US-12618415-B1 - Fan bearing anti-slip fixing structure with bushing

US12618415B1US 12618415 B1US12618415 B1US 12618415B1US-12618415-B1

Abstract

A fan bearing anti-slip fixing structure with a bushing comprises a fan frame, a shaft, two bearings, two bushings and a first spring. The fan frame has a base with a bearing tube protruding therefrom. The shaft is disposed in the bearing tube. The two bearings are respectively installed in the bearing tube and disposed on the shaft, and respectively include an inner ring fitted to the shaft, and an outer ring fitted to the bearing tube. The two bushings and the first spring are disposed on the shaft and located between the inner rings of the two bearings. The two bushings respectively abut the inner rings of the two bearings, and the first spring is located between the two bushings, and an axial elastic supporting force is generated between the two inner rings via the two bushings.

Inventors

Jing-Ping Huang
Feng Liu
Zuo Zou
Sung-wei Sun

Assignees

ASIA VITAL COMPONENTS CO., LTD.

Dates

Publication Date: 20260505
Application Date: 20250407
Priority Date: 20250214

Claims (5)

1 . A fan bearing anti-slip fixing structure with a bushing, comprising: a fan frame having a base with a bearing tube disposed on the base; a shaft having a connecting end connected to a fan impeller and a free end extending into the bearing tube; a first bearing and a second bearing located in the bearing tube and disposed on the shaft, each of the first bearing and the second bearing including an inner ring and an outer ring and a plurality of rolling members disposed between the inner ring and the outer ring, the outer ring fitted to the bearing tube, and the inner ring fitted to the shaft; a first bushing and a second bushing respectively sleeved on the shaft and located between the inner rings of the first bearing and the second bearing, the first bushing abutting against the inner ring of the first bearing from below, and the second bushing abutting against the inner ring of the second bearing from above; a first spring sleeved on the shaft and located between the first bushing and the second bushing, two ends of the first spring respectively abutting against the first bushing and the second bushing to generate an axial elastic supporting force between the inner rings of the first bearing and the second bearing through the first bushing and the second bushing, thereby the inner rings firmly fixed at a predetermined position through the first bushing and the second bushing to restrict radial relative sliding between the inner rings and the shaft during high-speed operation of the fan.
2 . The fan bearing anti-slip fixing structure with a bushing of claim 1 , wherein the bearing tube has an upper abutment portion and a lower abutment portion, and the first bearing and the second bearing are respectively disposed on the upper abutment portion and the lower abutment portion.
3 . The fan bearing fixing anti-slip structure with a bushing of claim 2 , wherein a second spring is disposed between the outer ring of the second bearing and the lower abutment portion, and one end of the second spring abuts the lower abutment portion and the other end abuts the outer ring of the second bearing.
4 . The fan bearing anti-slip fixing structure with a bushing of claim 3 , wherein the shaft has a neck portion adjacent to the free end, and the neck portion is retained by a retaining ring, and the retaining ring abuts against the inner ring of the second bearing from the other side of the second bearing.
5 . The fan bearing anti-slip fixing structure with a bushing of claim 2 , wherein the outer ring of the first bearing abuts against the upper abutment portion.

Description

This application claims the priority benefit of Taiwan patent application number 114105604 filed on Feb. 14, 2025, the disclosure of which is hereby incorporated by reference in its entirety. FIELD OF THE INVENTION The present invention relates to a bearing fixing structure, and more particularly to a fan bearing anti-slip fixing structure with a bushing. BACKGROUND OF THE INVENTION As shown in FIG. 1, the fan bearing structure includes a fan impeller 11, a base bracket 12, two bearings 13, 14, and upper and lower springs 151, 152. The fan impeller 11 is provided with a rotating shaft 111, and the base bracket 12 is provided with a bearing tube 121. The two bearings 13 and 14 are respectively installed in the bearing tube 121. The rotating shaft 111 is fitted with the two bearings 13 and 14. A spacer 122 is provided in the bearing tube 121, and the two bearings 13 and 14 are distributed above and below the spacer 122. The upper and lower springs 151 and 152 are respectively arranged between the spacer 122 and the two bearings 13 and 14 to apply pressure to the outer rings of the bearings 13 and 14, ensuring that the outer ring raceways are stable and stress is distributed evenly during operation. This double-spring design enables the balls in the bearings 13 and 14 to run smoothly, reducing friction noise during low-speed operation of the fan. Meanwhile, during installation and transportation, the springs 151 and 152 provide effective buffering protection for the bearings 13 and 14, reducing damage caused by external impact. However, this structure primarily focuses on the stability of the outer rings of the bearings 13 and 14 and fails to fully address the problem of radial slipping between the inner rings of the bearings and the rotating shaft 111 during high-speed operation. Consequently, under high-speed conditions, there remains a risk of early bearing failure due to radial slipping. Furthermore, the bearing assembly in current fans may adopt the following two methods: 1. Clearance fit assembly: This method employs a clearance fit between the inner ring of the bearing and the rotating shaft, as well as between the outer ring of the bearing and the bearing tube. This assembly process is simple, offering high efficiency and low cost. However, the clearance fit between the inner ring and the rotating shaft, and between the outer ring and the bearing tube, allows for movement. As fan speed increases, the centrifugal force generated by the high-speed operation of the impeller causes insufficient friction to prevent radial slipping. Over prolonged operation, the bearings are prone to wear and failure, thus shortening the fan's service life.2. Interference fit and glue fixation: In this method, an interference fit is applied between the inner ring of the bearing and the rotating shaft, while the outer ring and the bearing tube are secured with glue. However, this assembly process is complex, requiring precise size control and accurate glue application, resulting in low assembly efficiency and significantly higher manufacturing costs. Additionally, when the fan is subjected to external impact, micro cracks are likely to form at the glue joints, causing the preload within the bearing to be lost. Consequently, the balls cannot maintain their position on the predetermined raceways of the inner and outer rings, leading to micro-motion wear and eventual early bearing failure. Therefore, the above two assembly methods exhibit clear deficiencies with regard to high-speed operation stability and cost control: (1) Bearings assembled with clearance fit cannot effectively resist radial slipping during high-speed operation. (2) Bearings assembled with interference fit and glue fixation incur high assembly costs and remain susceptible to failure under external forces. As a result, existing technologies struggle to simultaneously satisfy the requirements of fan stability during high-speed operation, simple assembly, and cost efficiency. Thus, addressing the aforementioned conventional problems and deficiencies is a key focus for the inventor of the present application and related manufacturers in this industry. SUMMARY OF THE INVENTION An object of the present invention is to provide a fan bearing anti-slip fixing structure with a bushing that addresses the aforementioned issues. The fan bearing anti-slip fixing structure with a bushing of the present invention includes a fan frame, a shaft, a first bearing, a second bearing, a first bushing, a second bushing, and a first spring. The fan frame has a base, with a protruding bearing tube disposed on the base. The shaft has a connecting end attached to a fan impeller and a free end extending into the bearing tube. The first bearing and the second bearing are located within the bearing tube and are disposed on the shaft to support the rotation of the fan impeller. Each of the first bearing and the second bearing includes an inner ring fitted to the shaft and an outer ring fitte