US2140965A - Engine starting mechanism - Google Patents

Description

Dec.H 20,' 1938. N R. M. NARDoNE 2,140,965

' ENGINE STARTING MECHANISM Original Filed March 22, 1930 2 Sheets-Sheet 1 Det; 20, 1938. R, M, NARDONE 2,140,965

ENGINE STARTING MEGHANISM Original Filed March 22, 1930 2 Sheets-Sheet 2 Patented Dee'. zo, i938 @PATENT olf-'Fics' 2,140,985 ENGINE STARTING MECHANISM Romeo M. Nardone, East Orange, N. J., assignor to Eclipse Aviation Corporation. East Orange, Nr.1., a corporation of New Jersey application March 22, 1930, Serial No. 438,220. Divided and thi! application March 16, 1937, Serial No; 131,268

6 Claims. (Cl. I4-50) This invention relates to starting apparatus for internal combustion engines.

One of the objects of the invention. is to provide novel engine starting mechanism that is i simple and rugged in structure, light and compact, and especially well adapted for use with aircraft engine installations. A,

Another object of the invention is to provide a fluid pressure actuated engine starter involving a novel construction and inter-relationship of the parts constituting the fluid pressure actuating means. The above and other objects will appear more fully in the detailed description of the invention which follows. 1 One embodiment of the invention is described and illustrated in the accompanying drawings, ..2

but it is to be expressly understood that these drawingsare for the purpose of illustration only, and are not to be construed as a definition` of the limits ofthe invention, reference being had for this purpose to the appended claims.

In the drawings:

Fig. 1 is a longitudinal sectional view of one form of the present invention, taken on line I-2 of Fig. 2;

Fig. 2 is a transverse sectional view taken on line 2--2 of Fig. l; and Fig. 3 is a drawn out perspective view of a piston of the iiuid pressure actuating means and a portion of its cylinder.

Referring now to the drawings, wherein like reference characters indicate like parts throughout the several views, the embodiment of the present invention shown therein comprises" an engine starter of the type having an engineengaging member which is adapted for advancement into cranking engagement with a member of the engine to be started, and for cranking actuation thereafter by power means through a suitable train of reduction gearing and other drive transmission means, the power means comprising a novel fluid pressure engine, the pressure of the fluid supplied to which is also adapted for causing movement of the engine engaging mem- 45 ber into cranking engagement with the engine member.

In the form shown, the engine engaging member. drive transmission means, and reduction gearing are suitably supported and housed within 50 a substantially cylindrical casing section 4 which is detachably connected to the housing or crankcase 5 of the engine to be started by suitable means such as screws B, while the power actuating means are in turn suitably housed and supsl ported in a second casing section Iwhich is detachably connected to casing section l by any suitable means (not shown). Section 1 is open at its outer end in order to facilitate assembly and maintenance of the power actuating means, and is provided with an end plate 9 detachably 6 secured thereto by any suitable means and forming a closure for the casing,a bearing for the shaft ofthe power actuating means, and distributing passageways for the motive fluid. y The power actuating means preferably comu prises a uid pressure engine or motor, the crankshaft of which is drivably connected to the engine-engaging member of the starter, through a suitable reduction gear train and other drive transmission means. In the form shown, a plurality of radially arranged cylinders, one of which is shown at 9, are secured by any suitable means (not shkown) to the outer end of casing section 1, the upper ends of the cylinders extending radially from said casing. 'I'here may be any suitable number ofthese cylinders arranged singly or in pairs, but preferably three cylinders are employed. Each cylinder 9 is provided with a cylinder liner I9 which extends within casing l and forms an expansion chamber i I within which 25 a piston l2 is reciprocated, said liner being held in its proper position within the casing by means of a shoulder I3A which is clamped between cylin-- der casting 9 and casing section 1.

Novel means are provided for reciprocating 3o pistons i2, which means do not require any mechanical connection between the pistons and the crankshaft but only a surface contact between these members. As illustrated herein and also in my applications` Nos. 438,220 (now Patent No. 35 2,081,760) and 6,555 filed on March 22, 1930 and February 14, 1935 respectively the crankshaft is y built up of two main elements Il and I5, each of which comprises a shaft portion I la and I 5a, a, crank pin portion and a counterweight portion llc andvlic. These two elements of the crankshaft are secured together by any suitable means such as a screw I6 passing through the crank pin portions. Shaft portion Ila is suitably journaled as by means of a roller bearing I'I in a 5 boss I8 formed in the inner face of casing section 1, while shaft portion lia is suitably journaled as by means of a. ball bearing I9 in a boss 2li formed integrally with and centrally of end plate 8. Piston I2, which is made of very light mate- 50 rial and left hollow inside in order to reduce its weight to a minimum, may be provided, if desired, with a central web or rib 2l formed integral therewith and extending a substantial distance below the plane of the bottom edge of the piston foithe purpose of contacting with the crankshaft. As shown more clearly in Fig. 3, web 2| is thicker at its sides, which form an extension of the surface of piston I2, than it is in its center portion, and is provided at its bottom with an enlarged shoe retaining portion 22 which is suitably grooved to receive a metal bearing shoe 23, the bottom of which is suitably rounded for a bearing contact with the outer race of a roller bearing 24 which surrounds the crank pin formed by'the crank pin portions of crankshaft elements I4 and I5.

Since web 2l, 23 extends transversely across piston I2 on a diameter thereof, and since this web must contact with roller bearing 24 and at times extends between counterweight portions I 4c and I5c, it is desirable that suitable means be provided to prevent piston I2 from turning about its axis within the cylinder. For this purpose, a pin 25 (Figs. 2 and 3) having an enlarged cylindrical head 26 and a flattened portion 21 projects through a hole in the lower portion of cylinder liner I0, the flattened portion 21 engaging a longitudinal groove 28 formed in the outer surface of piston I2 and web 2I. A groove 29 is formed in the inner surface of casing section 1 to accommodate the enlarged head 26 of pin 25, which construction not only allows the independent assembly of the cylinder 9, liner I9, and piston I2, and prevents the piston from turning relative to the liner, but also prevents the entire liner and piston vassembly from turning after assembly relative to the cylinder and casing section 1.

Suitable means are provided for supplying and exhausting a. motive fluid to the above described fluid pressure engine, said means, in the present embodiment, comprising passageways disposed within casing section 1, end plate 8, and cylinders 9, and utilizing the shaft portion I5a as a distributing valve. As shown, each of the cylinders 9 is provided with a channel 30 opening into the top of expansion chamber II through a port 3I formed in liner I8, which channel is a continuation of a similar channel 32 formed in end plate 8. These channels act as both intake and exhaust passages for the cylinders. A main supply passage 33 and an exhaust opening 34 are also provided in end plate 8, supply passage 33 being suitably connected, as by means of a supply pipe 35 and a main control valve (not shown) in said pipe which may be conveniently located as in the cockpit of an aeroplane, to a source of fluid under pressure (not shown), such as a compressed air tank, while exhaust passage 34 may discharge directly into the atmosphere. Main supply passage 33 and channel 3D, 32 lead to the interior of boss 20 within which shaft portion I 5a of the crankshaft is journaled. Interposed between the interior of said boss and the crankshaft, and xedly secured to the former, is a valve bushing 36 which is provided with a plurality of ports registering with the respective passages in end plate 8. A main supply port 31 registers with passage 33 and extends annularly around the interior of bushing 36, and a plurality of combined supply and exhaust ports 38 register with passages 30,

Shaft portion I5a of the crankshaft, which extends within bushing 36 and rotates relative thereto, is provided with a pair of longitudinal grooves or passages such that as it rotates within bushing 36 it performs the function of a distributing valve. For this purpose, a supply groove 39 is provided intermediate the ends of shaft portion I 5a, and of sufficient length to connect main supply port 31 with any of the combined supply and exhaust ports 38 whenever the crankshaft is in such a position that said groove registers with one of the latter ports. The second or exhaust groove 40 is formed in the outer end of shaft portion I5a, suitably located circumferentially on said shaft with respect -to supply groove 39, approximately 180 therefrom, and is of sufficient lengthvto connectthe p orts 38 with the main exhaust opening 34.

'Ihe rotation of the crankshaft of the fluid pressure engine is transmitted to the engine-engaging member by suitable means including a' train of reduction gearing and other drive transmission means. The reduction gearing, in the embodiment shown, comprises a large internal gear 4I which meshes with and is driven by a pinion 42 suitably secured to shaft portion I4a of the crankshaft as by splines 43 or equivalent means. Internal gear 4I is drivably connected in any suitable manner, as by means of providing the shaft with flattened surfaces such as the one indicated at 44, to a hollow stub shaft 45, the inner end of which is rotatably supported in a boss 46 formed in the inner face of casing section 1, and the outer end journaled in a ball bearing 41, the outer race of said bearing being carried by a rotatable member of the drive transmission means later to be described. An enlarged portion 48 of stub shaft is provided intermediate boss 46 and hub 49 of gear 4I, and prevents longitudinal movement of said shaft and the assembly thereon.

Formed integral with hub 49 of gear 4I is a pinion or sun gear 50 which meshes with a plurality of planetary gears 5I, preferably three in number, the planetary gears in turn engaging with a stationary internal ring gear 52 secured to the interior of casing section 4in any suitable manner as by means of screws (not shown). Dowel pins 53 preferably extend into casing 4 and ring gear 52 to prevent shearing of the screws. Planetary gears 5I are journaled on bushings 54 surrounding sleeves 55 which are countersunk in and mounted on an annular base plate 56, which forms a part of the drive transmission means later to be described, by means of screws 51, and are held in proper operative position on the bearings thus formed by means of a retaining ring 58.

The drive transmission means, which includes base plate 56, is adapted to transmit the rotation of the iiuid pressure engine crankshaft as received by said plate through the reduction gearing, to a driving or engine-engaging member which is adapted to be moved into engagement with and to crank a member of the engine to be started. In the form shown, base plate 56 is preferably formed integral with a cylindrical driving barrel member 59 which is rotatably supported in an elongated boss 6D formed integral with and located centrally within casing section 4 adjacent its connection with engine casing 5. Driving barrel 59 also carries the outer race of ball bearing 41 previously referred to. Suitable means may be provided to prevent longitudinal movement of driving barrel 59 within boss 6I), and, in the form shown. comprise a washer 6| abutting the inner end of boss 60 and a snap ring surrounding the inner end of driving barrel 59 and abutting washer 6I.

A driving or engine-engaging member 63 having a clutch jaw 64 is slidably supported in and drivably connected to driving barrel 59 by any suitable means such as splines 65, and is adapted to be moved into engagement with a corresponding clutch jaw 83 formed on a rotatable member of the engine to be started, for the purpose of cranking the latter. The splined engagement between driving member 83' and driving barrel 88 a provides a positive driving connection between these members and also allows the former to be moved longitudinally into cranking engagement with engine clutch jaw 88 by suitable means later to be described.

An oil sealing member 81 is suitably secured between the flanges of starter casing 4 and engine casing 8, and surrounds driving member 63 and the inner end of the drive transmission means to prevent oil from leaking from within engine casing l back into the starter mechanism, said member 81 being provided with a washer 88 of leather or other suitable material which is secured thereto by any suitable means such as a retaining ring 83 and rivets 1.

m It is desirable that the movement of driving member 83 into cranking engagement with the engine member be automatic, and means. have therefore been providedwhich are actuated by the pressure of the fluid admitted to the fluid g5 pressure engine and which are effective to move driving member-83 into cranking engagement whenever the fluid pressure engine is actuated. In the form shown, an operating rod 1i extends centrally through the bore of stub shaft 45 upon 80 which the reduction gearing is mounted, with its inner end bearing against the outer end of driving member 83. The outer end of operating ro'd 1I abuts the face of a piston 12 which is housed within a recess 13 formed in end plate 8, and is freely slidable therewithin. A small passageway 14 connects the recess 13 with the main supply passage 33 to which the fluid under pressure for operating the fluid pressure engine is supplied by means of pipe 35. With this construction it is n apparent that whenever the main control valve (not shown) in supply pipe 36 is opened, fluid under pressure will not only besupplied to the fluid pressure engine but will also act on piston 12 to force driving member 83 to the left, as viewed inFlg. 1, into engagement with the engine mem- It is also desirable, in some instances, to operate a booster magneto or other current means from the starter mechanism when the engine is w` being started so as to insure proper ignition and quick starting, and such a magneto may be drivably connected to the, reduction gear train so as to be rotated at a high speed during the cranking operation. In the present embodiment, 88 a booster magneto 15 of any suitable type is mounted on starter casing section 1 vand secured thereto by any suitable means. The shaft 16 of the magneto carries a clutch member 11 which is keyed thereto and held thereon by a nut 18, .0 and which is provided with a plurality of teeth 19 which engage corresponding splines 80 formed on the interior of a second cupped shaped clutch member 8| rotatably mounted in a boss 82 formed in the lower part of casing section 1. A u short shaft 83 is made integral with clutch member 8i and has gear teeth formed on its surface intermediate its ends, constituting a pinion 84 which meshes with internal gear 4I. The inner 7 end of shaft 83 is journaled in a suitable strut bearing member 85 which is secured to casing section 1 by any suitable means such as a screw 86. Pinion 84 and gear 4l constitute step-up gearing driven by the fluid pressure engine and `housed 1| within the starter casing, to which shaft 18 of the booster magneto may be drivably connected by means of clutch members 11 and 8i.

The operation of the apparatus is as follows: The normal at rest position of the parts of the starter mechanism is as shown in Fig. 1, with 5 clutch :law 84 of driving member 83 disengaged from engine clutch Jaw 68. When it is desired to crank the engine with which the starter is associated, the main control valve (not shown) in. supply pipe 35 is opened, and a motive fluid 10 under pressure is supplied to the fluid pressure engine through the main supply passage 33. From main supply passagey 33 -the fluid is conducted to one of the cylinders of the fluid pressure engine through main supply port 31, supply 15 groove 38 of shaft portion lia of the crankshaft, combined supply and exhaust port 38, channels 32 and 30, and port 3| of the cylinder which is on its pressure stroke. The fluid under pressure enters expansion chamber il and acts'upon pis- 20 ton i2 forcing it downward, and, through the contact between bearing shoe 23 and roller bearing 24 of the crank pin, exerts a force on the crankshaft and rotates the same. After the crankshaft has rotated through approximately 180, 25 exhaust groove 48 registers with supply and exhaust port 38 and connects the interior of expansion chamber ii with the atmosphere through port 3i, channels 30, and 32; port 38, exhaust groove 40, and main exhaust opening 34. At this time piston Ii is being driven upwardly by the action of roller bearing 24 on shoe `23, the positive drive of the crankshaft being derived from one of the other cylinders on its pressure stroke, and the expanded uid is exhausted to the atmosphere.

Simultaneously with the admittance of uid under pressure to the uid pressure engine, fluidis admitted through passage 14 to recess 13, and acts upon piston 12 to force operating rod 1I to 40 the left, as viewed in Fig. 1, and to move driving member 83 and its clutch jaw 64 into cranking engagement with engine clutch jaw 88. Rotation of the crankshaft I4 is then transmitted through pinion 42, internal gear 4|, pinion 50, planetary 45 gears 5I, base plate 58, driving barrel 58, and splines 65 to the driving member 63, and the latter is rotated, cranking the engine to be started.

When the engine starts under its own power, 50 engine clutch jaw 86 will overrun clutch jaw 64 and, due to the inclined shape of the teeth thereon, will force clutch jaw 64 and driving member 63 to the right out of engagement with the engine clutch jaw. After the supply of fluid to the fluid pressure engine has been shut off and the starter mechanism rendered inoperative, the pressure of any fluid which might remain within the passageways of the starter is insufficient, due to leakage and other causes, to force driving 00 member 83 to the left into engagement again with the engine member, particularly in view of the inclination of the jaw teeth and the relatively high peripheral speed of the clutch jaw 88, as 65' contrasted with the zero, or at best negligible, peripheral speed of the clutch Jaw 64.

Should a backfire of the engine being started occur during the starting operation, the various parts of the starter mechanism will be adequately protected against injury since the reverse torque caused by the backre will be transmitted back through the drive transmission means and reduction gearing to the crankshaft of the fluid pres- ,sure engine where'the shock will be cushioned 75 due to the compressible character of the motive uid.

This application is a division of my application No. 438,220 led March 22, 1930, now Patent No. 2,081,760 of May 25, 1937.

What is claimed is:

1. In a device of the class described, a crankshaft having a pair of counter-weights axially spaced thereon and both disposed on the same side of said crankshaft, a crank-pin integral with said crankshaft and disposed on the opposite side thereof, a roller bearing surrounding said crankpin and disposed between the opposing faces of said counter-Weights, means for rotating said crankshaft comprising a plurality of straight sided web members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each frictionally contacting the peripheral surface of said roller bearing, and means for preventing rotation of said web members about said radial lines, said means comprising grooves cut longitudinally of said web members, and a corresponding number of transversely disposed pins secured against movement and disposed within said grooves.

2. In a device of the class described, a crankshaft having a pair of Acounter-weights axially spaced thereon and'both disposed on the same side of said crankshaft, a crank-pin integral with said crankshaft and disposed on the opposite side thereof, a roller bearing surrounding said crankpin and disposed between the opposing faces of said counter-weights, means for rotating said crankshaft comprising a plurality of straight sided members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each frictionally contacting the peripheral surface of said roller bearing, and means for preventing rotation of said reciprocable members about said radial lines, said means comprising grooves cut longitudinally of said reciprocable members, and a corresponding number of transversely disposed pins secured against movement and disposed Within said grooves.

3. In a device of the class described, a crankshaft having counter-Weighted means on one side of said crankshaft, a crank-pin integral with said crankshaft and disposed on the opposite side thereof, a roller bearing surrounding said crankpin, means for rotating said crankshaft comprising a plurality of straight sided members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each frictionally contacting the peripheral surface of said roller bearing, and means for preventing rotation of said reciprocable members about said radial lines,

said means comprising grooves cut longitudinally of said reciprocable members, and a corresponding number of transversely disposed pins secured against movement and disposed Within said grooves.

4. In a device of the class described, a crankshaft having a pair of counter-Weights axially spaced thereon and both disposed on the same side of said crankshaft, a crank-pin disposed on the opposite side thewof, a roller bearing surrounding said crank-pin and disposed between the opposing faces of said counter-weights, means for rotating said crankshaft comprising a plurality of members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each contacting the peripheral surface of said roller bearing, and means for preventing rotation of said reciprocable members about said radial lines, said means comprising grooves cut longitudinally of said reciprocable members, and a corresponding number of transversely disposed pins secured against movement and disposed Within said grooves.

5. In a device of theclass described, a crankshaft having counter-weighted means on one side of said crankshaft, a crank-pin disposed on the opposite side thereof, av roller bearing surrounding said crank-pin, means for rotating said crankshaft comprising a plurality of members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each contacting the peripheral surface of said roller bearing, and means for preventing rotation of said reciprocable members about said radial lines, said means comprising grooves cut longitudinally of said reciprocable members, and a corresponding number of transversely disposed pins secured against movement and disposed within said grooves.

6. In a device of the class described, a crankshaft having a pair of counter-weights axially spaced thereon, a roller bearing surrounding said crankshaft and disposed between the opposing faces of said counter-weights, means for rotat- 'ing said vcrankshaft comprising a plurality of straight sided members reciprocable along equally spaced lines radiating from the axis of said crankshaft and each contacting the peripheral surface of said roller bearing, and means for preventing rotation of said reciprocable members about said radial lines, said means comprising grooves cut longitudinally of said recip1ocable members, and a corresponding number of transversely disposed pins secured against movement and disposed within said grooves.

ROMEO M. NARDONE.

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