Brushless direct current motor capable of reducing noise

Abstract

The utility model relates to the technical field of motors, and discloses a noise-reducing brushless direct current motor, which comprises a motor shell, a channel is arranged in the motor shell, and a bearing and a bearing pre-compression assembly are arranged in the channel; the bearing pre-pressure assembly comprises a first stress block, a second stress block and a wave-shaped elastic pad. The first stress block and the second stress block are in axial positioning fit through a first positioning piece, and the first stress block and the second stress block are in radial positioning fit through a second positioning piece. A wave-shaped spring washer is arranged between the first stress block and the second stress block; the rotating shaft penetrates through the first stress block, the second stress block and the wave-shaped spring washer. According to the utility model, the bearing pre-compression assembly is tightly attached to the bearing and is not easy to deflect due to stress, so that the noise caused by non-uniform stress during axial installation of the motor can be reduced; meanwhile, the bearing pressure assembly can vertically contact with the bearing end face, the bearing stress area is effectively increased, and noise caused by axial installation errors of the motor can be reduced; therefore, the failure rate of products is reduced, and the service life of the products is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to motor technical field, especially a kind of brushless DC motor of reducing noise. BACKGROUND

[0002] Small or micro motor, for example, a high-speed permanent magnet brushless DC motor has a series of advantages such as large power density, small geometric size, fast dynamic response and high operating efficiency, which has broad application prospects in high-speed running occasions, such as high-speed permanent magnet brushless motor used in hair dryer.

[0003] The large wind force low-noise side-inlet hair dryer disclosed in the utility model has the advantages that the air inlet is formed in the left and right outer shells, the air inlet cover and the air inlet iron net are arranged in the air inlet, the inner air duct is arranged in the shell body, the axial direction of the inner air duct is perpendicular to the axial directions of the two air inlets, the air inlet end of the inner air duct extends to the rear side of the shell body to form a motor support, the brushless DC motor assembly with a fan is arranged in the motor support, and the brushless DC motor assembly is fastened to the motor support by the fixing cover.

[0004] Based on the above technical features, the problem is that the existing brushless DC motor needs to apply pre-tightening force between the bearings to eliminate the installation gap between the inner and outer rings of the bearings. The existing brushless DC motor usually designs a compression spring structure to apply pre-tightening force between the bearings. Due to the bending of the steel wire, the perpendicularity of the two end faces to the axis is usually inclined, thereby causing the bearing to be skewed under the spring force after the bearing and the spring are installed, and causing problems such as motor noise.

[0005] Therefore, it is necessary to solve the above problems by a brushless DC motor for reducing noise. UTILITY MODEL CONTENTS

[0006] The utility model aims at providing a brushless DC motor for reducing noise to solve the problems in the above background.

[0007] In order to achieve the above object, the utility model provides the following technical scheme: a kind of brushless direct current motor of reducing noise, including motor shell, channel is arranged in the motor shell along the axial direction, bearing and bearing pre-pressure component are placed in the channel;Internal cavity is arranged in the motor shell along the axial direction, stator assembly is installed in the internal cavity, and rotor assembly is coaxially inserted in stator assembly;Rotor assembly includes shaft, and magnetic ring is fixedly sleeved on the shaft;Bearing includes first bearing and second bearing, and bearing pre-pressure component is installed between first bearing and second bearing;The shaft passes through bearing pre-pressure component, first bearing and second bearing, while fixedly sleeving fan blade on the shaft;Bearing pre-pressure component includes first force block, second force block and wave-shaped elastic pad;The first force block and the second force block are axially positioned by first positioning member, and the first force block and the second force block are radially positioned by second positioning member;Wave-shaped elastic pad is arranged between the first force block and the second force block;The shaft passes through first force block, second force block and wave-shaped elastic pad.

[0008] Preferably, the wave-shaped elastic pad is annular and has a wave structure along a circumferential direction; the first force block and the second force block are both cylindrical structures, and the wave-shaped elastic pad is coaxially abutted with the first force block and the second force block; the first force block is abutted with the first bearing, and the second force block is abutted with the second bearing.

[0009] Preferably, the first positioning member includes a boss; the boss is annular and located between the first force block and the second force block; the boss is coaxially fixedly connected with the first force block; a ring groove matched with the boss is formed on the second force block, and the wave-shaped elastic pad is located in the ring groove; the boss is coaxially inserted into the ring groove and abutted with the wave-shaped elastic pad.

[0010] Preferably, the second positioning member includes an L-shaped flange and an L-shaped groove; the L-shaped flange is fixed on the second force block, and the L-shaped groove is formed on the outer wall of the first force block; the L-shaped flange and the L-shaped groove are matched and buckled.

[0011] Preferably, both axial ends of the first force block are provided with notches; the notches are communicated with the L-shaped groove and jointly form a curved groove with the L-shaped groove.

[0012] Preferably, a glue storage groove is formed on the outer wall of the second force block and penetrates the second force block along the axial direction of the second force block.

[0013] The technical effect and advantages of the utility model are: the bearing pre-pressure assembly of the utility model is closely attached to the bearing, is not easy to be forced to deflect, is favorable for reducing the noise caused by uneven force of motor axial installation; simultaneously the bearing pressure assembly can vertically contact the bearing end face, effectively improves the bearing force area, is favorable for the motor to reduce the noise caused by axial installation error; thereby reduces the failure rate of product, promotes the service life of product. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 It is the three-dimensional front view schematic diagram of the utility model;

[0015] Figure 2 It is the B-B half cut schematic diagram of the utility model; Figure 1

[0016] Figure 3 It is the three-dimensional explosion schematic diagram of the utility model; Figure 1

[0017] Figure 4 It is the passage schematic diagram of the utility model;

[0018] Figure 5 It is the internal cavity schematic diagram of the utility model;

[0019] Figure 6 It is the bearing pre-pressure assembly schematic diagram of the utility model;

[0020] Figure 7 It is the bearing pre-pressure assembly axial schematic diagram of the utility model;

[0021] Figure 8 It is the D-D half cut schematic diagram of the utility model; Figure 7

[0022] In the drawing: 1, joint; 2, circuit board; 3, coil winding; 4, stator core; 5, magnetic ring; 6, rotating shaft; 7, first bearing; 8-1, first force block; 8-1-1, L-shaped recess; 8-1-2, boss; 8-2, second force block; 8-2-1, L-shaped flange; 8-2-2, glue retention groove; 9, second bearing; 10, motor housing; 10-1, passage; 10-2, internal cavity; 11, fan blade. DETAILED DESCRIPTION

[0023] The technical scheme in the embodiments of the utility model will be apparently and completely described in combination with the drawings in the embodiments of the utility model, and obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments, and all other embodiments obtained by the person skilled in the art without creative labor based on the embodiments in the utility model belong to the protection scope of the utility model. ​​​

[0024] The utility model provides a reduce noise brushless DC motor as Figures 1 to 8 As shown in a kind of reducing noise brushless DC motor, including motor casing 10, channel 10-1 is provided in motor casing 10 along the axial direction, bearing and bearing pre-pressure assembly are placed in channel 10-1.

[0025] Internal cavity 10-2 is provided in motor casing 10 along the axial direction, stator assembly is installed in internal cavity 10-2, and the coaxial rotor assembly is inserted in stator assembly.

[0026] Stator assembly includes stator core 4 and coil winding 3, and coil winding 3 is wound on stator core 4.Circuit board 2 is electrically connected to coil winding 3, and connector 1 is electrically connected to circuit board 2.Circuit board 2 is fixedly connected to motor casing 10, and connector 1 is fixedly connected to circuit board 2.

[0027] Rotor assembly includes rotating shaft 6, and magnetic ring 5 is fixedly sleeved on rotating shaft 6.Magnetic ring 5 is coaxially rotatably installed in stator assembly.Rotating shaft 6 passes through bearing pre-pressure assembly, first bearing 7 and second bearing 9, and simultaneously fan blade 11 is fixedly sleeved on rotating shaft 6.

[0028] First bearing 7 and second bearing 9 are fixedly sleeved on rotating shaft 6, and rotating shaft 6 is rotatably connected to motor casing 10 by first bearing 7 and second bearing 9.

[0029] Bearing pre-pressure assembly includes first force block 8-1, second force block 8-2 and wave-shaped elastic pad 8-3.

[0030] First force block 8-1 and second force block 8-2 are both cylindrical structure, and are both formed by metal pressure casting.First force block 8-1 and second force block 8-2 are both machined by machine tool, and perpendicularity is within 0.02mm.

[0031] First force block 8-1 and second force block 8-2 are axially positioned by first positioning piece, and first force block 8-1 and second force block 8-2 are radially positioned by second positioning piece.

[0032] First positioning piece includes boss 8-1-2.Boss 8-1-2 is annular, and is located between first force block 8-1 and second force block 8-2.Boss 8-1-2 is coaxially fixedly connected to first force block 8-1, and ring groove matched with boss 8-1-2 is formed in second force block 8-2.Boss 8-1-2 is coaxially inserted into ring groove.

[0033] The wave-shaped elastic pad 8-3 is annular and has a wave structure in the circumferential direction. The wave-shaped elastic pad 8-3 is located in the annular groove, and the boss 8-1-2 and the second stress block 8-2 are coaxially extruded on the wave-shaped elastic pad 8-3. At the same time, the first stress block 8-1 is in abutment with the first bearing 7, and the second stress block 8-2 is in abutment with the second bearing 9.

[0034] The rotating shaft 6 penetrates the first stress block 8-1, the second stress block 8-2, and the wave-shaped elastic pad 8-3.

[0035] The second positioning member includes an L-shaped flange 8-2-1 and an L-shaped groove 8-1-1. The L-shaped flange 8-2-1 is fixed to the second stress block 8-2, and the L-shaped groove 8-1-1 is formed on the outer wall of the first stress block 8-1. The L-shaped flange 8-2-1 and the L-shaped groove 8-1-1 are matched, and the L-shaped flange 8-2-1 and the L-shaped groove 8-1-1 are buckled.

[0036] Both axial ends of the first stress block 8-1 are provided with notches; both notches are in communication with the L-shaped groove 8-1-1, and together with the L-shaped groove 8-1-1, they form a curved groove.

[0037] In the present example, the number of L-shaped flanges 8-2-1 and L-shaped grooves 8-1-1 is preferably two, two L-shaped flanges 8-2-1 are distributed along the circumference of the second stress block 8-2, and two L-shaped grooves 8-1-1 are distributed along the circumference of the first stress block 8-1. Two L-shaped flanges 8-2-1 and two L-shaped grooves 8-1-1 correspond to each other, and each L-shaped flange 8-2-1 is buckled with the corresponding L-shaped groove 8-1-1.

[0038] The outer wall of the second stress block 8-2 is provided with a glue storage groove 8-2-2, which penetrates the second stress block 8-2 in the axial direction of the second stress block 8-2. It is convenient to store excess glue. In the present embodiment, the number of glue storage grooves 8-2-2 is preferably two, and the two glue storage grooves 8-2-2 are distributed along the circumference of the second stress block 8-2.

[0039] Working principle: when assembling the brushless motor, first fix the magnetic ring 5 on the rotating shaft 6, then successively install the first bearing 7, the first force block 8-1, the wave-shaped elastic pad 8-3, the second force block 8-2 and the second bearing 9 on the rotating shaft 6, the order can be adjusted according to the actual installation process. When installing the first force block 8-1, the boss 8-1-2 is located on the side of the first force block 8-1 away from the first bearing 7. Then when installing the wave-shaped elastic pad 8-3, first coaxially slide the wave-shaped elastic pad 8-3 into the ring groove of the second force block 8-2, at this time the wave-shaped elastic pad 8-3 and the second force block 8-2 are clamped due to friction. Then when installing the second force block 8-2, the end of the second force block 8-2 with the L-shaped flange 8-2-1 faces the first force block 8-1. Then align the L-shaped flange 8-2-1 with the corresponding L-shaped groove 8-1-1, then push the second force block 8-2 to make the L-shaped flange 8-2-1 slide from the gap of the first force block 8-1 into the L-shaped groove 8-1-1. Then press the second force block 8-2, when the L-shaped flange 8-2-1 is completely in the L-shaped groove 8-1-1, rotate the second force block 8-2 to make the L-shaped flange 8-2-1 and the L-shaped groove 8-1-1 form a snap fit. In this process, the wave-shaped elastic pad 8-3 is squeezed by the boss 8-1-2 and the second force block 8-2. Thus the installation of the bearing pre-pressure assembly is completed.

[0040] Finally, it should be pointed out that: the above only for preferred embodiments of the present application, and not for limiting the present application, although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features, any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application, should be included in the protection scope of the present application.

Claims

1. A reduced noise brushless DC motor comprising a motor housing (10) characterised in that: The motor housing (10) is provided with a channel (10-1) in the axial direction, the channel (10-1) is provided with a bearing and a bearing pre-pressure assembly; the motor housing (10) is provided with an internal cavity (10-2) in the axial direction, the internal cavity (10-2) is provided with a stator assembly, the stator assembly is coaxially penetrated by a rotor assembly; the rotor assembly comprises a rotating shaft (6), the rotating shaft (6) is provided with a magnetic ring (5); the bearing comprises a first bearing (7) and a second bearing (9), the bearing pre-pressure assembly is arranged between the first bearing (7) and the second bearing (9); the rotating shaft (6) penetrates the bearing pre-pressure assembly, the first bearing (7) and the second bearing (9), and the rotating shaft (6) is provided with a fan blade (11); the bearing pre-pressure assembly comprises a first stress block (8-1), a second stress block (8-2) and a wave-shaped elastic pad (8-3); the first stress block (8-1) and the second stress block (8-2) are axially positioned by a first positioning member, and the first stress block (8-1) and the second stress block (8-2) are radially positioned by a second positioning member; the wave-shaped elastic pad (8-3) is arranged between the first stress block (8-1) and the second stress block (8-2); the rotating shaft (6) penetrates the first stress block (8-1), the second stress block (8-2) and the wave-shaped elastic pad (8-3).

2. A noise-reduced brushless DC motor according to claim 1, characterized in that: The wave-shaped elastic pad (8-3) is annular and has a wave structure in the circumferential direction; the first stress block (8-1) and the second stress block (8-2) are both cylindrical structures, and the wave-shaped elastic pad (8-3) is coaxially abutted with the first stress block (8-1) and the second stress block (8-2); the first stress block (8-1) is abutted with the first bearing (7), and the second stress block (8-2) is abutted with the second bearing (9).

3. A reduced noise brushless DC motor as claimed in claim 2, characterized in that: The first positioning member comprises a boss (8-1-2); the boss (8-1-2) is annular and located between the first stress block (8-1) and the second stress block (8-2); the boss (8-1-2) is coaxially fixedly connected with the first stress block (8-1); the second stress block (8-2) is provided with a ring groove matched with the boss (8-1-2), the wave-shaped elastic pad (8-3) is located in the ring groove, and the boss (8-1-2) is coaxially inserted into the ring groove and abutted with the wave-shaped elastic pad (8-3).

4. The low noise brushless DC motor of claim 2, wherein: The second positioning member comprises an L-shaped flange (8-2-1) and an L-shaped groove (8-1-1); the L-shaped flange (8-2-1) is fixed to the second stress block (8-2), and the L-shaped groove (8-1-1) is formed on the outer wall of the first stress block (8-1); the L-shaped flange (8-2-1) and the L-shaped groove (8-1-1) are matched, and the L-shaped flange (8-2-1) and the L-shaped groove (8-1-1) are buckled.

5. A reduced noise brushless DC motor as claimed in claim 4, characterized in that: Both axial ends of the first stress block (8-1) are provided with notches; both notches are communicated with the L-shaped groove (8-1-1), and the notches and the L-shaped groove (8-1-1) jointly form a curved groove.

6. A reduced noise brushless DC motor as claimed in claim 5, characterized in that: The outer wall of the second stress block (8-2) is provided with a glue storage groove (8-2-2) which penetrates the second stress block (8-2) in the axial direction of the second stress block (8-2).

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