reduced mass thereof, and the blades are subjected to different axial forces during the rotation of the impeller, such that the impeller may operate in an unbalanced state. In addition, since the axial flow impeller has poor performance against unbalanced excitation, the motor shaft may be subjected to great unbalanced excitation, which in turn results in the unbalance of the motor, thereby causing the motor to produce a lot of noise. The cooling fan and motor attachment system disclosed in US 5 871 335 A comprises a cooling fan and a motor, wherein an adaptor plate is used to connect the cooling fan to a shaft of the motor. In particular, a surface of a hub of the cooling fan and a surface of the adaptor plate that facing each other after assembly, are both provided with special patterns that matches each other, such that the adaptor plate can be "switch-lock" to the hub of the cooling fan. Besides, the adaptor plate has a bore to attach to the shaft of the motor, preferably by shrink fitting between the bore and the shaft of the motor. The preferable manufacturing methods of the cooling fan and the adaptor plate, and correspondingly, the appropriate materials to be used for the preferable manufacturing methods are also mentioned. JP 2017 141729 A depicts a blower having a blower fan and a motor, wherein a support plate is integrally molded in a front end side in an axial direction of the blower fan, and an attachment hole is provided on the support plate. A rotating shaft of the motor is provided with a D-cut surface, which is engaging with an engaging face of the attachment hole on the support plate, and consequently, the support plate helps transmitting the rotational torque input from a rotating shaft of the motor to the blower. US 2011 /206521 A1 describes a rotating part assembly for motor comprising a hub, a shaft, and a holding member that prevents the disengagement of the hub from the shaft, wherein the shaft penetrates an assembly channel on the hub, and the shaft engages with a lateral wall of the assembly channel in a close-fitting manner. Particularly, an enhancing member is provided in the hub and forms part of the lateral wall of the assembly channel. CN 208 918 906 U provides an axial flow wind wheel comprising a hub, blades distributed around the outer peripheral wall of the hub, and a metal piece embedded in the hub. A motor shaft is configured to penetrate through, firstly, a first shaft hole provided on the hub, and subsequently, a second shaft hole provided on the metal piece, wherein the diameter of the second shaft hole is smaller than the first shaft hole, and wherein the motor shaft is provided with an annular step surface corresponding to the diameters of the first shaft hole and the second shaft hole, so as to facilitating the axially positioning of the motor shaft and the axial flow wind. SUMMARY The present disclosure aims at solving at least one of the technical problems in the related art. In this regard, the present disclosure provides an axial flow fan, which generates less noise during operation. The present disclosure further provides an air conditioning outdoor unit comprising the above axial flow fan. The present disclosure further provides an air conditioner comprising the above air conditioning outdoor unit. According to the invention, an axial flow fan is provided. The axial flow fan comprises: an axial flow impeller comprising a hub and a blade arranged at an outer peripheral wall of the hub, the hub having a shaft hole; a motor driving the axial flow impeller to rotate, comprising a motor body and a motor shaft connected to the motor body, wherein the motor shaft is engaged in the shaft hole; and a resistance member arranged at the hub and close to a free end of the motor shaft. A stiffness of the resistance member is greater than a stiffness of the hub, and the resistance member is annular and sleeved on an outer peripheral side of the motor shaft. An inner peripheral wall of the resistance member is spaced apart from an outer peripheral wall of the motor shaft in a direction perpendicular to the motor shaft. In the axial flow fan according to the invention, by arranging the resistance member on the hub and close to the free end of the motor shaft and setting the stiffness of the resistance member to be greater than the stiffness of the hub, the unbalanced excitation of the mot