Patent Description:
Conventionally, a molded motor in which a stator is covered with a mold resin is known (Patent Literature <NUM> (PTL <NUM>)). For example, a molded motor includes a stator, a rotor disposed inside the stator, a mold resin that covers the stator, and a printed circuit board to which coils included in the stator are connected. In a molded motor, a plurality of lead wires connected to a printed circuit board are drawn out of the motor via a lead bush attached to an opening of a side wall portion made of a mold resin. Another example of such a motor is disclosed in <CIT>.

In recent years, as the output of molded motors has increased, the heat generated by the coils wound around the stator core has increased. Thus, there is a problem that the mold resin covering the coils is thermally deteriorated.

Therefore, in order to suppress heat deterioration of the mold resin, it has been proposed to use an epoxy resin in which fillers having a high thermal conductivity are contained as a mold resin (Patent Literature <NUM> (PTL <NUM>)). Citation List.

However, when a coil abnormally heats up by an excessive amount of current flowing in the coil included in the stator or the like, there is a possibility that a layer short circuit may occur in which the insulating material that insulates and coats the surface of the conductive wire forming the coil is melted and the conductive wires forming the coil are short-circuited. In addition, sparks may occur when a layer short circuit occurs.

In this case, if the coil is disconnected, no current will flow through the coil, so that abnormal heat generation of the coil can be avoided. However, in a high-output molded motor, the wire diameter of the coil included in the stator is large (for example, φ0. <NUM> or more), so that the coil is less likely to be disconnected even if the coil abnormally heats up. For this reason, there is a high possibility that a layer short circuit will occur in a high-output molded motor.

On the other hand, when the temperature of the interior of the motor is increased due to heat generation of the coil or the like, flammable gas is generated from the resin components such as an insulator interposed between the lead bush or the stator core and the coil.

In this way, if a layer short circuit occurs and sparks are generated when flammable gas is present inside the motor, the sparks may ignite the gas.

Particularly, when the flammable gas is generated in the vicinity of the lead bush, the spark is likely to occur between the lead wires which are inserted through the lead bush due to the air (oxygen) flowing in the vicinity of the lead bush, and the possibility to ignite increases.

At this time, if the lead bush is made of resin, the lead bush will melt due to ignition. For example, a lead bush made of polybutylene terephthalate (hereinafter referred to as "PBT") starts to melt at about <NUM>. When the lead bush is melted in this way, there is a possibility that the ignited fire will spout from the melted portion of the lead bush (that is, the opening of the side wall portion formed by the mold resin) to the outside of the motor to spread the fire.

In addition, when the temperature inside the motor continues to be high, the combustible gas is filled inside the motor and the concentration (pressure) of the gas increases, so that the possibility for an ignited fire to spout to the outside increases. At this time, a fire is likely to spout to the outside from the lead bush, which is weaker in strength than the mold resin.

The present disclosure has been made in order to solve such a problem, and an object of the present disclosure is to provide a molded motor that can suppress fire from spouting from the place where the lead bush in the mold resin is attached even when ignition occurs inside the mold resin due to abnormal heat generation or the like of the coil included in the stator.

To achieve the above object, one aspect of the molded motor according to the present disclosure includes: a stator that includes a stator core and a coil wound around the stator core via an insulator; a rotor that is arranged to face the stator and includes a rotor core and a rotary shaft; a mold resin that includes a first opening and covers the stator; and a lead bush that is attached to the first opening and includes an insertion through-hole for drawing out an electric wire, wherein the lead bush includes a metal member including a second opening for drawing out the electric wire, the second opening being smaller than the first opening and larger than the insertion through-hole.

In addition, another aspect of the molded motor according to the present disclosure includes: a stator that includes a stator core and a coil wound around the stator core via an insulator; a rotor that is arranged to face the stator and includes a rotor core and a rotary shaft; a mold resin that includes a first opening and covers the stator; and a lead bush made of a ceramic that is attached to the first opening and has an insertion through-hole for drawing out an electric wire, wherein the insertion through-hole is smaller than the first opening.

According to the present disclosure, even when the fire occurs inside the mold resin, it is possible to suppress fire from spouting to the outside from the portion where the lead bush in the mold resin is attached.

Hereinafter, embodiments of the present disclosure will be described. It should be noted that each of the embodiments described below shows a specific example of the present disclosure. Therefore, the numerical values, the components, the arrangement positions and connection forms of the components, the steps, the order of the steps, and the like shown in the following embodiments are examples, and are not intended to limit the present disclosure. Therefore, among the components in the following embodiments, the components that are not described in the independent claims showing the highest concept of the present disclosure will be described as arbitrary components.

In addition, each drawing is a schematic view and is not necessarily strictly illustrated. It should be noted that in each drawing, the same reference numerals are given to substantially the same configurations, and overlapping description will be omitted or simplified.

First, the overall structure of molded motor <NUM> according to Embodiment <NUM> will be described with reference to <FIG>. <FIG> is a perspective view of molded motor <NUM> according to Embodiment <NUM>. <FIG> is an exploded perspective view of molded motor <NUM>. <FIG> is a cross-sectional view of molded motor <NUM>. <FIG> is a cross-sectional view of molded motor <NUM> taken along line IV-IV in FIG. It should be noted that in <FIG>, a direction in which rotary shaft <NUM> included in rotor <NUM> extends is defined as axial direction X, a direction that extends from shaft center C about shaft center C of rotary shaft <NUM> is defined as radial direction Y, and a circumferential direction centered on shaft center C is defined as circumferential direction Z. In addition, in <FIG>, hatching is omitted for convenience of illustration of the core portion of stator core <NUM> and the core portion of rotor core <NUM> in order to make the drawing easy to see.

As shown in <FIG>, molded motor <NUM> includes stator <NUM>, rotor <NUM> arranged to face stator <NUM>, mold resin <NUM> covering stator <NUM>, and lead bush <NUM> attached to mold resin <NUM>.

Molded motor <NUM> further includes first bearing <NUM> and second bearing <NUM>, first bracket <NUM> and second bracket <NUM>, first metal cover <NUM> and second metal cover <NUM>, and circuit board <NUM>.

In molded motor <NUM>, mold resin <NUM>, first bracket <NUM>, second bracket <NUM>, and first metal cover <NUM> configure the outer shell of molded motor <NUM>.

Molded motor <NUM> in the present embodiment is a brushless motor without using a brush. In addition, molded motor <NUM> in the present embodiment is an inner rotor type motor in which rotor <NUM> is arranged inside stator <NUM>. It should be noted that the present disclosure can also be applied to an outer rotor type motor in which the rotor is arranged outside the stator.

Stator <NUM> (stational element) is arranged so as to surround rotor <NUM> via a small air gap between stator <NUM> and rotor <NUM>. Stator <NUM> includes stator core <NUM>, coil <NUM>, and insulator <NUM>.

Stator core <NUM> is an annular iron core that generates a magnetic force for rotating rotor <NUM>. As shown in <FIG>, stator core <NUM> is, for example, a stacked body in which a plurality of electromagnetic steel plates are stacked in the longitudinal direction (axial direction X) of rotary shaft <NUM> included in rotor <NUM>. It should be noted that stator core <NUM> is not limited to the stacked body and may be a bulk body made of a magnetic material.

As shown in <FIG>, stator core <NUM> includes yoke 11a formed in an annular shape so as to surround rotor <NUM>, and a plurality of teeth 11b protruding from yoke 11a toward rotary shaft <NUM> in a convex shape. In the present embodiment, stator core <NUM> is provided with twelve teeth 11b.

Yoke 11a is a back yoke formed outside each tooth 11b. In the present embodiment, yoke 11a is formed in an annular shape about shaft center C.

The plurality of teeth 11b are arranged at equal intervals in circumferential direction Z, respectively, while forming slots <NUM> which are openings between them. In addition, extending portions 11b1 extending on both sides in circumferential direction Z are formed at the extending tip portions where each tooth 11b is extended. The inner peripheral surface located at the tip portion of tooth 11b including this extending portion 11b1 serves as a magnetic pole surface facing the outer peripheral surface of rotor <NUM>. It should be noted that in two adjacent teeth 11b, a gap (slot opening) exists between extending portion 11b1 of one tooth 11b and extending portion 11b1 of the other tooth 11b.

Coil <NUM> is a winding coil wound around stator core <NUM> via insulator <NUM>. Specifically, as shown in <FIG>, coil <NUM> is wound around each of the plurality of teeth 11b included in stator core <NUM>. In addition, as shown in <FIG>, each coil <NUM> includes coil end 12a protruding from stator core <NUM> to both sides of stator core <NUM> along the longitudinal direction (axial direction X) of rotary shaft <NUM>. That is, coil end 12a is a portion of coil <NUM> that protrudes and sticks out from stator core <NUM> in axial direction X. It should be noted that <NUM> coils <NUM> are used in the present embodiment. Therefore, the number of slots of molded motor <NUM> is <NUM>.

In addition, molded motor <NUM> is a high output motor having an output of <NUM> W or more in the present embodiment. For this reason, coil <NUM> having a wire diameter φ of <NUM> or more is used. As an example, wire diameter φ of coil <NUM> is <NUM> to <NUM>.

The plurality of coils <NUM> are configured by each unit coil of three phases of U phase, V phase, and W phase whose phases are electrically different from each other by <NUM> degrees. That is, each coil <NUM> wound around tooth 11b is energized and driven by three-phase alternating current that is energized in units of U-phase, V-phase, and W-phase, respectively. It should be noted that coils <NUM> of each phase are connected by a crossover wire (not shown). The crossover wire is arranged on the outer peripheral wall portion of insulator <NUM> or the like. Coil <NUM> and the crossover wire are configured by a conductor wire serving as a core wire and an insulator for insulating and coating the surface of the conductor wire.

In addition, ends of each phase of coil <NUM> are connected by winding connection portions included in circuit board <NUM>. Specifically, pattern wirings for electrically connecting the plurality of coils <NUM> for each of the U-phase, V-phase, and W-phase are formed on circuit board <NUM>, and the ends of coils <NUM> for each phase are electrically connected with pattern wirings of circuit board <NUM> by solder or the like. It should be noted that circuit board <NUM> includes an opening through which rotary shaft <NUM> is loosely inserted at a center portion, and has, for example, an annular shape (a donut shape), a fan shape (an arc shape), a C shape, or the like.

Alternatively, the terminal of each phase of coil <NUM> may be configured to use a connecting member made of a conductive material in addition to the configuration using the circuit board. It should be noted that the present disclosure can be applied to any structure as long as the lead wire is inserted inside the enclosure of the motor regardless of the specifications of the motor.

As shown in <FIG> and <FIG>, insulator <NUM> is an insulating frame that covers stator core <NUM>. Specifically, insulator <NUM> covers teeth 11b included in stator core <NUM>, and is provided for each tooth 11b. Insulator <NUM> is made of, for example, an insulating resin material such as PBT.

Rotor <NUM> (rotational element) arranged inside stator <NUM> rotates due to the magnetic force generated in stator <NUM>. Specifically, rotor <NUM> includes rotary shaft <NUM>, and rotates about shaft center C of rotary shaft <NUM> as a rotation center. Rotary shaft <NUM> extends along axial direction X.

Rotor <NUM> has a configuration in which a plurality of N poles and S poles are repeatedly present in circumferential direction Z. In the present embodiment, rotor <NUM> is a permanent magnet embedded rotor (IPM rotor), and includes rotor core (rotational element iron core) <NUM> and permanent magnet <NUM> that is inserted into each of a plurality of magnet insertion holes <NUM> formed in rotor core <NUM>.

As shown in <FIG>, rotor core <NUM> is a substantially columnar stacked body in which a plurality of electromagnetic steel plates are stacked in the longitudinal direction (axial direction X) of rotary shaft <NUM>. In addition, rotor core <NUM> is formed with a plurality of magnet insertion holes 22a penetrating in axial direction X at equal intervals in circumferential direction Z as shown in <FIG>. One permanent magnet <NUM> is inserted into each magnet insertion hole 22a. In the present embodiment, the number of magnetic poles is <NUM>, and ten permanent magnets <NUM> are arranged so that the S-pole and N-pole are alternately located in circumferential direction Z.

Rotary shaft <NUM> is fixed to the center of rotor core <NUM>. Rotary shaft <NUM> is a shaft such as a metal rod, and penetrates rotor core <NUM> so as to extend on both sides of rotor core <NUM>. Rotary shaft <NUM> is fixed to rotor core <NUM> by, for example, being press-fitted or shrink-fitted into a center hole of rotor core <NUM>.

As shown in <FIG>, rotary shaft <NUM> is held by first bearing <NUM> and second bearing <NUM>. With this, rotor <NUM> is rotatable with respect to stator <NUM>. As an example, first bearing <NUM> and second bearing <NUM> are bearings that rotatably support rotary shaft <NUM>. First bearing <NUM> is fixed to first bracket <NUM> made of a metal. In addition, second bearing <NUM> is fixed to second bracket <NUM> made of a metal. It should be noted that rotary shaft <NUM> penetrates first bearing <NUM>, and although not shown, a load such as a rotary fan is attached to a portion of rotary shaft <NUM> that protrudes from first bearing <NUM> to the outside. A portion of rotary shaft <NUM> to which a load such as a rotary fan is attached is also referred to as output shaft 21a.

Rotor <NUM> configured in this way is rotated by the magnetic flux generated in stator <NUM>. Specifically, when electric power is supplied from circuit board <NUM> to coil <NUM> included in stator <NUM>, a field current flows through coil <NUM> and a magnetic flux is generated in stator core <NUM>. The magnetic force generated by the interaction between the magnetic flux generated by this stator core <NUM> and the magnetic flux generated by permanent magnet <NUM> included in rotor <NUM> serves as a torque for rotating rotor <NUM>, and rotor <NUM> rotates.

As shown in <FIG>, stator <NUM> is covered with mold resin <NUM>. Specifically, mold resin <NUM> covers stator core <NUM>, coil <NUM>, and insulator <NUM> except for the inner peripheral surface of teeth 11b included in stator core <NUM>. Mold resin <NUM> is made of a resin material such as unsaturated polyester (BMC).

In the present embodiment, mold resin <NUM> configures an enclosure which is a part of the outer shell of molded motor <NUM>. That is, mold resin <NUM> that covers stator <NUM> configures a housing that encloses rotor <NUM>. Specifically, mold resin <NUM> is a body portion of molded motor <NUM> and is formed in a substantially cylindrical shape.

It should be noted that first bracket <NUM> is provided on one edge portion of mold resin <NUM> so as to close one opening of mold resin <NUM>. In addition, second bracket <NUM> is provided on the other edge portion of mold resin <NUM> so as to close the other opening of mold resin <NUM>. First bracket <NUM> and second bracket <NUM> are made of, for example, iron, but are not limited thereto. In addition, the overall diameter of first bracket <NUM> is smaller than the overall diameter of second bracket <NUM> in the present embodiment, but the present invention is not limited thereto.

As shown in <FIG>, lead bush <NUM> is attached to mold resin <NUM>. Here, detailed configurations of mold resin <NUM> and lead bush <NUM> will be described using <FIG> with reference to <FIG>.

<FIG> is a diagram showing molded motor <NUM> according to Embodiment <NUM> with lead bush <NUM> removed. <FIG> is a diagram showing a state in which lead bush <NUM> is attached to mold resin <NUM>. It should be noted that the vertical direction (axial direction X) of molded motor <NUM> in <FIG> is shown in reverse to <FIG> and <FIG> in order to make it easier to understand how lead bush <NUM> is attached to mold resin <NUM>.

<FIG> is a diagram showing the configuration of lead bush <NUM> used in molded motor <NUM>, wherein (a) is a front view, (b) is a side view, and (c) is a top view. It should be noted that metal member <NUM> is hatched for convenience in <FIG>. In addition, (b) in <FIG> shows a cross-section of metal member <NUM> taken along line B-B of (a) in <FIG>, and (c) in <FIG> shows a cross-section of metal member <NUM> taken along line C-C of (b) in <FIG>. In addition, <FIG> is a cross-sectional view showing a peripheral structure of mold resin <NUM> and lead bush <NUM> in molded motor <NUM>.

As shown in <FIG> and <FIG>, mold resin <NUM> includes first opening 30a. Lead bush <NUM> is attached to this first opening 30a. As shown in <FIG>, first opening 30a is formed so as to cut out a part of the outer wall portion of mold resin <NUM>. Specifically, first opening 30a is formed so as to cut out a part of the opening end portion of mold resin <NUM> along shaft center C. As an example, the shape of first opening 30a is a rectangular shape in a side view of mold resin <NUM>. Lead bush <NUM> is attached to mold resin <NUM> by inserting it into this first opening 30a along shaft center C. Specifically, lead bush <NUM> is provided with recess 40b for accommodating the side wall portion of mold resin <NUM> as shown in <FIG> and <FIG>, and lead bush <NUM> can be fixed to mold resin <NUM> by fitting this recess 40b into the side wall potion of mold resin <NUM> in first opening 30a as shown in <FIG>.

As shown in <FIG>, lead bush <NUM> is a lead portion for drawing out electric wire <NUM> connected to circuit board <NUM>. In addition, lead bush <NUM> is a protective member that protects electric wire <NUM> inserted through lead bush <NUM>. Lead bush <NUM> is also called a cable bushing or a bushing. Electric power for energizing coil <NUM> wound around stator <NUM> is supplied to electric wire <NUM>. That is, electric power is supplied to circuit board <NUM> via
electric wire <NUM>. Electric wire <NUM> is a power supply line and is, for example, a lead wire. In the present embodiment, electric wire <NUM> is configured by three lead wires. Each lead wire is configured by a conductor wire serving as a core wire and an insulator for insulating and coating the surface of the conductor wire.

It should be noted that the power for energizing coil <NUM> directly or indirectly is supplied to wire <NUM>, as described above. In addition, a signal for controlling the motor may be supplied to electric wire <NUM> from a control device outside the motor.

As shown in <FIG> and <FIG>, lead bush <NUM> is formed with an insertion through-hole 40a for drawing out electric wire <NUM>. That is, electric wire <NUM> is inserted through insertion through-hole 40a. Insertion through-hole 40a is, for example, a cylindrical through hole. In this case, the shape (opening shape) of insertion through-hole 40a is circular.

The main body of lead bush <NUM> (lead bush main body) is made of a non-metallic material such as a resin material or a ceramic. When the main body of lead bush <NUM> is made of a resin material, lead bush <NUM> is made of, for example, a hard insulating resin material or an insulating resin material having rubber elasticity such as an elastomer. In the present embodiment, the main body of lead bush <NUM> is made of PBT.

As shown in <FIG> and <FIG>, lead bush <NUM> includes metal member <NUM>. Metal member <NUM> is attached to lead bush <NUM>. In the present embodiment, metal member <NUM> is embedded in lead bush <NUM>. Lead bush <NUM> in which metal member <NUM> is embedded can be manufactured by, for example, integral molding such as insert molding.

Metal member <NUM> is formed by a metal plate. Specifically, metal member <NUM> is a tabular flat metal plate. As an example, the metal material forming metal member <NUM> is iron, aluminum, copper or stainless steel.

Second opening 41a is formed in metal member <NUM>. Second opening 41a is a through hole for drawing out electric wire <NUM>. Electric wire <NUM> is inserted into second opening 41a. As an example, the shape of second opening 41a is circular in a side view of mold resin <NUM>.

Second opening 41a is smaller than first opening 30a formed in mold resin <NUM>, and larger than insertion through-hole 40a formed in lead bush <NUM>. That is, when insertion through-hole 40a formed in lead bush <NUM> is viewed from the front (that is, in the side view of mold resin <NUM>), the opening area of second opening 41a formed in metal member <NUM> is smaller than the opening area of first opening 30a formed in mold resin <NUM>, and larger than the opening area of insertion through-hole 40a formed in lead bush <NUM>.

More specifically, when insertion through-hole 40a formed in lead bush <NUM> is viewed from the front, the entire circumference of the opening edge of second opening 41a formed in metal member <NUM> is located inside the entire circumference of the opening edge of first opening 30a formed in mold resin <NUM>, and is located outside the entire circumference of the opening edge of insertion through-hole 40a formed in lead bush <NUM>. As an example, as shown in <FIG>, when the opening width of first opening 30a is W1, the opening width of second opening 41a is W2, and the opening width of insertion through-hole 40a is W3, the relationship of W3 < W2 < W1 is satisfied.

By using lead bush <NUM> including metal member <NUM> having such a configuration, even if coil <NUM> wound around stator <NUM> abnormally generates heat or the like and a layer short circuit occurs to cause ignition inside mold resin <NUM> and the resin portion of lead bush <NUM> melts out, metal member <NUM> which is a non-combustible material will remain without burning. With this, since metal member <NUM> blocks fire from first opening 30a formed in mold resin <NUM> to which lead bush <NUM> is attached to the outside of mold resin <NUM>, it is possible to prevent fire from spouting from molded motor <NUM>. As a result, it is possible to suppress the spread of the fire generated in molded motor <NUM>.

In addition, metal member <NUM> covers first opening 30a formed in mold resin <NUM> in the present embodiment. Specifically, metal member <NUM> is arranged so that the outer shape of metal member <NUM> covers first opening 30a formed in mold resin <NUM> in the direction intersecting with the longitudinal direction (axial direction X) of rotary shaft <NUM>. It should be noted that the direction intersecting with the longitudinal direction of rotary shaft <NUM> means a radial direction centered on shaft center C of rotary shaft <NUM> in a plane orthogonal to the longitudinal direction of rotary shaft <NUM>.

In this way, it is possible to close first opening 30a with metal member <NUM> by covering first opening 30a formed in mold resin <NUM> except for a portion corresponding to the opening area of second opening 41a. With this, even if ignition occurs inside mold resin <NUM> due to a layer short circuit or the like, it is possible to further suppress fire from spouting from first opening 30a.

In addition, mold resin <NUM> is provided with first metal cover <NUM> and second metal cover <NUM> as shown in <FIG>. Each of first metal cover <NUM> and second metal cover <NUM> includes a portion provided in circumferential direction Z of mold resin <NUM> so as to cover coil end 12a positioned at the end portion of coil <NUM> wound around stator <NUM>.

First metal cover <NUM> is an outer cover made of a metal, and is mounted on the first bracket <NUM> side of mold resin <NUM> (the output shaft 21a side). First metal cover <NUM> surrounds coil end 12a and insulator <NUM> positioned on the output shaft 21a side. In addition, first metal cover <NUM> has a hollow cup shape having an opening at the center. A part of first bracket <NUM> positioned on the output shaft 21a side is configured to penetrate the opening included in this first metal cover <NUM>.

Second metal cover <NUM> is an inner cover made of a metal, and is configured to surround the outer periphery of stator <NUM>. Specifically, second metal cover <NUM> surrounds coil end 12a and insulator <NUM>, which are positioned on the side opposite to the output shaft 21a side, and stator core <NUM>. In the present embodiment, second metal cover <NUM> is a cylindrical body that has a cylindrical shape and is open on both sides.

In this way, by covering each of coil end 12a with first metal cover <NUM> and second metal cover <NUM>, even when the ignition occurs inside the molding resin <NUM> due to a layer short circuit or the like, fire is blocked by first metal cover <NUM> and second metal cover <NUM>. With this, it is possible to further suppress fire from spouting from molded motor <NUM>.

It should be noted that either first metal cover <NUM> or second metal cover <NUM> may be provided, but by providing both first metal cover <NUM> and second metal cover <NUM>, it is possible to reliably prevent fire from spouting to the outside of molded motor <NUM>.

As described above, according to molded motor <NUM> of the present embodiment, even if ignition occurs inside mold resin <NUM> due to abnormal heat generation of the coil or the like, it is possible to suppress fire from spouting from the place where lead bush <NUM> is attached in mold resin <NUM> to the outside.

It should be noted that metal member <NUM> is fixed to lead bush <NUM> so as to be positioned outside mold resin <NUM> in the present embodiment, but it is not limited thereto. For example, metal member <NUM> may be fixed to lead bush <NUM> so as to be positioned inside mold resin <NUM>, or may be fixed to lead bush <NUM> so as to be positioned at first opening 30a (middle side) formed in mold resin <NUM>.

In addition, metal member <NUM> is a flat metal plate in the present embodiment, but it is not limited thereto. For example, metal member <NUM> may be a curved metal plate like lead bush <NUM> shown in <FIG>. In this case, the metal plate may be curved along the shape of the side wall portion formed by mold resin <NUM>.

In addition, metal member 41A may include a positioning portion 41b for attaching metal member 41A to mold resin <NUM> like lead bush 40A shown in <FIG>. In the present embodiment, metal member 41A includes a hook portion that can be hooked on a part of mold resin <NUM> as positioning portion 41b. Specifically, as shown in <FIG>, metal member 41A includes, as a positioning portion 41b (hook portion), a bent portion formed by bending both end portions of a rectangular metal plate in a brim shape. This positioning portion 41b (bent portion) is locked to the inner surface of the side wall portion formed by mold resin <NUM> as shown in <FIG>.

In this way, even if the resin portion of lead bush 40A is melted, it is possible to suppress metal member 41A from coming off from first opening 30a formed in mold resin <NUM> by providing positioning portion 41b to metal member 41A. That is, positioning portion 41b included in metal member 41A functions as a fall prevention structure for metal member 41A. With this, it is possible to further suppress fire from spouting from first opening 30a.

Next, molded motor <NUM> according to Embodiment <NUM> will be described with reference to <FIG> and <FIG>. <FIG> is a diagram showing the configuration of lead bush 40B used in molded motor <NUM> according to Embodiment <NUM>, where (a) in <FIG> is a front view, (b) in <FIG> is a side view, and (c) in <FIG> is a top view. It should be noted that also in <FIG>, metal member <NUM> is hatched for convenience. It should be noted that (b) in <FIG> shows a cross-section of metal member <NUM> taken along line B-B of (a) in <FIG>, and (c) in <FIG> shows a cross-section of metal member <NUM> taken along line C-C of (b) in <FIG>. In addition, <FIG> is an enlarged cross-sectional view of a main part of molded motor <NUM> according to Embodiment <NUM>.

In molded motor <NUM> according to Embodiment <NUM> described above, metal member <NUM> of lead bush <NUM> is configured by one metal plate, but in molded motor <NUM> according to the present embodiment as shown in <FIG> and <FIG>, metal member <NUM> included in lead bush 40B is configured by a plurality of metal plates. It should be noted that in the description of Embodiment <NUM> and the subsequent embodiments, the same components as those in Embodiment <NUM> will be designated by the same reference numerals and the description of each component will be incorporated.

Specifically, in lead bush 40B of the present embodiment, metal member <NUM> is configured by a plurality of metal plates covering first opening 30a formed in mold resin <NUM>. The plurality of metal plates configuring metal member <NUM> are arranged so as to overlap each other. More specifically, the plurality of metal plates are arranged such that second opening 41a included in each of the plurality of metal plates overlap each other. It should be noted that metal member <NUM> is configured by two metal plates in the present embodiment.

In addition, also in the present embodiment, each of second openings 41a formed in a plurality of metal plates configuring metal member <NUM> is smaller than first opening 30a formed in mold resin <NUM>, and is larger than insertion through-hole 40a formed in lead bush <NUM>.

With this, also in molded motor <NUM> in the present embodiment, when a layer short circuit is generated and the ignition occurs inside mold resin <NUM>, it is possible to suppress fire from spouting from first opening 30a formed in mold resin <NUM> to the outside of mold resin <NUM>.

In particular, metal member <NUM> is configured by a plurality of metal plates in the present embodiment. That is, first opening 30a formed in mold resin <NUM> is closed by the metal plate having a double structure. With this, it is possible to further suppress fire from spouting from first opening 30a formed in mold resin <NUM> to the outside of mold resin <NUM>.

It should be noted that molded motor <NUM> in the present embodiment has the same configuration as molded motor <NUM> in Embodiment <NUM> described above except that metal member <NUM> is configured by a plurality of metal plates.

In addition, in the present embodiment, both of the two metal plates configuring metal member <NUM> are flat, but the present invention is not limited thereto. For example, one of the two metal plates configuring metal member <NUM> may be curved as in lead bush 40B shown in <FIG>. It should be noted that both of the two metal plates configuring metal member <NUM> may be curved.

In addition, as shown in <FIG>, also in the present embodiment, metal member 41B may have a positioning portion (hook portion) 41b for attaching metal member 41B to mold resin <NUM> similar to metal member 41A shown in <FIG>. That is, metal member 41B may have a fall prevention structure.

Next, molded motor <NUM> according to Embodiment <NUM> will be described with reference to <FIG> is a cross-sectional view showing the peripheral structure of mold resin <NUM> and lead bush 40C in molded motor <NUM> according to Embodiment <NUM>. <FIG> is a perspective view of metal member 41C included in lead bush 40C used in molded motor <NUM>, and <FIG> is a top view of metal member 41C.

As shown in <FIG>, in molded motor <NUM> according to the present embodiment, lead bush 40C is a connector type, and includes protruding portion 41c that protrudes outward from the side wall portion of mold resin <NUM>. Insertion through-hole 40a formed in lead bush 40C in the present embodiment is a small hole for preventing electric wire <NUM> from moving. In the present embodiment, since three electric wires <NUM> are inserted through lead bush 40C, three insertion through-holes 40a are provided. Electric wire <NUM> is inserted into each of insertion through-holes 40a. Electric wire <NUM> inserted into insertion through-hole 40a is held by lead bush 40C.

In addition, metal member 41C of lead bush 40C in the present embodiment is a metal cover that covers the outer surface of protruding portion 41c included in lead bush 40C. The metal cover is made of, for example, iron or the like.

Metal member 41C, which is a metal cover, includes second opening 41a. As shown in <FIG>, the shape of second opening 41a is rectangular in a front view seen in radial direction Y. Also in the present embodiment, second opening 41a is smaller than first opening 30a formed in mold resin <NUM> and larger than each insertion through-hole 40a included in lead bush 40C. Specifically, second opening 41a surrounds three insertion through-holes 40a included in lead bush 40C.

With this, even in molded motor <NUM> in the present embodiment, when a layer short circuit is generated and the ignition occurs inside mold resin <NUM>, it is possible to suppress fire from spouting outside of mold resin <NUM> from first opening 30a formed in mold resin <NUM>.

In addition, metal member 41C includes positioning portion 41b for attaching metal member 41C to mold resin <NUM> in lead bush 40C in the present embodiment. Specifically, metal member 41C includes a hook portion that is hooked on a part of mold resin <NUM> as positioning portion 41b. More specifically, as shown in <FIG>, metal member 41C has a bent portion formed by bending a part of the metal cover into a brim shape as positioning portion 41b (hook portion). As shown in <FIG>, this positioning portion 41b (bent portion) is housed in recess 30b provided in the side wall portion of mold resin <NUM> and is locked to the inner surface of recess 30b.

In this way, by providing positioning portion 41b on metal member 41C, even if the resin portion of lead bush 40C is melted, it is possible to suppress metal member 41C from falling off from first opening 30a formed in mold resin <NUM>. With this, positioning portion 41b included in metal member 41C functions as a fall prevention structure for metal member 41C, and thus it is possible to further suppress fire from spouting from first opening 30a.

It should be noted that molded motor <NUM> according to the present embodiment has the same configuration as the molded motors <NUM> and <NUM> according to Embodiments <NUM> and <NUM> described above except for the above-described features.

Next, molded motor <NUM> according to Embodiment <NUM> will be described with reference to <FIG>. <FIG> is a cross-sectional view of molded motor <NUM> according to Embodiment <NUM>. <FIG> is a diagram showing molded motor <NUM> according to Embodiment <NUM> with lead bush 40D removed. <FIG> and <FIG> are cross-sectional views showing the peripheral structure of mold resin <NUM> and lead bushes 40D and 40E in molded motor <NUM> according to Embodiment <NUM>.

As shown in <FIG> and <FIG>, molded motor <NUM> according to the present embodiment includes stator <NUM>, rotor <NUM> arranged to face stator <NUM>, mold resin <NUM> covering stator <NUM>, and lead bush 40D made of a ceramic.

Stator <NUM> includes stator core <NUM>, coil <NUM>, and insulator <NUM>. Coil <NUM> is a winding coil wound around stator core <NUM> via insulator <NUM>.

Rotor <NUM> includes rotary shaft <NUM>. Rotor <NUM> includes rotor core <NUM> in which a plurality of permanent magnets <NUM> are embedded.

Mold resin <NUM> includes first opening 30a. Lead bush 40D is attached to this first opening 30a.

Lead bush 40D is a drawer portion for drawing out electric wire <NUM>. Lead bush 40D is formed with an insertion through-hole 40a for drawing out electric wire <NUM>. Insertion through-hole 40a is smaller than first opening 30a. That is, when insertion through-hole 40a formed in lead bush 40D is viewed from the front, that is, in radial direction Y intersecting with rotary shaft <NUM>, the opening area of insertion through-hole 40a is smaller than the opening area of first opening 30a formed in mold resin <NUM>.

Specifically, when insertion through-hole 40a formed in lead bush 40D is viewed from the front, the entire circumference of the opening edge of insertion through-hole 40a formed in lead bush 40D is located inside the entire circumference of the opening edge of first opening 30a formed in mold resin <NUM>. As an example, when the opening width of first opening 30a is W11 and the opening width of insertion through-hole 40a is W13 as shown in <FIG>, the relationship of W13 < W11 is satisfied.

In addition, more preferably, it is only needed that lead bush 40E includes inner opening 40c and outer opening 40d for drawing out electric wires <NUM> as shown in <FIG>. Inner opening 40c is located inside molded motor <NUM> in lead bush 40E attached to mold resin <NUM>. Outer opening 40d is located outside molded motor <NUM> in lead bush 40E attached to mold resin <NUM>. In other words, insertion through-hole 40a formed in lead bush 40E includes inner opening 40c that is open to the inside of molded motor <NUM>, that is, the rotary shaft <NUM> side, and outer opening 40d that is open to the outside of molded motor <NUM>, that is, the opposite side to the side where rotary shaft <NUM> is located.

Inner opening 40c is smaller than first opening 30a and larger than outer opening 40d. That is, when insertion through-hole 40a formed in lead bush 40E is viewed from the front, that is, in radial direction Y intersecting with rotary shaft <NUM>, the opening area of inner opening 40c included in insertion through-hole 40a formed inside mold resin <NUM> is smaller than the opening area of first opening 30a formed in mold resin <NUM> and larger than the opening area of outer opening 40d included in insertion through-hole 40a formed outside mold resin <NUM>.

Specifically, when insertion through-hole 40a formed in lead bush 40E is viewed from the front, the entire circumference of the opening edge of inner opening 40c formed inside molded motor <NUM> in lead bush 40E is located inside the entire circumference of the opening edge of first opening 30a formed in mold resin <NUM>, and is located outside the entire circumference of the opening edge of outer opening 40d formed outside molded motor <NUM> in lead bush 40E. As an example, when the opening width of first opening 30a is W21, the opening width of inner opening 40c included in insertion through-hole 40a is W22, and the opening width of outer opening 40d included in insertion through-hole 40a is W23, as shown in <FIG>, the relationship of W23 < W22 < W21 is satisfied.

This configuration facilitates the work of passing electric wire <NUM> from the inside to the outside of lead bush 40E in molded motor <NUM>.

By using ceramic lead bushes 40D and 40E having the configuration described above, even if coil <NUM> wound around stator <NUM> abnormally generates heat or the like and a layer short circuit occurs to cause ignition inside mold resin <NUM>, lead bushes 40D and 40E made of a ceramic, which is a non-combustible material, will remain without burning. With this, since ceramic lead bushes 40D and 40E block fire from first opening 30a formed in mold resin <NUM> to which lead bushes 40D and 40E are attached to the outside of mold resin <NUM>, it is possible to prevent fire from spouting from molded motor <NUM>. As a result, it is possible to suppress the spread of the fire generated in molded motor <NUM>.

The molded motor according to the present disclosure has been described above based on the embodiments, but the present disclosure is not limited to the above embodiments.

For example, although second openings 41a included in metal members <NUM>, 41A and 41B are circular holes in Embodiments <NUM> to <NUM> described above, the invention is not limited thereto, and the metal members may be in a cutout shape in which a part of the metal members is cut out. That is, second opening 41a is not limited to a closed hole, and may be a partially opened hole.

In addition, metal members <NUM> and 41A are embedded inside the main body of lead bush <NUM> in Embodiments <NUM> and <NUM> described above, but the present invention is not limited thereto. Specifically, the metal member may be fixed to lead bush <NUM> by forming a gap in a part of lead bush <NUM> and inserting the metal member (metal plate) into this gap.

In addition, the number of magnetic poles of rotor <NUM> is <NUM> (that is, the number of permanent magnets <NUM> is <NUM>) in each of Embodiments <NUM> to <NUM> described above, but the number is not limited thereto. Any number of magnetic poles of rotor <NUM> can be applied.

Forms obtained by applying various variations that are conceived by those skilled in the art to the embodiments described above, and forms achieved by arbitrarily combining the components and functions of the embodiments described above.

Claim 1:
A molded motor (<NUM>, <NUM>, <NUM>), comprising:
a stator (<NUM>) that includes a stator core (<NUM>) and a coil (<NUM>) wound around the stator core (<NUM>) via an insulator (<NUM>);
a rotor (<NUM>) that is arranged to face the stator (<NUM>) and includes a rotor core (<NUM>) and a rotary shaft (<NUM>);
a mold resin (<NUM>) that includes a first opening (30a) and covers the stator (<NUM>); and
a lead bush (<NUM>, 40A, 40B, 40C, 40D, 40E) that is attached to the first opening (30a) and includes an insertion through-hole (40a) for drawing out an electric wire (<NUM>), characterized in that
the lead bush (<NUM>, 40A, 40B, 40C, 40D, 40E) includes a metal member (<NUM>, 41A, 41B, 41C) including a second opening (41a) for drawing out the electric wire (<NUM>), the second opening (41a) being smaller than the first opening (30a) and larger than the insertion through-hole (40a), wherein the insertion through-hole (40a) extends through the second opening (41a); wherein
an outer shape of the metal member (<NUM>, 41A, 41B, 41C) covers the first opening (30a).