1. A FLUID-OPERATED MOTOR COMPRISING A CASING HAVING A GENERALLY CYLINDRICAL INSIDE WALL SURFACE, A ROTOR MOUNTED IN SAID CASING AND HAVING A CONTINUOUS SERIES OF IDENTICAL SUCCESSIVELY LONGITUDINALLY EXTENDING ASYMMETRICAL PERIPHERAL RIBS, EACH RIB HAVING A RELATIVELY STEEP FORWARD WALL SURFACE AND A GRADUALLY SLOPING REAR WALL SURFACE WITH A CORNER PORTION BETWEEN SAID FORWARD AND REAR WALL SURFACES, AN INLET CONDUIT CONNECTED TO THE CASING, AN OUTLET CONDUIT CONNECTED TO THE CASING ADJACENT SAID INLET CONDUIT, THE INSIDE SURFACE OF THE CASING BETWEEN THE CONDUIT BEING ARCUATE AND SUBSTANTIALLY COAXIAL WITH THE ROTOR AND BEING SUBSTANTIALLY SEALINGLY ENGAGED BY THE CORNER PORTIONS OF THE RIBS, THE ROTOR BEING ECCENTRICALLY LOCATED IN THE CASING TO DEFINE A WORKING SPACE BETWEEN THE ROTOR AND THE CASING WHICH INCREASES IN RADIAL WIDTH FROM THE END THEREOF COMMUNICATING WITH THE INTAKE CONDUIT TO THE END THEREOF COMMUNICATING WITH THE OUTLET CONDUIT, THE INLET CONDUIT BEING FORMED WITH A RESTRICTED VENTURI THROAT PORTION ADJACENT ITS CONNECTION WITH THE INTERIOR OF THE CASING, AND THE CORNER PORTION BETWEEN THE FORWARD AND REAR WALL SURFACES OF THE RIBS AND THE CYLINDRICAL INSIDE WALL SURFACE OF THE CASING RESPECTIVELY DEFINING GENERALLY SIMILAR RESTRICTED VENTURI THROAT PORTIONS.
Oct. 18, 1966 E. KRZYSZCZUK 3,279,750
DIFFUSION MOTOR Filed Feb. 4, 1966 2 SheetsSheet 1 INVENTOR.
E. KRZYSZCZUK DIFFUSION MOTOR Oct. 18, 1966 2 Sheets-Sheet 2 Filed Feb. 4, 1966 INVENTOR EOW40 L IQZ Y5 Z CZ (/16,
United States Patent 3,279,750 DHFUSION MOTOR Edward Krzyszczuk, 1352 N. St- Louis Ave., Chicago, 11]. Filed Feb. 4, 1966, Ser. No. 525,035 Claims. Cl. 253-40) This invention relates to fluid pressure-operated motor devices, and more particularly to an improved compressed air motor of the rotary type.
The main object of the invention is to provide a novel and improved fluid-operated motor of the rotary type, said mot-or being simple in construction, having high efficiency over a wide range of motor speeds, being operable over a wide range of temperatures, and being especially useful under conditions .of variable loading and driving speeds.
A further object of the invention is to provide an improved compressed air-driven motor which is inexpensive to manufacture, which is durable in construction, which is economical to operate, and which has a minimum number of parts so that it is easy to maintain in operating condition.
Further objects and advantages of the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:
FIGURE 1 is a side elevational view of an improved fluid pressure-operated motor constructed in accordance with the present invention.
FIGURE 2 is an enlarged transverse cross-sectional view taken substantially on the line 22 of FIGURE 1.
FIGURE 3 is a longitudinal vertical cross-sectional view taken substantially on the line 33 of FIGURE 2.
FIGURE 4 is a graph showing the changes in fluid pressure and fluid velocity of the working fluid as it passes around the interior of the working chamber of the motor of FIGURES l to 3 from intake to exhaust.
FIGURE 5 is a fragmentary developed diagram of the portion of the working fluid space adjacent to the fluid intake passage of the motor of FIGURES 1 to 3, showing the paths of movement of fluid particles as they pass through successive diffuser and nozzle sections defined between the rotor and the inside wall surface of the casing of the motor.
Referring to the drawings, 11 generally designates an improved circular flow fluid pressure-operated diffusion motor constructed in accordance with the present invention. The motor 11 comprises a generally annular casing 12 which may be secured in any suitable manner to a stationary support, the casing 12 being provided with the cylindrical peripheral wall 13 and the transverse end wall 14. The casing is provided with an opposite end wall consisting of a circular cover 15 having an externally threaded peripheral flange 16 which is threadedly engaged in an outwardly offset rim flange 17 provided at the left end of the cylindrical wall 13, as viewed in FIGURE 3.
The motor shaft, designated at 18, is rotatably received in respective ball bearing assemblies 19 and 20 provided in oppositely directed annular bearing housings 21 and 22 integrally formed in wall 14 and cover 15.
Keyed on the shaft 18 inside housing 12 is a rotor 23, said rotor comprising the elongated axially 'extending inner sleeve portion 24 which receives shaft 18 and is secured thereto by a longitudinal key 25 received in a keyway recess 26 provided in shaft 18 and in a longitudinal keyway 27 provided in the bore of sleeve portion 24, as is clearly shown in FIGURE 3. The opposite ends of sleeve portion 24 are substantially in abutment with the respective inner raceways 28 and 29 of the ball bearing assemblies 20 and 19. Rotor 23 is formed with a thickened outer rim portion 31 connected to the midportion of sleeve member 24 by a transverse web 32. The
Patented Oct. 18, 1966 rim portion 31 is received substantially sealingly between but is freely rotatable relative to transverse wall 14 and cover plate 15, as shown in FIGURE 3.
Rim portion 31 is formed with successive asymmetrical ribs or lobes 33, each lobe having a relatively steep front wall portion 34 and a relatively gently inclined rear wall portion 35 connected with front wall portion 34 by a smoothly curved arcuate crest 36 having a relatively short radius of curvature. The inclined, relatively long rear wall portion 35 is also arcuately curved but has a relatively long radius of curvature, as compared with the radius of curvature of crest 36 and the relatively steep front wall portion 34. The lobes 33 are identical in contour and subtend equal angles from the axis of shaft 18 and are at equal radial distances therefrom.
The main wall 13 of casing 12 is integrally-formed with a fluid inlet conduit 37 and a fluid exhaust conduit 38 arranged substantially parallel to each other and spaced a short distance apart, as shown in FIGURE 2. The bore of the intake conduit 37 is formed with a constricted throat 39, defining a venturi nozzle at the region Where the driving fluid is injected into the casing 12, the nozzle communicating with the diverging nozzle 40 leading to the working space 41 between rotor 23 and the inside wall surface 42 of easing portion 13.
The working space 41 flares slightly in radial width in a counterclockwise direction, as viewed in FIGURE 2, providing successively increasing working fluid spaces between the inside surface 42 and the rotor lobes 33 in a counterclockwise direction, as viewed in FIGURE 2, namely, in the direction of rotation of rotor 23. Thus, the shaft 18 has its axis slightly offset in an upward direction, as viewed in FIGURE 2, from the central axis of the casing peripheral wall 13. The arcuate transition wall portion 44 between the bore 45 of exhaust conduit 38 and the discharge space 40 of intake conduit 37 is coaxial with rotor 23 so that the arcuately-curved lobe corners 36 are substantially in sealing contact with the arcuate transition surface 44 as the lobes pass from the exhaust conduit bore 45 to the intake space 40.
In operation, working pressure fluid, for example, compressed air, is admitted through conduit 37 and venturi throat portion 39 into the diverging nozzle 40 leading to the diffusion space 41 in casing 13. In entering the space 41 the compressed air suffers a drop in pressure from the initial static pressure P shown in FIGURE 4, along the pressure decrease line P while the velocity of the air builds up in the nozzle 39-40, as indicated by the ascending dotted line V in FIGURE 4, to a value represented by V The high velocity air then passes to the region adjacent the first adjacent smoothly rearwardly-sloping surface 35 of rotor 23, defining the first diffusion region, designated as DS in FIGURE 5. In this region the fluid pressure rises to a value P (shown in FIGURE 4) while the air velocity drops to a value V along the dotted line V in FIGURE 4. In moving through the first diffuser section DS the air stream is forced to change in direction of movement as Well as to diffuse, which creates an underpressure or vacuum in a region 47 adjacent to the sloping lobe surface 35, shown in FIGURE 5. Meanwhile, a maximum pressure P is achieved at the end of the diffuser section D8 which is applied against the steep front lobe surface 34 of the next lobe element 33. A venturi nozzle 48 is defined between the arcuately-curved corner 36 and the inside surface 42 in the region 48, providing a circumferential diffusion as the air passes through the venturi nozzle space 48 into the region adjacent the next sloping lobe surface 35, which creates another underpressure region 47. The pressure in the region 47' is designated as P in FIGURE 4. The difference in pressure be tween the values P developed immediately prior to the venturi nozzle region 48 and the minimum pressure value P is a working pressure, designated as P in FIGURE 4 which acts against the frontal lobe surface 34 and is effective to drive the rotor 23 under its load.
As the air pressure drops from the value P to the value P in FIGURE 4, the air velocity increases from the value V to the value V This occurs while the air is passing through the nozzle space 48, designated as N in FIGURE 4. As the air passes through the second diffusion space shown at B5 in FIGURE 5, the air pressure rises from the value P to the value P shown in FIG- URE 4, while the air velocity drops from the value V to the value V along the dotted line V When the fluid enters the next nozzle section, namely, the space defined between the rounded corner 36 of the next lobe 33 and the inside casing surface 42, shown at N8 in FIGURE 4, the fluid pressure again drops while passing through this nozzle section from the value P to the value P in FIGURE 4 and the fluid velocity increases from the value V to V followed by diffusion into the next working space, ultimately producing another build-up of fluid pressure and drop in fluid velocity, as shown by the pressure line 59 and the dotted velocity line Vg in FIG- URE 4.
Each cycle of diffusion and compression develops a working pulse which is applied to the rotor 23, the work ing pulses :being similar to those provided by the pressure difference values P in FIGURE 4.
Because of friction and turbulence losses, the successive maximum velocities developed as the fluid passes around the interior of the casing 13 diminishes. For example, the velocity V is lower than the velocity V,,, and the next maximum velocity V is lower than the previous maximum velocity V The difference between the peripheral velocity U of the rotor and the maximum fluid velocity V is the relative fluid velocity V,, shown in FIGURE 4. This is the usable working velocity.
The space 41 gradually increases in size in a counterclockwise direction, as above-mentioned, allowing the air to expand as it passes through its successive stages of diffusion and compression and as its velocity gradually decreases, until finally the spent air is discharged through the bore 45 of exhaust conduit 38.
It will be noted that the initial restricted venturi throat portion 39 in the intake conduit 37 is defined by a bulge or enlargement 60 in the outside wall of conduit 37, said bulge or enlargement 60 being in the form of a transverse rib having a convex surface whose radius of curvature is approximately the same as that of the arcuately curved corner portions 36 of ribs 33. The restricted venturi throat 39 is thus defined by the rib 60 and the opposing relatively gently arcuately curved opposite wall surface 61 of the fluid inlet conduit 37. The radius of curvature of wall 61 is approximately the same as the radius of curvature of the inside Wall 42 of casing 12.
It will be further noted that the median planes of the restricted venturi passage 48 change in direction around the arcuately curved corner portions 36 substantially by the angle subtended by said corner portions, producing a corresponding change in direction of the particles of air passing through said throat portions, such change in direction of air particles cooperating with the diffusion of the air in the manner above described to provide the regions 47, 47', 'etc., of relatively low pressure adjacent the surfaces 35.
While a specific embodiment of an improved fluidoperated motor has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.
What is claimed is:
1. A fluid-operated motor comprising a casing having a generally cylindrical inside wall surface, a rotor mounted in said casing and having a continuous series of identical successive longitudinally extending asymmetrical peripheral ribs, each rib having a relatively steep forward wall surface and a gradually sloping rear wall surface with a corner portion between said forward and rear wall surfaces, an inlet conduit connected to the casing, an outlet conduit connected to the casing adjacent said inlet conduit, the inside surface of the casing between the conduit being arcuate and substantially coaxial with the rotor and being substantially sealingly engaged by the corner portions of the ribs, the rotor being eccentrically located in the casing to define a working space between the rotor and the casing which increases in radial width from the end thereof communicating with the intake conduit to the end there-of communicating with the outlet conduit, the inlet conduit being formed with a restricted venturi throat portion adjacent its connection with the interior of the casing, and the corner portion between the forward and rear wall surfaces of the ribs and the cylindrical inside wall surface of the casing respectively defining generally similar restricted venturi throat portions.
2. The fluid-operated motor of claim 1, and wherein said corner portion between the relatively steep forward wall surfaces and the gradually sloping rear wall surfaces are arcuately rounded.
3. The fluid-operated motor of claim 2, and wherein said sloping rear wall surfaces are arcuately rounded and have relatively large radii of curvature.
4. The fluid-operated motor of claim 3, and wherein said relatively steep forward wall surfaces smoothly merge with said arcuately rounded corner portions.
5. The fluid-operated motor of claim 4, and wherein said inlet conduit and outlet conduit are substantially parallel.
6. The fluid-operated motor of claim 5, and wherein said rotor comprises a shaft rotatably journalled longitudinally in the casing with its axis parallel to the axis of said generally cylindrical inside wall surface, a sleevelike body secured on said shaft, a generally cylindrical rim and a transverse web connecting said rim to the intermediate portion of said sleeve-like body, said ribs being formed on the peripheral outer portion of said rim.
7. The fluid-operated motor of claim 6, and wherein the casing includes front and rear transverse wall elements, said rim being received rotatably and substantially sealingly between said transverse wall elements.
8. The fluid-operated motor of claim 1, whereinthe restricted venturi throat portion in the inlet conduit comprises an inwardly projecting convex transverse rib formed in the outer wall of the inlet conduit, said convex rib being spaced from the inner wall of the inlet conduit.
9. The fluid-operated motor of claim 8, and wherein said convex rib and the corner portions of the peripheral ribs of the rotor have approximately the same radii of curvature.
10. The fluid-operated motor of claim 9, and wherein the inner wall of the inlet conduit opposing said convex rib is concave and has approximately the same radius of curvature as the inside casing wall surface opposing the peripheral ribs of the rotor.
References Cited by the Examiner UNITED STATES PATENTS 2,230,545 2/1941 Root 253-432 3,197,176 7/1965 Brunel et a1. 253-40 X FOREIGN PATENTS 909,689 l/1946 France. 545,397 5/ 1942 Great Britain. 411,152 7/ 1945 Italy.
MARTIN P. SCHWADRON, Primary Examiner. E. A. POWELL, IR., Assistant Examiner.