Patent US3771906A successfully refreshed from Google Patents.
US3771906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature control of stator/rotor fit in helical gear pumps
Assignee: Robbins & Myers
•
Filing: 1972-06-05
•
Granted: 1973-11-13
•
Expires: 1992-06-05
Abstract
Abstract Loss of capacity in a helical gear pump resulting from wear of parts is restored by raising the temperature of the stator, or by raising the temperature of the stator and also the temperature of the fluid being pumped. Regardless of the state of wear, the capacity of a helical gear pump operating against elevated discharge pressures is improved by raising the temperature or temperatures as above, whereby to produce a tighter fit between the elements. Various alternative means for raising the temperature or temperatures are disclosed.
Inventors
- 👤 J Bourke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 20:28
CPC Classifications
F; F04; F04C; F04C15/00; F04C15/0096
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
77 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, a temperature sensing element embedded in said rubber stator, means for heating said rubber stator in order to expand the stator and produce a tighter fit between said stator and said rotor, and control means for said heating means responsive to sensings of said sensing element.
Claim 2
Dependent Claim
77 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, a temperature sensing element embedded in said rubber stator, means for heating said rubber stator in order to expand the stator and produce a tighter fit between said stator and said rotor, and control means for said heating means responsive to sensings of said sensing element.
Claim 3
Dependent Claim
24 words
A helical gear pump according to claim 1, wherein said stator is heated by means of an electrical heating element surrounding said metallic casing.
Claim 4
Dependent Claim
30 words
A helical gear pump according to claim 1, wherein said metallic casing is provided with a jacket for a heat transfer fluid, and said stator is heated by said fluid.
Claim 5
Dependent Claim
19 words
A helical gear pump according to claim 1, wherein said stator is heated by heating the fluid being pumped.
Claim 6
Dependent Claim
25 words
A helical gear pump according to claim 4, wherein the fluid being pumped is heated by steam introduced into the suction port of a pump.
Claim 7
Dependent Claim
28 words
A helical gear pump according to claim 4, wherein the fluid being pumped is heated by an electric heating coil disposed in the suction port of a pump.
Claim 8
Independent Claim
62 words
The method of compensating for stator wear in a helical gear pump having a working chaMber formed by a metallic rotor eccentrically arranged in a rubber stator, said stator confined within a metallic casing, which includes the steps of heating said stator to cause expansion thereof to enhance the rotor/stator fit, and basing the temperature increment upon the amount of stator wear.
Claim 9
Independent Claim
62 words
The method of compensating for stator wear in a helical gear pump having a working chaMber formed by a metallic rotor eccentrically arranged in a rubber stator, said stator confined within a metallic casing, which includes the steps of heating said stator to cause expansion thereof to enhance the rotor/stator fit, and basing the temperature increment upon the amount of stator wear.
Claim 10
Dependent Claim
18 words
The method of claim 7, wherein said stator is heated by raising the ambient temperature adjacent said stator.
Claim 11
Dependent Claim
73 words
The method of claim 8, wherein the temperature increment is determined by the equation: t1 W(3.1416D + 8E) X 106/(139 di2 - 148.44D2 - 756DE - 18.5DW - 48EW) wherein t1 is the temperature increment in * F., D is the diameter of the rotor in inches, E is the eccentricity of the rotor in inches, di is the inside diameter of the metallic casing in inches, W is the wear in inches.
Claim 12
Dependent Claim
19 words
The method of claim 7 wherein said stator is heated by raising the temperature of the fluid being pumped.
Claim 13
Dependent Claim
74 words
The method of claim 10, wherein the temperature increment is determined by the equation: t2 W(3.1416D + 8E) X 106/(139 di2 - 139D2 - 756DE - 18.5DW - 48 EW) wherein t2 is the temperature increment in * F., D is the diameter of the rotor in inches, E is the eccentricity of the rotor in inches, di is the inside diameter of the metallic casing in inches, W is the wear in inches.
Claim 14
Dependent Claim
99 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, an electrical heating element surrounding said rubber stator to heat said rubber stator in order to expand the stator so as to produce a tighter fit between said stator and said rotor, flow meter means disposed at the discharge of the pump, means to change electrical current supplied to said heating element in response to a change in flow through said pump as determined by said flow meter.
Claim 15
Dependent Claim
99 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, an electrical heating element surrounding said rubber stator to heat said rubber stator in order to expand the stator so as to produce a tighter fit between said stator and said rotor, flow meter means disposed at the discharge of the pump, means to change electrical current supplied to said heating element in response to a change in flow through said pump as determined by said flow meter.
Claim 16
Dependent Claim
102 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, said casing provided with a jacket for a heat transfer fluid to heat said stator in order to expand the stator so as to produce a tight fit between said stator and said rotor, flow meter means disposed at the discharge of the pump, means to change flow of heat transfer fluid to said jacket in response to a change in flow through the pump as determined by said flow meter.
Claim 17
Dependent Claim
102 words
A helical gear pump having a suction port and a discharge port, a working chamber formed by a metallic rotor and a rubber stator, said stator confined within a metallic casing, said casing provided with a jacket for a heat transfer fluid to heat said stator in order to expand the stator so as to produce a tight fit between said stator and said rotor, flow meter means disposed at the discharge of the pump, means to change flow of heat transfer fluid to said jacket in response to a change in flow through the pump as determined by said flow meter.
References Cited (Backward Citations)
US2796029A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |