TWI395873B - External cooling fan - Google Patents

Description

External pole cooling fan

The invention relates to a cooling fan, in particular to an external pole cooling fan.

Referring to FIG. 1 , a conventional external cooling fan 1 includes a bottom plate 11 , a rotating unit 12 pivoted on the bottom plate 11 , a driving unit 13 disposed on the bottom plate 11 , and a cover plate Upper cover 14 on 11.

The rotating unit 12 includes a fan wheel 121 pivoted on the bottom plate 11 and a magnet ring 122 disposed on the periphery of the fan wheel 121. The driving unit 13 is disposed on the bottom plate 11 and located on the magnet ring 122. The outer magnetic pole 131, a circuit board 132 disposed on the bottom plate 11 and electrically connected to the magnetic pole 131, and a Hall effect sensor 133 disposed on the circuit board 132.

The magnetic pole 131 is a coil-wound electromagnet. When the magnetic pole 131 is electromagnetically excited, a strong magnetic repulsive force is formed between the magnetic pole 131 and the magnet ring 122, and the Hall detector 133 detects the magnet ring. The magnetic change of 122 changes the magnetic properties of the magnetic pole 131, and the fan wheel 121 is smoothly rotated.

Since the existing external pole type cooling fan 1 needs to be provided with a plurality of magnetic poles 131, and each of the magnetic poles 131 needs to be wound with a coil, not only the production cost is high, but also the overall weight and volume are increased.

In order to improve the disadvantages of the above-described external pole type cooling fan 1, the related art has developed a single stator external pole type cooling fan 2 as shown in FIG. 2, which is improved in that the single stator external pole type cooling fan 2 has only a certain stator. 21, the stator 21 The poles 211 are respectively integrally wound around the induction coils 20, and after the energization, the induction coils 20 on the poles 211 are excited, so that the poles 211 are magnetic and are adjacent to the periphery of the fan wheel 221 The magnet ring 222 is magnetically repulsive to drive the fan wheel 221 to rotate.

Although the space waste can be reduced, since the two-pole column 211 extends integrally from the stator 21, the volume of each pole 211 is only about half of the stator 21, and therefore the two-pole column It is not easy to wind the induction coil 20 on the 211 separately.

Moreover, since the volume of each pole 211 is small, the number of turns of the induction coil 20 that can be wound by each pole 211 is relatively small, so that the driving force generated by the magnetic mutual exclusion after energization is also Smaller, the rotation speed of the fan wheel 221 is not easily improved, and the heat dissipation effect is not improved.

Accordingly, it is an object of the present invention to provide an external pole type cooling fan which is simple in construction, high in heat dissipation efficiency, and easy to manufacture.

Therefore, the external pole type cooling fan of the present invention comprises a frame unit, a fan wheel unit pivoted on the frame unit, and a driving unit for driving the fan wheel unit.

The frame unit includes a base and a central shaft protruding from the base; the fan wheel unit includes a hub pivoted on the central shaft, and a plurality of blades extending outward from the outer periphery of the hub. And a ring of magnets disposed on the outer periphery of the blade.

The driving unit includes a circuit board disposed on the base, an inductive component electrically connected to the circuit board, and an electrical connection between the circuit board and the a magnetic pole on the outer side of the magnet ring, wherein the magnetic pole has a coil base located outside the magnet ring, a coil wound around the circumference of the coil base in the axial direction of the central shaft, and an upper stack disposed on the top surface of the coil base a yoke piece, and a lower yoke piece disposed on a bottom surface of the coil base, the upper yoke piece having a top plate portion disposed on a top surface of the coil base, at least one from the top plate portion facing the magnet ring a lower magnetic piece portion extending downwardly from the side, the lower yoke piece having a bottom plate portion disposed on a bottom surface of the coil base, at least one of which cooperates with the upper magnetic piece portion and faces the magnet ring from the bottom plate portion a lower magnetic piece portion extending upward from one side, the upper magnetic piece portion and the lower magnetic piece portion being alternately arranged, and the upper magnetic piece portion and the lower magnetic piece portion are spaced apart from each other and formed A gap region between the upper magnetic sheet portion and the lower magnetic sheet portion.

The effect of the invention is that the coil is wound around the circumference of the coil base along the axial direction of the central axis, which can effectively increase the number of turns of the coil that can be wound, so as to increase the magnetic mutual repulsion caused by the energization excitation. Further, the heat dissipation efficiency is improved; and when the magnetic field is energized and excited, the radial magnetic field is generated by the upper and lower magnetic sheets to drive the hub to rotate, so that the overall structure of the invention is simple and convenient for manufacturing.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the invention.

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

Referring to FIG. 3, a first preferred embodiment of the external pole cooling fan of the present invention includes A frame unit 31, a fan unit 32 pivotally mounted on the frame unit 31, a drive unit 33 for driving the fan unit 32, and a shaft tube 34 disposed through the drive unit 33.

The frame unit 31 includes a base 311 and a central shaft 312 protruding from the base 311. The fan unit 32 includes a hub 321 pivoted on the central shaft 312, and a plurality of blades are surrounded by the outer periphery of the hub 321 A fan blade 322 extending outwardly from the space, and a magnet ring 323 disposed on an outer circumference of the blade 322.

Referring to FIGS. 3 and 4, the driving unit 33 includes a circuit board 331 disposed on the base 311, an inductive component 332 electrically connected to the circuit board 331, and an electrical connection between the circuit board 331 and the magnet ring 323. The outer magnetic pole 333 is a part of the member omitted in Fig. 3 for convenience of explanation.

Referring to FIGS. 4 and 5, the magnetic pole 333 has a coil holder 334 located outside the magnet ring 323, a coil 335 wound around the circumference of the coil holder 334 along the axial direction of the central shaft 312, and electrically connected to the circuit board 331, An upper yoke piece 336 disposed on a top surface of the coil base 334, and a lower yoke piece 337 disposed on a bottom surface of the coil base 334, the upper yoke 336 having a coil yoke disposed on the coil base a top plate portion 336' on the top surface of the 334, and an upper magnetic plate portion 338 extending downward from a side of the top plate portion 336' facing the magnet ring 323, the lower magnetic yoke piece 337 having a coil disposed on the coil a bottom plate portion 337' on the bottom surface of the seat 334, and a lower magnetic piece portion 339 extending upward from a side of the bottom plate portion 337' facing the magnet ring 323, the upper magnetic piece portion 339 The portion 338 and the lower magnet portion 339 are alternately arranged.

In the preferred embodiment, the sensing component 332 is configured to detect the The magnet ring 323 has a polar Hall sensor, and the coil holder 334 is made of an insulating material.

The shaft tube 34 is a bottom plate portion 336' through which the upper yoke piece 336 is disposed, a coil base 334 and a bottom plate portion 337' of the lower yoke piece 337 to engage the upper yoke piece 336, the coil base 334. The yoke piece 337 is slid and the drive unit 33 is positioned on the base 311. At this time, the upper yoke piece 336 is combined with the coil base 334 and the lower yoke 337, and the upper magnetic piece 338 and the lower magnetic piece 339 are spaced apart from each other and form a medium. A gap region 330 between the upper magnetic sheet portion 338 and the lower magnetic sheet portion 339.

Referring to FIGS. 3, 4, and 5, when the coil 335 of the magnetic pole 333 of the external pole cooling fan is energized, the upper and lower magnet portions 338, 339 generate a radial magnetic field, and the sensing element 332 detects The polarity of the magnet ring 323 changes, and the magnetic field of the radial magnetic field generated by the upper and lower magnetic sheets 338, 339 is controlled by the circuit board 331 to cause the upper and lower magnetic sheets 338, 339 to be generated. The magnetic properties of the radial magnetic field continue to repel each other with the magnetic force of the magnet ring 323, and the magnet ring 323 is pushed to rotate to drive the hub 321 and the blade 322 to rotate.

Since the coil 335 is axially wound around the circumference of the coil holder 334, the number of turns of the wound coil 335 can be effectively increased not only in comparison with the conventional fan, but also the magnetic mutual repulsive thrust generated after energization excitation is increased. The rotation speed of the fan wheel unit 32 is increased to improve the heat dissipation efficiency, and the winding of the coil 335 is further facilitated, so that the production of the magnetic pole 333 is more convenient.

Moreover, when the coil 335 is energized, the upper and lower magnet portions 338, 339 generate a radial magnetic field to push the fan unit 32 to rotate. The external pole type cooling fan has a simple overall structure and is easier to manufacture.

Referring to FIG. 6, a second preferred embodiment of the external pole type heat dissipating fan of the present invention is substantially the same as the first preferred embodiment. The difference is that the magnetic yoke piece 336 has a majority of the magnetic pole 333 from the top plate. The portion 336' is spaced apart downwardly from the upper magnetic sheet portion 338, and the lower yoke 337 has a plurality of lower portions extending upward from the bottom portion 337' in cooperation with the upper magnetic sheet portion 338 The magnetic sheet portion 339, the upper magnetic sheet portion 338 and the lower magnetic sheet portion 339 are alternately arranged, and each of the upper magnetic sheet portions 338 and the adjacent lower magnetic sheet portion 339 are spaced apart from each other. The upper magnetic sheet portion 338 and the lower magnetic sheet portion 339 cooperate to form a plurality of gap regions 330 interposed between the upper magnetic sheet portion 338 and the lower magnetic sheet portion 339, respectively.

By increasing the number of the upper and lower magnetic sheets 338, 339 to increase the driving force generated by the magnetic mutual repulsion, it is convenient to push the fan unit 32 to rotate, that is, in the same power situation, with the upper and lower products The increase in the number of the magnet portions 338, 339 enables the rotation of the fan unit 32 (shown in Fig. 3) to be faster; of course, when the rotational speed of the fan unit 32 is the same, with the upper and lower magnetic sheets The increase in the number of portions 338, 339 requires less power, so the preferred embodiment can effectively reduce the power consumption in addition to the efficiency of the first preferred embodiment.

Referring to FIG. 7, a third preferred embodiment of the external-pole heat-dissipating fan of the present invention is substantially the same as the second preferred embodiment. The difference is that the upper yoke 336 has a majority of each formed. The upper cutout portion 35 on the magnetic sheet portion 338 is stacked, and the lower yoke sheet 337 further has a plurality of lower cutout portions 36 formed on each of the lower magnetic sheet portions 339, wherein the upper and lower portions are missing material The portions 35 and 36 face in the same direction, so that the upper magnetic sheet portion 338 and the lower magnetic sheet portion 339 have a left-right side asymmetrical pattern as shown in FIG. 7, and the magnet ring 323 is displayed (shown in FIG. 4). The magnetic force acting on the upper magnetic sheet portion 338 and the lower magnetic sheet portion 339 forms an effect of uneven magnetic force on the left and right sides, and assists in pushing the fan wheel unit 32 (shown in FIG. 4) so that the fan wheel unit 32 is After being stopped by the external force, it can still naturally rotate again.

In summary, the external pole type heat dissipating fan of the present invention is axially wound around the circumference of the coil holder 334, so that the number of turns of the coil 335 that can be wound can be effectively increased, so as to improve the power generation due to energization. The mutually exclusive thrust increases the rotational speed of the fan unit 32, thereby improving the heat dissipation efficiency, and facilitating the winding of the coil 335 to make the production of the magnetic pole 333 easier; and the coil 335 can be energized after being energized. The lower magnetic sheet portions 338, 339 generate a radial magnetic field to push the fan wheel unit 32, which makes the external pole type heat dissipating fan have a simple overall structure and is easy to manufacture, so that the object of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

31‧‧‧Frame unit

311‧‧‧Base

312‧‧‧ center axis

32‧‧‧Fan wheel unit

321‧‧·wheels

322‧‧‧ fan leaves

323‧‧‧ magnet ring

33‧‧‧ drive unit

330‧‧‧ gap area

331‧‧‧ circuit board

332‧‧‧Inductive components

333‧‧‧ magnetic pole

334‧‧‧ coil holder

335‧‧‧ coil

336‧‧‧Upper yoke sheet

336’‧‧‧Top Board

337‧‧‧Underlying magnetic yoke

337'‧‧‧ bottom plate

338‧‧‧Upper Magnet Parts

339‧‧‧Under the magnetism department

34‧‧‧ shaft tube

35‧‧‧The Ministry of Materials

36‧‧‧Under the Ministry of Materials

1 is an exploded perspective view showing a conventional external-pole cooling fan; FIG. 2 is a plan view showing another conventional external-pole cooling fan; FIG. 3 is a plan view showing the external-pole cooling fan of the present invention. First FIG. 4 is a partial cross-sectional view, and FIG. 3 is a perspective view illustrating a magnetic pole of the first preferred embodiment; FIG. 6 is a side view illustrating the present invention. A magnetic pole in a second preferred embodiment of the pole cooling fan; and Fig. 7 is a side elevational view showing a magnetic pole in a third preferred embodiment of the outer pole cooling fan of the present invention.

31‧‧‧Frame unit

311‧‧‧Base

312‧‧‧ center axis

32‧‧‧Fan wheel unit

321‧‧·wheels

322‧‧‧ fan leaves

323‧‧‧ magnet ring

33‧‧‧ drive unit

331‧‧‧ circuit board

332‧‧‧Inductive components

334‧‧‧ coil holder

335‧‧‧ coil

336‧‧‧Upper yoke sheet

336’‧‧‧Top Board

337‧‧‧Underlying magnetic yoke

337'‧‧‧ bottom plate

338‧‧‧Upper Magnet Parts

34‧‧‧ shaft tube

Claims (6)

An external pole type cooling fan includes: a frame unit including a base and a central shaft protruding from the base; a fan unit including a hub pivoted on the central shaft, the plurality of pieces being a fan blade extending outwardly from the outer periphery of the hub, and a magnet ring disposed on the outer periphery of the blade; and a driving unit including a circuit board disposed on the base and an induction electrically connected to the circuit board An element, and a magnetic pole electrically connected to the circuit board and located outside the magnet ring, wherein the magnetic pole has a coil base located outside the magnet ring, a coil wound around a circumference of the coil base along an axial direction of the central axis, a yoke plate disposed on a top surface of the coil base, and a lower yoke plate disposed on a bottom surface of the coil base, the upper yoke plate having a top plate disposed on a top surface of the coil base a portion of the upper magnetic plate portion extending downward from a side of the top plate portion facing the magnet ring, the lower yoke piece having a bottom plate portion disposed on a bottom surface of the coil base, at least one of which cooperates with the upper portion The disk portion faces from the bottom plate portion a lower magnetic piece portion extending upward from one side of the magnet ring, wherein the upper magnetic piece portion and the lower magnetic piece portion are alternately arranged, and the upper magnetic piece portion and the lower magnetic piece portion are spaced apart from each other A gap region is formed between the upper magnetic sheet portion and the lower magnetic sheet portion. The outer-pole type heat dissipating fan according to the first aspect of the invention, wherein the upper yoke piece further has an upper material-deficient portion formed on the upper magnet piece portion, and the lower-distribution yoke piece is further Having a formed on the lower magnetic sheet portion The lower material missing portion, wherein the upper and lower material missing portions face in the same direction. The external pole type heat dissipating fan according to claim 1 or 2, further comprising a top plate portion through which the upper yoke piece is disposed, a coil base and a bottom plate portion of the lower yoke piece to combine the upper product a yoke piece, a coil base, and a shaft tube of the lower yoke piece. The external pole type cooling fan according to claim 3, wherein the sensing element of the driving unit is a Hall sensor. The external pole type heat dissipating fan according to claim 4, wherein the coil base is made of an insulating material. The external heat radiating fan according to claim 1, wherein the upper yoke sheet has a plurality of upper magnetic sheet portions extending downward from the top plate portion facing the one side of the magnet ring. The lower yoke sheet has a plurality of lower magnetic piece portions extending upward from the bottom plate portion facing the one side of the magnet ring, and the upper magnetic piece portion and the lower portion. The magnetic sheets are alternately arranged, and each of the upper magnetic sheets and the adjacent lower magnetic sheets are spaced apart from each other, so that the upper magnetic sheets and the lower magnetic portions cooperate to form a majority A gap region between the upper magnetic sheet portion and the lower magnetic sheet portion.