Rotary expansible chamber devices – Heat exchange or non-working fluid lubricating or sealing – Non-working fluid passage in inner working or reacting member
Reexamination Certificate
2000-05-04
2002-04-09
Vrablik, John J. (Department: 3748)
Rotary expansible chamber devices
Heat exchange or non-working fluid lubricating or sealing
Non-working fluid passage in inner working or reacting member
C418S138000, C418S141000
Reexamination Certificate
active
06368089
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to pressure fluid machines of the rotary kind in general, and more particularly to machines of this type that incorporate orbiting blades.
2. Description of the Related Art
There are already known various constructions of machines that will be collectively referred to herein as pressure fluid machines, that is machines that either compress or pump gases or liquids (generally referred to herein as pumps), or are powered either by pressurized or by expanding, combusting, exploding or otherwise chemically reacting fluids (generally referred to herein as engines). The term “pumps” as used here includes those machines that compress or otherwise impart potential or kinetic energy to fluids, be they compressors, blowers or actual pumps, while the term “engines” stands not only for those of the steam or internal combustion varieties but also for other fluid-powered machines that are ordinarily called motors or drives. Among the heretofore proposed pressure fluid machines, there are also those of the rotary type, that is those including rotors mounted for rotation in respective internal chambers of associated stators or housings.
Some rotors of such rotary engines or pumps include blades that orbit associated axes within the respective internal chambers, being ordinarily in frictional contact at their outer peripheral end faces with the surfaces bounding such chambers. Typically, in a machine of this type, the aforementioned axis is that of the internal chamber and also of a torque-transmitting (i.e. input or output, as the case may be) shaft traversing such chamber, and the rotor includes, besides the blades, a body that is mounted on the housing for eccentric turning or rotational movement about and relative to this axis or shaft and serves as a carrier or entrainment member for the blades. A known representative of this approach is to be found in the publication
Grundzüge der Theorie und des Baues der Dampfturbinen mit der Berücksichtigung der Rotationsdmapfmaschinen,
by Peter Stierstorfer, Leipzig, Germany (1904), in which page 139 reveals a so-called “Patschke” rotary steam engine. Its structure is characterized in that one of its blades is rigidly connected with the central shaft which thus becomes torque-transmitting in that the torque imparted to it by the one blade is transmitted thereby to the exterior of the engine and ultimately to a part or parts driven by this torque. In the course of the rotation of the rotor, the orbiting blade is retracted into or extended out of an associated opening provided for it in the entraining rotor member or body; this has for its consequence alternating changes in the working radius of this orbiting blade and simultaneously the latter is accelerated and subsequently decelerated during each rotation, depending on the angular position about the central axis at which it is situated at any particular time. Simultaneously with and as a direct consequence of the increase and decrease in the circumferential speed of the orbiting blade, even the speed of the torque-transmitting shaft varies accordingly in the course of the respective revolution, owing to the rigid connection of the one orbiting blade with the shaft. This causes non-uniform rotation and pulsation of this shaft. When the torque-transmitting shaft is subsequently subjected to an additional torque of, for instance, a drive machine and/or a driven wheel of a mobile machine, and/or by a simple increase in the energy level of the supplied medium in an expansion motor, or during the transmission of high compression ratios of the fluid media being pressurized in compressors, there is encountered an excessively high stressing at the region of the rigid connection between the orbiting blade and the torque-transmitting shaft. This disadvantageous repetitive stressing results in relatively high incidence of damage to the machine, reduces its useful life, and requires the performance of an arduous process in the selection of suitable materials.
Another known implementation of a rotary machine with orbiting blades involves loose accommodation of such blades in radial recesses formed at the outer periphery of the eccentrically mounted rotor body. This solution exhibits a plethora of disadvantages stemming basically from the fact that the centrifugal forces acting on the individual blades increase with increasing rotational speed of the rotor. As a result, the force with which each of them presses against the surface circumferentially bounding the internal chamber of the stator increases as well, and the frictional losses of the pressure fluid machine increase disproportionately. Then, there exists a limit on the rotational speed of the rotor for the machine to be able to perform its function, and when this limit is exceeded, the encountered friction forces consume all of the input energy and the machine rotor rotation is retarded up to the point of ceasing altogether. A further disadvantage of this solution is to be seen in the fact that there is merely a line contact between the outer peripheral surface of the respective orbiting blade and its counterpart on the stator, inasmuch as the orbiting blades are centered not on the central axis of the cylindrical working space or chamber of the stator, but rather on the axis of the eccentrically mounted rotor that is transversely offset from the central axis; this limits the use of the machine of this construction to just as a compressor.
Another technical solution that has a pronounced bearing on the present invention is disclosed in the European patent EP 0 102 555. This machine includes a hollow cylindrical stator housing in the interior of which there is eccentrically mounted a rotor body; the latter has mounted thereon, at its outer periphery, respective cylindrical guiding members for free turning relative to the rotor body about respective axes extending parallel to the central axis of the internal chamber of the chamber. A pivot axle centered on this axis is immovable relative to the stator housing. Orbiting blades pass through the respective guiding members to cooperate with the inner surface of the cylindrical stator housing. These blades extend substantially radially with respect to the central pivot axle, and their radial distance is adjustable by means of connecting rods that are rotatably supported on the central pivot axle.
Disadvantages of this solution are to be seen primarily in the existence of tilting moments arising as a consequence of asymmetrical support of the connecting rods on the central pivot axle, and in their implementation with an adjustable feature, which involves technical complexity and, in the event of thermal loading, low resistance to deformations. Another persisting drawback exists at the sealing locations, which are problematical especially at the interfaces between the orbiting blades and the rotor body, and between the outer peripheral surfaces of the blades and the inner surface bounding the internal chamber of the cylindrical stator housing. It is also necessary to offset the axial termination of the rotating part or rotor body from the corresponding portion of the stator housing facing the same, and a high gradient of the pressure medium exists at this region, with attendant high losses of such medium. Last but not least, the cantilevered mounting of the central pivot axle detracts from the mechanical stability of the machine.
Generally applicable disadvantages of the heretofore known rotary machine systems with orbiting blades include the existence of considerable frictional forces both between the orbiting blades and the rotor body and between the orbiting blades and the stator housing, as well as the existence of high material stresses at the connection locations of the orbiting blades and the torque-transmitting shaft. When the orbiting blades are loosely supported on the rotor body, frictional forces that are significantly increased with increasing speed of rotation are encountered even at the contact surface of the orbit
Ruzek Peter R.
Vrablik John J.
LandOfFree
Orbiting blade rotary machine does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Orbiting blade rotary machine, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Orbiting blade rotary machine will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2891836