Patent Description:
Conventionally, a blower is used for cooling a heat generating device or the like. For example, PTL <NUM> discloses a sirocco fan used for cooling an in-vehicle battery. The sirocco fan described in PTL <NUM> is intended to reduce vibration and noise by improving assembly accuracy of the fan.

However, in the conventional blower as described in PTL <NUM>, it has been found that minute foreign matters such as sand and dust are sucked into a bearing of a motor at the time of use, and the bearing may be damaged by the sucked minute foreign matters. When the bearing is damaged in this way, noise is generated or the life of the motor is shortened. In particular, such a problem becomes more remarkable when the blower is used in an environment with a lot of dust and the like. PTL <NUM> describes a blower, comprising a fan and a motor, wherein the motor includes a shaft including an axis, a bearing that supports the shaft, and a motor case that covers at least a part of the bearing, the fan include a main plate having a first surface facing the motor case and a second surface opposite to the first surface and connected to the shaft, and a plurality of blades erected on the second surface of the main plate, and arranged radially with respect to the axis included in the shaft, at least one of the fan and the motor case includes one or more ribs, and the one or more ribs are located apart from the shaft in a radial direction orthogonal to the axis between the first surface of the main plate and the motor case, and surround the shaft, wherein in the main plate, one or more through holes penetrating between the first surface and the second surface are formed between the axis included in the shaft and a region where the plurality of blades are erected.

The present disclosure has been made to solve such a problem, and an object of the present disclosure is to provide a blower capable of reducing entry of minute foreign matters into a bearing of a motor.

In order to achieve the above object, the invention is defined by the independent claims. Further embodiments are specified in the dependent claims.

According to the present disclosure, it is possible to provide the blower capable of reducing entry of minute foreign matters into the bearing included in the motor.

Hereinafter, exemplary embodiments of the present disclosure will be described with reference to the drawings. Note that each of the exemplary embodiments described below illustrates a specific example of the present disclosure. Therefore, numerical values, shapes, materials, components, arrangement positions and connection modes of the components, and the like shown in the following exemplary embodiments are merely examples, and are not intended to limit the present disclosure.

Each drawing is a schematic diagram, and is not necessarily strictly illustrated. In each drawing, substantially the same components are denoted by the same reference numerals, and redundant description will be omitted or simplified.

An overall configuration of blower <NUM> according to a first exemplary embodiment will be described with reference to <FIG>. <FIG> are a perspective view and a top view illustrating an appearance of blower <NUM> according to the first exemplary embodiment, respectively. <FIG> is a cross-sectional view illustrating an internal structure of blower <NUM> according to the first exemplary embodiment. <FIG> illustrates a cross section taken along line III-III illustrated in <FIG>, in other words, a cross section taken along a plane passing through axis C of shaft <NUM> included in blower <NUM>.

Blower <NUM> illustrated in <FIG> is a sirocco fan that blows out a gas sucked from suction port <NUM> from blow-out port <NUM>. As illustrated in <FIG>, blower <NUM> includes case <NUM>, fan <NUM>, and motor <NUM>. Blower <NUM> sucks a gas from suction port <NUM> and blows the gas out from blow-out port <NUM> by rotating fan <NUM> by motor <NUM>.

As illustrated in <FIG>, case <NUM> is an appliance that serves as an outer shell of blower <NUM>. Suction port <NUM> and blow-out port <NUM> are formed in case <NUM>. As illustrated in <FIG>, fan <NUM> and motor <NUM> are disposed inside case <NUM>. In <FIG>, motor <NUM> is fixed to a bottom of case <NUM>. Fan <NUM> is fixed to shaft <NUM> of motor <NUM>. Suction port <NUM> formed in case <NUM> is disposed on axis C (that is, a rotation axis of motor <NUM>) included in shaft <NUM>. Blow-out port <NUM> is disposed at a position radially away from axis C. Here, a radial direction refers to a direction orthogonal to axis C. As a result, a gas sucked from suction port <NUM> in a direction along axis C is blown out from blow-out port <NUM> in a direction intersecting axis C.

A material forming case <NUM> is not particularly limited, and may be, for example, polybutylene terephthalate (PBT), polycarbonate (PC), polypropylene (PP), or a mixed material thereof.

Motor <NUM> is a device that rotates fan <NUM>. As illustrated in <FIG>, motor <NUM> includes shaft <NUM>, bearing <NUM>, and motor case <NUM>. Motor <NUM> further includes rotor <NUM> and stator <NUM>. Motor <NUM> is not particularly limited as long as it is a motor including shaft <NUM>, bearing <NUM>, and motor case <NUM>, but is an inner rotor brushless motor in the present exemplary embodiment.

Shaft <NUM> is a columnar member that rotates with respect to motor case <NUM>. A material forming shaft <NUM> is not particularly limited, but may be, for example, metal such as stainless steel.

Bearing <NUM> is a member that supports shaft <NUM>. Bearing <NUM> has a substantially cylindrical shape. An inner surface of bearing <NUM> is attached to an outer surface of shaft <NUM> along a direction of axis C in which shaft <NUM> extends. An outer surface of bearing <NUM> is fixed to motor case <NUM>. Bearing <NUM> can reduce the rotational resistance of shaft <NUM> to motor case <NUM>. As bearing <NUM>, for example, a sintered oil-impregnated bearing can be used.

Motor case <NUM> is a housing that covers at least a part of bearing <NUM>. Motor case <NUM> covers a part of shaft <NUM>, bearing <NUM>, rotor <NUM>, stator <NUM>, and the like. Motor case <NUM> is fixed to case <NUM>. A material forming motor case <NUM> is not particularly limited, but may be, for example, a galvanized steel sheet or the like. In the present exemplary embodiment, motor case <NUM> includes top surface 54a, side surface 54b, step upper surface 54c, step side surface 54d, and bottom surface 54e.

Top surface 54a is a surface facing first surface 32a of main plate <NUM> included in fan <NUM>. Top surface 54a is a surface intersecting with axis C included in shaft <NUM>. Top surface 54a has a substantially circular shape. Side surface 54b is a surface extending from an outer edge of top surface 54a along a direction in which shaft <NUM> of motor <NUM> extends. Side surface 54b has an annular shape surrounding shaft <NUM> of motor <NUM>. Side surface 54b has a substantially cylindrical shape. Step upper surface 54c extends outward from an end part of side surface 54b on a side farther from fan <NUM>. Step upper surface 54c is a surface facing first surface 32a of main plate <NUM> of fan <NUM>. Step upper surface 54c is a flat surface having a substantially annular shape. Step side surface 54d is a surface extending in parallel from an outer edge of step upper surface 54c along shaft <NUM> that is a rotation axis of motor <NUM>. Step side surface 54d has an annular shape surrounding shaft <NUM> that is the rotation axis of motor <NUM>. Step side surface 54d has a substantially cylindrical shape. Bottom surface 54e is a surface that covers a region surrounded by an end part of step side surface 54d on a side farther from step upper surface 54c.

Rotor <NUM> is a member that rotates with respect to stator <NUM>. Rotor <NUM> is attached to an outer surface of shaft <NUM> along the direction of axis C of shaft <NUM>.

Stator <NUM> is a member that rotates rotor <NUM>. Stator <NUM> is disposed around rotor <NUM> and fixed to motor case <NUM>.

As illustrated in <FIG>, fan <NUM> is a component that is connected to shaft <NUM> included in motor <NUM>, and rotates about axis C included in shaft <NUM>. When fan <NUM> rotates in a predetermined direction, a gas flows from suction port <NUM> of blower <NUM> to blow-out port <NUM>. A material forming fan <NUM> is not particularly limited. However, for example, a resin such as PBT, PC, or PP, or a mixed material thereof may be used. Fan <NUM> is made of polypropylene containing about <NUM> wt% of glass fiber.

Hereinafter, the configuration of fan <NUM> will be described with reference to <FIG> and <FIG> together with <FIG>. <FIG> is a first perspective view illustrating an appearance of fan <NUM> according to the first exemplary embodiment. <FIG> is a second perspective view illustrating the appearance of fan <NUM> according to the first exemplary embodiment. As illustrated in <FIG>, fan <NUM> includes main plate <NUM>, a plurality of blades <NUM>, boss <NUM>, blocking member <NUM>, and blocking member <NUM>. Fan <NUM> further includes annular member <NUM> and reinforcing member <NUM>.

As illustrated in <FIG>, main plate <NUM> has first surface 32a facing motor case <NUM> and second surface 32b opposite to first surface 32a. Main plate <NUM> is a member connected to shaft <NUM>. Main plate <NUM> is connected to shaft <NUM> on its central axis. Here, the central axis of main plate <NUM> is a rotation axis of fan <NUM>, and passes through a center of main plate <NUM>. Main plate <NUM> has a conical shape. First surface 32a and second surface 32b are surfaces located inside and outside conical main plate <NUM>, respectively. At least a part of motor case <NUM> is disposed inside a conical space formed by main plate <NUM>.

In main plate <NUM>, one or more through holes <NUM> penetrating between first surface 32a and second surface 32b are formed between axis C of shaft <NUM> to which main plate <NUM> is connected and a region where the plurality of blades <NUM> are erected. More specifically, one or more through holes <NUM> are disposed between a region where boss <NUM> of main plate <NUM> is disposed and a region where the plurality of blades <NUM> are erected. By forming such through holes <NUM>, an assembly worker who assembles blower <NUM> can insert a fingertip or the like into through holes <NUM> formed in fan <NUM>. Therefore, handling of fan <NUM> can be facilitated. In addition, the material required to form fan <NUM> can be reduced, and the weight of fan <NUM> can be reduced. Therefore, power required to rotate fan <NUM> can be reduced. In the present exemplary embodiment, a plurality of through holes <NUM> are formed in main plate <NUM>. Thus, the assembly worker of blower <NUM> can grip fan <NUM> using the plurality of through holes <NUM>. Therefore, handling of fan <NUM> can be further facilitated. The number of through holes <NUM> is not particularly limited, but in the example illustrated in <FIG>, the number of through holes <NUM> is six.

Blades <NUM> are erected on second surface 32b of main plate <NUM>. Blades <NUM> are plate-shaped members arranged radially with respect to axis C (that is, a central axis of main plate <NUM>) included in shaft <NUM>. Blade <NUM> may be curved as illustrated in <FIG> and <FIG>. The plurality of blades <NUM> are disposed along an outer peripheral edge of main plate <NUM>.

Annular member <NUM> is an annular member attached to an end part opposite to main plate <NUM> with respect to the plurality of blades <NUM>.

Boss <NUM> is attached to an outer surface of shaft <NUM> included in motor <NUM>. Boss <NUM> is a member fixed to shaft <NUM>. Boss <NUM> is erected on first surface 32a of main plate <NUM>. Boss <NUM> has a cylindrical shape surrounding axis C included in shaft <NUM>. An interval between boss <NUM> and motor case <NUM> of motor <NUM> is larger than <NUM>. Accordingly, interference between boss <NUM> and motor case <NUM> can be suppressed. Note that the interval between boss <NUM> and motor case <NUM> means a length of a gap between boss <NUM> and motor case <NUM>.

Each of blocking member <NUM> and blocking member <NUM> is a member that prevents minute foreign matters such as sand from entering bearing <NUM> through the space between main plate <NUM> of fan <NUM> and motor case <NUM>. Each of blocking member <NUM> and blocking member <NUM> is disposed apart from shaft <NUM> in the radial direction between first surface 32a of main plate <NUM> and motor case <NUM>, and surrounds shaft <NUM>. Here, a state in which each blocking member surrounds shaft <NUM> includes not only a state in which each blocking member surrounds the entire periphery of shaft <NUM> without interruption, but also a state in which each blocking member is disposed around shaft <NUM> and a part of each blocking member is interrupted. For example, each blocking member may have a substantially annular shape surrounding shaft <NUM>, and each blocking member may be separated into a plurality of portions in a circumferential direction with axis C included in shaft <NUM> as a central axis. Each blocking member may be disposed in a range of an angle exceeding <NUM>% of a total circumferential angle (<NUM>°) among circumferential angles having axis C included in shaft <NUM> as a central axis.

Each of blocking member <NUM> and blocking member <NUM> has an annular shape surrounding shaft <NUM>. More specifically, as illustrated in <FIG>, each of blocking member <NUM> and blocking member <NUM> has a cylindrical shape with the rotation axis (that is, axis C included in shaft <NUM>) of motor <NUM> as a central axis. As illustrated in <FIG>, blocking member <NUM> and blocking member <NUM> have different distances from axis C included in shaft <NUM>. Each of blocking member <NUM> and blocking member <NUM> is disposed away from an outer edge of main plate <NUM> toward a side of the rotation axis.

Reinforcing member <NUM> is a member that connects first surface 32a of main plate <NUM> and boss <NUM>. Reinforcing member <NUM> is a plate-like member extending in the radial direction from axis C included in shaft <NUM>. Consequently, boss <NUM> can be prevented from being detached from main plate <NUM>.

Next, an operation of blower <NUM> according to the present exemplary embodiment will be described with reference to <FIG> in comparison with a comparative example. <FIG> is a partial cross-sectional view illustrating an internal structure of blower <NUM> according to a comparative example. <FIG> illustrates a part of the vicinity of motor <NUM> and main plate <NUM> in a cross section taken along a plane passing through axis C of shaft <NUM> included in blower <NUM>.

As illustrated in <FIG>, blower <NUM> according to the comparative example includes case <NUM>, fan <NUM>, and motor <NUM>. Case <NUM> and motor <NUM> of blower <NUM> according to the comparative example have the same configurations as case <NUM> and motor <NUM> of blower <NUM> according to the present exemplary embodiment, respectively.

Fan <NUM> included in blower <NUM> according to the comparative example includes main plate <NUM>, a plurality of blades <NUM>, and boss <NUM> similarly to fan <NUM> according to the present exemplary embodiment. Main plate <NUM> and the plurality of blades <NUM> included in fan <NUM> have the same configurations as main plate <NUM> and the plurality of blades <NUM> according to the present exemplary embodiment, respectively. Boss <NUM> differs from boss <NUM> according to the present exemplary embodiment in the length in a direction of the rotation axis, that is, in a direction of axis C, and coincides with boss <NUM> in other configurations. Boss <NUM> has a shorter length in the direction of the rotation axis than boss <NUM> according to the present exemplary embodiment. Therefore, interval Gb between boss <NUM> and motor case <NUM> in blower <NUM> according to the comparative example is larger than interval Gb between boss <NUM> and motor case <NUM> in blower <NUM> according to the present exemplary embodiment. Specifically, interval Gb is <NUM> in blower <NUM> according to the present exemplary embodiment, but interval Gb is <NUM> in blower <NUM> according to the comparative example.

Fan <NUM> according to the comparative example is also different from fan <NUM> according to the present exemplary embodiment in not including blocking member <NUM> and blocking member <NUM>.

In blower <NUM> according to the comparative example, minute foreign matters such as sand and dust contained in a gas sucked through suction port <NUM> can enter between main plate <NUM> and motor <NUM> through a gap between fan <NUM> and case <NUM> as indicated by a broken arrow in <FIG>. The minute foreign matters can also enter between main plate <NUM> and motor <NUM> through through holes <NUM> formed in main plate <NUM> of fan <NUM>. The minute foreign matters that have entered between main plate <NUM> and motor <NUM> may enter a gap between shaft <NUM> of motor <NUM> and bearing <NUM> of motor <NUM>.

In blower <NUM> according to the comparative example, as described above, the minute foreign matters can enter between main plate <NUM> of fan <NUM> and top surface 54a of motor case <NUM> of motor <NUM>. In particular, when main plate <NUM> has a conical surface shape, a relatively large space is formed between main plate <NUM> and top surface 54a of motor case <NUM>. Therefore, the minute foreign matters easily enter between main plate <NUM> and top surface 54a of motor case <NUM>.

On the other hand, in blower <NUM> according to the present exemplary embodiment, fan <NUM> includes blocking member <NUM> and blocking member <NUM> that are disposed apart from shaft <NUM> in the radial direction between first surface 32a of main plate <NUM> and motor case <NUM>, and surround shaft <NUM>. A portion having a narrow gap between main plate <NUM> and motor case <NUM> can be formed by blocking member <NUM> and blocking member <NUM>. Therefore, even when the minute foreign matters enter between main plate <NUM> and motor <NUM>, at least a part of the minute foreign matters heading toward shaft <NUM> and bearing <NUM> can be blocked by each blocking member. Therefore, blower <NUM> according to the present exemplary embodiment can reduce the intrusion of the minute foreign matters into bearing <NUM> of motor <NUM>.

In the present exemplary embodiment, each of blocking member <NUM> and blocking member <NUM> is disposed to be separated from an outer edge of main plate <NUM> on a side of the rotation axis, that is, on a side of shaft <NUM>. Accordingly, the minute foreign matters can flow into the space sandwiched between each blocking member and a portion outside the blocking member disposed on main plate <NUM>. Therefore, the minute foreign matters can be reduced from flowing into a side of the rotation axis from each blocking member.

Each blocking member has an annular shape surrounding shaft <NUM>. As a result, entry of the minute foreign matters into bearing <NUM> from all directions can be reduced with axis C included in shaft <NUM> as a central axis.

Each blocking member has a cylindrical shape with the rotation axis of motor <NUM> (axis C of shaft <NUM>) as a central axis. As a result, since the shape of fan <NUM> can be axisymmetric with respect to the rotation axis of motor <NUM>, vibration and noise during rotation of fan <NUM> can be reduced.

Fan <NUM> includes two blocking members having different distances from axis C included in shaft <NUM>. As a result, even when the minute foreign matters pass through the gap between blocking member <NUM> having a larger distance from the rotation axis of motor <NUM> and motor case <NUM>, blocking member <NUM> having a smaller distance from the rotation axis can block the minute foreign matters. In other words, even when the minute foreign matters pass through the gap between blocking member <NUM> having the larger radial distance from shaft <NUM> of motor <NUM> and motor case <NUM>, blocking member <NUM> having the smaller radial distance from shaft <NUM> can block the minute foreign matters.

Each blocking member is disposed at a position closer to shaft <NUM> than through hole <NUM> is. As a result, it is possible to reduce the minute foreign matters that have entered between main plate <NUM> and motor <NUM> from through hole <NUM> from entering bearing <NUM>.

In the present exemplary embodiment, interval Gb between boss <NUM> and motor case <NUM> is <NUM>, and is narrower than interval Gb between boss <NUM> and motor case <NUM> in the comparative example. This can reduce the minute foreign matters entering between boss <NUM> and motor case <NUM>. Therefore, it is possible to reduce the minute foreign matters entering bearing <NUM>. Noted that interval Gb is not limited to <NUM>. Interval Gb may be greater than <NUM> and about <NUM> or less. As a result, the minute foreign matters entering bearing <NUM> can be reduced as compared with the case where interval Gb is <NUM> as in blower <NUM> according to the comparative example.

Next, in order to confirm the effect of blower <NUM> according to the present exemplary embodiment, a result of analysis using a computer will be described with reference to <FIG> is a diagram illustrating analysis results of the blowers according to the comparative example and the first exemplary embodiment. <FIG> also illustrates an analysis result of blowers according to first to third modified examples.

First, analysis conditions of the blowers according to the comparative example and the first exemplary embodiment will be described. In this analysis, fluid analysis of a gas sucked and blown out by each blower was performed. Here, the gas contains particles simulating minute foreign matters, and in the analysis, position of each particle moving with the gas was tracked. In this analysis, a volume of the gas sucked by each blower was <NUM><NUM>/h, and a rotation speed of each fan was <NUM> rpm. A density of the particles was <NUM>/mm<NUM>. Diameters of the particles were distributed in a range of <NUM> or more and <NUM> or less. The number of the particles flowing into each blower was <NUM>,<NUM>/sec. Under the above conditions, the number of the particles reaching a cylinder between the boss of each fan and motor case <NUM> for <NUM> sec was defined as an intrusion amount of the particles. More specifically, the number of the particles reaching a cylindrical space disposed between the boss and motor case <NUM> was defined as an intrusion amount of the particles. Here, a central axis of the cylindrical space is the rotation axis (that is, shaft <NUM>) of motor <NUM>, has a diameter of <NUM>, and has a height equal to interval Gb.

As illustrated in <FIG>, the intrusion amount was <NUM> in blower <NUM> according to the comparative example, whereas the intrusion amount was reduced to <NUM> in blower <NUM> according to the present exemplary embodiment, which corresponds to about <NUM>% of the intrusion amount in blower <NUM> according to the comparative example. As described above, according to blower <NUM> of the present exemplary embodiment, it was confirmed that the intrusion amount of the minute foreign matters could be significantly reduced as compared with blower <NUM> according to the comparative example.

In fan <NUM> according to the present exemplary embodiment, as compared with fan <NUM> according to the comparative example, the length of boss <NUM> in the direction of axis C is extended, and blocking member <NUM> and blocking member <NUM> are added, the mass thereof is increased more than that of fan <NUM> according to the comparative example. <FIG> also illustrates an amount of increase in the mass of fan <NUM> with respect to the weight of fan <NUM> according to the comparative example. As illustrated in <FIG>, the increase amount of the mass of fan <NUM> according to the present exemplary embodiment with respect to the mass of fan <NUM> of the comparative example is <NUM>. This increase amount corresponds to about <NUM>% of the total mass <NUM> of fan <NUM>. As described above, according to fan <NUM> of the present exemplary embodiment, it is possible to reduce the intrusion of the minute foreign matters into bearing <NUM> while suppressing the increase in mass.

Next, effects of the components according to the present exemplary embodiment will be described using analysis results of the blowers according to the first to third modified examples illustrated in <FIG>. As illustrated in a shape field of the first modified example in <FIG>, the blower according to the first modified example is a blower in which only boss <NUM> of blower <NUM> according to the comparative example is replaced with boss <NUM> of blower <NUM> according to the present exemplary embodiment. As illustrated in a shape field of the second modified example in <FIG>, the blower according to the second modified example is a blower in which only blocking member <NUM> of blower <NUM> according to the present exemplary embodiment is added to blower <NUM> according to the comparative example. As illustrated in a shape field of the third modified example in <FIG>, the blower according to the third modified example is a blower in which only blocking member <NUM> of blower <NUM> according to the present exemplary embodiment is added to blower <NUM> according to the comparative example.

In the blower according to the first modified example, the intrusion amount was able to be reduced to <NUM>, which corresponds to about <NUM>% of the intrusion amount in blower <NUM> according to the comparative example. As described above, the effect of reducing the intrusion of the minute foreign matters by extending the length of boss <NUM> according to the present exemplary embodiment from boss <NUM> according to the comparative example was confirmed. The increase amount of the mass of the fan according to the first modified example with respect to the mass of fan <NUM> of the comparative example was <NUM>. This increase amount corresponds to about <NUM>% of the total mass <NUM> of fan <NUM>. As described above, according to the fan according to the first modified example, it is possible to reduce the intrusion of the minute foreign matters into bearing <NUM> while suppressing the increase in mass.

In the blowers according to the second modified example and the third modified example, the intrusion amount was able to be reduced to <NUM>, which corresponds to about <NUM>% of the intrusion amount in blower <NUM> according to the comparative example. In addition, the amount of increase in the mass of the fan according to the second modified example is <NUM> with respect to the mass of fan <NUM> of the comparative example. This increase amount corresponds to about <NUM>% of the total mass <NUM> of fan <NUM>. The amount of increase in the mass of the fan according to the third modified example is <NUM> with respect to the mass of fan <NUM> of the comparative example. This increase amount corresponds to about <NUM>% of the total mass <NUM> of fan <NUM>. As described above, according to the fans of the second modified example and the third modified example, it is possible to reduce the intrusion of the minute foreign matters into bearing <NUM> while suppressing the increase in mass.

From the analysis results of the blowers according to the first modified example to the third modified example, it has been confirmed that each of boss <NUM>, blocking member <NUM>, and blocking member <NUM> according to the present exemplary embodiment has an effect of reducing the intrusion of the minute foreign matters into bearing <NUM>. Furthermore, in the present exemplary embodiment, it has been confirmed that by combining the configurations of the first modified example to the third modified example, the effect of reducing the intrusion of the minute foreign matters into bearing <NUM> can be further enhanced as compared with each of the first modified example to the third modified example.

As described above, blower <NUM> of the present exemplary embodiment is blower <NUM> including fan <NUM> and motor <NUM>, and motor <NUM> includes shaft <NUM> including axis C, bearing <NUM> that supports shaft <NUM>, and motor case <NUM> that covers at least a part of bearing <NUM>. Fan <NUM> includes main plate <NUM> having first surface 32a facing motor case <NUM> and second surface 32b opposite to first surface 32a, and connected to shaft <NUM>, and a plurality of blades <NUM> erected on second surface 32b of main plate <NUM> and arranged radially with respect to axis C included in shaft <NUM>. At least one of fan <NUM> and motor case <NUM> includes one or more blocking members <NUM>, <NUM>. One or more blocking members <NUM>, <NUM> are located apart from shaft <NUM> in the radial direction orthogonal to the axis between first surface 32a of main plate <NUM> and motor case <NUM>, and surround shaft <NUM>.

As a result, it is possible to provide blower <NUM> capable of reducing the intrusion of the minute foreign matters into bearing <NUM> of motor <NUM>.

Furthermore, fan <NUM> may include boss <NUM> attached to the outer surface of shaft <NUM> and supporting shaft <NUM>.

Further, motor case <NUM> may include side surface 54b that extends along a direction in which shaft <NUM> of motor <NUM> extends and surrounds shaft <NUM>.

A blower according to a second exemplary embodiment will be described. The blower according to the present exemplary embodiment is different from blower <NUM> according to the first exemplary embodiment mainly in the configuration of a blocking member included in the fan. The following blower according to the present exemplary embodiment will be described focusing on differences from blower <NUM> according to the first exemplary embodiment.

First, an overall configuration of a blower not forming part of the invention will be described with reference to <FIG> is a partial cross-sectional view illustrating an internal structure of blower <NUM> according to the second exemplary embodiment. <FIG> illustrates a part of the vicinity of motor <NUM> and main plate <NUM> in a cross section taken along a plane passing through axis C included in shaft <NUM> of blower <NUM>.

As illustrated in <FIG>, blower <NUM> according to the present exemplary embodiment includes case <NUM>, fan <NUM>, and motor <NUM>. Case <NUM> and motor <NUM> of blower <NUM> according to the present exemplary embodiment have the same configurations as case <NUM> and motor <NUM> of blower <NUM> according to the first exemplary embodiment, respectively.

Fan <NUM> of blower <NUM> according to the present exemplary embodiment includes main plate <NUM>, a plurality of blades <NUM>, and boss <NUM>, similarly to fan <NUM> according to the first exemplary embodiment. Main plate <NUM> and the plurality of blades <NUM> included in fan <NUM> have configurations similar to those of main plate <NUM> and the plurality of blades <NUM> according to the first exemplary embodiment, respectively. Boss <NUM> has the same configuration as boss <NUM> of fan <NUM> according to the comparative example described above. That is, boss <NUM> has a shorter length in the rotation axis direction of motor <NUM>, that is, in the direction of axis C of shaft <NUM> than boss <NUM> according to the first exemplary embodiment.

Fan <NUM> according to the present exemplary embodiment further includes blocking member <NUM>. As with each blocking member according to the first exemplary embodiment, blocking member <NUM> is disposed radially apart from shaft <NUM> between first surface 32a of main plate <NUM> and motor case <NUM>, and surrounds shaft <NUM>. Blocking member <NUM> according to the present exemplary embodiment is disposed at a position facing side surface 54b of motor case <NUM>. In addition, blocking member <NUM> has an annular shape surrounding shaft <NUM>. More specifically, blocking member <NUM> has a cylindrical shape with the rotation axis of the motor <NUM> as a central axis.

As illustrated in <FIG>, blocking member <NUM> is disposed at a position farther from shaft <NUM> than through hole <NUM> is in the radial direction. Blocking member <NUM> is disposed at a position closer to shaft <NUM> than step side surface 54d of motor case <NUM> is in the radial direction.

Next, an operation of blower <NUM> according to the present exemplary embodiment will be described with reference to <FIG>. Since blower <NUM> according to the present exemplary embodiment includes blocking member <NUM>, the same effects as those of the blocking members according to the first exemplary embodiment can be obtained. By disposing blocking member <NUM> at a position facing side surface 54b included in motor case <NUM>, a maze structure (labyrinth) is formed between main plate <NUM> of fan <NUM> and motor case <NUM>. By forming such a maze structure, it is possible to reduce the minute foreign matters from entering the vicinity of the rotation axis, that is, the vicinity of bearing <NUM>.

Blocking member <NUM> is disposed at a position closer to shaft <NUM> than step side surface 54d is in the radial direction. As a result, since blocking member <NUM> is disposed above step upper surface 54c connected to step side surface 54d, a further maze structure is formed between step upper surface 54c and blocking member <NUM>. By forming such a maze structure, it is possible to further reduce the minute foreign matters from entering the vicinity of the rotation axis, that is, the vicinity of bearing <NUM>.

Since an airflow as indicated by a broken line arrow in <FIG> can be formed in a space sandwiched between blocking member <NUM> and a portion outside blocking member <NUM> arranged on main plate <NUM>, the minute foreign matters can flow into the space. Therefore, it is possible to reduce the minute foreign matters from entering a side of the rotation axis, that is, a side of bearing <NUM> from blocking member <NUM>.

Blocking member <NUM> has an annular shape surrounding shaft <NUM>. As a result, it is possible to reduce the minute foreign matters from entering bearing <NUM> from all directions with axis C included in shaft <NUM> as a central axis.

Blocking member <NUM> has a cylindrical shape with the rotation axis of motor <NUM> as a central axis. In other words, blocking member <NUM> has a cylindrical shape with axis C included in shaft <NUM> as a central axis. As a result, since the shape of fan <NUM> can be axisymmetric with respect to the rotation axis of motor <NUM>, vibration and noise during rotation of fan <NUM> can be reduced.

Next, in order to confirm the effect of blower <NUM> according to the present exemplary embodiment, a result of analysis using a computer will be described with reference to <FIG> is a diagram illustrating analysis results of the blowers according to the comparative example and the second exemplary embodiment.

<FIG> illustrates a result of analysis under the same conditions as the analysis conditions of blower <NUM> according to the above-described first exemplary embodiment.

As shown in <FIG>, in blower <NUM> according to the comparative example, the intrusion amount was <NUM>. On the other hand, in blower <NUM> according to the present exemplary embodiment, the intrusion amount was able to be reduced to <NUM>, which corresponds to about <NUM>% of the intrusion amount in blower <NUM> according to the comparative example. As described above, according to blower <NUM> of the present exemplary embodiment, it was confirmed that the intrusion amount of the minute foreign matters could be significantly reduced as compared with blower <NUM> according to the comparative example.

Although the electric blower according to the present disclosure has been described above based on the exemplary embodiments, the present disclosure is not limited to the exemplary embodiments.

For example, in each of the above exemplary embodiments, the fan includes the blocking member. However, motor case <NUM> of motor <NUM> may include a blocking member, or both the fan and motor case <NUM> may include a blocking member. That is, at least one of the fan and motor case <NUM> may include one or more blocking members.

In the above-described first exemplary embodiment, fan <NUM> includes two blocking members <NUM> and <NUM>. However, the number of the blocking members is not limited to two, and may be one or more. For example, as in the second modified example and the third modified example illustrated in <FIG>, the number of the blocking members may be one.

Fan <NUM> includes two blocking members having different radial distances from axis C included in shaft <NUM>. However, three or more blocking members having different distances from axis C included in shaft <NUM> may be provided. That is, fan <NUM> may include a plurality of blocking members having different distances from axis C included in shaft <NUM>.

In each of the above exemplary embodiments, the entire bearing is covered with the motor case. However, a part of the bearing may be covered. For example, a part of the bearing on a side of the fan may be exposed to an outside from the motor case.

Claim 1:
A blower (<NUM>, <NUM>) comprising a fan (<NUM>,<NUM>) and a motor (<NUM>), wherein
the motor (<NUM>) includes:
a shaft (<NUM>) including an axis;
a bearing (<NUM>) that supports the shaft (<NUM>); and
a motor case (<NUM>) that covers at least a part of the bearing (<NUM>),
the fan (<NUM>,<NUM>) includes:
a main plate (<NUM>) having a first surface (32a) facing the motor case (<NUM>) and a second surface (32b) opposite to the first surface (32a), and connected to the shaft (<NUM>); and
a plurality of blades (<NUM>) erected on the second surface (32b) of the main plate (<NUM>), and arranged radially with respect to the axis included in the shaft (<NUM>),
at least one of the fan (<NUM>,<NUM>) and the motor case (<NUM>) includes one or more blocking members (<NUM>, <NUM>), and
the one or more blocking members (<NUM>, <NUM>) are located apart from the shaft (<NUM>) in a radial direction orthogonal to the axis between the first surface (32a) of the main plate (<NUM>) and the motor case (<NUM>), and surround the shaft (<NUM>),
wherein in the main plate (<NUM>), one or more through holes (<NUM>) penetrating between the first surface (32a) and the second surface (32b) are formed between the axis included in the shaft (<NUM>) and a region where the plurality of blades (<NUM>) are erected,
characterized in that the one or more blocking members (<NUM>, <NUM>) are disposed at positions closer to the shaft (<NUM>) than the one or more through holes (<NUM>) are, so as to be configured to prevent minute foreign matters from entering the bearing (<NUM>) through the space between the main plate (<NUM>) and the motor case (<NUM>).