Impeller and motor assembly
A breathing assistance apparatus has a pressurised gases source featuring a lightweight impeller with a plastic shaft. The impeller is shroudless. The plastic shaft is supported within the stator by a bearing structure. A resilient motor mount couples the stator and the housing and provide compliance and/or damping for the motor.
1. A breathing assistance apparatus comprising:
a pressurised gases source comprising:
a housing,
a gases inlet,
a gases outlet adapted to emit pressurised gases to an outlet of the breathing assistance apparatus,
a motor comprising:
a rotor including a central opening including a ledge,
a homogeneous rotatable plastic shaft contacting the ledge, thereby coupling the rotatable plastic shaft to the rotor,
at least one bearing structure to support the rotatable plastic shaft within a stator, the at least one bearing structure having one or more flexible and/or resilient bearing mounts to provide compliance and/or preload and/or damping for the rotatable plastic shaft, and
a lightweight impeller coupled to the rotatable plastic shaft.
2. The breathing assistance apparatus according to claim 1 , further comprising a flexible and/or resilient motor mount that couples the stator and the housing to provide compliance and/or damping for the motor.
3. The breathing assistance apparatus according to claim 1 , wherein the ledge spans a perimeter of the central opening.
4. The breathing assistance apparatus according to claim 1 , wherein the rotatable plastic shaft engages with the ledge to prevent relative motion between the rotor and the rotatable plastic shaft.
5. The breathing assistance apparatus according to claim 1 , wherein the central opening includes at least one indent projecting outwardly from the center of the central opening into the rotor.
6. The breathing assistance apparatus according to claim 1 , wherein the rotor is formed from a magnet material.
7. The breathing assistance apparatus according to claim 1 , wherein the central opening comprises a central portion with at least one indent.
8. The breathing assistance apparatus according to claim 1 , wherein the central opening comprises a central portion with four indents.
9. The breathing assistance apparatus according to claim 1 , wherein the central opening comprises a central portion with at least two equally spaced indents.
10. The breathing assistance apparatus according to claim 1 , wherein the central opening comprises a profiled edge through a central cross-section providing the ledge.
11. The breathing assistance apparatus according to claim 1 , wherein the ledge is a stepped ledge.
12. The breathing assistance apparatus according to claim 1 , wherein the opening comprises three different diameters.
13. The breathing assistance apparatus according to claim 1 , wherein the plastic shaft is overmoulded onto the rotor.
14. The breathing assistance apparatus according to claim 1 , wherein the plastic shaft comprise a location profile for coupling with the lightweight impeller.
15. The breathing assistance apparatus according to claim 1 , wherein the plastic shaft comprise a hex for coupling with the lightweight impeller.
16. The breathing assistance apparatus according to claim 1 , wherein the plastic shaft comprises acety or polypropylene.
17. The breathing assistance apparatus according to claim 1 , wherein the impeller is a shroudless impeller.
18. The breathing assistance apparatus according to claim 1 , wherein the impeller has a mass less than two grams.
19. The breathing assistance apparatus according to claim 1 , wherein the bearing mounts comprise an elastomeric material.
20. The breathing assistance apparatus according to claim 1 , wherein the ledge is a first ledge, further comprising a second ledge on an opposite side of the rotor as the first ledge.