US1805875A - Rotary engine - Google Patents

Description

May 19, 1931. VN. D. LEV!N 1,805,875

ROTARY ENGINE Original Filed Feb 13, 1917 2 Sheets-Sheet 1 I O J .3

Patented May 19, 1931 l UN rED. stares te eFFwx NlfLS D. LEVIN, F GOLUIVIBUSQOHIO, ASSIGNQR TO THE JEFFREY MANUFACTURING COMPANY, or constra ns, onto, A eenroaarrcn' or onIo ROTARY ENGINE Application filed February 13, 1917', Serial E'o. 453,715. Renewed March 19, 1921;

This invention relates to certain newv and useful improvements in rotary enginesand especially to that class of engine in which .a pair ofparallel rotors having inter-meshlng tooth blades are mounted ina casing the walls of which cooperate to confine the actuating fluid to the spacesbetween the blades of the rotors.

tinued rotation after the supply The especial object is to provide an engine of the class described, of high efficiency, great durability, and extreme compactness ofdesign, which shall be especially adapted to use under the exacting conditions obtained in machines for mining coal. V

.Another object is to provide improved mcthod of constructing the rotors andof mounting the same in the engine casing. Another object is to provide means to prevent-the formation ofa vacuumon the admission side of the rotors during their. conof actuating fluid has been shut off. 7 I

These and other objects will appear in the following specification wherein is disclosed disclosed in Fig. 1.

Fig. 3 is a transverse SQCblOIl along the line 33 of Fig. 2. I

Fig. 4: is a transverse section alongthe line 44 of Fig. 1.

I Fig. 5 is an elevation oftheforward end of the en ine illustrated in Fig. 1. 1

Fig. 6 is a plan view, partly in sectlon, offa modified form of my invention, the upper portion of the casing being broken away to reveal the interior parts of the engine. 1

Like numerals refer to similar parts 1n the several figures.-

, The preferred embodiment of my inventi-on comprises a casing 37 upon which are formed lugs 38 by which it may be attached to any preferred foundation, Withinthis casin closely approaches the tops of the spiraltooth blades 41 on both sides of the central longi- Fig. 2 is a: side elevation of the machine casing is mounted a pair of similar parallel drums to their. ends and extending around a part of their circumference. Thesedrums are mounted upon parallel shafts 42 and 43 to which are clamped the inner races of the ball bearings 4C4: and-4L5 by suitable clamping members 46 and 4-7 The outer races of the.

ball bearings 44 and 45 are supported in recesses 48 and 49 of the end plates 50. and 51 secured to the casingby suitable machine screws 52 to support the rotor.

The casing 3 7 entirely encloses the rotors 39 and 40 and is provided at its upper. side with aninspection window 53 having a cover plate 54 secured in place by suitable machine screws 55. The upper portion of the casing forms an exhaust chamber 56 which receives the fully expanded actuating fluid and discharges itinto the atmospherethrough the exhaust openings 57 at either side of the The lower wall 58 ofthe casing tudinal planes of the casing for a distance equal to the'spiral advance of the tooth blades.

.i'lfhis surface 58 cooperates withthe tooth blades to form V shaped-expansion chambers ,59 adapted to receive the actuating fluid from the port 60 positioned in the central longitudinalplane of the casing. This port GOIis of such proportions that the admission of fluid to each expansion chamber is cut off bythe succeeding tooth blades as soon as said chamber has received its. initial charge. As the surface 58 extends only a dlstance equal to the spiral advance of the tooth veinctl this chambers at the instant when it is expanded tothe full effective limit. It is, therefore,

unnecessary for the end walls of ,thecasing satisfactory operation of the journal bearings and, at the same time, assist in the quick relief of the pressure in the expanslon chainfluid will be exhausted from the expansion bers. Formed in the lower wall of the casing is an admission chamber 62 communicating with the port and provided at either side of the casing with screw threaded apertures 63 and 64 into which may be fitted the supply pipe 65'through which the actuating fluid is received from the source of fluid supply. The aperture 64 on the side of the machine opposite the supply pipe 65 may be closed in, any convenient manner, as by a pipe plug 66 to prevent the escape of the actuating fluid. A suitable throttle valve may be connected in the supplypipe 65 at a point convenient to the hand of the operator, affording means to control the supply of actuating fluid to the engine. When fluid is admitted into the chamber 62 it flows through the port 60 into 'the'su'ccessive expansion chambers 59 cansing the rotors 39 and 40 to revolve in opposite directions. Vhile the engine is in operation the pressure of the air in the admission chamber 62 and in the expansion chambers 59 tends to lift the rotors 39 and 40 away from the casing surface 58 thereby preventing actual contact of the metal of the rotors with that of the casing. Should the rotation of the drums '39 and 40 be continued after the in the admission and expansion chambers thereby permitting the rotors 39 and 40 to be forced against the casing wall 58 by the atmospheric pressure, producing excessive friction between the rotor teeth 41 and the "casing wall 58 and striking sparks therefrom which escape through the exhaust openings 57. Mining machinery is often surrounded by a gaseous atmosphere adapted to ignition by such sparks and I have, therefore, provided relief devices to prevent the formation of such vacuums. Formed in the side wall of the casing is an aperture 68 communicating with the admission chamber 62, into which is fitted the relief valve 69. This relief valve comprises a metallic ring 7 O, secured to the casing by suitable machine screws 71, the inner edge of which is beveled to form the valveseat 72. Upon this valve seat 72 is fitted a valve disc 7 3' having a central stem'7 4 adapted to. longitudinal movement in a guide block 75supported centrally of the ring 70. To the outer end of the valve stem 74 is secured a a: collar 76 engaging the outward end of a comfluid from the admission chamber 62. Should the pressure within the admission chamber become less than that of the surrounding atmos. here the valve disc 73 will be pressed inwardly to allow inflow of the atmosphere to which they are controlled.

equalize the pressure thereby preventing the undesirable friction between the rotor teeth and the casing and the consequent production of'sparks.

At one end of the engine the shafts 42 and 43 project beyond the bearings 44 to form the shaft extensions 78 and 79. Upon these shaft extensions are mounted two similar spur pinions 80 and 81 slidable longitudinally there of and connected rotatively therewith by suitable feather keys 82. The pinions 80 and 81 are provided with circumferential grooves 83 adapted to engage suitable shifting collars 84 for connection with the shifting devices by which the position of the pinion longitudinally of the shaft extension may be controlled. A suitable gear housing 85 is attached to the end plate 50 and completely encloses these pinions and the devices by Mounted in a journal bearing 86 of the gear housing 85, extending longitudinallyin the central planes of the casing, is a shaft 87 to the projecting end ofwhich is attached a clutch member 12 by which the rotative parts of the engine are connected to drive. any preferred transmission mechanism, as for example, that connected with the cutting mechanism of a mining machine. 7 At the inner end of the shaft 87 is a spur gear 88 adapted to mesh with the spur pinions 80 and 81 when they are at the inner end of their movement along the shafts 78 and 79. The width of the gear 88 is such, however, that when the said pinions are at the outer limit of their movement they will be out of engagement with said gear. Mounted in bearings of the gear housing 85 is a transverse shaft 89 to which is attached a pair of rocker arms 90 having apertures engaging the trunnions 91 of the shifting collar 84 which engages the groove 83 in the pinion 80. Rotatable upon the shaft 89 is a quill 92 to which is attached a pair of rocker arms 93 having apertures engaging the trunnions 91 of the shifting collars 84 which engages the groove 83 of the pinion 81. The

shaft 89 and quill 92 project beyond the bearing 85a and to their projecting ends are attached rocker arms 94 and 95 respectively. To these rocker arms are connected the rods 96 and 97 which extend to a point convenient to the hand of the operator. By the manipulation of these operating rods 96 and 97 the shaft 89 and quill 92- may be rotated to oscillate the rocker arms 90 and 93 to shift the pinions 80- and 81 into or out of engagement with the gear wheel '88. As the rotors 39 and 40 revolve in opposite direction it necessarily follows that the direction of rotation of the shaft 87 will depend upon which of the pinions 39 and 40 is in engagement with the wheel 88. By this arrangement means is afforded to drive the shaft 87 and the machinery connected therewith in either direction or to entirely disconnect it from the ro tatingparts of theengine. 1

bearings 101 and 1020f a gear housing 103 attached to theend plate51. The inner end of the shaft is supported in a suitable seat in the'end plate 51, and is there provided with a thrust end bearingfas shown in Figure 1.' Upon the shaft 100 is formed aworm 104 which engages a worm wheel105 mounted upon the vertical shaft 36 journaled in bearings 1'07 and 108 of the gear housing 103. The shaft 36 may be connected with any preferred transmission mechanism such, for example, as the feeding devices of a mining machine. a

In Figs. 1 and 4 of the drawings I have illustrated a preferred rotor construction wherein the drums 39 and 40 are built up of series of similar discs 109, preferably about half an inch in thickness, which are stacked upon the shafts 42 and 43. These discs 109 are each provided with a central circular aperture, adapted to fit closely upon the shaft, and are securely clamped between the collar 106 preferably formed integral with the shaft, and the clamping rings 106a threaded thereto. A key110 secures them against rotation relative to the shaft and each central circular aperture is provided with four equally spacedkey ways 111 each of which is fitted to the key 110. Formed on the periphery of each disc are gear teeth 112which may be of any'suitable form and r of any preferred number which is indivisible V by the number of key ways 111. In the example here illustrated I have provided fifteen teeth of the customary involute form. The relation of the gear teeth 112 to the key way 111 is such that when assembling the discs upon the. shaft, the rotation of each disc through one quarter of a revolution relative to the next adjacent disc, will formspirally disposed zig-zag tooth blades having a gencral inclination of approximately forty-five degrees to a line drawn parallel with the axis of the rotors; These'spirally disposed zigzag tooth blades are arranged to diverge from the transverse central plane of the rotors towards its ends and to extend around approximately one-fourth of the circumference of the rotor. When such rotors are mounted in the casings 37 as above descrlbcd,

these spirally disposed tooth blades of one rotor intermesh with those of the other rotor and co-operate with the contacting surface 58 of the casing to form V shaped expansion chambers 59 as above described. Should the number of teethformed upon the periphery ofeach disc be other than fifteen, or should the number of key ways in each disc be other than four, it is apparent that the angle formed between the resulting spiral tooth v blades and the longitudinal lines of the rotor would be different from-that here illustrated,

in which case the circumferential extent of the contacting surface 58 of the casing would be made to conform to the spiral advance ofthe gear teeth of the rotors. I I

It is to be understood, however, that I do not limit'myself to the construction above described, andin Fig. 6 of the drawings have illustrated an alternative construction wherein each rotor is composed of two metallic cylinders 113 and 114 keyed to the shaft and clamped in place between the collar 106 a and the clamping ring 106m Upon the cylinder 113 is formed a plurality of lefthand spiral gear teeth 115 each ofwhich extends from GIld tO end of the cylinder and around about one-fourth of its circumference.

Uponthe cylinder 114 is formed similar right hand spiral gear teeth 116 extending from end to end of the cylinder and around about cumferenceof each as above described.

worm 104 and worm wheel 1.05, may be omitted. In such case the shaft extension 42a may be removed from the shaft 42, a clamping member 47 substituted. for the 1. In an engine of the class described, the v combination with arpair of drums provided with a plurallty of lntermeshing zigszag gear,

tooth pistons and corresponding grooves diverglng 1n helical lines from the centralplane of the drums and each extendlng over a portion of the circumference to the endsthereof,

of a casing having a wall in close proximity on the inlet-side only wlth the top of the gear teeth and'cooperating therewith to produce sets of expansion chambers, a port in said casing for admitting vfluid at the meeting point of the successive grooves and gear tooth pistons during the rotation of the drums, an open ended. elongated exhaust port in said casing wall spaced from said admission port inthe direction of rotation of the drums and extending. longitudinally from end to end thereof, and clearance space at both ends of said drum auxiliary to said exhaust port as and for the purpose set forth.

2. In an'engine of the class described, the combination with a pair of drums having a. plurality of intermeshing gear tooth pistons and corresponding grooves diverging in helical lines from the central plane of the drums and each extending over a portion of the circumference to the ends thereof, of a casing having a wall in close/proximity on the inlet side only with the tops of the gear teeth and cooperating therewith to produce sets of expansion. chambers, said wall extending over a part of said drums equal to the circumferential advance of the tooth pistons, a port in said casing wall for admitting fluid at the meeting point of the successive grooves and gear tooth pistons during the rotation of the drums, and an open ended exhaust chamb'er extending the entire length of the drums and across their ends as and for the purpose set forth.

3. In an engineof the class described, the combination with a casing, of a pair of rotors having intermeshing spirally disposed tooth blades, each rotor consisting of a shaft having a longitudinal key upon which is stacked a plurality of discs, a central circular aperture in each disc adapted to fit upon the shaft and provided with a relatively small number ofkey ways, a relatively large number of gear teeth which is indivisible by the number of key ways formed upon the periphery of each disc, each disc being advanced one key way space beyond the next adjacent disc thereby producing a relation of'gear eeth to forn spiral tooth vanes upon the resulting drum.

I l. In an engine of the class described, the combination with a casing, of a pair of rotors having internieshing spirally disposed tooth blades, each rotor consisting of a shaft having a longitudinal key upon which is stacked a plurality of disks, a central circular aperture in each disk adapted to fit upon the shaft and provided with a relatively small number of key ways, a relatively large number of gear teeth formed upon the periphery of each disk, each disk being advanced one key way space beyond the next adjacent disk hereby producing a relation of gear teeth to form spiral tooth vanes upon the resulting drum.

5. In an engine of the class described, the combination with a pair of drums having a plurality of intermeshing gear tooth pistons and corresponding grooves, of a casing having a wall in close proximity on the inlet side only with the tops of the gear teeth and cooperating therewith to produce sets of expansion chambers, said wall extending from p the meeting line of the drums in the direction of rotation over a portion less than half the circumference of the drums, supply devices including control means to, alternately admit and cut off the flow of expansive fluid to wards said expansion chambers, an admission chamber between the control means and the expansion chambers, and means to prevent the fluid pressure within the admission chamber falling below a predetermined limit.

6. In an engine of the class described, the

combination with a pair of drums having a plurality of intermeshing gear tooth pistons and corresponding grooves, of a casing having a wall in close proximity on the inlet side only with the tops of the gear teeth and cooperating there-with to produce sets of expansion chambers, said wall extending from the meeting line of the drums in the direction of rotation over a portion of the circumference of the drums, an exhaust chamber positioned opposite said casing wall and extending longitudinally of said drums from end to end thereof, supply devices including control means to alternately permit and cut off the flow of expansive fluid towards said expansion chamber, an admission chamber between the control means and the expansion chamber, and automatically acting means to equalize the pressures in said exhaust chamber and said admission chamber when the supply of expansive fluid is out off.

7. In an engine of the class described, the

combination with a pair ofdrums having a plurality of intermeshing gear tooth pistons and corresponding grooves, of a casing having a wall in close proximity on the inlet side only with the tops of the gear teeth and cooperating therewith to produce sets of expansion chambers, said wall extending from the meeting line of the drums in the direction of rotation over a portion of the circumference of the drums, an exhaust chamber positioned opposite said casing wall and extending longitudinally of said drums from end to end thereof, supply devices including control means to alternately permit and cut of the flow of expansive fluid towards said expansion chamber, an admission chamber between the control means and theexpansion chambers, and automatically acting means to connect said admission chamber with the ex- Y ternal atmosphere when the supply of expansive fluid is cut off.

8. The combination of a casing having concave walls, a plurality of rotors having intermeshing blades mounted in said casing with their blades in substantially air tight relation with the walls thereof on the inlet side only, fluid pressure control means for admitting and cutting off fluid pressure to said rotors, and a second fluid pressure control means to admit fluid pressure to said rotors on the inlet side upon cessation of pressure from said first mentioned control means.

9. The combination of a casing having concave walls, a plurality of rotors having inintermeshing blades mounted in said casing with their blades in substantially air tight relation with the walls thereof on the inlet side only, fluid pressure control means for admitting and cutting ofl fluid pressure to said rotors, and a normally closed valve operableautomatically upon cessation of fluid pressure from said first mentioned control means to admit fluid pressure to the inlet side of said rotors.

11. The combination of a casing having two fluid pressure inlets, a plurality of rotors mounted in said casing with their blades in substantially air-tight relation with the walls thereof on the inlet side only, fluid pressure control means for one of said inairtight to the teeth of said rotors on the inlet side, fluid pressure means delivering to a chamber between said partition wall and the wall of the casing, and a secondnormally closed fluid pressure inlet delivering to said chamber, said second inlet having an inlet valve operable automatically to open said inlet and admit pressure to the chamber upon reduction of pressure therein to a predetermined limit.

15. In a machine of the class described, an open casing divided by a curved partition wall having a fluid pressure inlet port into a closed fluid pressure chamber and an open rotor chamber, a pair of rotors having inter meshing teeth fitted substantially airtight on the inlet side to said curved partition wall, a fluid pressure inlet for said fluid pressure chamber on the opposite side of said curved wall, and a second fluid pressure inlet for C said fluid pressure chamber provided with a normally closed valve, which is automatically operable on reduction of pressure to alpredetermined limit in said fluid pressure chamber to admit pressure thereto.

In testimony whereof I affix my signature.

' NILS D. LEVIN.

lets, and a second fluid pressure control means for the other of said inlets to admit fluid to said casing upon drop of fluid pressure at the first named inlet.

12. The combination of a casing having two fluid pressure inlets, a plurality of rotors mounted in said casing with their blades in substantially air-tight relation with the walls thereof on the inlet side only, fluid pres sure control means for one'of said inlets, and a second fluid pressure control means for the other of said inlets automatically operable to admit fluidto said casing upon drop of fluid pressure at said first named inlet.

13. In a machine of the class described, the combination of a pair of rotors having intermeshing teeth, a casing having a curved wall provided with a fluid pressure inlet port and fitted substantially airtight to the teeth of the rotors on the inlet side and having an open exhaust chamber on the outlet side of said rotors, a fluid pressure chamberadjacent said curved wall and delivering to said fluid pressure inlet port, means for delivering pressure to said fluid pressure chamber, and a second normally closed pressure delivering means communicating with said fluid pressure chamber, said second pressure delivery means being operative automatically to deliver pressure to said fluid pressure chamber upon reduction of pressure therein to a predetermined limit.

14;. In a machine of the class described,

the combination of a pair of rotors having intermeshing teeth, an open casing enclosing said rotors, a curved partition wall having a fluid pressure inlet port fitted substantially

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