US 3250260 A
Description (OCR text may contain errors)
y 1966 F. E. HEYDRICH 3,250,260
ROTARY ENGINES Filed Oct. 29, 1962 5 Sheets-Sheet l 1 0 6 0 g 0 Q Q o 0 0 D 0 4 o Q 2 0 )H o 3'16! Q If" I y 1966 F. E. HEYDRICH 3,250,260
ROTARY ENGINES Filed Oct. 29, 1962 3 Sheets-Sheet 2 y 1966 F. E. HEYDRICH 3,250,260
ROTARY ENGINES Filed 001;. 29, 1962 3 Sheets-Sheet 5 j MIXTURE United States Patent 3,250,260 RG'IARY ENGINES Fred Erhart Heydrich, 28 Gordon Road, Prospect, South Australia, Australia Filed Get. 29, 1962, Sen-No. 233,963 9 Claims. (Cl. 123-16) The present invention relates to improved rotary engines. Certain of the features herein disclosed are suitable for the construction of positive displacement engines such as compressors, pumps and hydraulic motors. Particular features are directed to embodiments of an internal combustion engine.
The use of rotary engines having sliding vanes mounted on the rotor is well known. Previous limitations have included low compression ratios, and sealing and wear problems associated with the sliding vanes, leading to low efi'lciency and inadequate life.
Accordingly, the object of the present invention is to provide an efficient long wearing rotary engine of simple construction and light weight and having improved reli ability.
In carrying out the invention I have appreciably re duced the sliding friction, while also minimising rotor vane jamming and inadequate vane-side sealing.
My engine comprises essentially two parts, a stator and a rotor. The stator has an oval or elliptical bore within which the rotor rotates.
The rotor vanes are supported by the rotor and move radially towards and away from the rotor axis of rotation, to maintain contact with the stator bore.
The ratio of the major and minor axes of the stator bore governs the compression ratio of the engine. By attaching end flanges to the rotor, in which the sides of the vanes are recessed, the problem of vane support is greatly reduced, and vane tilting and'jamming is minimised. Also, because of reduced vane bending stresses, a larger vane travel, in certain instances up to about 40 percent of rotor diameter, has become practical, while maintaining low wear rates of the blades and the stator bore.
By supporting the vanes with this type of rotor construction, vane jamming is greatly reduced and the reduction in stresses makes possible lighter constructions, including thinner vanes, this leading in turn to improved volumetric efficiency. Vane end wear due to rubbing on the cylinder bore is compensated for by radial outward accommodation of the vanes.
Most of the embodiments are directed to rotor structures having end flanges of greater diameter than the rotor drum, but one embodiment is directed to rotors having end flanges approximately equal in diameter to said drum. This form of construction is suitable in low power, low compression engines as used for model propulsion, lawn mowers, etc. The larger diameter end flanges afiord needed support for larger higher performance engines. In the case of end flanges extending beyond the periphery of the stator bore, the recessed blade or vane edges have full rubbing contact only with the stator bore, and the sliding of the vanes in their recesses dissipates much less power and causes much less wear than the full edgesliding contact of the previous art.
In the drawings the following exemplifications are shown:
FIGURE 1 shows an embodiment of the rotor drum;
3,250,260 Patented May 10, 1966 FIGURE 2 shows a sectioned view of an engine according to the invention;
FIGURE 3 shows a sectioned sketch of the engine on line 3-3 of FIGURE 2;
FIGURE 4 shows a sectioned view of the engine on line 4-4 of FIGURE 2;
FIGURE 5 shows a detail of the stator casing at th line 5-5 of FIGURE 3;
FIGURE 6 shows a side section view of a different embodiment of the engine having reduced diameter rotor end flanges;
FIGURE 6a shows an enlarged detail of the rotor structure of FIGURE 6;
FIGURE 6b shows a partial side section view of FIG- URE 6;
FIGURE 7 shows a side section view of another embodiment of the engine;
FIGURE 8 shows a partial section of an engine similar to that of FIGURE 2 and embodying an internal vane control cam;
FIGURE 9 shows a rotor blade detail for the engine embodied in FIGURE 7; and
In FIGURE 1, the rotor drum 1 according to the in- -vention has end flanges 2 and 3. End flange 2 carries the output shaft 4 and also serves as a supercharger impeller. The holes 5 drilled radially through the end flange 2 are connected to the main drum aperture 6 by holes 11. Rod bolts, studs and nuts or capscrews or other suitable fasteners, assemble end flanges 2 and 3 to the rotor 1. The vanes or blades 7 not being shown, for clarity. On the outer surface of end flange 3 the cooling fins 8 act as a cooling air impeller within the stator manifold or stator end shield 23.
In my engine the lubricating oil is mixed with the fuel initially if liquid fuel is used. Engines using gaseous fuels are lubricated by means of drip feeding into the combustion air inlet. Very large engines are pressure lubricated by means known in the art.
In FIGURE 2, the carburetor, not shown, fits externally on flange 9, so that the air entering through the centre aperture 6 of the rotor is suitably carburetted. This air-tuel-lubricant mixture enters end flange 2 by holes 11, and is centrifugally compressed into manifold chamber 12.
The manifold chamber 12, in end casing 13, connects by way of port 14 to the admission port 15 of the stator casing central section 16, as shown in FIGURES 2 and 3. For ease of fabrication the admission port 15, adjacent transfer port 14, is closed by a removable cover 17.
In the present embodiment rotor blades or vanes of different forms are shown.
As the rotor rotates, the blades or vanes 7, 7' reciprocate within the slotted recesses 19, 19' with rubbing contact or with mixed rubbing-rolling contact, if friction reducing rollers are bearing the vanes inside the recesses 19, 19. The rollers, not shown for clarity, are protected and sealed by means of seal strips, similar to seal strips 20 in FIGURE 6a, but not shown for clarity; the seal strips in recesses 19, 19' also prevent the leakage of gases through slots 18 in FIGURE 7. The velocity of motion for the side contact areas of the vane blades 7, 7' against the recessed end flanges is much lower than in the prior art. Also the transverse support afforded by the shoulders is provided for vane side sealing contact.
running clearance between the rotor end flange and the of the slotted recesses to the blade, to resist gas loading normal to the blade surface, reduces the bending stresses produced thereby. As shown in FIGURE 6a, seal strips in the rotor structure act as gas seals 20 and replaceable rubbing surfaces. The holes 11 permit cooling air or combustible mixture through the rotor. .In the rotor of FIGURE 6, 6a and 6b, the rotor end flanges are of sensibly the same diameter as the rotor drum. The recessed end plates do not afford that vane support which the larger diameter embodiments aiford. Also the vanes or blades require to be sealed for sliding motion against the sides of the stator end closure. Consequently friction losses are greater, fluid sealing is not as effective and relatively lower compression ratios are advisable. The advantage of such a rotor structure lies in its simplicity and cheapness, for use in engines where initial cost is the prime factor, and efiiciency and economy are of reduced significance, such as model engines, power mowers, emergency stand by power plants etc.
In the structure of FIGURE 6 the reduced diameter rotor end flanges required to be recessed into the end covers of the stator centre section, as shown in FIGURE 6b. Thus a flash surface for the vane ends extending from the rotor recesses over the stator end cover faces The annular stator end cover recess requires a gas seal 2-1 of suitable type at each end of the I'OIOI.
A proposed further refinement includes the use of blade supporting rollers within the rotor 1 blade or vane recesses, mounted in a location axial and parallel adjacent to the seal strips 20 of FIGURE 6a, to ensure minimum friction forces acting against free blade movement, but not shown for clarity.
. The vane bearing rollers, the vane guide rollers and the rotor main bearings previously disclosed may be semi-permanently lubricated with various suitable greases such as the molybedenum disulphide greases, well known in the art, 'or they may be included into-the general lubrication system, by one of the known means of pressure or drip lubrication.
Rotor blades or vanes of various types may be incorporated in the engine, using light springs or gas pres sure for radial outward force, or relying on centrifugal force, or relying on a combination of said vane control means. The vanes may also be inter-connected by levers or by means of small pistons in suitable bores, being in communication with each other and achieving controlled vane movement.
A further refinement to assure correct vane movement at very low revolutions, is the internal vane control cam 35 in FIGURE 8.
A further embodiment using rollers is disclosed below.
Generally, composite vane blades made of two facing sections as shown in FIGURE 6 and 6a are found very suitable and in the simple embodiment having reduced diameter end plates, as shown in FIGURE 6b, where vane sealing contact against the stator end walls is necessary, the use of a spring means producing radial and axial reaction forces between the facing vane blade halves ensures that requisite sealing pressure is exerted by the blades.
These profiled and laminated vanes, as shown in FIGURE 6a, afford the advantages of lighter weight and greater strength and they distribute the vane Weight over' a multitude of contact lines to the stator bore, thus achieving better sealing and less wear.
In construction of such vane blades it is necessary to prevent gas leakage between the adjacent facing blade surfaces, and this is achieved by a variety of methods obvious to one skilled in the art such as interdigitated radial lands or prorninences forming a gland effect, or heat resistant plastic or other suitable sealing strips of varying materials and sections.
It has been found that many combinations of materials are suitable for the stator and rotor components, where rubbing contact occurs. The use of work hardening stainless steels is to be avoided, as breakage and possible galling can occur. Combinations of molybdenum alloy steels with cast iron, high carbon steels with nodular iron and metal-plastic compounds and certain aluminium alloys have been found effective, and suitable selection presents no difliculty to one skilled in the art.
The external cooling air circuit is formed of intake ports 22 admitting air to the impeller blades 8 of the rotor. As shown in FIGURES 2, 4, 5 and 8, the air is induced into the cooling manifold 23 of the end cover and passes, via the holes 24 in the flange 25 to the remainder of cooling manifold 23 located around the central stator casing where it is directed on to the peripheral outer surface of the stator. The holes 24 are peripherally arranged on the flange 25, and are graduated in size to give controlled cooling and to minimize thermal distortion. The annular cover strip 26 is used for ease of fabrication and assembly, as the stator casing 16 may then be successfully cast by simple techniques.
The rotor 1 is supported in the three piece stator by an appropriate arrangement of bearings, such as roller, ball or journal.
In the embodiment of FIGURE 7, the radial position of the rotor blades 7' is controlled by cam rings 27 and 28, operating against rollers 22 and 30.
In this fashion the wear of the rotor blades is minimised or prevented, as the force to position the blades radially in their slots is provided by rollers 29 reacting against cam rings 28, and rollers 30 reacting against cam rings 27.
In this embodiment the blades can be arranged to have a slight radial clearance, thereby obviating blade tip wear. Sealing is achieved by means of seal strips 28 of FIGS. 9 and 10.
A further refinement to reduce friction and to minimise wear of the vane blade sides, recessed into the vane guide recesses 19, FIGURE 1, and 19', FIGURE 7,- is given by using rollers to carry the vanes in said vane guide recesses. Thus, the vanes do not actually touch the shoulders of recesses 19 or 19', but the rollers only. Rollers not shown for clarity. The use of these rollers makes sealing of recesses 19' in FIGURE 7 necessary, to prevent gas leakage through slots 18. The sealing strips for the recesses are similar in shape and principle as seal strip 20 in FIGURE 6a.
Ignition is initiated by the spark plug or glow plug 31, in housing 32, connected to the combustion zone by connecting apertures 33. The ignition system is not shown, but as timing is not necessary, a continuous spark from an oscillator or trembler coil may be used to initiate combustion, or if a glow plug is applied, an electric current from any source may be used.
Operation of the engine, with particularreference to FIGURE 3 is as follows:
Clockwise rotation of the rotor induces air, oil and fuel mixture into the space A. Rotation past inlet port 15 seals the space A, and further rotation causes the mixture to compress, as at B. As the leading blade or vane uncovers the first aperture 33, ignition occurs, either from spark or glow plug 31, or by flash-back from the combustion in the preceding space. Continued rotation is now produced by the working stroke, as the gas expands, such as in zones C and D. Finally the expanded gas in zone E passes from exhaust port 34 to atmosphere.
In the embodiment of FIGURE 8 a stationary mixture guide and vane control device 37 conveys the combustible mixture from the carburetor, through the centre of the rotor, out of the mixture guide by ports 36, past the vane control cam 35 and so into the supercharger entry ports 11. The vane control cam 35 assures proper vane movement at low speed, when centrifugal forces are insufiicient' to keep the vanes in constant contact with the stator bore.
Starting may be effected by electric starter, hand crank starter or by admitting compressed air or combustion products from a previous run stored in a suitable container, to the expansion zone D FIGURE 3, by a nonreturn valve, not shown, or any other known means of starting an engine.
Because of the simplified structure used, quite large engines are feasible. The cooling effect of the air fuel mixture flowing through the rotor, combined with the regulated stator temperature and the flash-back ignition through apertures 33 permits the use of lower octane and very heavy fuels.
Thermodynamic efficiency is promoted by the use of higher compression ratios, and the overall thermodynamic heat balance is greatly improved by using live mixture for rotor cooling. Because of the large number of Working strokes per revolution being equal to the number of vanes on the rotor, the torque curve is very flat. In view of the symmetry of .the engine and the very low oscillating mass of the rotor blades, engine speeds are in the normal range for reciprocating engines. The simple methods of construction and absence of sophisti cated parts reduce manufacturing and assembly costs and the multi-blade rotor design results in a very high power to weight ratio.
It has been found that the flash-back ignition duct enables the spark or glow plug to be disconnected during steady running, and the passage of hot gases through the duct maintains the spark plug in clean condition and free of the oiling up often associated with oil-in-fuel running. It has also been found that passage of hot gases from the preceding firing space back through the ignition flashback duct usefully boosts the maximum gas pressure at the instant of firing.
Part of the high pressure gas in space C is permitted to escape from this space through the duct 33 to space D. At the instant of ignition and the following high pressure in space C, the exposed areas of the two vanes forming this space, are almost in equilibrium and useful work in this area is not possible. However, part of the peak pressure flows through duct 33 to space D. Thus the pressure is here built up, and as the leading surface area of exposed vane at that instant has a favourable ratio to the trailing vanes exposed area, an increase in effective torque and work is obtained.
It is evident that the improved rotor structures may be used with or without the flash-back duct. The disclosure throughout has been directed to radially directed blades or vanes, but variations from the radial direction do not in themselves constitute distinction over the improvements disclosed herein.
What I claim is:
1. A rotary sliding vane engine having an engine housing with a peripheral wall having a symmetrical elliptical shaped inner surface and a pair of axially spaced end walls, a rotor mounted for rotation about a fixed axis at the intersection of the major and minor axes of said elliptical surface, said rotor having a pair of axially spaced end flanges of greater diameter than the major diameter of said elliptical surface and a hollow drum intermediate and fixed to said end flanges, axially extending slots in said drum, radially extending grooves in said end flanges aligned with said slots, sliding vanes carried by said rotor in said slots, with-the ends of said vanes extending into said grooves in said end flanges, said vanes co-operating with the inner housing surface to form a plurality of expansible chambers, means in said housing on opposite sides of one end of said minor axis communicating with said expansible chambers to supply combustible mixture to, and exhaust combustion products from said expansible chambers, axle means journalled in said engine housing and extending along rotor, said rotor axis and attached to said one end of said axle ending at the engine housing outer surface and being hollow and communicating with the inside of said drum to form an axial air intake, means on said housing for securing a carburetor to said air intake, radially arranged passages in one of said end flanges, passage means communicating said radial passages to the hollow interior of said drum, the radially outer ends of said radial passages opening to a fluid receiving chamber in said engine housing, means communicating said fluid receiving chamber to said supply means, impeller means mounted on the face of the other of said end flanges remote from said hollow drum, means in said engine housing adjacent said impeller forming a chamber for receiving fluid from said impeller, and passages in said peripheral wall for directing fluid from said impeller fluid receiving chamber to cool said housing wall, and ignition means adjacent said other end of said minor axis on the same side as said exhaust means and communicating with said expansible chambers as they move past said ignition.
2. Apparatus as in claim 1 further having an ignition means for sustaining combustion in succeeding adjacent zones comprising two apertures angularly displaced in said peripheral wall forming a communicating way for fluid flow between adjacent separate zones at the instant of passage of one of said sliding vanes between said apertures, whereby combustion in a first zone may initiate combustion in the adjacent succeeding zone.
3. Apparatus as in claim 1, wherein the ignition means is a spark plug.
4. Apparatus as in claim 1, wherein the ignition means is a glow plug.
5. Apparatus as in claim 1 wherein the ignition means includes flash-back apertures in said stator casing.
6. Apparatus as in claim 5 further having radially directed vane recesses, vane locating guide means, a first means for initiating ignition, a second means for continu ing ignition and means for admitting combustible products to said engine and exhausting products of combustion from said engine, said second means consisting of a pair of interconnected apertures opening to said peripheral wall at spaced points one on each side of a vane during traverse thereof past the aperture openings.
7. In a rotary machine according to claim 1 and having a bore of elliptical form with a major and minor axis, rotary vane means mounted for rotation about a fixed axis and slidably supported to maintain contact with the internal surface of said elliptical bore by guide means including two rotor end flanges having a diameter greater than said major axis and recessed ways to guide the ends of said rotary vanes for their entire depth, sealing means to isolate the rotationally variable spaces circumscribed by said blades between said rotor flanges and said bore surface, sealing means in the recessed inner faces of said rotor end flanges to seal the small gap between inner rotor end plate faces against the end faces of the stator and means for admitting fluid to and delivering fluid from said variable spaces, during part of said rotation.
8. A rotary sliding vane engine according to claim 1, and having a symmetrical elliptical shaped stator and a rotor supporting sliding vanes for rotary and radial motion, said rotor having a pair of opposed end plates, of greater diameter than the major diameter of the elliptical bore of the stator, said end plates being internally recessed with radial ways to support, guide and seal said sliding vanes, circumferential rabbeted seats to accommodate peripheral floating seals between rotor and stator faces, said rotor end plates being of larger diameter than the major axis of the elliptical bore-forming rotating bounds for the stator bore sealed by means of floating periphery face seals.
9. In a sliding vane engine according to claim 1 first fluid compressing means, second means in series fluid flow arrangement with said first means to further compress said fluid, and third means compressing fluid to cool said second means.
(References on following page) 7 8 References Cited by the Examiner FOREIGN PATENTS 58,964 12/ 1953 France. UNITED STATES PATENTS A d dition to 978,559)
2 190 Chum 424,020 3/ 1911 France. 550,353 12/1912 France. 4/1907 Pwssen 716,754 10/1931 France. 11/1913 Ruhlmann- 754,461 8/1933 France.
5/1919 Vogan 1238 12 1940 Maurer et 1 123 3 SAMUEL LEVINE, Primary Examiner. 11/1942 Rhine 1238 10 JOSEPH H. BRANSON, 111., KARL J. ALBRECHT,
1/1960 Bush. Examiners-