US4421457A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffuser of centrifugal fluid machine
Assignee: Hitachi Ltd
•
Filing: 1981-02-06
•
Granted: 1983-12-20
•
Expires: 2001-02-06
Abstract
Abstract A vaneless diffuser disposed on the outer periphery of an impeller of a centrifugal compressor and including a pair of opposed diffuser plates of a disk shape defining therebetween a fluid channel is formed with a plurality of guide vanes extending from the inlet of the diffuser to its outlet. The guide vanes which are disposed on at least one of the pair of diffuser plates and extend immediately from the outlet of the impeller in the direction of flow of a fluid through the fluid channel has a height smaller than one-half the width of the fluid channel and gradually decreasing in going from the inlet of the diffuser toward its outlet.
Inventors
- 👤 Yoichi Yoshinaga
- 👤 Hiromi Kobayashi
- 👤 Shinjiro Ueda
- 👤 Yoshihiro Takada
- 👤 Hideo Nishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:44
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/40; F04D29/42; F04D29/44; F04D29/441; F04D29/444; F05; F05D; F05D2250/00; F05D2250/50; F05D2250/52
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
141 words
A diffuser of a centrifugal fluid machine having an inlet and an outlet and comprising a pair of opposed diffuser plates, and a fluid channel defined between said pair of opposed diffuser plates, such diffuser being characterized by further comprising a plurality of guide vanes formed on at least one of said diffuser plates extending along the flow of a fluid in said fluid channel, said guide vanes each having a height smaller than one-half the width of said fluid channel and gradually decreasing in going from the inlet of the diffuser toward the outlet thereof, whereby a distorted flow at the inlet of the diffuser will be brought into a substantially uniform flow pattern in an inlet portion of the diffuser and generation of secondary flow in an outlet portion of the diffuser will be avoided, by said guide vanes.
Claim 2
Dependent Claim
141 words
A diffuser of a centrifugal fluid machine having an inlet and an outlet and comprising a pair of opposed diffuser plates, and a fluid channel defined between said pair of opposed diffuser plates, such diffuser being characterized by further comprising a plurality of guide vanes formed on at least one of said diffuser plates extending along the flow of a fluid in said fluid channel, said guide vanes each having a height smaller than one-half the width of said fluid channel and gradually decreasing in going from the inlet of the diffuser toward the outlet thereof, whereby a distorted flow at the inlet of the diffuser will be brought into a substantially uniform flow pattern in an inlet portion of the diffuser and generation of secondary flow in an outlet portion of the diffuser will be avoided, by said guide vanes.
Claim 3
Dependent Claim
140 words
A diffuser of a centrifugal fluid machine having an inlet and an outlet and comprising a pair of opposed diffuser plates, and a fluid channel defined between said pair of diffuser plates, such diffuser being characterized by further comprising a plurality of guide grooves formed on at least one of said diffuser plates and extending along the flow of a fluid in said fluid channel, said guide grooves having a depth smaller than one-half the width of said fluid channel and gradually decreasing in going from the inlet of the diffuser toward the outlet thereof, whereby a distorted flow at the inlet of the diffuser will be brought into a substantially uniform flow pattern in an inlet portion of the diffuser and generation of secondary flow in an outlet portion of the diffuser will be avoided, by said guide vanes.
Claim 4
Dependent Claim
140 words
A diffuser of a centrifugal fluid machine having an inlet and an outlet and comprising a pair of opposed diffuser plates, and a fluid channel defined between said pair of diffuser plates, such diffuser being characterized by further comprising a plurality of guide grooves formed on at least one of said diffuser plates and extending along the flow of a fluid in said fluid channel, said guide grooves having a depth smaller than one-half the width of said fluid channel and gradually decreasing in going from the inlet of the diffuser toward the outlet thereof, whereby a distorted flow at the inlet of the diffuser will be brought into a substantially uniform flow pattern in an inlet portion of the diffuser and generation of secondary flow in an outlet portion of the diffuser will be avoided, by said guide vanes.
Claim 5
Dependent Claim
35 words
A diffuser of a centrifugal fluid machine as set forth in claim 1 or 2, wherein said guide vanes or guide grooves are located only on the diffuser plate on the side of a shroud.
Claim 6
Dependent Claim
50 words
A diffuser of a centrifugal fluid machine as set forth in claim 3, wherein said guide vanes or guide grooves are mounted such that their inlet angle is equal to or smaller than the design flow angle and that their outlet angle are substantially equal to the design flow angle.
Claim 7
Dependent Claim
33 words
A diffuser of a centrifugal fluid machine as set forth in claim 1 or 2, wherein said guide vanes or guide grooves are located on both of said pair of opposed diffuser plates.
Claim 8
Dependent Claim
50 words
A diffuser of a centrifugal fluid machine as set forth in claim 5, wherein the height of the guide vanes or the depth of the guide grooves is smaller on the diffuser plate on the side of the hub than on the diffuser plate on the side of the shroud.
Claim 9
Dependent Claim
50 words
A diffuser of a centrifugal fluid machine as set forth in claim 6, wherein said guide vanes or guide grooves are mounted such that their inlet angle is equal to or smaller than the design flow angle and that their outlet angle are substantially equal to the design flow angle.
Claim 10
Dependent Claim
50 words
A diffuser of a centrifugal fluid machine as set forth in claim 5, wherein said guide vanes or guide grooves are mounted such that their inlet angle is equal to or smaller than the design flow angle and that their outlet angle are substantially equal to the design flow angle.
Claim 11
Dependent Claim
52 words
A diffuser of a centrifugal fluid machine as set forth in claim 1 or 2, wherein said guide vanes or guide grooves are mounted such that their inlet angle is equal to or smaller than the design flow angle and that their outlet angle are substantially equal to the design flow angle.
Claim 12
Dependent Claim
41 words
A diffuser of a centrifugal fluid machine according to claim 1 or 2, wherein the height of the guide vanes or guide grooves decreases from a maximum value at said inlet to a minimum value at the outlet of the diffuser.
Claim 13
Dependent Claim
18 words
A diffuser of a centrifugal fluid machine according to claim 10, wherein said minimum valve is substantially zero.
Claim 14
Dependent Claim
22 words
A diffuser of a centrifugal fluid machine according to claim 10, wherein said minimum value is 1/4 to 1/2 said maximum value.
Claim 15
Dependent Claim
44 words
A diffuser of a centrifugal machine as set forth in claim 1 or 2, wherein a maximum width of said fluid channel at said inlet of the diffuser is at least equal to a maximum width of said fluid channel at the diffuser outlet.
Claim 16
Dependent Claim
26 words
A diffuser of a centrifugal machine as set forth in claim 13, wherein the maximum width of the fluid channel remains constant throughout the length thereof.
Claim 17
Dependent Claim
25 words
A diffuser of a centrifugal machine as set forth in claim 13, wherein the maximum width of said fluid channel decreases throughout the length thereof.
Claim 18
Dependent Claim
39 words
A diffuser of a centrifugal machine as set forth in claim 15, wherein the maximum width of the fluid channel at said outlet of the diffuser is equal to a minimum width of the diffuser at the inlet thereof.
References Cited (Backward Citations)
DE1937395A1
Cited
US3692426A
Cited
SU419639A1
Cited
US3936225A
Cited
SU522343A1
Cited
SU526721A1
Cited
SU572586A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-19 | 1987-06-20 | 1987-12-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-19 | 1991-06-20 | 1991-12-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-19 | 1995-06-20 | 1995-12-20 | $7700.00 | Window Closed / Lapsed |