US 2594194 A
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April 22, 1952 c. s. METSGER OIL SEAL FOR ENGINE STARTERS Filed Aug. 19, 1947 INVENTOR. EHHHLEE 5. [TIE 7555/? .BY
Patented Apr. 22, 1952 UNITED STATES. PATENT OFFICE QIL SEAL FOR ENGINE STARTERS Charles S. Metsger, Morris Plains, N. J assignmto Bendix Aviation Corporation, Teterboro, N. J., a corporation of Delaware Application August 19, 1947, Serial No. 769,425
subject to contact with the engine oil whiletheengine is running, but,- when the plane is normally parked are not subject to contact with the oil.
Such occasional oil contact with a normally horizontal starter, which oil leaks intothe starter only when the engine is running, hasbeensevere enough to have caused many suggestions forpreventing such leakage, certain of which have been satisfactory after considerable experimentation and trial.
When such starter is to be adapted to have its jaw at its upper end facing-upwardly as in the bottom of a, crank case of a helicopter engine, the problem of preventing leakage is appreciably more difiicult. In such case, the sealing means is subject, not only to oil when theengine is run-,- ning, but to a head of oil of as much as six inches when the plane is parked, so that, instead of having to take careof onlyloccasional leakage past the jaw, as in former practice, the sealing means hereof is called upon to operate efiectiv ely under more diificult conditionsjand at all times.
Also, under the more difficult conditions in the case of a starter which is adapted for-direct cranking, any usual means for irictionallyrestraining the jaw against rotation for causing the jaw to advance axially into engagement withxthe engine jaw, would be. more continuously subject to a greater amount of oil tending, to reduce its friction holding efiiciency.
An objectfof the invention is to provide novel means for sealing a starter of the axiallymovable rotatable jaw type when the jaw of the latter is subject to conditionssuch as under the head of oil aforesaid, but which will also be effective under other conditions of service.
Another object is to provide means of the aboveindicated character which may be applied to a, standard starter, normally adapted for operation in the horizontal position indicated. which application may be effected with substantially'a minimum of change.
Another object is to provide a starter which shall be particularly adapted for employment in a helicopter, as indicated, andin other applications to be benefited by the invention.
Another object is to provide an arrangement wherein a plurality of units, each having-com bined friction and sealing characteristics, are disposed in tandem at opposite sides of a chamber along the jaw, which units operate not only 'as sealing means but also as friction meansforre straining the jaw against rotation to eflectits axial movement engaging it to theengine jaw:
Another object is to provide a device of theabove-indicated character which is simple" and durable in construction, economical to manufac ture, and effective in its operation.
The above and other objects and ieatures-of-the invention will appear more fully hereinafter from a consideration of the following description-taken in connection with the accompanyingdrawing wherein two embodiments of the invention-are illustrated by way of example.
In the drawing:
Figure 1 is a side view, generally in section, but
having parts in elevation, of a portion-0i s rengine starter embodying the invention in one form;
Figure 2 is a view similar to a portion ofFigure 1 of a starter embodying the invention inane other form.
Referring to gear train in a usual manner.
The barrel l2 encloses and isoperatively con nected to an axially stationary cylindrical nut H by a torque limiting disc pack 16 having inter, layered discs splined to the barrel and the nut,
respectively, which discs are adjusted axiallyagainst an end wall it of the barrel in predetere mined friction relation to each other by springs 20 and a ring nut 22 threaded to thebarrel l2 inside the latter.
A screw shaft 2 4 has long-lead thread relation to the nut l4 inside the latter, and isprovided with a spline connection 2:6 to a jawmember Figure 1, the starter illustrated of a type adapted for direct crankingv comprising a housing Ill enclosing a rotatable barrel l2, which: is driven by a motor through a speed reducing,
end of a spring 42 having its other end pressing against a backing ring 44 held by a lock ring 46 in a groove of the screw shaft 24.
In combination with the above-described elements, the invention comprises a hollow wall bafile 48 comprising annular elements 50 and 52, respectively, nested in spaced relation to the shank 3| and to each other to forni a chamber 54 therebetween. The element 50 has a cylindrical intermediate portion 56, a radially inwardly extending flange 58 and a radially outwardly extending flange 60. The element 52 has a cylindrical intermediate portion 62 spaced from the flange 64 adjacent to the flange 58 spaced thereagainst the passage of oil through the jaw at the from, and a radially outwardly extending flange L sponding reference characters.
66 adjacent to, but spaced from, the flange 60.
The elements 50 and 52 are held in sealed relation to, and spaced from, each other as by a body j 68 to define the chamber 54, and having a drain port 10 adapted to receive a coupling '12 for a conduit leading to a location exteriorly of the starter, such as overboard, to a collector tank, or to a trap from which it is automatically returned to the engine oil system.
Yieldable rubber-like ring units 1'4 and 16, secured to the flanges 58 and 94, respectively, as by vulcanizing through holes and at opposite sides of the flanges, are'each provided with a labyrinth of inner surface grooves next to the shank 3| of p the jaw againstwhich they are held, as by garter springs 18 and 80, respectively, there being two of the garter springs 18 and one spring 80, in this instance. The springs 19 are shielded by a cover 82.
The starter is held in position relative to a crank case 84, as by shoulder nuts 85 on studs 86.
In operation, when the barrel I2 is drivingly rotated, it acts, through the discs of the pack IE, to turn the nut l4. With the screw shaft 24 splined by the connection 26 to the jaw member 28, and the latter constrained against rotation by the combined sealing and friction holding units" and 16, the first turning of the barrel l2 and the nut [4 causes the screw shaft 24 to advance upwardly, as viewed in the drawing, from the retracted or lower position shown to a position in which it engages the engine jaw 30, subsequent to which, with a usual shoulder on the screw shaft 24 in engagement with a usual shoulder on the nut 14, the jaw 28 drives the jaw 30 to normally start the engine.
When the engine starts, the jaw 30 overrides the jaw 28 against the action of the spring 42, and when the starter motor is deenergized, the jaw 30 cams the jaw 28 in a usual manner back to the retracted position shown. If, for any reason, the
engine jaw element 30 abnormally resists turn-- ing, or if the engine backfires, the reaction is abthis instance, by gravity to the outlet F2 for disposal as above indicated.
. 6.5 The structure of Figure '2, in contradistinction sliding seal I08, as by a tightly press fitted disc or cover I l I.-
The remaining parts of Figure 2, corresponding to parts of Figure 1, are designated by corre- Although only two embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts may be made to suit requirements.
What is claimed is:
A seal for. use in an engine starter having a housing including an end portion having an opening therein and a rotatable and axially movable jaw member having a cylindrical shank portion extendingthrough the opening in said end portion, comprising an outer bafile plate secured to said housing and having an inwardly extending circumferential flange, a resilient sealing ring, said sealing ring being amxed at its outer peripheral edge to said circumferential flange and its inner edge forming a wiping contact with said shank portion, a garter spring for biasing said inner edge into contact with said shank portion; an inner bafile plate secured to said housing and having an inwardly extending circumferential flange, a resilient sealing ring, said sealing ring being affixed at its outer peripheral edge to said circumferential flange and its inner edge forming a wiping contact with said shank portion, a garter spring for biasing said inner edge into contact with said shank portion; said inner and outer. bafiie plates being spaced apart to form a collecting chamber along said shank portion, and oil outlet means from said chamber to provide effective drainage therefrom.
' CHARLES S. METSGER.
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