Seal for a joint or juncture – Seal between relatively movable parts – Relatively rotatable radially extending sealing face member
Patent
1993-12-10
1996-06-25
DePumpo, Daniel G.
Seal for a joint or juncture
Seal between relatively movable parts
Relatively rotatable radially extending sealing face member
277 81R, F16J 1534
Patent
active
055293174
DESCRIPTION:
BRIEF SUMMARY
The invention relates to a sliding ring seal, in the end side sealing faces of which there are made depressions, each depression having an endless edge within the region constantly covered by the sealing faces, the fluid which has penetrated between the sealing faces into the depressions from the space to be sealed being entrained by the rotating sliding face and both put under greater pressure and also brought as close as possible to the space to be sealed, so that the fluid flows back into the space to be sealed again, out of the depressions.
Generally, sliding ring seals seal a fluid (liquid or gas) by countering the fluid to be sealed with a high flow resistance produced by a very narrow sealing gap between their end side sealing faces, as a result of which the leakage flow penetrating through the gap is small. So that the sealing gap can always be kept very narrow during operation of a sliding ring seal, the axially movable sealing ring is pressed against the other sealing ring both by means of springs and by the pressure of the fluid to be sealed. Although the fluid penetrates into the sealing gap under capillary action, and possibly as a result of a difference in pressure, it can occur that the sealing faces touch one another in some regions temporarily, thus become heated and wear. In order to prevent disadvantages resulting from this, namely the failure of the seal as a result of overheating, fissure formation, decomposition of the fluid in the sealing gap and the formation of deposits, excessive wear, etc., there are in accordance with the prior art a plurality of measures which have the aim of producing and maintaining a load-bearing fluid pressure in the sealing gap and in this way of reliably separating the sealing faces and thus stably establishing a narrow sealing gap. These measures can be divided into the terms "hydrostatic" and "hydrodynamic" gap pressure production. In the case of hydrostatic gap pressure production, measures are taken which alter the average value of the pressure decreasing in the sealing gap from the pressure level in the space to be sealed to the pressure level of the surrounding space. In the hydrodynamic gap pressure production, measures are taken as a result of which the fluid which is entrained by the sealing face of the rotating sealing ring in the sealing gap is accumulated at local gap-narrowing locations, as a result of which the fluid pressure is increased, as in the case of a hydrodynamic sliding bearing. However, an increase in the gap pressure has a disadvantage which is considerable from a sealing technology point of view, namely an increase in the sealing gap with the consequence of an increase, often to a considerable extent, of leakage. With regard to environmental protection, however, there is nowadays a general wish to reduce leakage drastically and reliably in all sliding ring seals which seal "problem fluids". In order to stem leakage from hydrodynamically lubricated sliding ring seals, there are in accordance with the prior art special constructions, in which the fluid flow penetrating from the space to be sealed into the sealing gap is guided by means of particular structuring of the sealing faces such that some of it flows back into the said space. Disadvantages of known constructions having this mode of operation are their structure, which is complicated from a production point of view, the relatively large radial width of the sealing faces which is necessary because of production of the structures, and the fact that the depressions are open to the low-pressure side, as a result of which in principle leakage occurs with certain structural types when the shaft is at a standstill and there is a risk with other structural types that even small deformations of the sealing faces result in considerable leakage. In some constructions, the fluid is entrained in the wrong direction in partial regions of the sealing edge and leakage is thus produced. Another disadvantage of known constructions is the fact that their return action only functions in one di
REFERENCES:
patent: 3640541 (1972-02-01), Taschenberg
patent: 3822066 (1974-07-01), Keys
patent: 4407513 (1983-10-01), Takenaka
patent: 5090712 (1992-02-01), Pecht et al.
H. K. Muller, "Hydrodynamische Dichthilfen" bei Hochleistungs-Gleitringdichtungen, Abdichtung bewegter Maschinenteile, pp. 123-126 (no date available).
H. K. Muller, "Fluid Film Sealing," ASLE Education Course, May 1972, Houston, Texas.
Laurenson et al., "A Slot Fed Multirecess Hydrostatic Seal," Paper G2, 6th International Conference on Fluid Sealing, Feb. 27-Mar. 2, 1973, Munich, Germany.
DePumpo Daniel G.
Flexibox Limited
LandOfFree
Floating ring seal with return structures and process for making does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Floating ring seal with return structures and process for making, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Floating ring seal with return structures and process for making will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2184200