BLOWER WITH INDENTATIONS

According to examples, a blower may include a housing, a fan positioned within the housing, the fan having a fan edge, and a fan housing section encircling the fan, the fan housing section having an inner surface that spans an inner circumference of the housing section, the inner surface having a plurality of indentations and being spaced within a certain distance from the fan edge.

FIELD

The present disclosure relates to a blower having a housing and a fan, in which an interior section of the housing around the fan includes a plurality of indentations. The indentations are to increase turbulence around an outer edge of the fan as the fan rotates, which decreases an effective gap between the outer edge of the fan and the interior section of the housing. The decrease in the effective gap size may reduce the back flow of air through the gap, which may improve airflow and/or may increase velocity of the airflow forced through the blower.

BACKGROUND

Blowers are in common use to remove debris such as leaves and grass clippings through the generation of a fast moving stream of airflow from the blowers. The blowers include impellers to draw air into the blowers through inlets and to force airflow out of the blowers through outlets. The blowers typically include a housing and a blower tube fitted over the outlet of the housing to direct the stream of airflow to a nozzle at the end of the blower tube such that the airflow is forced out of the nozzle at a relatively high speed. The length of the blower tube typically allows a user to stand and hold the blower while positioning the nozzle near the debris to be cleared. In addition, the nozzle outlet opening is typically smaller than the outlet of the housing to increase the velocity of the airflow as the airflow stream is forced through the nozzle outlet opening.

SUMMARY

According to embodiments disclosed herein, a blower may include housing, a fan positioned within the housing, the fan having a fan edge. The blower may also include a fan housing section encircling the fan, the fan housing section having an inner surface that spans an inner circumference of the fan housing section, the inner surface having a plurality of indentations and being spaced within a certain distance from the fan edge.

According to embodiments disclosed herein, an axial blower may include a housing having a indented section, the indented section having a circular cross section and a plurality of indentations. The axial blower may also include a motor having a drive shaft housed in the housing and a fan attached to the drive shaft and being positioned in-line with the motor, the fan having a fan edge and being positioned within the indented section of the housing, a gap between the fan edge and the indented section being smaller than a certain size, the plurality of indentations increasing turbulence in airflow around the fan edge.

According to embodiments disclosed herein, a blower may include a housing having a fan section, the housing extending along a first direction and a motor housed in the housing, the motor having a drive shaft. The blower may also include a centrifugal fan attached to the drive shaft and being positioned to generate airflow in the first direction, the fan having a fan edge and being positioned within the fan section of the housing, the fan section having an inner surface that extends at least partially around the fan, in which a gap between the fan edge and the inner surface of portions of the fan section is within a certain gap size, and in which the inner surface of the fan section includes a plurality of curved indentations to create increased turbulence around the curved indentations as the motor rotates the fan.

DETAILED DESCRIPTION

Blowers may include a fan (or equivalently, an impeller) that rotates within a housing to generate airflow from an upstream side of the fan to a downstream side of the fan. Reverse airflow (or backflow) may also be generated as the fan rotates, in which the reverse airflow is airflow that flows from the downstream side of the fan to the upstream side of the fan through a gap between the outer edge of the fan and an interior surface of the housing. The velocity of the airflow flowing in the downstream direction may be decreased by streams of airflow flowing in the upstream direction. Thus, for instance, by reducing the size of the gap between the outer edge of the fan and the interior surface of the housing, the generated airflow may be improved. However, designing the axial blowers such that the gaps between the fans and the housing sections to be relatively small, e.g., less than about 1.5 mm, may cause manufacturing tolerances to be maintained at a high level to prevent, for instance, contact between the outer edges of the fans and the housing sections. Moreover, maintaining the manufacturing tolerances at the high level may increase costs associated with fabricating the axial blowers.

Disclosed herein are blowers having indentations formed in fan housing sections around fans of the blowers that may effectively decrease the size of the gaps between the fans and the interior surfaces of the housings. That is, as air flows into and around the indentations, turbulent airflow may be generated within the indentations and the turbulent airflow may form an airflow barrier, which may effectively reduce the sizes of the gaps between the outer edges of the fans and the interior surfaces of the housings. In this regard, the blowers disclosed herein may be fabricated with relatively lower manufacturing tolerances while still achieving a high level of airflow velocity and flow characteristics.

In the blowers disclosed herein, the indentations may be formed around the entire interior surfaces of the fan housing sections that encircle the fans, for instance, to minimize backflow of air through the fan housing sections in the blowers. The indentations may additionally be provided in other areas of the blower, for instance, those areas of the blower that may experience or may be predicted to experience turbulent flow. In this regard, the indentations may improve the flow of air through the blower in addition to increasing the velocity at which air flows through the axial blower.

The indentations may have dimensions and may be spaced at certain distances with respect to each other to maximize the improvement in the airflow and/or the increase in airflow speed. In some examples, the indentations may have the same sizes and/or may be spaced apart at the same distances with respect to each other. In other examples, some of the indentations may have different sizes as compared with other indentations and/or may be spaced apart at different distances with respect to other indentations. In addition, or in other examples, the indentations may be arranged in a repeating pattern, a random pattern, in aligned configurations, or the like. The sizes and placements of the indentations in an blower may be determined through testing, simulations, etc.

Before continuing, it is noted that as used herein, the terms “includes” and “including” mean, but are not limited to, “includes” or “including” and “includes at least” or “including at least.” The term “based on” means, but is not limited to, “based on” and “based at least in part on.”

Reference is first made toFIGS. 1A and 1B.FIG. 1Ashows a perspective view of a blower100according to an embodiment of the present disclosure.FIG. 1Bshows a cross-sectional side view of the blower100taken along lines A-A inFIG. 1A. It should be understood that the blower100, which is also referenced herein as an axial blower100or an apparatus100, depicted inFIGS. 1A and 1Bmay include additional components and that some of the components described herein may be removed and/or modified without departing from a scope of the blower100disclosed herein.

As shown inFIGS. 1A and 1B, the blower100includes a housing102and a blower tube140attached to the housing102. The housing102may be formed of a first part106and a second part108, in which the second part108may have a configuration that is a mirror image of the first part106. The first part106may be attached to the second part108via mechanical fasteners provided through aligned holes110formed on the first part106and the second part108. Alternatively, the first part106may be attached to the second part108via adhesives, mating components, combinations thereof, or the like. The housing102may also be formed of plastic, metal, combinations thereof, or the like.

In any event, the first part106and the second part108may include concave shapes such that when the first part106is attached to the second part108, a chamber112is formed in the interior of the housing102.FIG. 1Bdepicts the blower100with the second part108removed such that an interior of the housing102may be visible. As shown inFIG. 1B, a fan114and a motor116are positioned within the chamber112formed in the housing102. Particularly, the fan114is depicted as being attached to a drive shaft118of the motor116in an in-line arrangement with the motor116. That is, the motor116is depicted as being positioned downstream of the airflow direction generated by the fan114. In addition, the housing102is depicted as extending along a relatively straight line with the motor116and the fan114. Alternatively, the motor116may be positioned upstream of the airflow direction generated by the fan114. As the fan114and the motor116may be in-line with respect to each other in the direction of airflow, the blower100may be an axial blower.

The housing102may also include a handle120that an operator may grasp, for instance, to carry the blower100and to also control operation of the motor116and thus the fan114. The handle120may be integrally formed with the housing102as shown inFIGS. 1A and 1Bor may be mounted to the housing102via mechanical fasteners, adhesive, or the like. The handle120may extend at an angle with respect to the housing102such that a space122may be formed between the handle120and the housing102. In addition, a switch124may be provided on the handle120at a location that may be convenient for an operator to actuate the switch124with an operator's finger.

As also shown inFIGS. 1A and 1B, the handle120may include a battery support section126to support a battery128. The battery support section126may include a slot into which the battery128may be inserted and held in place with respect to the handle120. The battery128may be fixedly attached to the battery support section126or may be removably attached to the battery support section126. That is, in some examples, the battery128may be a removable battery while in other examples, the battery128may be integrated with the handle120and/or more generally, the housing102. In addition, or in other examples, the battery128may be a rechargeable battery.

In operation, actuation of the switch122may control delivery of energy from the battery128to the motor116. For instance, depression of the switch124may cause energy to be delivered to the motor116from the battery128. In addition, delivery of energy to the motor116may cause the motor116to rotate, which may cause a drive shaft118of the motor116and the fan114to rotate. The fan114includes a plurality of blades such that as the fan114rotates, airflow is caused to be brought into the chamber112through inlet holes130of the housing102. In addition, rotation of the fan114causes airflow to be forced out of the housing102through an outlet opening132of the housing102, as represented by the arrow134.

As also shown inFIG. 1B, the housing102may also include a fan housing section136encircling the fan114, in which the fan housing section136includes a plurality of indentations138, which are also referenced herein as curved indentations or dimples138. The plurality of indentations138may span across an entire inner circumference of the fan housing section136, which is also referenced herein as an indented section136or a fan section136. As shown, the fan housing section136may include a portion of the housing102that is adjacent to the outer edge (also referenced herein as a fan edge) of the fan114, e.g., adjacent to the outer edges of the fan114blades. In addition, the fan housing section136may extend across a width that is substantially greater than a width of the fan114. For instance, the fan housing section136may extend at least 0.5 inch on either side of the fan114. In other examples, the indentations138may be provided at a relatively larger interior surface area of the housing102, e.g., throughout the interior surface of the housing102. In particular examples, the indentations138may be provided at areas of the interior surface at which turbulent airflow occurs. Moreover, the fan housing section136may be located at a relatively short distance from the outer edge of the fan114. As discussed in greater detail herein, the indentations138in the fan housing section136may increase turbulence of airflow around the outer edges of the fan114as compared with configurations in which the indentations138are omitted.

The blower100is also depicted as including a blower tube140attached to the outlet opening132of housing102. The blower tube140may be attached to the housing102through a suitable attachment mechanism. For instance, the blower tube140may be attached to the housing102via mechanical fasteners, via an adhesive, via physical mating elements, e.g., tongue-and-groove elements, via friction fit, or the like. Alternatively, a segment146of the blower tube140may integrally be formed with the housing102. In any regard, the blower tube140may have a tapered configuration in which a first end142of the blower tube140that is attached to the housing102has a larger diameter than a second end144of the blower tube140that is located distally from the first end142. The blower tube140may also be formed of multiple converging segments146-150that may be arranged in a telescoping configuration with respect to each other. That is, a third segment150may be insertable into a second segment148and the second and third segments148,150may be insertable into a first segment146to reduce a size of the blower tube140. In other examples, however, the blower tube140may be formed of a single segment. According to examples, the blower tube140may have a length that may enable the second end144to be located near the ground when an operator holds the blower100.

According to the embodiment shown inFIG. 1B, a cone152may be provided on the motor116downstream of the fan114. The cone152may improve airflow through the blower tube140, which may increase the velocity of airflow expelled through the blower tube140, for instance, by reducing recirculation of airflow into the motor116. In addition, or in other examples, at least a portion of the interior surface of the blower tube140may be provided with indentations138. For instance, portions of or the entire interior surface of the blower tube140may be provided with indentations138. Moreover, indentations138may also be provided on surfaces of the motor116, the cone152, the fan114, as well as other surfaces in the interior of the blower100over which air may flow.

Turning now toFIG. 2, there is shown a cross-sectional perspective view of a portion of the blower100depicted inFIGS. 1A and 1B. As shown inFIG. 2, the fan114is depicted as including a plurality of blades202extending from a hub204that is attached to the drive shaft118. In addition, wiring206is depicted as connecting the battery128with the motor116and an actuator208of the switch124. Moreover, in the embodiment shown inFIG. 2, the cone152is not depicted as being positioned on the motor116.

Reference is now made toFIG. 3, which depicts an enlarged view of a portion of the fan housing section136and the fan114shown inFIGS. 1B and 2. As shown inFIG. 3, the fan housing section136may include a plurality of indentations138arranged in a pattern across in inner area of the fan housing section136. In operation, as the fan114rotates, air may flow from a downstream part300of the fan114back around to an upstream part302of the fan114through a gap304between an outer edge306of the fan114and the wall308of the fan housing section136. The wall (inner surface)308of the fan housing section136may be within a certain distance of the outer edge306of the fan114around the periphery of the wall308. For instance, the fan edge306is an extent to which the fan114extends from a center of the fan114, in which the inner surface308of the fan housing section136extends about a center of the fan housing section136, and in which the center of the fan114is collocated with the center of the fan housing section136. By way of particular example, the distance between the outer edge306of the fan114and the wall308of the fan housing section136may be between about 0.5 mm and about 5 mm. In one embodiment, the distance between the fan114and the wall308of the fan housing section136is about 1.5 mm.

As represented by the arrows310, the indentations138may cause turbulence of the airflow in the indentations138generated through rotation of the fan114. The turbulence310may result in a gap312between the outer edge306of the fan114and an effective edge314formed by the turbulence310to be smaller than the gap304between the outer edge306of the fan114and the wall308of the fan housing section136. The smaller gap312may reduce the amount of air flowing back from the downstream part300to the upstream part302of the fan114. The reduction in the reverse flow of the air may result in an increase in efficiency in the generation of airflow by the fan114. In addition, the increase in efficiency may result in an improvement in the airflow and/or increase In the airflow speed.

The inclusion of the indentations138may also enable manufacturing tolerances to be relatively higher while still providing the increased airflow. That is, through the indentations138, the fan114and the wall308of the fan housing section136may be fabricated to have a relatively larger gap304while still providing the increased airflow, which may reduce manufacturing costs associated with the blower100.

As shown inFIG. 3, the indentations138may not extend through the fan housing section136, e.g., the indentations138may not include holes through which air may flow. Instead, the indentations138are depicted as each being formed of spherical indentations or curved depressions that are spaced from neighboring indentations138by certain distances. According to examples, the dimensions of the indentations138and the spacings of the indentations138with respect to each other may strategically be selected to improve airflow (e.g., less turbulent flow) and/or increase airflow speed. Thus, for instance, the dimensions and the spacings of the indentations138may be selected based upon the configuration and operation of the fan114and may vary for different114and motor116combinations. The dimensions of the indentations138may include the radius of curvatures, the depths, the widths, combinations thereof, or the like.

According to examples, each of the indentations138may have the same dimensions and may be spaced apart from neighboring indentations138by the same distances with respect to each other. By way of particular example, the indentations138may each have a radius of curvature of between around 1 mm and around 10 mm. In addition or in other examples, the indentations138may be spaced apart from each other by distances of between around 1 mm and around 10 mm. In other examples, some of the indentations138may have different sizes with respect to each other and/or some of the indentations138may be spaced apart from each other by different distances with respect to each other. An example of a fan housing section136having indentations138of different sizes with respect to each other is shown inFIG. 4. Particularly,FIG. 4shows a perspective view of a fan housing section136having indentations400having a first size and indentations402having a second size.

As also shown inFIG. 3, the indentations138may be arranged in aligned columns and rows across the inner area of the fan housing section136. In other examples, the indentations138may be arranged in other patterns, e.g., in random locations, in a regular repeating pattern, in an irregular repeating pattern, combinations thereof, or the like. An example of a fan housing section136having indentations138arranged in a different pattern from that shown inFIG. 3is shown inFIG. 5. Particularly,FIG. 5shows a perspective view of a fan housing section136having indentations138that are arranged in a helical configuration with respect to each other.

According to examples, the fan housing section136is formed in areas of the first part106and the second part108of the housing102. In these examples, the indentations138may be formed into the interior surfaces of areas of the first part106and the second part108of the housing102. Thus, for instance, the indentations138may be formed into the first part106and the second part108during fabrication of the first part106and the second part108, for instance, through molding. In other examples, the fan housing section136is formed as an insert that is separate from the housing102. In these examples, the fan housing section136may be formed as a cylindrical collar that may be inserted in an interior area formed through attachment of the first part106to the second part108of the housing102. In addition, the fan housing section136may be formed of plastic, metal, ceramic, an alloy, combinations thereof, or the like through any suitable fabrication technique.

Reference is now made toFIGS. 6A-6D, which respectively show diagrams of a blower600according to another embodiment of the present disclosure. Particularly,FIG. 6Ashows a side view of the blower600,FIG. 6Bshows a cross-sectional perspective view of the blower600,FIG. 6Cshows a cross-sectional side view of a section of the blower600, andFIG. 6Dshows a cross-sectional top view of the blower600taken along lines B-B inFIG. 6A. It should be understood that the blower600, which is also referenced herein as a centrifugal blower600or an apparatus600, depicted inFIGS. 6A-6Dmay include additional components and that some of the components described herein may be removed and/or modified without departing from a scope of the blower600disclosed herein.

As shown inFIGS. 6A-6D, the blower600includes a housing602that may be formed of a first part606and a second part608, in which the second part608may have a configuration that is a mirror image of the first part606. The first part606may be attached to the second part608via mechanical fasteners provided through aligned holes610formed on the first part606and the second part608. Alternatively, the first part606may be attached to the second part608via adhesives, mating components, combinations thereof, or the like. The housing602may also be formed of plastic, metal, combinations thereof, or the like.

In any event, the first part606and the second part608may include concave shapes such that when the first part606is attached to the second part608, a chamber612is formed in the interior of the housing602.FIGS. 6B and 6Cdepict the blower600with the second part608removed such that an interior of the housing602may be visible. As shown inFIGS. 6B and 6C, a fan614and a motor616are positioned within the chamber612formed in the housing602. Particularly, the fan614may be attached to a drive shaft (not shown) of the motor616. In addition, the motor616is depicted as being positioned at an angle, e.g., perpendicularly, with respect to the direction in which the fan614generates airflow. That is, the fan614includes blades618that are to generate airflow in the direction denoted by the arrow620. As the motor616may not be located in the in line with the fan614in the direction of airflow620, the blower600may be a centrifugal blower.

The housing602may also include a handle622that an operator may grasp, for instance, to carry the blower600and to also control operation of the motor616and thus the fan614. The handle622may be integrally formed with the housing602as shown inFIGS. 6A and 6Bor may be mounted to the housing602via mechanical fasteners, adhesive, or the like. The handle622may extend at an angle with respect to the housing602such that a space624may be formed between the handle622and the housing602. In addition, a switch626may be provided on the handle620at a location that may be convenient for an operator to actuate the switch626with an operator's finger.

As also shown inFIGS. 6A and 6B, the handle622may include a battery support section628to support a battery (not shown). The battery support section628may include a slot into which a battery may be inserted and held in place with respect to the handle622. The battery may be fixedly attached to the battery support section628or may be removably attached to the battery support section628. That is, in some examples, the battery may be a removable battery while in other examples, the battery may be integrated with the handle620and/or more generally, the housing602. In addition, or in other examples, the battery may be a rechargeable battery.

In operation, actuation of the switch626may control delivery of energy from the battery to the motor616. For instance, depression of the switch626may cause energy to be delivered to the motor616from the battery. In addition, delivery of energy to the motor616may cause the motor616to rotate, which may cause a drive shaft of the motor616and the fan614to rotate. The fan614includes a plurality of blades618such that as the fan614rotates, airflow is caused to be brought into the chamber612through inlet holes630of the housing602. In addition, rotation of the fan614causes airflow to be forced out of the housing602through an outlet opening632of the housing602.

As also shown inFIGS. 6B-6D, the housing602may also include a fan housing section636at least partially encircling the fan614, in which the fan housing section636includes a plurality of indentations638, which are also referenced herein as curved indentations or dimples638. The plurality of indentations638may span across an entire inner surface of the fan housing section636, which is also referenced herein as an indented section636or a fan section636. In other examples, the indentations638may extend for a portion of the fan housing section636, e.g., in the portions of the fan housing section636that are immediately adjacent to the fan614. By way of particular example, the distance between the outer edge640of the fan614and portions of a wall of the fan housing section636may be between about 0.5 mm and about 5 mm. In one embodiment, the distance between the outer edge640of the fan614and a wall of the fan housing section636is about 1.5 mm.

As shown, the fan housing section636may include a portion of the housing602that is adjacent to an outer edge640(also referenced herein as a fan edge) of the fan614, e.g., adjacent to the outer edges640of the fan614blades618. In addition, the fan housing section636may extend across a height that is substantially greater than a height of the fan614. For instance, the fan housing section636may extend at least 0.5 inch above and below the fan614.

In other examples, the indentations638may be provided at a relatively larger interior surface area of the housing602, e.g., throughout the interior surface of the housing602over which air is to flow. In particular examples, the indentations638may be provided at areas of the interior surface at which turbulent airflow occurs. Moreover, portions of the fan housing section636may be located at a relatively short distance from the outer edge of the fan614as shown inFIG. 6D. As discussed in greater detail herein, the indentations638in the fan housing section636may increase turbulence of airflow around the outer edges640of the fan614as compared with configurations in which the indentations638are omitted.

The indentations638may be similar to the indentations138discussed above with respect toFIGS. 1A-5. In this regard, for instance, the indentations638may each have a radius of curvature of between around 1 mm and around 10 mm. In addition or in other examples, the indentations638may be spaced apart from each other by distances of between around 1 mm and around 10 mm. In other examples, some of the indentations638may have different sizes with respect to each other and/or some of the indentations638may be spaced apart from each other by different distances with respect to each other, for instance, as shown inFIG. 4. Additionally, the indentations638may be formed in an interior surface of the housing602or in an insert that may be inserted into the housing602.

Although not shown, the blower600may also include a blower tube attached to the outlet opening632of housing602. The blower tube may be similar to the blower tube140shown inFIGS. 1A and 1Band may be attached to the housing602in any of the manners discussed above.