US2110321A - Magneto - Google Patents

Description

March s, 1938. w. 1 BORGERD 'Er AL I 2,110,321

MAGNETO Origihal Filed Sept. 14, 19 6 s Sheets-Sheet 1 Z2 1 W" Z 20 i INVENTORS' ILL/4M [3000500 March 8,1938. w. F. BORGERD Er AL 2,110,321

MAGNETO Original Filed Sept. 14 1936 s Sheets- Sheet 2- INVENTOR!) Wu/Au 1':-

Bones)? 7 Aib ARMOA Ai iORNE March 8 1938. w. F; BORGERD ET AL 1 MAGNETO Original Filed Sept. 14, 1936 3 Sheets-Sheet 3 f IVIIIII f ay/117117111 INVENTORS ILL/4M [Baker/FD ILL/AM QBn-lmm/v 44/0 awvcm A #40410 Patented Mar. 8, 1938 UNITED STATES PATENT OFFICE MAGNETO Massachusetts Application September 14, 1936, Serial No. 100,706

Renewed October 22, 1937 11 Claims.

' This invention relates to improvements in magnetos.

. The invention has for an object the provision in a magneto of a housing, having a' mounting flange for direct connection to the crankcase of the engine which the magnetic is to serve, and a rotor shaft which is mounted in the housing and extends through the flange into the crankcase for connection to an engine-driven member, such as the cam shaft or a gear thereon, together with provisions in the housing of lubricant-conducting passages for supplying lubricant from the engine crankcase to all parts of the magneto which require lubrication.

other parts of the magneto.

According to another object of the invention, the rotor shaft, rotatably supported and lubricated as above set forth, extends from the mounting flange on the inner side of said housing to a timer case on the outer side of the housing and that part of the shaft which projects beyond the rotor into the timer case serves to actuate the breaker point mechanism.

According to another object of the invention, the rotor shaft which extends beyond the mounting flange into the crankcase, bears a gear for connection to an engine driven gear in the crankcase and between the gear and mounting flange an impulse driving mechanism is located in position to be lubricated from the crankcase.

Other objects will appear from the following description and will be pointed out in the appended claims.

' The invention will be disclosed with reference to the accompanying drawings, in which:

Fig. l is a sectional elevational view of a magneto embodying the invention;

Fig. 21s a cross-sectional view taken on the line 2--2 of Fig. 1 and illustrative of the impulse mechanism;

Fig. 3 is a fragmentary exterior elevational viewshowing the stationary abutment for the impulse mechanism;

55 4 is a view taken similarly to Fig. 2 but According to another object of the invention,

, bearing to keep the lubricant from the rotor and showing certain parts of the impulse mechanism in different relative positions;

Figs. 5 and 6 are cross-sectional views taken on the lines 5-5 and 6-6, respectively, of Fig. l; and

Fig. '7 is a fragmentary View taken from the right-hand end of Fig. 1 and showing the timer,- the cover for the timer casing having been removed.

Referring to these drawings, the magneto includes a hollow casing or housing I (Fig. 1) which in this case is a die casting of non-magnetic metal. This casing has aligned cylindrical openings H and I2 leading from opposite ends into an interior chamber l3 in which a magnetic rotor and the cooperating stator are housed.

The stator includes pole pieces M made up of soft iron laminations which are embedded one in each of two opposite side walls of the .chamber l3 (Fig. 6) during the die casting operation. These pole pieces at their upper ends are interconnected by a core l5 madeup of soft iron laminations and carrying the primary and secondary coils l6 and I1, respectively. The ends of core I5 are secured in place by clips l8 and screws l9, as indicated by dotted lines in Fig. l. The otherwise open upper end of chamber I3 is closed by a cap (Figs. 4 and 6) of molded insulating material, secured by screws 2| to casing I0. This cap contains a metallic socket 22 (Figs. 1 and 4) to receive the spark plug wire and is connected by a spring 23 (Fig. 1) to the high tension terminal 24, which is one terminal of the secondary coil H. The other terminal of this coil, together with one terminal of coil I6, is grounded by a wire 26 to one of the screws IS. A wire leads from the other terminal of coil ii to the timer, as will later appear.

The magnetic rotor revolves in the space between the lower ends of pole pieces I (Fig. 6) and is fixed to a shaft 21 (Fig. l) entirely sup ported, as will later appear, from bearings mounted in the passage II. The rotor consists of a pair of bar magnets 28 (Fig. 6) mounted in parallel relation, one on each side of the axis of the shaft 2I,-the latter being recessed to receive the central portions of the magnets. The ends of these magnets of one polarity engage in recesses in a laminated pole shoe 29, and the ends of opposite polarity engage in similar recesses in a similar pole shoe 29. The described assembly of magnets and pole shoes is held between two circular end plates 30 (see also Fig. 1)

of non-magnetic metal, suitably clamped together as by rivets 3| and 32.

The timing mechanism is mounted on the circular wall 33 of a cup-shaped casing, the cylindrical wall 34 of which fits in the passage l2 and is held in place by a screw 35. A cover 36, secured by screws 31 to casing l0, closes the outer end of passage l2 and completes an enclosure for the timer. The outer end of shaft 21 projects through a hole in wall 33 into the timer casing and such end, of itself, forms a cam for operating the breaker points 39 and 40,-being cut away, as at 38, to allow these points to close and the uncut peripheral portion holding the points open. The point 40 is adjustably secured and electrically grounded to the wall 33 of the timer case. The point 39 is mounted on a rocker arm 4|, made of insulating material and pivoted at a point intermediate its ends on a stud 42 secured to wall 33. One end of this arm 4| rides on the cam end of shaft 21. A spring 43 serves to hold the last named end of arm 4| against the cam end of shaft 21 and also serves to electrically connect point 39 to a terminal 44. The described wire 25 enters the timer case through a hole 45 and is secured to terminal 44. A condenser, indicated at 46 in Fig. l, is housed in a block of molded insulating material. I This block is secured by screws 46 to wall 33 of the timer case and has an extension which carries the terminal 44. The terminals of the condenser are not shown herein but it will be understood that they are connected in the usual and known manner, one to the ground and one to terminal 44. The timer mechanism operates to keep the circuit of the primary coil 16 open for the greater part of each revolution of the magnetic rotor, whereby flux can readily build up in the described magnetic circuit. The surface 38 of shaft 21, once during each revolution, allows the breaker points to close momentarily and then to open again. The points close just before the rotor breaks the magnetic circuit described and open at the time such break occurs.

The timer case has an opening 50 in its wall 33, enabling communication with the bottomof chamber l3 and from the bottom of this chamber a passage 5| extends downwardly and outwardly to the atmosphere. Passage 5| serves to vent the interior of the magneto. It also-serves as a drain for the removal of any water and oil that may reach the chamber l3 or timer case. While provision is made for excluding oil from the chamber l3 and timer case and none ordinarily should reach these parts, the drain serves as insurance against trouble from oil should leakage occur from any cause.

The rotor, when turned a little more than 90 degrees from the illustrated position, will es-- tablish a magnetic circuit from the magnets 28 through pole shoes 29, pole pieces l4, and core IS in one direction. When moved a little more than 2'70 degrees from the illustrated position, the rotor will be positioned to break this circuit and it is this magnetic break that is utilized to produce the spark current. The break which occurs after the rotor has moved 90 degrees from the illustrated position, is not utilized for the production of a spark in this case. Just prior to this first-named magnetic break, the breaker points 39 and 40 engage and close the primary circuit. The flux established in core I4- is thus held against substantial change while the rotor moves into position to create an effective gap between the trailing end of each shoe 29 and the adjacent end of its pole pieces I 4. At this time, the leading end of each-pole shoe has reached the opposite pole piece so that a reversal of flux in the magnetic circuit occurs, when the breaker points open. The described arrangement is not novel and is not in any way an important feature of the invention. Other arrangements may equally well be used. l

The magneto described is given as an illustrative example of one of many suitable types with which the invention may be used; The inven tion is largely independent of the type of magneto employed and the details, above described, are not to be taken as setting up limitations.

The invention is primarily concerned with the mounting of the magneto and its rotor shaft 21 and with the lubrication of the moving parts. The shaft 21 is supported by a pair of axially spaced anti-friction bearings, such as the ball bearings shown in Fig. 1. These bearings, which constitute the sole support for the shaft, are contained within a cylindrical sleeve 52 located in the passage H, above described. ,lntegrai with this sleeve is a mounting flange 53, adapted to be suitably secured, as by the cap screws 54, to a portion of the crankcase c of the engine which the magneto is intended to serve. The, flange 53 has a finished cylindrical portion-55m, fit into thecylindrical opening 0 of the crankcase as a pilot and definitely locate and center the shaft 2! with respect to the gear g of-the engine,which gear is located withinthe crankcase and serves to drive shaft.2'|. Agasket 56 seals the joint between the flange 53 and the mating flange of the crankcase. The flange 53 and sleeve 52 .in this case are made of castiron and are secured to casing ID by cap screws 53' (Figs. 1 and 4). They are, of course, virtually a part of easing l0, since theyarefixed thereto. Their construction as a separate piece is not therefore a necessity.

The ball bearings are of usualform- Their outer and inner races are marked 51 and 58, respectively, and the intervening series of balls 59. The inner races 58 are spaced apart by a sleeve 60 on shaft 21 and the right-hand inner race abuts a shoulder 6| on the shaft. Keyed to shaft 21 is a hub 62, located to the left of the left-hand inner race. The left-handor inner end of shaft 21, which extends into the crankcase, is threaded to receive a nut 63 and between this nut and hub 62 are a washer 64 and a sleeve 55: gether the sleeve 65, hub 62, both inner races 58 and the intervening spacer sleeve 60. The

outer races 51 are held in place by split retainer annular flange. 69 on the hub '62, which constitutes the driven member. The ends of the spring 68 are connected, as shown in Fig. 5, to the members 61 and 69. The member 62 has a flange 10 (Fig. 2) provided with a shoulder H, against which a pin 12 fixed to the gear 61 is normally held engaged by the spring 68. The flange 62 has pivoted thereto at 13 a member which partially.

surrounds hub 62, and one end of which forms a latch arm :74 adapted, when shaft 21 is rotat- This nut, through the washer, clamps toing very slowly to engage a stationary abutment in the form of a stud 15 (Figs. 3 and 4) fixed to flange 53, and to thereby temporarily stop the rotation of hub 62. The longer arm I6 of this member constitutes a weight adapted, at higher speeds of rotation of shaft 21, to swing outwardly by the actionof centrifugal force and move the latch arm 14 inwardly so that it cannot engage abutment 15.- Stops 11 and 18 on arms I4 and 15, respectively, are adapted by abutment with the periphery of hub 62 to limit inward and outward movement of the latch arm and the outward and inward movement of the weight arm, respectively. The free end 19 of the weight arm is adapted to be engaged and moved by the pin I2 to release the latch arm 14 from abutment 15. Thus, after latch arm 14 has engaged abutment I and arrested the hub 62 and shaft 21, the gear 81 and its pin 12 continue to move in the illustrated direction, winding up spring 68, and the pin eventually reaches the position shown in Fig. 4, wherein it has engaged the end 19 of weight arm 16. Continued movement of pin 12 will move arms 16 and I4 and release the latter from abutment 15, whereupon the spring 68 will draw the hub 52 and shaft 21 suddenly forward until the shoulder H on the hub again abuts pin 12.

. The lubrication of all moving parts of the magneto is accomplished entirely by oil received from the crankcase c. The oil splash therein lubricates the driving gears and all parts of the impulse driving mechanism and in addition the two sets of ball bearings which form the only ones used for supporting the rotor shaft 21. A hole 80 leads from the outer and uppermost part of sleeve 52, at its intersection with flange 53, inwardly and downwardly through the sleeve into the interior thereof at a'location between the two bearings. This hole receives oil from the crankcase by splash, or in any other suitable way, and such oil is conducted into the sleeve 52 to lubricate both bearings. Excess lubricant drains back into the crankcase through a hole 8|, extending through the sleeve from the lowest part or its interior and leading downwardly into the interior of flange 55, whence it can flow into the crankcase. A suitable sealing means is provided to restrain oil which passes the right-hand or outer bearing from reaching the chamber l3. In this case, the sealing means comprises a rawhide disk 82 secured ina metal cup 83 between the circular face thereof and an annular ring 84 of metal,

being held in place by crimping the open end of the cup inwardly upon the ring 84. The cup '83 tightly fits in the inner end of passage I l and.

things, by a direct mounting of the magnetohousing on the crankcase, without intervening brackets or mounting bases, and by a mounting of the rotor in the housing in such a manner that all of the rotor bearings are placed in communication with the crankcase to be automatically lubricated therefrom. By simply bolting the mounting flange 53 to the crankcase (after the gear 61 has been properly meshed with the engine driven gear g to secure the proper timing of ignition for the engine) the problem of lubricating the magneto is solved once and for all. The bearings are partitioned off from the rotor by the sealing device 82 and they are located near the mounting flange where they may at all times communicate with the crankcase and receive lubricant therefrom. The bearings are virtually put into the crankcase by the special mounting described. And there are no other parts of the magneto which require lubrication-- the timer cam being a fixed part of the rotor shaft and requiring no separate bearing. Thus, the-user of the engine need give no attention to the magneto, so far as lubrication is concerned and, so long as he supplies oil to the engine, the magneto parts will be properly lubricated. This arrangement is of great practical importance because it affords excellent assurance that the magneto parts will be properly lubricated without requiring separate attention. An engine operator will rarely neglect to keep the crankcase of his engine supplied with the proper amount of oil but he might easily neglect to oil the magneto. Thus, the present arrangement guards against this possible neglect of duty by the operator and insures that the magneto will be properly lubricated to give the intended long and satisfactory service.

It should also be noted that the magneto bearings are eifectively protected from dust and dirt just as much as the engine bearings in the crankcase are. It is necessary to ventilate the magneto in some way and the ventilation provisions offer a possible source for dust and dirt to reach the bearings of the ordinary magneto. But here the magneto bearings are separated from the magneto structure and sealed off by the means 82 from that part of the magneto housing that is ventilated.

. The ventilation provision-the hole 5Iis of novel form and thought to be important. The hole is made of relatively great length, and preferably inclined to the horizontal, to secure a leisurely entrance of air as distinguished from the more forcible blowing in of air which may occur with the usual forms of ventilation holes, where the length of the hole is seldom greater and often less than the diameter thereof. A current of air passing beneath the magneto housing cannot readily enter into the magneto under any appreciable pressure and thus dust and dirt are not forced or blown in. Some dust and dirt will naturally enter the hole 51 but much of it will tend to cling to the wall of the hole because of the lack of pressure in the entering air and such dust and dirt as does enter the housing will not be forced against the magneto parts,such for example as the parts of the timer,but will be gently deposited in the housing in out of the way locations, where it will do no harm.

The invention thus affords improvements in magneto structure which are calculated to protect the moving parts of the magneto against damage from lack of lubrication and from dust and dirt. The bearing arrangement and the mounting provisions have been incorporated in a simple and practically fool-proof structure capable of manufacture at low cost and yet exceedingly effective and calculated to give a long useful life without requiring any attention on the part of the operator.

What we claim is:

1. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein and a shaft to which said rotor is fixed, said housing having a flange secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, and bearing means for rotatably vsupporting said rotor shaft and constituting the sole support for said shaft, said bearing means located in said housing between the rotor and said flange, said housing having passages leading from the crankcase side of said flange to said bearing means and from the latter back to said side of said flange for the circulation of lubricant from the crankcase to said means.

2. The combination with the crankcase of an engine and an engine driven gear rotatable therein, said crankcase having an opening adjacent said gear, of a magneto including a housing, a rotor and a stator mounted therein, and a shaft to which said rotor is fixed, said housing having a flange secured to the crankcase and closing said opening, said shaft extending out of the housing through said flange and projecting beyond the flange into said crankcase, a gear on the projecting end of said shaft for driving engagement with the first-named gear, impulse driving mechanism for actuating said shaft from said gear and located between the gear and flange in position to be lubricated from the splash in the crankcase, bearing means in said housing for rotatably supporting said shaft and constituting the sole support therefor, said housing having passages leading from the crankcase side of said flange to the bearing means for supplying lubricant from the crankcase thereto and other passages leading from the bearing means to said side of said flange for returning lubricant to the crankcase.

3. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein, breaker point mechanism including an actuating cam, and a shaft to which said rotor and cam are fixed, said housing having a flange secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, and bearing means for rotatably supporting said rotor shaft and constituting the sole support for said shaft, said bearing means located in said housing between the rotor and said flange, said housing having passages leading from the crankcase side of said flange to said bearing means and from the latter back to said side of said flange for the circulation of lubricant from the crankcase to said means.

4. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein and a horizontal shaft to which said rotor is,

fixed, said housing having a flange disposed at right angles to the axis of said shaft and secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, said housing having a recess therein coaxial with said shaft and extending inwardly from the crankcase side of said flange to the rotor axially spaced bearings one near said flange and one near the rotor mounted in said recess and rotatably supporting said shaft and constituting the sole bearing means therefor, sealing means located between the rotor and the adjacent bearing to restrain the passage of lubricant from said recess to the rotor, said housing having a lubricant feed passage extending from the crankcase side of said flange in downwardly sloping relation to said recess at a point intermediate said bearings, said housing also having a lubricant drain passage extending from said recess-at a point intermediate said bearings in downwardly sloping relation to and opening through the crankcase side of said flange.

5. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, arotor and a stator mounted therein and a horizontal shaft to which said rotor is fixed, said housing having a flange disposed at right angles to the axis of said shaft and secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, said housing having a recess therein coaxial with said shaft and extending inwardly from the crankcase side of said flange to the rotor, axially spaced bearings one near said flange and one near the rotor mounted in said recess and rotatably supporting said shaft and constituting the sole bearing means therefor, sealing means located between the rotor and the adjacent bearing to restrain the passage of lubricant from said recess to the rotor, said housing having a lubricant feed passage extending from the crankcase side of said flange in downwardly sloping relation to said recess at a point intermediate said bearings, said housing also having a lubricant drain passage extending from said recess at a point intermediate said hearings in downwardly sloping relation to and opening through the crankcase side of said flange, said housing having a second lubricant drain passage leading from the space between the sealing means and the adjacent bearing and opening through the crankcase side of said flange.

6. In a magneto, a housing, a stator and a rotor mounted therein, a shaft fixed to the rotor, said housing having a recess coaxial with said shaft and extending from one outer face inwardly toward the rotor; sealing means closing the inner end of said recess except for an opening throu h which the shaft passes, a mounting flange disposed at right angles to the axis of said shaft and adapted to be secured to the crankcase of an engine, said flange having an integral sleeve fitting into said recess and fixed to said housing, said shaft extending through said sleeve in spaced and coaxial relation and beyond the flange, axially spaced bearings mounted in said sleeve and forming the sole means for rotatably supporting said shaft, said housing having lubricant conducting passages extending from the flange to said bearings.

7. In a magneto, a housing, a stator and a rotor mounted therein, a shaft fixed to the rotor, said housing having a recess coaxial with said shaft and extending from one outer face inwardly toward the rotor, sealing means closing I the inner end of said recess except for an opening through which the shaft passes, a mounting flange disposed at right angles to the axis of said shaft and adapted to be secured to the crankcase of an engine, said shaft extending through said recess in coaxial relation and beyond said flange, bearings for said shaft all mounted in said recess, said housing having on one side of said sealing means lubricant conducting passages extending from the flange to the bearings and having on the other side a relatively long and downwardly sloping ventilation and drain passage connecting its interior to the atmosphere.

8. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein and a shaft to which said rotor is flxed, said housing having a flange secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, and bearing means for rotatably supporting said rotor shaft and constituting the sole support for said shaft, said bearing means located in said housing between said flange and the point of connection of the rotor to said shaft, said housing having a passage leading from the crankcase side of said flange to said bearing means for the supply of lubricant from the crankcase to said means.

9. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein, breaker point mechanism including an actuating cam, and a shaft to which said rotor and cam are fixed, said housing having a flange secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection between said shaft and member, and bearing means for rotatably supporting said rotor shaft and constituting the sole support for said shaft, said bearing means located in said housing between said flange and the point of connection of the rotor to said shaft, said housing having a passage leading from the crankcase side of said flange to said bearingmeans for the supply of lubricant from the crankcase to said means.

10. The combination with the crankcase of an engine and an engine-driven member rotatable therein, said crankcase having an opening adjacent said member, of a magneto including a housing, a rotor and a stator mounted therein and a horizontal shaft to which said rotor is fixed, said housing having a flange disposed at right angles to the axis of said shaft and secured to said crankcase and closing said opening, said shaft extending out of the housing through said flange and into the crankcase, a driving connection'between said shaft and member, said housing having a recess therein coaxial with said shaft and extending inwardly from the crankcase side of said flange to the point of attachment to the rotor to said shaft, axially spaced bearings one near said flange and one near said point mounted in said recess and rotatably supporting said shaft and constituting the sole bearing means therefor, sealing means located between the rotor and the adjacent bearing to restrain the passage of lubricant from said recess to the rotor, said housing having a lubricant feed passage extending from the crankcase side of said flange in downwardly sloping relation to said recess at a point intermediate said bearings.

11. In a magneto, a housing, a stator and a rotor mounted therein, a shaft fixed to the rotor, said housing having a recess coaxial with said shaft and extending from one outer face inwardly toward the rotor, sealing means closing the inner end of said recess except for an opening through which the shaft passes, a mounting flange disposed at right angles to the axis of said shaft and adapted to be secured to the crankcase of an engine, said flange having an integral sleeve fitting into said recess and flxed to said housing, said shaft extending through said sleeve in spaced and coaxial relation and beyond the flange, axially spaced bearings mounted in said sleeve and forming the sole means for rotatably supporting said shaft, said housing having a lubricant conducting passage extending from the flange to said bearings. 1

WILLIAM F. BORGERD. WILLIAM o'rro BECHMAN. KENNETH A. HARMON.

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