US1270182A - Force-feed lubricating system. - Google Patents

Description

R. L. Mcmmsu. FORCE mu LUBRICATING SYSTEM,

APPLICATION FILED JAN 219l3.

1,270, 182. Patented June 18, 1918.

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J, W 53 44 i mam mlaumwaa UNITED STATES PATENT OFFICE.

ROBERT L. MCINTOSH, OF CHICAGO, ILLINOIS. ASSIGNOR TO MCCORID AND COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

FORCE-FEED LUBRICAT ING SYSTEM.

Specification of Letters Patent.

Patented June 18, 1918.

Application filed January 2, 1913. Serial No. 739,608.

To all when it may concern.

Be, it known that 1, Roman L. Mtrlx'roslr, a citizen of the United btates, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Force-Feed Lubriating Systems; and I do hereby declare the following tube a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to improve the construction and action of force teed lubri ating systems. and is particularly direeled to the improvement of that type of forc l'eed lubricating apparatus wherein the oil is delivered under pressure, and against a resistin pre sure. through a socalletl terminal c lttfli valve. More especiall v, the invention i directed toan improved relative arrangement of the said terminal check valve in respect to the pump or oil jl orcinp device ofthe lubricating system.

Generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claim.

Terminal check valves of force feed lubricating systems are located in the delivery ends of the oil deliver) pipes or conduits, and their function is to retain these oil pipes full of oil, at all times and at nearly eon staut pressure. The terminal check valve in common use comprisesa weight ed check needle valve which is a rrangetl to open undera pressure which is very much has than the normal pressure which is maintained in the oil delivery pipe in the feeding action and which is also very much less than the maximum pressure in the chamber which receives oil from the lubricating apparatus.

In these force feed lubricating systems, it

is of the greatest importance to keep the oil delivery pipes, at all times, free from air and vapor, and to keep such pipes always completely tilled with a body of oil.

.As a concrete illustration, the following statements may he made:

In common locomotive practice. a boiler pressure of .200 pounds per square inch is maintained, and in the force fer-d lnhricat ing systems usually employed. an old type of needle point gravity seated terminal check valves are employed. The steam has free access into the valve chamber and when the lubricating system is pumping against a steam pressure, the valve chamber is in commnnication with this pressure, and the steam pressure is exerted on the top of the weight, and on the bottom of the weight with the exception of the area contact of the needle seat. The total downward pressure on the seat is equal to the weight plus the steam, pressure times the to) area of the weight, while the total upwar pressure equals the steam pressure times the bottom area of the weight; with the area of the contact of the seat taken out.

When such a valve is open to the atmosphere at the outlet and the lubricator is 0perated, the pressure of oil in the oil pipes will he just enough to raise the needle valve. This pressure will be equivalent to the weight of the valve divided by the area of contact of the needle seat. in customary practice this pressure is :25 to (it) pounds. llhen this valve is attached to a steam chest and the lnbrieator is delivering oil against the steam in the steam chest, the pressure of oil in the oil pipes will be equal to the pres sure of steam in the steam hest plus the ordinary pressure required to lift the valve in the first case, so that if the steam pressure in the steam chest is 200 pounds, and the resistance of the valve against-the atmospheric pressure is pounds, the oil pres sure in the pipes will be 260 pounds. If the steam pressure in the steam chest is 100 pounds, the oil pressure in the oil pipes will be 160 pounds. The oil pressure in the oil pipe will always be equal to the steam pressure plus the resistance of the valve.

Assume the ease of a locomotive standing still with the oil pressure in the oil pipes at (30 pounds. When the throttle is suddenly opened, the steam chest pressure is increased from zero to 200 pounds, but no oil will be delivered into the steam chest until the oil pressure in the oil pipe has been built up from (30 to- 260 pounds, and when the throttle is shut oil. oil will continue to flow out of the oil pipe until the oil pressure is reduced to, say (50 pounds, at which point the gravity valve will close and prevent further discharge.

A gravity check valve could be made which would lift-at 220 pounds instead of 60 pounds, and while this valve would lift at a higher pressure tliantlie steam pressure, say 200 pounds, the sudden opening of the throttle wouldadd the steam pressure to the resistance offered by the check valve, and no oil would be delivered into the steam until the oil pressure had reached 420 pounds. The point is that the ordinary gravity valve allows a fluctuation of pressure in the oil pipe exactly equal to the fluctuation in steam pressure against which it is operating, regardless of the. initial pressure which the valve by itself retains in the oil pipe.

M object was to design a valve which won (I maintain a nearly constant oil pipe pressure regardless of the steam pressure or vacuum against which the oil was being delivered, by that means eliminating the fluctuation in oil pipe pressure due to a corresponding fiuctuation in steam pressure, thus insuring a constant and uninterrupted regular feed of oil to the steam chest. In other words, the oil pipe pressure would be 250 pounds regardless of whether the steam pressure was zero or 200 pounds.

In the above figures it is assumed that there is no loss of steam pressure between the steam chest and the inside of the ordinary gravity valve chamber. This, however, is not exactly obtained in practice, and in the case of a 60 pound gravity check valve operating against 300 pounds of steam, the pressure of oil in the oil pipe would fluctuate from 235 to 250 pounds.

Many ad *antages are derived from my improved arrangement above set forth. A

' constant oil pressure in the oil deliyery pipe is maintained regardless of varying pressure in the steam'chest. and against which steam chest pressure the lubricator pump has to work. The advantage of maintaining a constant pressure in the oil pipe or conduit is that it insures a constant feed of oil into the steam chest or pressure chamber, regard less of the pressurcin this chest or chamber. Stated in another way, the tinal desired result is obtained, to-wit, the feed of oil to the steam. chests and cylinders will start when the engine starts and stop when the engine stops, so that there will be no waste of oil, and there will always be a supply of oil when the engine is in action. Another advantage obtained by maintaining this constant pressure in the oil feed pipe, very much above the maximum pressure of the steam chest, is that when the oil pipes are so located that they are subject to the same temperature as the boiler or engine cylinders, the oil in the conduit is at a sufficiently high pressure to more than compensate for the contraction which takes place in the oil in the conduit. The volume of the oil conduit is constant and when a sutiiciently greater volume of oil is forced into the conduit, the pressure in the conduit is raised to a given point. This c x- (3635 amount added should be greater than the, volumetricdecrease which occurs when a volume of oil equal to the volume of the conduit is cooled down to ulll'lOSPllQl'lL temperature from a temperature equal to that of the boiler. The Pressure shown when ad ditional oil is forced into the conduit is a direct indication of the volume of oil added. In other words, no matter what contraction of oil in the conduits due to reduced temperature, may take place, the initial pressure of the oil is sutliciently high so that it is not reduced to zero 'or less by this contraction of volume, and some pressure at least is retained on the oil in the conduit. As long as there is any pressure of oil in the conduit, it will be impossible for any air to be drawn in. The contraction above described, due to temperature reduction, is an action which takes place when the enginc is removed from service and allowed to cool oti'. Maintaining a high pressure in the oil conduit at all times, whether the engine is in service or out of service, prevents the drawing of any air or vapor into the oil pipe or conduit, or syphoning of oil from the receiver to replace the volume reduced by contraction, such as is liable to happen under the old form of force feed lubricator, when the volume contraction in the oil takes place in the said feed pipe to the extent that the volume of oil becomes less than the volume of the discharge pipe or conduit. The disadvantageof the presence of air or vapor in theoil pipe or conduit is that such air or vapor must be worked out of the system before a regular delivery of oil can be maintained, the time required to rid the system of such air or vapor varying with the amount thereof. The length of time required to thus rid the system of such accumulated air or vapor may be so long that serious results may follow on account of the lack of regularity in the delivery ot oil to the parts requiring lubrication.

Another disadvantage is that when any air is drawn into the pipes while the locomotive and the lubricating system are old. the locomotive is again heated up, the oil in the conduits expands and the only cscape for it is out the ordinary gravity check valve, provided that the heat is sutiicient to increase the volume of oil enough to raise its pressure above that required to lift the gravity valve against atmospheric pressure; oil then flows out at a time when no lubrication is required, and that amount of oil is thereby wasted.

My invention applied in the force feed lubricator system of a locomotive is illustratcd in the accompanying drawings whercin like characters indicate like parts throughout the several views.

Referring to the drawings,

Figure 1 is a view in side elevation showing a locomotive partly in diagram. and illustrating my invention incorporated in the force feed lubricating system thereof; and

Fig. 2 is an enlarged vertical section. taken through the terminal Cl1(:'(l( valve on the line .12 1 on Fig. 1.

Of the parts of the locomotive, it. is only desirable for the purposes of this ease to particularly note the boiler 1. the cab 2. the cylinders 3, and the steam chest 4;. ()f the parts of the lubricating system. it is only necessary to note the force teed lubrirator proper (whirh inrludes the pumps). indicated as an entirety by the numeral 5. and one of the oil delivery pipes t' whioh parts may be of the usual or any suitable ronstruetion. in which oil is adapted to be do liver-ed lo the cooperating steam rheet 4 under the required high pressure. The do livery end of the said oil pipe 6 is ronnertrd to a threaded nipple T of a two-part easing 8--9 of the terminal rheek valve. The set:- tion 8 of the said terminal eherlr valve is provided with a depending threaded nipple 10 which is srrewed into the top of the steam (host 4. 'ithin the section of this valve casing is a cylindrical valve seat 11. in which works a piston-like check valve 1.2, which, as shown, is normally pressed downward by a coiled. spring 13 made adjustable by a set screw 1-1. which is screwed into the upper end of the section 5! of the valve ras ingfi An oil conduit 15 extends from the re et-iving end of the nipple T to the bottom of the ('ylindenlike valve seat 11. and another oil delivery conduit to extends f1" Ill one side of the said valve seat ll, to the deli. es'jv end of the nipple 10. In the ronstrurtion illustrated, the valve 12 is provided at its intermediate portion, with an annular oil groove or port 17 which is in constant (01H- muniration with an axial oil conduit 18 that extends from the said port. 17 down ward to the extreme lower end of the said valve.

It will, of rourse, be understood that. the spring 13 must he et under .surh tension that the said valve will be opened, by upward movements. Causing its port 17 to aliue with the receiving end of the. conduit 16. only by a pressure whirh exceeds the normal maximum steam chest pressure. or pressur against which the pmnps ol' the lubrioator must work to raustthe delivery of oil into the said st am rhrst or oil roreivinn chamber.

\Yhrn this is dour. the various de ired. and very murh improved artions above t'ully (lesrribed will. ot roursr. take place.

Obviously. when oil whirh is flll't'ttl into the conduit 15. equals or ext-reds the assumed pressure of 250 pounds per square inch. under whirh the said terminal rhrrk valve is set to open, the port 17 routing into too- In practire. the above described lubri- -ator. with its (her-k *alve set to open onl V under pressure. exceeding that. against which the oil is fed. has been found highly rliit'irut for use in ronnertion with lUtUlllO' tires. but it will be found useful when applied to internal combustion engines, and elsewhere. where oil must be fed against fluctuating pressures. It is also desirable for use even in rtmnertion with ordinary stationary engines. The statements made in this paragraph are especially true in re sport. to a (h-art; valve which discharges at a higher oil pressure than the steam pressure and in which the steam pressure is entirely alaneed. or nearly so, within. the valve. as is the ruse of the piston (heck valve where the steam has across to the annular oil groove on the piston when the piston is in the disrhargr position. so that the upward and downward steam pressure romponents zit-ting on the valve equalize earh other and the steam pressure. therefore. is eliminated from el'l'eeting a. movement of the valve. This is a distinguishing different-e between our valve and a. gravity needle. rhet-k valve made to lift at a higher pressure than the steam, in \vhirh ease the steam pressure would not be eliminated from otter-ting the movement of the valve, but would act against the movement of it. and would add the steam pressure to the resistant-o of the valve itself.

hen the locomotive is standing still and the oil pump is not working. oil is trapped in the oil ronduit between the pump and the piston valve 12. under a predetermined pressure. The chamber in which the piston valve 12 is mounted ail ords an intermediate oil chamber. and the lower end of said valve serves as that portion of the valve meehanism which is exposed to the pressure of the oil in the conduit. The lower end of the valve, or the portion exposed to the pressure of the oil in the conduit. is rut otl from the ovlinder pressure by another portion of the valve merhanism, to wit, the side wall ol the piston valve. The valve therefore. not. affected by the back fluid pressure from the ryliuder.

In this sperltieation and in the claim. the term pressuro is used in a liberal sense to include partial vacuum or a pressure wlnrh is below atmospheric pressure, and which is frequently designated as a negative pressure.

What-I claim is:

The combination with a locomotive, of a lubricating system therefor, comprising an oil pump driven from the runnin arts of said locomotive, oil. delivery con uits leading from said pump, and terminal valve mechanisms each of which has one part for controlling the discharge of oil from its conduit to the eorrespondin cylinder and another part exposed to tile pressure of the oil in the conduit, but cutoff b said firstnoted part, from materially e ective back pressure from the cylinder, and yielding means operative to close said valve mechanism in opposition to a. predetermined oil pressure that at least equals the maximum variable fluid back pressure from the cylinders, but permitting t id valve mechanism to open under an oil pressure that exceeds said maximum predetermined pressure.

In testimon whereof I ailix my signature in presence 0' two witnesses.

ROBERT 'L. MoINTO-SH.

Witnesses:

DONALD D. MILLIKIN, C. W. RUDOLPH.

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