US2093325A - Engine starter - Google Patents

Description

Sept. 14, 1937. R. P. LANSING ENGNE STARTER original #Filled May 2o, 1932 lll! l Patented Sept. 14, 1937 ENGINE STARTER Raymond P. Lansing, Montclair, N. J., assignor,

by mesne assignments, to Eclipse Aviation. Corporation, East Orange, N. J., a corporation of New Jersey Original application May 20, 1932, Serial No.

612,624. Divided and this application February 26, 1934, Serial No. 713,047

2 Claims.

This invention relates to starting mechanism for internal combustion engines, and more particularly to starters of the power turning gear type.

An object is to provide an engine starter or other turning gear embodying novel means for holding the cooperating elements of the torque l multiplying gear train in assembled relation.

In transmitting torque from a source to a stationary member, a strain is placed upon the parts of the latter at the moment it is started and at moments when a sudden change in load occurs. These strains endanger the life of such stationary member as well as the operation of the entire plant. It is, therefore, a further object of the present invention to provide, in conjunction with the torque multiplying means above referred to, novel mounting means for an engine vaccessory whereby torque reaction between the engine and said accessory is yieldingly resisted; said accessory being adapted for movement as a unit relative to said engine.

For claims to such accessory mounting means, per se, reference is to be had to my Patent No. 1,979,162 issued as a result of application No. 612,624, filed May 20, 1932, of which application the present one is a division.

A still further object is to provide an engine starter which is rugged in construction, inexpensive to manufacture, and particularly adapted for use with small aviation engines.

The above and further objects and novel fea'- tures of this invention will more fully appear from. the -following detailed description when taken in connection with the accompanying drawing wherein one embodiment of the invention is illustrated. It is to be expressly understood, however, that the drawing is for the purpose of illustration only and isnot designed as a denition of the limits of the invention, reference being had for this v'purpose to the appendedv claims.

'Ihe drawing is a side elevational view, partly in section, of an engine starting device constructed according to the present invention.

I- The illustrated embodiment of the present invention shows, `by way of example, an engine starter yieldingly mounted on the crankcase 4 of an internal combustion engine, said starter comprising driving means such as an electric motor 5 adapted to rotatably drive a starter jaw clutch member 6 through suitable gearing to be hereinafter described in detail. The starter jaw Gis adapted to be moved axially into and out of Aengagement with a complementary jaw 8 mount- (Cl. I4-305) ed onthe crankshaft 9, or an extension thereof, of an engine, whereby said crankshaft may be rotatably driven and the engine started.

The starting unit as shown is provided with suitable housing means comprising a main housing member I0 adapted to be removably secured in a novel manner to the crankcase 4 and a motor housing II rigidly attached to the outer face of said main housing member by means of a plurality of'elongated bolts, one of which is shown at I2. The extended portion of shaft I3 of motor 5 is rotatably supported in a suitable bearing I4 which is in turn mounted in the central hub portion of a transversely disposed wall or spider I5 that may be securely held in engagement with the inner end of housing I I by means of bolts I2.

Suitable torque multiplying means, including a simple and efficient reduction gear train, and novel supporting means therefor, has been provided to transmit the power of motor shaft I3 to a driven member at a reduced speed with increased torque. The gear train, as shown, comprises-a compound planetary gear member or pinion I6 having two sets of teeth Il and I8 cut thereon, the diameter and number of teeth of one set being somewhat less thanthose of the by means of bearings 24, the entire unit being retained on shaft I3 by a nut 25 on the reduced end portion of said shaft. If desired,'three gear members I6 may be employed, spaced 120 degrees apart and mounted in the manner shown. Preferably the bolts 23 are of the same number, and spaced to alternate with the pinion supporting shafts` (pins) l. I

The construction just described has Ythe advantage that the bearings I9 absorb the axial thrust as well as the radial pressure.

The larger portion I'I of member I6 is in constant mesh on one side with a pinion 26 suitably splined or keyed to shaft I3, and on its other side with a stationary internally toothed annular gear 2l secured between spider I5 and housing I0 by bolts I2. The smaller portion I8 of member IB is in constant mesh with gear teeth cut on the inner periphery of a bell shaped member 28 formed integrally with an inwardly extending hub portion 2,9 which is rotatably mounted in housing member IIJ by means of suitable bearings and out of mesh with the'engine jaw 8. Preferably, such means is constituted by a jaw clutch assembly consisting, as shown, of a shaft 35 threaded into lthe hub portion 29 of gear member 28. and provided with longitudinal splines at its outer end to receive the interiorly splined tubular portion of starter jaw 6. Secured to the ,inner end of shaft 35 is a stop nut 36 for limiting the outward movement of said shaft with respect to hub 29. Relative axial movement between starter jaw 6 and shaft 35 is limited by rod 31 extending through central openings in each of -these members. Preferably, a spring 38 surrounds the engine end of rod 31' bearing at one end against the inner face of starter jaw 6 and at its other end against the threaded shaft 35, the latter being provided with a recess into which a.I portion of spring 33 extends. The starter jaw 6 may be maintained on rod 31 by means of a nut 39 threaded thereon.

Preferably, automatic means are provided for insuringthe meshing of the starter jaw 6 with complementary jawl 9 associated with the vengine crankshaft 9. As shown, such means include a. light metal housing 40 which is rigidly held in place by means of an annular shelf 4I 'on a member,41, further to be described. In the particular structure illustrated, threearcuate members 42 surround the starter jaw 6 and are rotatably supported in an annular semi-circular channel 43 formed by outwardly bending the inner edge of housing member 40, each arcuate member having a bead which rests in said channel. A toroidal spring 44 received by grooves in the outer periphery of members 42 is provided for n exerting an inward pressure on said members, thereby maintaining them in frictional engagement with housing 40. Each of the members 42 is provided with a suitable lug or projection 45 which extends inwardly into a corresponding Awardly into 'mesh with the jaw 6 by virtue of the'coaction of the screw threads on shaft 35 and hub 29. Preferably, the jaws 6 and 8 are provided' with inclined teeth so that there will be an immediate disengagement of the starter jaw vwhen its speed of rotation :is exceeded by theA engine jaw 8, that is, jwheny the engine com.-

merces firing.

Meansl are providedvfforv yieldngly mounting the above described startingun'it, or similar apparatus, on the .'crankc'ase of an engine, in a manner such that the'entire unit is adapted for limited movement in its` pilot bearings relative -by a v'sharply changing torque or load is absorbed by suitable .yielding means, thus preventing injury to and strain upon the mechanism. In the preferred embodiment shown, the housing I0 is provided at its inner face with an annular flange 41 which has cut therein a plurality of arcuate pilotlslots 48 concentricfwith the axis of rotation of the starter mechanism and through which relative thereto.

I er face of flange 41 and adusting nuts 5I threaded onto the outer ends of said bolts. It is thus seen that the starter is held rmly against the crankcase by the pressure of springs 56 but is at the same time capable of lmitedaxial .movement also possible, due to slots 46 above described, and such movement is yieldingly resisted byy coil springs 56 provided in laterally-extending ears 52 (preferably two, diametrically disposed) the central axes of which are substantially perpen- 1g dicular to the axis of rotation of the starter unit. Extending through the ears 52 are bolts 54 which are supported at their ends in any suitable manner such as by brackets 55 integral with or rigidly attached to the engine crankcase 4. Nor- .21

mally the ears 52 are centrally positioned on the bolts 54, and the coil springs 56 surrounding said bolts on each side of said ears abut brackets 55. For assisting in the support and proper seating of the forward end of the starter housing, the 2 annular shelf or abutment 4I aforementioned, has an outer face beveled atan angle permitting it to rock on the beveled annular opening 51 in the crankcase 4.

In operation, the motor 5 is energized from a 3* suitable source of electrical energy (not shown) whereupon the shaft I3 rotates with the motor armature, and its motion is in turn transmitted through pinion 26, planetary gears I1, Il and internal gear za to the hub 2s. During the mi- 3 between hub 29 and shaft 35, whereupon the 4 screw threads of said two last named membersl coact and cause shaft 35 to move to the left, carrying starter jaw .6 into mesh with engine Jaw 6. It willbe noted that the speed of rotation of the starter jaw at the instant oi' meshing is 4` comparatively slight, thereby preventing a clashing of the Jaw teeth. As soon as the said laws have been'brought into engagement, thereby establishing a positive driving connection between the starter and the engine, the members 42 com- 5` mence rotating with the 4starter :law 6 and continue to do so during the cranking operation. As soon as the engine res and the speed of engine Jaw 9 exceeds that of the starter :law 6, the latter is movedy to the right by virtue of the inclined 5 teeth. l

As pointed out above, the inertia oi' the movable engine parts of theengine places a large sudden load upon the starter at the instant law f s isensaged witniawi s. 'as this sudden 10aa is ,0

placed upon thestarter, certain ot the springs 56- p yield and anew the engine starting una to rome bodily lby reason' of the pilotslots 4I, thus 'preventing anysudden shckorstrain-y uponthe .i starter gearingand the motor. In likemsnner, 0

these springs, aided bythe'resilient-members 5I, will absorb any shock occasioned o n the backfire of an engine and all variations in the load which may be placed on the driving unit. v

There has thus been provided a novel engine 7` starting mechanism which includes a simple and ,emcient compound gear train and whichl is well adapted for practical use, which may be easily and cheaply constructed and assembled from Limited rotary movement is 1r ure of such parts and facilitating overhaul. Novel means have also been provided in combination with said starter for yieldingly mounting the same on the crankcase of an engine to be started thereby protecting the parts thereof against sudden shocks and excessive or changing A loads.

What is claimed is:

1. In a device of the class described, the combination of a driving gear constituting the center of a planetary system, a planet carrier rotatable around said center, xed and rotatable orbit gears surrounding said carrier, a planet-pinion" meshing with said orbit gears, 'said planet pinion having a straight Walled pocket in each end face, and means adapted to roll along and in contact with the straight Walls of said pinion pockets t0 transmit to said carrier the axial component of the forces imposed upon said pinion.

2. In a device of the class described, the combination of a'driving gear constituting the center of a planetary system, a planet carrier rotatable around said center, fixed and rotatable orbit -gears surrounding said carrier, a planet pinion carrier' the axial component of the forces imposed 15 upon said pinion. t

RAYMOND P. LANSING.

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