US2475843A - Means operated by a starter generator for cooling a gas engine - Google Patents

Description

July 12, 1949. F. M. JONES 2,475,843

MEANS OPERATED BY STARTER GENERATORS FOR COOLING GAS ENGINES Original Filed Oct. 26', 1944 3 Sheets-Sheetl INVENTOR. FREDERICK M JOES y 1949- F. M. JONES 2,475,843

MEANS OPERATED BY STARTER GENERATORS FOR COOLING GAS ENGINES Original Filed Oct. 26, 1944 3 Sheets-Sheet 2 JNVENTOR. FRED RICK M. JONES FIG. 3. my

' ATTORNEY July 12, 1949. F. M. JONES MEANS OPERATED BY STARTER GENERATORS FOR COOLING GAS ENGINES Original Filed 001:. 26, 1944 3 Sheets-Sheet 3 INVENTOR. FFE E M. JONES Y/ w h/ 5 ATTO RNE1 Patented July 12, 1949 UNITED STATES PATENT OFFICE MEANS OPERATED BY A STARTER GENERA- TOR FOR COOLING A GAS ENGINE nesota Original application October 26,

6 Claims. 1

My invention relates to means operated by a starter generator for cooling it and a gas engine, and has for its object to provide in combination a starter generator directly attached to the front of the gas engine and operatively connected with the motor shaft thereof, wherein the armature is caused to rotate in relation to the field members, together with means operatively connected with said armature in conjunction with air passages extending past the rotating armature and about the cylinder or cylinders of thegas engine to effect the cooling thereof,

The usual practice heretofore has been to rotate the armature within the magnetic field. That is, to have the windings and poles of the magnetic field stationary and external to the armature and to rotate the armature in the form of a laminated cylinder within the field coils and windings positioned as in a hollow shell. This has necessitated objectionable wide spacing of the pole pieces and rotating the armature at such high speed that even though the commutator is reduced in diameter, the actual fiow of current impulses thereto and therethrough 1s less than would be expected. Furthermore, the small size of the armature necessary within the members of the magnetic field makes it rather ineffective as an inertia fly-wheel.

I have discovered that an arrangement of the field poles and windings in the form of a cylinder of relatively small diameter held stationary at the center of a generator and of the armature in the form of a hollow shell which rotates with its connected commutator about the field poles and field windings, produces a much more efficient generator of electric current generated or required for the starter and one which may function as a perfectly combined inertial fiywheel and blower positioned directly upon the gas engine motor shaft so at the same time to provide the required inertia power to absorb the inertia losses from reversals of movement of the gas engine pistons and to produce a strong current of air to pass over and among the radiator fins of an air-cooled gas engine and thus to cool the same. I also discovered that this air current has the important ffect of cooling the enerator itself and thus preserving the insulation.

It is a principal object of my invention, therefore, to arrange the field poles and windings of a generator in the form of a cylinder held stationary at the center of a generator with an opening through the center thereof for the reception of an extension of the gas engine motor shaft andto arrange the armature in the form 1944, Serial No.

Divided and this application October Serial No. 621,341

of a hollow shell directly connected to the motor shaft and rotated by it about the field poles and windings, and to use the rotating armature as a means for operating blower means to cool the gas engine and the generator.

It is a further object of my invention to form upon the outer periphery of the armature framework a circumferentially arranged series of blower fan blades, and to arrange them withina shroud about air cooling radiator fins on the motor cylinder, so the operation of the generator itself will cause currents of air to move within the shroud and through the radiator fins and about all parts of the generator to cool it and the motor.

It is a further object of my invention to so position the generator in relation to the shroud that the blower blades operated by the rotating armature will be positioned to rotate centrally as to a multiple cylinder gas engine, as for example a two-cylinder gas engine, and the air currents generated by said fan blades will be distributed under the shroud so as to pass under and about the radiator fins on both said cylinders and discharge with the heat removed vertically upward.

A further object of the invention is to provide a multiple purpose machine which includes an engine of air cooled type having its driven shaft extending from opposite sides of the engine with a power take-off connected to one end of the shaft and a starter generator connected to the other end of the shaft for starting the engine and thereafter to become an electric power plant, together with means operated by the starter generator for cooling the engine.

The full objects and advantages of my invention will be pointed out in detail and the different relationships of the parts will be clearly indicated in the following specification, and the novel features individually in making up new combinations and such combinations by which the aforementioned advantageous results are secured, will be particularly pointed out in their cooperating arrangement in the appended claims.

This application is a division of my pending application, Serial No. 560,454, filed October 26, 1944.

In the drawings illustrating an application of my invention in one of its forms:

Fig. 1 is a front elevation view of my armature blower mechanism as it would appear in position assembled upon the front end of a crankshaft of a gas engine with the shroud and motor parts omitted.

acrasas 1'18. 2 is a rear elevation view of an entire twocylinder motor assemblage similar to the showing of Fig. 1 and showing the relation of all of the rts. Fig. 3 is a longitudinal sectional elevation view of the starter generator and the fan blades attached to the rotating armature taken on line 3-3 of Fi 1.

Fig. 4 is a side elevation view of the engine and starter generator assembly with some parts broken away and others shown in section.

Fig. 5 is a side elevation view on. a reduced scale of a gas engine having my generator and blower mechanism attached thereto with some parts broken away.

Fig. 6 is a top plan view of a two-cylinder gas engine showing the arrangement of the shroud as to both said cylinders and the top openings for escape of air after it has passed about the fins of said cylinders of the gas engine.

A base plate 10, Figs. 3 and 5, is shown bolted directly to the face of a two-cylinder gas engine I i. To this base plate is secured by a multiplicity of bolts i3, as shown in Fig. 3, a pole piece designated generally by the numeral l4. The bolts i3 have their heads l5 countersunk in the outer face of the pole piece l4 and are screwed into internally threaded bosses l6, Fig. 3.

The baseplate i0 is circular in outline and is formed with an outwardly turned boss 1! which surrounds a bearing (not shown) that extends into a central circular opening l8 through the base plate 10. A corresponding opening is is formed in the pole piece 14. The pole piece is provided with an annular groove 26 forming a lip 2i which overlies the inner edge 22 of the boss l1, and is spaced a suitable distance therefrom. The field windings 23, of known arrangement, are contained in annular channels 24 formed in the mass of the pole piece, as indicated in Fig. 3. The pole piece M has its outer portions fall in a cylindrical surface 25.

The engine shaft l2 extends through opening i8 and has a portion 2'! in the form of the frustum of a cone, with a cylindrical threaded extension, indicated in dotted lines in Fig. 3 at 28. Upon this conical extension 21 of shaft l2 there is adapted to seat an internal conical opening 29 corresponding in size and shape with the conical frustum 21, formed in a tubular frame extension 33 of a frame plate or head 36.

The extension 33 is formed with an annular ledge 30. The ledge 30 is engaged by the lower edge iii of a nut 32 threaded upon the threaded extension 28 by which the tubular member 33 has its conical seat 29 forced upon the conical portion 21 of shaft i2. A pair of splines indicated in dotted lines at 35, Fig. 3, firmly holds tubular extension 33 for rotation with shaft i2. The nut 32 is countersunk at 36 into the opening leading through tubular extension 33. The nut is locked against turning by a washer 3! and a lock ring 38 snapped into an internal groove 33a formed in the inner body of tubular extension 33, Fig. 3.

The frame or head 34 is formed with an annular flange 39 having a sloping outer wall 40. To the flange 39 is secured b a multiplicity of screw bolts 4| a blower ring 42 and an armature designated generally by the numeral 43. The commutator 44 is a tubular member of standard construction which is held by being placed on the extension member 33 of head plate 34, and is additionally held thereto by screws, one of which is shown at 45 in Fig. 3,'and which i. 4 are countersunk in the head plate 34, and which extend into segments insulated from the contact body of the commutator.

The windings of the armature and of the insulation, as shown, are of standard construction and need not be described in this application.

The frame head 34 is thus held for rotation with and .by the shaft l2. Hence, the armature 43 is firmly held tQ'IOtflte about the several pole pieces 24 and the commutator is held to rotate with the armature. This is also true of the blower ring 42 which is held to the armature by the bolts 4| and rotates with it.

Upon the blower ring 42 is secured a multiplicity of curved blower vanes 43, extending radially about the shaft 12, as shown in Figs. 1, 3. 4 and 5. The vanes are also shown in dotted lines in Fig. 2 and in relation to the enclosing shroud in Figs. 4 and 6. The vanes 43 are thus held for rotation with the blower ring 42 and the armature and connected parts.

My invention is shown applied to a two cylinder gas engine having a pair of opposed cylinders 41, 48. The crankshaft I2 extends through the front and rear facesof the engine as shown in Figs. 2, 4, and 5. On the rear of the engine as it is normally used, a power transmitting means in the form here shown is a pulley 33 secured to the rear end of crankshaft i2 for driving any form of a main load for which the engine is intended. The starter generator discussed in detail heretofore is mounted on what may be regarded as the front of the engine as it is normally used, and its operative portions are connected to the front end of the crankshaft 12 as shown in Fig. 3. This arrangement affords two distinct advantages. Primarily the starter generator is used initiallyto crank the engine and thereafter is used to generate electric power which may be stored in a battery that supplies the source of power for the starting operation, or the current may be used in any one of a number of other ways, such as power for the ignition of the fuel. Secondly, its rotatable portions act as a flywheel to stabilize the operation of the crankshaft, and also to counterbalance the torque of the main load which is connected to the other end of the crankshaft. Thirdly, by being positioned on the end of the crankshaft opposite the main load driving means, the overall dimensions of the engine and starter generator are materially reduced. This arrangement minimizes bearing wear and the use of elongated bearings as in the instance where the starter generator was positioned on the same side of the engine as the power transmitting means and between said means and the engine, which was the prior art construction of machines of this type. Furthermore, the blower vanes 46 by being mounted on the periphery of the starter generator form a highly effective means of supplying a large volume of air for cooling the eng me.

It follows that in order to carry the air to these two cylinders for cooling them a shroud should be so formed as to provide a chamber open at its outer end and otherwise enclosing and surrounding the blower vanes, and which encloses the two engine cylinders and will lead the air to move about the cooling fins on the engine cylinders and to discharge to atmosphere through separate openings over each cylinder.

This shroud is designated generally by the numeral 49. It comprises a roughly oval-shaped casing 50 secured to the engine frame by bolts This casing is formed at its front with a flaring. lip 52 surrounding a circular opening 53 which immediately surrounds the blower ring 42 and blades 46, being spaced 3. sufllcient distance from the edges of the blades at their closest points to the shroud portions 50 to prevent contact between the blades and the shroud, as shown in Fig. 4.

From the opening 53'the shroud has a portion 54 which spreads to the sides of the engine cylinders 41 and 48 and forms a chamber 55 which opens into a passageway 59 underlying at each side the engine cylinders 41 and 48.

The engine cylinders are provided with a multiplicity of heat-radiating fins 56 which extend entirely around the cylinders and which advantageously are curved, as indicated at 51 in Figs. 4 and 5. In the top of the shroud is .an opening at each sid above the respective engine cylinders 4'1 and 48, as indicated at 58 in Fig. 6.

In operation the starter generator has a primary function of starting the engine, and thereafter it becomes operative to generate electric power which is used to ignite fuel burned in the engine, and also to charge a battery (not shown) which is used to supply power for the starting operation. The circuit by which th electric current is conveyed for these purposes is disclosed in Numero and Jones Patent 2,337,164, dated December 21, 1943, and assigned to the assignee of this application. After the engine has been started and is self-operating, the starter generator becomes in addition to a source of electric power, an inertia flywheel to stabilize the operation of th engine crankshaft and also to counter-balance the main load being driven by the power transmitting means 60. By being positioned on an opposite side of the engine from the power transmitting means (ill, the over-all dimensions of the machine are materially reduced and other troublesome features are minimized. This is important, because in the prior art starter through the metal elements to the several vanes making up the blower and since these vanes are brought into contact with the large volume of air travelling through the shroud, the vanes will transfer the heat of the generator to the air column.

The advantages of my invention are clearly apparent from the description in the foregoing specification. With little consumption of power over that normally employed to rotate the armature and commutator an exceptionally eflicient blower which is relatively large in diameter operates to pass air in large volumes about and between ,the cooling vanes on a two-cycle gas engine.

The fan or blower is devoid of operating connections. It is simply an outer adjunct of the armature inertia flywheel, and because of its generators such as is disclosed in Patent 2,33'7,-

164, the starter generator and the power takeofi are on the same end of the engine, and in addition to making a. longer structure as measured along the axis of the crankshaft, also tended to create an unbalanced condition on the outer end of the driven shaft which carried both the power take-off and the starter generator, and caused considerable bearing difliculties. Furthermore, in the arrangement forming the present invention, the starter generator carries the blower vanes 46, which are effective as a means of cooling the engine, where the same is of aircooled type. By virtue of the fact that the starter generator is secured to the front end of the engine, as distinguished from the rear end where the power take-off is located, it is capable of delivering air in a short unobstructed path to the engine and is therefore an improved means of cooling the engine.

One of the principal advantages of the present invention resides in its compactness which enables it to be mounted within a device where space is extremely limited. The dimensions of the combined engine and generator when taken along the axis of shaft I2 is about one-third of the dimension when taken on a plane transverse to the axis of the shaft when the shroud is included.

Another advantage resides in the manner of dissipating the heat created in the generator. As most of the heat comes from the armature it will be noted that this heat may be conducted diameter, large relative to the size of the gas engine cylinders, the large volume of air is not only easily gathered and forwarded, but it is distributed over the armature and commutator and about the gas engine cylinders and the cooling fins thereon with not only exceptionally large heat exchange contact, but also with remarkable uniformity both in that contact and in the operative effect of taking the heat from the engine.

A particularly'useful advantage comes from the fact that the large volume of air introduced by the fan arrangement flows about the generator itself and all parts thereof. This effects in a remarkable degree a. cooling of the generator itself and all of its parts and particularly the insulation, which in present practice often is injured or destroyed by excessive heat.

Iclaim:

1. In combination with an air-cooled engine and its main driving shaft, a flat base plate adapted to be bolted directly to the face of the engine, said plate having a central opening closely surrounding the driving shaft, .a cylindrical field pole piece rigidly secured on one side to the base plate, said pole piece having a central opening forming an extension of the opening in the base plate into which the end of the driving shaft extends, a flat outer plate member parallel with the base plate and having a circular flange turned inwardly at its outer edges to surround the pole piece and forming an enclosure on the side of the pole piece opposite the engine, an armature rigidly bolted within the interior of said member for rotation with respect to the pole piece, fastening means passing through the outer surface of said'member at a central portion thereof for securing said member to the outer end of the driving shaft whereby said member and its connected armature rotate in unison with the driving shaft, a plurality of curved vanes mounted on each quadrant section of the outer surface of the flanged portion of said member, said vanes being adapted to direct the flow of a large body of air in the direction of the engine when said plate member is rotated, and a shroud which closely encloses the engine and the generator and forms an air channel to and about the engine, said shroud having a first opening in alignment with the outer side of the plate member for admitting air into the shroud and in contact with the vanes, said shroud having a second opening over the top of the engine for egress of air after the same has been in contact with the engine.

2. In combination with an air-cooled engine and its main driving shaft, a threaded connecting portion at the outer end of said shaft, 3

s am starter generator comprising a field pole piece of circular outline having a plurality of field windings adjacent its periphery, means for rigidly securing said pole piece directly on one face of the engine, said pole piece having a central opening into which the outer end of the driving shaft extends, a fiat outer plate member having a circular flange turned inwardly at its outer edges to surround the pole piece and forming an enclosure on the side of the pole piece opposite the engine, an armature rigidly bolted within the interior of said member for rotation with respect to the pole piece, said outer plate member having a central opening in alignment with the end of the driving shaft, a threaded connector adapted for entry through the opening in said plate member for securing said member to the outer end of the driving shaft in such a manner that the plate member rotates in unison with the driving shaft, a plurality of arcuately shaped vanes mounted on each quadrant section of the outer surface of the flange portion of said member, said vanes being adapted to direct the fiow of a large body of air in the direction of the engine when said plate member is rotated, and a shroud which closely encloses the engine and the generator and forms an air channel extending to and about the engine for directing air into contact with said vanes and directing the air delivered by said vanes into contact with the engine.

3. In combination with an air-cooled engine having a, driven shaft, a flat plate member adapted to be bolted directly to a face of the engine, said plate member having a central opening closely surrounding the driven shaft, a cylindrical pole piece rigidly secured on one lateral surface to said plate member in such a manner as to render the pole piece stationary, said pole piece having an opening extending through its central axis to provide entry for said driven shaft, a fiat circular plate member positioned on the opposite lateral side of the pole piece and forming an enclosure about the side of the pole piece opposite the engine and parallel to the first named plate member, said second named plate member having a central tubular projection which extends into the central opening of the pole piece and surrounds the outer end of the driven shaft, said projection having an opening therein, said plate member having an inwardly extending peripheral flange surrounding the outer limits of the pole piece, an armature carried on the peripheral flange and surrounding the pole piece, a connector for, entry through the opening in the central projection for securing said plate member to the outer end of the driven shaft in such a manner that the plate member rotates in unison with the driven shaft, a plurality of arcuately shaped vanes mounted on each quadrant section of said flange, and a shroud which closely encloses the engine and the vanes, said shroud having a first opening in alignment with the outer side of the second named plate member for admitting air into the shroud and in contact with said vanes, said shroud having a second opening over the top of the engine for egress of air after the same has been in contact with the engine.

4. A compact multiple purpose machine, including in combination, an engine of air-cooled type, a crankshaft within said engine and having its opposite ends extending outwardly from opposite sides of the engine, power transmitting means connecting with a first end of the crank- I 8 shaft and at the rear of the engine and adapted to drive a load, a fiat plate adapted to be bolted to the front face of the engine, a starter generator positioned on the front of the engine for initially starting the engine and generating elecabout the engine, and a series of fan blades positioned within the shroud and extending about the periphery of the starter generator for drawing air into the shroud and blowing the same over the engine when the latter is self-operating, said fan blades and the rotatable portion of the starter generator being conjointly connected to the second end of said crankshaft and forming a unitary inertia element for stabilizing the crankshaft and counter-balancing the load on the first end of the crankshaft.

5. A compact multiple purpose machine, including in combination, an engine of air-cooled type, a crankshaft within said engine and having its opposite ends extending outwardly from opposite sides of the engine, power transmitting means connected to a first end of said crankshaft and adapted to drive a main load, a flat annular member secured to the opposite side of the engine, a starter generator positioned on the opposite side of the engine from the power transmitting means for initially starting the engine and generating electric power when the engine is self-operating, said starter generator comprising a stationary field pole piece and a rotatable armature, fastening means for securing the field pole piece to the outer surface of the fiat annular member, a second fiat annular member having a peripheral flange which extends beyond the outer limits of the pole piece and forms an outer enclosure about the pole piece on-the side opposite the engine, a multi plicity of vanes secured to the peripheral flange of said second member, fastening means for securing the armature within the interior of said second member for rotation with respect to the pole piece, fastening means for securing said second member to the second end of the crankshaft whereby said second member and the armature form an inertia flywheel to stabilize the crankshaft and counter-balance the load on the first end of the crankshaft, and a shroud for surrounding the vanes on said second member and forming an air channel for directing air in and about the engine to cool the same when the engine is driving said second member.

6. A compact multiple purpose machine, including in combination, an engine of air-cooled type, a crankshaft within said engine and having its opposite ends extending outwardly on either side of the engine, power transmitting means connected to a first end of said shaft and adapted to drive a main load, a starter generator positioned on the opposite side of the engine from the power transmitting means and adapted to initially start the engine and thereafter to generate electric power when the. engine is selfoperating, said starter generator comprising a stationary portion and a rotatable portion, and a series of fan blades extending about the periphery of the starter generator for blowing air over the engine to cool the same when the engine is self-operating, said fan blades and the rotatable portion of the starter generator being con- FREDERICK M. JONES.

REFERENfiES CITED The following referenlces are of record m the file of this patent:

UNITED STATES PATENTS Number Re. 23,000 979,003

Name Date Jones May 11, 1948 Heany Dec. 20, 1910 Number 10 Name Date Heany Nov. 17, 1914 Hassler Feb. 15, 1916 Kouyoumjian Mar. 29, 1917 Kouyoumjian Mar. 20, 1917 Andrews et; a1. Mar. 6, 1923 Burchett Jan. 13, 1925 Andrews et a1. Nov. 23, 1926 Tingley Nov, 28, 1933 Chilton Feb. 27, 1934 Heintz May 15, 1934 Else Sept. 8, 1936 Ballen'tine Feb. 23, 1937 Sutherland July 30, 1940

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