I L LU S T RAT E D S O U R C E B 0 0 K of ME C H A N I CAL C 0 M P 0 N E NTS

SECTION 6

EALS Rubber Seals for Oil Retention

Non-Rubbing Seals for Oil Retention

How to Seal Air Ducts that Separate

More Seals for Ducting that Separate Window Awning Unit Sealing

Window Casement Unit Seals

Multiple Seals & Bonding for Dam Retrofitting

6-2

6-4

6-6

6-8

6-10

6-1 1

6-12

6-2

Rubbing Seals for Oil Retention David C. Spaulding, JR.

Rubbing seals cover all applications where a positive sliding contact exists between the seal and either the rotating or stationary member. They are limited as to type of operation and speed because of the friction between the contacting surfaces and they should not be used in

One piece or

]

Seals & Packings 6-3

abrasive surroundings. Types that are held against the rotating member by spring pressure can be used where there is a pressure head of fluids within the assembly or on the exterior. For high pressure stuffing box and O-ring type seals are used. O-rings are also used for zero leakage.

Bronze ,bearing I \ \

Housing

- Shaft

I \ \

Housing

haft

-.L I- (- - - - -/Garter or stomped - -)

Bronze bearing Housing 4austing stud ,/and nul

FIG. &Rubbing seals, of the type shown, (A), have wide- spread use in all types of equipment. The spring tension and sealing ring material may be varied so that a variety of applieations can be handled. Small units can be had where the 0. D. is the same as the 0. D. of the sleeve bearing, (B), thus eliminating the counterboring operation on the housing. The seal may be reversed and used to keep foreign matter out of the assembly. A drain hole may be provided to earry away surplus lubricant. Retention is by press fit on the outside diameter.

FIG. 5-Rubbing seals of the stuffing box type (A) , are used where high pressure are encountered. It can be used for all types of motion and the packing material can be varied de- pending upon the fluid to be sealed and the application. For rotating motion some leakage is necessary so it cannot be used when permissible leakage is zero. O-rings can also be used for rotary motion if the speed is slow. Special designs use O-ring seals (B), when zero leakage is demanded for either stationary or reciprocating motion.

This ring is made of natural rubber or synthetic rubber de- pending on the type of solution resistance required. Synthetic rubber, such as buna or neoprene, is resistant to aromatic hydrocarbons, while natural rubber resists the action of alco- hol and glycerine.

0-rings ean be located either in the shaft or in the housing and any movement or pressure forces the ring to one side, thereby forming a tight seal.

-I . .\ ,o-r'"P ,', -.!$!--- I .

6-4

Non-Rubbing Seals for Oil Retention David C. Spaulding, JR.

There are two general types of seals: rubbing and non-rubbing. Non-rubbing seals use oil or grease to lubricate mating surfaces and exclude foreign matter by forcing the lubricant out between the bearing surfaces. These seals are not limited by operation or speed since

L ubricotion groove -----\.

Fig.!

Oil gathering Oil gathering

Grooves--

Fig.2

Fig. 1-Non-rubbing seal for grease lubrication. Grooves and housing are filled with grease at assembly or an automatic feed system can be incorporated. Seal offers protection against entrance of foreign matter because of the outward flow of grease through the labyrinth passages. Clearance between shaft and seal is about 1/64 inch.

Fig. 2-Non-rubbing seal for oil lubrication. Grooves can be located in bearing, (A), or in housing, (B). Grooves are connected to an oil return passage leading to a sump in housing. This keeps oil loss to a mini- mum and maintains a constant supply to the bearing. Design does not prevent entrance of foreign material. Radical clearance between shaft and seal is 1/64 inch.

Fig. 3-Seal for vertical hstallation. Circular groove picks up lubricant and feeds it to a spiral groove in bearing or shaft. Spiral feeds lubricant to top of bearing. Lubricant runs down between shaft and bear- ing. Design is effective when the shaft is rotating.

Fig. &Similar to Fig. 3 but used for a horizontal in- stallation to reduce leakage of lubricant, Straight groove feeds oil to the bearing. Circular groove col- lects oil and the spiral groove, .located in shaft or bearing, returns it to other end of hearing. Design prevents loss of oil by leakage at outside end.

Lubricant

-Shaft

Bronze

&I I ! - - - : I ,111 . I I I

O u i s i d L end of mechanism

Circular grc

.--Rotation counter

clockwise looking ot this end

Ei! F i g . 4 groove

Seals 8t Packings 6-5

friction is negligible. They are, however, often more expensive than rubbing seals since the shaft, bearing, or housing must be grooved to distribute the lubricant. Distribution over the bearing area is, however, better. Lubricants may be forced-fed or gravity-fed.

Fig. 5-Labyrinth seals offer good protection espe- cially at high speeds where the narrow zigzag passage is used in conjunction with centrifugal force. Oil and foreign matter are separated by slinger which limits oil flow past rotating member (A). Inner member (B) throws oil back to sump. Member (C ) throws out foreign matter.

Fig. 6-Non-rubbing seal for oil lubrication. Shaft rotation throws lubricant into the inboard groove ( B ) in the housing and is returned to the oil sump. First slinger ( D ) throws foreign material out of the assem- bly. Secnnd slinger (0) feeds foreign material out through groove (A) and hole at (C). Lubricant feeds between shaft and bearing to housing grooves.

Fig. ?'-Reservoir type feed for grease lubrication. Grease is distributed in annular groove and feeds through holes in bearing to lubricate the shaft. Foreign matter can be excluded if clean grease is used. Grease will be lost through open bearing ends and assembly must be repacked periodically.

Fig. 8-Reservoir type feed for oil lubrication. Two bearings are used forming an oil reservoir between them. If porous wall type bearings are used oil will saturate and feed through bearings to the shaft. Outward flow of oil prevents entry of foreign mate- rial. Reservoir must be periodically refilled with new oil. Bearings are a press fit in the housing.

6-6

How to Seal Air Ducts that Separate These slip joints reseal and realign ducting that is often taken apart. They also take care of expansion, vibration, and joint locations difficult to reach.

James H. LaPointe

&-!=I SPLIT RUBBER TUBING AND EDGE-ROUED ANGLE

Bend ouf

Lip con keep contra/ gasket ond prevenf confoct wi th point, smoke, etc.

Sea/ and guide ' and protection

(3 PLAIN RUBBER TUBING OR SOLID RlNC IN COMPRESSION

Seals & Packings 6-7

A four or more guide brockefs -

I

/ I

[ - I FLAT RUBBER AND GUIDE BRACKETS FOR CENTERING

7 ? CONFINED RUBBER STRIP

f Heavy confocf

Angle CUT on rubber owoy

Voriofion from 2"

sea/ edge w i l l force from opening

Seam //A Mefa/ tubinu Held

Rive# or spof we/d

To ma. u hole

cLI/ METAL TUBING AS GUIDE

6-8

More Seals for Ducting - that Separates Six more seals for round ducts and others. Make sure the gasket material can withstand the ducted media.

James H. LaPointe

U U

WEOGE-GUIDE SEAL n 5

2 /

Hole reinforcemenf (doubler)

ROUND-BAR GUIDE SEALS AND VARIATIONS

Seals & Packings 6-9

u 0

NONCENTERING SEALS-FLAT RUBBER a A

SLIP SLEEVES THAT SEAL WITHOUT GASKETS

I

A B METAL TUBING GUIDE AND VARIATIONS

6- 10

Window Awning Unit Sealing Illustrated by Robert 0. Parmley

n

rn$'"L -LEFT JAMB-

A 'A I L I

- RIGHT JAMB-

/

, . - SILL - - HORIZONTAL MULLION-

Rubber Seal

Seals & Packings 6-11

Window Casement Unit Sealing Illustrated by Robert 0. Parmley

- RlGHf . JAMB-

A - STANDARD MULLION - I

PICTURE MULLION FOR 1 INSULATION GLASS

6-12

Table of ContentsConnectionsSection 6. Seals & PackingsRubber Seals for Oil Retention Non-Rubbing Seals for Oil Retention How to Seal Air Ducts that Separate More Seals for Ducting that Separate Window Awning Unit Sealing Window Casement Unit Seals Multiple Seals & Bonding for Dam Retrofitting