Description:Preamble to the description
[0001] The following specification particularly describes the invention, and the manner in which it has to be performed:
Description of the invention
Technical field of the invention
[0002] The present invention pertains to an aerodynamically designed external cooling fan. More specifically, the invention focuses on a cooling device designed for an electric motor facilitating effective cooling by the integration of external fan attached to the rotor shaft of the motor thereby increasing the heat dissipation and enhancing the longevity and efficiency of the electric motor.
Background of the invention

[0003] The evolution of cooling fans attached to the rotor shaft of motors is intricately connected to the development of electric motors and the increasing need for effective cooling methods. It transports us to the early stages when electric motors emerged as a dominant force in industrial environments, bringing about significant advancements in multiple industries due to their remarkable performance. However, along with their power came the formidable task of efficiently managing the heat generated during motor operation.

[0004] In the early years, engineers faced an uphill battle in tackling the heat dissipation conundrum. They resorted to basic cooling methods such as natural convection and radiation, hoping that these measures would suffice. However, as motor technologies advanced by leaps and bounds, it became abundantly clear that these conventional cooling approaches were simply inadequate to cope with the ever-increasing heat output.

[0005] Recognizing the critical importance of maintaining optimal operating temperatures for enhanced motor performance, researchers and inventors tirelessly embarked on a journey to find more effective cooling mechanisms. Their tireless efforts culminated in a groundbreaking breakthrough: the integration of cooling fans onto the rotor shaft of motors.

[0006] In today's ever-advancing technological landscape, cooling fans attached to the rotor shaft of motors have solidified their indispensable role across a wide spectrum of industries and applications. Whether it be household appliances such as washing machines, where the operation of the motor generates substantial heat, or complex industrial machinery and automotive systems, these cooling fans tries to solve the problems of overheating.

[0007] However, in the existing systems, a drawback of the currently available technology is observed wherein aluminum fins enclosed within the motor assembly are utilized for cooling purpose. This approach leads to inadequate cooling, which consequently leads to coil burn issues in the stator.

[0008] In order to overcome the drawbacks of the existing systems, several technologies were developed over the decades to provide a cooling system for electric motors.
[0009] The Patent Application No. CN214304455U entitled “Cooling Fan” discloses a cooling fan consisting of various components. The motor includes a fixed frame, a motor shell, a rotating shaft, a bearing, an impeller, a motor stator, a motor rotor, and a bearing flexible sleeve. The motor shell comprises an upper shell and a lower shell, with the lower shell fixedly connected to the fixed frame. The lower end of the rotating shaft is secured to the lower shell, while the upper end of the rotating shaft is connected to the upper shell through a bearing. The motor stator is fixed onto the lower shell, while the motor rotor is fixed onto the upper shell. The impeller is firmly attached to the upper shell using a fixing piece and is driven by the upper shell for rotation. A bearing flexible sleeve is included within the bearing to align it and reduce vibration transmission. This cooling fan incorporates a damping structure on the bearing, resulting in reduced vibration transmission and improved stability of the bearing rotation, effectively minimizing vibration production. Additionally, the blade structure of the fan adopts a curved surface design, aligning with aerodynamics principles and reducing wind noise.
[0010] The Patent Application No. CN111288004A entitled “Aerodynamics type efficient cooling fan” discloses an aerodynamics type efficient cooling fan that utilizes aerodynamic principles to achieve effective cooling. The fan consists of a main air inlet pipeline body and a main exhaust pipeline body. By allowing wind to enter a small space through a larger space, the surrounding temperature of the wind is correspondingly reduced, resulting in noticeable cooling without the need for additional auxiliary devices. The cooling fan is versatile and capable of drawing in air from dual directions, providing strong wind power. It is equipped with a thread structure abut-joint type pipeline mounting positioning mechanism, allowing for easy and quick installation in a workshop mounting hole. Furthermore, the device features a motor-driven dual-way rotating intensity transmission branch mechanism that employs gear engagement to transmit the rotating motion of the driving motor into dual-direction rotation. This enables the fan to serve multiple purposes with a single machine. Additionally, the cooling fan incorporates an aerodynamics type air flowing cooling mechanism that reduces the temperature during the high-flow process of the air.
[0011] The Patent Application No. CN211950908U entitled “Axial flow fan” discloses an axial-flow fan and includes a support frame and a motor. The support frame consists of a mounting frame, an inner cylinder, an outer cylinder, and several connecting frames. The inner cylinder is positioned inside the outer cylinder, and both are concentrically arranged. Each connecting frame is placed between the inner cylinder and the outer cylinder, with one end connected to the outer side surface of the inner cylinder and the other end connected to the inner side surface of the outer cylinder. The motor is located on the inner side of the inner cylinder, and its power output shaft coincides with the central axis of the inner cylinder and extends outside. The outer surface of the outer cylinder is fixedly connected to the mounting bracket through the support frame. The inner cylinder of the support frame is securely fixed with the motor using screws, ensuring stable fixation. The support frame is positioned between the outer cylinder and the mounting frame, improving the stability of the connection between them and consequently enhancing the overall stability of the axial-flow fan and prolonging its service life.
[0012] Hence, there is a need for a device that overcomes the drawbacks of the existing systems and the prior arts, to provide a better heat dissipation to increase the life time as well as efficiency of the electric motors.
Summary of the Invention
[0013] The present invention addresses the limitations of existing systems by introducing an aerodynamically designed cooling fan that is externally mounted on the rotor shaft of an electric motor. In this innovative design, the external fan is securely fixed to the rotor shaft using a Metric Screw 4 (M4) and becomes an integral part of the motor assembly. By incorporating the cooling fan as an external component, the present invention offers improved efficiency and performance in motor cooling.
[0014] In the present invention, the external fan is designed with careful consideration of its components and configuration. It consists of a base plate and a set of blades, both of which are meticulously optimized to facilitate efficient bi-directional airflow. Specifically, the fan is equipped with 8 straight blades, a count determined to achieve optimal performance. The disk-shaped base plate, on the other hand, is proportioned with a diameter that ranges between 70-80% of the total diameter of the attached fan. This deliberate sizing and blade count selection contribute to the fan's ability to effectively circulate air in both directions, promoting improved cooling for the motor assembly. The optimized design ensures that the cooling process is efficient, effective, and tailored to the specific requirements of the motor, ultimately enhancing its overall performance and longevity.
[0015] The present invention offers several notable advantages over conventional cooling systems for electric motors. Firstly, the aerodynamically designed cooling fan, externally attached to the rotor shaft, provides enhanced motor cooling capabilities that surpass those of traditional rotor cooling fans. This results in a significant reduction in heat generation, leading to improved motor performance and efficiency. Moreover, the optimized 8-blade configuration of the cooling fan enables bi-directional airflow, ensuring efficient and uniform cooling of the motor assembly. Additionally, by integrating the cooling fan externally, the present invention minimizes space constraints within the motor, allowing for compact and streamlined designs. Furthermore, the enhanced cooling provided by the present system contributes to a longer lifespan for the electric motor, reducing the need for frequent maintenance and replacement. Collectively, these advantages make the present invention a valuable contribution to the field of motor cooling, offering improved performance, efficiency, longevity, and space optimization.
Brief description of the drawings
[0016] The foregoing and other features of embodiments will become more apparent from the following detailed description of embodiments when read in conjunction with the accompanying drawings. In the drawings, like reference numerals refer to like elements.
[0017] Figure 1 illustrates the isometric view of the aerodynamically designed external cooling fan.
[0018] Figure 2 illustrates the isometric view of the aerodynamically designed external cooling fan showcasing the separate components and their interconnections.
[0019] Figure 3 illustrates the isometric view of the aerodynamically designed cooling fan having 8 blades fixed on the base plate, in accordance with one embodiment of the present invention.
Detailed description of the invention
[0020] Reference will now be made in detail to the description of the present subject matter, which are shown in figures. Various changes and modifications obvious to one skilled in the art to which the invention pertains are deemed to be within the spirit, scope and contemplation of the invention.
[0021] The present invention discloses a cooling device for an electric motor. The device (100) comprises of a cooling fan (101) externally mounted on the rotor shaft (102) of an electric motor (103), wherein the cooling fan is securely fixed to the rotor shaft using an M4 screw (104) and forming an integral part of the motor assembly.
[0022] Figure 1 illustrates the isometric view of the aerodynamically designed external cooling fan. In an embodiment, the device (100) comprises an aerodynamically designed cooling fan (101) wherein the cooling fan (101) is specifically engineered to enhance the airflow and maximize the cooling effect of the motor assembly; a rotor shaft (102) of the electric motor (103) The cooling fan (101) is attached to the rotor shaft (102) by means of an M4 screw (104).
[0023] Figure 2 illustrates the isometric view of the aerodynamically designed external cooling fan depicting the separate components and their interconnections. The cooling fan (101) comprises a plurality of straight blades (101a), a disk-shaped base plate (101b), and a cylindrical extension (101c). The plurality of blades (101a) on the cooling fan (101) is optimized in an 8-blade configuration. The 8- blade configuration enables bi-directional airflow, ensuring that the cooling fan efficiently circulates air in both directions, resulting in effective cooling for the motor assembly. The disk-shaped base plate (101b) of the cooling fan (101) is designed with a diameter that varies between 70-80% of the total diameter of the attached fan (101). The 70-80% optimization of size allows effective air circulation in both directions, contributing to improved cooling performance. The base plate (101b) also includes a cylindrical extension (101c) that extends from its center. The cylindrical extension is positioned on the opposite side of the base plate where the blades (101a) are fixed and has a slightly larger diameter than the rotor shaft (102) of the electric motor (103). By aligning the cylindrical extension just outside the axis of the rotor shaft, a strategic connection is established. Additionally, the cylindrical extension features a hole (106) with a diameter sufficient for fixing an M4 screw (104).
[0024] Figure 3 illustrates the cooling fan (101) comprising a plurality of straight blades (101a), a disk-shaped base plate (101b), and a cylindrical extension (101c) (not in figure as it is located on the opposite side of the base plate (101b)).
[0025] To establish and secure the connection between the cooling fan (101) and the rotor shaft (102), an M4 screw (104) is used. This screw connects the hole (106) on the cylindrical extension of the cooling fan (101) and the hole (105) on the side of the rotor shaft (102). By fastening the screw, the cooling fan (101) is firmly attached to the rotor shaft, ensuring their synchronized operation.
[0026] The straight blade fan (101) comprising the disc-shaped base (101b) blocks the axial airflow, creates a negative pressure near the center of the fan (101) facing the motor (103) wherein the negative pressure draws airflow from the opposite end of the motor (103), enhancing heat dissipation through forced convection.
[0027] The straight blade radial fan (101) provides the advantage of operating in both clockwise and counterclockwise directions. This flexibility allows the fan (101) to be mounted on either end of the motor shaft (103) or used in reversible motors without compromising cooling efficiency.
[0028] Overall, this cooling device employs an aerodynamically designed cooling fan with optimized blade configuration, a disk-shaped base plate with a cylindrical extension, and a secure connection mechanism using an M4 screw (104). These features work together to enhance cooling efficiency and promote effective cooling of the motor assembly.
[0029] The present invention brings several significant advantages over traditional cooling systems for electric motors. One key advantage is the aerodynamically designed cooling fan (101), which is externally attached to the rotor shaft (102). This innovative design enhances the cooling capabilities of the motor (103), surpassing those of conventional rotor cooling fans. As a result, heat generation is significantly reduced, leading to improved motor performance and efficiency. The optimized 8-blade configuration (101a) of the cooling fan (101) enables bi-directional axial airflow, ensuring efficient and uniform cooling throughout the motor (103) assembly. This comprehensive cooling solution contributes to the motor's longevity, reducing the need for frequent maintenance and replacement.
[0030] In addition to its superior cooling performance, the present invention offers space optimization benefits. By integrating the cooling fan (101) externally, the design minimizes space constraints within the motor (103). This allows for more compact and streamlined motor designs, maximizing the available space for other components and improving overall system efficiency. The enhanced cooling provided by this system not only improves motor performance but also extends its lifespan, leading to cost savings and improved reliability. Collectively, these notable advantages position the present invention as a valuable contribution to the field of motor cooling, offering improved performance, efficiency, longevity, and space optimization.
Reference numbers
Components Reference Numbers
Device 100
Aerodynamically designed cooling fan 101
Fan blades 101a
Base plate 101b
Cylindrical extension 101c
Rotor shaft 102
Electric Motor 103
M4 screw 104
Hole on the rotor shaft 105
Hole on the cooling fan 106
, Claims:1. A cooling device for an electric motor, the device (100) comprising:

a. an aerodynamically designed cooling fan (101) comprising a plurality of straight blades (101a), a base plate (101b), and a cylindrical extension (101c) attached externally to an electric motor (103) for cooling; and

b. an electric motor (103) with a rotor shaft (102) for mounting the cooling fan (101) externally to the motor (103), wherein the cooling fan (101) is connected to the rotor shaft (102) using a screw (104) through a plurality of holes (105,106).

2. The device (100) as claimed in the claim 1, wherein the plurality of straight blades (101a) is optimized to an 8-blade configuration of the cooling fan, enabling bi-directional radial airflow.
3. The device (100) as claimed in the claim 1, wherein the base plate (101b) is disk-shaped, and is optimized with a diameter that is 70-80% of the total diameter of the attached fan (101) to effectively circulate air in both directions.
4. The device (100) as claimed in the claim 1, wherein the base plate (101b) is having a cylindrical extension (101c), and is fixed on the opposite side of the base plate from where the plurality of the blades (101a) is attached. The diameter of the cylindrical extension is slightly larger than the diameter of the rotor shaft (102) ensuring that the cylindrical extension (101c) can easily fixed just outside the axis of the rotor shaft (102) while coinciding with the center of the base plate.

5. The device (100) as claimed in the claim 4, features the cylindrical extension (101c) that comprises a hole (106) with a diameter ample enough to accommodate the attachment of an M4 screw (104).
6. The device (100) as claimed in claim 1, wherein the rotor shaft (102) is comprising a hole (105) of a diameter that adequately accommodates secure fastening of the M4 screw (104), ensuring a reliable and secure connection.
7. The device (100) as claimed in the claim 1, wherein the connection between the cooling fan (101) and the rotor shaft (102) is established and secured by attaching an M4 screw (104) connecting the hole (106) on the cylindrical extension, and the hole (105) on the side of the rotor shaft.