Fluid energy transfer device
A rotary chambered fluid energy-transfer device includes a housing with a central portion having a bore formed therein and an end plate forming an arcuate inlet passage, with a radial height and a circumferential extent. The device also includes an outer rotor rotatable in the central portion bore with a female gear profile formed in a radial portion defining a plurality of roots and an inner rotor with a male gear profile defining a plurality of lobes in operative engagement with the outer rotor. A minimum radial distance between an outer rotor root and a corresponding inner rotor lobe define a duct end face proximate the end plate, wherein the duct end face has a radial height substantially equivalent to the inlet passage radial height at a leading edge of the inlet passage.
1. A method of manufacturing a high expansion ratio energy transfer device, the method comprising the steps of:
(a) providing a housing comprising:
(1) a central portion having a bore formed therein; and
(2) an end plate forming an arcuate inlet passage, the inlet passage comprising a radial height and a circumferential extent;
(b) providing an outer rotor rotatable in the central portion bore, the outer rotor comprising a female gear profile formed in a radial portion defining a plurality of roots;
(c) providing an inner rotor with a male gear profile defining a plurality of lobes in operative engagement with the outer rotor; and
(d) forming a duct by maintaining a minimum radial distance between an outer rotor root and a corresponding inner rotor lobe, the duct comprising a radial height, a circumferential extent, and a depth to define a duct volume, wherein the duct radial height at a duct end face is substantially equivalent to the inlet passage radial height at a leading edge of the inlet passage.
2. The method of claim 1 , wherein the duct end face and the inlet passage are disposed at a substantially similar radial location.
3. The method of claim 2 further comprising the step of configuring an interface between the duct end face and the inlet passage to create an inlet passage open area profile as a function of outer rotor rotation that is substantially constant.
4. The method of claim 2 , wherein the inlet passage leading edge substantially matches a shape of a corresponding aligned portion of the outer rotor at the duct end face to provide substantially instantaneous inlet passage opening and a trailing edge that substantially matches a shape of a corresponding aligned portion of the outer rotor at the duct end face to provide substantially instantaneous inlet closing.
5. The method of claim 2 further comprising the step of defining the inlet passage circumferential extent to control an expansion ratio of the device.
6. The method of claim 2 further comprising the step of defining the inlet passage circumferential extent to control pulsing of the device.
7. The method of claim 2 further comprising the step of defining the inlet passage radial height to control flow into at least the duct volume via the inlet passage.
8. The method of claim 7 , wherein the inlet passage radial height defining step comprises defining an outer edge of the inlet passage by a rotational path of a root of the outer rotor and defining an inner edge of the inlet passage by a rotational path of a lobe tip of the inner rotor.
9. The method of claim 1 further comprising the step of modifying the outer rotor to control the duct volume.
10. The method of claim 9 , wherein the modification comprises altering an outer wall of each outer rotor root.
11. The method of claim 10 , wherein each outer wall is modified to vary in a radial direction as a function of depth and to be one of linear, concave, and convex.
12. The method of claim 9 , wherein the modification comprises altering at least one side wall of each outer rotor root.
13. The method of claim 12 , wherein each altered side wall is modified to vary in a circumferential direction as a function of depth and to be one of linear, concave, and convex.
14. A rotary chambered fluid energy-transfer device comprising:
(a) a housing comprising:
(1) a central portion having a bore formed therein; and
(2) an end plate forming an arcuate inlet passage, the inlet passage comprising a radial height and a circumferential extent;
(b) an outer rotor rotatable in the central portion bore, the outer rotor comprising a female gear profile formed in a radial portion defining a plurality of roots; and
(c) an inner rotor with a male gear profile defining a plurality of lobes in operative engagement with the outer rotor, forming a minimum radial distance between an outer rotor root and a corresponding inner rotor lobe defining a duct end face proximate the end plate, wherein the duct end face comprises a radial height substantially equivalent to the inlet passage radial height at a leading edge of the inlet passage.
15. The fluid energy transfer device of claim 14 , wherein the duct end face and the inlet passage are disposed at a substantially similar radial location.
16. The fluid energy transfer device of claim 15 , wherein the leading edge substantially matches a shape of a corresponding aligned portion of the outer rotor at the duct end face to provide substantially instantaneous inlet passage opening.
17. The fluid energy transfer device of claim 15 , wherein the inlet passage comprises a trailing edge that substantially matches a shape of a corresponding aligned portion of the outer rotor at the duct end face to provide substantially instantaneous inlet passage closing.
18. The fluid energy transfer device of claim 14 , wherein the inlet passage radial height is substantially constant across the inlet passage circumferential extent.
19. The fluid energy transfer device of claim 14 , wherein the inlet passage radial height varies across the inlet passage circumferential extent.
20. The fluid energy transfer device of claim 19 , wherein an outer edge of the inlet passage is defined by a rotational path of a root of the outer rotor and an inner edge of the inlet passage is defined by a rotational path of a lobe tip of the inner rotor.
21. The fluid energy transfer device of claim 14 , wherein the inlet passage circumferential extent extends in a range up to about 180 degrees of arc.
22. The fluid energy transfer device of claim 21 , wherein the inlet passage circumferential extent extends in a range up to about a circumferential extent defined by adjacent roots of the outer rotor.
23. The fluid energy transfer device of claim 14 , wherein an outer wall of each root varies in a radial direction as a function of depth.
24. The fluid energy transfer device of claim 23 , wherein the outer wall is selected from the group consisting of linear, concave, and convex.
25. The fluid energy transfer device of claim 14 , wherein at least one sidewall of each root varies in a circumferential direction as a function of depth.
26. The fluid energy transfer device of claim 25 , wherein the at least one sidewall is selected from the group consisting of linear, concave, and convex.
27. The fluid energy transfer device of claim 14 , wherein an outer wall of each root is substantially constant in a radial direction as a function of depth.
28. The fluid energy-transfer device of claim 14 , wherein the device is adapted for use as a compressor.
29. The fluid energy-transfer device of claim 14 , wherein the end plate further forms an outlet passage and the inlet passage and the outlet passage are configured for a predetermined compression of a fluid.