US2651177A - Rotary piston internal-combustion engine - Google Patents

Description

P 8, 1953 J. E. PRlD HAM 2,651,177

ROTARY PISTON INTERNAL-COMBUSTION ENGINE Filed Nov. 8, 1949 5 Sheets-Sheet 1 gal Iv vf/vnm Z1155 [ye/em 7%06 4;

Sept. 8, 1953 J. E. PRIDHAM ROTARY PISTON INTERNAL-COMBUSTION ENGINE 3 Sheets-Sheet 2 Filed Nov. 8, 1949 13y VE/VfdK Sept. 8, 1953 J. E. PRIDHAM 2,651,177

v RC TRY PISTON ZNTEFNAL-COMBUSTION ENGINE Filed Nov. 8, 1949 a Sheets-Sheet s Eff frat Jams [nae/2K baby/9%;

Patented Sept. 8, 1953 ROTARY PISTON INTERNAL-COMBUSTION ENGINE James Everard Pridham, Parkstone, England Application November 8, 1949, Serial No. 126,151 In Great Britain November 2, 1948 4 Claims. (01. (ill-39.61)

This invention relates to rotary piston internal combustion engines and is concerned with the provision of a generally improved engine of this type having a high mechanical efficiency and which is generally economical in operation.

According to the present invention, a rotary piston internal combustion engine comprises a stator having an annular channel opening into one face thereof and a rotatable wheel or disc secured on a driving shaft and arranged, in conjunction with said channel, to provide an annular cylinder having at least one fuel inlet and at least one exhaust outlet, and further comprises at least two pistons or vanes mounted on the said wheel or disc and arranged to work in the said cylinder, and at least two rotary abutments, one of which is shaped to provide at least one combustion recess in its outer wall surface, the abutments being in driven connection with the said shaft and arranged to work in abutment cylinders which overlap the annular cylinder so that the abutments traverse the said annular cylinder during their rotation and divide it intermittently into a number of compartments, the arrangement being such that fuel can be drawn into the cylinder by one piston, compressed into a combustion recess by a following piston, fired in said combustion recess and then released behind said following piston to drive the piston around the said cylinder.

In order that the invention may be clearly understood and readily carried into effect one embodiment thereof will now be described in detail with reference to the accompanying drawings, wherein:

Figure 1 is a cross-sectional elevation of the engine, the main shaft being partially broken away,

Figure 2 is a section on the line II--II of Figure 1, the rotor having been moved through 120 in a clock-wise direction for purposes of illustration, and

Figure 3 is a part sectional elevation on the line IIIIII of Figure 2.

Referring now to the drawings, the stator is in the form of a substantially circular plate I having a concentric annulus I a. extending around the marginal edge of the rear face, a channel 2 being formed in said annulus, said channel opening into the opposite or front face of the plate. A web portion 3 extending diametrically across the annulus is formed on the rear face of the.

plate I and a central concentric aperture is formed through the plate and web portion, the latter being provided with a boss 3a as shown in Figure 1. A rotatable disc or wheel 4, having a raised annular rim 4a around the outer margin of one face, and secured on the main shaft 5 which passes freely through the aperture in the plate and web with the inter-position of a. bearing bushing I3, is arranged to co-operate with the channelled front face of the plate I so that the rim 4a, enters the channel 2 to form an enclosed working space or cylinder. Secured at diametrically opposed points on the rim 4a of the wheel 4, and extending substantially perpendicularly from the rim surface, are two vanes or pistons I which are arranged to work in the enclosed annular working space or cylinder 2.

The plate I is formed with crescent-shaped extensions Ib opposite the ends of the web 3 and the outer wall of the annulus la is formed with corresponding extensions I c which, together with the adjacent end faces of the web 3 form the walls of abutment cylinders 20. which overlap the main cylinder 2. Conical projections Id are formed on the rear face of the plate I concentrically within the abutment cylinder 20 the reduced ends of these projections terminating in fixed spindles 8. The abutment cylinder walls are suitably interrupted and the projections Id are suitably channelled so that the cylinder 2 is continued therethrough without interruption. Hollow rotary abutments 9 having cylindrical outer surfaces and conical inner surfaces are mounted for rotation within the abutment cylinders 2a about the projections Id, the abutments being provided with concentric sleeve-like extensions I0 which engage around the spindles 8. Bearing bushes II are interposed between the extensions I0 and spindles 8 and the abutments are held against longitudinal displacement relatively to the spindles by means of nuts I2 which latter are screwed onto the outer ends of the spindles. The abutments 9, during their rotation, traverse the cylinder 2 and diametrically opposed slots 9a are formed in the walls of the abutments 9, to permit the passage of the pistons I therethrough when the position of the abutments is such that the slots 9d are in the path of the pistons.

The abutments 9 are rotated about the spindles 8 in timed relationship with the pistons 'I by means of pinions I3 keyed on the sleeve-like extensions Ill and driven by a pinion I4 keyed on the main shaft 5, through intermediate idler pinions I5. The pinions I5 are rotatably mounted on stub shafts I6 carried by cover plates I! which are fitted over the open ends of the abutment cylinders and bolted to flanges I-e around the outer edges of the cylinders. The pinions i5 are retained on the shafts 16 by nuts Ilia. The plates H are each provided with a central apertured boss l8 which is shaped to fit over and provide a bearing for the adjacent sleeve-like extension it with the inter-position of a bearing bush l8a.

Diametrically opposed recesses 9b are formed in the outer wall of one of the abutments 9, these recesses being arranged, when opposite the por tion ic of the wall of the abutment cylinder, to form closed combustion chambers in conjunction with the said wall portion. (See Figure 2.) A spark plug I9 is mounted in this wall portion of the abutment cylinder la in the path of the recesses 9b. W

The wheel or disc 4 is covered by means of a cover plate 20 which is bolted to the front face of the plate I and formed with a central aperture surrounded by an upstanding bushed boss 20a through which the shaft 5 extends and for which it provides a bearing, A fuel inlet 21 is formed in the wall of the cylinder 2 on one side of, and adjacent, the plain abutment 9, i. e. that which is not provided with the combustion recesses 9b, and an exhaust outlet 22 is provided in the wall of the cylinder on the other side of and adjacent the same abutment. The casing l is provided with a water jacket 23 which, in this embodiment, extends around that part of the cylinder wall in which the working stroke occurs.

The abutments 9 are rotated in timed relationship with the wheel 4 so that when a piston 1 reaches an abutment 9 during rotation of the wheel 4, the abutment is in a position in which the piston can pass through the slots 90. therein without interruption.

In operation, a piston 1 retreating from the fuel inlet port 2 l as shown in Figure 2, induces or draws a charge into the cylinder 2 behind the piston and passes through the abutment. This charge is compressed by the following piston into a combustion recess 9b in the rotating abutment 9 which the said following or compressing piston is approaching. As the compressing piston gets close to this abutment, the abutment moves into a position in which the piston can pass therethrough and substantially at the same time the combustion recess containing the charge is moved opposite the wall portion [c of the abutment cylinder which effectively closes the combustion recess 9b as aforesaid to form a closed combustion chamber. (A combustion chamber in the closed position is illustrated in Figure 2.) The continued rotation of the abutment carries the charge past the sparking plug l! at the same time as the piston is passing through the abutment and the timing is such that the release of the fired charge into the expansion section of the cylinder takes place in rear of the piston just after the piston has passed through the abutment so that the piston is driven round within the cylinder. Whilst being thus driven the leading surface of the piston serves to scavenge the cylinder and eject the exhaust gases of the previous explosion through the exhaust outlet 22, the plain abutment being then in the position in which it blocks the cylinder as illustrated. The plain abutment moves into a position in which the slots 9a are aligned with the cylinder as the piston approaches and the piston passes therethrough and draws in behind it a fresh charge at the same time compressing the charge which has previously been drawn in by the other piston, the cycle then continuing as previously.

As will be understood, the timing is so arranged that a piston advancing towards an abutment is either compressing a charge into a compression recess or alternatively sweeping exhaust gases through the exhaust outlet, and a piston retreating from an abutment is either performing the working stroke or the induction stroke. There are thus two firing strokes per revolution of the rotor.

Owing to the constant high speed of the surfaces of the working parts in the engine above described, gas-sealing devices as embodied in the present day reciprocating piston engine, in which the piston speed is comparatively low at the time of maximum pressure, will not be necessary. If

. the co-operating surfaces of the rotating and stationary working parts are left unpolished, unmachined or even suitably grooved, gas eddies will prove sufiicient to restrict gas leakage to a reasonable minimum. Moreover it is probable that such carbonisation as is permitted by the relative movements of the parts will improve performance.

The engine as described may be constructed in duplicate form with pistons working in annular cylinders on both sides of the wheel or rotor plate, and with abutments arranged face to face as desired, the central rotor revolving between them. Also any number of these engines may be arranged to work on a common shaft in order to form a complete power unit.

The uses of this engine cover all cases where rotary power is required and owing to its shape and possible multiplication on one shaft it is eminently suitable for propeller-driven aircraft or for embodiment within a composite propeller and jet unit. A variation of the compression and expansion ratio may be made if desired by a modified positioning of the abutments.

At the end of a compression stroke, there will remain a portion of compressed air or vapour which is not admitted to the combustion chamber, and a part of this cool air or vapour will be carried through the abutment by the piston and will be used to cool those parts of the engine most exposed to high temperatures. The remaining part may be released to the rear of the piston in question by means of an enlargement of the annular cylinder at the appropriate point, this released air or vapour being compressed once more by the following piston so that an increasing compression pressure is built up.

Such auxiliary requirements as carburation, fuel injection, lubrication, ignition and cooling can be effected by any of the well known methods.

I claim:

1. A rotary internal combustion engine comprising a driving shaft, a co-operating circularly grooved stator and rotor mounted on said shaft and arranged to provide an annular cylinder therebetween which is concentric with the shaft, at least two pistons mounted on said rotor to work in said cylinder, at least two abutment cylinders which overlap said annular cylinder, at least two slotted abutments mounted for rotation one in each said abutment cylinder so as to be capable of traversing said annular cylinder to divide it intermittently into a number of compartments, the slot in each said abutment being arranged to permit the passage of a piston there- .through when said slot is coincident with the cylinder, and at least one of said abutments being externally recessed to provide, in conjunction with the associated abutment cylinder wall. two diametrically opposed combustion chambers, a gas inlet and an exhaust outlet in said annular cylinder one on each side of an abutment, means for igniting fuel mixture in said combustion chambers and means for driving said abutments in timed relationship with said pistons whereby gas can be drawn into the annular cylinder by one piston, compressed into a combustion chamber by a following piston, fired, released behind said following piston to drive it around the cylinder and finally exhausted by the next following piston.

2. A rotary internal combustion engine comprising a stator, a rotor co-operating with said stator to provide an annular working cylinder, shaft means on which said rotor is concentrically carried, two pistons mounted at diametrically opposed points on said rotor and arranged to work in said cylinder, two diametrically opposed abutment cylinders which overlap said annular cylinder, two symmetrical abutments mounted for rotation one in each said abutment cylinder so as to be capable of traversing said annular cylinder and dividing it intermittently into a number of compartments, each said abutment being hollow and having its walls formed with diametrically opposed slots to permit the passage of a piston therethrough, and one of said abutments having two diametrically opposed external recesses to provide, in conjunction with the associated abutment cylinder wall, two opposed combustion chambers, a gas inlet and an exhaust outlet in said annular cylinder positioned adjacent to and one on each side of the non-recessed abutment, means for igniting fuel mixture in said combustion chambers in turn and means for driving said abutments in timed relationship with said shaft means whereby gas can be drawn into the annular cylinder by one piston, compressed into a combustion chamber by a following piston, fired, released behind said following piston to drive it around the cylinder and finally exhausted by the next following piston.

3. A rotary internal combustion engine as claimed in claim 2 in which said symmetrical rotary abutments are of hollow form having a substantially cylindrical outer surface and a substantially conical inner surface and each said abutment is mounted to revolve about a spindle which is also slotted for the passage of the pistons therethrough and which is secured on the stator.

4. A rotary internal combustion engine comprising a co-operating circularly grooved stator and a rotor forming an annular cylinder therebetween, pistons mounted on said rotor to work in said cylinder, a number of circular section hollow symmetrical rotary abutments arranged, on rotation, to divide said cylinder intermittently into a number of compartments, the walls of each said abutment being provided with diametrically opposed slots to permit the passage of said pistons therethrough when said slots are in alignment with the annular cylinder, two diametrically opposed combustion recesses provided in the outer surface of at least one said abutment, means for driving said abutments in timed relationship with said rotor, said piston functioning to supply fuel under pressure to said combustion recesses in turn, means for igniting fuel in a combustion recess and subsequently releasing it to drive a piston around the annular cylinder, and means for exhausting burnt fuel from said cylinder.

JAMES EVERARD PRIDHAM.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,069,742 Tygard Aug. 12, 1913 1,455,324 Cushman May 15, 1923 2,110,524 Hodges Mar. 8, 1938 2,418,793 Selden Apr. 8, 1947 2,466,759 Baylin Apr. 12, 1949 FOREIGN PATENTS Number Country Date 812,870 France Feb. 15, 1937 381,625 Italy July 15, 1940

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