WO2005036714A1

WO2005036714A1 - Miniature motor

Info

Publication number: WO2005036714A1
Application number: PCT/JP2004/013431
Authority: WO
Inventors: Tomohide Aoyagi; Toshio Suzuki
Original assignee: Namiki Seimitsu Houseki Kabushiki Kaisha
Priority date: 2003-10-07
Filing date: 2004-09-15
Publication date: 2005-04-21
Also published as: CN1890859A; CN1890859B; KR20060064016A; JP2005117772A; KR100780837B1; TWI364903B; TW200514335A; JP4748429B2

Abstract

[PROBLEMS] A miniature motor in which the diameter and the size are reduced by preventing a failure that the bearing comes off the motor housing fitting part due to the force exerted in a thrust direction on the bearing through a drop impact, or the like, and thereby decreasing the number of components without marring the output characteristics of the miniature motor. [MEANS FOR SOLVING PROBLEMS] In the miniature motor, the magnet containing portion of the small-diameter section of the motor housing is partially provided with a step perpendicular to the rotary shaft, and the step has a magnet stop surface for holding the magnet at a noncontact position with respect to the bearing when the magnet abuts against the magnet stop surface in the thrust direction of the rotary shaft.

Description

Specification

Small motor

Technical field

The present invention relates to a coreless type small motor, and more particularly to a small motor for generating vibration having an eccentric weight attached to one end of a rotating shaft.

Background art

[0002] In recent years, in our daily life, small motors are mounted on various electronic devices, and for each device, the size, weight, and height of the motor according to the purpose are reduced. Technical development such as output has been performed.

[0003] Mobile phones, which are wireless communication devices, are also equipped with such small motors. For example, they are used in quiet public places where people gather in museums, concert halls, etc., or in business meetings or important meetings. However, when the sudden ringing of a mobile phone can be a great nuisance to other people, a small vibration-generating motor is used to notify the incoming call by vibration.

[0004] In the case of the vibration-generating small motor (hereinafter referred to as a vibration motor as necessary), a weight having an eccentricity is attached to the rotating shaft to be driven, and the eccentricity such as a weight is used when the rotor unit rotates. It uses the uneven centrifugal force of its position to oscillate to vibrate the entire mobile phone. As these mobile phones become more widespread, their mounting rate and usage frequency are increasing every day.

[0005] The small motor described in Patent Document 1 has a magnet housing portion having a small outer diameter formed at one end of a cylindrical motor housing, and a bearing and a cylindrical magnet that generates a magnetic field are provided with the small outer diameter. Are arranged and fixed together on the same surface of the magnet storage section. For this reason, the radial dimension of the small motor, which does not require the installation of a sleeve that is inserted into the center hole of the cylindrical magnet and fixes the cylindrical magnet in a predetermined position with respect to the motor housing, is reduced, and the size of the small motor is further reduced. It is a structure that can be achieved.

[0006] In addition, a resin mold body in which a metal part is replaced with resin is attached to the motor housing of the small motor described in Patent Document 2 in order to reduce the number of components and the weight of the motor. this The resin mold body has a bearing portion for supporting the rotating shaft, a sleeve portion for fixing the cylindrical magnet at a predetermined position of the motor housing, and a holding portion for preventing the resin mold body from coming off the motor housing. , Are members integrally formed of resin.

Patent Document 1: JP 2001-009372 A

Patent Document 2: JP 2001-136704 A

Disclosure of the invention

Problems to be solved by the invention

[0008] In the small-sized motor described in Patent Document 1, a cylindrical magnet is located on the same holding surface as the bearing mounted on the front end side of the storage portion having a small outer diameter, and contacts the bearing in the thrust direction. It is attached so that it faces. Therefore, when a strong force is applied to move the cylindrical magnet in the direction of the cylinder due to a drop impact or the like, the weight of the cylindrical magnet is large, and the cylindrical magnet moves, and the force of contact with the bearing and pushing is exerted. However, there is a problem when the pressed bearing deviates from the storage portion having the small outer diameter.

[0009] Further, the small motor described in Patent Document 2 has a resin mold formed integrally with the bearing even when a force is applied to the cylindrical magnet so as to move to the bearing side. The body is configured so as not to come off from the motor housing by a holding portion connecting the inside and outside of the motor housing. However, since the resin mold body is provided with a sleeve portion, it is necessary to reduce the outer diameter of the cylindrical magnet in order to further reduce the size of the motor. In this case, at the same time, the surface magnetic flux density of the cylindrical magnet is reduced, and there is a problem that the output of the small motor is reduced, which has been an obstacle to miniaturization of the motor.

[0010] The present invention has been made to solve the above-described problems, and is intended to be applied to a case where a strong force is applied to a cylindrical magnet so as to move to a thrust direction bearing side. Another object of the present invention is to provide a small motor that can prevent the bearing from deviating from the magnet housing portion force and can further reduce the diameter and size without reducing the output of the small motor. is there.

Means for solving the problem

[0011] In order to solve the above problems, in the invention described in claim 1,

One end of the stator is opened, and the other end is smaller than the one end opening diameter. A motor housing having a small-diameter portion opened to a diameter, a bearing housed in at least a small-diameter-portion-side end inner diameter of the motor housing, and rotatably supporting a rotation shaft at the center of a rotor portion; And a magnet storage portion for holding and fixing the magnet at an inner diameter near the small-diameter portion-side end of the motor housing, wherein a part of the magnet storage portion includes the magnet storage portion. A step perpendicular to the rotating shaft is formed, and the magnet abuts on the step in the rotating shaft thrust direction to hold the magnet at a non-contact position in the rotating shaft thrust direction with respect to the bearing. The motor is a small motor with a magnet stop.

That is, in a small motor in which a bearing for supporting a rotating shaft and a magnet for generating a magnetic field are provided inside a motor housing, the motor housing is provided near the small-diameter portion-side end near the motor housing. A step of a magnet housing portion having a magnet stop surface for fixing and disposing a magnet in a position not in contact with the bearing is provided.

[0013] Further, according to the invention described in claim 2, in the small motor described in claim 1,

A small motor having a magnet fixing surface that abuts the outer peripheral surface of the magnet on a part of the magnet housing in the radial direction to hold and fix the magnet at a concentric position of the motor housing.

[0014] In the invention described in claim 3, in the small motor described in claim 1 or claim 2,

The magnet housing of the motor housing is a small motor arranged at an inner diameter position different from that of the bearing housing at the inner diameter of the small diameter portion side end.

[0015] Further, according to the invention described in claim 4, in the small motor according to claim 1 to claim 3,

An eccentric weight is attached to one end of the rotor unit rotating shaft to form a vibration motor.

The invention's effect

As described above, according to the invention described in claim 1, even when a strong force is applied to a magnet having its own weight due to, for example, a drop impact, the movement of the magnet ( Magnet side (Direct force in the direction of the bearing at the end) can be completely received by the step of the magnet stop surface, so the bearing is pushed by the magnet and comes off in the thrust direction outside the end of the motor housing. Can be prevented. That is, the magnet can be firmly fixed to the motor housing, and a small motor having excellent impact resistance can be obtained.

[0017] According to the second aspect of the present invention, as the fixed structure for disposing the cylindrical magnet at the concentric position of the motor housing, the magnet housing is formed as a part of the inner diameter surface of the motor housing, that is, the small diameter of the motor housing. By forming the magnet fixing surface on the outer cylindrical portion, the outer peripheral portion of the cylindrical magnet and the magnet fixing surface having the inner diameter of the small cylindrical portion of the motor housing can be fitted and fixed. Therefore, it is not necessary to separately provide a fixing member such as a sleeve for fixing the magnet at the center position with respect to the motor housing. Therefore, even when the outer diameter of the cylindrical magnet is reduced, the inner diameter can also be reduced at the same time. There is an effect of maintaining or improving characteristics. At the same time, since it is not necessary to separately provide a fixing member such as a sleeve for fixing the magnet at the center position, the number of parts can be reduced.

According to the third aspect of the present invention, the magnet housing portion force of the motor housing is arranged at an inner diameter size position different from that of the bearing housing portion having the inner diameter at the small-diameter portion-side end portion. On the other hand, the magnet and the bearing can be individually and stably fixedly arranged.

[0019] According to the invention as set forth in claim 4, even if the vibration motor is used as a small motor having an eccentric weight attached to the rotating shaft, and the use condition is severe, the magnet is firmly attached to the motor housing. In addition, it can be stably fixedly arranged, and has the same effect as above in impact resistance.

[0020] For example, when a large force is generated in the thrust direction with respect to the rotating shaft provided with the eccentric weight due to an impact such as dropping, the eccentric weight is attached to the magnet retaining surface of the magnet housing formed in the motor housing. Even when a strong force is applied from the thrust direction magnet side to the bearing direction by being pushed by the rotating shaft, the movement and displacement of the magnet can be prevented.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a configuration of an embodiment according to the present invention will be described with reference to FIGS. In the present embodiment, a coreless type cylindrical vibration motor having an eccentric weight on the rotating shaft will be described as an example of a small motor.

FIG. 1 is a schematic sectional view showing an example of the best embodiment of the present invention. As shown in the figure, the main body of the small motor 1 has a substantially cylindrical shape having an opening at one end and a small-diameter portion that is opened through a step at the other end to a diameter smaller than the opening diameter at the one end. It consists of the formed motor housing 3. As shown in detail in FIG. 2, the motor housing 3 is provided with a housing main body 31 for housing most of the drive mechanism of the small motor 1 in FIG. 1, and one end of the housing main body 31 is shown in FIG. It is formed in a large open state. At the other end of the housing body 31, there is provided a magnet housing 32 having a smaller diameter than the housing body 31 by one step. At the end of the magnet housing 32, a magnet stop surface 32b serving as a step is provided. Are formed. Further, a bearing housing portion 33 is formed at the end of the magnet housing portion 32 so as to open with a smaller diameter than the magnet housing portion 32. As described above, the small-diameter portion-side end of the motor and the housing 3 is provided with a step in the radial direction in a stepwise manner in the shape shown in the figure.

As shown in FIG. 3, one end of a cylindrical magnet 5 for generating a magnetic field inside the motor housing 3 is housed on the inner diameter side of the magnet housing portion 32. One end of the cylindrical magnet 5 is arranged so as to abut on the magnet stop surface 32b, so that the cylindrical magnet 5 cannot move any further in the direction of the bearing housing portion 33 due to the abutment. Become.

At the same time, the outer peripheral surface of one end of the cylindrical magnet 5 is fitted on the periphery of the magnet fixing surface 32 a which is the inner peripheral surface (see FIG. 2 or FIG. 3) of the magnet housing portion 32, and the adhesive 40 It is fixed. Thus, the cylindrical magnet 5 is fixed to the motor housing 3 so that the central axis of the cylindrical magnet 5 is located on the same axis as the central axis of the motor housing 3.

On the other hand, a bearing 6 located on the front side of the output shaft is mounted on the bearing housing 33 so as to be substantially non-contact with one end surface of the cylindrical magnet 5. As shown in FIG. 1, a rotary shaft 2 serving as the central axis of the rotor penetrates through the center hole of the cylindrical magnet 5, and the rotor is rotatable by the front bearing 6 and the rear bearing 7. It is pivoted. The rear-side bearing 7 has a lid shape attached to the opening side of the housing body 31. Attached to the through hole 4a of the metal cap 4.

[0026] A part of the rotating shaft 2 is formed by molding a commutator 11 on the same axis as the rotating shaft 2, and using a coil holder 10 which is also strong. The wound coil 8 is disposed at a position facing the air gap between the 31 inner peripheral surfaces, and forms a cup-shaped mouth part.

On the other hand, a brush 9 for supplying an external current to the commutator 11 is mounted and fixed to the end cap 4 described above, and the current is supplied to the brush 9 via a power supply terminal (not shown). Supplied.

Further, in this small motor 1, a semi-cylindrical eccentric weight 12 formed of a high specific gravity sintered alloy force such as tungsten is provided at one end of a rotating shaft 2 serving as an output shaft outside a motor housing 3. It is mounted and has a structure that operates as a so-called vibration motor. In this vibration motor, when the eccentric weight 12 is rotationally driven by the rotating shaft 2, a force is generated in which the eccentric position swings, and the entire motor vibrates.

Next, the function and effect of the present embodiment will be described.

For example, when a small motor 1 (vibration motor) equipped with an eccentric weight 12 is mounted on a mobile phone, the small motor 1 operates according to the incoming call mode selection, the eccentric weight 12 rotates at high speed, and the mobile phone vibrates. Utilizing the added information, the user of the mobile phone is notified of the incoming call due to sensational vibration. Similarly, even if the small motor 1 is mounted on a controller of a game machine, a wristwatch-type alarm clock, or the like, it functions as a vibrating sensation generating device.

[0030] However, since these portable telephones or devices equipped with the vibration motor are used by being held by hand, they may be accidentally dropped. For example, when a mobile phone equipped with the small motor 1 as a vibration generator happens to drop from the side of the eccentric weight 12 to the ground or the like, a strong impact force is applied in the thrust direction. At this time, of course, a strong thrust direction force is applied to the rotating shaft 2 on which the eccentric weight 12 having a large specific gravity is attached, and the entire rotor unit is pressed strongly against the liner 20 (see FIG. 1) in contact with the cylindrical magnet 5. And Accordingly, the cylindrical magnet 5 is instantaneously subjected to a force that moves in the thrust direction on the front bearing 6 side. However, one end of the cylindrical magnet 5 is restricted by the magnet stop surface 32b from moving toward the distal end of the magnet housing portion 32, that is, in the thrust direction on the bearing 6 side. Since it is mounted in the bearing housing part 33 so as not to be in contact with one end surface of the magnet 5, even in the case of the above-mentioned accident, the strong force generated in the cylindrical magnet 5 is received by the magnet stop surface 32b. be able to. Therefore, even if the bearing 6 arranged in the bearing housing portion 33 receives the impact force on the entire motor due to the drop, the strong force in the thrust direction is not directly applied from the cylindrical magnet 5.

At the same time, the cylindrical magnet 5 is fitted on the magnet fixing surface 32a of the motor housing 3 at one end of the cylindrical outer peripheral surface thereof, and is adhered and fixed so as to be located on the same axis as the central axis of the motor housing 3. Therefore, there is no need to arrange a fixing sleeve in the center hole of the cylindrical magnet 5.

As described above, according to the present embodiment, the movement of the cylindrical magnet 5 to the thrust direction bearing 6 side is restricted by the magnet stop surface 32b, and further, the bearing 6 is connected to one end surface of the cylindrical magnet 5 By mounting the bearing 6 in the bearing housing 33 so that it is always in non-contact, the bearing 6 may lose its opening force in the bearing housing 33 due to a drop impact, etc. This prevents the force from being calored in six directions. For this reason, it is possible to provide a small motor to which a highly reliable eccentric weight is attached, which is resistant to a drop impact.

[0034] Further, since the small motor 1 does not need to include the above-described conventional sleeve, the diameter of the motor housing can be designed smaller than that of the small motor having the sleeve. In addition, since it is not necessary to provide the sleeve, the number of parts can be reduced, and the outer diameter of the small motor 1 is not changed. The inner diameter of the cylindrical magnet 5 is set small, the thickness of the cylinder is increased so that the surface magnetic flux density increases, and the cylindrical magnet 5 with a large volume can be used. There is an effect that can be.

Industrial applicability

[0035] Various types of information such as multi-functional mobile phones such as mobile phones that require a vibration function, wrist-watch type PHS, mobile small-sized wireless communication devices such as mobile phones, and mobile PDAs. Communication terminal devices, game console controllers with It is mounted on all electronic devices including electronic toys such as game machines.

Brief Description of Drawings

FIG. 1 is a cross-sectional view showing a small motor according to the present invention.

FIG. 2 is a cross-sectional view showing a motor housing portion of the small motor according to the present invention.

FIG. 3 is a cross-sectional view showing an arrangement of a motor housing of a small motor according to the present invention, bearings and cylindrical magnets.

Explanation of symbols

[0037] 1 Small motor

2 Rotary axis

3 Motor housing

31 Housing body

32 Magnet storage

32a Magnet fixing surface

32b Magnet stop

33 Bearing storage section

4 End cap

40 adhesive

5 Cylindrical magnet

6 Bearing

7 Bearing

8 Winding coil

9 Brush section

10 Coil holder

11 Commutator

12 Eccentric weight

Claims

The scope of the claims

[1] As the stator part,

A motor housing having a small-diameter portion having one end opened and the other end opened to a smaller diameter than the one-end opening diameter;

A bearing that is housed in at least the inner diameter of the motor housing at the small-diameter portion side end and that supports the rotating shaft at the center of the rotor portion;

A magnet located in the motor housing to generate a magnetic field;

A magnet housing portion for holding and fixing the magnet at an inner diameter near an end of the motor housing on the small-diameter portion side;

In a small motor comprising

A step perpendicular to the rotating shaft is formed in a part of the magnet housing portion, and the magnet abuts on the step in the thrust direction of the rotating shaft so that the magnet is opposed to the bearing.磁石 Equipped with a magnet stop surface that is held in a non-contact position in the rotating shaft thrust direction.

A small motor characterized in that:

[2] A magnet fixing surface is provided on a part of the magnet storage portion in the radial direction, the magnet fixing surface being in contact with the outer peripheral surface of the magnet to hold and fix the magnet at a concentric position of the motor housing. The small motor according to claim 1, wherein:

3. The small motor according to claim 1, wherein the magnet housing portion of the motor housing is arranged at an inner diameter position different from the bearing housing portion having the inner diameter at the end portion on the small diameter portion side.

[4] An eccentric weight is attached to one end of the rotor unit rotating shaft.

4. The small motor according to claim 3, wherein: