US2891808A

US2891808A - Oil-and-vapor shaft-seal

Info

Publication number: US2891808A
Application number: US666928A
Authority: US
Inventors: William S Richardson
Original assignee: Falk Corp
Current assignee: Rexnord Industries LLC
Priority date: 1957-06-20
Filing date: 1957-06-20
Publication date: 1959-06-23
Anticipated expiration: 1976-06-23

Description

June 23, 1959 w. s. RICHARDSON 2,891,308

g .OIL-AND-VAPOR SHAFT-SEAL Y Filed Junezo, 1957 I 4 Sheets-Sheet 1 INVENTOR: WILLIAM S. RICHARDSON ATTORNEYS I June 23, 1959' w. S.'R1CHARDSON OIL-AND-VAPOR SHAFT-SEAL v 4' Sheets-Sheet '5 Filed June 2 0. 1957 INVENTOR, WILLIAM S.RICHARDSQN ATTORNEYS June 1959 w. s. RICHARDSON OIL-AND-VAPOR SHAF'Ii -SEAL 4 Sheets-Sheet. 4

Filed June 20, 195"! ll-l-Illlnll INVENTORI AI TORNEYS United States Patent OIL-AND-VAPOR SHAFT-SEAL William S. Richardson, Fox Point, Wis., assignor to The Falk Corporation, Milwaukee, Wis., a corporation of Wisconsin Application June 20, 1957, Serial No. 666,928

4 Claims. (Cl. 286-10) This invention relates to an oil-and-vapor shaft-seal, and more particularly to mechanism for preventing the escape of vaporized lubricating oil from the housings of power-transmission gear units which have rotating shafts extending from the housings.

In such a unit the rapid rotation of certain gears is apt to churn-up some of the lubricant into a vapor, which then breathes out around the input and output shafts, more particularly the former, and then congeals on the outside of the housing and of adjacent objects, producing a messy condition similar to that which would be cause by an oil-leak. Conventional oil-seals which are efiective to prevent the escape of liquid oil have proved ineffective to prevent this escape of vaporized oil.

Accordingly the principal object of the present invention is to produce a modified oil-seal which will serve to prevent this escape of vaporized oil.

Other objects and advantages will appear in the description which follows.

In the description, reference is made to the accompanying drawings, forming a part hereof, in which there is shown, by way of illustration and not of limitation, a certain specific form in which the article of manufacture of the present invention may be embodied.

In the drawings:

Fig. 1 is a vertical section of part of one wall of the housing and associated parts, of the present invention, as viewed from the line 11 of Fig. 2.

Fig. 2 is a vertical section, as viewed from the line 22 of Fig. 1.

Fig. 3 is a vertical section, as viewed from the line 3--3 of Fig. 1.

Fig. 4 is a vertical section, as viewed from the line 4-4 of Fig. 1.

Fig. 5 is a vertical section, as viewed from the line 5-5 of Fig. 1.

Fig. 6 is a plan view of the base of the housing, showing certain associated parts in section, as viewed from the line 6-6 of Fig. 1.

Fig. 7 is a vertical section, as viewed from the line 77 of Figs. 2 and 6.

Throughout the description, the same reference-numeral is applied to the same member or similar members.

Referring now to the drawings, it will be seen that 11 is the base of the housing and 12 is the cover of the housing, joining each other along a horizontal split 13.

In a large hole 14 in the housing there fits a bearingcage 15, containing a babbitt bearing 16, in which shaft 17 is journaled. Closely surrounding this shaft is oilretainer 18, which is secured to the outer face of the housing in any convenient manner.

The essential parts of retainer 18 are as follows. An inner chamber 19, bounded by the wall of the housing and by retainer 18 surrounds the shaft. Next outwardly comes a fine labyrinth 20, consisting of a number of fine-pitch alternating annular grooves and ridges, the latter surrounding and closely adjacent the shaft. On the upper retainer wall of oil-return chamber 19, there is an oil-pocket 21, with a hole 22 in the bottom of which there is a drain-hole 22, which connects with labyrinth 20 adjacent the inner end thereof. As shown, this hole connects with the inner groove of the labyrinth.

Next outwardly from this labyrinth, there is an oilseal, comprising two oil-seal chambers (a large one 23, and a small one 24, the former having a constricted portion 25), delimited by the outer face of labyrinth 20 and two annular ridges 26, surrounding and closely adjacent shaft 17.

The bottom of small oil-seal chamber 24 connects with large oil-seal chamber 23 through hole 27. The bottom of large oil-seal chamber 23 connects with inner chamber 19 through hole 28, where dam 29 sets up a trap 30.

Lubricating oil under pressure, from a source not shown, passes through hole 31 which lies along the juncture 13 of base 11 and cover 12 of the housing, to annular passage 32 on the periphery of bearing cage 15. Thence part of the oil proceeds radially, through holes 33, to lubricate bearing 16; and part proceeds through hole 34 and bleeder hole 35 into inner chamber 19, where it is squirted across (as indicated by arrows) into oilpocket 21; whence it flows, through hole 22, into labyrinth 20, under constant head determined by the height of oil-pocket 21.

This method of conveying oil, via oil-pocket 21, to labyrinth 20 under gravity head, is sufficient to overcome the pressure of the vapor in chamber 19, and thus prevents the outward escape of this vapor along shaft 17. The alternative of piping the oil direct to labyrinth 20 would not be so satisfactory, inasmuch as the oil-pressure necessary to distribute the oil for lubrication purposes would be more than necessary for vapor-seal purposes, and would force such an amount of oil out along shaft 17 as would be difiicult for the outer oil-

seals

24 and 25 to take care of.

Most of the oil which oozes out through bearing 16, or drops from the squirt-stream, or overflows from oilpocket 21, or flows into inner chamber 19 from labyrinth 20, or congeals from the vapor, is thrown off centrifugally by shaft 17, and ends-up in the bottom of inner chamber 19, whence it passes into housing 11, through hole 36.

The oil under constant gravity head in labyrinth 20 mostly passes back into inner chamber 19 between labyrinth 20 and the surface of shaft 17; and, being under higher pressure than any oil-vapor escaping from the housing, serves to force this vapor back into the housing through hole 36. Some of the oil from oil-pocket 21 passes outwardly between labyrinth 20 and the surface of shaft 17, thus creating a further seal against any escape of vapor.

As this oil proceeds outwardly beyond labyrinth 20, it is thrown centrifugally by the rotation of shaft 17, into oil-

seal chambers

23 and 24, collects in the bottom of chamber 24, and thence flows into the bottom of inner chamber 19, and into housing 11 through hole 36.

To summarize the seals it will be seen that inner chamber 19 and

outer chambers

23 and 24 are oil-seals, and labyrinth 20 is a vapor-seal. In view of the fact that the use of oil in the labyrinth for vapor-seal purposes adds oil to be taken care of beyond the labyrinth, at

least two oil seals beyond the labyrinth are highly desirable.

Drain-hole 28, at the bottom of oil-retainer 18, is submerged in oil by means of an internal darn 29 to form trap 30, to prevent any vapor from by-passing the vapori 3 seal efiected by the oil in labyrinth 2!). Leaving hole 36 untrapped is highly advisable, to insure against a build-up of vapor in inner chamber 19, which would create a pressure suificient to counteract the inward pressure of the oil in labyrinth 2-0.

It will be readily evident from the foregoing description that the present invention affords a novel and useful mechanism for preventing the escape of vaporized lubricating oil from the housings of power-transmission gear units which have rotating shafts extending from the housings.

It should be understood that the invention could likewise be employed with respect to other shafts which protrude from the housing.

Now that one embodiment of the invention has been shown and described, it is to be understood that the invention is not to be limited to the specific form or arrangement of parts herein shown and described.

What is claimed is:

1. An oil-and-vapor shaft-seal for preventing the escape of vaporized lubricating oil from the housing of a power-transmission gear unit, the combination, with the housing and a shaft journaled therein and projecting therefrom, comprising: an inner chamber surrounding and open to the projecting portion of the shaft adjacent the housing; beyond this chamber a labyrinth consisting of alternating fine-pitch annular grooves and ridges, surrounding the shaft, the grooves being open to the shaft, and the ridges being closely adjacent the shaft; means for introducing lubricating oil under pressure into the labyrinth intermediate its ends; beyond the labyrinth at least one oil-seal chamber surrounding and open to the shaft, and delimited by annular ridges surrounding and closely adjacent the shaft; and conduit means for conveying away such oil as collects in the'oil-seal chambers and the inner chamber; wherein the means for introducing oil to the labyrinth comprises: an oil-pocket above the labyrinth, the upper end of this pocket being open into the inner chamber; an exit conduit leading from this pocket into the labyrinth; and a conduit for transmitting oil to the pocket; whereby the gravity head of the oil in the pocket determines the pressure of the oil admitted into the labyrinth.

2. An oil-and-vapor shaft-seal according to claim 1, wherein the conduit for transmitting oil into the pocket ends within the inner chamber, and is so located and directed with respect to the pocket that oil under pressure squirts from the end of the conduit into the open upper end of the pocket.

3. An oil-and-vapor shaft-seal according to claim 1, wherein the conduit means for conveying oil away from the oil-seal chambers conveys this oil into the inner chamber and thence into the interior of the housing, and includes a trap where it enters the inner chamber, Whereby to prevent vapor in the inner chamber from by-passing the labyrinth.

4. An oil-and-vapor shaft-seal according to claim 2, wherein the conduit means for conveying oil away from the oil-seal chambers conveys this oil into the inner chamber and thence into the interior of the housing, and includes a trap where it enters the inner chamber, whereby to prevent vapor in the inner chamber from by-passing the labyrinth.

Stroebel Apr. 30, 1940 Thompson May 13, 1941