US2393944A

US2393944A - Sealing unit

Info

Publication number: US2393944A
Application number: US475883A
Authority: US
Inventors: Jr Herbert H Walley
Original assignee: STEVENSON ENGINEERING CORP
Current assignee: STEVENSON ENGINEERING Corp
Priority date: 1943-02-15
Filing date: 1943-02-15
Publication date: 1946-01-29
Anticipated expiration: 1963-01-29

Description

Jan' 29, 1946- H. H. wALLEY, JR l '2,393,944

SEALING UNIT Filed Feb. 15, 1943 llllllll ggwamlzl ,2 INVENTOR Patented '.Fan. 29, i946 SEALING UNIT Herbert H. Wailey, Jr., Newton, Mass., assignor to Stevenson Engineering Corporation, a corporation of Rhode Island Application February 15, 1943, Serial No. 475,883

4 Claims.

This invention relates to an independent sealing unit which may be positioned between two relatively rotating parts and which will utilize the pressure of the iiuid which is to be sealed to actuate one of its members for providing the desired sealing pressure.

In the use of a sealing unit such as shown in the Robert Stevenson Patent No. 2,321,871; June 15, 1943, with which I am familiar, the replacement of the sealing sleeve in the unit reqr .res a complete detachment of the unit from working position for the removal of the sleeve should a fresh one be desired to be positioned in the unit. Such removal of the unit from its working position often scores the parts with which the casing engages and it becomes somewhat diilicult to get a tight t in replacing such a unit in working position. Further,l in the use of such a unit abovementioned it is necessary to stock complete assemblies including the sleeve for supply to the trade.

One of the objects of this invention is to provide a fluid seal in a unit consisting of several assembled parts so that the unit may be taken as a whole and forced into position where the seal is to be provided.

Another object of this invention is to provide a unit which although complete and held so that all of its parts are assembled it may permit of any easy interchange of the sealing sleeve whereby diiierent size sleeves or sleeves of different materials may be easily and quickly substituted in the unit.

Another object of this invention is to provide an arrangement so that after the sealing unit is in working position it will be possible to remove a worn sleeve and substitute a fresh one therefor without removing all of the sealing unit from its working position.`

Other objects of the invention are those common with said patent of Robert Stevenson No. 2,321,871 which has been assigned to the same assignee as this application and with which seal I am familiar. l

With reference to the drawing:

Figure 1 is a central sectional view through the sealing unit and through the casing in which it is assembled showing the sleeve engaging a flange on a shaft and the -parts in working position;

Figure 2 is a view on substantially line 2-2 of Figure 1 of the unit alone;

Figures 3, 4, 5, 6, 7, and 8 are sectional views of each of the individual parts of the unit and shown collectively as an exploded arrangement of these several parts in their relation one to the other;

Figure 9 is a section showing the unit completely assembled before being placed in working position as' shown in Figure 1;

Figure 10 is a modified arrangement showing an inverse relation of the parts with the sleeve outside instead of inside of the body member.

In order to provide these improvements I hold the sleeve in the unit only by the friction of the soft packing which engages it but which enables me to remove the sleeve and provides sleeves of i different materials or different sizes as regards the sealing surface or shafts accommodated and assemble such sleeve with the remainder of the unit which may be carried as a stock part thus reducing the stock or inventory necessary while of the pa'rts upon the removal of the assembly retaining all of the advantage of the complete independent unit assembly heretofore enjoyed. Further, where the arrangement of parts is such that the sleeve may be withdrawn without removing the body from its working position I may in many cases eliminate the liability ofv scoring which is also of great advantage.

With reference to the drawing I have shown at I0 a fragmental portion of a casing which is concentrically arranged in relation to a shaft I I having a flange I2 thereon which is ground to provide a sealing surface I3. My unit is designated as a whole I 4 as shown in Figure 9 and consists of a body member I5 of cylindrical shape in which there is axially slidably positioned a sleeve I6 also generally cylindrical and provided with a sealing face I1 at one end thereof. This sleeve is reduced in diameter as at I8 providing a shoulder I9 back from the sealing face while the inner bore of this sleeve 2liv is of a size to loosely fit about the shaft Il.

A soft packing 2| serves as a fluid controlling means and is of annular shape and snugly ts the reduced diameter I8 of the sleeve and also snugly fits the inner surface 22 of the body member I5 to prevent access of fluid to the opposite end of the sleeve. A retaining walll23 on the end of the body is also engaged by this packing. A washer 24 vengages the shoulder I9 of the sleeve and is sufciently loosely arranged with reference to the sleeve and the body so as to be relatively axially movable with reference to both of these. A spring 25 is located between this washer 24 and a washer 26 which engages the packing 2l so as to distribute the spring pressure evenly over the packing and by its resilient action urges the sleeve the sealing surface I3' of the flange I2'.

to cause its sealing surface I1 to abut the sealing surface I3 of the flange I2.

When the unit is free before positioning as shown in Fig. 9 in order to hold the parts assembled the movement of the washer 24 is limited by fingers 21 bent inwardly from thebody I5 so as to engage the washer 24 at spaced points around its periphery and serve as a holding means therefor.

The arrangement which is provided however permits a sleeve I6 being forced outwardly or to the left as shown in the drawing by a pressure which will overcome the friction of the soft packing which is exerted upon it. This friction is not sufficient to prevent the action of the spring working but is suflicient to hold the sleeve in assembled position in the unit. By pressure which may be exerted by the hand this sleeve may be forced out of the unit and a fresh one replaced or one which may be of a different material may be utilized. It is sometimes desirable to use A bronze or alloy sealing sleeves, in other cases carbon sealing sleeves. By this removal sleeves which have different size sealing faces may be used or sleeves which have different size bores for the accommodation of different shafts as shown in Figure 1 may be used.

It will be apparent that when in free position the sealing face I1 of the sleeve must project a substantial distance beyond the holding fingers 21 so that when the unit is in assembled Working position as shown in Figure 1 the shoulder of the sleeve will force the spring into compressed position and still be inwardly of the fingers 21. This being the desirable construction although it will be apparent that in certain relationships such as shown in Figure l this need not necessarily be the case. The sleeve is prevented from rotation relative to thebody by a slot 28 in the sleeve and finger 29 on the body extending therein.

The fluid to be sealed will press upon the shoulder I9 or washer 24 engaging the same to force the sleeve into sealing position. The effective area pressed upon will be the difference between the large diameter of the sleeve and the Ireduced portion I8 thereof. A chamber 30 is provided to receive the fluid to be sealed which chamber is partly bounded by said body and partly by said sleeve. y

Referring to Figure 10 an inversion of parts is illustrated there being indicated a casing I' and a shaft Il therein. The casing is provided with a flange I2 having a ground sealing surface I3'. The sealing unit is designated generally I4' and consists of a casing I5' and a sleeve I6 having a sealing face I1' which will engage The sleeve is enlarged inA diameter as at I8' providing alshoulder I9' for engagement by the washer 24. A soft packing 2i' provides a seal between the casing I' and sleeve I6'. by engagement with the surface I8' and the surface 22' of the body member I5'. A washer 26".engages the soft packing 2| and a spring 25 `acts between the washer 26 and the annular washer 24' to urge the sleeve to cause the sealing surfaces I1' and I3 to engage. There is a wall 23' on'the body against which the soft packing also engages and this wall is extended into a slot 28 in the sleeve forming a finger 29'. In order to prevent the washer 2l' from moving beyond the body member I5' I provide a nange or plurality of fingers 21' to engage this washer and limit its movement.

This unit is forced into position tightly upon the shaft II' to a suiilcient extent so that when the sealing surfaces engage the sleeve will be forced inwardly to an extent necessary to'compress the spring and move the washer 24' away from the fingers 21. The fluid will press upon the shoulder to urge the sleeve into sealing engagement. The sleeve may be drawn from the unit 'by overcoming the friction of the soft packing 2i' as heretofore mentioned in connection with the other form of `the invention.

I claim:

1. An 'independent sealing unit for preventing leakage of uid between relatively rotatable parts, one of said parts presenting an annular sealing surface, said sealing unit comprising a concentrically arranged body member and sleeve, said body member being of a dimension to be snugly pressing on said sleeve to urge it toward sealing position, an annular washer between and axially movable with reference to said sleeve and body and engageable with said shoulder, and holding means on said body extending toward said sleeve to be engaged by said washer and prevent separation of said washer from said unit, the sealing face of said sleeve being located to project beyond said holding means whereby the shoulder and washer of said sleeve are moved away from said holding means when the unit is in operating position.

2. A sealing unit as set forth in claim l wherein said shoulder on the sleeve extends radially inwardly.

3. A sealing unit as set forth in claim 1 wherein said shoulder on the sleeve extends radially outwardly.

4. An independent sealing unit comprising a body member, an annular packing means, an annular washer and an annular spring between said HERBERT H. WALLE'Y, JR.