US1385005A - Reciprocating pump and the like - Google Patents

Description

K. O. KELLER.

RECIPROCATING PUMP AND THE LIKE.

APPLICATION FILED IAN. 6. 1921.

'L BS. Patnted. July 119, i921.

11], III! y aaeaoea.

OFFICE.

EARL @TTU KELLER, 0F SUND r ROBERT PILE DOXFORD;

SUNDERLND, DURHAM, ENGLND.-

\ Y l ENGLAND, SSI\G1\TOR 0F ONE-HALF T0 REGIPROGTHIG PUMP .AND THE LME.

Specification of Letters Patent.

rateatea ,nay ia, raar? appncatmn mea January e, mi. serial no. 435,354.

To all whom t may concern.'

. Be it knownthat I, `Kann O'rro KELLER, citizen 'of the Swiss Confederation, of'lPallion Yard, Sunderland', in the county of Durham, England, have' invented certain new and useful Improvementsin Reciprocating Pumps and the like,- of which the following' is a. specification.v y

rlhis invention is for improvements in orvrelatin to reciprocating pumps and-.the like, and llas for its object to provide an improved construction of driving-mechanism foroperating the ram or plunger in a reciprocating pump. lThe invention is particularly applicable to pumps which are required to work under a high pressure, such for example, as the fuel pumps of internal combustion engines.

'@n'e of the difficulties with reciprocating pumps is the prevention of leakage past the ram, due either to want of alinement of the ram in its cylinder, or to `wear taking place. When working against low prenssures, say up to 1,000 lbs., per lsquareinch, this diculty can be obviated by the usey of` packing-glands, as they can be rendered tight without causing too much friction, and the particles which are rubbed off the packing material and find their way into the vfuel-oil do not seriously interfere withr the spraying devices used in engines working with these low fuel pressures. however, is di'erent when pressure of 10,000 lbs. per square inch or more are desirable. A gland `on the ram is not practicable owing to the friction resulting from making the gland tight against the high pressure, which friction causes heating of the ram. Moreover, the particles which become detached from the packing material seriously obstruct the fine passages ofthe fuel-spraying device, such for example, as is described in our patent specification No. 394682 filed 8th July, 1920'.

'We have found it practicable to machine a ram and its cylinder or sleeve so accurately o1l under pressure up,

that the leakage of" to 12,000 lbs.l per square inch is negligible 4under a static test, and the object of this invention is to provide driving mechanism Dr coaxial with the axis The case,

'for aram which shall eliminate as vfar as posslble, by elimination of side thrust on the ram, all 'wear which would lead to leakage. 7

We have heretoforeused nectlon for a ramor a member which slidesl a driving conplunger comprising 1n aguide parallel of the .ram and engages 1t bya face which is perpendicular to the direction in'which they' move; this face permits relative sliding movement of the driving member and the ram in the. 'sald plane perpendicular to the direction 1n whlch they reciprocate, the object of this arrangement being to insure that any displacement 'of the driving member from its orlginal coaxial position shall not cause the ram to be tilted out sition.

According tothis invention, in a reciprocating pump comprising a "driving member which exerts thrust that may be other than coaxial with the' ram ofthe pump, .anda cross-head joined to the pump-.rain by ar sliding-joint between that cross-head and ram in 'a plane perpendicular to the direction in which the ram'reciprocates, there is employed aiirst cross-head whichY is connected to the cross-head of the ram by a `thrust-connection interposed' between'- the two cross-heads and either connected to each of. its original poe of the cross-heads at its ends, for the purlFig. 3 shows almodiied construction.

f eo

Like reference characters indicate like parts throughout* the drawings. 4 Referring tollig, 1, a pump comprises a I pump, which may ram 10 reciprocating in a sleeve 11, these two parts being machined initially With such accuracy that the leaka e at the desired working pressures is negligi le. The pump chamber is indicated at 12.

The primary driving member of this be of .any desired kind, is usually one which introduces 'a lateral thrust as well as the axial thrust which is required on the ram. As illustrated,'the primary driving member is a connectingrod 13 operated by a crank or eccentric 14. The other end 15 of this connecting-rod is mounted in a cross-head 16 which is free to slide in a guide 17, and this guide is originally made with its longitudinal axis parallel with and preferably coaxial with the axis of the ram 10. The cross-head 16 absorbs all the lateral thrust introduced by the Obliquity of the driving member 18, and it transmits only a thrust which is initially coaxial with the ram. But when wear of the guide 17 and cross-head 16 takes place, the line of movement of the cross-head is no lon er coaxial with the ram, and the transmitted thrust may be not coaxial with the ram. There is, therefore, provided a second cross-head 18 which slides in a guide 19, this guide being (like the guide 17) initially machined with its axis parallel with, and preferably coaxial with the axis of the rain.

The two cross-heads are connected by a thrust-member 20 which is connected to either of them or both of them by a joint which permits displacement of the crosshead relatively to the thrust-member in a direction at right-angles to their line of movement. Such a joint is illustrated in Fig. 2 in which the cross-head 16 is provided at its end with a flat face 21 which is accurately perpendicular to the longitudinal axis of the cross-head. rPhe thrust-member 20 is formed with a corresponding fiat face 22 which bearsy on the face 21 and is perpendicular to the axis of the thrust-member. The two arts are held in contactV by ai nutlike memlger 23 screwed on to the cross-head 16 and engaging by an inwardlydirected flange 24 a shoulder on the member 20 which faces away from the cross-head. The ilange 24 is so 'proportioned as to allow a certain amount of lateral movement of the crosshead 16 and nut 23 relatively to the thrustmember 20. With this construction, if the cross-head 16, due to wear of its guides 17 moves along a line displaced laterally from the original lineof movement, no tilt is imparted to the member 20 because the face 21 slides freely across the coperatin face 22 of the thrust-member 20 so that t e latter maintains its original axial position.

The only possibility of a non-axial thrust being imparted to the thrust-member 20 arises if the guide 17 is worn to a curve,

so that the end face 21 of the cross-head becomes tilted and does not lie flat against the end face 22 of the thrust-member 20. In this case the thrust might be applied to the member 20 to one side of its longitudinal axis.

It will beV appreciated that any lateral thrust thus introduced byeccentricity or Obliquity of the thrust transmitted from the cross-head 16 can only be small, and it is absorbed by the second cross-head 18. Any wear caused by this side-thrust willl be very small compared with the wear of the crosshead 16 and guide 17. The rain 10 is connected to the cross-head 18 by a. joint similar to that illustrated in Fig. 2, so that even the slight wear and lack of alinement which may in time arise on the cross-head 18 is not imparted to the ram 10, and the latter maintains its initial accurate fit and `oilti htness in the sleeve 11.

ile the construction illustrated in Fig. 1 is the preferred one, similar advantages may be obtained by a construction such as is illustrated in Fig. 3, wherein the thrustmember 20 is connected to the cross-heads 16 and 18 respectively by pin-joints 25 which are arranged with their axes transverse to the direction in which the reciprocation-of the partstakes place. With this construction the displacement from its initial alinement will impart ,a slight tilt to the thrust-member 20; the thrust imparted to the member 18 will thereby be very slightly oblique, andthelateral component will be absorbed by the crosshead 18 causing wear thereof which is, as before, very small compared with the wear of the cross-head 16. The joint between the cross-head 18 and the ram 10 is of the same type as in Fig. 1 so that even the small amount of wear between the cross-head 18 and its guide 19 does not cause any appreciable lateral thrust on the ram 10.

It is to be understood that this Vinvention is not limited to the particular driving mechanism comprisin an eccentric and connecting-rodV illustrate in Figs. 1 and 3, but that the hereinbefore-described arrangement of two cross-heads and guides may beinterposed between any form of driving member and the ram of the pump. y

What I claim as m invention and desire to secure by Letters atent is 1. In a machine of the character described, the combination of an oscillatingl and reciprocating driving member, aram, a plurality of cross-heads between said driving member and said ram and connecting the same so as to permit Vrelative adjusting movement between any connected pair of said elements in a direction transversely of the line of reci rocation vof said ram, substantially asv escribed.

2. In a machine of the character described,

fof the cross-head 16 v aseaeoe y the combination of an oscillating and reeipb justing movement between them in a direc 10 roeating driving member, a ram, a plurality tion transversely of their line of reciprocai1 of cross-heads between said driving member tion, substantially as described.

ano said rlam,d and eans comacting one of In testimony whereof I ax my signataireo sai crossea stot eram, sai means ein 1 adjustably movable relatively to the raiigi KARLOTTO KELLER transversely of the line of reeiprocation of YVlitnesses: f

said ram, and means connecting said cross- WILLIAM RAwmNGs,

beads together and permitting relative ad- WILLIAM HAMILTON Purline,

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