Brushless DC Motor

Abstract

The present invention relates to a brushless DC motor, comprising a rotor core and a plurality of magnets arranged at intervals on the outer circumferential surface of the rotor core along the axial direction of the rotor core; wherein a plurality of rotor false teeth are distributed on the outer circumferential surface of the rotor core, each rotor false tooth is provided with a set of wedge assemblies, and each magnet is arranged between two adjacent sets of wedge assemblies. The brushless DC motor proposed by the present invention has a simple structure, low cost, firm and reliable installation of magnets, and good motor performance.

Description

Technical Field

[0001] The invention relates to the technical field of electrical connection, and in particular to a brushless DC motor. Background Art

[0002] One of the traditional ways to fix and install the magnets on the rotor of an inner rotor brushless DC motor is to use adhesive to directly stick them on the outer surface of the rotor core, so that the magnets are evenly distributed on the outer surface of the rotor core. For inner rotor motors with higher speeds, a rotor steel sleeve or a rotor tie is added to the rotor surface. The defects of this way of fixing and installing the magnets are: this direct adhesive installation method is not conducive to the positioning of the magnets. In addition, the presence of the rotor steel sleeve will increase the loss of the motor, and the process of wrapping the tie on the rotor surface is also very complicated. After wrapping the tie and applying the adhesive, post-processing is required. It is necessary to remove the excess adhesive on the rotor surface, and use a lathe to turn the rotor surface as smooth as possible, and ensure that the air gap between the stator and the rotor is consistent with the designed air gap. In addition, due to the heat generated during the electromechanical energy conversion process and the heat generated during the high-speed operation of the motor, not only the impact resistance of the magnet is reduced, but also the adhesive is ineffective due to heat, and the magnet often falls off.

[0003] Another way to install the magnet on the rotor of the traditional inner rotor brushless DC motor is to install the magnet fixing bracket on the rotor false teeth. Like the first installation method, the magnets are evenly distributed on the outer circle of the rotor core. The difference is that the rotor false teeth are designed between the poles of the rotor core, and the rotor false teeth and the magnet bracket are designed in a concave-convex groove structure, which is convenient for the magnet bracket to be sleeved on the rotor false teeth. After the magnet is inserted between the two magnet brackets, a wedge is inserted to fix the magnet. The defects of this magnet fixing installation method are: too many parts are required, the processing process of the magnet bracket is complicated, and the installation process is many, so for the whole motor, the manufacturing cost is high, time-consuming and labor-intensive.

[0004] In view of the above technical problems, it is necessary to propose a solution with simple structure, low cost, firm and reliable magnetic steel installation and good motor performance. Summary of the invention

[0005] The present invention provides a brushless DC motor, which aims to simplify the structure, reduce the cost, reduce the eddy current loss of the motor and the leakage flux between the magnetic poles, and improve the performance of the motor.

[0006] To achieve the above-mentioned purpose, the present invention is implemented as follows: the present invention provides a brushless DC motor, including a rotor core and a plurality of magnets arranged on the outer circumferential surface of the rotor core at intervals along the axial direction of the rotor core; wherein a plurality of rotor false teeth are distributed on the outer circumferential surface of the rotor core, a set of wedge assemblies is arranged on each rotor false tooth, and each magnet is arranged between two adjacent sets of wedge assemblies.

[0007] A further technical solution of the present invention is that the rotor false tooth is a T-shaped structure with concave sides, and the bottom of the rotor false tooth of the T-shaped structure is fixedly connected to the outer periphery of the rotor core.

[0008] A further technical solution of the present invention is that each set of wedge assemblies includes a first Z-shaped wedge and a second inverted Z-shaped wedge, and the first Z-shaped wedge and the second inverted Z-shaped wedge are respectively clamped on both sides of the rotor false teeth of the T-shaped structure.

[0009] A further technical solution of the present invention is that the cross-section of the magnetic steel is arc-shaped, and step-like structures are arranged at both ends of the arc-shaped magnetic steel. The two adjacent sets of wedge assemblies include a first set of wedge assemblies and a second set of wedge assemblies. The magnetic steel is arranged between the first set of wedge assemblies and the second set of wedge assemblies, and one end of the magnetic steel is clamped on one side of the Z-shaped first wedge in the first set of wedge assemblies, and the other end of the magnetic steel is clamped on one side of the inverted Z-shaped second wedge in the second set of wedge assemblies.

[0010] A further technical solution of the present invention is that the Z-shaped first wedge and the reverse Z-shaped second wedge are respectively bonded to both sides of the rotor false tooth of the T-shaped structure by using adhesive.

[0011] A further technical solution of the present invention is that one end of the magnetic steel is bonded to one side of the Z-shaped first wedge in the first set of wedge assemblies by adhesive, and the other end of the magnetic steel is bonded to one side of the inverted Z-shaped second wedge in the second set of wedge assemblies by adhesive.

[0012] A further technical solution of the present invention is that the outer surfaces of the Z-shaped first wedge and the reverse Z-shaped second wedge are located on the same arc surface as the outer surface of the magnetic steel.

[0013] A further technical solution of the present invention is that the first wedge and the second wedge are both made of non-magnetic materials.

[0014] The beneficial effects of the present invention are as follows: the present invention arranges a plurality of rotor false teeth at intervals along the axial direction of the rotor core on the outer circumferential surface of the rotor core, wherein a set of wedge assemblies is arranged on each rotor false tooth, and magnetic steel is arranged between two adjacent sets of wedge assemblies, thereby simplifying the installation structure of the magnetic steel, reducing costs, and the installation of the magnetic steel is more firm and reliable, and the motor performance is better. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the assembly of a brushless DC motor proposed in a preferred embodiment of the present invention;

[0016] Figure 2It is a schematic diagram of the rotor core structure of a brushless DC motor proposed in a preferred embodiment of the present invention;

[0017] Figure 3 It is a structural schematic diagram of a wedge in a brushless DC motor proposed in a preferred embodiment of the present invention;

[0018] Figure 4 It is a schematic diagram of the magnetic steel structure in the brushless DC motor proposed in the preferred embodiment of the present invention.

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] At present, the method of fixing the magnetic steel on the rotor of the brushless DC motor is to use adhesive to directly stick it on the outer surface of the rotor core or install a magnetic steel fixing bracket on the rotor false teeth, and insert the magnetic steel between two magnetic steel brackets. Among them, the first fixing method not only reduces the impact resistance of the magnetic steel due to the heat generated during the electromechanical energy conversion process and the heat generated during the high-speed operation of the motor when the motor is running, but also makes the adhesive ineffective due to heat, and the magnetic steel often falls off. The second fixing method requires too many parts, the processing process of the magnetic steel bracket is complicated, and the installation process is multi-step, so for the whole motor, the manufacturing cost is high, time-consuming and labor-intensive.

[0022] In view of the above technical problems, the present invention proposes a brushless DC motor with simple structure, low cost, firm and reliable magnetic steel installation and good motor performance.

[0023] The main solution of the present invention is: a plurality of rotor false teeth are arranged at intervals on the outer circumferential surface of the rotor core along the axial direction of the rotor core, wherein a set of wedge assemblies is arranged on each rotor false tooth, and magnetic steel is arranged between two adjacent sets of wedge assemblies, thereby simplifying the installation structure of the magnetic steel, reducing costs, and the installation of the magnetic steel is more firm and reliable, and the motor performance is better.

[0024] Specifically, refer to Figure 1-Figure 4 , Figure 1 It is a schematic diagram of the assembly of a brushless DC motor proposed in a preferred embodiment of the present invention; Figure 2 It is a schematic diagram of the rotor core structure of a brushless DC motor proposed in a preferred embodiment of the present invention; Figure 3 It is a structural schematic diagram of a wedge in a brushless DC motor proposed in a preferred embodiment of the present invention; Figure 4 It is a schematic diagram of the magnetic steel structure in the brushless DC motor proposed in the preferred embodiment of the present invention.

[0025] like Figures 1 to 4 As shown, a preferred embodiment of the present invention provides a brushless DC motor, which includes a rotor core 1 and a plurality of magnets 4 arranged on the outer circumferential surface of the rotor core 1 at intervals along the axial direction of the rotor core 1; wherein, a plurality of rotor false teeth 2 are distributed on the outer circumferential surface of the rotor core 1, a set of wedge assemblies 3 is arranged on each rotor false tooth 2, and each magnet 4 is arranged between two adjacent sets of wedge assemblies 3.

[0026] Therefore, compared with the prior art, not only the installation structure of the magnetic steel 4 is simplified and the cost is reduced, but also the eddy current loss of the motor and the leakage flux between the magnetic poles are reduced, thereby improving the motor performance.

[0027] As an implementation manner, the rotor false tooth 2 is a T-shaped structure with concave sides, and the bottom of the rotor false tooth 2 of the T-shaped structure is fixedly connected to the outer periphery of the rotor core 1.

[0028] As an embodiment, each set of wedge assemblies 3 includes a Z-shaped first wedge 301 and an inverted Z-shaped second wedge 302, and the Z-shaped first wedge 301 and the inverted Z-shaped second wedge 302 are respectively clamped on both sides of the rotor false tooth 2 of the T-shaped structure.

[0029] As an embodiment, the cross-section of the magnetic steel 4 is arc-shaped, and step-like structures are provided at both ends of the arc-shaped magnetic steel 4. The two adjacent sets of wedge assemblies 3 include a first set of wedge assemblies 3 and a second set of wedge assemblies 3. The magnetic steel 4 is arranged between the first set of wedge assemblies 3 and the second set of wedge assemblies 3, and one end of the magnetic steel 4 is clamped on one side of the Z-shaped first wedge 301 in the first set of wedge assemblies 3, and the other end of the magnetic steel 4 is clamped on one side of the inverted Z-shaped second wedge 302 in the second set of wedge assemblies 3.

[0030] As an implementation manner, the Z-shaped first wedge 301 and the reverse Z-shaped second wedge 302 are respectively bonded to the two sides of the T-shaped rotor false tooth 2 by using adhesive.

[0031] As an embodiment, one end of the magnetic steel 4 is bonded to one side of the Z-shaped first wedge 301 in the first set of wedge assemblies 3 by using adhesive, and the other end of the magnetic steel 4 is bonded to one side of the inverted Z-shaped second wedge 302 in the second set of wedge assemblies 3 by using adhesive.

[0032] As an implementation manner, the outer surfaces of the Z-shaped first wedge 301 and the reverse Z-shaped second wedge 302 are located on the same arc surface as the outer surface of the magnetic steel 4 .

[0033] It can be understood that, since the outer surfaces of the Z-shaped first wedge 301 and the reverse Z-shaped second wedge 302 are located on the same arc surface as the outer surface of the magnetic steel 4, they together constitute a rotor outer circle without a slot.

[0034] As an implementation manner, the first wedge 301 and the second wedge 302 are both made of non-magnetic conductive materials.

[0035] Since the first wedge 301 and the second wedge 302 are both made of non-magnetic conductive materials, the magnetic leakage between the magnetic poles is reduced compared with the prior art, thereby improving the performance of the motor.

[0036] The installation instructions of the brushless DC motor proposed in this embodiment are as follows:

[0037] First, apply adhesive to the surfaces of the Z-shaped first wedge 301, the inverted Z-shaped second wedge 302 of the first set of wedge assemblies 3, and the Z-shaped first wedge 301, the inverted Z-shaped second wedge 302 of the second set of wedge assemblies 3 that are in contact with the rotor false tooth 2, and install them on the T-shaped rotor false tooth 2; then apply adhesive to the surfaces of the inverted Z-shaped second wedge 302 of the first set of wedge assemblies 3, the Z-shaped first wedge 301 of the second set of wedge assemblies 3 that are in contact with the magnetic steel 4, and apply adhesive to the surfaces of the magnetic steel 4 that are in contact with the inverted Z-shaped second wedge 302 of the first set of wedge assemblies 3, and the Z-shaped first wedge 301 of the second set of wedge assemblies 3; finally, insert the magnetic steel 4 between the inverted Z-shaped second wedge 302 of the first set of wedge assemblies 3 and the Z-shaped first wedge 301 of the second set of wedge assemblies 3.

[0038] The advantages of the brushless DC motor proposed in the present invention are: the magnet is matched with the concave and convex grooves of the wedge, which increases the force-bearing area of ​​the magnet, makes the magnet more firmly fixed, and can greatly reduce air friction loss; since the wedge is made of non-magnetic material, the leakage flux between the magnetic poles is greatly reduced, ensuring the performance of the motor; the magnet is easy to place and the production cost is low.

[0039] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A brushless DC motor, characterized in that: The invention comprises a rotor core and a plurality of magnetic steels arranged on the outer circumferential surface of the rotor core at intervals along the axial direction of the rotor core; wherein a plurality of rotor false teeth are distributed on the outer circumferential surface of the rotor core, a set of wedge assemblies is arranged on each rotor false tooth, and each magnetic steel is arranged between two adjacent sets of wedge assemblies; The rotor false teeth are T-shaped structures with concave sides, and the bottom of the rotor false teeth of the T-shaped structure is fixedly connected to the outer periphery of the rotor core; Each set of wedge assemblies includes a first Z-shaped wedge and a second inverted Z-shaped wedge. The first Z-shaped wedge and the second inverted Z-shaped wedge are respectively clamped on both sides of the rotor false teeth of the T-shaped structure.

2. The brushless DC motor according to claim 1, characterized in that: The cross-section of the magnetic steel is arc-shaped, and step-like structures are arranged at both ends of the arc-shaped magnetic steel. The two adjacent sets of wedge assemblies include a first set of wedge assemblies and a second set of wedge assemblies. The magnetic steel is arranged between the first set of wedge assemblies and the second set of wedge assemblies, and one end of the magnetic steel is clamped on one side of the Z-shaped first wedge in the first set of wedge assemblies, and the other end of the magnetic steel is clamped on one side of the inverted Z-shaped second wedge in the second set of wedge assemblies.

3. The brushless DC motor according to claim 1, characterized in that: The Z-shaped first wedge and the reverse Z-shaped second wedge are respectively bonded to the two sides of the rotor false tooth of the T-shaped structure by using adhesive.

4. The brushless DC motor according to claim 2, characterized in that: One end of the magnetic steel is bonded to one side of the Z-shaped first wedge in the first set of wedge assemblies by using adhesive, and the other end of the magnetic steel is bonded to one side of the reverse Z-shaped second wedge in the second set of wedge assemblies by using adhesive.

5. The brushless DC motor according to claim 2, characterized in that: The outer surfaces of the Z-shaped first wedge and the reverse Z-shaped second wedge are located on the same arc surface as the outer surface of the magnetic steel.

6. The brushless DC motor according to claim 1, characterized in that: The first wedge and the second wedge are both made of non-magnetic conductive materials.

Images