Bearing assembly for brushless air duct motor

Abstract

The utility model relates to the technical field of brushless motors, in particular to a bearing assembly for a brushless air duct motor, which comprises a motor shaft and a pair of bearings, the bearings are sleeved on the motor shaft according to a preset interval and are arranged in a casing, and a fit clearance is reserved between the inner wall of the inner ring of each bearing and the outer wall of the motor shaft. Pre-tightening force is applied to the outer wall of the bearing outer ring, and the bearing outer ring is fixed with the shell; a line groove is arranged on the shaft body surface of the motor shaft corresponding to the installation bearing, and an adhesive is filled between the line groove and the inner wall surface of the bearing inner ring. The high-precision and high-bearing double-bearing motor comprises the high-precision and high-bearing double bearings and the motor shaft with the surface provided with the grain grooves, the grain grooves are used for hiding glue and bonding the bearings, the connection fastening force between the bearings and the shaft is ensured, the connection fastening force is enhanced by 1-2 times compared with the traditional optical shaft connection, the fit clearance between the bearings and the motor shaft is controlled to be 0-0.003 mm, and the service life of the motor is prolonged. The concentricity problem of the two bearings is solved, high-frequency sound and abnormal sound are reduced, and the yield of the bearing assembly is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of brushless motors, in particular to a bearing assembly for a brushless blower motor. Background Art

[0002] Brushless motor is a new type of motor that has emerged with the development of permanent magnet rare earth materials. It is a unified body consisting of a permanent magnet brushless motor body, an electronic commutator and a speed control device. Brushless motors have no brushes, which reduces friction during operation, runs smoothly, reduces noise, and provides support for stable motor operation. In addition, due to the lack of brushes, the motor wear is mainly on the bearings.

[0003] In the prior art, brushless high-speed blower motors mostly use spring-assembled bearings or spring-free integrated assembled bearings; in working scenarios, the defects are:

[0004] (1) The motor shaft adopts an optical shaft structure, and the inner hole of the bearing is connected to the optical shaft, which has poor fastening force. Even if glue is hidden between the optical shaft and the inner hole of the bearing, it cannot meet the fastening requirements. Alternatively, an annular groove is opened on the outer wall of the optical shaft and filled with glue, but there are still fastening defects.

[0005] (2) Refer to the attached Figure 1 As shown, for spring-assembled bearings, the two ends of the spring are used to abut against the outer ring of the bearing. The spring is used to provide preload to the bearing, reduce the axial clearance of the bearing, and compensate for the length change error after the motor heats up, thereby improving the rigidity of the bearing operation and reducing the noise of the bearing; however, in the installation scenario, the spring itself has a large height difference at both ends and a large sag of the entire spring, which will produce abnormal noise during high-speed operation of the motor. For spring-free integrated assembly, although the spring between the bearings is eliminated to reduce the impact of abnormal noise generated by the spring, there is no preload between the bearings, and then when the motor is running, there is a large high-frequency sound and abnormal noise, the bearing is easily worn, and the proportion of defective bearing components is high.

[0006] Therefore, the utility model provides a bearing assembly for a brushless blower motor to solve the problems existing in the prior art. Utility Model Content

[0007] The utility model aims to provide a bearing assembly for a brushless blower motor to solve the technical problems in the prior art that the bearing assembly has poor fastening force and produces large high-frequency sound and abnormal sound when the motor is running.

[0008] The technical solution of the utility model is: a bearing assembly for a brushless blower motor, comprising a motor shaft and a pair of bearings, wherein the pair of bearings are sleeved on the motor shaft at a preset distance and installed in a housing, wherein the bearings comprise a bearing inner ring and a bearing outer ring, wherein a matching clearance exists between the inner wall of the bearing inner ring and the outer wall of the motor shaft, and the outer wall of the bearing outer ring is fixed to the housing by a pre-tightening force;

[0009] A textured groove is arranged on the shaft surface of the motor shaft corresponding to the bearing installation, and an adhesive for improving the installation fastening force of the bearing inner ring is filled between the textured groove and the inner wall surface of the bearing inner ring.

[0010] Preferably, the motor shaft is arranged with equal diameters along the axial direction, and the texture grooves are formed at least on the outer wall surface of the motor shaft for bearing installation.

[0011] Preferably, the pattern grooves are knurled grooves and are formed on the entire outer wall surface of the motor shaft, the knurling depth is set to 0.03-0.07 mm, and the pitch is set to 0.8-1.2 mm.

[0012] Preferably, the knurling depth of the knurling groove is set to 0.05 mm, and the pitch is set to 1 mm.

[0013] Preferably, the fitting clearance between the outer wall of the motor shaft and the inner wall of the bearing inner ring is set to 0-0.003 mm.

[0014] Preferably, a pair of the bearings adopts a deep groove ball bearing series with a precision grade of P5.

[0015] Preferably, the adhesive is a retaining glue.

[0016] Preferably, the coating range of the adhesive along the axial direction of the motor shaft is not less than the axial width of the bearing.

[0017] Compared with the prior art, the advantages of the utility model are:

[0018] (1) The utility model includes a high-precision and high-load double bearing, and a motor shaft with grooves on the surface. The grooves contain glue to bond the bearings, thereby ensuring the connection and tightening force between the bearings and the motor shaft. The connection and tightening force is enhanced by 1-2 times compared with the traditional optical shaft connection.

[0019] (2) Control the clearance between the bearing and the motor shaft to 0-0.003 mm to ensure the concentricity of the two bearings on the shaft, reduce high-frequency sound and abnormal sound, and improve the yield rate of the bearing assembly.

[0020] (3) When the bearing assembly and the housing are assembled, it is achieved through the use of a pressure-maintaining tool with elastic force. The flattened end surface of the tool can apply a preload force to the outer ring of the bearing, so that the outer ring of the bearing and the housing are fixed, and the two bearings can run in a state of good concentricity. Compared with the traditional structure, the spring structure between the two bearings can be omitted; for the entire bearing assembly, the problem of cost control can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0022] Figure 1 A schematic diagram of a bearing assembly with a spring provided by the utility model;

[0023] Figure 2 It is a schematic diagram of the bearing assembly of the utility model;

[0024] Among them: 1. Motor shaft; 2. Bearing; 3. Adhesive; 10. Texture groove. DETAILED DESCRIPTION

[0025] The following is a further detailed description of the present invention in conjunction with specific embodiments:

[0026] like Figure 2 As shown, a bearing assembly for a brushless blower motor includes a motor shaft 1 and a pair of bearings 2. The motor shaft 1 is arranged with equal diameters along the axial direction, and the pair of bearings 2 are sleeved on the motor shaft 1 at a preset distance and installed in a casing.

[0027] Bearing 2 includes a bearing inner ring and a bearing outer ring. Bearing 2 adopts a deep groove ball bearing series, a high-precision bearing with an accuracy grade of P5. If the bearing model is 693 bearing, the size is 3 mm*8 mm*4 mm, with a large load capacity and more stable at high speed operation.

[0028] First, regarding the connection of the bearing outer ring:

[0029] The outer wall of the outer ring of the bearing is preloaded and fixed to the housing. In this embodiment, a pressure-maintaining fixture with elastic force and a very flat fixture end surface is used to apply preload to the outer ring of the bearing and fix it to the housing, so that the two bearings can operate in a state of good concentricity. Figure 1 The traditional structure shown in the figure can omit the spring structure between the two bearings; for the entire bearing assembly, the cost control problem can be achieved.

[0030] Second, regarding the connection of the inner ring of the bearing:

[0031] There is a fitting clearance between the inner wall of the bearing inner ring and the outer wall of the motor shaft 1. By adjusting the fitting clearance between the motor shaft 1 and the inner surface of the bearing inner ring to 0-0.003 mm, the concentricity of the motor shaft and the iron core is improved, and the non-concentricity problem of the motor rotor during operation is reduced.

[0032] A textured groove 10 is provided on the shaft surface of the motor shaft 1 corresponding to the shaft surface where the bearing 2 is installed, and an adhesive 3 for improving the installation fastening force of the bearing inner ring is filled between the textured groove 10 and the inner wall surface of the bearing inner ring.

[0033] Among them, the adhesive 3 uses a retaining glue, such as model 638 anaerobic glue, which has high strength, a maximum radial gap of 0.381 mm, a fast curing speed, and a strong bond. Compared with the optical axis, the motor shaft 1 with a groove on the surface to hold the glue has a higher fastening force with the inner hole of the bearing 2, which is one to two times stronger than using a simple optical axis.

[0034] The pattern groove 10 can be a newly opened groove or a knurled groove formed on the shaft body when the motor shaft is produced. The knurling depth is set to 0.03-0.07 mm and the pitch is set to 1 mm. In this embodiment, the knurling depth of the knurled groove is set to 0.05 mm and the pitch is set to 1 mm.

[0035] The adhesive 3 is evenly distributed to ensure a strong fastening force between the shaft and the bearing. When the adhesive 3 is applied, the coating range of the adhesive 3 along the axial direction of the motor shaft 1 is not less than the axial width of the bearing 2, thereby ensuring that the adhesive 3 can be fully filled between the knurl groove and the fitting clearance.

[0036] Refer to the attached Figure 2 , compared with the attached Figure 1 A schematic diagram of a spring bearing assembly is provided in the figure. An embodiment of the utility model provides a bearing assembly without a spring connection, including a high-precision and high-load-bearing double bearing, and a motor shaft with a grooved surface, which has a simple structure and low cost.

[0037] Keep the clearance between the bearing and the motor shaft at 0-0.003 mm to ensure the concentricity of the two bearings on the shaft.

[0038] By setting grooves on the surface of the motor shaft to hide glue and bond the bearings, the tightening force between the shaft and the inner hole of the bearing is ensured, high-frequency sound and abnormal sound are reduced, and the yield rate of the bearing assembly is improved.

[0039] In addition, when the bearing assembly and the housing are assembled, this is achieved through the use of an elastic pressure-maintaining tooling. The flattened end surface of the tooling can apply a preload to the outer ring of the bearing, fixing the bearing and the housing. The two bearings can operate in a good concentricity state, ensuring that the two bearings have a steady preload when running at high speed, which is more stable.

[0040] The above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with this technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. For those skilled in the art, it is obvious that the utility model is not limited to the details of the above exemplary embodiments, and the utility model can be implemented in other specific forms without departing from the spirit or basic features of the utility model. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the utility model is limited by the attached claims rather than the above description, so it is intended to include all changes within the meaning and scope of the equivalent elements of the claims in the utility model.

Claims

1. A bearing assembly for a brushless blower motor, comprising a motor shaft (1) and a pair of bearings (2), wherein the pair of bearings (2) are sleeved on the motor shaft (1) at a preset distance and installed in a housing, characterized in that: The bearing (2) comprises a bearing inner ring and a bearing outer ring, a fitting clearance exists between the inner wall of the bearing inner ring and the outer wall of the motor shaft (1), and a pre-tightening force is applied to the outer wall of the bearing outer ring to fix it to the housing; wherein the fitting clearance between the outer wall of the motor shaft (1) and the inner wall of the bearing inner ring is set to 0 to 0.003 mm; A grooved groove (10) is provided on the shaft surface of the motor shaft (1) corresponding to the bearing (2) to be installed, and an adhesive (3) for improving the installation fastening force of the bearing inner ring is filled between the grooved groove (10) and the inner wall surface of the bearing inner ring.

2. A bearing assembly for a brushless blower motor according to claim 1, characterized in that: The motor shaft (1) is arranged with equal diameters along the axial direction, and the texture groove (10) is formed at least on the outer wall surface of the motor shaft (1) for mounting the bearing (2).

3. A bearing assembly for a brushless blower motor according to claim 2, characterized in that: The pattern groove (10) is a knurled groove and is formed on the entire outer wall surface of the motor shaft (1). The knurling depth is set to 0.03-0.07 mm, and the pitch is set to 0.8-1.2 mm.

4. A bearing assembly for a brushless fan motor according to claim 3, characterized in that: The knurling depth of the knurling groove is set to 0.05 mm, and the pitch is set to 1 mm.

5. A bearing assembly for a brushless blower motor according to claim 2, characterized in that: The pair of bearings (2) are deep groove ball bearings of precision grade P5.

6. A bearing assembly for a brushless blower motor according to claim 1, characterized in that: The adhesive (3) is a retaining glue.

7. A bearing assembly for a brushless blower motor according to claim 1, characterized in that: The coating range of the adhesive (3) along the axial direction of the motor shaft (1) is not less than the width of the bearing (2) along the axial direction.

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