US3756738A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Centrifugal pump with differential thermal expansion relief means
Assignee: Rexnord Industries LLC
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Filing: 1971-10-22
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Granted: 1973-09-04
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Expires: 1991-10-22
Abstract
Abstract A centrifugal blower having one or more impellers mounted on a shaft for rotation therewith with the impellers and shaft being made of materials having different thermal coefficients of expansion and the impeller hubs being provided with means for relieving compressive stresses generated by differential expansion. The stress relieving means comprises disk-shaped channels formed in the impeller hubs to permit the central portions of the impeller hubs to be resiliently deformed to relieve the compressive stresses, thereby avoiding shaft distortion which produces vibration of the blower.
Inventors
- 👤 W Lee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:41
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/02; F01D5/025; F04; F04D; F04D29/00; F04D29/26; F04D29/266
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
128 words
A centrifugal blower comprising in combination a housing, a rotatable shaft mounted in said housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith and locking means for locking said impeller hubs in fixed relation to one another and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, at least one of said impeller hubs having an internal peripheral channel formed therein adjacent to said shaft to form a resilient deformable hub portion whereby axial stresses generated by differential thermal expansion of said shaft and hubs and consequent bending stresses generated in the hub portions of the impellers are relieved.
Claim 2
Dependent Claim
128 words
A centrifugal blower comprising in combination a housing, a rotatable shaft mounted in said housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith and locking means for locking said impeller hubs in fixed relation to one another and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, at least one of said impeller hubs having an internal peripheral channel formed therein adjacent to said shaft to form a resilient deformable hub portion whereby axial stresses generated by differential thermal expansion of said shaft and hubs and consequent bending stresses generated in the hub portions of the impellers are relieved.
Claim 3
Dependent Claim
164 words
A centrifugal blower comprising in combination a housing, a rotatable shaft Mounted in said housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith and locking means for locking said impeller hubs in fixed relation to one another and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, said impeller hubs having front faces with inlet ports formed therein and rear faces substantially perpendicular to said shaft, at least one of said hubs having a disk-shaped internal peripheral channel formed therein close to the rear face of said hub whereby the portion of said hub between said channel and the rear face of the said hub is resiliently and axially deformed to relieve axial and bending stresses generated in the hub portions of the impellers by differential thermal expansion of said hub portions and said shaft.
Claim 4
Dependent Claim
164 words
A centrifugal blower comprising in combination a housing, a rotatable shaft Mounted in said housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith and locking means for locking said impeller hubs in fixed relation to one another and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, said impeller hubs having front faces with inlet ports formed therein and rear faces substantially perpendicular to said shaft, at least one of said hubs having a disk-shaped internal peripheral channel formed therein close to the rear face of said hub whereby the portion of said hub between said channel and the rear face of the said hub is resiliently and axially deformed to relieve axial and bending stresses generated in the hub portions of the impellers by differential thermal expansion of said hub portions and said shaft.
Claim 5
Dependent Claim
20 words
A centrifugal blower according to claim 2 wherein each of said impeller hubs is provided with one of said channels.
Claim 6
Dependent Claim
27 words
A centrifugal blower according to claim 2 wherein said channel extends radially into said hub in a direction substantially perpendicular to the rotational axis of said shaft.
Claim 7
Dependent Claim
27 words
A centrifugal blower according to claim 2 wherein spacer rings are mounted on said shaft between said impeller hubs to maintain a predetermined spacing between said hubs.
Claim 8
Dependent Claim
169 words
A centrifugal blower comprising in combination a housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith, spacer rings mounted on said shaft between said impellers for maintaining a predetermined spacing between said impeller hubs and locking means on said shaft for locking said impeller hubs and spacer rings together and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, said impeller hubs having front faces with inlet ports formed therein and rear faces substantially perpendicular to said shaft, said hubs having internal peripheral channels formed therein close to the rear faces of said hubs, whereby the portion of said hubs between said channels and the rear faces of said hubs are resiliently and axially deformed to relieve axial and bending stresses generated in the hub portions of the impellers by differential thermal expansion of said hub portions and said shaft.
Claim 9
Dependent Claim
169 words
A centrifugal blower comprising in combination a housing, a plurality of impellers within said housing having hubs mounted on and secured to said shaft for rotation therewith, spacer rings mounted on said shaft between said impellers for maintaining a predetermined spacing between said impeller hubs and locking means on said shaft for locking said impeller hubs and spacer rings together and holding them against axial motion in respect to said shaft, said impellers being made of a material having a greater thermal coefficient of expansion than said shaft, said impeller hubs having front faces with inlet ports formed therein and rear faces substantially perpendicular to said shaft, said hubs having internal peripheral channels formed therein close to the rear faces of said hubs, whereby the portion of said hubs between said channels and the rear faces of said hubs are resiliently and axially deformed to relieve axial and bending stresses generated in the hub portions of the impellers by differential thermal expansion of said hub portions and said shaft.
Claim 10
Dependent Claim
27 words
A centrifugal blower according to claim 2 wherein said peripheral channel extends radially into its hub to a point axially opposite the inlet port of said hub.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |