US1983392A

US1983392A - Shaft packing

Info

Publication number: US1983392A
Application number: US547809A
Authority: US
Inventors: Nilsson Richard
Original assignee: LESTO AB
Current assignee: LESTO AB
Priority date: 1930-07-03
Filing date: 1931-06-30
Publication date: 1934-12-04
Anticipated expiration: 1951-12-04

Description

Dec. 4, 1934.

R. NILSSON SHAFT PACKING Filed June 50, 1931 2 Sheets-Sheet l VEN OR ATTORNEY Dec.4,1934. A R. NILSSON 1,983,392. SHAFT PACKING 7 Filed June so, 1951 2 SheetS -Sheet 1;

Fig. 2

BY i

is AT lgNEY Patented Dec. '4; 19 3 4 j H H iwss This invention relate's t'o shaft packings and] particularly has reference "to packings'jfor shafts? extending from vessels, and more particularly to torpedo shaft packings" 'The invention is,

.5 however, also applicable to shafts of other kinds audit is possible to prevent leakage-of gases 1'51 axial pressure on' the ring in'ember's.

The nature of the invention will become apparent from "the fol lowing description taken in connection-With the accompanying drawings showing a-' torpedo designed in accordance with 20. the'invention' andformingpart ofthis' spe'ci'fica 0f'the-drawingsz j 1 i Fig. i 1 s a cross sectional -centerline view of- I 25 packings'according to the inventioni n -Fig. 2 1s a 'cr'o'sS-sectionalf View; on a larger; scale, of a part of the torpedo including ap'ack the stern portion of a torpedo provided-with i1 Figsu3 and4 show inexter'nal views one of 30. the packingringsf l 1! f *In Fig. 1. 1 the interior l ofithe torpedo is closed at the rear by -'means of bulkheads 2, ;3. The torpedo has two propellersf'rotating in opposite directionslw The rear propelle r 4' is mounted on {35, theihollow inner shaft 5 and the forepropeller 6 on'the shaft 7' surrounding the inner shaft: Both 'shafts extend throughthestern bulkhead 3. In order to prevent water from penetrating into the interiorof the torpedo, a packing 8 ac-' '40 cording to. the invention-is arranged between the shafts and awpacking 9:.is arranged between the outer shaft and the stationary parts of-the 1 torpedo.- Another packing 19 Dune same kindis arranged in immediate-proximity to the bulk-- {A51 head '2. Theobjectofthis packing is to prevent water from: penetrating. throughthe hollow inner shaft into the gearcompartment 10 in which pinionsll .andllZaremounted on shafts 5 and 7;.respectively; 5' "w 1.. a Q Q; .Before *describing the packings lin detail; it should be noted that the general arrangement is such thatany water whichrpossibly may penetrate through the rearshalv'es of i the J packings 8 and 91 passes through openings 13- between thehalves ,of fthe; packings into am'oil containing 'SHAFTHLPACKJNGFJ I I l mass Nils s on; siokao1atamissignorio Aktiebolaget [Jest-.0;"Stockholm,Sweden; a co r atlon "Jam; mam-51m. 54%,805 I Ge m n -July ,1 30 a.

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chamber14 and sinks o the bottom of the chamber, thus forcing a quantity of oil to leave the chamber'through one of the packings. A cylinder 15 in which a spring-loaded piston 16 is arranged, communicates on one side of said piston with the-outside Water-through openings 17 and-on-the 'other's'ide with the chamber 14 through an opening 18. By thisarrangement a counter-pressure is set up in chamber 141Which varies with-the pressure with which the outside water atdifierent positions "of depth of the torpedo tries to penetrate through the packings into the'interior of the torpedo. Thiscounter pressure which counteracts the penetration of the outside water, is'alw'ays somewhat higher than the outer .water pressure, This-is so because the pressure of the water'tending to leak pass the packing is measured by a column of water extending from the packing to the surface of the waterfwhile the pressure .of the liquid within chamber 14"tending to leak outis measured by a column of water extending from the packing to the surface, which is the same as the first mentionedcolumn and hence the two columns counterbalance each other, plus a column of water extending from the packing to the piston 16 at the bottom of thetorpedo minus a column of oilof equalheight." Inasmuch as the specific gravity-of -the oil is less than that of the water, the column of water outside the torpedo acting against piston 16 overbalances the column of oilinside and tends to force'the oil out through the packings around the shafts.

The hollowinner space of the inner propeller shaft 5 is connected'to the inner space of the torpedo through a valve 29 or some similar device of such kind thatit prevents the entrance of water into the torpedo but'on the other hand allows the exhaust gases from the driving machine to escape with as-small resistance as possible through-the inner shaft.

:;Fig. 2 illustrates the packing 8 between the shafts 5 and? on a larger scale. The leakage of water between the two shafts is prevented by ringinembersZO and '21. These rings are'made of resilient material and aresplit and their ends slotted so as to overlap, as is shown at 26in FigQ iw The inner diameter of rings 20 is such that the rings are expanded somewhat by shaft 5 and'hencethe inner surface of the rings are pressed tightly against the shaft, and leakage therebetween is prevented. The outer diameter of rings 21 is such that the rings are contracted somewhat by sleeves 22 secured to the outer shaft 7 and. hence the outer surface of the rings I en of the in sand between the same is provided a spiralsp ring, which acts in an axial direction on the. rings and keeps their side surfaces yieldingly' pressed against each other. By this arrangement a very good packing is obtained because any water penetrating from the outside is forced to pass through the spaces between the rings 20 and the sleeve 22 and between the rings 21 and the inner sha e asw l as' tw enth sid su faces. of:

all rings t ht pressed t eeth n Th rings 20. and 21 b in lot e afte the nner of piston ri s s a zfiwa canno leak a ound he split. h manne o form n the r n and he slot 261 of no s t ali p tance. It is, however, suitable to give the rings; re inne an out di meters in such man ner that the rings 20, after being mounted will be in tight alignment with the shaft 5 and the outer surfaces of rings 21, in tight alignment with the sleeves 22 or the outer shaft 7;.

If the shaftsrotate with a high number of revolutions, the pressure pressing the rings 20,

against the inner shaft 5 with which they. are

rotating, is decreased by the centrifugal force, whereby the. friction, between the shaft and the rings during operation is diminished, which circumstance, however, has, no influence. on the effectiveness of the packing, as. on rotation of the h ft a. decr as o pressure. ex s s at the stern ends of the shafts, so that. the outside water has less tendency to penetrate into the torpedo than would be the case ifthe torpedo were submerged in the water with itsv shafts stationary.

The packings according to the; invention, of course. may pr vent the penetration, of water from without as well; as the leakage of oil from the interior of the torpedo outwardly.

As above mentionedleakage water after pass ing the rear half of the pack-ing sinks through the opening 13 tothe bottom of: the oil chamber 14, thus raising, the, oil pressure in, this cham- 3 ber and forcing a quantity of; the oil, corresponding to the inflowing. water, to enter. through the half of the packing facing thegear case 10,where it contributes tothe oil ng 0f the gearing. This applies also-v to the packing 19, the oil chamber 27 of, which is located below and is connected through a pipe 28 to. oil chamber 14.

The manner in which the different packing rings are pressed axially against each other is. of no vital importance. Instead of the springs shown. in the above described embodiment, an

axial pressure may, for; instance, be obtained from a torpedo chamber-under pressure, for; instance an oil chamber or the" like.v If, desired, a pressure may be setup in chamber 14 itself which pressure atthe same time axially presses t packing i s$. .ee er-,

The, arrangement for automatically equalizing the pressure} may, for instance, consist of a membrane orsome similar device instead ofv the; i .6- Y When: a n s eni sed; he piston spring only serves to equalize the friction of the piston in the cylinder.

What I claim is:

1. In an under-water device of the class described, walls forming a machinery compartment, walls forming an oil reservoir, a cylindrical member extending from said machinery compartment'through said reservoir, a rotatable shaft extending from within said compartment through said cylindrical member, said cylindrical member being formed with an opening therethrough 'Iinto said reservoir, and packing means for substantially preventing passage of fluid be- "tween' said. shaft and said cylindrical member,

said mean QQmprising 'a plurality of resilient rings slidably engaging said shaft, a plurality of resilient rings arranged alternately with respect to the first mentioned rings and slidably engaging said cylindrical member, the rings being arranged in two groups one on either side of, said opening and spring means between the two roup for pressi th radial. faces of the rings together.

2. In an under-water device ofv the class described, walls forminga, machinery compartment, walls forming an oil reservoir, a cylindrical member extending from, said machinery compartment through said reservoir, a rotatable shaft extending from, within said, compartment through, said cylindrical member, said cylindrical member bein formed with an opening therethrough into said reservoir, and packing means for substantially preventing passage of fluid between said shaft and said cylindrical member, said means comprising a. plurality of resilient rings slidably' engaging said, shaft, a. plurality of resilient ringsarranged alternately with respect. tothe first, mentioned rings. and slidably engagingsaid cylindrical. member, the rings being; arranged in, two groups one on either side of said opening and spring means between. the two groups for pressing the radial faceszof the rings together, said; reservoir extending an appreciable distance below said: cylindrical member and providing a, space wherein water leakingpast, said packing meansandthrough said opening may accumulate.

3. In an under-water device of the class .described, wallsforming a machinery compartment, walls forming an oil reservoir, a cylindrical member extending fromfsaid machinery compartmentthrough said. reservoir, a rotatable shaft extending from; within said. compartment throughsaid cylindrical member, said cylindricalmember being formed withan. opening therethrough. into said reservoir; packing. means for substantially preventingpassage of fluidbetween said shaft and; said, Cylindrical member, said means comprisin a/ pluralitygof resilient. rings slidably engaging said. shaft, a. plurality of resilient, rings arranged alternately. with respect tothe first, mentioned: rings and slidably engaging said; cylindrical member, theringsbeing arranged; in two groupsoneoneither side of said opening and spring means between the two groups for pressing the radial faces of the rings together, saidreservoir extending an appreciable distancebelow said-. cylindrical member, and means for communicating pressure. from the, surrounding: water to the, lower part of said reservoir.-. r 41.,In; an under-waterdevice of'the class described, walls-forming: a: machinery compartment. walls forming; an oil" reservoir, a cylindri calzmember extending: from; said: machinery comthrough said cylindrical member, said cylindrical member being formed with an opening therethrough into said reservoir, packing means for substantially preventing passage of fluid between said shaft andsaid cylindrical member, said means comprising a plurality of resilient rings slidably engaging said shaft, a plurality of resilient rings arranged alternately with respect to the first mentioned rings and slidably engaging said cylindrical member, the rings being arranged in two groups one on either side of 'said opening and spring means between the two groups for pressing the radial faces of the rings the surrounding water, and a piston reciprocably mounted in said cylinder.

5.'In an under-water device of the class described, walls forming a machinery compartment, walls forming an oil reservoir, a-. cylindrical member extending from said machinery compartment through said reservoir, a rotatable shaft extending from within said compartment through said cylindrical member, said cylindrical member being formed with an opening therethrough into said reservoir, and packing means for substantially preventing passage of fluid between said shaft and said cylindrical member, said means comprising a plurality of resilient rings slidably engaging said shaft, a plurality of resilient rings arranged alternately with respect to the first mentioned rings and slidably engaging said, cylindrical member, the rings being arranged in two groups one on either side of said opening and means for pressing the radial faces of the rings together.

RICHARD NESSON.