In a rotary engine there is provided a stator having a cavity in which a rotor is mounted for rotation about a fixed axis of rotation. Between the stator and rotor there is formed an annular space including a relatively narrow, concentric, intermediate space segment between a larger upstream space segment and a larger downstream space segment effecting a relatively high compression of a fuel-air mixture induced into the upstream space segment by rotation of the rotor. The rotor has radially movable vanes which ride on stationary cam surfaces at each end thereof and are urged outwardly against the inner wall of the stator with sealing rings carried on the vanes and between the stator and rotor which divide the annular space into separate working chambers. A fuel-air mixture is successively induced through an inlet port in the stator into the upstream space segment where it is then compressed and ignited in the intermediate space segment to propel the rotor. The resulting products of combustion are exhausted via the downstream space segment and through an outlet port in the stator for each revolution of each vane.

Current U.S. Class:	418/92 ; 418/147; 418/264
Current International Class:	F01C 1/00 (20060101); F01C 1/344 (20060101); F02b 055/14 ()
Field of Search:	123/8.45 418/148,147,145,261,260,144,142,92,93

Lewis, Jr.; Ancel W.

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Claims

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What is claimed is:

1. In a rotary engine the combination comprising:

a stator having a main housing with a cavity formed as a throughbore and an inlet port for passing a fuel-air mixture into the cavity and an outlet port for passing products of combustion from the cavity, said main housing having a water jacket, and end caps attached to the ends of the main housing forming the ends of the cavity, each of said end caps having a recessed portion in the inner side thereof;

a rotor having a rotor body having three radial slots arranged at 120.degree. intervals with a circular transverse cross section mounted for rotation about a fixed axis in bearings supported in the end caps, said rotor being undercut in each end forming an inner recess and an overhanging end portion that projects into the recessed portion in an associated end cap;

the stator and rotor defining therebetween and annular space including a relatively narrow, intermediate space segment formed by surfaces arranged concentric with the fixed axis and extending through an arc between about 135.degree. and about 225.degree. from a reference of 0.degree. between the inlet port and outlet port, a larger generally crescent-shaped upstream space segment in communication with the inlet port formed by concave stator surfaces arranged eccentric with the fixed axis and extending through an arc between about 0.degree. and 135.degree. from a reference of 0.degree., a larger generally crescent-shaped downstream space segment in communcation with the outlet port formed by concave stator surfaces arranged eccentric with the fixed axis and extending through an arc between about 225.degree. and about 360.degree. from the reference of 0.degree., each of said intermediate, upstream and downstream space segments being joined by a convex stator surface formed by a radius having its center externally of the stator;

three radial vanes, each vane having an oblong vane body slidably movable in one of the radial slots, each said vane body having a rounded inner end with bearing means adapted to move over a cam surface and a circular groove in the outer end carrying a generally circular head rotatable in the groove and a sealing ring movable in the head;

a cam on the end caps at each end of the rotor having cam surfaces projecting into the inner recess of the rotor and having a contour similar to that of the stator cavity on which the inner ends of the vanes ride as the rotor is rotated to urge the ring carried by the head against the inner peripheral surface of the stator defining the cavity with the head rotating relative to the vane body;

sealing means between the rotor and the vane body in the slots;

first sealing rings in grooves in the periphery of the overhanging end portion of the rotor body in engagement with recessed portions of the end caps;

second sealing rings in grooves at the ends of the overhanging end portions of the rotor body in enagement with the recessed portions of the end caps;

said stator, rotor vanes and sealing means, first sealing rings and second sealing rings dividing the annular space into separate working chambers between each two adjacent vanes to confine the fuel-air mixture thereto whereby a fuel-air mixture is successively induced through the inlet port into the upstream space segment between two adjacent vanes and then compressed in the intermediate space segment between two adjacent vanes upon rotation of the rotor;

an ignition element positioned in the intermediate space segment for igniting the compressed fuel-air mixture just upstream of a vane to propel the rotor and produce products of combustion by the ignition whereby movement of the vane moves the resulting products of combustion through said downstream space segment and out the outlet port for each revolution of each vane.

2. In a rotory engine as set forth in claim 1 wherein each said head has a pair of spaced radially projecting portions on opposite sides of the sealing ring that engage the inner surface of the stator housing.

3. In a rotoary engine as set forth in claim 1 wherein said ignition element is mounted at about 225.degree. in from a reference of 0.degree. and opens into the intermediate space segment ahead of the downstream space segment.

4. In a rotary engine as set forth in claim 1 wherein said circular groove in each vane extends through an arc of more than a semi-circle to retain the associated head therein.

5. In a rotary engine as set forth in claim 1 wherein each crescent-shaped upstream and downstream space segment is provided by a concavity in the stator including a first arcuate segment having a first radius and a second arcuate segment having a second radius, said first and second radius having different centers internally of the stator and each having a radius less than the radius of the rotor.

6. In a rotary engine as set forth in claim 1 wherein said vane body has a passage between the inner end and the outer end to pass a lubricant from the rotor body to the groove.

7. In a rotary engine as set forth in claim 1 wherein said rotor has a hub with internal gear teeth, and an output shaft with external gear teeth arranged to reduce the output speed of the output shaft relative to the movable body.

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Description

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BACKGROUND OF THE INVENTION

This invention relates to rotary-type internal combustion engines.

Rotary-type internal combustion engines in general offer a distinct advantage over piston-type engines in that there are no reciprocating pistons which have to be alternately accelerated and retarded. The most commonly know rotary-type engine is the "Wankel" engine which in general has a triangular shaped rotor with three convexly curved sides mounted for rotation in a stator having an internal cavity of a generally oval shape. The rotor is mounted for rotation about an eccentrically moving axis of rotation as distinguished from a fixed axis of rotation which construction has a tendency to cause difficulty with seals between the working chambers formed between the rotor and stator and to cause an undue amount of wear and deleterious vibration on the rotor and stator.

Accordingly, it is a general object of this invention to provide a novel rotary-type engine having a plurality of working chambers formed between the stator and rotor and principally characterized by having a high compression of the fuel-air mixture, being smooth in operation and avoiding undue part wear.

Another object of this invention is to provide a rotary-type engine which is considerably easier to seal between the multiple working chambers and between the stator and rotor and affords a higher compression of the fuel-air mixture than previously known rotary-type engines.

Still a further object of this invention is to provide a rotary-type engine characterized by having a rotor that rotates about a fixed axis of rotation and radially reciprocating vanes having inner ends which move on stationary cam surfaces throughout each revolution together with sealing rings at the outer ends of the vanes and between the stator and rotor which confine the fuel-air mixture during rotation of the rotor in such a way as to carry out induction of a fuel-air mixture, a relatively high compression of the fuel-air mixture, ignition and exhaust of the products of combustion in an annular space formed between the stator and rotor as the rotor is rotated.

In accordance with the present invention in a preferred embodiment shown there is provided a stator with a cavity having a generally eccentric transverse contour in which a rotor body with a circular cross section is rotated about a fixed axis forming an annular space between the stator and rotor. The rotor has circumferentially spaced, radially reciprocating vanes which are urged by stationary cam surfaces at each end of the rotor against the inner peripheral wall of the stator to form working chambers between adjacent vanes as the rotor is rotated. A fuel-air mixture is induced through an inlet port in the stator into an upstream space segment and is then compressed and ignited in a relatively narrow, concentric, space segment followed by having a vane move the resulting products of combustion through a downstream space segment and out an exhaust port in the stator. Sealing rings are provided between the vanes and the stator and between the stator and rotor to confine the fuel-air mixture to the working chambers. A lubricating system provides lubrication for the reciprocating vanes and sealing rings.

Other objects, advantages and capabilities of the present invention will become more apparent as the description proceeds taken in conjunction with the accompanying drawings in which:

FIG. 1 is a perspective view of a rotary engine embodying features of the present invention with some parts exploded and separated for clarity;

FIG. 2 is a vertical sectional view through the center of the engine along longitudinal axis thereof with one of the vanes disposed in the upright or straight-up position;

FIG. 3 is a sectional view taken along lines 3--3 of FIG. 2;

FIG. 4 is a sectional view taken along lines 4--4 of FIG. 2;

FIG. 5 is a perspective view of a corner portion of the rotor;

FIG. 6 is a perspective view of one of the vanes;

FIG. 7 is an end elevation view of one of the vanes;

FIG. 8 is a sectional view taken along lines 8--8 through the vane of FIG. 7.

Referring now to the drawings, there is shown a rotary engine which, in general, comprises a stator S having an internal cavity K in which there is mounted for rotation a rotor R. In general, the internal peripheral surfaces of the stator defining the cavity together with the external peripheral surfaces of the rotor form an annular space described more fully hereinafter. The rotor R has radially extending vanes designated VA, VB and VC which are mounted for reciprocating movement; the rotor R being arranged for rotation about a fixed axis of rotation at the center of the stator and rotor designated X in FIG. 3.

The stator S has a main housing 21 open at the ends with the cavity K formed therein as a throughbore and end caps 22 and 23 close the ends of the housing and define the end boundaries of the internal cavity K. The end caps are shown as being held in place on the housing 21 by bolt-type fasteners F.

The contour or shape of the inner peripheral surface of the housing defining the cavity K is broken into several distinct concave and convex arcs or segments of a circle some of which are eccentric relative to the center of the cavity and axis of rotation for the rotor designated X. With particular reference to FIG. 3, the arcs or radii of circles making up the contour of the inner peripheral surface of the stator are between points designated by numerals 1 and 2, 2 and 3, 3 and 4, 4 and 5, 5 and 6, 6 and 7, 7 and 8, and 8 and 1. The arcs between points 3 and 4, 4 and 5, and 8 and 1 are convex arcs which have a center point externally of the housing while the other arcs have a center point inside the housing and only the arc between points 4 and 5 is measured from the center of the housing and is concentric with axis X. A concave generally V-shaped recess 24 is provided in the housing at a position about 225.degree. from the reference at 0.degree. as measured in a clockwise direction as shown in FIG. 3.

The main housing 21 has two fuel-air mixture inlet passages 25 in the top thereof with associated inlet ports 25a located at the arc between points 8 and 1 to the right side of a vertical dividing line through the housing as viewed in FIG. 3 through which a mixture of fuel and air is induced into the annular space as described hereinafter and an exhaust outlet passages 26 in the top thereof with an outlet ports 26a in the arc between points 8 and 1 on the left side of the vertical dividing line through the housing. The inlet and outlet passages leave bridges on the sides and at the center of the housing. The main housing 21 further has communicating internal spaces 27 forming a water jacket for cooling and bolt holes 28 for fastening the end caps to the housing with suitable fasteners with bolts F. The housing 21 also supports an ignition element 29 in the form of a spark plug mounted at the 225.degree. position.

The end caps 22 and 23 are similar in construction and are shown as being made up of inner and outer plates designated 31 and 32, respectively, which are separable from one another for convenience of manufacture. Each inner plate 31 has a circular recess 33 in the inner face sized to receive an end portion of the rotor R leaving an outer overhanging portion 34 and a central protruding hub portion 35. Each inner hub portion 35 is externally contoured to provide a cam surface 35a similar in shape to that of the inner peripheral surface of the stator forming the cavity over which the inner ends of the vanes move so that the vanes at all times are urged outwardly against the inner peripheral surface of the housing during the rotation of the rotor. Each outer plate 32 has a circular recess 37 in the inner face thereof and each inner plate 31 has a circular recess 38 matching recess 37 to form an oil reservoir L in the end caps for lubrication purposes as described hereinafter. A flywheel 39 is mounted for rotation in one of the reservoirs in end cap 22 to assist in circulating the lubricating oil to and from reservoir L.

The rotor R has a main rotor body 41 that is circular in transverse cross section and generally cylindrical in shape with three radially extending slots 43 located at 120.degree. intervals around the rotor body which slidably receive and support the three vanes VA, VB and VC for a reciprocating movement therein. The radial slots 43 do not extend the full length of the rotor body leaving circumferentially continuous outer overhanging end portions 44 at each end of the rotor body. The rotor body 41 further has a circular radial groove 45 at each end formed in the outer peripheral surface thereof adjacent the ends of the radial slots each receiving a sealing ring 46. Sealing ring 46 is of a construction similar to a piston ring in an engine with an expansion slot formed therein and engages the inner axial surface of plate 31 to form a seal between the stator and rotor. The rotor body 41 further has a circular radial groove 47 in each end thereof for receiving a sealing ring assembly inclusive of an outer ring 48, intermediate spring 49 and inner ring 50, the ring 48 bearing against a section of the inner ring 55. Inner ring 55 forms a continuous loop along the ends in groove 47 which extends through a groove 51. The portion of ring 55 in groove 47 bears against the inside of the vane to provide a seal between the rotor body 41 and the outer side edges of each of the vanes and the portion of ring 55 in groove 51 bears against the face of the vane to confine the fuel-air mixture to the working chambers.

The rotor body 41 is undercut at each end leaving an overhanging outer end portion 44 and an inner hub portion 52 of cylindrical shape which is provided with internal gear teeth 53. The rotor body 41 is supported for rotation by the stator with a bearing 54 at each end. The inner hub portion 52 extends inside and is affixed to the inner race of the bearing 54 and the outer race is mounted in and affixed to the hub portion 35 of the end cap.

An output shaft 56 is mounted for rotation within the inner hub portions 52 of the rotor body in bearings 57 at each end thereof. The bearings are affixed to the end caps and are specifically shown as recessed in the hub portion of the outer plate 32. The output shaft 56 has external gear teeth 58 which mesh with the internal gear teeth 53 in the hub portion of the rotor body to provide a speed reduction in the output shaft 56 from that of the rotor body 41. A two-to-one speed reduction is preferred but it is understood the speed may be increased or decreased between the rotor body and output shaft.

The vanes VA, VB and VC are of identical construction and each comprise a main vane body 61 of generally oblong shape with smooth flat sides and ends which slide freely into an associated generally U-shaped radial slot 43 in the rotor body and reciprocate therein as the rotor body is rotated. The lower end of the vane body engaging the cam surface is rounded at 61a and bearings 62 in the form of sleeves are provided at each end rollable on shaft sections 63 to reduce the friction. The outer edge of the vane body 61 has a circular groove 65 extending through an arc of greater than 180.degree. in which there is mounted a rotatable head 66 which rotates about its center in and relative to the groove as the angular position of the vane changes relative to the stator housing 21. The head 66 has a generally circular transverse cross section with a pair of radially projecting ear portions 66a and 66b. A slot 67 is provided in the head, between the ear portions which receives a spring 68 and a ring 69 to effect a moving seal between the outer edge of the vane and the inside of the stator housing as the rotor rotates and the cam surface 35a urges the ring into engagement throughout a full revolution of the rotor.

In the engine assembly as best seen in FIG. 2, the peripheral sealing rings 46 engage an inner axial wall portion 33a of the inner plate 31 and the end sealing ring 48 engages the inner axial wall 33b of the inner plate 31. Rings 46 also engage the outer side edges of the vanes to seal across the ends thereof as best seen in FIG. 5. The vanes VA, VB and VC travel in a path established by the stationary cam and cavity surfaces of the stator with the heads 66 rotating so that ring 69 is at all times flush against the cavity surface.

For the lubrication of the vanes in their associated slots the oil from the reservoir L at the ends of the housing is agitated by the flywheel 39 and moved into the crescent-shaped space between the shaft 56 and hollow hub portion 52 as best seen in FIG. 2. The vane body 61 has a hole 61a extending therethrough opening into the upper groove 65 at its upper end and into an opening 35' in the hub and an opening 52' in hub 52 leading into the crescent-shaped space between rotor 56 and hub 52. As the vanes rotate about the axis they reciprocate in the slots and thereby pump the oil from the crescent-shaped space and reservoir up into the groove 65 to lubricate the vanes and the associated sealing ring 69.

As best seen in FIG. 3 the annular space formed between the stator and rotor is divided into several distinct space segments. For reference purposes beginning at the 0.degree. position and proceeding in a clockwise direction as viewed in FIG. 3 the first space segment herein referred to as the "upstream space segment" and designated S1 spans an arc of about 120.degree. measured in a clockwise direction from a vertical 0.degree. reference. This upstream space segment S1 has a generally crescent-like shape. The upstream space segment S1 is in communication with the inlet port 25a. Proceeding further in the clockwise direction, the next annular space segment herein referred to as the "intermediate space segment" is designated S2. Segment S2 covers about 120.degree. and is a relatively narrow gap formed by essentially two opposed surfaces of the stator and rotor which are concentric relative to axis X. Within this intermediate space segment S2 at the downstream end portion thereof at about 225.degree. angle from the 0 reference the recess 24 in the stator and opposed concentric rotor surface forms an enlarged space segment S3 into which a major portion of the fuel-air mixture is compressed for ignition. Recess 29 is provided with brides like passages 25 and 26 to facilitate the sliding movement of the vanes thereover. The ignition element 29 is mounted in the housing 21 and the spark gap portion thereof is located in the space segment S3 to ignite the compressed fuel-air mixture. The gap forming intermediate space segment S2 is shown as being fairly wide in the drawings for clairity but it is understood that it is quite small to provide a high compression of the fuel-air mixture and confine the mixture to the area of the spark gap of the plug 29. The next annular space segment between the stator and rotor designated S4 hereinafter referred to as the "downstream space segment" extends from the 240.degree. to 360.degree. or back to the 0.degree. reference.

As used herein, "upstream" is with reference to being toward the source of the fuel-air mixture and "downstream" is with reference to being away from the source of the fuel-air mixture and further in the area at which the combustion is being discharged.

It is noted that the convex surface portions between points 1 and 8, points 3 and 4 and points 5 and 6 of the stator are closest to the periphery of the rotor so that three distinct working chambers are readily apparent when one of the vanes is upright and the other vanes have the ring portions engaging a part of the other concave surface portions as shown in FIG. 3.

OPERATION

The complete sequence of operation will now be described with reference to FIG. 3 taking the vane VA and following its movement in a clockwise direction from a center upright reference 12 0'clock or 0.degree. position.

In the previous cycle just before vane VA reaches the 0.degree. position, gases have been induced between vanes VA and VC via intake port 25a. Vane VA then moves from the 0.degree. position past intake port 25a to position A-1 (22.degree.) which is the beginning of the induction cycle for the fuel-air mixture in the working chamber between vanes VA and VB. As vane VA moves through the upstream space segment S1 to position A-2 (40.degree.) more of the fuel-air mixture is drawn or induced into the upstream space segment between vanes VA and VB.

At about position A-3 (60.degree.) for vane VA the gases which had been induced between vanes VA and VC are beginning to be compressed in the downstream position of the crescent-shaped segment S1 between vanes VA and VC continues until vane VA is at position A-5 (120.degree.). At this point, the fuel-air mixture is fully compressed in the intermediate space segment S2 and particularly in the compression space S3 between vanes VA, vane VC and the rotor and stator walls.

With vane VA at the A-5 position the ignition at the spark gap of element 29 occurs igniting the compressed fuel-air mixture between vanes VA and VC which then moves vane VA to the A-9 (240.degree.) position where it is ready for another ignition. This next ignition which is the power stroke for vane VA which then pushes or propels the rotor further in a clockwise direction by applying forces to the surface of the rotor and in a direction normal to that portion of the vane VA extending beyond the rotor.

Beginning at position A-9 for vane VA, upstream thereof in the downstream space segment S4 the exhaust gases from the previous ignition are started to be swept or forced out the exhaust port 26a and as vane VA is moved from position A-9 (240.degree.) to position A-12 (315.degree.) they are exhausted. The vane VA continues to rotate through downstream space segment S4 until it has completed a full revolution and then starts through the next cycle in which the same procedure per cycle or revolution is accomplished for each of the three vanes VA, VB and VC for each revolution so there are three inductions, compressions, ignitions and exhausts for each revolution of the rotor.

During the rotation of the rotor body 41 the inner ends of the vanes follow a course established by cam surface 35a and the outer ends of the vanes follow a course established by the contour of the housing causing the vanes to reciprocate in the slots. This in turn draws or pumps oil from the space between the shaft.

From the foregoing description of the preferred embodiment, it is apparent that by having the rotor rotate about a fixed axis that there will be less vibrations and easier to seal between the working chambers. Moreover, the use of principally concentric surfaces in the area of ignition facilitates a high compression of the fuel-air mixture and results in a high efficiency.

Although the present invention has been described with a certain degree of particularity, it is understood that the present disclosure has been made by way of example and that changes in details of structure may be made without departing from the spirit thereof.

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