Seal for a joint or juncture – Seal between relatively movable parts – Relatively rotatable radially extending sealing face member
Patent
1989-10-30
1992-01-07
Cuchlinski, Jr., William A.
Seal for a joint or juncture
Seal between relatively movable parts
Relatively rotatable radially extending sealing face member
277152, 277164, F16J 1532
Patent
active
050784102
DESCRIPTION:
BRIEF SUMMARY
This invention relates to sealing means for the prevention of fluid leakage between the rotating and stationary members of centrifugal fluid pumps, turbines, agitators and the like.
Conventionally, most centrifugal pumps prevent or control fluid leakage, both during operation and while stationary, by the use of interfacial seals. These seals contain stationary and rotating sealing surfaces which are held in sliding contact with a controlled surface pressure to minimise fluid leakage past the sealing surfaces. Interfacial seals may be subdivided into two classes dependent upon the disposition of the sealing surfaces relative to the rotating shaft axis, viz. axial seals and radial seals. Both types of seals are widely used in centrifugal fluid pumps.
Axial seals encompass the broad class of mechanical end face seals in which the sealing surfaces are flat, rigid, and disposed normally to the shaft axis. These seals have been widely applied to centrifugal pump, turbine and agitator shaft sealing applications with gas, liquid and slurries as the pumped product, and have been developed in an extensive range of variant designs.
Radial seals define the class of shaft seals in which the sealing contact surface is cylindrical and concentric with the pump shaft axis. The stuffing box is a commonly used seal of this type in which impermeable and compliant packing material is contained and pressurised in an annular cavity surrounding the shaft by an axially adjusted gland member. This type of seal is extensively applied in both liquid and slurry centrifugal pumps. Seals of this type belong to the class of radial seals.
The abrasive nature of pumped fluid in centrifugal slurry pumps commonly results in severe wear of shaft seal elements resulting in increased fluid leakage and maintenance requirements. Even with clean liquid pumps, sealing elements wear and require adjustment. These problems have resulted in the development of hydrodynamic shaft seals which are incorporated in many centrifugal slurry pumps. These invariably comprise auxiliary pumping vanes on the impeller which develop a hydrodynamic fluid pressure to eliminate leakage from the pump casing. During pump operation fluid leakage is eliminated or substantially reduced with this type of noncontacting seal. Supplementary sealing means are required additional to the hydrodynamic seal to prevent leakage from the pump when stationary. Such static seals are commonly interfacial seals of the radial type. Although fluid leakage, in operation, is effectively prevented or controlled by the hydrodynamic seal, the continuous sliding contact at the static seal surfaces results in abrasive wear at these surfaces with resultant loss of static sealing performance.
The aim of this invention is to overcome, by novel means, a number of limitations associated with conventional centrifugal fluid pump seals and to improve current sealing technology, particularly in relation to, but not limited to, centrifugal slurry pumps (where abrasive wear is greatest), and in accordance with the following objectives:
(a) to increase the effective operating life of pump seals between maintenance overhauls;
(b) to reduce abrasive wear rate at the sealing surfaces;
(c) to provide a seal suitable for use under the most adverse fluid conditions, including heterogeneous fluids typical of coarse abrasive slurries;
(d) to permit substantial axial displacement between the stationary and rotating sealing surfaces; and
(e) to provide a seal with automatic loading of sealing surfaces and requiring no manual adjustment of loading either during installation or in operation.
The present invention in one broad form comprises a centrifugal sealing member for preventing leakage between a rotating member and a stationary member with an outer cylindrical surface, said sealing member comprising an annular support member and an inner annular engaging member, said support member being adapted to be mounted on said rotating member, with said annular engaging member being adapted to sealingly engage around the said
REFERENCES:
patent: 2352336 (1944-06-01), Martin et al.
patent: 2786699 (1957-03-01), Kurti
patent: 2943873 (1960-07-01), Hamm et al.
patent: 3117796 (1964-01-01), Liebig
patent: 3256027 (1966-06-01), Chapel
patent: 3627390 (1971-12-01), Irwin
patent: 4277072 (1981-07-01), Forch
patent: 4426086 (1984-01-01), Fournie et al.
patent: 4428587 (1984-01-01), Forch
Grzina Anthony
Martin, deceased Denis J.
Mitchell Philip N.
Warman Charles H.
Cuchlinski Jr. William A.
Cummings Scott
Warman International Limited
LandOfFree
Centrifugal seal does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Centrifugal seal, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Centrifugal seal will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-816897