Multiple stage blowers and volutes therefor

• US 20050103339A1
• Filed: 06/10/2004
• Published: 05/19/2005
• Est. Priority Date: 12/10/2001
• Status: Active Grant

• Current Assignee: ResMed Pty Ltd. (ResMed Incorporated)
• Original Assignee: Resmed Limited (ResMed Incorporated)
• Inventors: Daly, Geoffrey Daniel, Lea, Stephen Anthony, Reed, Nicholas Jerome, Virr, Alexander, Fu, Timothy Tsun-Fai, Martin, Dion Charles Chewe, Puckeridge, Larry
• Granted Patent: US 8,517,012 B2
• Time in Patent Office: Days
• US Class Current: 128/204.180
• CPC Class Codes: A61M 16/0057 Pumps therefor
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 16/0875 Connecting tubes
• CPC Class Codes: A61M 16/107 in the inspiratory path
• CPC Class Codes: A61M 2205/42 Reducing noise
• CPC Class Codes: A61M 2205/82 Internal energy supply devices
• CPC Class Codes: F04D 17/122 the individual rotor discs being, one for each stage, on a common shaft and axially spaced, e.g. conventional centrifugal multi- stage compressors
• CPC Class Codes: F04D 17/125 the casing being vertically split
• CPC Class Codes: F04D 25/06 the pump being electrically driven F04D25/08 takes precedence
• CPC Class Codes: F04D 25/166 using fans
• CPC Class Codes: F04D 27/004 by varying driving speed
• CPC Class Codes: F04D 29/281 for fans or blowers
• CPC Class Codes: F04D 29/284 for compressors
• CPC Class Codes: F04D 29/4213 suction ports
• CPC Class Codes: F04D 29/4226 Fan casings
• CPC Class Codes: F04D 29/661 especially adapted for elastic fluid pumps
• CPC Class Codes: F04D 29/663 Sound attenuation
• CPC Class Codes: F05B 2240/14 Casings, housings, nacelles, gondels or the like, protecting or supporting assemblies there within
• CPC Class Codes: F05B 2240/30 : Characteristics of rotor blades, i.e. of any element transforming dynamic fluid energy to or from rotational energy and being attached to a rotor

Abstract

A multiple stage variable speed blower for Continuous Positive Airway Pressure (CPAP) ventilation of patients includes two impellers in the gas flow path that cooperatively pressurize gas to desired pressure and flow characteristics. Thus, the multiple stage blower can provide faster pressure response and desired flow characteristics over a narrower range of motor speeds, resulting in greater reliability and less acoustic noise.

Claims

1. A multiple stage blower comprising:

a first conduit adapted to transport air from an external inlet to an internal inlet, said first conduit having a spiral shape,

stationary flow guidance vanes positioned between the first conduit and the internal inlet, said stationary flow guidance vanes being adapted to change the direction of the air arriving at the vanes from primarily tangential to primarily radial,

a second conduit adapted to transport air from said internal inlet to an external outlet.

2. The blower of claim 1, wherein at least a portion of said first conduit has a decreasing cross-sectional area in the direction of airflow.

3. The blower of claim 1, wherein said stationary flow guidance vanes are aerofoil shaped.

4. The blower of claim 1, wherein said blower further comprises a motor, a first impeller operatively connected to said motor, and a second impeller operatively connected to said motor.

5. The blower of claim 4, wherein at least one of said first impeller and said second impeller has scalloped edges.

6. The blower of claim 1, further comprising a housing, said housing being disposed around said first conduit and said second conduit.

7. The blower of claim 6, wherein said housing has an outer casing and a rubber insert for said outer casing, said rubber insert at least partly defining said spiral conduit.

8. The blower of claim 7, wherein said outer casing is constructed from aluminum.

9. An enclosure for receiving the blower of claim 1.

10. The enclosure of claim 9, wherein said enclosure includes a flow meter positioned upstream from said external inlet.

11. The enclosure of claim 9, wherein the enclosure includes a main seal positioned between an enclosure base and an enclosure lid.

12. The enclosure of claim 11, wherein the main seal includes a plurality of apertures to allow the passage of motor wires.

13. The enclosure of claim 11, wherein the enclosure base and enclosure lid cooperate to form a muffling chamber and a blower chamber.

14. The enclosure of claim 13, wherein a flow meter is positioned upstream of the muffling chamber and the blower chamber.

15. An enclosure for a blower used in the administration of positive pressure ventilation of a patient, the enclosure including:

an enclosure base defining a blower chamber for the blower;

an enclosure lid provided to sealingly engage the enclosure base; and

an flow meter provided upstream of the blower chamber.

16. The enclosure of claim 15, further comprising an inlet connector provided to an inlet side of the flow meter.

17. The enclosure of claim 16, wherein the inlet connector includes an inlet end in communication with atmosphere.

18. The enclosure of claim 16, wherein the inlet connector defines a substantially linear path from atmosphere to the inlet side of the flow meter.

19. The enclosure of claim 16, wherein a path of air from an outlet side of the flow meter towards the blower chamber is substantially non-linear.

20. The enclosure of claim 19, wherein the path of air from a region downstream of the flow meter and into the blower chamber is substantially closed.

21. The enclosure of claim 16, wherein the inlet connector includes an upwardly sloping portion positioned below the inlet side of the flow meter.

22. The enclosure of claim 15, further comprising a main seal provided between the base and lid.

23. The enclosure of claim 22, wherein the main seal comprises a gasket having an upper groove to receive the lid and a lower groove to receive the base.

24. The enclosure of claim 22, wherein the main seal includes an inlet opening communicating between a flow meter fitting and a primary muffling chamber.

25. The enclosure of claim 22, wherein the main seal includes an outlet passage communicating between the blower chamber and an exterior outlet fitting.

26. The enclosure of claim 25, wherein the outlet passage is substantially linear.

27. The enclosure of claim 26, wherein the base includes a supplemental muffling chamber associated with the outlet passage.

28. The enclosure of claim 25, wherein the outlet passage includes a first end provided to the blower chamber, the first end including a blower outlet fitting and a relatively flexible portion of enlarged radius just downstream of the blower outlet fitting.

29. The enclosure of claim 15, wherein an inside portion of the lid includes at least one aperture to receive a positioning member provided to a top portion of the blower.

30. The enclosure of claim 29, wherein the positioning member includes at least one of a spring and a rubber/silicone suspension bush.

31. The enclosure of claim 15, further comprising a main seal between the lid and base.

32. The enclosure of claim 31, wherein the main seal defines a first wall section corresponding to the blower chamber, said wall section including a plurality of holes provided for the passage of one or more blower wires.

33. The enclosure of claim 32, wherein said wall section includes a plurality of fingers and adjacent pairs of said fingers together define individual ones of the holes.

34. The enclosure of claim 33, wherein each of the fingers is open ended to allow sliding insertion of the motor wires along the length of the fingers until the wires are seated in the respective apertures.

35. A motor for use with a blower, comprising:

a shaft;

an impeller mounted to the shaft and structured to rotate in close proximity to a volute wall; and

a sensor provided to sense movement of the impeller relative to the volute wall, wherein the sensor provides an indication if the impeller moves more than a predetermined amount towards the volute wall, so as to disable the motor before contact can occur between the impeller and the volute.

36. A blower comprising:

a motor provided with opposed first and second shafts;

first and second stage impellers provided to the first and second shafts, respectfully;

an inner casing to support the motor;

an outer casing to support the inner casing;

a substantially annular channel is provided between the inner and outer casings, wherein, in operation, gas is directed from the first stage impeller towards the second stage impeller via the substantially annular channel.