WO2003079520A1

WO2003079520A1 - Dc brushless motor structure and assembling method

Info

Publication number: WO2003079520A1
Application number: PCT/JP2003/003378
Authority: WO
Inventors: Hideaki Seino; Kazuya Nakamura; Shingo Suzuki
Original assignee: Namiki Seimitsu Houseki Kabushiki Kaisha
Priority date: 2002-03-20
Filing date: 2003-03-19
Publication date: 2003-09-25
Also published as: JP4099568B2; JP2003284278A

Abstract

An securing structure of the field coil of a DC brushless motor that provides an internal mounting structure in which a stabilized bonding strength is attained while rationalizing the bonding work process. The inner rotor magnet type DC brushless motor comprises a stator section housing and a rotor section magnet having a central rotary output shaft disposed oppositely through a gap as a rotary driving system in the housing on the opposite sides of a stator side field coil having a connecting part at one end, wherein a thermal adhesive sheet is interposed between the inner circumferential surface of the housing and the outer circumferential surface of the field coil, and the field coil is bonded planarly to the inner circumferential surface of the housing.

Description

Specification

DC brushless motor structure and assembly method

The present invention relates mainly to the internal structure of a micro DC brushless motor whose size is becoming smaller and smaller in diameter, and more particularly, to the fixation of a stator-side field coil in a housing. The present invention relates to a structure and an assembling method of an inner rotor magnet type DC brushless motor unit having high reliability and good assembling work efficiency. Background art

Conventionally, DC brushless motors of the inner rotor magnet type have a field coil fixedly arranged inside the stator housing inner diameter, and a magnetic field coil is penetrated around the rotary output shaft. In general, the motor is configured as a rotor part which is arranged so as to be pivotally supported at a housing center position.

For example, as shown in Fig. 8, an inner rotor section consisting of a cylindrical magnet 4 and a shaft 3 penetrating the center of the magnet is connected to the cylindrical housing 1 at both ends of the opening of the cylindrical housing 1. The bearing 2 is rotatably supported by the bearing 6 at the center of the shaft of the housing 2, and is fixedly disposed on the inner peripheral surface of the housing 1 of the magnetic material serving as the opposing yoke via the electrical insulating layer 30. The DC coil motor 110 is driven by a rotating magnetic field generated by applying a commutation current to the field coil 5 to rotationally drive the rotor unit.

The slotless DC brushless mode shown in Fig. 8 When the field coil 5 is introduced and fixed inside the housing 1, generally, when the field coil 5 is introduced into the housing 1, the gap is formed between the inner peripheral surface of the housing 1 and the outer peripheral surface of the field coil ₅ via the electric insulating layer 30. Often, the liquid adhesive is partially filled and fixed. In other words, when assembling the motor, a field coil 5 having approximately the same outer diameter is inserted into the inner peripheral surface of the cylindrical housing 1 shown in FIG. 9 in the direction of the arrow from the opening. After that, as shown in Fig. 10, the liquid adhesive 20 (including ultraviolet curing type) was inserted through the opening of the cylindrical housing 1 and the end of the field coil 5 and the housing as shown in Fig. 10 After filling and applying the liquid adhesive to the gap (space) formed in the inner diameter of the jing 1, the filling is repeated from the opening on the opposite side.The adhesive is cured, and the adhesive is cured. Conventionally, a method of fixing the field coil 5 integrally with the housing 1 at least partially has been considered as a general technique.

However, as the structure of the motor is further reduced in size and the diameter is reduced, the above-described liquid adhesive application work becomes substantially difficult. In particular, the enlarged view of the circle G in FIG. As shown in the figure, the protrusion of the liquid adhesive 20 is a problem, and it is necessary to check it with a binocular magnifier, and to perform a fine or precise work using a spatula or the like for correcting the protrusion. Not only will the assembly man-hours increase, but also the total inspection of the liquid adhesive protruding, and the partial uncuring of the liquid adhesive filled inside (of the UV curing type) In addition, there were concerns about problems with the assembly, such that a stable fixing strength could not be obtained, and further, it was a major problem that hindered automation of assembly.

In addition, a separate electric insulating layer 30 must be provided between the field coil 5 and the housing 1. Usually, the electric insulating layer 30 is coated by coating or the like. At least one of the forces to be provided, or wrapping an electrical insulating tape around the field coil to ensure electrical insulation Was kept.

The present invention solves the above problem by providing a process that replaces the conventional liquid adhesive filling in the process of assembling and fixing the field coil inside the motor. An object of the present invention is to provide a DC brushless motor that can be reliably formed, has a simple structure, and has high reliability. Disclosure of the invention

In order to achieve the above-mentioned object, in a DC brushless motor according to the present invention, a housing which is a stator portion and a magnet which is a rotor portion having a rotary output shaft disposed at the center thereof include: An inner rotor magnet type brushless motor which is opposed to the stator side field coil having a connection part at one end with a gap as a rotary drive system disposed inside the housing with a stator side field coil interposed therebetween, A structure in which a heat bonding sheet is interposed between the inner peripheral surface of the housing and the outer peripheral surface of the field coil, and the field coil is fixed to the inner peripheral surface of the housing in a planar manner. And then.

According to this invention, even in the case of an inner rotor magnet type DC brushless motor having a small outer diameter, it is necessary to perform the filling and application of the liquid adhesive twice from both ends of the nozzle opening. In addition, the adhesive does not protrude, so that there is no need for any repair work, and the bonding process between the field coil and the housing can be simplified, thereby improving work efficiency. Further, since the field coil is fixed in a planar manner with respect to the inner diameter of the housing, the fixing strength is stable, the axial inclination of the field coil is small, and the axis deviation from the housing is small.

Further, the inner rotor magnet type DC brushless according to the present invention is provided. In the motor, in addition to the above, the heat bonding sheet is composed of a heat-active synthetic rubber-based bonding layer, has a multilayer structure in which a nonwoven fabric is sandwiched between intermediate layers, and the nonwoven fabric layer is electrically insulated. It has a property.

According to this invention, the electric insulation between the field coil and the housing is further ensured by sandwiching the electrically insulating nonwoven fabric in the intermediate layer of the thermally active synthetic rubber-based adhesive layer. In other words, by using an integrated thermal bonding sheet having both the effect of the conventional electrical insulating layer and the bonding effect of the liquid adhesive, the liquid adhesive does not protrude, so There is no work loss in the step of wiping the outlet, etc., and the thickness of the thermal adhesive sheet is uniform and the surface contact can be ensured.Therefore, there is no variation in adhesive strength. Therefore, the reliability of both the electrical insulation between the field coil and the housing and the fixation between the field coil and the nozing are greatly improved. Further, the step of winding the electric insulating layer in the conventional process is not required.

Further, in the inner rotor magnet type DC brushless motor according to the present invention, the heat bonding sheet includes a heat-active synthetic rubber bonding layer, and The layer is made of an adhesive component containing no organic solvent.

In this way, unlike the conventional solvent-containing liquid adhesive, the heat-bonded sheet does not contain an organic solvent in the step of fixing the field coil and the nozing, so that it can be assembled in a sanitary environment. Work can be performed, and work can be streamlined and pollution-free.

Also, in the inner rotor magnet type DC brushless motor according to the present invention, a substantially circular shape for holding a flexible board for connecting the field coil connection portion to an external power supply. An annular fixed substrate is arranged and fixed at one end of the field coil on the side of the drawn-out connection portion, and A concave groove for adhering and holding the field coil lead-out connection portion is formed around the fixed substrate.

As a result, the work of connecting, assembling, and assembling the small cylindrical field coil part, whose diameter will be further reduced in the future, can be easily performed, and the fixed substrate draws out the field coil. Since it functions as a connection relay point for holding the connection part and connecting to the flexible board, there is no fear of disconnection, and the connection work with an external power supply can be easily performed.

Also, in the inner rotor magnet type DC plus motor according to the present invention, a step of winding a heat bonding sheet around an outer peripheral surface of a field coil having a connection portion at one end; A step of inserting the field coil around which the coil is wound into the inside diameter of the housing, and a heat treatment step of heating the inserted heat bonding sheet to bond and cure the bonding layer, whereby the field coil is placed in the housing. A series of assembling methods that adhere to the surface are adopted.

As a result, it is possible to streamline the fixing work process and improve the process, to always obtain a stable, non-polluting, work-efficient and stable fixing strength. , Deformation, etc. can be prevented. In addition, the adhesive does not adhere to or protrude from portions other than the adherend, and there is no work loss.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a side sectional view showing an example of a DC brushless motor according to an embodiment of the present invention.

FIG. 2 is a sectional side view showing an example of an internal configuration of a field coil mounting of the DC brushless motor according to the embodiment of the present invention.

FIG. 3 is a perspective view of a DC brushless motor according to an embodiment of the present invention. FIG. 3 is a perspective view showing the winding shape of a wound coil type field coil and a heat bonding sheet.

FIG. 4 is a perspective view showing a sectional shape of a field coil of the DC brushless motor according to the embodiment of the present invention.

FIG. 5 is a perspective view showing a process of assembling the stator according to the embodiment of the present invention.

FIG. 6 is a side sectional view showing an example of an internal structure of a heating jig base used in a heat curing step of a heat bonding sheet of the DC brushless motor according to the embodiment of the present invention.

FIG. 7 is a side sectional view showing an example of the internal structure of a heat-bonded sheet of the DC brushless motor according to the embodiment of the present invention.

FIG. 8 is a sectional side view showing an example of a conventional DC brushless motor. Fig. 9 is a cross-sectional side view showing an example of the internal configuration of mounting a field coil of a conventional DC brushless motor.

FIG. 10 is a perspective view showing an example of applying a liquid adhesive when a field coil is attached to a conventional DC brushless motor.

FIG. 11 is a perspective view showing the shape of a toroidal field coil of a DC brushless motor according to an embodiment of the present invention. Best form to carry out the invention

Hereinafter, preferred embodiments of a DC brushless motor structure according to the present invention will be described in detail with reference to the drawings. It should be noted that the present invention is not limited to this embodiment, and the detailed structure is an example.

FIG. 1 is a sectional side view showing a configuration of an inner rotor magnet type DC brushless motor 11 having an outer diameter of 10 mm according to an embodiment of the present invention. It is an example of a figure. In this structure, the basic component configuration is almost the same as the conventional example, and the cylindrical magnet 4 and the shaft penetrating the center

3 is rotatably supported by a bearing 6 at a shaft center position of a flange 2 located at a side end opening of a cylindrical housing 1. Cylindrical field coil fixedly arranged on one side of fixed substrate 9 molded with resinable mold and resin

5 is a DC brushless motor that generates a rotating magnetic field by energizing commutation through a flexible substrate 7 to rotate the rotor unit. In the case of this motor, the rotor-section cylindrical magnet 4 and the stator-section cylindrical housing 1 are, for example, obliquely wound-type cylindrical field coils 5 shown in FIG. A common so-called tortoiseshell-shaped cylindrical field coil 5 '(see Fig. 11) is interposed between the motor housing inside and outside with a gap as a drive system inside.

Here, structurally, the point different from the conventional example in FIG. 1 of the present invention is a fixing structure of the field coil 5 and the housing 1 in the stator portion. That is, a thin synthetic rubber-based heat-adhesive curable resin material is provided between the inner peripheral surface of the housing 1 as shown in FIG. 1 and the outer peripheral surface of the cylindrical field coil 5. The point is that the field coil 5 is fixed to the inner peripheral surface of the housing 1 via the heat bonding sheet 10.

The thermal bonding sheet 10 used here has a multilayer structure in which a non-woven fabric 14 is included in a part of the sheet shape and is sandwiched as an intermediate layer, as shown in FIG. 7, for example. In addition, the 14 non-woven fabric layers have electrical insulation properties. Further, 13 layers of the heat-active synthetic rubber adhesive are formed in two layers on both sides so as to sandwich the nonwoven fabric 14. The synthetic rubber-based adhesive layer contains no solvent. 03 03378

8 In consideration of the working environment, they are pollution-free.

This heat-bonded sheet has a thickness of about 0.1 mm, is uniform, can be cured in a relatively low temperature and in a short time, and is slightly smaller than the outer circumference of the field coil. The pre-cut tape-shaped thermal adhesive sheet may be stuck, then inserted into the housing, and the thermal adhesive sheet adhesive portion or the adhesive may be effectively heated as a whole. As specific heating conditions, a heating temperature of 100 to 120 ° C. and a holding time of 3 to 5 minutes are sufficient, and the treatment is simple.

As an assembly operation procedure, first, using the heat bonding sheet 10, the width of the axis of the field coil 5 is set on the outer peripheral surface of the cylindrical field coil 5 shown in FIG. A band-like heat-bonded sheet 10 cut slightly shorter than the dimension in the direction is evenly wound, and the state as shown in Fig. 3 (b) is obtained. At this time, the seam of the heat bonding sheet 10 is preferably formed so as not to overlap.

Next, in FIG. 4, a substantially circular ring holding a flexible board 7 for connecting to an external power supply to which a connection portion 8 disposed at the connection portion side end of the field coil 5 is connected. The flexible substrate 7 and the connection portion 8 are connected by soldering or spot welding via the fixed substrate 9. At this time, the field coil connection part 8 is fixed with an adhesive to the concave groove formed on the side surface of the fixed substrate 9 as shown in the enlarged view E of the circular frame shown in FIG. Have been. Normally, in the case of a small motor of this kind, the fixed substrate 9 may be integrally formed on one surface of the flexible substrate 7 with a resin mold, or may be formed separately and fixed later by bonding or the like.

Next, as shown in FIG. 4, the assembled material 41 composed of a plurality of parts is peeled off the separator 12 (see FIG. 7) on the outer surface of the heat-bonded sheet 10, and then the fifth material is removed. As shown in the figure, the housing'1 Then, as shown in FIG. 6, the housing 1 and the field coil 5 are positioned and set on a heating jig base 100 as shown in FIG.

At this time, the position of the field coil 5 relative to the housing 1 is controlled by the height D shown in FIG. In addition, the required radial dimension position of the field coil 5 is regulated by the outer diameter surface 100a of the jig base 100, and the eccentricity error to the center position is accurately and simultaneously positioned with the thermal bonding. Is done. While maintaining the state shown in FIG. 6, heating is performed by a heater 101 built in the jig table 100 to perform a heat-adhesive curing treatment.

The conditions for this heat treatment curing were a heating temperature of 120 ° C and a holding time of 3 minutes at the bonding point. The conditions are set as appropriate according to differences in the motor's component composition, materials, and dimensions. In addition, heat treatment is performed by using a jig table of the same shape instead of using the jig table 100 with a built-in heater on the production line, and then performing heat treatment in batches in a batch-type constant temperature bath. Is also good.

The stator-side assembled members 21 bonded together by the heat treatment are heat-bonded from the cylindrical end faces of the field coil 5 as shown in the enlarged view F of the circular frame in FIG. A uniform, well-finished, and firm bond can be achieved on a mass production basis in the process without any protruding layers.

An inner rotor section consisting of a cylindrical magnet 4 and a shaft 3 penetrating the center of the inner magnet 21 is placed on this member 21 at the side end opening of the cylindrical housing 1 shown in Fig. 1. The DC brushless motor for the purpose of the present invention is completed by being rotatably supported by the bearing 6 at the shaft center position of the flange 2 to be rotated.

As described above, according to the present invention, the step of winding the heat bonding sheet 10 around the outer peripheral surface of the cylindrical field coil 5 having the connection portion 8 in which the fixed substrate 9 is incorporated, Wound monolithic field coil A step of inserting the hole 5 into the inner diameter of the cylindrical housing 1, and a heat treatment step of heating the sandwiched portion of the heat-bonding sheet 10 to bond and harden the heat-bonding layer. A DC brushless motor field coil assembling method for easily fixing the magnetic coil 5 to the housing 1 of the motor is employed.

This eliminates the need for conventional liquid adhesive to fill the gap between the field coil and the housing inner diameter (space), which simplifies the process and further reduces the outer diameter. Even with an inner rotor magnet type DC brushless motor, the air gap between the rotor magnet and the inner diameter of the rotor coil is uniform because the field coil uniformly contacts the inner diameter of the housing and the inner diameter of the housing. Can be managed stably, and as a result, the effect on the performance of the motor can be expected to be improved.

FIG. 11 is a perspective view showing a field coil having a winding shape different from the obliquely wound forming field coil 5 shown in the above embodiment. It can be applied to the magnetic coil 5 '.

As described above, the series of structures has been described with respect to the cylindrical DC brushless motor having an outer diameter of 10 mm as an embodiment of the present invention. Is not limited to this. In addition, the present invention can be appropriately applied to a motor having a drive form different from that of the present embodiment and an inner rotor magnet net type DC brushless motor having a smaller outer diameter of 10 mm or less. It goes without saying. Industrial applicability

As described above, in the DC brushless motor according to the present invention, the inner rotor magnet type DC brushless motor having a small outer diameter is provided. 3378

Even if it is a material, it is not necessary to apply and apply the liquid adhesive twice from both ends of the conventional housing opening, so that the adhesive does not protrude and no correction work is required. In addition, the bonding process between the field coil and the housing can be simplified, and the work efficiency is improved by reducing the number of steps. In addition, since the field coil is fixed in a planar manner with respect to the housing inner diameter, the fixing strength is stable, the inclination of the field coil in the axial direction is small, and the axis deviation from the housing is small. .

Further, in the inner rotor magnet type DC brushless motor according to the present invention, an electrically insulating nonwoven fabric is sandwiched between the intermediate layers of the thermally active synthetic rubber adhesive layer. The electric insulation between the field coil and the housing is more reliable, and the use of an integrated thermal bonding sheet that combines the effect of the conventional electric insulating layer with the bonding effect of the liquid adhesive is achieved. As a result, the liquid adhesive does not protrude, so there is no work loss such as a step of wiping off the protruding portion, and the thickness of the heat bonding sheet is uniform, and the surface is surely secured. Since the contact is possible, there is no variation in the adhesive strength, and thus the reliability of both the electrical insulation between the field coil and the housing and the reliability of the adhesion between the housing and the housing are dramatically improved. You. Further, the step of winding the electric insulating layer in the conventional process is not required.

Also, in the inner rotor magnet type DC brushless motor according to the present invention, in the fixing step of the field coil and the housing, the conventional solvent-containing liquid adhesive is different from the conventional solvent-containing liquid adhesive. On the contrary, since the heat bonding sheet does not contain an organic solvent, the assembling work can be performed in a sanitary environment, and the work can be streamlined and the pollution can be reduced.

Further, in the inner rotor magnet type DC brushless motor according to the present invention, the connection, assembling, and assembling operations of the small cylindrical field coil portion, which has a smaller diameter, will be easily performed in the future. Can be performed, and 03378

1 2 The board functions as a relay point for connecting the field coil to the flexible board, so that there is no fear of disconnection, and the board can be connected to an external power supply. Can be easily connected.

Further, in assembling the inner rotor magnet type DC brushless motor according to the present invention, the fixing work process can be rationalized and the process can be improved, and the stable fixing strength with no pollution and good work efficiency can be achieved. , And can be prevented from falling off or deforming due to aging as compared with conventional partial bonding. In addition, the adhesive does not adhere to or protrude from portions other than the adherend, and there is no work loss.

Claims

Range of 5W demand

1. The stator housing and the rotor magnet with the rotary output shaft arranged at the center are connected to the rotary drive system inside the housing with the stator side field coil having a connection at one end. And a brushless motor of an inner rotor magnet type arranged to face each other with a gap between the inner circumferential surface of the housing and the outer circumferential surface of the field coil. A DC brushless motor characterized in that the field coil is fixed to the inner peripheral surface of the housing in a planar manner through a heat bonding sheet.

2. The heat-bonding sheet is composed of a heat-active synthetic rubber-based bonding layer, has a multi-layer structure in which a non-woven fabric is sandwiched between intermediate layers, and the non-woven fabric layer has electrical insulation properties. The DC brushless motor according to claim 1.

3. The thermal adhesive sheet is made of a heat-active synthetic rubber-based adhesive layer, and the synthetic rubber-based adhesive layer is made of an adhesive component containing no organic solvent. Or the DC brushless motor according to claim 2.

4. A substantially annular fixed board for holding a flexible board for connecting the field coil connection to an external power supply is attached to one end of the field coil on the side of the drawing connection. 4. The DC brush according to claim 1, wherein a concave groove is formed around the fixed substrate for adhering and holding the field coil lead-out connection part around the fixed substrate. Less motor.

5. A step of winding a heat bonding sheet around the outer peripheral surface of the field coil having a connection portion at an end, and a step of winding the field coil having the heat bonding sheet wound thereon. Fixing the field coil in the housing by a step of inserting into the housing inner diameter, and a heat treatment step of heating the inserted heat bonding sheet to bond and cure the bonding layer. The method for assembling a field coil for a DC brushless motor according to claim 1 to claim 4.