Bearing pre-pressing structure of heat dissipation fan

Abstract

This invention discloses a bearing preload structure for a cooling fan, belonging to the field of cooling fan technology. The bearing preload structure includes: an upper bearing, a lower bearing, a middle spring, and an outer ring spring. The upper bearing is a double-raceway bearing. The inner rings of both the upper and lower bearings mate with the shaft of the cooling fan, and the outer rings of both bearings mate with the bearing housing of the cooling fan. The middle spring is positioned between the inner rings of the upper and lower bearings, providing axial preload to the inner rings. The outer ring spring is positioned between the outer ring of the upper bearing and the bearing housing, providing axial preload to the outer ring of the upper bearing. This invention reduces unilateral wear on the upper bearing raceway through the cooperation of the double-raceway upper bearing, the middle spring, and the outer ring spring, solving the problem of low bearing life in existing technologies.

Description

Technical Field

[0001] This invention belongs to the field of cooling fan technology, specifically a bearing preload structure for a cooling fan. Background Technology

[0002] Traditional cooling fans use, for example Figure 1 The upper and lower double single raceway bearings with upper spring 203 preload structure shown are prone to problems such as excessive preload of the upper spring on the bearing at high speeds >20000 RPM, which leads to increased wear on one side of the upper bearing raceway, increased temperature, rapid grease deterioration, and short bearing service life.

[0003] The existing improvement scheme only optimizes the spring stiffness and does not solve the fundamental problem of uneven load distribution, so the problem of short bearing life still exists. Summary of the Invention

[0004] Purpose of the invention: To provide a bearing preload structure for a cooling fan, which reduces unilateral wear on the upper bearing raceway through the cooperation of a double-raceway upper bearing, a middle spring, and an outer ring spring, thus solving the problem of low bearing life in existing technologies.

[0005] The technical solution of the present invention is as follows: a bearing preload structure for a cooling fan includes an upper bearing, a lower bearing, a middle spring, and an outer ring spring.

[0006] The upper bearing is a double raceway bearing. The inner rings of the upper and lower bearings are fitted with the shaft of the cooling fan, and the outer rings of the upper and lower bearings are fitted with the bearing housing of the cooling fan.

[0007] The middle spring is disposed between the inner rings of the upper bearing and the lower bearing, and the middle spring is used to provide axial preload to the inner rings of the upper bearing and the lower bearing.

[0008] The outer ring spring is disposed between the outer ring of the upper bearing and the bearing housing, and the outer ring spring is used to provide axial preload to the outer ring of the upper bearing.

[0009] In a further embodiment, the axial preload of the middle spring is greater than the axial preload of the outer spring, making the inner ring of the upper bearing more resistant to displacement than the outer ring, thereby further reducing the displacement difference between the inner and outer rings when the upper bearing swings.

[0010] In a further embodiment, the axial preload of the spring is 950-1100 gf.

[0011] The axial preload of the outer ring spring is 250-350gf. A suitable preload can ensure the stability of the bearing while reducing the displacement difference between the inner and outer rings when the upper bearing swings.

[0012] In a further embodiment, the upper bearing is a bearing with dimensions of φ8.0*φ3.0*8.0.

[0013] In a further embodiment, the lower bearing is a ball bearing.

[0014] In a further embodiment, the spring is a straight column spring.

[0015] In a further embodiment, the outer spring is a ring-shaped wave spring.

[0016] In a further embodiment, the dual-race bearing comprises two independent ball tracks.

[0017] In a further embodiment, the lower bearing is a single-raceway bearing, which ensures radial rigidity.

[0018] The assembly method for the bearing preload structure used in a cooling fan includes: first, mounting the lower bearing to the shaft, and then mounting the lower bearing to the bearing housing.

[0019] Then, the middle spring and the outer spring are installed in the bearing housing, and the middle spring and the outer spring are sleeved on the rotating shaft, so that the middle spring mates with the inner ring of the lower bearing.

[0020] Then, install the upper bearing in the bearing housing, install the upper bearing on the rotating shaft, mate the inner ring of the upper bearing with the middle spring, and mate the outer ring of the upper bearing with the outer ring spring.

[0021] The beneficial effects of this invention are: This application provides axial preload to the inner rings of the upper and lower bearings through the middle spring, so that the preload of the middle spring is evenly applied to the inner rings of the two bearings. Compared with the prior art where the upper spring preloads the upper bearing and the preload is transmitted downward from the upper bearing, this reduces the probability of the upper spring over-preloading the upper bearing and improves the service life of the upper bearing.

[0022] By using a double-raceway bearing as the upper bearing, the double raceways bear the force during bearing oscillation, thus dispersing the force and improving the uniformity of load distribution on the upper bearing. Compared with the single-raceway technology in the past, this reduces wear on one side of the raceway and further improves the service life of the upper bearing.

[0023] By using the middle spring and outer spring to provide preload to the inner and outer rings of the upper bearing respectively, the inner and outer rings of the upper bearing float axially, reducing the displacement difference between the inner and outer rings when the upper bearing swings, and further improving the service life of the upper bearing. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the bearing preload structure of a current technology cooling fan.

[0025] Figure 2This is a schematic diagram of the bearing preload structure of the cooling fan of the present invention.

[0026] Figure 3 This is a schematic diagram comparing the service life of the upper bearing under continuous testing at different ambient temperatures with a fan speed of 26000 RPM. XR = traditional upper spring structure, XB = optimized spring stiffness of traditional spring structure, and XF = design of this invention.

[0027] The reference numerals in the figure are: upper bearing 101, lower bearing 102, middle spring 201, outer spring 202, and upper spring 203. Detailed Implementation

[0028] In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without one or more of these details. In other instances, certain technical features well-known in the art have not been described in order to avoid obscuring the invention.

[0029] This invention discloses a bearing preload structure for a cooling fan, which reduces unilateral wear on the raceway of the upper bearing 101 through the cooperation of the double-raceway upper bearing 101, the middle spring 201 and the outer ring spring 202. It is especially suitable for high-speed cooling fans with a speed >20000 RPM and solves the problem of low service life of bearings in the prior art.

[0030] like Figure 2 The bearing preload structure of the cooling fan shown includes: an upper bearing 101, a lower bearing 102, a middle spring 201, and an outer ring spring 202.

[0031] The upper bearing 101, the lower bearing 102, the middle spring 201 and the outer ring spring 202 are disposed in the bearing housing of the cooling fan, and the bearing housing is disposed in the stator.

[0032] The upper bearing 101 is a double-race bearing. The inner rings of the upper bearing 101 and the lower bearing 102 mate with the shaft of the cooling fan, and the outer rings of the upper bearing 101 and the lower bearing 102 mate with the bearing housing of the cooling fan. Figure 2 The bearing housing shown is installed in the middle of the stator, the shaft passes through the bearing housing, and one end of the shaft is connected to the fan blade.

[0033] The middle spring 201 is disposed between the inner rings of the upper bearing 101 and the lower bearing 102, and the middle spring 201 is used to provide axial preload to the inner rings of the upper bearing 101 and the lower bearing 102.

[0034] The outer ring spring 202 is disposed between the outer ring of the upper bearing 101 and the bearing housing, and the outer ring spring 202 is used to provide axial preload to the outer ring of the upper bearing 101.

[0035] In this embodiment, the axial preload of the middle spring 201 is greater than the axial preload of the outer spring 202.

[0036] In this embodiment, the axial preload of the middle spring 201 is 950-1100 gf, and in a preferred embodiment, the axial preload of the middle spring 201 is 1000 gf.

[0037] The axial preload of the outer coil spring 202 is 250-350 gf. In a preferred embodiment, the axial preload of the outer coil spring 202 is 300 gf.

[0038] In this embodiment, the upper bearing 101 is a bearing with dimensions of φ8.0*φ3.0*8.0.

[0039] In this embodiment, the lower bearing 102 is a ball bearing.

[0040] In this embodiment, the middle spring 201 is a straight column spring.

[0041] In this embodiment, the outer spring 202 is a ring wave spring.

[0042] In this embodiment, the double raceway bearing is a double raceway ball bearing that includes two independent ball tracks.

[0043] In this embodiment, the lower bearing 102 is a single-race bearing.

[0044] The assembly method includes: first, mounting the lower bearing 102 onto the rotating shaft, and then mounting the lower bearing 102 onto the bearing housing.

[0045] Then, the middle spring 201 and the outer spring 202 are installed in the bearing housing, and the middle spring 201 and the outer spring 202 are sleeved on the rotating shaft, so that the middle spring 201 mates with the inner ring of the lower bearing 102.

[0046] Then, the upper bearing 101 is installed in the bearing housing, the upper bearing 101 is installed on the rotating shaft, the inner ring of the upper bearing 101 is engaged with the middle spring 201, the outer ring of the upper bearing 101 is engaged with the outer ring spring 202, and the preload of the middle spring 201 is transmitted from the upper bearing 101 to the lower bearing 102.

[0047] As described above, although the invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A bearing preload structure for a cooling fan, characterized in that, include: Upper bearing, lower bearing, middle spring, and outer spring; The upper bearing is a double raceway bearing. The inner rings of the upper and lower bearings are fitted with the shaft of the cooling fan, and the outer rings of the upper and lower bearings are fitted with the bearing housing of the cooling fan. The middle spring is disposed between the inner rings of the upper bearing and the lower bearing, and the middle spring is used to provide axial preload to the inner rings of the upper bearing and the lower bearing. The outer ring spring is disposed between the outer ring of the upper bearing and the bearing housing, and the outer ring spring is used to provide axial preload to the outer ring of the upper bearing.

2. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The axial preload of the inner spring is greater than the axial preload of the outer spring.

3. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The axial preload of the spring is 950-1100 gf; The axial preload of the outer spring is 250-350 gf.

4. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The upper bearing is a φ8.0*φ3.0*8.0 bearing.

5. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The lower bearing is a ball bearing.

6. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The spring mentioned is a straight column spring.

7. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The outer spring is a ring-shaped wave spring.

8. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The dual-race bearing comprises two independent ball tracks.

9. The bearing preload structure of a cooling fan according to claim 1, characterized in that, The lower bearing is a single-race bearing.

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