JP2008045557A - Fan-motor assembly insert - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fan insert achieving improved efficiency. <P>SOLUTION: A fan assembly includes an end bracket to be connected to a motor assembly. The end bracket includes a peripheral passage interrupted by an opening. A fan including a plurality of blades is provided. A shroud encircles at least part of the fan to define a chamber. An insert which can be formed to be or not to be integral part of the end bracket is stored in the chamber. The insert includes a peripheral ramp. The peripheral ramp is shaped to serve the peripheral passage as a passage having an internal cross section changed along the peripheral passage to improve the efficiency of an air flow. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention generally relates to motor assemblies. In particular, the present invention relates to fan inserts for shrouded fan-motor assemblies that increase motor efficiency and air flow characteristics. More particularly, the present invention relates to an insert that is housed in a cavity created by a fan end bracket and a shroud and can be adapted to existing designs.

  Vacuum motors using tangential bypass are used in many applications, vacuum manipulators, packaging equipment, bag filling, cutting tables, appliances, and exhaust air removal, to name a few. Such vacuum motors generally include a cylindrical shape or shroud that encloses a motor driven fan that rotates about an axis. Air is drawn into the housing through an axial hole in the top center of the housing above the fan. As the fan rotates, air is accelerated in the surrounding and radially outward direction. The housing includes an outlet located on the side of the fan opposite the axial bore. The outlet is a generally cylindrical opening disposed tangentially on the radially outer edge of the housing so that air traveling tangentially along the radially outer edge of the housing is tangentially through the outlet. Is discharged. Such fans are efficient and have a small profile that allows them to be installed in devices that require thin fan-motor assemblies.

  As is the case for many fan designs, efficiency is an important concern. However, current housing designs do not direct air flow into the most efficient passage of air flow within the housing. More particularly, it is believed that undesired turbulence and dead zones occur due to the uncontrolled air flow path from where air is exhausted from the rotating fan to where the air leaves the outlet. Fans cause significant kinetic energy in the air by imparting a tangential velocity to the air. The air must be decelerated in a controlled manner to convert kinetic energy back into pressure. Sudden changes in cross-sectional area create vortices and turbulence, which dissipate heat as heat without restoring kinetic energy to its pressure. The total pressure (or vacuum) created by the motor / fan assembly is therefore adversely affected by allowing air to leave the fan uncontrolled. Therefore, better air flow needs to be controlled to achieve greater fan efficiency. Furthermore, such an improvement must be applicable not only to a new fan assembly but also to an already installed fan assembly. This is because the manufacturer does not want to change the existing molding machinery.

  Accordingly, there is a need in the art for an insert that can be attached to a fan housing of a vacuum motor that uses a tangential bypass and that controls air flow to increase efficiency.

  In view of the foregoing, it is an object of the present invention to provide a fan insert that achieves improved efficiency.

According to one aspect of the invention, in a fan assembly,
An end bracket coupled to the motor assembly, the end bracket including a circumferential passage interrupted by the opening;
At least one fan containing a plurality of blades;
A shroud that at least partially surrounds the fan to define a chamber;
An insert housed in the chamber, the insert including a circumferential ramp housed in the chamber;
And a fan assembly is provided, wherein the circumferential ramp is shaped such that the circumferential passage is a passage having a cross-sectional area that varies circumferentially.

According to another aspect of the invention, in a fan assembly,
A unitary end bracket and insert that is generally cylindrical and has a central axis, wherein the insert includes a circumferential ramp disposed in a helical orientation with respect to the central axis, and Inserts,
A shroud coupled to the end bracket and defining a chamber between the end bracket;
A fan selectively rotatable by a shaft, the fan being disposed in the chamber and generating a flow of air energized along the circumferential ramp;
A fan assembly is provided.

  For a full understanding of the objects, techniques, and configurations of the present invention, reference is now made to the following detailed description and accompanying drawings.

  A fan insert according to the inventive concept, indicated generally by the reference numeral 80 in the accompanying drawings, is used in conjunction with a motor / fan assembly, indicated generally by the reference numeral 10 in the accompanying drawings. Since the insert 80 can be used in connection with many other similarly configured motor / fan assemblies, only general descriptions of components other than those of the fan / motor assembly that are directly associated with the insert 80 are provided below. It shall be described in

  As best shown in FIGS. 1 and 2, the motor / fan assembly 10 of the present invention includes a motor subassembly 11 and a fan subassembly 12. It should be appreciated that, except for the fan end bracket, which is generally indicated by reference numeral 21 and will be described in detail later, the motor subassembly 11 can be of any suitable general configuration. In one particular embodiment, motor subassembly 11 includes a housing 13. The housing 13 can carry a concentrically arranged bearing 14 that receives the shaft 15 therein. The shaft 15 supports the armature 16 and the commutator 17 on the outer periphery thereof. The shaft 15 further carries a cooling fan 18, and the cooling fan 18 is disposed at the end of the shaft 15 opposite to the fan subassembly 12. The cooling fan 18 creates a flow of air across the internal motor components and facilitates heat dissipation. The motor subassembly further includes a plurality of magnetic field coils 19 and a plurality of brushes 20. As is known in the art, these motor components interact to cause the shaft 15 to selectively rotate. As will be described later, the shaft 15 drives the working parts of the fan subassembly.

  In one embodiment, the end bracket 21 is provided at the end of the motor subassembly 11 opposite to the housing 13. End bracket 21 can be generally circular and is provided to allow fan components to be coupled to the motor subassembly. Additionally, the end bracket 21 seals the motor subassembly 11 by sealing around the shaft 15 so that the air flow generated by the fan subassembly 12 is not contaminated by air or other material from the motor subassembly 11. Separate from the fan subassembly 12. The end bracket 21 can be provided with a plurality of ears or notches 23 by which the associated device can be secured by the end-use manufacturer in a selected position therefor. End bracket 21 includes an outer flange 24 that defines its radially outer surface. The outer flange 24 may be provided with a raised shoulder 25 that projects radially from the flange 24 and around the circumference of the outer flange 24. The raised shoulder 25 is provided as a stopper, and the rim of the shroud 26 is seated on the stopper. In this manner, the shroud 26 is received around the outer flange 24 to form a substantially hermetic seal. As will be described in detail later, the shroud 26 cooperates with the end bracket 21 to form a first chamber 27 that receives several fan operating components.

  The end bracket 21 is further provided with an inner plate 28. The inner plate 28 is substantially circular and extends in the radial direction so as to face the first chamber 27. The inner plate 28 ends at its radially outer edge with an inner flange 29 that extends perpendicularly from the inner plate 28. The inner flange 29 also extends beyond the inner plate 28 and includes a shoulder 30 that can support the insert 80 as described below. Inner flange 29 and outer flange 24 form two generally opposed outer walls of circumferential passage 31.

  The passage 31 is annular in shape and has a generally U-shaped cross section with a bottom surface 32 and opposite side walls defined by the flanges 24 and 29. A pair of curved edges 33 can be provided at the transition between the bottom surface 32 and the flanges 24 and 29. The inner plate 28 also includes a shaft hole 33 that passes through the inner plate 28. The passage 31 is interrupted over a portion of its outer periphery and extends into the opening 41 (best seen in FIG. 4). The opening 41 is formed by a tangential horn 42, which can be integrally formed with the end bracket 21 or can be made separately from the end bracket 21 and attached to extend from the end bracket 21. The horn 42 preferably extends beyond the outer flange 24 and terminates in a tubular portion 43 that can receive a discharge hose for the working air driven through the fan subassembly 12.

  The inner flange 29 and the inner plate 28 serve as a common wall between the fan subassembly 12 and the motor subassembly 11, and a common shaft 15 extends through the common wall and is operatively connected to the motor operating components described above. Is done. Accordingly, a support ring 45 facing the motor subassembly 11 is provided in the center of the inner plate 28 around the shaft hole 33, both the support ring 45 and the shaft hole 33 being adapted to receive a bearing 46 therein. The bearing 46 is adapted to receive and support the rotating shaft 15 therein. The support ring 45 also extends axially from the inner plate 28 to define a boss 47 that extends into the first chamber 27. A seal 48 may be provided between the bearing 46 and the support ring 45 and / or boss 47 to prevent contamination of air passing through the fan subassembly. The seal 48 can be of any shape. In fact, such seals utilize the teachings of US Pat. Nos. 5,482,378 and 6,472,786, both of which are described by reference.

  The fan end bracket 21 is further provided with a plurality of alignment tabs 50 that are spaced circumferentially and extend radially inward from the outer flange 24 into the passage 31. Yes. Furthermore, the inner plate 28 can be provided with a plurality of holes 51, each of which receives a fixing means. In this embodiment, the fixing means is shown as a screw 52. However, other securing means such as rivets, adhesives, snap fittings, clips, deformable tabs, and frictional couplings can be used. As will be described more fully below, tabs 50 and holes 51 are provided for aligning and securing the insert 80 within the first chamber 27.

  The shroud 26 is provided with a port 60 that is substantially concentric with the shaft 15. This port 60 is provided to allow working air to enter the fan subassembly 12. The shroud 26 surrounds at least one or more rotary centrifugal fans 61, and the fans 61 are close to the bearings 46. The fan 61 comprises a plurality of relatively short radial blades 62 attached to a disk 63. The disk 63 has a central hole that allows the fan 61 to be attached to the shaft 15. The disk 63 abuts on a first centrifugal air fan 64 having a plurality of blades 65 extending radially outward and rotates together with the fan 64. The blade 65 is held between a disk 66 and a ring 99, which has a central hole that allows the first working fan 64 to be attached to the shaft 15. Ring 99 has an air flow hole 100 extending therethrough. If an air seal arrangement is used, then the disc 66 is one or more circumferentially spaced with respect to the shaft, as disclosed in the aforementioned US Pat. No. 5,482,378. The above holes can be provided. These holes serve to absorb moisture from the bearing 46 so that moisture is drawn into and discharged from the working air stream.

  In the illustrated embodiment, the shroud 26 surrounds not only the fans 61 and 64 but also an additional fan that draws working air into the fan subassembly 12. This multi-stage embodiment is possible by providing the shroud 26 with a dividing wall 67 extending radially inward from the radially outer wall of the shroud 26. The dividing wall 67 is provided with an opening 68 that communicates with the air flow hole 100 of the operating fan 64. In this way, the dividing wall 67 separates the interior of the fan subassembly into a first chamber 27 and a second chamber 69. The dividing wall 67 supports the stationary blade 70 extending in the radial direction of the intermediate “fixed fan” 71 outside the opening 68 in the radial direction. The second centrifugal fan 72 is provided close to the port 60 and includes a plurality of blades 73 extending in the radial direction. These blades 73 are carried between the disk 74 and the ring 104. The disc 74 has a central hole that allows the fan 72 to be attached to the shaft 15. The ring 104 has an eye 106 that is substantially concentric with the port 60 of the shroud 26. Although a multi-stage fan is shown in this embodiment, the insert described below is a single-stage fan or any arrangement that receives air axially and then exhausts air tangentially, or vice versa. It will be appreciated that they can be used together.

  In the present embodiment, the plurality of fans 61, 64, 72 described above are spaced apart from each other and connected to the shaft 15 by a plurality of elements. That is, the first spacer 75 extends inward through the shaft hole 33 of the support ring 45 and abuts against the inner race of the bearing 46. The first spacer 75 can have a generally L-shaped cross-section, thereby providing an enlarged lateral surface against which the disk 63 of the fan 61 can abut. A second spacer 76 is provided between the working air fans 64 and 72, and the second spacer 76 is fitted around the shaft 15. The second spacer 76 may have a generally drum shape in the radial cross section. A nut 77 can be attached to the end of the shaft 15, and the nut 77 is tightened against the washer 78, and then the washer 78 abuts against the disk 74 of the fan 72. This then clamps the inner race of the bearing 46, the first spacer 75, the second spacer 76, the fans 61, 64, 72 and the washer 78 together so that all of these are When driven by the motor subassembly 11, it rotates as a unit together with the shaft 15.

  In the configuration described above, when the shaft 15 rotates, air is sucked into the second chamber 69 through the port 60. More specifically, as the second working air fan 72 rotates, air is drawn through the eye 106 and urged radially outward by the blades 73. When air is released radially outward past the blade 73, the blade 70 of the stationary fan 71 directs the air radially inward toward the opening 68. As is apparent from FIG. 2, the opening 68 directs air flow through the air flow hole 100 into the first chamber 27. As the fan 64 rotates, the blade 65 urges air radially outward. The air flow discharged radially from the blade 65 has two components, radial and tangential. In other words, the air particles travel radially outward and simultaneously rotate with the fan 64. Therefore, when the air exits the fan 64, if the fan 64 advances in the counterclockwise direction (in the present embodiment, the counterclockwise direction), the air correspondingly counteracts around the chamber 27 and the passage 31. Proceed clockwise in the circumferential direction. Due to the pressure difference between the outer atmosphere and the first chamber 27, the air exits the chamber 27 and the passage 31 through the opening 41. Therefore, as described above, air is sucked into the port 60 by the rotation of the shaft 15 and then discharged from the tubular portion 43. Such a system is particularly useful for general household appliance vacuums, but can also find applications in many other areas. Although the design described above works well for many applications, there is always a desire to increase the efficiency of such devices. In particular, it has been found that the air flow in the passage 31 results in a loss of efficiency as described in the background section above. In order to increase efficiency, an insert 80 is provided to guide the air flow after it exits the fan 64. The insert 80 can be pre-mounted on the motor / fan assembly, or it can be mounted in post-sales specifications due to its compact and simple design. Alternatively, the insert 80 and end bracket 21 may be formed as a single piece and combined with the motor and fan subassemblies in much the same manner as the separate insert 80 and end bracket 21 described above. Regardless of whether the insert 80 is made as a separate piece or as a single piece integral with the end bracket 21, the seal 48 or equivalent means to ensure that moisture is kept away from the bearing 46. Is provided.

  The insert 80 is generally cup shaped and includes a face wall 81 that is disk shaped and centered around the shaft 15.

  The face wall 81 is sized to cover the inner plate 28 in accordance with the size of the inner plate 28 when attached. A taper boss 82 is provided, and the taper boss 82 is raised to allow the boss 47 to be fitted on the lower side thereof. The taper boss 82 protrudes from the concentric center portion of the face wall 81 toward the fan 64 and includes a hole 83, which allows the shaft 15 to protrude through the hole 83. The face wall 81 further includes a plurality of counterbore holes 84, each of which is adapted to receive a screw 52 through each counterbore 84. When assembled, the threaded portion of the screw 52 passes through the face wall 81 and protrudes into the hole 51 provided in the inner plate 28. Furthermore, the head of the screw 52 is received in the counterbore portion of the hole 84 so that no portion of the screw 52 extends over the surface of the face wall 81. By this method, when the screw 52 is tightened, the insert 80 is fixed to the end bracket 21.

  The face wall 81 ends with a circumferential flange 85 that extends axially inward from the radial edge of the face wall 81 toward the end bracket 21. The circumferential flange 85 is sized to fit around the inner flange 29. A lamp 86 is provided on the radially outer surface of the circumferentially attached portion 85. The ramp 86 is adapted to be received in the passage 31 and is shaped to define a gradually changing depth in the circumferential direction. For this purpose, the ramp 86 includes an angled inclined wall 87 that extends radially from the circumferential flange 85 toward the outer flange 24 of the end bracket 21. The inclined wall 87 is provided obliquely with respect to the bottom surface 32 of the passage 31, so that when the inclined wall 87 is provided around the face wall 81, the inclined wall 87 defines an upper end 88 and a lower end 89. Alternatively, the inclined wall 87 is provided in a spiral shape around the face wall 81. The upper end 88 is provided far from the bottom surface 32 of the passage 31 compared to the lower end 89 proximate to the bottom surface 32 of the passage 31. In the present embodiment, the lower end 89 is generally flush with the bottom surface 32. Although this embodiment discloses an inclined wall 87 having a constant angle with respect to the bottom surface 32, it should be recognized that this disclosure is not limited to such an embodiment. That is, the relative angle can change in the circumferential direction in a straight line or logarithmic manner.

  The inclined wall 87 is further supported by a pair of legs ending in the passage 31. That is, the inner leg 90 is provided at the radially inner edge of the inclined wall 87 and extends in the axial direction toward the bottom surface 32 of the passage 31. Further, an outer leg 91 is provided at the radially outer edge of the inclined wall 87 and extends toward the bottom surface of the passage 31. Each leg is provided with a bent end 92, and these bent ends 92 are made to substantially coincide with the bent corner portion of the passage 31. As is apparent from FIG. 6, the heights of the legs 90 and 91 change in the circumferential direction. More specifically, where the inclined wall 87 is located close to the bottom surface 32, the legs 90 and 91 are correspondingly lower in height, and conversely, the inclined wall 87 is far away from the bottom surface 32. In the part where it is arranged, the height of the legs 90 and 91 is correspondingly high.

  An end wall 93 is provided in the vicinity of the upper end 88, and this end wall 93 extends downward from the inclined wall 87 toward the bottom surface 32 of the passage 31. When properly aligned, the end wall 93 can be disposed at an angle substantially parallel to the horn 42. In order to maintain proper alignment of the insert 80 in proper alignment, the outer leg 91 includes a plurality of slots 94 that are slidably received on the tabs 50 of the end bracket 21. Finally, the insert 80 includes a protrusion 95 that extends a certain distance along the radially outer edge of the inclined wall 87, starting from the upper end 88 and extending circumferentially. The protrusion 95 limits the cross section at the upper end of the lamp. This helps to control the deceleration of the air exhaust fan 64 and also helps to induce more air at the bottom of the lamp to exhaust air through the horn 42 rather than continuously swirling through the shroud.

  As apparent from FIG. 5A, the taper ramp 86 does not extend around the entire circumference of the passage 31. When the taper ramp 86 is properly installed, this interruption of the taper ramp 86 is aligned with the interruption of the passage 31. In other words, the end wall 93 is positioned near the first end 108 of the opening 41 and the bottom end 89 of the inclined wall 87 is positioned near the second end 109 of the opening 41. In this way, the insert 80 is fixed to the end bracket 21 and, when correctly positioned, changes the shape and cross-sectional area of the passage 31 as a function of the circumferential position.

  When the shaft 15 rotates, therefore, when the working air fan 64 is driven, the air propelled from the blade 65 is directed to the opening 41 of the end bracket 21 more efficiently. More specifically, when the insert 80 is mounted as shown in this embodiment, the effective cross-sectional area of the passage 31 gradually increases starting from the upper end 88 in the counterclockwise direction. The effective cross-sectional area of the passage 31 is the largest at the interrupted portion of the insert 80 corresponding to the opening 41. By changing the effective cross-sectional area of the passage 31 in this way, the kinetic energy stored in the moving air is not a turbulent flow that causes heat due to the reduction of vortices as the air leaves the rotating fan. Can be converted to static pressure more completely.

  From the above description, the advantages of the above configuration will be readily apparent. That is, the insert 80 is structured to provide a more efficient passage for advancing air into the fan subassembly 12. More specifically, when the insert 80 is installed, fan efficiency is increased and therefore less energy is required to provide the same air flow. In addition, the insert 80 is structured so that it can be easily attached to a fan subassembly of an existing design and can be used in a single stage device or a multi-stage device (as in the embodiments described above). . Thus, the present invention described above provides a significant improvement in the field of fan assemblies.

  From the above description, it will be understood that the object of the present invention is achieved by the above-described configuration. Also, although only the preferred embodiments of the best mode of the present invention have been described in detail according to patent law, it will be understood that the present invention is not limited to or by such specific embodiments. Accordingly, reference should be made to the appended claims in order to recognize the true scope of the present invention.

1 is a perspective view of a fan / motor assembly made in accordance with the concepts of the present invention. FIG. 1 is a partial cross-sectional view of a fan / motor assembly made in accordance with the concepts of the present invention. FIG. FIG. 3 is an exploded view of an end bracket and insert made in accordance with the concepts of the present invention. It is a top view of an end bracket. It is a top view of the end bracket which has attached insert. It is a top view of insert. It is a perspective view of an insert which shows the underside of an insert. It is a perspective view of the end bracket which has attached insert.

Claims (19)

In the fan assembly,
An end bracket coupled to the motor assembly, the end bracket including a circumferential passage interrupted by the opening;
At least one fan containing a plurality of blades;
A shroud that at least partially surrounds the fan to define a chamber;
An insert housed in the chamber, the insert including a circumferential ramp housed in the chamber;
The fan assembly is configured such that the circumferential ramp is a passage having a circumferential cross section that changes the circumferential passage.   The fan assembly of claim 1, wherein the circumferential ramp includes an inclined surface, the chamber includes a bottom surface, and the inclined surface of the circumferential ramp is disposed at an angle with respect to a bottom direction of the chamber. Fan assembly.   3. The fan assembly according to claim 2, wherein the angle is constant in the circumferential direction.   3. The fan assembly according to claim 2, wherein the angle varies depending on a circumferential position.   The fan assembly according to claim 1, wherein the insert is disposed between the fan and the end bracket.   The fan assembly according to claim 1, wherein the circumferential ramp does not extend all around the chamber to define a gap, and the gap is circumferentially aligned with the opening.   7. The fan assembly of claim 6, wherein the circumferential passage includes a bottom surface, the circumferential ramp includes an upper end and a lower end, and the opening has a first end and a second end. The upper end is farther from the bottom surface than the lower end, the upper end is positioned near the first end, and the lower end is at the second end. A fan assembly located nearby.   2. The fan assembly of claim 1, wherein the circumferential passage includes at least one tab and the insert includes at least one slot adapted to receive the tab, thereby positioning the insert in the chamber. Fan assembly.   The fan assembly according to claim 1, further comprising a horn, said horn terminating in said opening and projecting tangentially from said opening with respect to said circumferential passage.   The fan assembly according to claim 1, wherein the cross-sectional area increases circumferentially in the direction of flow.   2. The fan assembly of claim 1, further comprising a rotatable shaft extending from the motor assembly, a bearing carried by the end bracket and receiving the rotatable shaft, the bearing and the end. A fan assembly including a seal disposed between the bracket. In the fan assembly,
A unitary end bracket and insert that is generally cylindrical and has a central axis, wherein the insert includes a circumferential ramp disposed in a helical orientation with respect to the central axis, and Inserts,
A shroud coupled to the end bracket and defining a chamber between the end bracket;
A fan selectively rotatable by a shaft, the fan being disposed in the chamber and generating a flow of air energized along the circumferential ramp;
Including the fan assembly.   13. A fan assembly according to claim 12, wherein the unitary end bracket and insert are disposed adjacent to the fan.   13. A fan assembly as claimed in claim 12, wherein the unitary end bracket and insert include a face wall that is circular and projects radially from the central axis, the circumferential ramp being on a radially outer edge of the face wall. A fan assembly disposed on the housing.   13. The fan assembly according to claim 12, wherein the circumferential ramp includes a first end and a second end, the first end being disposed farther from the fan than the second end. Fan assembly.   16. The fan assembly of claim 15, wherein a circumferential distance between the first end and the second end defines a gap, and the gap is aligned with the opening in the passage.   16. The fan assembly of claim 15, wherein the unitary end bracket and insert further includes a horn, the horn is in communication with the circumferential ramp and is aligned tangentially from the circumferential ramp. Protruding fan assembly.   18. The fan assembly according to claim 17, wherein the shroud has an inlet for sucking air by rotation of the fan, and the air is discharged along the circumferential ramp to be discharged out of the horn. assembly.   13. The fan assembly of claim 12, further comprising: a bearing carried by said single end bracket and insert and receiving said rotatable shaft; and said bearing and said single end bracket and insert. A fan assembly including a seal disposed therebetween.

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