Brushless motor stator

A plurality of winding parts are wound around teeth of an iron core with insulators disposed therebetween, and a printed wiring board is electrically connected to the winding part with a plurality of terminal pins. Each terminal pin is extends along an axial direction of the iron core and is attached to one of the insulators. An end portion of each winding part is wound around one of the terminal pins, and the terminal pin is soldered to the printed wiring board together with the end portion of the winding part. The terminal pins extend through hole portions of the printed wiring board.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. National stage application claims priority under 35 U.S.C. §119(a) to Japanese Patent Application No. 2006-271837, filed in Japan on Oct. 3, 2006, the entire contents of which are hereby incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to a brushless motor stator to be used for, for example, air conditioners.

BACKGROUND ART

Conventionally, there has been a brushless motor stator having an iron core that has a plurality of teeth, winding parts wound via an insulator every teeth, and a printed wiring board that is placed on an axial end surface side of the iron core and electrically connected to the winding parts.

As shown inFIG. 5, in order to electrically connect the printed wiring board101with the winding part102, an end portion102aof the winding part102whose insulation coating had been peeled off has been wound around a lower side of a terminal pin104attached to the insulator103and soldered with preliminary solder105. Then, the tip end of the terminal pin104has been put through a hole portion101aof the printed wiring board101, and the tip end of the terminal pin104has been soldered to the printed wiring board101with solder106.

However, because of the provision of the preliminary solder105, a space107for receiving the preliminary solder105is necessary between the printed wiring board101and the insulator103, and this has led to a problem that the axial height dimension of the stator is increased.

When the brushless motor is employed in an air conditioner, the axial height dimension of the motor is restricted by the standard dimension of the air conditioner, and a reduction in the height dimension of the stator is demanded.

In order to solve the above problem, there is an example in which a terminal pin is formed in an L-like shape around which an end portion of a winding part is wound, and the L-shaped terminal pin is positioned outside the printed wiring board to restrict the axial height dimension of the stator (refer to JP 6-233505 A).

However, according to the above construction, the terminal pin has special specifications, and this leads to expensiveness in comparison with the standard terminal pin. Moreover, because of the structure in which the printed wiring board is positioned inside the terminal pin, there is a problem that it is difficult to mount the printed wiring board when the terminal pins are increased in number and the assembling workability deteriorates.

SUMMARY OF INVENTION

Technical Problem

An object of the present invention is to provide a brushless motor stator capable of improving the assembling workability while reducing the axial height dimension and suppressing the coat.

Solution to Problem

In order to solve the above problem, the brushless motor stator of the present invention comprises:

an iron core that has a plurality of teeth placed radially with respect to an axis;

a winding part wound via an insulator every teeth; and

a printed wiring board that is placed on an end surface side in an axial direction of the iron core and is electrically connected to the winding part, wherein

a terminal pin of a shape extended along the axial direction of the iron core is attached to an end surface in the axial direction of the iron core at the insulator,

one end of the terminal pin is attached to the end surface of the insulator,

an end portion of the winding part is wound around the other end of the terminal pin, and

the other end of the terminal pin and the end portion of the winding part are put through a hole portion of the printed wiring board and soldered to the printed wiring board.

With such a brushless motor stator in accordance with the present invention, the end portion of the winding part is wound around the other end of the terminal pin, and the other end of the terminal pin and the end portion of the winding part are put through the hole portion of the printed wiring board and soldered to the printed wiring board. Therefore, the terminal pin and the winding part are concurrently soldered to the printed wiring board, and this obviates the need for the (conventional) preliminary solder for soldering the winding part with the terminal pin. There is no need to provide a space for receiving the preliminary solder between the printed wiring board and the insulator, and the axial height dimension of the stator can be reduced.

Moreover, since the terminal pin has a shape extended along the axial direction of the iron core, the terminal pin is allowed to have a simple shape, and the cost can be suppressed. In addition, the printed wiring board can be mounted to the terminal pins along the axial direction of the iron core even if the terminal pins are increased in number, and the assembling workability becomes satisfactory.

Moreover, electrical connections by soldering the winding part, the terminal pin and the printed wiring board can be achieved at one time, and improvement of assembling workability and shortening of the time for the assembling work can be achieved. That is, even if the end portion of the winding part is wound around the terminal pin with the insulation coating unremoved, the winding part and the printed wiring board can be electrically connected together by melting the insulation coating by the heat of soldering.

In accordance with one aspect of the present invention, the winding part is wound around the terminal pin so as to become sparser on the inside of the hole portion of the printed wiring board than on the outside of at least one opening of the hole portion of the printed wiring board.

With such a brushless motor stator in accordance with this aspect of the present invention, the winding part is wound around the terminal pin so that the winding part becomes sparser on the inside of the hole portion of the printed wiring board than on the outside of at least one opening of the hole portion of the printed wiring board. Therefore, solder can easily enter the inside of the hole portion of the the printed wiring board and the winding part can reliably be electrically connected together.

In accordance with one aspect of the present invention, the winding part is wound around the terminal pin so as to become denser on the outside of both openings of the hole portion of the printed wiring board than on the inside of the hole portion of the printed wiring board.

With such a brushless motor stator in accordance with this aspect of the present invention, the winding part is wound around the terminal pin so as to become denser on the outside of both the openings of the hole portion of the printed wiring board than on the inside of the hole portion of the printed wiring board. Therefore, the winding part can be firmly fixed to the terminal pin.

In accordance with one aspect of the present invention, the terminal pin and the winding part are soldered to the printed wiring board with a lead-free solder.

With such a brushless motor stator in accordance with this aspect of the present invention, the terminal pin and the winding part are soldered to the printed wiring board with a lead-free solder. Therefore, the lead-free solder has a melting temperature higher than that of a solder that contains lead, and the insulation coating of the winding part can be melted more reliably by heat in the soldering process, allowing the winding part and the printed wiring board to be electrically connected together more reliably.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the brushless motor stator of the invention, the end portion of the winding part is wound around the other end of the terminal pin, and the other end of the terminal pin and the end portion of the winding part are put through the hole portion of the printed wiring board and soldered to the printed wiring board. Therefore, the assembling workability can be improved while reducing the axial height dimension and suppressing the cost.

DESCRIPTION OF EMBODIMENTS

The present invention will be described in detail below by the embodiments shown in the drawings.

FIG. 1shows a plan view of one embodiment of a brushless motor stator of the present invention, andFIG. 2shows a sectional view taken along the line A-A ofFIG. 1. The stator includes an iron core1that has a plurality of teeth11arranged radially with respect to an axis thereof, winding parts2wound via an insulator4every teeth11, and a printed wiring board3that is placed on an end surface side in an axial direction of the iron core1and electrically connected to the winding parts2.

The stator is the stator of a brushless motor for use in an air conditioner. The brushless motor is an outer rotor type motor, in which an annular rotor is placed outside the outer periphery of the stator.

The iron core1has an annular center core part10and the plurality of teeth11arranged radially outwardly on the outer peripheral surface of the core part10. The plurality of teeth11are detachably attached radially outwardly to the core part10.

The insulator4is made of, for example, resin and formed into a cylindrical shape having outer flanges41,42at both ends. One outer flange41is formed with a width larger than that of the other outer flange42.

The teeth11are constructed of, for example, a laminate steel plate and have a flange12at one end. The teeth11have the other end inserted in the insulator4from the outer flange41side at the one end and is mounted to the insulator4.

The winding part2is mounted and wound between both the flanges41,42of the insulator4. The printed wiring board3has a plurality of wires31and externally supplies electricity to each of the winding parts2via the plurality of wires31to perform UVW three-phase control of the winding parts2.

As shown inFIGS. 1 and 3, twelve insulators4are annularly arranged so that the insulators4each have the flange41located at one end positioned on the outer peripheral side and the flange42located at the other end positioned on the inner peripheral side. That is, the twelve teeth11are annularly arranged so that the flanges12of the teeth11face the outer peripheral side.FIG. 3is a plan view of the stator from which the printed wiring board3is removed.

As shown inFIGS. 1,2and3, terminal pins5of a shape extended along the axial direction of the iron core1is attached to the insulator4at an axial end surface side of the iron core1. That is, two straight terminal pins5are implanted at the end surface of the outer flange42located at the other end of each insulator4.

One end of the terminal pin5is attached to the end surface of the insulator4, and an end portion21of the winding part2is wound around the other end of the terminal pin5. The other end of the terminal pin5and the end portion21of the winding part2are put through a hole portion32of the printed wiring board3and soldered to the printed wiring board3.

As shown in the enlarged view ofFIG. 4, an electrode33constructed of a copper foil is provided on the inner surface of the hole portion32of the printed wiring board3. The winding part2is wound around the terminal pin5so as to become sparser on the inside of the hole portion32of the printed wiring board3than on the outside of at least one opening of the hole portion32. In other words, the winding part2wound around the terminal pin5on the inside of the hole portion32is sparser than the winding part2wound around the terminal pin5on the outside of the hole portion32.

Moreover, the winding part2is wound around the terminal pin5so as to become denser on the outside of both the openings of the hole portion32than on the inside of the hole portion32. In other words, the winding part2wound around the terminal pin5on the outside of the hole portion32is denser than the winding part2wound around the terminal pin5on the inside of the hole portion32.

The solder6covers part of the winding part2located on the outside of the hole portion32opposite from the insulator4and fills up the hole portion32. That is, the solder6electrically connects the end portion21of the winding part2with the electrode33of the printed wiring board3at the hole portion32. The solder6is a lead-free solder and has a melting temperature about 20° C. to 50° C. higher than that of the solder that contains lead.

In concrete, for example, an Sn—Ag—Cu type that has a melting temperature of 217 degrees or an Sn—Cu—Ni+Ge type that has a melting temperature of 227 degrees is used as the lead-free solder. It is noted that the melting temperature of the eutectic solder is 183 degrees.

Next, explaining the assembling of the stator with reference toFIGS. 1 and 4, the end portion21of the winding part2is wound around and fixed to the terminal pin5of the insulator4. At this time, the insulation coating of the winding part2is not peeled off.

Then, the printed wiring board3is moved along the axial direction of the iron core1, and the printed wiring board3is placed on the insulator4while inserting the terminal pin5, around which the end portion21of the winding part2is wound, into the hole portion32.

Subsequently, the solder6is poured to the terminal pins5from the side opposite from the insulator4with respect to the printed wiring board3, performing soldering of the terminal pin5with the printed wiring board3.

At this time, the end portion21of the winding part2is wound around the terminal pin5with the insulation coating unremoved. However, the winding part2and the printed wiring board3can be electrically connected together by melting the insulation coating by the heat of soldering. The solder6, which is the lead-free solder, has a high melting temperature and is able to reliably melt the insulation coating of the winding part2by heat.

Moreover, the winding part2is wound around the terminal pin5so as to become sparser on the inside of the hole portion32of the printed wiring board3than on the outside of the hole portion32of the printed wiring board3. Therefore, the solder6can easily enter the inside of the hole portion32of the printed wiring board3, and the electrode33provided on the inner surface of the hole portion32of the printed wiring board3and the winding part2can reliably be electrically connected together.

Moreover, the winding part2is wound around the terminal pin5so as to become denser on the outside of both the openings of the hole portion32of the printed wiring board3than on the inside of the hole portion32of the printed wiring board3. Therefore, the winding part2can be firmly fixed to the terminal pin5.

According to the brushless motor stator of the above construction, the end portion21of the winding part2is wound around the other end of the terminal pin5, and the other end of the terminal pin5and the end portion21of the winding part2are put through the hole portion32of the printed wiring board3and soldered to the printed wiring board3. Therefore, the terminal pin5and the winding part2are concurrently soldered to the printed wiring board3, and this obviates the need for the (conventional) preliminary solder for soldering the winding part2with the terminal pin5. There is no need to provide a space for receiving the preliminary solder between the printed wiring board3and the insulator4, and the axial height dimension of the stator can be reduced.

Moreover, since the terminal pin5has a shape extended along the axial direction of the iron core1, the terminal pin5is allowed to have a simple shape, and the cost can be suppressed. In addition, the printed wiring board3can be mounted to the terminal pin5along the axial direction of the iron core1even if the terminal pins5are increased in number, and the assembling workability becomes satisfactory.

Moreover, electrical connections by soldering the winding part2, the terminal pin5and the printed wiring board3can be achieved at one time, and improvement of assembling workability and shortening of the time for the assembling work can be achieved. That is, even if the end portion21of the winding part2is wound around the terminal pin5with the insulation coating unremoved, the winding part2and the printed wiring board3can be electrically connected together by melting the insulation coating by the heat of soldering.

It is noted that the invention is not limited to the above embodiment. For example, it is acceptable to apply the stator of the invention to an inner rotor type motor in which the stator is placed on the outer peripheral side and the rotor is placed on the inner peripheral side. Moreover, the teeth11, the insulators4and the terminal pins5may be freely increased or decreased in the number.