Brushless direct current motor

Abstract

The brushless direct current motor comprises a casing and a motor shaft, the front end of the casing is provided with a heat dissipation through hole, the tail end of the casing is provided with a heat dissipation through groove, and the motor shaft penetrates out of the tail end of the casing and is detachably connected with fan blades; the fan blades are provided with middle rings, mounting holes are formed in the middle rings, the motor shaft is provided with an external expansion part, the section diameter of the external expansion part is larger than that of the mounting holes, the tail of the motor shaft is in threaded connection with an end bolt, and the section diameter of the end of the end bolt is larger than that of the mounting holes, so that the end bolt stops the middle rings from being freely separated from the motor shaft. The fan is novel in structure, convenient to maintain, compact and reasonable, the fan blades are externally arranged, and the internal space of the machine shell is not occupied.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, and particularly relates to a brushless DC motor. Background Art

[0002] Compared with traditional brushed DC motors, brushless DC motors adopt different design and control methods. Due to their advantages such as high efficiency, long service life, and high power density, brushless DC motors are widely used in fields such as automobiles, industrial industrial control, mechanical automation, and household appliances.

[0003] Existing brushless DC motors dissipate heat through heat dissipation holes on the surface, with poor heat dissipation effect. When operating at high speeds, there is a problem of large heat generation, which easily leads to failures and affects the service life.

[0004] The existing patent document (Publication No.: CN215733890U) discloses "a brushless DC motor", and its technical solution is that a suction fan blade is fixedly installed at one end of the output shaft located inside the housing, which can accelerate heat dissipation. However, since the suction fan blade is arranged inside the housing, it occupies the internal space of the housing, and the suction fan blade needs to be disassembled from the housing for maintenance, which is inconvenient to operate and has low efficiency. Summary of the Invention

[0005] The purpose of the utility model is to solve the above technical problems existing in the prior art, and provide a brushless DC motor with novel structure, external fan blades, convenient for maintenance, not occupying the internal space of the housing, and compact and reasonable.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] A brushless DC motor, comprising: a housing and a motor shaft, characterized in that: a heat dissipation through hole is provided at the front end of the housing, a heat dissipation through groove is provided at the rear end of the housing, the motor shaft passes through the rear end of the housing and is detachably connected with a fan blade; the fan blade is provided with a middle ring, the middle ring is provided with a mounting hole, the motor shaft is provided with an outward expansion part, the cross-sectional diameter of the outward expansion part is larger than the cross-sectional diameter of the mounting hole, and the tail of the motor shaft is screwed with an end bolt, the cross-sectional diameter of the end of the end bolt is larger than the cross-sectional diameter of the mounting hole, so that the end bolt blocks the middle ring from freely detaching from the motor shaft. This brushless DC motor has a novel structure, external fan blades, is convenient for maintenance, does not occupy the internal space of the housing, and is compact and reasonable.

[0008] Furthermore, it further includes an outer ring, and fixing ribs are provided between the outer ring and the housing to ensure the connection strength between the outer ring and the housing; the outer ring is provided with ears, and mounting counterbores are provided on the ears. Screws are inserted into the mounting counterbores to fix the whole to the designated position of the mechanical equipment, improving the installation convenience.

[0009] Furthermore, a limiting groove is provided on the middle ring, and the limiting groove communicates with the mounting hole. A flat key corresponding to the limiting groove is provided on the outer wall of the motor shaft. Aligning the limiting groove with the flat key and sleeving the middle ring on the motor shaft realizes positioning and docking, reducing the assembly difficulty. The flat key is connected with the limiting groove in a matching manner, restricting the relative rotation of the fan blade relative to the motor shaft and improving the installation stability of the fan blade.

[0010] Furthermore, a protective cover is screwed to the tail end of the housing, and the protective cover covers the fan blade. A fixing through groove is provided on the protective cover. The protective cover not only protects the fan blade but also plays a role in wind gathering, improving the heat dissipation effect.

[0011] Furthermore, the housing includes a front housing and a rear end cover. The rear end cover is fixedly connected to the front housing through bolts. Both ends of the motor shaft pass through the rear end cover and the front housing respectively. The front housing and the rear end cover can be detachably separated, facilitating the maintenance of the internal motor components, which is flexible and convenient.

[0012] Furthermore, heat dissipation fins are distributed around the housing, improving the overall heat dissipation performance.

[0013] Due to the adoption of the above technical solutions, the present utility model has the following beneficial effects:

[0014] 1. The fan blade can be detachably separated from the motor shaft, which is convenient for replacement in case of damage. During installation, the mounting hole of the middle ring is sleeved on the tail end of the motor shaft, making the middle ring abut against the outward expansion part. Then, a head bolt is installed at the tail of the motor shaft. The head of the head bolt blocks the free detachment of the middle ring from the tail end of the motor shaft. The middle ring is clamped bidirectionally by the outward expansion part and the head of the head bolt and cannot move freely, ensuring reliable installation; the fan blade is externally placed, facilitating maintenance and not occupying the internal space of the housing, which is compact and reasonable.

[0015] 2. Aligning the limiting groove with the flat key and sleeving the middle ring on the motor shaft realizes positioning and docking, reducing the assembly difficulty. The flat key is connected with the limiting groove in a matching manner, restricting the relative rotation of the fan blade relative to the motor shaft and improving the installation stability of the fan blade.

[0016] 3. Fixed ribs are provided between the outer ring and the housing, ensuring the connection strength between the outer ring and the housing. The outer ring provides circumferential support to the housing through the fixed ribs, improving the stability of the housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present utility model will be further described below with reference to the accompanying drawings:

[0018] Figure 1 is a schematic structural diagram of Embodiment 1 of the present utility model;

[0019] Figure 2 is a schematic structural diagram of the connection between the housing and the fan blade in Embodiment 1;

[0020] Figure 3Schematic diagram of the structure for the connection between the fan blade and the motor shaft in Embodiment 1;

[0021] Figure 4 Schematic diagram of the structure of the rear end cover in Embodiment 1;

[0022] Figure 5 Schematic diagram of the structure of the protective cover in Embodiment 1;

[0023] Figure 6 Schematic diagram of the structure of Embodiment 2 of the present utility model.

[0024] In the figure: 1 - housing; 2 - front housing; 3 - rear end cover; 4 - motor shaft; 5 - heat dissipation through hole; 6 - heat dissipation through groove; 7 - fan blade; 8 - middle ring; 9 - mounting hole; 10 - outward expansion part; 11 - end head bolt; 12 - limit groove; 13 - flat key; 14 - protective cover; 15 - fixing through groove; 16 - heat dissipation fin; 17 - outer ring; 18 - fixing rib; 19 - ear part; 20 - mounting counterbore; 21 - convex part. Detailed implementation manners

[0025] As Figures 1 to 5 shown, it is Embodiment 1 of the present utility model

[0026] A brushless DC motor, comprising: a housing 1 and a motor shaft 4. The housing 1 includes a front housing 2 and a rear end cover 3. The rear end cover 3 and the front housing 2 are fixedly connected by bolts. Both ends of the motor shaft 4 pass through the rear end cover 3 and the front housing 2 respectively. The front housing 2 and the rear end cover 3 can be detachably separated, which is convenient for overhauling the internal motor components, flexible and convenient.

[0027] A stator and a rotor are provided inside the front housing 2. A coil is wound on the stator. The stator is rotationally connected to the rotor. The motor shaft 4 is arranged on the rotor. The above structure belongs to the prior art and will not be elaborated here.

[0028] Heat dissipation through holes 5 are provided on the front housing 2, heat dissipation through grooves 6 are provided on the rear end cover 3, and the tail end of the motor shaft 4 passing through the housing 1 is connected with a fan blade 7. The cold air generated by the rotation of the fan blade 7 is blown into the housing 1 through the heat dissipation through groove 6 and flows out from the heat dissipation through hole 5. The air circulates axially, accelerating the discharge of the heat inside the housing 1 and preventing heat accumulation inside the housing 1, with high heat dissipation efficiency.

[0029] The fan blade 7 is provided with a middle ring 8, and mounting holes 9 are provided on the middle ring 8. An outward expansion part 10 is provided on the motor shaft 4. The cross-sectional diameter of the outward expansion part 10 is larger than the cross-sectional diameter of the mounting hole 9. The tail of the motor shaft 4 is screwed with an end head bolt 11. The cross-sectional diameter of the end of the end head bolt 11 is larger than the cross-sectional diameter of the mounting hole 9, so that the end head bolt 11 blocks the middle ring 8 from freely detaching from the motor shaft 4.

[0030] The fan blade 7 can be detachably separated from the motor shaft 4, which is convenient for replacement in case of damage. During installation, the mounting hole 9 of the middle ring 8 is sleeved on the tail end of the motor shaft 4, so that the middle ring 8 abuts against the outward expansion part 10. Then, an end bolt 11 is installed at the tail of the motor shaft 4, and the end of the end bolt 11 blocks the middle ring 8 from freely detaching from the tail end of the motor shaft 4. The middle ring 8 is clamped bidirectionally by the outward expansion part 10 and the end of the end bolt 11 and cannot move freely, ensuring reliable installation. The fan blade 7 is externally placed, which is convenient for maintenance and does not occupy the internal space of the machine shell 1, with a clever design.

[0031] A limit groove 12 is provided on the middle ring 8, and the limit groove 12 communicates with the mounting hole 9. A flat key 13 corresponding to the limit groove 12 is provided on the outer wall of the tail end of the motor shaft 4. Aligning the limit groove 12 with the flat key 13 to sleeved the middle ring 8 on the motor shaft 4 realizes positioning and docking, reducing the assembly difficulty. The flat key 13 is connected with the limit groove 12 in a matching manner, restricting the relative rotation of the fan blade 7 relative to the motor shaft 4 and improving the installation stability of the fan blade 7.

[0032] A protective cover 14 is connected to the rear end cover 3, and the protective cover 14 covers the fan blade 7. A fixed through groove 15 is provided on the protective cover 14, which is conducive to the air circulation inside and outside. A boss part 21 is provided on the rear end cover 3, and an external thread is provided on the outer peripheral wall of the boss part 21. An internal thread is provided on the inner wall of the protective cover 14, realizing the threaded connection and cooperation between the rear end cover 3 and the protective cover 14, with reliable fixation and convenient disassembly and assembly. The protective cover 14 not only protects the fan blade 7 but also plays a role in wind gathering, improving the heat dissipation effect.

[0033] Radiating fins 16 are distributed around the front housing 2, improving the overall heat dissipation performance.

[0034] As Figure 6 shown, this is the second embodiment of the present invention

[0035] Based on the technical solution of the first embodiment, the present invention further includes an outer ring 17. A fixing rib 18 is provided between the outer ring 17 and the machine shell 1, ensuring the connection strength between the outer ring 17 and the machine shell 1. The outer ring 17 provides circumferential support to the machine shell 1 through the fixing rib 18, improving the stability of the machine shell 1. An ear part 19 is provided on the outer ring 17, and a mounting counterbore 20 is provided on the ear part 19. Screws are inserted into the mounting counterbore 20 to fix the whole to the designated position of the mechanical equipment, improving the installation convenience.

[0036] The above are only the specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all covered by the protection scope of the present invention.

Claims

1. A brushless DC motor, comprising: Casing and motor shaft, Features: The front end of the housing is provided with a heat dissipation through hole, the rear end of the housing is provided with a heat dissipation through groove, and the motor shaft passes through the rear end of the housing and is detachably connected with a fan blade; The fan blade is provided with a middle ring, and a mounting hole is provided on the middle ring. The motor shaft is provided with an outward expansion portion, and the cross-sectional diameter of the outward expansion portion is larger than the cross-sectional diameter of the mounting hole. The tail of the motor shaft is screwed with an end bolt, and the cross-sectional diameter of the end of the end bolt is larger than the cross-sectional diameter of the mounting hole, so that the end bolt can prevent the middle ring from freely detaching from the motor shaft.

2. A brushless DC motor according to claim 1, characterized in that: It also includes an outer ring, a fixing rib is arranged between the outer ring and the housing, an ear is arranged on the outer ring, and a mounting countersunk hole is arranged on the ear.

3. A brushless DC motor according to claim 1, characterized in that: The middle ring is provided with a limiting groove, the limiting groove is communicated with the mounting hole, and the outer wall of the motor shaft is provided with a flat key corresponding to the limiting groove.

4. A brushless DC motor according to claim 1, characterized in that: A protective cover is screwed on the rear end of the casing, the protective cover covers the fan blades, and a fixing through slot is arranged on the protective cover.

5. A brushless DC motor according to claim 1, characterized in that: The housing comprises a front housing and a rear end cover, the rear end cover and the front housing are connected and fixed by bolts, and two ends of the motor shaft pass through the rear end cover and the front housing respectively.

6. A brushless DC motor according to claim 1, characterized in that: The casing is surrounded by heat dissipation fins.

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