TWI900966B - Motor device for fan - Google Patents

Abstract

A motor device for a fan comprises a shaft, two bearing modules, a housing module, an outer rotor module, a heat sink, and an inner stator module. The bearing modules are spaced apart along an axial direction relative to the shaft. The housing module is mounted on the bearing modules and is rotatable about the shaft. The heat sink is positioned around the shaft and within the housing module. The inner stator module includes a stator ring that surrounds the shaft and is spaced apart from the shaft by a distance, and a plurality of windings wound around the stator ring. The windings are located at the orthographic projection of the heat sink along the axial direction. With the above arrangement, the inner stator module can dissipate heat through the heat sink, and a heat dissipation air duct can be provided through the gap with the shaft, thereby improving the heat dissipation effect.

Description

Motor device for fan

The present invention relates to a power device, and more particularly to a motor device for a fan.

The current mainstream motor device used in fans utilizes an inner stator module and an outer rotor module. The fan blades are mounted on the outer side of the outer rotor module, while the inner stator module is fixedly mounted around the motor's axis, allowing the outer rotor module to directly drive the blades. However, with this design, because the inner stator module is located at the center of the motor, heat from the inner stator module's windings is difficult to dissipate during motor operation. This can lead to overheating and malfunctions over time.

Therefore, the object of the present invention is to provide a motor device for a fan that can enhance heat dissipation effect.

Therefore, the motor device of the present invention applied to the fan includes a shaft, two bearing modules, a housing module, an outer rotor module, a heat sink, and an inner stator module.

The axis extends along an axial direction.

The bearing modules are spaced apart and arranged on the axis along the axial direction.

The housing module surrounds the axis, and the two ends of the housing module along the axis are respectively arranged on the bearing modules, and can rotate around the axis.

The outer rotor module is arranged on the housing module around the axis.

The heat sink is sleeved on the axis and located inside the housing module.

The inner stator module is arranged on the heat sink corresponding to the outer rotor module and is located within the outer shell module. The inner stator module includes a stator ring portion that surrounds the axis and is spaced apart from the axis by a distance, and a plurality of windings that surround the axis and are wound around the stator ring portion. The windings are located at the orthographic projection of the heat sink along the axis.

The present invention has the following advantages: by providing a heat sink sleeved on the shaft, arranging the inner stator module on the heat sink, and spacing the stator ring from the shaft by a specified distance, not only can the inner stator module dissipate heat through the heat sink, but also, by providing an air duct through the gap between the stator ring and the shaft. When air flows through the gap, it also helps to remove heat energy from the windings, thereby significantly improving the heat dissipation effect of the motor.

Before the present invention is described in detail, it should be noted that similar elements are denoted by the same reference numerals in the following description.

Referring to Figures 1, 2, and 3, a first embodiment of a motor device for a fan according to the present invention includes a shaft 2, two bearing modules 3, a housing module 4, an outer rotor module 5, a heat sink 6, and an inner stator module 7. The first embodiment may also optionally include a thermally conductive film 8.

The shaft 2 is in the shape of a hollow tube, extending along an axial direction L, and has a radially extending annular flange 21.

The bearing modules 3 are spaced apart on the shaft 2 along the axial direction L, and can be implemented using ball bearings, for example.

The housing module 4 surrounds the shaft 2, and the two ends of the housing module 4 along the axial direction L are respectively disposed on the bearing modules 3, and can rotate around the shaft 2. The housing module 4 includes an upper cover 41 surrounding the shaft 2, a shell 42, and a lower cover 43.

The upper cover 41 is generally barrel-shaped, the housing 42 is generally hollow and cylindrical, and the lower cover 43 is generally disc-shaped. The upper cover 41 and the lower cover 43 are spaced apart along the axial direction L and each surrounds the bearing modules 3, allowing rotation about the axis 2 via the bearing modules 3. The housing 42 is located between the upper cover 41 and the lower cover 43 and surrounds the heat sink 6 and the inner stator module 7. The housing 42's ends along the axial direction L are connected to the upper cover 41 and the lower cover 43, respectively. The housing 42 cooperates with the upper cover 41 and the lower cover 43 to define a receiving space 44 . The receiving space 44 is used to receive the heat sink 6 and the inner stator module 7 .

In this embodiment, the upper cover 41 and the lower cover 43 are assembled by a plurality of bolts 45 , but they may also be assembled by interlocking, snapping, etc., without being limited thereto.

It is worth noting that the upper cover 41 and the lower cover 43 may also be selectively formed with a plurality of through holes (not shown) or heat dissipation fins (not shown) to enhance heat dissipation efficiency.

The outer rotor module 5 and the inner stator module 7 are mounted on the outer housing module 4, for example, on the inner side of the housing 42, around the shaft 2. When the motor is operating, the outer rotor module 5 rotates about the shaft 2, driving the outer housing module 4 to rotate synchronously around the shaft 2, thereby causing the plurality of fan blades (not shown) connected to the outer housing module 4 to rotate in conjunction.

The heat sink 6 is generally disc-shaped, with the shaft 2 passing through its center point and being sleeved onto the shaft 2. It is located within the housing 44 of the housing module 4. The heat sink 6 is made of a metal material such as aluminum, an aluminum alloy, or copper. The heat sink 6 includes a mounting ring 61 that surrounds the shaft 2 and a heat sink ring 62 that surrounds the mounting ring 61. The mounting ring 61 is annular and rests against the upper plane of the flange 21 of the shaft 2 in Figure 1, securing the mounting ring 61 to the flange 21. The heat dissipation ring portion 62 is radially extended outward from the mounting ring portion 61 and is annular. In this embodiment, the heat dissipation plate 6 and the inner stator module 7 are assembled by locking with a plurality of bolts 63, but the assembly can also be performed by interlocking, locking, etc., without limitation.

The inner stator module 7 is disposed on the heat sink 6 corresponding to the outer rotor module 5 and is located in the accommodation space 44 within the outer shell module 4. It includes a stator ring portion 71, a plurality of windings 72, and a plurality of assembly portions 73.

The stator ring 71 is generally annular, encircling the shaft 2 and spaced apart from the shaft 2 by a distance d1. The radial distance d1 between the inner side of the stator ring 71 and the shaft 2 is smaller than the radial length d2 of the windings 72.

The windings 72 encircle the shaft 2 and wrap around the stator ring 71. For clarity, only the windings 72 are depicted in FIG1 . Those skilled in the art will appreciate that the windings 72 are wound around the remaining corresponding locations on the stator ring 71 . The windings 72 are located at the orthographic projection of the heat sink 6 along the axial direction L, for example, at the orthographic projection of the heat sink ring 62 along the axial direction L. That is, the heat dissipation ring 62 of the heat dissipation plate 6 is arranged corresponding to the position of the windings 72, so that the radial area of the heat dissipation ring 62 overlaps as much as possible with the radial area of the windings 72, and the windings 72 and the heat dissipation ring 62 are close to each other along the axial direction L to improve the heat dissipation efficiency of the windings 72 through the heat dissipation plate 6. For example, the distance d3 between the windings 72 and the heat dissipation plate 6 along the axial direction L is designed to be less than the distance d1 between the stator ring 71 and the shaft 2, or less than 1/3 of the length d2, or less than 2 mm, or approximately equal to the thickness of the thermal conductive film 8.

The assembly portions 73 are columnar, extending along the axial direction L, and connected to the inner side surface of the stator ring portion 71 , and are respectively used for the bolts 63 to pass through and be screwed to fix the assembly to the heat sink 6 .

The thermally conductive film 8 is attached to the heat sink 6 and located between the heat sink 6 and the windings 72. By adjusting the distance d3 between the windings 72 and the heat sink 6 and the thickness of the thermally conductive film 8, the thermally conductive film 8 can be sandwiched between the heat sink 6 and the windings 72 to further enhance heat dissipation efficiency through heat conduction during contact. The thermally conductive film 8 is a medium with a thermally conductive effect, such as a thermally conductive soft material (e.g., a thermally conductive silicone film). The thermally conductive silicone film is made of silicone as a base material and is added with various auxiliary materials such as thermal conductive powder and flame retardant. The thermal conductive film 8 can also be replaced with thermal conductive glue to achieve the effect of improving heat dissipation.

Based on the above description, the effects of this embodiment are as follows:

First, by installing the heat sink 6 sleeved around the shaft 2 and positioning the inner stator module 7 on the heat sink 6, with the stator ring 71 spaced a distance d1 from the shaft 2, not only does this provide a path for the windings 72 to dissipate heat through the heat sink 6, but the gap between the stator ring 71 and the shaft 2 also creates an air duct. When air flows through this gap, it also helps remove heat from the windings 72. Consequently, the motor's heat dissipation efficiency is significantly enhanced.

Second, by installing the thermally conductive film 8 between the heat sink 6 and the windings 72 , the heat dissipation efficiency can be improved. Moreover, the thermally conductive film 8 is not only easy to disassemble, but its insulating properties can also improve the insulation effect between the heat sink 6 and the windings 72 .

Referring to FIG. 4 , there is shown a second embodiment of the motor device of the present invention applied to a fan. The second embodiment is similar to the first embodiment, and the difference between the second embodiment and the first embodiment is that:

The housing module 4 includes a barrel-shaped upper cover 41 and a disc-shaped lower cover 43 surrounding the shaft 2. The upper cover 41 and the lower cover 43 are respectively mounted on the bearing modules 3 and cooperate with each other to define the accommodating space 44. The upper cover 41 surrounds the heat sink 6 and the inner stator module 7, and accommodates the outer rotor module 5 inside.

The windings 72 of the inner stator module 7 are close to the heat sink 6, so that the windings 72 are close to or abut against the heat sink ring 62, and the position of the flange 21 is close to the corresponding bearing module 3, so that the heat sink 6 is close to the lower cover 43.

Thus, the second embodiment can achieve the same purpose and effect as the first embodiment. Furthermore, by omitting the housing 42 (see FIG. 1 ), positioning the windings 72 closer to the heat sink 6 , and positioning the flange 21 closer to the corresponding bearing module 3 , the length of the motor along the axial direction L can be reduced, resulting in a smaller footprint for the second embodiment.

In summary, the present invention, when applied to a motor device for a fan, can indeed achieve the purpose of the present invention.

However, the above description is merely an example of the present invention and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made within the scope of the patent application and the contents of the patent specification of the present invention are still within the scope of the present patent.

2: Shaft 21: Flange 3: Bearing module 4: Housing module 41: Upper cover 42: Housing 43: Lower cover 44: Storage space 45: Bolts 5: Outer rotor module 6: Heat sink 61: Mounting ring 62: Heat sink ring 63: Bolts 7: Inner stator module 71: Stator ring 72: Windings 73: Assembly 8: Thermal conductive film L: Axial direction d1: Pitch d2: Length d3: Distance

Other features and functions of the present invention are clearly illustrated in the accompanying drawings, wherein: Figure 1 is a schematic cross-sectional view of a first embodiment of a motor device for a fan according to the present invention; Figure 2 is an exploded perspective view of the first embodiment; Figure 3 is an exploded perspective view of the first embodiment from another angle; and Figure 4 is a schematic cross-sectional view of a second embodiment of a motor device for a fan according to the present invention.

2: Shaft 21: Flange 3: Bearing module 4: Housing module 41: Upper cover 42: Housing 43: Lower cover 44: Storage space 45: Bolts 5: Outer rotor module 6: Heat sink 61: Mounting ring 62: Heat sink ring 63: Bolts 7: Inner stator module 71: Stator ring 72: Windings 73: Assembly 8: Thermal conductive film L: Axial direction d1: Pitch d2: Length d3: Distance

Claims (9)

A motor device for a fan comprises: A shaft extending along an axial direction; Two bearing modules spaced apart along the axial direction from the shaft; A housing module surrounding the shaft, with the ends of the housing module along the axial direction respectively mounted on the bearing modules, and rotatable about the shaft; An outer rotor module disposed on the housing module around the shaft; A heat sink sleeved on the shaft and located within the housing module; and An inner stator module is disposed on the heat sink corresponding to the outer rotor module and is located within the outer housing module. The inner stator module includes a stator ring that surrounds the axis and is spaced apart from the axis by a distance, and a plurality of windings that surround the axis and are wound around the stator ring. The windings are located at the orthographic projection of the heat sink along the axis. In the motor device for a fan as claimed in claim 1, the heat sink is made of aluminum. As described in claim 1, the motor device for a fan comprises a heat sink including a mounting ring disposed around the axis and a heat sink surrounding the mounting ring, and the windings are located at the orthographic projection of the heat sink along the axis. In the motor device for a fan as described in claim 3, the shaft has a radially extending flange for the mounting ring to be clamped. The motor device for a fan as described in claim 1, wherein the inner stator module further includes a plurality of assembly portions extending from the stator ring and used for assembly to the heat sink, and the radial distance between the inner side surface of the stator ring and the axis is less than the radial length of the windings. The motor device for a fan as described in claim 1 further includes a thermally conductive sheet disposed on the heat sink and between the heat sink and the windings. The motor device for a fan as described in claim 1, wherein the outer rotor module is arranged on the inner side of the outer shell module around the inner stator module. A motor device for a fan as described in claim 1, wherein the outer casing module includes an upper cover, a shell and a lower cover surrounding the axis, the upper cover and the lower cover are respectively arranged on the bearing modules, the two ends of the shell along the axial direction are respectively connected to the upper cover and the lower cover, the shell surrounds the heat sink and the inner stator module and provides the outer rotor module for arrangement on the inner side. As described in claim 1, the motor device for a fan comprises a barrel-shaped upper cover and a disc-shaped lower cover surrounding the axis, the upper cover and the lower cover are respectively arranged on the bearing modules, the upper cover is arranged around the heat sink and the inner stator module, and the outer rotor module is arranged on the inner side.