US1523707A - Pump - Google Patents

Description

c. E. NAGEL PUMP Filed: Ma :51, 1925 2 Sheets-Sheet 1 VENTOR CA 5 NAGEL.

ATTORNE s.

flan. 20. 1925; I 1,523,707

c. E. NAGEL PUMP File ay 31, 1925 2 Sheets-Sheet 2 INVENTOR CARL 5. NA GEL.

ATTORNE s.

such a spring UNITED STATES PATIENT OFFICE.

CARI/E. NAGEL. or OAKLAND, camromvm.

rnmr.

Application filed May 31,

-To all whom it may concern:

Be it known that I, CARL E. NAGEL, a citizen of the United States, residing at Oakland, county of Alameda, and State of California, have invented new and useful Improvements in lowing is a specification.

This invention relates to a pump and especially to that type which depends upon the viscosity of an oil or other fluid film for its operation.

Fuel pumps at present employed for the purpose of supplyingv fuel oil under high pressure to the fuel. valve ornozzle of a Diesel engine, especially such engines as employ solid or mechanical injection are usually of the variable displacement type. I pumps require expensive workmanship on the fitting of the plungers, valves, etc., as the pressures-employed often exceed 4,000 pounds per square inch.[

In. the usual fuel system the pump de livery is not exactly timed to coincide with the opening of the-fuel valves and various storage systems are, therefore, required as, for instance, an air dome in which the en- T trapped air is highly compressed when thefuel pump delivers its charge; this air being permitted to expand and force thefuel out of the line when the fuel valve lifts. Devices arealso necessary in fuel systems of this character, such as spring loaded-plungers which operate in a cylinder to uncover a port in the side of the cylinder, thereby by-passing any "excess fuel delivered by the pump and returning it 'tothe supply line;

' ing the building up of excess or dangerous l '1 and links andfthe-lost motion due to wear.

pressures.

The governors employed on Diesel'engines are generally of the centrifugal type and are usually connected with the part to be operated by means of a number of links, levers,

etc. Such governors are generally sluggish in operation, and permit considerable speed. variations before they operate; this being due to the friction encountered in the levers Theobject of the presentinvention is to generally-improve and simplify the construction an o eration of pumps of the rotating t pe w ich-depend upon the viscosity of like fluid for its operation; to character which will an 0i or provide a pump of this have a sufiicient capacity to serve as a Pump, of which the fol- Such loaded plunger also preventa fuel 1923. Serial No. 642,412.

valves, etc. Other objects will hereinafter appear.

One form which my invention may assume is exemplified in the following description and illustrated in the accompanying drawings, in Which- Y section of the pump.

Fig. 2 is a side elevation partly broken away, said figure also showing one-half of the pump cover removed. v

Fig. 3 is an enlarged detail plan view. of one of the shoes.

' Fig. 4 is a side elevation'of thesame.

Referring to the drawings in detail, and paticularly to Figs. 1 and 2,'A'indicates in general a pump casing which in this instance is divided into two sections such as lndlcated at 2 and 3; these sections being secured together'by means of bolts and nuts as indicated at 4 and, 5. Formed between the two pump casing sections indicated at 2 and 3 is a; central chamber 6, and mounted in said chamber is a disk or rotor 7 which is secured on a driving shaft 8, the shaft 8 being journaled as at 9 in a bearing member 10 forming a portion of the casing section 3. The central chamber 6 is circular in formation and its peripheral portion is enlarged on each side of the rotor 7 to form a pair of communicating annular chambers 11 and 12. Disposed in the chamber 11 are a plurality of shoes 13 and similarly disposed in the chamber 12 are .a plurality of shoes 14; these shoes being interspaced as shown at 15, in Fig. 2, and being held in what may be termed frictional engagement with. the opposite faces of the rotor 7 by means of pins 16- These; pins are supported by the re- F 'g. 1 is a central, vertical, longitudinal 70 means of a coupling 26. 10,

pin is connected with a discharge pipe 23 by means of suitable couplings such as indi cated at 24; the pipes 23 being all connected with a common manifold not here shown.

The fuel oil to be pumped and discharged under pressure is delivered from a suitable source through a pipe 25, which is connected with the center portion of the casing 2 by The oil thus entered is discharged by centrifugal force against the shoes 13 and 14, which, due to the viscosity and the adhesive quality of the oil, is forced between the shoes 13 and 14 and the rotor in the form of a film, a portion of this film being continuously discharged through ports 27 formed in the respective shoes which align with the ball and socket bearings 21 and the discharge passages 22 and pipes 23.

It should be remembered that the pump forming the subject matter of the present application depends upon the viscosity of an oil or like fluid film for its operations; therefore, to clearly explain the principle of operation the following facts might be stated:

When one flat surface, for instance, the inner face of the shoe 13 illustrated in Fig. 4, is-pressed directly against another flat surface, for instance, the side of the rotor 7, (see the same figure), and if it is assumed that the side of the rotor or flat surface is covered with oil, the oil film between thetwo surfaces will be squeezed out. On the other hand, if movement is imparted to one flat surface or, inother words, the rotor, the two faces when free to move with relation to each other will assume an inclined position as illustrated in Fig. 4 and thereby become separated by a wedge-shaped film of oil. The film thickness increases with the viscosity of the oil and the speed of the rotor, but experience has shown that no low speed or high speed limits can be reached. Furthermore, that the pressure on the film between the shoe and the rotor varies from nothing or zero at the edges of the shoes and reaches a maximum about centrally of the shoe or at a point in alignment with the discharge port 27. If it is desired to discharge oil under high pressure, it is only necessary to increase the speed. Assuming that the viscosity of the oil remains constant and if it is desired to discharge the oil under lower pressure, it is only necessary to lower the speed.

T 0 further illustrate the operation we will first consider the action when no oil is drawn off through the ports 27 and when the rotor is turning very slowly. In this case only a small amount of oil is carried under the shoes by the rotor and very little pressure is generated under the shoes, it being furthermore found that there is only a slight tendency to force the oil out at the side edges of the shoe. If this is the case the film of oil formed will, practically speaking, assume a uniform thickness from end to end of the shoe.

.Ve will next consider an increase in speed. If this is the case the amount of oil carried by cohesion becomes greater and the leading edge of the shoe is thereby slightly lifted and a wedge shaped film is formed as shown in Fig. 4. Tilting of the shoe with relation to it's stationary support causes pressure to be generated in the oil film and this pressure forces apart of the oil out under the side edges of the shoes and if we assume that the speed and pressure generated-are such that one-fourth of the oil entering under the leading edge is squeezed out at the sides, then the thickness of the film of oil under the trailing edge will be three-quarters that of the film thickness under the entering edge.

For each speed of rotation there is a certain inclination on the face of the shoe which differs from that of any other speed, and where the shoes aremot free to tilt on their ball and socket bearings, there would be only one speed at which high pressure could be obtained for at that speed only would the relative thickness of the film of oil at the entering and trailing ends be properly. proportioned.

\Ve will next consider the action when the rotor is turning at a fixed speed and oil is discharged through the ports 27; that is, we

will assume that the faces of the'shoes have assumed a position such as shown in Fig. 4, this figure showing an exaggerated wedge of oil. \Yhen a small amount of oil is allowed to pass through the port 27 in the center of the shoe. this escape or discharge reduces the amount of oil escaping at the trailing end and as this is the case the trailing end of the shoe drops, thus raising the leading dege and thereby admitting an increased amount of oil under the shoe.

lVith the operation continued a condition of equilibrium will be set up and the same oil pressure will be maintained when oil is drawn off through the central port 27 as exists for the same speed of rotation with no oil passing out. Again, if the shoes were fixed or caused to assume a predetermined inclined or angular position, and oil is allowed to pass out, the pressure would drop, as there would not be enough oil left under the shoe to maintain the pressure, but when the shoeis permitted to automatically tilt as here illustrated, the pressure will be constantly maintained as the amountof oil escaping through the port 27 is compensated for by automatically increasing the inclined position of the shoes. It is for this reason that the pump is particularly adapted to furnish fuel oil to a Diesel engine employing solid or mechanical injection. By employing a multiplicity of shoes with the disi charge pipes'23 connected to themego'z reel pipe which leads to the fuel valves, and with the pump driven by the engine, it can beseen that, when the fuel valves are operated in'succession by the usual mechanism, fuel will be delivered from the pump direct to the fuel valves and the full pressure will be maintained as long as the fuel valve is open; that is, the fuel pressure will not drop during the opening period as is'thecase when the pressure is furnished by the' "expansion of the air n the air dome or some similar arrangement as previously referred \Vhen the fuel valves {are closed the shoes automatically adjust --themselves to this condition and the oilpressure in the will thus remain the same as piping system when the pump is. discharging oil, thus eliminating the necessity of safety or bypass valves and furthermore preventing building up of excessive or dangerouspressures in the piping system.- [While ajpressure of 4,000 pounds'is readily obtained; it should be understood that thepressure may be increased or decreased eithe'r'by-adjust;

ing the position of the pins. so as tobring the-shoes into closer contact with thefsides of the rotor or by increasingthe speed of the rotor or. decreasing the sameas the Pressures approxlmatmg case. may be.

as the experience and judgment of the manufacturer may dicate or various uses may demand.

Having thus described my invention, what I claim and desire to secure by- Letters Patent is 1. In a pump of the character described,

a rotor, means for applying a film of oil to the surface thereof, means for placing said film under pressure, means optionally per-' mitting a portion of the oil in the film to continuously or intermittently discharge under pressure, and means for automatically maintaining a predetermined and constant .pressurewhether the discharge be continuous or intermittent.

2.- In a pump of the character described,

a rotor, means for applying a film of oil to the surface thereof, means for placing said film under pressure-,-f lmea ns optionally permitting a portion of the oil in the film to continuously or intermittently discharge un- ,der pressure, means for automatically main 14,000 pounds per square inch can be ob} tained, but such pressures are-not neces.

- siredl Experience. has shown "that the thicker films allow greater proportions of Y oilto be withdrawn before the trailing-edge pressure is therefore encountered. The onlyv change in-pressure will be caused'byvariaof .the shoe is in dangerofcqntacting with the rotor. It should be understood-that the viscosity of the oil, practicallyspeaking,

remains constant and that thespeed of therotor varies. with engine speed'ja's it ,isdriven thereby. As this is the casefit is only neces-' sary to adjust the individnal'fshoes'when thev sary and the supporting pins lfi' are there fore adjusted to produce a film which will give the quantity of oil. and pressure depump is installed as a specific or prede termined maintaine properly adjusted, .it can be seen'that a" pre-- determined. pressure will be maintained; this being true whether the fuel valves are open or closed. If the fuel valves are open and the'fuel oil is discharging,theq tilt of are closed, the tilt decreases and nolrise in tion in speed of the rotor.

I wish it understood that while certain features of the present structure are more pressure is usually employed and- When the shoes have been the shoes will increase, and if the fuel valves f -s1 pp'ort,' for each shoe permittin taining a predetermined and constantpresa sure whetherthe discharge be continuous or intermittent, and'means for increasing or decreasing-tthe pressure by increasing or decreasing the speed of the rotor.

3.. Ina pump of' the-character described,

a-rotor, means for. applyin a film of oil to the surface ofthe rotor, a p urality. of shoes positioned adjacent the surface of the rotor and adaptedto form a plurality of wedge shaped oil films, and also adapted to maintain said films under pressure, and means for increasing or. decreasing the pressure of of the rotor and to form a plurality of wedge shaped oil films, and an adjustable an m-. crease ,or decrease in the spacing between the shoes and. the rotor.

5. In a pump of the'character described,

.a casing-,j chamber formed ,therein, a disk shaped rotor disposed in said chamber, means for'rotatingthe rotor, a plurality of shoes disposed in the chamber adjacent one or less specifically illustrated, thatjvarious changes in form and proportion I may be resorted to within the scope of the appended claims. I Also, that the material's and. finish of the several parts employed may. be such face of the rotor, 'means for maintaining "a predetermined spacing between each shoe andfthe rotor, and means permitting a slight tilting movement of each shoe'with relation to the rotor.

6. In a pump of the character described,

a' casing,a chamber formed therein, a disk shaped rotor 'dlSPOSGd 1nv said chamber.

means for rotating the rotor, a plurality of shoes disposed in the chamber adjacent one face of the rotor, a ball and socket bearing forming a support for each shoe, and means permitting adjustment of each ball and socket bearing to increase or decrease the spacing between the shoes and the rotor. said ball and socket bearings also permitting a tilting movement of each shoe with relation to the rotor.

7. In a pump of the character described, a casing, a chamber formed therein, a disk shaped rotor disposed in said chamber, means for rotating the rotor, a plurality of shoes disposed in the chamber adjacent one face of the rotor, a ball and socket bearingforming a support for each shoe, means permitting adjustment of each hall and socket bearing to increase or decrease-the spacing between the shoes and the rotor, said ball and socket bearings also permitting a tilting movement of each shoe with relation to the rotor, a discharge port formed ineach ball and socket bearing, and a discharge port formed in each shoe in alignment therewith.

8. A pump of the character described comprising a casing having a chamber formed therein, a shaft extending through one side of the casing and journaled therein, a disk secured on said shaft, bearing pins extending through each side of the casing and entering the chamber, said pins being adjustable on the longitudinal ,axis and each pin having a central discharge port formed therein and extending longitudinally therethrough, a plurality of shoes disposed in the chamber adjacent the opposite faces of the disk, each shoe having a discharge port formed therein, a ball and socket bearing formed between each shoe and pin to permit a slight tilting movement of the shoes with relation to the opposite faces. of the disk, and means for delivering oil to the chamber in the pump casing.

9. In a pump of the character described, a smooth surfaced rotor, a plurality 'of shoes cooperating therewith, and means permitting adjustment'of the shoes to and away from the surface of the rotor.

10. In a pump of 'the character described, a smooth surfaced rotor, a pluralityof shoes cooperating therewith, and means permitting a tilting movement of the shoes with relation to the rotor.

11. In a pump of the character described. a rotor, a plurality of shoes coing a support for each shoe, each shoe having a discharge port formed therein, and a discharge pipe connected with each ball and socket bearing and communicating with the discharge ports in the shoes.

14. In a pump of the character described, a rotor, a plurality of shoes cooperating therewith, a hall and socket bearing forming a support for each shoe, each shoe having a discharge port formed therein, a discharge pipe connected with each ball and socket beariug and communicating with the discharge ports in the shoes, means for delivering oil to a point intern'iediate the shoes and the rotor. and means for adjusting the shoes with relation to the rotor toincrease or decrease the spacing between the shoes and the rotor.

15. In a pump of the character described, a rotor,'mcans for applying a film of oil to the surface of the rotor, a. plurality of shoes pivotally supported adjacent the surface of the rotor and adapted to form a plurality of wedge-shaped oil films, and also adapted to maintain said films under pressure, and means permitting discharge of a portion of the oil in each film through the shoes.

CARL n. Naenn

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