JP2007166787A - Flat eccentric rotor with fan, and flat brushless type vibration motor provided with rotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To cool a heating member by configuring a shaft direction gap type micro fan motor as an eccentric rotor with a fan which can generate vibration. <P>SOLUTION: A rotor is provided with a thin cup type rotor case 1 having a specific gravity of about 8 and provided with a shaft supporting portion 1a fixed with a shaft 4 on a rotary center; a dimension direction gap type magnet 2 arranged in the inside of the rotor case; and an arc-like eccentric member 3 arranged on at least the outside of the magnet. A side circumference of the rotor case is cut and opened on the opposite side via at least the rotary center of the eccentric member to form an impeller 1b, and the eccentric member is also configured having the impeller made of a tungsten with a specific gravity of about 18. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an eccentric rotor with a fan and a vibration motor with a flat brushless fan having the same rotor, and more particularly to a cooling and silent notification means.

Mobile devices such as cellular phones are becoming more and more multifunctional, and the energization time is increasing while performing intermittent functions such as the silent alarm means of this multifunctional portable communication device, resulting in a long service life. Brushless vibration motors have begun to be adopted.
Conventionally, it is a cored type as a brushless vibration motor with a built-in drive circuit member, and a drive circuit member is arranged on the side of the stator in a cored type in which armature coils are wound around a plurality of equally arranged salient poles. Things are known. (See Patent Document 1)
However, such a product has a large size in the lateral direction, has poor mounting efficiency on a printed wiring board at the time of setting, and has a large thickness due to the cored type, and is impractical.
There is also a type including a cored type and a coreless type in which a part of a plurality of armature coils is deleted to provide a space, and a drive circuit member is disposed in this space. (See Patent Document 2)
As a brushless motor, a single-phase type using a single hall sensor is common in terms of cost. However, in order to automatically start a single-phase type brushless motor, the rotor magnet is stopped at a specific position. A detent torque generating member is required.

In recent years, there has been a remarkable increase in the number of functions of mobile phones and the like, and the problem of heat generation in the stored active electronic members has been newly highlighted. In particular, in a case where there is a part that generates a considerable amount of heat locally, such as a central processing element, the local heat generation part becomes uncomfortable to the human body during operation.
In order to disperse this local heat generation, some proposals to store fixing elements for absorbing and absorbing heat such as ceramic sheets, carbon graphite sheets, heat pipes, etc. have been adopted, but only the heat absorption by such fixing elements is adopted. However, it is difficult to cope with this problem, and it is conceivable to install a fan motor that forcibly circulates air or has an air supply / exhaust function.
However, the 60 mm square axial fan motor mounted on a conventional personal computer cannot fit in size, and recently, a 20 mm square size with a heat sink in the radial direction is known. Yes. (See Patent Document 3)
In addition, a brushless fan vibration motor comprising a cored armature is long in the axial direction, and without changing the diameter of the cored rotor, the through hole is made eccentric and the rotor rotates so that air flows into the hole. A large inner rotor type that is cooled by an axially arranged centrifugal fan has been proposed. However, it is too large to be built in a mobile device such as a mobile phone, and does not match the reduction in thickness.
JP 2000-245103 A JP 2002-142427 A JP-A-9-107653 JP 2002-165406 A

Recently, it is indispensable for a cellular phone or the like to be equipped with a vibration motor as a silent alarm means, and furthermore, a space for mounting a cooling fan motor can hardly be considered in terms of design.
Accordingly, the present invention is an active micro-fan motor that is configured as an eccentric rotor with a fan so that vibration can be generated by providing an impeller using a swirling space in which an eccentric member is disposed on the rotor of the brushless motor. The heat generating member of the electronic member is intended to be cooled.

In order to solve the above-mentioned problems, a cup type rotor case provided with a shaft support portion at the center as shown in claim 1, a radial gap type magnet disposed inside the rotor case, and at least the outer side of the magnet. An arcuate eccentric member arranged in the direction, and the impeller is formed by cutting the side periphery of the rotor case on the opposite side through at least the rotation center of the eccentric member. it can.
Specifically, as shown in claims 2 and 3, the eccentric member is also made of impala, each impala is a rear-facing type, and the turning outer periphery is formed with substantially the same diameter, and the eccentric member side impala is What is formed thick in the arc direction is good.
To provide such a flat brushless fan vibration motor with the fan-equipped eccentric rotor, the fan-equipped eccentric rotor according to any one of claims 1 to 3 is housed. The eccentric rotor with a fan is driven in a housing composed of a case and a bracket, and is arranged in a cored armature coil and a space where the cored armature coil is not arranged, and supplies power to the cored armature coil. 1-hole sensor type drive circuit member is provided, and the housing is provided with an external air flow inlet and the same air flow outlet, or the housing is square in a plan view, and a part of the housing is formed in the corner. This can be achieved by using a heat sink provided with heat radiating fins.

According to invention of Claim 1, while it is a single rotor, while being able to generate a vibration at the time of rotation, ventilation can be produced with a fan. In particular, if the difference in specific gravity between the impala and the eccentric member is increased, the amount of vibration can be increased.
According to the second and third aspects of the invention, the entire circumference becomes an efficient rear-facing impala, and the air flow rate can be increased. Moreover, since the impala uses a swirling space that is a dead center on the opposite side of the eccentric member, there is no risk that the radial direction is sacrificed in size.
According to the invention of claim 4, the vibration function and the cooling function of the portable device can be obtained at the same time, and the impeller can be extended in the axial direction to increase the air flow rate.
According to the fifth aspect of the present invention, the housing having the heat radiating fins can efficiently cool the housing.

A thin cup-type rotor case having a specific gravity of about 8 with a shaft support at the center, a radial gap magnet disposed inside the rotor case, and an arc-shaped eccentric member disposed at least outward of the magnet; And the impeller is formed on the opposite side through at least the rotation center of the eccentric member to form an impala, and the eccentric member is made of tungsten having a specific gravity of about 18 and is configured as an impala. did.
FIG. 1 is a plan view of an eccentric rotor with a fan of the present invention. Example 1
FIG. 2 is a cross-sectional view of a vibration motor with a flat brushless fan incorporating the rotor of FIG.
FIG. 3 is a cross-sectional view of a main part of the modification of FIG. (Example 3)
4 is a reduced plan view of the stator portion of FIG.
Hereinafter, the configuration of the present invention will be described based on the respective embodiments shown in the drawings.

1 and 2, an eccentric rotor R with a fan includes a shallow cup-type rotor case 1 made of a thin metal plate having a specific gravity of about 4 to 8, and a radial gap-type shallow cylinder bonded to the inside of the rotor case 1. And an arcuate eccentric member 3 made of tungsten that is laser-welded T on the side periphery of the rotor case 1, and a shallow burring-shaped shaft support portion 1a is provided at the center of rotation. By doing so, the shaft 4 is attached.
Furthermore, on the opposite side of the arc-shaped eccentric member 3 of the rotor case 1, a plurality of impalas 1b are formed in a backward-facing type with respect to the rotational direction by cutting open the rotor case side periphery. A notch 1c is formed around the ceiling of the rotor case 1 of the impala 1b so that a negative pressure can be satisfactorily obtained when outside air flows.
On the other hand, both ends of the arc-shaped eccentric member 3 are formed of a push-out 3a and a pull-in 3b at both ends of the impala 1b about the turning outer periphery, and the whole is a large backward-type impala.
Therefore, since the impala 1b is formed at a position that becomes the dead center of the outer periphery of the arc-shaped eccentric member 3, the radial size is not sacrificed.

Such an eccentric rotor R with a fan is housed in a housing H composed of a case 5 and a bracket 6 constituting a motor having a diameter of about 10 mm to 12 mm and a thickness of about 3 mm to 3.4 mm, as shown in FIG. A plurality of external air flow inlets 5a are formed in the ceiling of the case 5, and an outflow port 5b for the incoming external air is provided on the side periphery. One outflow port 5b may be provided in the direction of the active electronic member to be cooled, or a plurality of outflow ports 5b may be provided to push out air in the entire circumferential direction.
Here, if there is a concern about the entry of foreign matter from the inflow port 5a, the mesh sheet m can be attached.
In this way, since each impala 1a of the eccentric rotor is formed in a backward-facing airfoil shape, as shown by an imaginary line Y, outside air is drawn in from the outside air flow inlet 5a of the ceiling portion by negative pressure and laterally by positive pressure. The air is blown out in the radial direction from the outlet 5b.
On the other hand, the bracket 6 is formed of a metal plate having a thickness of about 0.3 mm, such as a plate-like magnetic stainless steel, and a brass bearing holder 6a is attached to the center by laser welding. The bearing holder 6a is provided with a thrust washer 6b and a receiving plate 6c at the bottom, and is fitted with a bearing 6d that rotatably supports the eccentric rotor R via the shaft 4 so that the base end of the shaft 4 is pivotally supported. Yes.
The bracket 6 further has a power supply terminal mounting portion 6e extending laterally.
On the outer periphery of the bearing holder 6a on the upper surface of the bracket 6, two to four salient pole cores 7a, in which two cores are bent in the axial direction with an opening angle of 90 °, are wound through an insulating film or the like. The cored armature coil 7b is provided and is disposed on a stator base 7c made of a glass cloth epoxy substrate having a thickness of about 0.15 mm attached to the bracket 6, and a terminal of the stator base 7c is not shown, although it is not shown Is connected to the connection land in a single phase, is led out from the stator base 7c to the side, and the feed terminal portion 7d is integrated on the feed terminal mounting portion 6e to constitute the stator 7 as a whole.
The stator base 7c further includes a detent torque generating magnetic piece 6f for detecting the magnetic pole of the leakage magnetic field of the radial gap type magnet 2 arranged in the rotor R according to the number of poles of the magnet 2 to be combined. 6 is a case where there is a space below the cored armature coil 7b as a position where the salient pole core 7a is not disposed, and a one-hole sensor type drive circuit member D having a thickness of about 0.5 mm Is placed under the cored armature coil 7b. When this lower space cannot be secured, one of the cored armature coils may be deleted to secure the space, and the 1-hole sensor type drive circuit member D may be disposed here. When the Hall output is insufficient in the leakage magnetic field of the radial gap type magnet 2, the 1 Hall sensor type drive circuit member is formed in a space formed by deleting one of the cored armature coils as shown in FIG. D may be erected via the sub board 77c to receive the main magnetic field of the radial gap type magnet 2.

3 and 4 show a heat sink on the stator side.
The members equivalent to those of the above-described embodiment are denoted by the same reference numerals and the description thereof is omitted.
That is, the bracket 66, which is a part of the housing, is formed by aluminum die casting having a square shape in plan view, and a bearing holder 66a raised in the center and a groove 67 that functions as an extrusion outlet for the air flowing into the four corners of the square. A heat dissipating fin F having a wall 68 is formed, a thrust washer 6b is disposed at the bottom of the bearing holder 66a, the bearing 6d as described above is housed, and a feed terminal mounting portion 66e is formed at the side.
Here, one of the four cored armature coils 7b having an arrangement opening angle of 90 ° is deleted, and a 1-hole sensor type drive circuit member D1 is disposed on the sub-board 77c in this portion and started up. The main magnetic field of the radial magnet 2 is received.
The detent torque generating member 66f is formed of iron screws, and a plurality of detent torque generating members 66f are screwed into a relatively thick bracket 66 at an arrangement pitch in accordance with the magnetic pole opening angle (60 ° in this case) of the radial gap type magnet.
The case 55, which is the other part of the housing assembled to the bracket 66, has an external airflow inlet 55a in the ceiling, and the mounting leg 55c is suspended.
In this case 55, at least the groove 67 portion of the side radiating fin F is vacated as an external air flow outlet 55b so that air can be blown in the radial direction at a position excluding a plurality of external air flow inlets 55a and mounting legs 55c provided in the axial direction. The lower end of the mounting leg portion 55c is hooked to the locking portion 69 of the bracket 66 and assembled. This outflow port 55b may be provided at four places with heat radiation fins so that even one place can blow the air in a specific direction.
For example, if the vibration motor with a fan is mounted on a device via a heat transfer sheet such as carbon graphite, the heat generated by the active electronic component is transferred to the aluminum heat radiation fin via the heat transfer sheet. Although it comes, it will be efficiently cooled by the bracket 66 by air blowing.

As described above, the present invention can be applied to a portable small computer device such as a PDA in addition to a cellular phone.
Moreover, although the structure of this invention illustrated the thing of the axis | shaft rotation type, it is employable also as a shaft fixed type.
The stator may be a sensorless drive type.
The present invention can take various other embodiments without departing from the technical idea and characteristics thereof. Therefore, the above-described embodiment is merely an example and should not be interpreted in a limited manner. The technical scope of the present invention is indicated by the claims, and is not restricted by the text of the specification.

It is a top view of the eccentric rotor with a fan of the present invention. Example 1 It is sectional drawing of the vibration motor with a flat brushless type fan which incorporated the rotor of FIG. It is principal part sectional drawing of the modification of FIG. (Example 3) FIG. 4 is a plan view of the stator portion of FIG. 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotor case 2 Radial direction gap type magnet 3 Arc-shaped eccentric member 4 Axis 5, 55 Case
5a, 55a External airflow inlet 5b, 55b External airflow outlet 6, 66 Bracket 6a, 66a Bearing holder 7 Stator 7a Salient pole core 7b Cored armature coil 7c Stator base D, D1 1 Hall sensor type drive circuit member F Radiation fin

Claims (5)

  A cup type rotor case provided with a shaft support in the center, a radial gap type magnet arranged inside the rotor case, and an arc-shaped eccentric member arranged at least outside the magnet An eccentric rotor with a fan in which the impeller is formed by cutting a side periphery of the rotor case on the opposite side through at least the rotation center of the eccentric member.   The eccentric rotor with a fan according to claim 1, wherein the eccentric member is also made of impala.   The eccentric rotor with fan according to claim 2, wherein each impala is a rear-facing type, and a turning outer periphery is formed to have substantially the same diameter, and an eccentric member side impala is formed thick in an arc direction.   A fan housing the eccentric rotor according to any one of claims 1 to 3, wherein the fan-equipped eccentric rotor is driven by a housing formed of a case and a bracket, wherein the cored armature coil, the cored armature coil, With a flat brushless fan that is arranged in a non-placed space and is provided with a one-hole sensor type drive circuit member that supplies power to the cored armature coil, and the housing is provided with an external airflow inlet and a same outlet Vibration motor. 5. The flat brushless fan-equipped vibration motor according to claim 4, wherein the housing has a square shape in a plan view, and a part of the housing is constituted by a heat sink in which a heat radiating fin is arranged at a corner.

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