US2499784A - Variable capacity lubricating pump - Google Patents

Description

Patented-Mai'.` "7, 1950 I VARIABLE-CAPACITY LUBRICATING PUMP Eugen' Schmidt, Winter-thur, Switzerland,` assignor to Sulzer Freres, Societe Anonyme, Winte'thur, Switzerland Application September 20, 1945, Serial No. 617.647 In Switzerland November 16, 1943 Section 1, Public Law 690, August 8, 1946 e Patent expires November 16, 1963 3 Claims. l

The invention relates to a lubricating apparatus and its purpose is to reduce the width of the pump set and to simplify manufacture. It consists in that a pump set interchangeable as a whole is provided at least with one feed pump and one high-pressure l'ubricating pump which are connected by an overflow passage in which is provided an adjustable member for measuring the quantity of lubricating medium, the bores for the pistons, their guide means and the overflow passage being arranged in the same plane. It is preferable for the cylinder of the highpressure pump to be inserted in the pump set so as to be individually' interchangeable.

One embodiment of the invention is shown diagrammatically in the drawing.

The figure shows in cross-sectional elevation a lubricating apparatus with the container I in which are inserted a number of pump sets 2 which can be interchanged as a whole and whose joints with the container are oil-tight. All the pump sets are driven by the driving shaft 3, a crank 4 being provided for each pump set 2. The shaft 3 is driven in a known manner and at constant speed by the engine to be lubricated, or if the drive is taken from a reciprocatng part the shaft 3 is equipped with a ratchet drive. The lubricating oil is introduced into the container l through the filling opening 5 with a filter 6. Each pump set 2 has at least one feed pump and one high-pressure lubricating pump in the casing 3 which is attached to the container l by means of bolts 9. The feed pump has a piston o in the bore ll, and this controls the suction passage !2. Beside the feed pump o, Il is the bore l4 for the guide bushing !5 in the drive for the high-pressure piston l6, which works in the cylinder ll of the high-pressure pump arranged in the casing 8 so as to be interchangeable. The guide bushing !5 has an open-ended'scotch yoke surrounding the crankpin 4, and to this yoke the piston o of the feed pump is also attached. The yoke lB is open at one side in order to allow the set 2 to be removed without dismantling, the shaft 3.

The feed pump o, ll is connected to the highpressure pump !6, ll through a passage consisting of the delivery bore |3 connecting up to the bore ll (the two parts of the bore !3 being connected by the recess l9 in the bushing !5) of the outlet with the non-return valve 2l and the discharge 22, of the chamber 23 with the sight glass 24, and finally of the suction passage 25 of the high-pressure pump !6, ll. The bores for the pistons n and !6. the bushins guide I! and the stroke.

passage !3, |9--25, are arranged in the same plane.

In the upper part of the delivery bore l3 is provided the metering piston 26 which is pressed down by* means oflthe spring 21 as a piston opposed to the feed piston o. The piston 26 is provided with a bore 728 which communicates through the transverseports 29 with the return passage 30 in the casing 8.

The high pressure cylinder I'I is equipped with two delivery valves 3| and 32 which communicate with the pipe 33 for the lubricating medium. A knurled knob 34 is provided for adjusting the quantity of lubricating medium, and the cam 35 of this knob cooperates with the flange 36 of the metering piston 26, the position of the knob 34 being indicated by means of a. pointer 31.

The method of working is the following:

i Starting from the positionshown, when the shaft 3 turns in the direction of the arrow 33, the pump pistons o and |6 perform a suction The feed piston n draws the lubricating oil through the passage |2, or this oil fiows to the piston, so that the swept space of the piston n and the bore |3 are filled with oil. During the delivery stroke, after the passage |2 has been closed, the piston !0 forces a, definite quantity into the delivery bore !3. If the metering piston 26 is so set with the knob 34 that the return passage 30 is just covered, the piston 26 is raised until the outlet 20 is uncovered and the oil delivered by the piston ID is forced'through the non-return valve 2l and the discharge 22 into the chamber 23, thus fiowing into the suction passage 25 and arriving in the swept space of the piston l6 when the latter is raised.

The drawing shows piston 26 in the idling position, at which position all the oil delivered by the feed pump returns through passage 28 and openings 29 and 39 to the container. For delivering oil the piston 26 is to be raised and so set by turning the knob 34 that the openings 29 do not coincide with the passage 30. The higher the piston 26 is raised by the cam 35, i. e. the smaller the stroke of the piston 26 up to the uncovering of the discharge 20, the greater is the quantity of lubricating oil supplied tothe highpressure cylinder ll. If on the other hand the piston 26 is so far down that the ports 29 are adjacent to the passage 30, but do not uncover it, the smallest quantity is supplied to the highpressure pump I 6,' ll, while in the lowest position of the piston 26 when the ports 29 coincide with the passage 30 (as illustrated) the quantity of oil supplied is returned through the return passage 99 into the container I and the high-pressure pump II, I'l receives no lubricating medium.

During the delivery stroke the high-pressure piston !9 delivers the quantity supplied, after the closing of the suction passage' 25. through the passages sia, :Za and the delivery valves 3I, 32

` into the pipe 33 and thus to the subsequent lubricating point. i

The counter-pressure composed of the pipe resistance and the pressure at the end of the pipe, for instance the compressor pressure, determines the pressure of the high-pressure pump. whose piston s remains oii-tight against a pressure of more than 1000 atm. abs. The high-pressure pump cylinder l'l rests against the stop 39 and is fixed in the casing 8 by means of the nut 49. The

. guide bus'hing has at its lower end an open connection to the container I through the passage ll In the casing 8 of a set 2 two or more feed pumps lfl, H and an equal number of high-pressure pumps I 6, I 'I might also be arranged, so that a reduction of the distance between the pumps of a set 2 and thus an increase in the total number of pumps is possible without a change in the length of the apparatus.

I claim:

.1. In a reciprocating pump assembly of the v type including a body member, a feed pump cylinder in said body member, a pressure delivery g pump cylinder in said body member, a feed pump piston fitted in said feed pump cylinder, a pressure delivery pump piston fltted -in said pressure delivery pump cylinder, intake openingsin said body member leading to said cylinders, discharge openings in said body member leading from said cylinders, passage means interconnecting' the discharge opening from said feed pump cylinder and the intake opening to said pressure delivery pump cylinder, and a spring loaded metering piston fitted in said passage means and preventing flow therthrough until moved through a predeter-- mined stroke against its spring loading, the improvement which -comprises providing a recess in .the pre'ssure face of said metering piston, apassage connecting said recess to the outside of saidfmetering piston behind said face, a vent `-lea'ding outside said body member arrang'ed to connect with' said passage at the extreme end position of said metering piston under influence of it'sspring loading and means for adjusting th end position 'of said metering piston.

v '4 2.'In`the improved assembly of claim 1 the 'further improvement which comprises providing as the means for adjusting the end position of the meter-ing piston a flange on said metering piston and a helical cam engaging said flange.

3. In a reciprocating pump assembly ot the type including a body member, a feed pump cylinder in said body member. a pressure delivery pump cylinder in said body member. a feed pump piston fitted in said feed pump cylinder, a pressure delivery pump piston fltted in saidpressure delivery pump cylinder, intake openings in said body member leading to said cylinders, discharge openings in said body member leading from' said cylinders, passage means interconnecting the discharge openings from said feed pump cylindeand the intake opening to said pressure delivery pump cylinder, and a spring loaded metering piston fitted in said'passage means and preventing flow therethrough until moved through a predetermined stroke against its spring loading, the improvement which comprises arranging said pressure delivery pump cylinder to intersect said passage means and providing a guide bushing to carry said pressure delivery pump piston, said guide bushing having an exterior annular groove which cooper-ates with the walls of said pressure delivery pump cylinder to form a part of said passage means.

' EUGEN SCHMmT;

REFERENCES CI'I'ED The following references are of record in the file of this patent:

UNITED STATES PATENTS 377335 Great Britain' July 28, 1932

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