Thin direct-current brushless outer rotor motor

Abstract

The utility model belongs to motor technical field discloses a thin type direct current brushless outer rotor motor, including the casing, the casing is the open cylinder of one end, the coaxial line is placed in the fixed shaft of casing, the coaxial line is placed and is equipped with the stator core of outside sleeve of shaft, the magnetic strip is fixed on the casing inside peripheral wall, the end cover is equipped with the open end of casing, the end cover is the disc -shaped of inside hollow, and the end cover is close to the open -mouthed of casing end, and the open end of casing is inlaid into the inside of end cover, the stator core is fixedly connected with the end cover, and the one end of shaft is passed through the end cover and is connected with the end cover rotation, the outside peripheral wall fixed support of end cover open end, and the support is located between the two ends of end cover and casing along the shaft axial direction and is away from each other, effectively reduced the thickness of motor along the shaft axial direction, realized the design of motor structure thin type.

Description

Technical Field

[0001] This utility model belongs to the field of motor technology, specifically relating to a thin DC brushless external rotor motor. Background Technology

[0002] With the increasing demand for miniaturized drive motors in space-constrained applications such as robot joints and drone servos, existing external rotor motors suffer from excessively large axial dimensions due to their double-end flange connections and independent mounting brackets, making them unsuitable for compact installations. Especially in high-torque applications, traditional motors often further increase the end cap thickness to ensure structural strength, contradicting the goal of a thinner design. Furthermore, the multi-component stacking design of rotor support and sealing structures in existing technologies not only increases axial space requirements but also affects assembly accuracy. Therefore, a thin DC brushless external rotor motor is needed to reduce its axial dimension. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a thin DC brushless external rotor motor to reduce the axial dimension of the motor.

[0004] The objective of this utility model can be achieved through the following technical solutions:

[0005] A thin DC brushless external rotor motor includes a housing, which is cylindrical with one end open;

[0006] A rotating shaft placed coaxially is fixed inside the housing;

[0007] A stator core, placed coaxially, is fitted on the outer side of the rotating shaft;

[0008] A magnetic strip is fixed on the inner peripheral wall of the housing;

[0009] The shell opening end is provided with an end cap, which is a hollow disc shape, and the end cap is open near the shell end, with the shell opening end extending into the inside of the end cap;

[0010] The stator core is fixedly connected to the end cover, and one end of the rotating shaft passes through the end cover and is rotatably connected to the end cover.

[0011] A bracket is fixed to the outer peripheral wall of the end cap opening, and the bracket is located between the two ends of the end cap and the housing that are far apart from each other along the axis of rotation.

[0012] The end cap has a sleeve with open ends fixed inside. The sleeve and the rotating shaft are placed on the same axis. The rotating shaft is rotatably connected to the inside of the sleeve. The stator core is fixedly sleeved on the outer peripheral wall of the sleeve.

[0013] One end of the sleeve extends to the outer side of the end cap away from the housing and is fixedly fitted with a sealing ring, and the sealing ring is attached to and fixedly connected to the end cap away from the housing.

[0014] An oil seal is provided at the end of the sleeve away from the housing. The oil seal is fixed to the inner circumferential wall of the sleeve. The rotating shaft passes through the oil seal and is rotatably connected to it. The oil seal, the sleeve, and the rotating shaft are in contact to form a liquid-tight seal.

[0015] A retaining ring is provided on the peripheral wall of the end of the shaft that passes through the end cover;

[0016] The shaft has a threaded section located on the side of the retaining ring away from the end cover.

[0017] The bracket is equipped with a temperature control unit for monitoring the temperature of the external rotor motor.

[0018] The temperature control unit includes a self-resetting temperature controller or a manual temperature controller.

[0019] There are two temperature control units, one of which is a self-resetting temperature controller and the other is a manual temperature controller.

[0020] The bracket has multiple connection holes.

[0021] The beneficial effects of this utility model are:

[0022] 1. This application eliminates the traditional double-end-cover structure by placing the stator core inside a single-end-opening housing and using a single end cover, directly reducing the axial occupancy of one end cover; by adopting a nested connection structure between the housing and the end cover, the open end of the housing can be directly inserted into the end cover, eliminating the axial space required for traditional flange connections; by integrating the bracket into the outer peripheral wall of the end cover and placing it between the end cover and the housing end face, it ensures that the bracket does not add extra axial dimensions, effectively reducing the thickness of the motor along the shaft axis and achieving a thinner motor structure design;

[0023] 2. By using an elastic sealing ring in the radial direction to achieve a static seal between the sleeve and the end cover, external dust and liquid can be effectively prevented from entering. In the axial direction, a special rotary oil seal is used to form a dynamic seal between the shaft and the sleeve, which can reliably prevent leakage of internal lubricating medium. This synergistic design of radial and axial dual seals not only effectively maintains the thin-structure characteristics of the motor, but also ensures the long-term sealing reliability of the motor under various operating conditions, making it suitable for use in high humidity environments. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the overall structure of the external rotor motor and impeller of this utility model;

[0026] Figure 2 This is a schematic diagram of the overall structure of the external rotor motor of this utility model;

[0027] Figure 3 This is a schematic diagram of the overall structure of the external rotor motor of this utility model from different perspectives;

[0028] Figure 4 This is a partial structural diagram of the stator core of this utility model;

[0029] Figure 5 This is a partial structural diagram of the sealing ring of this utility model;

[0030] Figure 6 This is a schematic diagram of the oil seal portion of this utility model;

[0031] Figure 7 This is a partial structural diagram of the end cap of this utility model. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0033] This combination Figures 1 to 7 This document describes an embodiment of a thin-film brushless DC external rotor motor. Specifically, the thin-film brushless DC external rotor motor is constructed with a split structure, comprising components such as a housing 100, a rotating shaft 200, a stator core 300, magnetic strips 400, end caps 500, and a bracket 501. By placing the stator core 300 within the housing 100, which has a single open end, and using a single end cap 500, the traditional double-end-cap 500 structure is eliminated, directly reducing the axial occupancy of one end cap 500. A nested connection structure between the housing 100 and the end cap 500 allows the open end of the housing 100 to be directly inserted into the end cap 500, eliminating the axial space required for traditional flange connections. By integrating the bracket 501 onto the outer peripheral wall of the end cap 500 and positioning it between the end cap 500 and the end face of the housing 100, the bracket 501 does not add any additional axial dimension, effectively reducing the thickness of the motor along the axial direction of the rotating shaft 200 and achieving a thin-film design for the motor structure.

[0034] Please refer to Figures 1 to 7 A thin DC brushless external rotor motor includes a housing 100, which is a cylindrical shape with one end open.

[0035] A rotating shaft 200 is fixed inside the housing 100, which is placed coaxially.

[0036] A stator core 300 is coaxially placed on the outer side of the rotating shaft 200;

[0037] A magnetic strip 400 is fixed on the inner peripheral wall of the housing 100;

[0038] The housing 100 has an end cap 500 at its open end. The end cap 500 is a hollow disc and is open near the end of the housing 100. The open end of the housing 100 extends into the inside of the end cap 500.

[0039] The stator core 300 is fixedly connected to the end cover 500, and one end of the rotating shaft 200 passes through the end cover 500 and is rotatably connected to the end cover 500.

[0040] A bracket 501 is fixed to the outer peripheral wall of the open end of the end cap 500. The bracket 501 is located between the two ends of the end cap 500 and the housing 100 that are axially separated from each other along the shaft 200.

[0041] It should be noted that the stator core 300 is also equipped with coil windings;

[0042] In actual use, the bracket 501 is fixedly installed with external components to effectively fix the bracket 501, end cover 500 and stator core 300;

[0043] This application eliminates the traditional double-end-cover 500 structure by placing the stator core 300 inside the single-end-open housing 100 and using a single end cover 500, directly reducing the axial occupancy of one end cover 500. By adopting a nested connection structure between the housing 100 and the end cover 500, the open end of the housing 100 can be directly inserted into the end cover 500, eliminating the axial space required for traditional flange connections. By integrating the bracket 501 into the outer peripheral wall of the end cover 500 and placing it between the end cover 500 and the end face of the housing 100, the bracket 501 does not add extra axial dimensions, effectively reducing the thickness of the motor along the axial direction of the shaft 200, and achieving a thinner motor structure design.

[0044] Preferably, a notch is provided on one side of the periphery of the end cover 500, and a terminal block is detachably connected to the inner end face of the end cover 500 at the notch. The terminal block is used for welding the enameled wire of the motor.

[0045] The end cap 500 has a sleeve 502 with both ends open. The sleeve 502 is placed coaxially with the rotating shaft 200. The rotating shaft 200 is rotatably connected to the inner side of the sleeve 502. The stator core 300 is fixedly sleeved on the outer peripheral wall of the sleeve 502. The sleeve 502 effectively improves the stability of the stator core 300.

[0046] Preferably, a bearing 700 is sleeved on the rotating shaft 200, with the inner ring of the bearing 700 fixed to the rotating shaft 200 and the outer ring of the bearing 700 fixed to the inner peripheral wall of the sleeve 502. The bearing 700 facilitates the effective rotation of the rotating shaft 200, while improving the stability of the rotating shaft 200 during rotation and reducing the possibility of the rotating shaft 200 shaking during rotation.

[0047] Preferably, the inner side of the sleeve 502 is provided with a convex ring placed on the same axis, and two bearings 700 are provided on the rotating shaft 200. The two bearings 700 are located at both ends of the convex ring, and a metal washer 701 and a wave elastic washer 702 are sleeved on the rotating shaft 200. The metal washer 701 and the wave elastic washer 702 are located at both ends of the bearing 700 near the bottom end of the inner side of the housing 100.

[0048] One end of the sleeve 502 extends to the outside of the end cap 500 away from the housing 100 and is fixedly fitted with a sealing ring 600. The sealing ring 600 is attached to and fixedly connected with the end cap 500 away from the housing 100.

[0049] An oil seal 601 is provided at the end of the sleeve 502 away from the housing 100. The oil seal 601 is fixed to the inner peripheral wall of the sleeve 502. The rotating shaft 200 passes through the oil seal 601 and is rotatably connected to it. The oil seal 601, the sleeve 502, and the rotating shaft 200 are in contact and form a liquid-tight seal.

[0050] Preferably, the sealing ring 600 can be made of materials such as nitrile rubber or fluororubber;

[0051] Preferably, the oil seal 601 is a TC type double-lip skeleton oil seal 601;

[0052] In the radial direction, a resilient sealing ring 600 achieves a static seal between the sleeve 502 and the end cover 500, effectively preventing the intrusion of external dust and liquid. In the axial direction, a dedicated rotary oil seal 601 forms a dynamic seal between the shaft 200 and the sleeve 502, reliably preventing leakage of internal lubricating media. This synergistic design of radial and axial dual seals effectively maintains the motor's slim structural characteristics while ensuring long-term sealing reliability under various operating conditions, making it suitable for use in high-humidity environments.

[0053] A retaining ring 800 is provided on the peripheral wall of the end of the shaft 200 that passes through the end cover 500;

[0054] The rotating shaft 200 is provided with a threaded part 201, which is located on the side of the retaining ring 800 away from the end cover 500;

[0055] Preferably, an annular groove is provided on the peripheral wall of the rotating shaft 200, and the retaining ring 800 is sleeved in the annular groove, and the retaining ring 800 is detachably connected to the annular groove.

[0056] Preferably, the wind turbine 202 or blades to be driven are sleeved on the rotating shaft 200, and a locking nut 203 is sleeved on the rotating shaft 200, so that the wind turbine 202 is pressed between the locking nut 203 and the retaining ring 800;

[0057] Preferably, the upper end of the rotating shaft 200 is provided with a cutting part, which makes the cross section of the end of the rotating shaft 200 with the threaded part 201 non-circular. At the same time, the impeller 202 or the blade is provided with a matching irregular groove to avoid the impeller 202 or the blade sliding relative to the rotating shaft 200 around the central axis.

[0058] The bracket 501 is equipped with a temperature control unit 900 for monitoring the temperature of the external rotor motor; by integrating the temperature control unit 900 on the bracket 501, the original thin structure advantage of the motor is maintained while real-time monitoring of the motor's operating temperature is achieved.

[0059] Preferably, the temperature control unit 900 is detachably connected to the bracket 501; this detachable connection allows for disassembly and replacement of the temperature control unit 900 during maintenance; preferably, a connecting plate is fixed to the temperature control unit 900, and the connecting plate is threadedly connected to the bracket 501 by bolts.

[0060] The temperature control unit 900 includes a self-resetting temperature controller or a manual temperature controller;

[0061] Preferably, the self-resetting temperature controller can use a BW series bimetallic strip temperature switch, which automatically disconnects the circuit when the temperature exceeds the adjustable set value (usually 70-150℃) and automatically resets after the temperature drops; or it can use a polymer positive temperature coefficient thermistor (PPTC), whose resistance value increases sharply when overheating occurs, thereby realizing circuit protection, and automatically returning to normal operation after the fault is cleared; or it can be equipped with a miniature temperature relay such as JUC-31F, which drives the contact action by the pressure change generated by the internal expanding liquid being heated.

[0062] Preferably, the manual temperature controller can be an adjustable snap-action temperature controller such as KSD301. When the temperature exceeds the set threshold, the protection device automatically trips, and the reset button pops out, requiring manual pressing to reset and restore operation; or an RY series fusible temperature fuse can be used, which permanently melts when the rated temperature is reached, requiring replacement with a new component to continue use; or a mechanical temperature indicator (such as a pointer dial) can be set in conjunction with a manual switch, allowing the operator to manually cut off or connect the circuit according to the actual situation through a visual temperature display.

[0063] The temperature control unit 900 consists of two units: one is a self-resetting temperature controller, and the other is a manual temperature controller. By simultaneously configuring both self-resetting and manual temperature controllers in the motor, a multi-level temperature protection system with complementary advantages is achieved. The self-resetting temperature controller can automatically handle instantaneous overtemperature and recover on its own, ensuring the stability of continuous motor operation. The manual temperature controller, on the other hand, serves as a reliable backup protection, providing final safety assurance in the event of a serious fault. This dual protection design maintains the compact structural advantages of the thin motor while significantly improving the reliability and safety of temperature protection. Furthermore, through the coordinated operation of the two protection mechanisms, it can intelligently distinguish between temporary overload and permanent fault conditions, avoiding malfunctions while ensuring effective protection.

[0064] The bracket 501 is provided with multiple connection holes 5011; preferably, the connection holes 5011 are threaded holes, so as to fix the bracket 501 to external components by bolts, flanges, etc.

[0065] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims of this utility model.

Claims

1. A thin-film brushless DC external rotor motor, comprising a housing (100), the housing (100) being a cylindrical shape with one end open, characterized in that: A rotating shaft (200) is fixed inside the housing (100) and placed coaxially. A stator core (300) is coaxially placed on the outside of the rotating shaft (200); A magnetic strip (400) is fixed on the inner peripheral wall of the housing (100); The housing (100) has an end cap (500) at the open end. The end cap (500) is a hollow disc and the end cap (500) is open near the end of the housing (100). The open end of the housing (100) extends into the inside of the end cap (500). The stator core (300) is fixedly connected to the end cover (500), and one end of the rotating shaft (200) passes through the end cover (500) and is rotatably connected to the end cover (500); A bracket (501) is fixed to the outer peripheral wall of the opening end of the end cap (500). The bracket (501) is located between the two ends of the end cap (500) and the housing (100) that are axially separated from each other along the shaft (200).

2. The thin-film brushless DC external rotor motor according to claim 1, characterized in that, The end cap (500) has a sleeve (502) with both ends open. The sleeve (502) and the rotating shaft (200) are placed on the same axis. The rotating shaft (200) is rotatably connected to the inside of the sleeve (502). The stator core (300) is fixedly sleeved on the outer peripheral wall of the sleeve (502).

3. The thin-film brushless DC external rotor motor according to claim 2, characterized in that, One end of the sleeve (502) extends to the outside of the end cap (500) away from the housing (100) and is fixedly fitted with a sealing ring (600), and the sealing ring (600) is attached to and fixedly connected with the end cap (500) away from the housing (100); An oil seal (601) is provided at the end of the sleeve (502) away from the housing (100). The oil seal (601) is fixed to the inner circumferential wall of the sleeve (502). The rotating shaft (200) passes through the oil seal (601) and is rotatably connected to it. The oil seal (601) is in contact with the sleeve (502) and the rotating shaft (200) to form a liquid-tight seal.

4. The thin-film brushless DC external rotor motor according to claim 3, characterized in that, A retaining ring (800) is provided on the peripheral wall of one end of the shaft (200) that passes through the end cover (500); The rotating shaft (200) is provided with a threaded part (201), which is located on the side of the retaining ring (800) away from the end cover (500).

5. The thin-film brushless DC external rotor motor according to claim 4, characterized in that, The bracket (501) is equipped with a temperature control unit (900) for monitoring the temperature of the external rotor motor.

6. The thin-film brushless DC external rotor motor according to claim 5, characterized in that, The temperature control unit (900) includes a self-resetting temperature controller or a manual temperature controller.

7. The thin-film brushless DC external rotor motor according to claim 6, characterized in that, There are two temperature control units (900), one of which is a self-resetting temperature controller and the other is a manual temperature controller.

8. The thin-film brushless DC external rotor motor according to claim 1, characterized in that, The bracket (501) is provided with multiple connection holes (5011).

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