Double inlet centrifugal blower with PCB center plate
10655640 ยท 2020-05-19
Assignee
Inventors
Cpc classification
F04D17/105
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/281
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/4206
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D25/0606
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D25/166
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/053
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D25/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/056
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D17/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/663
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D17/162
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/424
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D25/066
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F04D29/66
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D17/08
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/28
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/053
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D17/10
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D29/42
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F04D25/06
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
A centrifugal blower apparatus includes a scroll-shaped housing with first and second air inlets which open to a blower chamber that is in fluid communication with an air outlet. The blower includes a motor to drive impellers, wherein the motor is secured to a frame coupled within the housing in a manner to substantially enhance aerodynamic performance of the blower.
Claims
1. A centrifugal blower apparatus, comprising: a housing having air inlets formed in opposing sides of said housing and having air outlets formed in an open end of said housing, wherein said air inlets and said air outlets are in fluid communication with a blower chamber within said housing; a motor support that divides said blower chamber into at least a first and second sub-chamber, said motor support having at least one aperture formed through a central portion of said motor support, said at least one aperture being at least one of: circular or oval, said at least one aperture being adapted to receive a motor support sleeve, said motor support sleeve being at least one of: circular or oval, said motor support sleeve having an internal radial plane, said motor support being constructed, at least in part, of a printed circuit board assembly (PCBA); a first impeller for motivating air positioned in said first sub-chamber; a second impeller for motivating air positioned in said second sub-chamber; a motor for rotating said first and second impellers, said motor having: a rotor and a stator mounted along said internal radial plane of, and substantially within, said motor support sleeve, such that an inner circumference of said stator is arranged concentrically radially about an outer circumference of said rotor, wherein the inner circumference of said stator is slightly larger than said outer circumference of said rotor, said PCBA including one or more components that control the motor; and a shaft, said shaft secured to said rotor via a first fastening device proximate to a first end of said shaft, said shaft secured to said second impeller via a second fastening device proximate to a second end of said shaft, wherein said first impeller is secured to at least part of said rotor via at least one of: a third fastening device or a structural integration.
2. The apparatus as recited in claim 1, wherein the motor is an electronically commutated direct current electric machine.
3. The apparatus as recited in claim 1, wherein a portion of said PCBA extends beyond an exterior of said housing.
4. The apparatus as recited in claim 1, further including multiple centrifugal blower apparatus interconnected together with said motor support, said motor support being common to all said multiple centrifugal blower apparatus.
5. The apparatus as recited in claim 4, wherein said apparatus includes multiple motors, each of said multiple motors being respectively associated with each of said multiple centrifugal blower apparatus.
6. The apparatus as recited in claim 5, wherein said one or more components of said PCBA includes one or more components that control all of said multiple motors.
7. The apparatus as recited in claim 5, wherein all of said multiple motors are electronically commutated direct current electric machines.
8. The apparatus as recited in claim 4, wherein each of said multiple centrifugal blower apparatus includes a respective shaft hub attached to said motor support, each said shaft hub having bearings to rotationally support each said shaft.
9. The apparatus as recited in claim 1, wherein said motor support is constructed of a material consisting of least one of: fiberglass, or metal.
10. The apparatus as recited in claim 1, wherein the one or more components of the PCBA comprise at least one of a group consisting of: a microprocessor, a transistor, a resistor, a diode, an electrical power connector, or a capacitor.
11. The apparatus as recited in claim 1, wherein said motor support sleeve includes a shaft hub having bearings to rotationally support said shaft.
12. The apparatus as recited in claim 1, wherein said stator is at least one from a group consisting of: glued, pressed, fastened, swaged, or staked to said motor support sleeve.
13. The apparatus as recited in claim 1, wherein said motor support sleeve comprises multiple stator pockets.
14. The apparatus as recited in claim 13, wherein said multiple stator pockets are arranged annularly and substantially within said motor support sleeve.
15. The apparatus as recited in claim 14, wherein said stator is aligned and engaged within said multiple stator pockets.
16. The apparatus as recited in claim 1, wherein said rotor is fixed to said shaft such that said rotor is aligned with said stator.
17. The apparatus as recited in claim 1, wherein said first fastening device is a hub collar.
18. The apparatus as recited in claim 1, wherein said second fastening device is a ring clamp.
19. The apparatus as recited in claim 1, wherein said third fastening device is a coupling bracket, and the at least part of said rotor is a rotor core, said coupling bracket being secured to said rotor core via at least one of: an adhesive or a weld.
20. The apparatus as recited in claim 1, wherein said first impeller, said second impeller, and said shaft rotate in unison with said rotor.
Description
DESCRIPTION OF THE DRAWINGS
(1) In the various figures, which are not necessarily drawn to scale, like numerals throughout the figures identify substantially similar components.
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DETAILED DESCRIPTION
(30) The following description provides detail of various embodiments of the invention, one or more examples of which are set forth below. Each of these embodiments are provided by way of explanation of the invention, and not intended to be an undue limitation of the invention. Further, those skilled in the art will appreciate that various modifications and variations may be made in the present invention without departing from the scope or spirit of the invention. By way of example, those skilled in the art will recognize that features illustrated or described as part of one embodiment, may be used in another embodiment to yield a still further embodiment. Thus, it is intended that the present invention also cover such modifications and variations that come within the scope of the appended claims and their equivalents.
(31) With reference now to the drawings, and first to
(32) Blower apparatus 10 may preferably be a centrifugal blower in which air flowing into first and second inlets 18, 20 substantially parallel to a blower inlet axis 26 may be re-directed radially of blower axis 26 by an impeller 28 rotating about blower axis 26. In a particular embodiment, blower apparatus 10 may be a double-inlet centrifugal blower employing first and second inlets 18, 20 at opposed first and second sides 14, 16. Moreover, blower apparatus 10 may be a double width, double inlet (DWDI) blower of the type illustrated. As indicated above, certain applications favor the utilization of a centrifugal blower, and may, in some cases, preferably employ a double inlet centrifugal blower.
(33) The illustrated embodiment of housing 12 employs first and second housing sections 8A, 8B which are secured together at a coupling location 30, as will be described in greater detail herein below. The coupling of first and second housing sections 8A and 8B establishes blowing chamber 22 and a defined air outlet 24. It is to be understood, however, that housing 12 may be fabricated in one or more sections/pieces, and may be assembled in a manner suitable for the desired application. In the illustrated embodiment, first and second housing sections 8A, 8B are substantially mirror images securable at coupling location 30, which may be substantially mid-way between first and second sides 14, 16. Coupling location 30 may therefore be disposed at a midportion 33 of housing 12. It is to be understood that housing 12 may be fabricated from a variety of materials encompassing numerous physical properties. Housing 12 may therefore be fabricated from metals, plastics, composites, ceramics, and the like.
(34) An operating system or subassembly 32 includes the rotating and stationary components of the air moving equipment of blower apparatus 10 in a manner that is substantially less aerodynamically intrusive than conventional approaches. Moreover, operating system 32 facilitates precise and stable support of moving components relative to stationary components, thereby allowing close operating clearances and higher motor efficiencies to compliment the aerodynamic efficiency described above.
(35) Operating system 32 includes a frame 34 that is arranged in blower chamber 22 between first and second sides 14, 16. Frame 34 may be a unitary cast member or an assembly which provides the structural support of blower apparatus 10. Consequently, frame 34 is preferably sufficiently strong to stably support the remaining components of blower apparatus 10 in precise and stable relative operating positions. A consequence of such stability is the opportunity for a fabricator to minimize the separation distance or clearance between components to further enhance the operating efficiencies of blower apparatus 10. Frame 34 may therefore be fabricated from a strong and relatively rigid material such as appropriate metals, plastics, composites, and ceramics. In one embodiment, frame 34 is a unitary cast body that is cast as a single piece from aluminum, or may be an injection molded engineered plastic.
(36) In the embodiment illustrated in
(37) Frame 34 may include a stator support portion 46 that extends radially outwardly from central portion 48 of frame 34. In some embodiments, central portion 48 is coextensive with a midplane 50 that extends substantially perpendicularly to blower axis 26 through midportion 33 of housing 12. Stator support portion 46 of frame 34 may include an upright portion 52 axially offset from central portion 48 to form a mounting pocket between central portion 48, upright portion 52, and upper brace portion 56 of frame 34. Upper brace portion 56 may extend from upright portion 52 in a direction substantially parallel to blower axis 26, and may further include a strengthening rib 58 for strengthening and inhibiting deflection of upper brace portion 56 in the operation of blower apparatus 10. The extent of axial displacement of upright portion 52 from central portion 48 of frame 34 may preferably be sufficient to define a mounting pocket of adequate axial width to facilitate mounting of rotor and stator elements substantially along midplane 50. It is contemplated, however, that frame 34 may be provided in a configuration without a mounting pocket, with the illustrated embodiment defining merely an exemplary embodiment of the present invention.
(38) Upright portion 52 of frame 34 may be substantially disk-shaped, or may instead be defined by a plurality of circumaxially spaced-apart upright members extending radially between central portion 48 and upper brace portion 56 of frame 34, and arranged annularly about blower axis 26. Upright portion 52 created through a plurality of upright members 52a may be an advantageous design for cost savings, weight savings, and aerodynamic benefits. The weight savings is of particular significance when frame 34 is constructed from a cast aluminum, however, it has been found that filling the openings, created by radially extending upright members 52a, with a lightweight potting increases efficiency of adjacent coils 93. Further, when upright portion 52 is constructed to form a solid or continuous backing, the wall may include a plurality of radially spaced reliefs or recesses 140 that extend or core into the region of the central portion 48 to reduce the weight and materials of the frame 34 (see, for example,
(39) An embodiment illustrated in
(40) Frame 34 further includes a housing mount portion 60 extending radially outwardly from upper brace portion 56 with a configuration suitable for securement of housing 12 thereto. In an embodiment of the invention, housing mount portion 60 may include an outer tab 62 and an inner surface 64 between which is defined a groove 66 that is sized and configured to receive housing 12. Inner surface 64 may comprise a surface of upper brace portion 56, or a surface of an inner tab 68 of housing mount portion 60. As best illustrated in
(41) Frame 34 may also include a support portion 70 extending between upper brace portion 56 and housing mount portion 60. Support portion 70 may be a solid or continuous body (as illustrated in
(42) Housing mount portion 60 defines coupling location 30 at which housing 12 is secured to operating system 32. Preferably, operating system 32 is coupled with housing 12 only at coupling location 30. As described in greater detail below, coupling location 30 is preferably disposed in a blower outlet portion 29 of housing 12 to minimize the aerodynamic impact of frame 34 in the operation of blower apparatus 10. In an illustrated embodiment, first and second housing sections 8A, 8B nest in respective grooves 66 of housing mount portion 60. In some embodiments, first and second housing sections 8A, 8B may be further secured to frame 34 at a locking cleat 72 of frame 34, wherein locking tabs 74A, 74B snap together to engage with locking cleat 72. Locking tabs 74A, 74B resiliently engage under an upper bar 73 of locking cleat 72, with a protrusion portion 75A, 75B of locking tabs 74A, 74B being urged through the resilience of locking tabs 74A, 74B into engagement with retention surfaces 75, 76 of locking cleat 72. In other embodiments, however, first and second housing sections 8A, 8B may be fastened, bolted, welded, soldered, or otherwise secured to one another and/or frame 34, as desired per application.
(43) Operating system 32 further includes a motor 80 that includes hub 44, a rotor 82 that is rotatably driven about blower axis 26, and a stator 84. Rotor 82 may include a rotor core or back iron 86 with a rotor element 88 annularly arranged about hub 44. Rotor 82 may further include a first impeller portion 90 including impeller blades 92 for motivating air out from blower chamber 22 through air outlet 24. As illustrated, stator 84 may be annularly arranged radially outwardly about rotor element 88, which may compromise a magnet secured to rotor core 86.
(44) In some embodiments, impeller blades 92 of impeller portion 90 extend in a substantially axial direction from rotor core 86, such that rotor core 86 forms a first impeller hub 87 to drive circumaxial motion of impeller blades 92 about blower axis 26, defined by rotor core 86 rotating with shaft 42 about blower axis 26. In such an embodiment, impeller portion 90 may be integrally formed with rotor 82, or may be secured directly thereto with fasteners, adhesives, weldments, or the like.
(45) Impeller portion 90 may instead constitute a distinct first impeller 91 coupled to rotor 82 for rotation about blower axis 26. First impeller 91 may be secured to rotor 82 so as to rotate in unison with rotor 82 and shaft 42 about blower axis 26. First impeller 91 may comprise a first wheel 94 having an inner flange 96, an outer flange 98, and impeller blades 92 secured there between. In addition, first impeller 91 may include a coupling bracket 102 for securing first impeller 91 to rotor core 86 of rotor 82. Coupling bracket 102 may be secured to rotor core 86 through fasteners, adhesives, welds, or the like. First impeller 91 has a first diameter D1 that may be somewhat greater than first air inlet diameter D2 but may be substantially equal to a rotor diameter D3. It is contemplated by the present invention that rotor diameter D3 may be somewhat greater or lesser than first diameter D1 of first impeller 91. However, such variances are considered to be within the scope of the term substantially equal, as used herein. In particular, the term substantially equal, as used herein, isintended to mean within +/15% difference between the two dimensions or properties being compared.
(46) In the illustrated embodiment, motor 80 includes a second impeller 106 having a second wheel 108 having an inner flange 110, and outer flange 112, and second impeller blades 114 secured along a substantially axial direction between inner and outer flanges 110, 112. Second impeller 106 is preferably arranged for motivating air out from blower chamber 22 through air outlet 24, and may be secured to shaft 42 to be rotatably driven about blower axis 26 by the circumaxial rotation of rotor 82. Second impeller 106 may be secured to shaft 42 in a manner which provides rotation of second impeller 106 in unison with first impeller 91. Typically, such an arrangement is facilitated through respective couplings of first impeller 91 and second impeller 106 to shaft 42 to rotate in unison with shaft 42 about blower axis 26. Second impeller 106 may be secured to shaft 42 with a ring clamp 116 or other suitable fastening mechanism. As described above, first impeller 91 may be coupled to shaft 42 through its connection or integration with rotor 82. In the illustrated embodiment, rotor 82 is coupled to shaft 42 at a hub collar 120, which is itself fixedly secured to shaft 42.
(47) One or more of first and second impellers 91, 106 may include forward-curved impeller blades 92, 114. The term forward-curved is understood in the art as an orientation of impeller blades 92, 114 that is distinguished from radial or backward-curved orientations. It has been found by the applicants that, at least in some embodiments, forward-curved impeller blades may provide aerodynamic advantages to the operation of blower apparatus 10.
(48) First and second air inlets 18, 20 may be substantially axially aligned along blower axis 26, in that blower axis 26 extends through a radial centerpoint of substantially circular first and second air inlets 18, 20.
(49) Motor 80 may be a brushless, direct-current electromagnetic motor in which rotor 82 is electromagnetically driven circumaxially about blower axis 26 by a stationary stator 84, as is understood in the art. In the present arrangement, however, stator 84 may be closely radially outwardly positioned with respect to rotor 82, and precisely secured to frame 34 in order to minimize necessary clearances as between the stationary stator 84 and the rotating rotor 82. Stator 84 may be pressed, glued, fastened, swaged, staked, and the like to stator support portion 46 of frame 34 annularly about magnetic rotor element 88 of rotor 82. Magnetic rotor element 88 may be bonded or fastened to rotor core 86 in a position that is substantially radially and annularly aligned with stator 84, such that stator 84 and rotor element 88 are annular rings annularly aligned with midplane 50. It is contemplated, however, that rotor element 88 and stator 84 may be somewhat axially displaced from one another, so as to not be precisely annularly aligned about hub 44. The arrangement of stator 84 and rotor element 88, however, is preferably suitable for efficiently driving the rotation of rotor 82.
(50) Stator 84 includes a welded lamination stack 85 with molded insulators 89 and electrically conductive coils 93. Insulators 89 are secured between lamination stack 85 and coils 93, as is known in the art. Stator 84 is therefore compactly arranged circumaxially about blower axis 26 and in close radial outward proximity to magnetic rotor element 88.
(51) In some embodiments, for example, an inner diameter D4 of stator 84 may be substantially equal to first diameter D1 of first impeller 91. Thus, each of first diameter D1, an outer diameter of rotor element 88, and an inner diameter of stator 84 may be substantially equal to one another. Such an arrangement provides for a relatively compact motor 80 with minimized clearances and resultant high efficiencies. Moreover, motor 80 may be completely contained within the standard scroll-shaped housing 12, and yet provide enhanced motor output as a consequence of a relatively long leverage arm afforded by an enlarged diameter D1, D3, D4 as compared to conventional motors located in the blower hub area. A particular arrangement provides for stator 84 concentrically arranged about rotor element 88.
(52) An aspect of the present invention which enhances aerodynamic efficiency over conventional approaches is in locating the stator and the connection between the operating system and the housing downstream from the impeller. For the purposes hereof, the term downstream is intended to refer to the airflow progress through blower apparatus 10. In this regard, first and second air inlets 18, 20 are upstream from first and second impellers 91, 106, respectively. Airflow enters a respective first or second air inlet 18, 20 to encounter a respective first or second impeller 91, 106, so as to be directed into an outlet plenum 31 of housing 12, and ultimately out through air outlet 24. Consequently, those structures or components identified as being downstream of another structure or component is located in blower apparatus 10 in a position which is exposed to the cooling air subsequent to the comparison structure or component during the normal operation of blower apparatus 10. In this case, therefore, coupling location 30 is disposed at the portion of housing 12 defining outlet plenum 31, fluidly downstream from impellers 91, 106. In this manner, motor 80 of the present invention uses space within housing 12 that is far less sensitive to aerodynamic performance than configurations of the prior art. By limiting aerodynamic incursion, the arrangement of the present invention yields higher efficiencies and lower noise levels.
(53) Electrical wiring 125 may be conveniently located at blower housing, and need not extend through a hollow support shaft within the aerodynamic inlet portion. The leads of wiring 125 may therefore extend through an access 127 of housing 12, directly to motor 80.
(54) An embodiment illustrated in
(55) Motor 132 rotates impellers 128 and 130 and is preferably an electronically commutated type which is also known as a brushless DC motor. A brushless motor typically includes a printed circuit board assembly (PCBA) having motor driver components that controls the rotation of the motor. The driver components include, for example, a microprocessor, transistors, resistors, diodes and capacitors. The PCBA is preferably either a composite fiberglass (typically FR-4) or a metal substrate.
(56) The motor support 134 is preferably constructed of the required PCBA of motor 132. Utilizing the PCBA as the motor support 134 reduces the size of the centrifugal blower 100 by eliminating the need for a remotely mounted PCBA. The PCBA motor support 134 also simplifies the construction of the blower, improves efficiency and lowers manufacturing costs. Further, the PCBA motor support 134 lowers power losses in wiring, eliminates connectors that may have failures and a metal substrate PCBA transfers heat away from the motor 132 thus increasing bearing life.
(57) Motor support 134 includes a central aperture 136 extending there through. Motor 132 includes a motor support frame or motor support sleeve or adapter 146 that mounts and firmly engages the motor 132 to the motor support 134 in the central opening or aperture 136. Motor 132 generally includes rotor 182 and stator 184. A hub 144 is attached or is formed integral with the adapter 146. Bearings 140 are contained within hub 144 and are adapted to receive motor shaft or spindle 142. The spindle 142 extends through hub 144 and impellers 128 and 130 are mounted on opposing end portions of the spindle 142. The bearings 140 allow the spindle and impellers to freely rotate within the corresponding sub-chambers 110 and 112. Rotor 182 is also affixed to the spindle 142 along a mid-portion of the spindle such that the rotor is aligned with the stator 184. The outer circumference of rotor 154 is slightly less that the inner circumference of the stator portion adjacent the rotor 182.
(58) Stator 184 may be aligned and engaged within stator pockets formed in the motor support sleeve or adapter 146. The stator windings 148 wind about cores or insulators and are annularly arranged in stator pockets radially outwardly about rotor element 182. Rotor 182 is electromagnetically driven circumaxially (which rotates the spindle and connected impellers) by the stationary stator 184 as is understood in the art. In the present arrangement, however, stator 184 may be closely radially outwardly positioned with respect to rotor 182, and precisely secured to adapter 146 in order to minimize necessary clearances between the stationary stator 184 and the rotating rotor 182. Those skilled in the art will appreciate that the motor support 134 may be modified to include the adapter 146 as an integral component of the motor support 134. Stator 184 may be pressed, glued, fastened, swaged, staked, and the like to the adapter 146.
(59) An embodiment of the motor is shown in greater detail in
(60) Stator 382 is aligned and engaged within stator pockets 350 formed in the motor support sleeve or adapter 346. The stator windings 348 wind about cores or insulators 356 and are annularly arranged in the stator pockets 350 radially outwardly about rotor element 380. The core end 358 of the stator core 356 is arranged closely radially outward with respect to a magnetic rotor element 388 of the rotor 380, in order to minimize necessary clearances between the stationary stator 382 and the rotating rotor 380.
(61) An embodiment illustrated in
(62) Motor 232 rotates impellers 228 and 230 and is mounted to the motor support PCB 234 in a central aperture 236 extending through the motor support 234. Motor 232 includes the motor support adapter 246 that mounts and firmly engages the motor 232 to the motor support 234 in the central opening or aperture 236. Motor 232 generally includes rotor 280 and a stator. A hub 244 is attached or is formed integral with the adapter 246. Bearings (not shown in
(63) The embodiment of the invention illustrated in
(64) These and various other aspects and features of the invention are described with the intent to be illustrative, and not restrictive. This invention has been described herein with detail in order to comply with the patent statutes and to provide those skilled in the art with information needed to apply the novel principles and to construct and use such specialized components as are required. It is to be understood, however, that the invention can be carried out by specifically different constructions, and that various modifications, both as to the construction and operating procedures, can be accomplished without departing from the scope of the invention. Further, in the appended claims, the transitional terms comprising and including are used in the open ended sense in that elements in addition to those enumerated may also be present. Other examples will be apparent to those of skill in the art upon reviewing this document.