US2762657A - Nozzle - Google Patents

Description

Sept- 11, 1956 LA RQY A. wlLsoN 2,762,657

NOZZLE Filed sept. 1s, 195s IN VENTOR LA ROY A. WILSON ATTORNEYS United States atent t,/-2`,762,6s7 gfrriozzmt La Roy Wilson, A.'alroa'lzirlr, Application September v15, v1953, Serial No. 380,383

'2 Claims. (Cl. 299-120) (Granted under Title 35, U. S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in nozzles, particularly those used in jet engines.

Most nozzles in use today in jet propulsion engines consist essentially of a body, insert and strainer. Fuel is forced under various pressures through the strainer and the insert to the tangential slots that direct the fuel to a swirl chamber prior to its discharging from the nozzle oritice. The dimensions and relative locations of the tangential slots, the swirl chambers and the orifice determine the pressure-flow characteristics, the spray angle and distribution as well as the drizzle po-int of the nozzle (lowest fuel pressure at which the nozzle produces a spray, and

below which it discharges drops or a stream of fuel). These qualifications of fuel nozzles must be held to close tolerances when used with turbo jet engines, something that has proved to be very dii-heult.

It has been the practice to thread the nozzle insert into its chamber in the nozzle body, and bring the inner end of the insert against the nozzle body wall adjacent to the nozzle orifice. Since the insert was rotated as it advanced linearly in the nozzle body, the swirl slots were crushed or burred. A burr or other restriction in one or more of the swirl slots causes faulty spray patterns, reduced total flow, and often alters the angle of spray. Those nozzles which were assembled without injury to the swirl slots could seldom if ever be disassembled for cleaning and returned to a properly operative assembly. The rejection rate of overhauled nozzles has been greater than new nozzles. An object of this invention is to provide a fuel nozzle with an insert that is moved linearly and without rotation into the nozzle body until the discharge end of the insert comes to rest against a wall in the nozzle body thereby precluding all groove mutilation caused by insert rotation.

More specifically an object of the invention is to provide a fuel nozzle body with an insert that has a shoulder against which a nut is operable, the nut being threaded in the nozzle body, linearly moving the nozzle insert without rotating it, until it comes to rest against an abutment in the nozzle body adjacent to the nozzle orice.

Another object of the invention is to provide the nozzle insert described above, with a tool slot to hold it from rotating, while the nut accessible from the exterior of the nozzle body, is rotated.

Other objects and features such as ordinary fuel pressure inherently holding the insert firmly in place Within the body if the retaining nut is loose, will become apparent in following the description of the illustrated form of the invention.

in the drawing:

Fig. 1 is a longitudinal sectional view of the nozzle and,

Fig. 2 is a transverse sectional View of the nozzle taken on the line 2-2 of Fig. 1.

The nozzle body in the drawing is of usual form,

2,762,657 Patented Sept. 11, 1956 hun* having a threaded end 12 to which a fuel conduit is adapt; ed wto be 'attached in order to supply fuel under pressure to 'the insert chamber which is a'n'a'xial passageway in the body 10. lin'sert 14 is disposed in the passageway and it has a sha-nk 16 lonwlhich there is a ,peripheral shoulder v18 Vl-laving `a flat radi-al contact face on the outer side thereof, this shoulder being the only deviation from usual insert forni. Accordingly, the insert also includes a longitudinal fuel passage 'that opens into Aradial passages 22, through which fuel enters chamber 24. The inner endof the insert 14 has a beveled wall 26 seated upon beveled wall 28 of the nozzle body, the latter Wall surrounding fuel discharge orifice 30. In as much as there are a number of tangential slots 32 in wall 26, fuel from chamber 24 is allowed to enter swirl chamber 38 between orifice 3i) and the inner end of insert 14, and finally discharge through orifice 30.

ln the usual case, the insert is provided with threads engageable with threads 40 in the insert chamber, in order to hold the insert xed in the nozzle body. The disadvantages of this technique have been mentioned previously. In the illustrated case, the insert 14 is simply slid into the insert chamber, without having to rotate insert 14. Therefore, wall 26 is brought to rest on wall 28 without injuring the slots 32 in any way. Then, the insert is held against rotation by a screw driver or other tool engaged with screw driver slot 44 at the outer end of insert 14. Means for holding the insert 14 firmly in place within nozzle body 10 are provided, and preferably -consists of a nut 46 having external threads engageable with threads tti and an internal bore that fits closely over shank 16. Means to receive a tool, as slots 48 for a Spanner wrench, are provided o-n the nut 46 so that .it may be threaded in the insert chamber while insert 14 is held by a screw driver or the like. ln this way the insert does not rotate, but is moved linearly into the nozzle body 10 by nut 46 since the nut contacts shoulder 18 as the nut is rotated, pushing shoulder 1S and the entire insert 14 into opera-tive position.

In order to disassemble the nozzle, the nut 46 is removed and insert 14 taken out of the insert chamber. lt is understood that various modifications may be made without departing from the following claims.

What is claimed is:

1. In a fuel nozzle, a body having a tubular insert chamber with threads at one end and an orifice at the other end; a hollow cylindrical insert in said insert chamber having a slotted end forming a partial closure for said orice, an annular shoulder surrounding said insert intermediate the ends thereof, said shoulder having a at and radial contact face on the chamber inlet side thereof, and radial passages between the shoulder and orifice end of said insert communicating with the hollow insert interior; means in said insert fo-r accommodating a tool to prevent insert rotation; and a nut consisting of a solid inelastic cylindrical block having a central perforation through the axis thereof for free sliding movement on said insert at the chamber inlet side of said shoulder, external threads for engagement with the internal threads of said chamber, and a flat annular contact face on the chamber outlet side thereof for engagement with said shoulder, whereby on nut rotation while said insert is retained from rotation, the slotted end of said insert may be compressed in a linear direction against said orifice without rotation thereof.

2. In a fuel nozzle, a body with a generally cylindrical insert chamber having internal threads lat one end, an orifice at the other end thereof, `and a tapered wall surrounding said orifice; an elongated insert disposed in said chamber between the threaded end and orifice thereof, said insert having an axial passa-ge therein; means for preventing rotation of said insert; a peripheral shoulder formed on said insert intermediate the ends thereof, said shoulder having a flat radial surface on the chamber inlet side thereof; a tapered wall lat the orice end of said insert having grooves therein for directing fuel into said orifice; radial passages in said insert between the shoulder and tapered wall communicating With said axial passages and grooves, said insert being spaced from the internal threads of said nozzle body chamber; and a nut consisting of a solid inelastic cylindrical block having a central smooth perforation through the axis thereof for free sliding movel() ment on said insert at the inlet side of said shoulder, said nut having external threads for engagement with the intei-nal threads of said chamber, a flat annular Contact face on the chamber outlet side thereof, and means permitting rotation thereof from points exterior to said body whereby, on rotation of said nut While preventing rotation of said insert, axial force only is applied to said iiisert to compress the grooved insert end into close engagement with the nozzle orice.

References Cited in the le of this patent UNITED STATES PATENTS 1,982,228 Murphy NOV. 27, 1934

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