US3069177A - Fuel unit - Google Patents

Description

Dec. 18, 1962 R. w. ERIKSON FUEL UNIT Filed Sept. 30. 1959 2 Sheets-Sheet l Inn L'kson;

INVENTOR.

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FUEL UNIT Filed Sept. 30. 1959 2 Sheets-Sheet 2 1\ s kg N IN V EN TOR.

ioberz, Zfl 521725027 United States Patent Ofifice 3,069,177 Patented Dec. 18, 1962 3,069,177 FUEL UNIT Robert W. Erikson, Rockford, Ill., assignor to Sundstrand Corporation, a corporation of Illinois Filed Sept. 30, 1959, Ser. No. 843,528 1 Claim. (Cl. 277-93) This invention relates to a pump and more particularly to a pump of the gear type.

It is a general object of the present invention to produce a new and improved pump of the character described.

It is a more specific object of the invention to produce a new and improved pump of the gear type which is capable of operating over longer periods without leaks or other difliculties which would necessitate repair or replacement of parts.

It is still another object of the invention to produce a pump of the character described in the preceding paragraph which includes a shaft rotatably mounted in the housing for rotating the gears of the pump and including a new and improved seal between the shaft and the housingto prevent leakage of oil along the shaft and ultimately out of the housing.

Other and further objects and advantages of the present invention will be readily apparent from the following description and drawings, in which:

FIG. 1 is a flow diagram of a pump embodying the present invention;

FIG. 2 is an enlarged detail view of the shaft seal of the present invention;

FIG. 3 is a top plan view of a pump embodying the invention;

FIG. 4 is a longitudinal sectional View taken along line 44 of FIG. 3; and

FIG. 5 is a transverse sectional view taken along the line 55 of FIG. 3.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail one specific embodiment, with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring now to the drawings, there is shown a pump particularly adapted for pumping fuel from a tank or other supply and supplying it under pressure to a burner nozzle. The oil burner pump shown includes a casing provided with a cap 11 at one end thereof secured by bolts as shown to the body 12 of the casing. The cap 11 is hollow to provide a reservoir 13 and in the reservoir there is located a cylindrical screen 14 for preventing solid particles in the oil from entering the pumping mechanism. At the top of the casing there is an inlet port 15 and an alternate inlet port 15a is provided at the bottom of the casing. Either of the inlets may be used depending upon which is more convenient, and the particular installation, and the inlet not in use may be closed by a suitable threaded plug.

Rotatably mounted in the casing 10 is a drive shaft 16, rotation of which serves to rotate a first stage gear type pump 17 and a second stage gear type pump 18, the first stage pump 17 being provided with an internally contained ring gear 19 meshing with an externally contained pinion gear 20 with the gears being faced so as to provide a space therebetween opposite the point of close mesh with said space being occupied by a crescent member 21. The sec 0nd stage pump is provided with similar gears including a ring gear 19a, a pinion 20a, and crescent 21a. The shaft 16 is provided with a shaft seal generally indicated at 22 to prevent leakage along the shaft and the details of this seal will subsequently be described fully.

The first stage pump 17 is provided with an intake 23 2 and a discharge 24 with the discharge being returnable either to the reservoir 13 or to the tank from which the oil is drawn through the medium ofa pipe 25 connecting I the discharge to the reservoir or through a discharge port 26. A threaded plug 27 may be used to determine the final disposition of the discharge of the first stage. When the plug is in the position shown, the discharge of the first stage is through the port 26 to tank, while when the plug 27 is removed and a similar plug is used to block the port 26, discharge is to the reservoir.

The first stage pump 17 acts primarily as a lift pump to bring oil from the tank or other place of storage to the reservoir 13 and its purpose is to maintain the reservoir 13 full of oil. It will be noted that the intake of the first stage pump is located at the top of the reservoir. Hence, it will serve to draw ofi air or foam from the reservoir so that the lower portion thereof is always filled with solid oil. The second stage pump =18 draws its oil from the bottom portion of the reservoir and as it is this oil which is ultimately delivered to the burner nozzle, the advantage of the described locations for the intakes of the first and second stage pumps becomes apparent. Thus, the second stage intake 30 is located as shown in FIG. 1 near the bottom of the reservoir. The second stage pump discharge 31 is directed to a burner shut-off valve 32 which controls a burner port 33 connected to the burner. The valve 32 is similar to the cut-off valve shown in the Erikson Patent No. 2,763,336 and includes an inlet chamber 34 to which the discharge line 31 is connected and a plurality of vertical passages 35 opening at one end to the inlet chamber 34 and at the other end to an outlet chamber 36. Oil under pressure supplied by the second stage pump is directed to-the outlet chamber 36 and when the pressure is sufficient, the valve 37 slides upwardly within the sleeve 37a against the opposition of spring 3811. The sleeve 37a is held in position by a retainer spring 33. The tension of spring 38a acting in opposition to the pressure may be adjusted by the knobs 39 against which one end of the spring bears.

The valve 37 is carried at the lower end of a piston slidable in the sleeve 37a and the piston walls are provided with openings 40 connecting to an annular groove 41 formed at the exterior side walls of the piston and that annular groove may be moved to communicate with the inlet chamber 34 when the piston moves upwardly sufficiently in response to increasing pressure. As the interior 42 of the shut-off valve is connected to drain by means of the pipe 43, movement of the piston upwardly to a point establishing communication between the inlet chamber 34 and the interior of the valve through the medium of the grooves and openings 40, 41 serves to limit the pressure of oil delivered to the burner nozzle. The pressure may be checked from time to time through the medium of gauge port 44 which connects as shown to the second stage discharge line 31.

As indicated earlier, novel shaft seal means are provided for preventing leakage of oil along the shaft 16 from the area of the pumps 17 and 18 and ultimately out of the right-hand end of the casing. Referring now to FIG. 2, it will be seen that the shaft seal 22 includes a floating ring of low friction material such as nylon, having a clearance 51 from the shaft of the order of .005 inch or even greater, and thus is free to adjust its position automatically so that its face 52 can engage the face 53 of the adjacent portion of the housing. A pin 54 extends through the shaft 16 and into suitable slots 54a provided in the ring 50 so as to rotate the same with the shaft. Covering the ring 5%) is a spring supporting cap 55 against which one end of a compression spring 56 bears, the other end of the spring bearing against a corresponding cap 57 covering a leaded bronze ring 58. The bronze ring is provided with a face 59 bearing against a correspending sealing face 60 provided on a ring housing member 61 sealed to the housing 12 by O-ring 64. A second O-ring 65 provides a seal between the shaft and the leaded bronze ring 58 and the ring housing member 61 is maintained within the recess and the housing by removable snap ring 66. A drain line 67 connects the recess housing the sealing ring to the drain line 43 as shown.

As indicated earlier, the ring 50 is floating by virtue of the clearance previously described and thus is more or less self-adjusting to the face of the housing. The O- ring 65 does not supply the sole driving force between the shaft 16 and the rotating bronze seal 58 as a good deal of the driving force is supplied through the medium of the spring 56 which is rotated through its contact with the upper surface of the ring 50 which is, as previously noted, pinned to the drive shaft.

I claim:

A rotating seal of the character described comprising a housing having a hollow therein, a shaft rotatably supported in said housing and extending through the hollow, oppositely facing annular seating areas in the housing and surrounding the shaft at each end of the hollow, a nylon ring encircling but spaced from the shaft loosely to surround the same and having an annular face bearing against one seating area, means providing a driving engagement between said nylon ring and the shaft including a pin extending through said shaft and into a slot provided in said nylon ring to allow said nylon ring to freely and automatically adjust its position in sealing engagement with said one seating area, a second ring having an annular sealing face bearing against the other seating area in sealing relationship therewith, a sealing means interposed between said second ring and said shaft, and a spring in the hollow compressed between said nylon ring and said second ring to provide a driving connection between said nylon ring and said second ring for rotating the latter with the shaft, to urge said annular sealing face into engagement with said last mentioned seating area and to maintain the axial position of said shaft in said housing.

References Cited in the file of this patent UNITED STATES PATENTS 1,859,436 Durdin May 24, 1932 1,862,887 Durdin June 14, 1932 2,277,196 Arf Mar. 24, 1942 2,606,045 Forges Aug. 5, 1952 2,619,040 Maisch Nov. 25, 1952 2,758,548 Rockwell Aug. 14, 1956 2,836,440 Brumagim May 27, 1958 2,853,020 Hollinger et a1 Sept. 23, 1958 2,882,830 McDufIie Apr. 21, 1959 2,892,413 Erikson June 30, 1959

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