Blower for breathing apparatus

Abstract

To provide a small blower.SOLUTION: There is provided a blower for a breathing device. The blower comprises: a bottom support body with a stub axle; an upper support body having a stub axle; a motor core including a motor stator and a rotor; and an impeller coupled to the motor core through a shaft. The shaft is rotatably coupled to the stub axle of the upper support body at a first end, and coupled through the stub axle of the bottom support body at a second end 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a reduced footprint blower, preferably for use in a respiratory apparatus such as a continuous positive airway pressure (CPAP) respiratory apparatus. [Background technology]

[0002] Blowers are also used in a variety of respiratory and other applications. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide a compact blower that can be used in a variety of applications where lower weight, low inertia and / or small size are desirable, such as portable, body / head mounted and / or miniaturized breathing apparatus. [Means for solving the problem]

[0004] In one aspect, the invention may include a blower for a respiratory apparatus including a bottom support having a stub axle, a top support having a stub axle, a motor core including a motor stator and a rotor, and an impeller coupled to the motor core via a shaft, the shaft rotatably coupled at a first end to the stub axle of the top support and at a second end via the stub axle of the bottom support.

[0005] Optionally, the shaft is rotatably coupled to the stub axle at the first end and the second end by bearings within the shaft.

[0006] Optionally, the stub axle is resilient and / or elastic.

[0007] Optionally, the shaft is partially or completely hollow, and the first and second ends have bearings within the hollow.

[0008] Optionally, each bearing includes an inner race and an outer race, and each stub axle is coupled to a respective inner bearing race.

[0009] Optionally, the maximum diametric dimension of the shaft is independent of the dimension of the bearing diameter.

[0010] Optionally, the blower is an axial inlet / axial outlet blower.

[0011] Optionally, the blower is a single stage axial inlet / axial outlet blower.

[0012] Optionally, the impeller is integrally formed with the shaft or is coupled by a press fit.

[0013] Optionally, the rotor or magnets are press-fit onto the shaft.

[0014] In another aspect, the invention may include a blower for a breathing apparatus including a housing, a motor core within the housing, an impeller coupled to a rotor via a shaft, and an airflow stator, the impeller rotating within an area within the housing and directing outlet air axially through the airflow stator.

[0015] Optionally, there are no swirls.

[0016] Optionally, the housing includes a lower housing having an area for the motor and one or more apertures for axially receiving inlet air.

[0017] Optionally, the blower is single stage.

[0018] Optionally, the ratio of impeller diameter to housing diameter is at least about 90%.

[0019] In another aspect, the present invention may include a blower for a respiratory apparatus including a housing, a motor core within the housing, and an impeller coupled to a rotor via a shaft, the impeller including a hub, blades extending from the hub, and stub blades supported between the blades.

[0020] Optionally, an annular ring extends around the blade and supports the stub blade.

[0021] Optionally, the annular ring has an edge oriented towards the outlet to guide the outlet air axially.

[0022] Optionally, the blower comprises: - Diameter of about 53mm or less, Approximately 21 mm or less in height, and / or Weight of about 50 grams or less, or preferably 47 grams or less, and preferably 27 grams or less has.

[0023] Optionally, the impeller comprises: -Thickness of about 3mm or less A diameter of about 48 mm or less, or more preferably 48.4 mm; -Weight less than 3 grams has.

[0024] Optionally, the impeller is integrally formed with the shaft or is coupled by a press fit.

[0025] Further aspects of the invention, which should be considered in all its novel aspects, are set forth in the following description.

[0026] It should be noted that various changes and modifications to the preferred embodiment described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the scope and spirit of the presently disclosed device and system and without diminishing its attendant advantages. For example, various components can be repositioned as needed. Accordingly, such changes and modifications are intended to be included within the scope of the presently disclosed device and system. Moreover, not all of the features, aspects, and advantages are necessary to implement the presently disclosed device and system. Accordingly, the scope of the presently disclosed device and system is defined solely by the following claims.

[0027] The reference to any prior art in this specification is not, and should not be construed as, any form of acknowledgment or suggestion that this prior art forms part of the common general knowledge in the field of endeavor in any country in the world. In the foregoing description, reference has been made to components having integers or their known equivalents, and these integers are incorporated herein as if individually set forth.

[0028] Unless otherwise clearly required, throughout the specification and claims, the words "comprise", "comprising", and the like are to be interpreted in an inclusive sense, i.e., "including but not limited to," rather than an exclusive or exhaustive sense.

[0029] The devices and systems of the present disclosure may also be broadly said to include any or all of the components, elements, and features referred to or shown in the specification of this application, individually or collectively, in any combination of two or more of such components, elements, or features.

[0030] Embodiments of the low profile blower will now be described with reference to the following drawings: [Brief description of the drawings]

[0031] [Figure 1]FIG. 1 illustrates a cutaway perspective view of a low profile blower having an axial input and an axial output according to a first embodiment. [Diagram 2] 1 shows a partial exploded view of a low profile blower. [Diagram 3] FIG. 13 shows a cross-sectional perspective view of a low profile blower having two axial inlets and an axial output according to a second embodiment. [Figure 4] 13 shows a cross-sectional perspective view of a low profile blower having an axial inlet and an axial output according to a third embodiment. [Diagram 5] 13 illustrates another embodiment of an impeller that may be used with any of the previous embodiments. [Figure 6] 13 illustrates another embodiment of an impeller that may be used with any of the previous embodiments. [Figure 7] 2 shows two alternative stub axle and bearing arrangements. [Figure 8] 13 shows a cross-sectional view of a low profile blower having an axial inlet and a radial outlet according to a fourth embodiment. [Figure 9] FIG. 13 illustrates a perspective view of a low profile blower having an axial inlet and a radial outlet according to a fourth embodiment. [Figure 10] FIG. 13 illustrates a perspective view of a low profile blower having an axial inlet and a radial outlet according to a fourth embodiment. [Figure 11] FIG. 13 illustrates a perspective view of a low profile blower having an axial inlet and a radial outlet according to a fourth embodiment. [Figure 12A] 13 illustrates various configurations of stub axles, bearings, and shafts that may be used in the variants. [Figure 12B] 13 illustrates various configurations of stub axles, bearings, and shafts that may be used in the variants. [Figure 12C] 13 illustrates various configurations of stub axles, bearings, and shafts that may be used in the variants. [Figure 13A] 13A-13C show various inlet / outlet configurations of the blower that may be used in the variant. [Figure 13B]13A-13C show various inlet / outlet configurations of the blower that may be used in the variant. [Figure 13C] 13A-13C show various inlet / outlet configurations of the blower that may be used in the variant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] First embodiment 1 and 2 show one embodiment of a single stage axial inlet / axial outlet blower (also called a flow generator or fan). The low profile blower is for use as a flow generator, for example, in a CPAP device, a high flow therapy device, or any other respiratory device. Alternatively, the low profile blower may be used in any other suitable application.

[0033] Blower 10 includes a bottom housing portion ("lower housing") 11. The lower housing is formed as an annular wall 12 with an internal annular shelf 13. Radial ribs 14 extend from below the annular shelf (or pan). The ribs are formed as wall portions 14a with radial arms 14b extending from the lower portion and meeting at a central (lower) hub 15. This forms a recessed area ("sub-housing") 20 (see FIG. 2) between ribs 14 and ribs 13, the annular shelf, and the lower hub 15 for receiving motor core 4 including motor stator 16 and rotor 17. The lower housing 11 / lower hub 15 functions as at least a partial support for a bearing which provides bottom / lower support for motor stator 16 and further support for rotor 17 and impeller 18 assembly. Apertures or gaps between ribs 14 provide an axial inlet for airflow "A", which also provides cooling for the motor.

[0034] Blower 10 also includes an upper housing portion ("upper housing") 19 that rests on lower housing 11. The upper housing includes a top plate 21 (inner lid) with a central boss forming an upper hub 22. An air flow ring 23 surrounds the top plate. The air flow ring includes an annular perimeter (outer annular wall) 24 with a rebate 24a (see FIG. 2) that rests on top of and joins to annular wall 12 of lower housing 11, and an inner annular wall 25. This may be by bayonet pins, bumps, snap-fit, adhesive, ultrasonic or friction welding, or any other suitable means. Between the inner and outer annular walls is formed a channel 26 (see FIG. 2), e.g. curved, for receiving, slowing down, and generating pressure on airflow from impeller 18. The upper housing serves as a top / upper support for the rotor and impeller assembly via bearings 28.

[0035] Although terms such as "top", "bottom", "upper", "bottom" and the like are used throughout this specification, it will be understood that these terms are relative terms used merely for reference in the drawings. The actual blower in use may be oriented differently, and references to a vertical position herein should not be considered limiting and should not be considered to imply or limit the actual orientation of the blower and its components.

[0036] The motor core 4 includes a motor stator 16 and a rotor 17. The motor stator is supported on the radial arms 14b of the ribs 14 in the sub-housing 20. The motor stator may be friction-fitted, overmolded, or glued to the sub-housing 20, for example. The motor stator 16 includes an annular stacked lamination core 16a with a toroidal winding 16b. The rotor includes a toroidal magnet 17a coupled to a shaft 27. The magnet may be coupled to the shaft by friction-fitting, or may be coupled by overmolding or gluing. The lower end of the shaft 27 has an annular rebate 27a (see FIG. 2) having an outer diameter corresponding to the inner diameter of the annular magnet 17a for receiving the annular magnet. The shaft 27 is a cylindrical tube in the form of a bearing tube. For example, a bearing 28 is disposed in the bearing tube at each end. The bearing may be friction-fitted to the shaft 27, or may be coupled by overmolding or gluing. Although the reference numbers refer to the top bearing 28, they are equally applicable to the bottom bearing. Each bearing race includes an outer annular bearing race / housing 28a, an inner annular bearing race / housing 28b, and a ball or roller bearing 28c that can move in a cage between them. As one non-limiting example, the bearings may have an outer diameter of about 4mm to 8mm, an inner diameter of about 1.5mm to 3mm, and a thickness of about 2mm to 4mm. The outer bearing race 28a rotates relative to the inner bearing race 28b. The inner bearing race may remain stationary. In an alternative form, a plain bearing or bushing may be used instead. The shaft 27 is conveniently supported between the upper housing 19 and the lower housing 11. Both the upper and lower housings include stub axles 29a, 29b in the form of resilient and / or elastic projections that extend into and are coupled to the bearing races 28a, 28b of each bearing at each end of the shaft. Preferably, the stub axles may be solid and / or rigid and are overmolded with a resilient and / or flexible material such as silicone, or alternatively, the stub axles are formed from an elastomer (e.g., silicone) or other resilient and / or elastic material and friction fit within the respective bearing races.Alternatively, the stub axle may be solid.

[0037] Each of the stub axles extends from a respective upper and lower housing to a distal end. The stub axles extend toward each other. Each of the stub axles is substantially cylindrical in shape. In other embodiments, one or both of the stub axles are reduced or decreased in diameter as they extend away from their respective upper and lower housings. The distal end of each stub axle is rounded. However, in other embodiments, the distal end of one or both of the stub axles is substantially flat. Each stub axle also includes a shoulder formed by a flange or step. In other embodiments, the shoulder is formed by a taper of the stub axle. The shoulder is located from or near the proximal end of each stub axle to the respective housing from which each stub axle extends. The upper and lower bearings engage the shoulder or each stub axle to limit axial movement of the bearing arrangement away from the shaft. The shaft also has a shoulder formed at each end in opposing relationship to each respective stub axle shoulder. Each shaft shoulder is formed as a recess or step in the interior surface of the shaft. In other embodiments, the shaft shoulder is formed by a taper in the interior surface of the shaft. Upper and lower bearings also engage each shaft shoulder such that they are captured between the shaft shoulder and the stub axle shoulder. The shaft / stub axle / bearing arrangement allows the shaft to be rotatably supported / coupled to the upper / lower housings in a simply supported manner.

[0038] For example, the outer diameter of the outer bearing race 28a may be about 4 mm. The hollow shaft may have a corresponding diameter of about 4 mm to allow for a snug fit of the bearing race 28a. The outer shaft dimension at the rebate 27a may be about 5 mm.

[0039] The impeller 18 may be bonded (e.g., press-fit) onto the shaft 27 or may be integrally formed with the shaft 27 or may be integrally formed, overmolded, or glued onto the shaft. The impeller is shown in FIG. 2. The shaft may be of similar diameter as the shaft in the conventional topology, allowing for a tight mechanical coupling of the impeller and magnet. Since the bearing is mounted inside the shaft, the diameter of the shaft is not affected by the inner diameter of the bearing. The outer diameter of the shaft may therefore be of any suitable size to allow for a tight coupling of the impeller, for example about 5 mm, or alternatively about 3 mm to about 5 mm. Since the bearing is inside the shaft and the size of the bearing (e.g., diameter size) can be selected based on the acceptable bearing speed, a large diameter shaft can still be used without being affected by the size of the bearing diameter. For example, a smaller bearing allowing for a higher revolutions per minute (RPM) may be used because the balls do not move as quickly in the races due to the smaller diameter. Smaller bearings are generally rated for higher RPM, so using smaller bearings allows for higher RPM. The impeller is shown in FIG. 2. It is also shown in more detail in FIG. 5 and FIG. 6. Similarly, the magnet / rotor 17a / 17 is pressed against the shaft. The same advantage applies here that the shaft may be appropriately sized to allow a firm connection. The impeller 18 includes a hub portion 5 and flat forward-swept (full-length) blades (sometimes called "vanes") 6 extending radially from and connecting to the hub portion. (Alternatively, the blades may be swept-back or radial). Each blade includes a vertical flat portion extending from the hub. An annular rib / ring 7 is formed in the blades 6 and extends between the blades 6 to provide stiffness around the blades. The ring curves towards the outlet 7a to provide stiffness to the blades and also to guide the airflow into the airflow stator, as will be described below. A number of short stub (partial-length) blades 8 (also called "splitter blades") extending partway down the hub are spaced between the full-length blades 6. In the illustrated embodiment, each of the stub blades is also swept forward.Annular ribs 7 are formed in and extend between the stub blades 8, thus supporting the stub blades 8. The stub blades provide the additional pressure normally obtained with additional blades without the need for material extending to the hub, which reduces the air gap at the hub. Reducing the air gap at the hub reduces the maximum flow performance of the blower 10. If there are too many blades (and therefore too little air gap at the hub due to too many blades), the inlet flow will be choked, restricting the outlet air flow of the blower.

[0040] In the impeller as shown in Figures 5 and 6, there are three stub blades between each pair of full-length blades 6. However, it will be understood that other numbers of sub-blades 8 are also possible. For example, there may be 1 to 7 stub blades, or 3 to 5 stub blades, or 1, 2, 3, 4 or 5 stub blades. In the illustrated embodiment of Figures 3 and 5, the stub blades 8 may be of different lengths. The central or intermediate stub blade of each group of stub blades between adjacent full-length blades is longer than the adjacent stub blades (i.e. the stub blades on either side of the central stub blade of that group). The side stub blades are of approximately the same length. Despite the different lengths, the peripheral ends of all the stub blades of each group are located at the same radial distance around the impeller. This means that the inner end of the longer central stub blade is located radially closer to the center of the impeller than the inner ends of each side stub blade. The peripheral edges of all of the stub blades and full length blades are also spaced the same radial distance around the impeller. Each of the stub blades tapers toward its inner end; that is, each stub blade decreases in height toward its inner end. To achieve this taper, each stub blade has a convex upper edge. Thus, each stub blade is narrower at its inner end relative to its peripheral edges.

[0041] Material properties and construction techniques suggest that increasing the number of blades is advantageous when pumping liquids due to the high density of the liquid. For example, multiply the rotational speed (Hz) by the number of blades to get the blade passing frequency. Human hearing is sensitive to tone inputs between 300 Hz and 15 kHz, so it is classified as noise if it is not musical. High frequency sound waves are easier to attenuate compared to low frequency noise. A typical CPAP (Continuous Positive Airway Pressure) blower has a rotational speed of about 180 revolutions per second. Therefore, it is advantageous to increase the number of blades to improve the attenuation characteristics. Different unequal prime numbers such as 7, 11, 13, 17, 19 and 23 promote a reduction in the general part interaction between the rotor and the motor stator. As another example, the deceleration of the fluid by abruptly increasing the flow area can lead to boundary layer separation, flow reversal, and turbulent losses. For pressure loss recovery by diffusion mechanisms, the angle between the blades should not exceed 12 degrees. Dividing the total circumference (360 degrees) by the sum of the blade thickness angle and the flow passage angle gives the minimum number of blades for optimal diffusion. Adding more blades than is optimal reduces the flow passage size and increases pressure loss.

[0042] However, increasing the number of blades to distribute the forces that a single blade must support and to aid in noise elimination reduces the size of the flow passage in the impeller, which is detrimental. We overcome this problem by using stub / splitter blades. To minimize blockage in the vicinity of the hub, some blades can be truncated, called splitter blades. Splitter blades can be placed on a support disk or shroud to transfer some of their load to the hub. However, blisks (bladed disks) and shrouded impellers have a fairly high rotational moment. We avoid this by supporting the splitter blades on ribs 7 as described. This reduces the inertia on the shroud or disk and also minimizes blockage.

[0043] The motor is controlled using a power supply and a controller to rotate the impeller to generate the desired output airflow (both pressure and / or flow rate). Air is drawn into an axial inlet aperture by the impeller, passes over the motor to provide cooling, and is guided by the impeller blades to the airflow stator and ring. The airflow stator ring slows the flow to create pressure, and the flow is guided axially exiting the airflow stator ring.

[0044] Second embodiment Figure 3 shows another embodiment of a single stage axial inlet / axial outlet blower. This embodiment has two axial inlets, one at the top and one at the bottom of the motor. Two inlets allows for a smaller inlet, which also allows for a larger effective blade length. There is also less noise associated with a smaller inlet.

[0045] The blower 50 includes an upper housing portion ("upper housing") 51 including a plate 51a having an annular edge 51b. At the center of the plate, a plurality of radial ribs 52 extend to a central (upper) hub 54 formed as a boss. The ribs create an aperture 53 in the plate forming one axial air inlet to the blower 50. In use, airflow "B" enters the inlet. The blower also includes a bottom housing portion ("lower housing") 55. The lower housing is formed from an outer annular wall 56 having a concentric inner annular stub wall 57a from which an annular shelf 57b extends radially. A curved channel 57c is formed between the outer and inner annular walls creating an annular airflow stator ring 57 for receiving, slowing down and generating pressure on the airflow from the impeller 27. Ribs 58 extend downward from the edge of the annular shelf 57b and then extend radially to meet at a central (lower) hub 59. This forms a recessed area between the ribs ("sub-housing"), an annular shelf, and a lower hub for receiving the motor core 4 including the motor (core) stator 16 and rotor 17. The lower housing / lower hub acts as a bottom / lower support for the motor stator 16 and at least partial support for the bearings, and also provides support for the rotor and impeller assembly. Apertures formed between the ribs provide another axial air inlet "A" to the blower. This also provides cooling for the motor. The two smaller axial inlets (top and bottom) provide a larger effective blade length. The upper housing is bonded to the top of the outer annular wall of the lower housing. This may be by bayonet pins, bumps, snap fits, adhesives, ultrasonic or friction welding, or any other suitable means.

[0046] The motor core includes a motor stator 16 and a rotor 17. The motor stator is supported on a lower hub 59 within a sub-housing. The motor stator includes a stacked laminated core with toroidal windings. The rotor includes an annular or toroidal magnet coupled to a shaft. The lower end of the shaft has an annular rebate with an outer diameter corresponding to the inner diameter of the annular magnet for receiving the annular magnet. The shaft is a cylindrical tube in the form of a bearing tube. The bearings are disposed within the bearing tubes at each end. Each bearing race includes an outer annular bearing race / housing and an inner annular bearing race / housing with ball bearings therebetween. As one non-limiting example, the bearings may have an outer diameter of about 4 mm to 8 mm, an inner diameter of about 1.5 mm to 3 mm, and a thickness of about 2 mm to 4 mm. The inner bearing race rotates relative to the outer bearing race. In an alternative form, plain bearings or bushings may be used instead. The shaft is conveniently supported between an upper housing and a lower housing. Both the upper and lower housings include stub axles in the form of resilient and / or elastic protrusions at each end of the shaft that extend into and couple to the bearing races of the respective bearings. Preferably, the stub axles are formed from an elastomer (e.g., silicone) or other resilient and / or elastic material and are in friction fit with the respective bearing races. Alternatively, the stub axles may be solid and / or rigid and are overmolded with a resilient and / or flexible material. Alternatively, the stub axles may be solid. The stub axles may have any one or more of the features described above with respect to the first embodiment.

[0047] The impeller may be coupled (e.g., press-fit) onto the shaft or may be integrally formed with the shaft. The shaft may be of similar diameter as the shaft in the conventional topology, allowing for a rigid mechanical coupling of the impeller. Since the bearing is mounted inside the shaft, the diameter of the shaft is not affected by the inner diameter of the bearing. The outer diameter of the shaft may therefore be of an appropriate size to allow for a rigid coupling of the impeller, for example about 5 mm, or alternatively about 3 mm to about 5 mm. Since the bearing is inside the shaft and the size (e.g., diameter) of the bearing may be selected based on the acceptable bearing speed, a large diameter shaft may still be used without the effect of the size of the bearing diameter (leading to unnecessarily high bearing speeds). The impeller is shown in FIG. 2. The impeller is also shown in more detail in FIG. 5 and FIG. 6. Similarly, the magnet / rotor 17a / 17 is pressed onto the shaft. The same advantage applies here that the shaft may be of an appropriate size to allow for a rigid coupling. The impeller includes a hub portion and flat forward-swept (full-length) blades that extend radially from and connect to the hub portion (alternatively, the blades can be swept-back or radial). Each blade includes a vertical flat portion that extends from the hub. An annular rib / ring 7 is formed within the blades 6 and extends between the blades 6 to provide stiffness around the blades. The ring curves toward the outlet 7a to provide stiffness to the blades and also guide the airflow into the airflow stator, as described below. A number of short stub (partial-length) blades 8 (also referred to as "splitter blades") that extend partway down the hub are spaced apart between the full-length blades 6. The annular ribs are also formed within and extend between the blades, thus providing support for the blades. The stub blades provide additional pressure without requiring material to extend to the hub, which reduces the air gap at the hub. Reducing the air gap at the hub reduces the maximum flow performance of the blower 10. If there are too many blades (and therefore too little air gap in the hub due to too many blades), the inlet flow will be blocked, restricting the outlet airflow of the blower.The impeller may be according to the embodiment shown in Figures 5 and 6 and may have any one or more of the features described above in relation to the first embodiment.

[0048] This embodiment has the same advantages as those described in the previous embodiment. This embodiment also has the added advantage of dual axial inlets, providing a less restrictive air inlet. This embodiment also provides motor cooling.

[0049] Third embodiment 4 shows yet another embodiment 60 of a single stage axial inlet / axial outlet blower. This embodiment is similar to the previous embodiment, but has one axial inlet at the top of the motor.

[0050] The motor includes an upper housing portion ("upper housing") 51 including a plate 51a having an annular edge 51b. At the center of the plate, a number of ribs 52 extend to a central upper hub 54 formed as a boss. The ribs create an aperture 53 in the plate 51a forming one axial air inlet to the blower 60. In use, airflow "B" enters the inlet. The blower also includes a bottom housing portion ("lower housing") 65. The lower housing is formed from an outer annular wall 66 having a concentric inner annular stub wall 67a from which an annular shelf 67b extends radially. A curved channel 67c is formed between the outer and inner annular walls creating an annular airflow stator ring 67 for receiving, slowing down and generating pressure on the airflow from the impeller 27. An annular wall 68a extends downwardly from the edge of the annular shelf, followed by a floor 68b extending radially to meet at a central lower hub 69. This forms a recessed area ("sub-housing") 68 between the wall and the annular shelf, and a lower hub for receiving the motor core including the motor stator and rotor. The lower housing / lower hub serves as bottom / lower support for the motor stator and at least partial support for the bearings, and also provides support for the rotor and impeller assembly. The upper housing is bonded to the top of the outer annular wall of the lower housing. This may be by bayonet pins, bumps, snap fits, adhesives, ultrasonic or friction welding, or any other suitable means.

[0051] The motor core includes a motor stator and a rotor. The motor stator is supported on the lower hub within a sub-housing. The motor stator includes an annular stack lamination core with toroidal windings. The rotor includes an annular or toroidal magnet coupled to a shaft. The lower end of the shaft has an annular rebate with an outer diameter corresponding to the inner diameter of the annular magnet for receiving the annular magnet. The shaft is a cylindrical tube in the form of a bearing tube. The bearings are disposed within the bearing tubes at each end. Each bearing race includes an outer annular bearing race / housing and an inner annular bearing race / housing with a bearing therebetween. As one non-limiting example, the bearings may have an outer diameter of about 4 mm to 8 mm, an inner diameter of about 1.5 mm to 3 mm, and a thickness of about 2 mm to 4 mm. The inner bearing race rotates relative to the outer bearing race. In an alternative form, plain bearings or bushings may be used instead. The shaft is conveniently supported between an upper housing and a lower housing. Both the upper and lower housings include stub axles in the form of resilient and / or elastic protrusions at each end of the shaft that extend into and couple to the bearing races of the respective bearings. Preferably, the stub axles are formed from an elastomer (e.g., silicone) or other resilient and / or elastic material and are in friction fit with the respective bearing races. Alternatively, the stub axles are solid and / or rigid and are overmolded with a resilient and / or flexible material. Alternatively, the stub axles may be solid. The stub axles may have any one or more of the features described above with respect to the first embodiment.

[0052] The impeller may be coupled onto the shaft or may be integrally formed with the shaft. The shaft may be of similar diameter as the shaft in the conventional topology, allowing a rigid mechanical coupling of the impeller. Since the bearing is mounted inside the shaft, the diameter of the shaft is not affected by the inner diameter of the bearing. The outer diameter of the shaft may therefore be of an appropriate size to allow a rigid coupling of the impeller, for example about 5 mm or alternatively about 3 mm to about 5 mm. Since the bearing is inside the shaft and the size (e.g. diameter size) of the bearing may be selected based on the acceptable bearing speed, a large diameter shaft may still be used without the effect of the size of the bearing diameter (leading to unnecessarily high bearing speeds). The impeller is shown in FIG. 2. The impeller is also shown in more detail in FIG. 5 and FIG. 6. Similarly, the magnet / rotor 17a / 17 is pressed into the shaft. The same advantage applies in this case that the shaft may be of an appropriate size to allow a rigid coupling. The impeller includes a hub portion and flat forward-swept (full-length) blades that extend radially from and connect to the hub portion (alternatively, the blades can be swept-back or radial). Each blade includes a vertical flat portion that extends from the hub. An annular rib / ring 7 is formed within the blades 6 and extends between the blades 6 to provide stiffness around the blades. The ring curves toward the outlet 7a to provide stiffness to the blades and also guide the airflow into the airflow stator, as described below. A number of short stub (partial-length) blades 8 (also referred to as "splitter blades") that extend partway down the hub are spaced apart between the full-length blades 6. Annual ribs are also formed within and extend between the blades, thus providing support for the blades. The stub blades provide additional pressure without requiring material to extend to the hub, which reduces the air gap at the hub. Reducing the air gap at the hub reduces the maximum flow performance of the blower 10. If there are too many blades (and therefore too little air gap in the hub due to too many blades), the inlet flow will be blocked, restricting the outlet airflow of the blower.The impeller may be according to the embodiment shown in Figures 5 and 6 and may have any one or more of the features described above in relation to the first embodiment.

[0053] This embodiment has the same advantages as those described in the previous embodiment.

[0054] Another advantage of the resilient stub axles described in the above embodiments is that they accommodate misalignment of the connection between the shaft and the bearings and allow the bearings to be preloaded.

[0055] In the above described embodiment, the shaft is hollow to allow bearings to sit within each end of the shaft. In other embodiments, the shaft may only be partially hollow, but with enough space for bearings to sit within the shaft. For example, the shaft may have recesses at each end for the bearings to sit within.

[0056] 7, in another alternative, the stub axles of the above embodiments may not extend all the way into the bearing. Rather, each stub axle may only extend partially into the bearing (see, e.g., stub axle 70) or only contact the bearing (see, e.g., stub axle 71). These arrangements still provide sufficient support and allow rotation.

[0057] Fourth embodiment 8-10 show yet another embodiment of a blower 80. This blower is a single stage axial inlet / radial outlet blower.

[0058] The blower 80 includes a bottom housing portion ("lower housing") 85. The lower housing is formed as a generally round body having a cylindrical side surface 85a, a toroidal base portion 85b that forms part of an annular collector 86 (for collecting flow from the impeller), and an inner motor region 87 (see FIG. 10) centrally and concentrically located within the annular collector. The inner motor region is formed as a recess within the lower housing. The collector inner wall 86a curves upwardly to form the inner motor region 87. The inner motor region ("sub-housing") 87 is for receiving a motor core 88 assembly including a motor (core) stator 89 and rotor 90. A central plate 91 having a central aperture is supported on the inner collector wall 86a. The plate is dimensioned to have an annular gap 92 between the plate perimeter 93 and the inner cylindrical side wall 85a that defines an upper impeller region 94 within the housing body 85. The annular gap 92 provides an air flow path 96 from the impeller 95 to the collection section 86. A radial outlet 97 conduit extends from the collection section 86 to provide a flow of air 98 from the impeller.

[0059] Blower 80 includes an upper housing portion ("upper housing") 81 including a plate 82 having a central air inlet aperture 82a (see Figs. 10, 11) and ribs 82b extending radially across the plate across the central air inlet aperture 82a to the hub. Ribs 82b are shown exposed in Fig. 11. Alternatively, as shown in an alternative embodiment in Fig. 13A, ribs 82b can be warped at the central hub 200. The warping reduces interaction with the impeller blades. In the particular embodiment shown in Fig. 13, each of the ribs includes a radial portion and a warping portion. Each warping portion extends along an axis that transverses the longitudinal axis of its respective radial portion. Each radial portion extends from the periphery of the plate to the outer edge of the central hub, and each warping portion extends from the outer edge of a central connector that connects to all of the other warping portions. Between each adjacent buckled portion, an opening is formed to allow air to flow to the motor. In other embodiments, the buckled portion of each rib 82 may be curved at the central hub region to minimize interaction with the impeller blades. Although FIG. 11 and FIGS. 13A-13C show five ribs, it will be understood that a variety of numbers of ribs may be provided, for example, three, five, or nine ribs. It may be advantageous to have an odd number of ribs so that the ribs provide a stable support base for the hood 83. As can be seen in FIG. 11 and FIGS. 13A-13C, the ribs 82b may be equiangularly disposed. The upper housing 81 may further include an engagement feature configured to orient and / or attach the upper housing 81 to the hood 83.

[0060] As can be seen in Figure 11, the plate 82 may be joined to the cylindrical side 85a by a bayonet joint 201, although a friction fit or other joint could be used. The hood 83 rests on the ribs. The ribs 82b set the hood 83 away from the plate to allow air to reach the impeller 95 and provide an air passage 99 to the air inlet aperture 82a. In use, air flow 9 enters the inlet. The ribs 82b also extend to and support a central upper hub 84 in the central aperture 82a, the upper hub also including a central aperture 84a.

[0061] The motor assembly 88 is assembled to the inner motor area 87. The motor stator support 101 is disposed in an annular opening in the motor area 87 and forms the base of the motor 88 sub-housing. The motor stator support 101 has a contoured annular periphery 101a that is disposed in a corresponding annular rebate / shelf 86c in the inner collector wall 86a. The motor stator support 101 also has a number of ribs 101b that extend radially from the annular periphery 101c to a bottom hub 101d having a central aperture 101e that receives a bearing race 110. As previously mentioned, the top hub 84 is supported by the hood ribs and has a central aperture 84a that receives the bearing race 110. The bearing race may be as described in the previous embodiment. In an alternative form, plain bearings or bushings may be used instead. A shaft 111 is supported in each bearing race 110 between the top hub 84 and the bottom hub 101d and extends from the top hub 84 through a central aperture 92 in the center plate 91. The shaft is solid, but may alternatively be hollow or partially hollow as described below. Stub axles 112 at either end of the shaft 111 support the shaft in each bearing 110. The annular periphery of the motor stator support also has a cylindrical sidewall 101f and defines a region 114 for concentrically supporting an annular / toroidal motor stator 89 including an annular stacked lamination core 89a with toroidal windings 89b. An annular / toroidal magnet 90 is supported concentrically on the shaft 111 and is concentrically disposed within the motor stator / motor stator region. An impeller 95 is supported on the shaft 111 and is housed within the impeller region 94 of the body 85. The impeller 95 may be any of those previously described. The impeller may be coupled onto or integrally formed with shaft 111. Shaft 111 may be of similar diameter as the shaft in the conventional topology, allowing for a rigid mechanical coupling of the impeller.

[0062] In operation, the impeller rotates and draws air through the central aperture, forcing the air around the annular gap, into the volume, and out the radial outlets.

[0063] This embodiment has the same advantages as those described in the previous embodiment.

[0064] The shaft 111 / stub axle 112 / bearings 110 arrangement of this embodiment is an inverted arrangement of the previous embodiment. Rather than bearings 110 being supported in shaft 111 and stub axle 112 being supported in upper / lower housings or hubs, in this embodiment, stub axle 112 is on shaft 111 and bearings 110 are in top hub 84 and bottom hub 101.

[0065] Each of the stub axles extends from the respective upper and lower ends of the shaft to a distal end. The stub axles extend away from one another. Each of the stub axles is substantially cylindrical in shape. In other embodiments, one or both of the stub axles are reduced or decreased in diameter as they extend away from the respective upper and lower ends of the shaft. The distal end of each stub axle is rounded. However, in other embodiments, the distal end of one or both of the stub axles is substantially flat. Each stub axle also includes a shoulder formed by a flange or step. In other embodiments, the shoulder is formed by a taper of the stub axle. The shoulder is located at or near the proximal end of each stub axle on the shaft. The top and bottom bearings engage the shoulder or each stub axle to limit axial movement of the bearing arrangement toward the shaft. Each of the top hub 84 and bottom hub 101 has a shoulder in opposing relationship to each respective stub axle shoulder. Each hub shoulder is formed as a recess or step in the inner surface of the hub. In other embodiments, the hub shoulder is formed by a taper in the inner surface of the hub. Upper and lower bearings also engage each hub shoulder such that they are captured between the respective hub shoulder and the respective stub axle shoulder.

[0066] In all embodiments, the arrangement is such that the bearings and stub axle arrangement couple the shaft to the upper / top and lower / bottom supports of the blower. The bearings and shafts can have other similar configurations (but in this embodiment the shaft need not be hollow), and thus the arrangement still provides the same advantages as the previous embodiment. The shaft can be of similar diameter as the shaft in the conventional topology, allowing for a rigid mechanical coupling of the impeller. However, since the stub axle is thinner than the shaft and can extend into the bearing, the diameter of the shaft is not affected by the inner diameter of the bearing. The outer diameter of the shaft can therefore be of any suitable size to allow for a rigid coupling of the impeller, for example about 5 mm, or alternatively about 3 mm to about 5 mm. Since the bearings are separate from the shaft, large diameter shafts can still be used without any bearing diameter size effect. The bearing size (e.g. diameter size) can therefore be selected based on the acceptable bearing speed. Similarly, the magnet / rotor 90 is pressed into the shaft. The same advantage applies here in that the shaft can be appropriately sized to allow for a firm connection.

[0067] The above embodiments show some examples of shaft, stub axle and bearing arrangement configurations that provide the advantages of the present invention. However, these embodiments are not exhaustive. More generally, it will be understood that other embodiments having any combination of the following configurations are also possible. Bearings in the shaft or alternatively on the top / bottom supports, Stub axles in the top / bottom supports or alternatively stub axles on the shaft, Hollow, partially hollow or solid shafts.

[0068] As an example and with reference to FIG. 12A, in some embodiments the blower has a hollow shaft 27, bearings 28 at both ends of the shaft, and stub axles 29a, 29b on the top / bottom supports.

[0069] As another example, and referring to Figure 12B, in some embodiments, a blower has a solid shaft 111, stub axles 112 at both ends of the shaft 111, and bearings 110 on the top / bottom supports. As shown in Figure 12B, the impeller stub axles 29a, 29b are rigid, and the top / bottom supports have elastic "cups" 220 to receive the bearings. The elastic material of the cups 220 is thin and only visible in cross section. Alternatively, as previously described, the stub axles 29a, 29b are made of an elastic material.

[0070] As another example and with reference to Figure 12C, in some embodiments the blower has a partially hollow shaft 210, bearings 28 at both ends of the shaft, and stub axles 29a, 29b on the top / bottom supports. In these embodiments, the shaft has recesses formed in each end of the shaft. The bearings and stub axles are at least partially received within respective recesses in the shaft.

[0071] The above embodiments show various configurations of inlet / outlet topologies. Various combinations of inlet and outlet topologies can be incorporated into any of the above embodiments. For example, in some embodiments, the blower can have an axial inlet A / axial outlet B topology (ribs 82b are different in each case), as shown in Figures 13A, 13B. In other embodiments, the blower can have an axial inlet A / radial outlet B / 97 topology, as shown in Figure 11. In other embodiments, the blower can have an axial inlet A / tangential outlet C / 230 topology, as shown in Figure 13C.

[0072] Other motor topologies are possible and those described are merely exemplary. For example, brushed or brushless DC motors, AC motors, inductance motors, or variable reluctance motors may be used. The rotor and motor stator may take other forms than those described.

[0073] The described embodiments have several advantages. The described embodiments provide a blower with a reduced footprint, both in profile and / or plan. The small footprint allows for a small housing. One reason for the small footprint is that the airflow stator allows for the omission of the volute, reducing the overall diameter of the blower while also increasing the ratio of blade length to housing diameter (i.e., the space for the blade length is not reduced by the presence of the volute, allowing more of the available footprint diameter to be used for the blade length compared to a housing with a volute).

[0074] Embodiments also allow for the use of smaller impellers (i.e. smaller diameter, thickness and / or overall weight), which in turn results in smaller / lighter blowers and / or blowers with less inertia. The smaller / lighter topology allows for the blower to be portable, miniaturized and / or used in head or mask mounted CPAP, high flow therapy or other respiratory devices.

[0075] As an example, the impeller may have a diameter of about 47 mm inside a ring of about 48 mm diameter, providing a blade length to housing diameter ratio of 98%. Another example would be about 18 mm blades in a housing of about 20 mm radius, a ratio of 90%. These are merely examples, other diameters are possible. A typical container / footprint for a blower is: Diameter: ≦53mm, Height: ≦21mm, Weight: ≦about 50g, or ≦about 47g (e.g., 27g) It could be.

[0076] Optionally, the impeller comprises: -Thickness of about 3mm or less A diameter of about 48 mm or less, or more preferably 48.4 mm; -Weight less than 3 grams has.

[0077] Other dimensions will become apparent upon reading this specification. It is preferred to maximize the blade to housing ratio.

[0078] Small impellers of these dimensions are not suitable for use in the above mentioned applications because, when operated at normal speeds (revolutions per minute), their airflow characteristics are insufficient (e.g., the flow rate and / or pressure generated by small impellers of this nature is not sufficient) to provide the required treatment. Furthermore, it has not been possible to drive these impellers at high speeds to generate the required flow rate and / or pressure, as these speeds bring several drawbacks. For example, when increasing the speed, the bearings operate at higher speeds and / or temperatures. This necessitates the use of specialized bearings such as ceramics, more expensive air bearings or hydrodynamic bearings. In order to reduce the bearing speed, smaller bearing races and bearings must be used. This necessitates reducing the shaft diameter so that the shaft can still pass through the center of the bearing race. When using smaller shafts, it is much more difficult to mount the impeller and / or rotor magnets, for example by integral design or friction fit. Manufacturing tolerances become too tight to make this feasible. Thus, accommodating small impellers has not been feasible until now. Another alternative is to use a blower with multiple impeller stages, but this is more expensive, larger and more difficult to manufacture.

[0079] This embodiment is able to overcome these challenges and allows the use of a smaller impeller in a single stage blower. The shaft used is hollow or at least partially hollow. The bearings are mounted inside the shaft. This allows two things: first, the impeller and / or rotor (or magnets) can be assembled or mounted in the usual way on the shaft, allowing the shaft diameter to be the same or similar dimensions as mentioned above, and second, since the bearings are located inside, it allows the use of smaller bearings (while still having the same diameter shaft). This therefore allows the impeller to rotate faster and generate the required flow and / or pressure with a smaller impeller. However, even though the impeller / shaft is operating at high speed, the smaller bearing operates at a lower peripheral speed (or higher angular speed) compared to the larger bearings traditionally used, avoiding the high speed challenges mentioned above. The stub axle therefore allows the connection of the bearings to the inner race, and the springiness / elasticity of the stub axle allows the springiness as the shaft rotates. This arrangement also reduces or eliminates eddy currents in the shaft and / or bearings, which can degrade the bearings.

[0080] Additionally, increasing the number and / or size of stub blades and air inlets allows for greater pressure to be generated from a shorter blade length.

[0081] The axial exit eliminates the need for a tangential exit duct, which can increase the blower footprint.

[0082] This arrangement also allows for a single stage axial-in / axial-out blower that provides a reduced footprint or lower profile. The described embodiment also has reduced dimensions due to the lack of swirl. The airflow stator ring creates static pressure. The axial airflow inlet allows for cooling of the motor stator.

Claims

1. Housing and a motor core within the housing; an impeller coupled to the rotor via a shaft; Including, The impeller is Hub and a blade extending from the hub; A stub blade; An annular ring; wherein the annular ring supports the stub blades.

2. The blower of claim 1 , wherein the annular ring is formed within the blade.

3. The blower of claim 1 , wherein the annular ring extends between the blades.

4. 3. The blower of claim 2, wherein the annular ring has an edge oriented toward the outlet for axially directing air.

5. The blower of claim 1 , wherein the blade further includes a vertical flat portion extending from the hub.

6. The blower of claim 1 , wherein the stub blade extends partway along the hub.

7. The blower of claim 1 , wherein the stub blades are spaced apart from one another.

8. The blower of claim 1 , wherein the stub blades are swept forward.

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