Patent US3604819A successfully refreshed from Google Patents.
US3604819A
Expired / Lapsed
US
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Impeller shaft assembly
Assignee: United States Steel Corp
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Filing: 1969-10-14
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Granted: 1971-09-14
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Expires: 1989-10-14
Abstract
Abstract An impeller shaft assembly for a fan operating at high temperatures in the range from ambient temperature to a highoperating temperature is disclosed. The impeller shaft assembly has a metal shaft having at one end a connector portion of reduced nonround cross section. The reduced cross section has rounded corners. The shaft has a tapered portion provided with a taper toward the one end adjacent the connector portion. The shaft has a first coefficient of expansion. A ceramic impeller is disposed on the shaft and is provided with a connector aperture adapted to receive and frictionally engage the connector portion with a predetermined cold clearance. The impeller is provided with a tapered aperture adjacent the connector aperture, is adapted to receive the tapered portion with one cold clearance (of a cold clearance greater than the first predetermined cold clearance, a cold clearance equal to the first predetermined cold clearance and a cold clearance less than the first predetermined cold clearance) and defines an impeller shoulder with the connector aperture. The impeller shoulder is engageable with the shaft shoulder. The impeller has a second coefficient of expansion less than the first coefficient of expansion. Drive means are connected to the shaft to cause rotation of the shaft and the impeller at high speed. The shaft and the impeller are rotated by the drive means at the high speed and at the high temperature so that the predetermined cold clearance and the one cold clearance are reduced to a limit which approaches but never reaches zero.
Inventors
- 👤 Francis J Krahe
- 👤 Lawrence J Serena
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:59
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/26; F04D29/28; F04D29/281; C; C21; C21D; C21D9/00; C21D9/52; C21D9/54; C21D9/663; C21D9/673
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
262 words
An impeller shaft assembly for a fan operating at high temperatures in the range of ambient temperature to a highoperating temperature, said impeller shaft assembly having: a. a metal shaft having at one end a connector portion of reduced nonround cross section; 1. said reduced cross section having rounded corners, 2. said shaft having a tapered portion provided with a taper toward said one end adjacent said connector portion and defining a shaft shoulder with said connector portion, 3. said shaft having a first coefficient of expansion, b. a ceramic impeller disposed on said shaft and provided with a connector aperture having a nonround cross section and adapted to receive said connector portion with a predetermined cold clearance, said connector aperture (58a) contacting said connector portion (58) along at least two contact lines (59); 1. said impeller being provided with a tapered aperture adjacent said connector aperture, adapted to receive said tapered portion with another cold clearance, and defining an impeller shoulder with said connector aperture, a. said impeller shoulder being engageable with said shaft shoulder, 2. said impeller having a second coefficient of expansion less than said first coefficient of expansion, c. drive means connected to said shaft to cause said shaft to frictionally engage said impeller thereby causing rotation of said shaft and said impeller at high speed; d. said shaft and said impeller being rotated by said drive means at high speed and at said high temperature so that said predetermined cold clearance and said other cold clearance are reduced to a limit which approaches but never reaches zero.
Claim 2
Dependent Claim
262 words
An impeller shaft assembly for a fan operating at high temperatures in the range of ambient temperature to a highoperating temperature, said impeller shaft assembly having: a. a metal shaft having at one end a connector portion of reduced nonround cross section; 1. said reduced cross section having rounded corners, 2. said shaft having a tapered portion provided with a taper toward said one end adjacent said connector portion and defining a shaft shoulder with said connector portion, 3. said shaft having a first coefficient of expansion, b. a ceramic impeller disposed on said shaft and provided with a connector aperture having a nonround cross section and adapted to receive said connector portion with a predetermined cold clearance, said connector aperture (58a) contacting said connector portion (58) along at least two contact lines (59); 1. said impeller being provided with a tapered aperture adjacent said connector aperture, adapted to receive said tapered portion with another cold clearance, and defining an impeller shoulder with said connector aperture, a. said impeller shoulder being engageable with said shaft shoulder, 2. said impeller having a second coefficient of expansion less than said first coefficient of expansion, c. drive means connected to said shaft to cause said shaft to frictionally engage said impeller thereby causing rotation of said shaft and said impeller at high speed; d. said shaft and said impeller being rotated by said drive means at high speed and at said high temperature so that said predetermined cold clearance and said other cold clearance are reduced to a limit which approaches but never reaches zero.
Claim 3
Dependent Claim
27 words
said shaft having a tapered portion provided with a taper toward said one end adjacent said connector portion and defining a shaft shoulder with said connector portion,
Claim 4
Dependent Claim
27 words
said shaft having a tapered portion provided with a taper toward said one end adjacent said connector portion and defining a shaft shoulder with said connector portion,
Claim 5
Dependent Claim
85 words
said impeller having a second coefficient of expansion less than said first coefficient of expansion, c. drive means connected to said shaft to cause said shaft to frictionally engage said impeller thereby causing rotation of said shaft and said impeller at high speed; d. said shaft and said impeller being rotated by said drive means at high speed and at said high temperature so that said predetermined cold clearance and said other cold clearance are reduced to a limit which approaches but never reaches zero.
Claim 6
Dependent Claim
85 words
said impeller having a second coefficient of expansion less than said first coefficient of expansion, c. drive means connected to said shaft to cause said shaft to frictionally engage said impeller thereby causing rotation of said shaft and said impeller at high speed; d. said shaft and said impeller being rotated by said drive means at high speed and at said high temperature so that said predetermined cold clearance and said other cold clearance are reduced to a limit which approaches but never reaches zero.
Claim 7
Dependent Claim
17 words
The impeller shaft assembly recited in claim 1 wherein said reduced nonround cross section is generally elliptical.
Claim 8
Dependent Claim
23 words
The impeller shaft assembly recited in claim 1 wherein said reduced nonround cross section is generally polygonal and is provided with rounded corners.
Claim 9
Dependent Claim
55 words
said shaft having a first coefficient of expansion, b. a ceramic impeller disposed on said shaft and provided with a connector aperture having a nonround cross section and adapted to receive said connector portion with a predetermined cold clearance, said connector aperture (58a) contacting said connector portion (58) along at least two contact lines (59);
Claim 10
Dependent Claim
55 words
said shaft having a first coefficient of expansion, b. a ceramic impeller disposed on said shaft and provided with a connector aperture having a nonround cross section and adapted to receive said connector portion with a predetermined cold clearance, said connector aperture (58a) contacting said connector portion (58) along at least two contact lines (59);
Claim 11
Dependent Claim
15 words
The impeller shaft assembly recited in claim 1 wherein said metal shaft is stainless steel.
Claim 12
Dependent Claim
48 words
The impeller shaft assembly recited in claim 1 wherein said ceramic impeller has silica in the range of about 4.3 to 14.3 percent by weight; alumina in the range of about 85.0 to 95.0 percent by weight and trace quantities of titania, iron oxide, lime, magnesia and alkalies.
Claim 13
Dependent Claim
22 words
The impeller shaft assembly recited in claim 5 wherein said first predetermined cold clearance is in the range of about 0.035-0.050 inch.
Claim 14
Dependent Claim
16 words
The impeller shaft assembly recited in claim 1 wherein said limit is greater than 0.005 inch.
Claim 15
Dependent Claim
26 words
The impeller shaft assembly recited in claim 1 and having space means between said shaft shoulder and said impeller shoulder to maintain said predetermined cold clearance.
Claim 16
Dependent Claim
28 words
The impeller shaft assembly recited in claim 1 and having retaining means on said connector portion and engageable with said impeller to retain said impeller on said shaft.
Claim 17
Dependent Claim
16 words
The impeller shaft assembly recited in Claim 1 wherein said taper is less than about 20*.
Claim 18
Dependent Claim
30 words
The impeller shaft assembly recited in claim 1 wherein said stainless steel has a minimum nickel content of about 35 percent and a minimum chromium content of about 15 percent.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |