Claims
- 1. In an external parallel axis rotary piston blower working in mating engagement, having improvements in combination therewith comprising:
- a casing having two inner cylindrical surfaces that intersect each other, an inlet and an outlet in a region of the intersections of these inner cylindrical surfaces such that inlet and outlet flow of a working gas is undisturbed and uniform without being turbulent therein, two side plates and two shafts vertically thereof counter-rotating with equal velocity;
- identically shaped rotary pistons on said shafts respectively rigidly connected therewith, said rotary pistons each being formed by two coaxial semi-cylinders having different radii including a semi-cylinder of larger radius and a semi-cylinder of small radius, of which the semi-cylinder with the large radius also has a portion with a plane having a length greater than twice the small radius and smaller than twice the larger radius that extending from the axis of the shaft toward the inner cylindrical surface of the casing and has a portion with outer large radius cylindrical surfaces thereof that move progressively along the respective casing inner cylindrical surfaces and also move progressively along the cylindrical surfaces of the semi-cylinders with the small radius of the other rotary piston, respectively; and
- transition surfaces on each of said rotary pistons formed on the semi-cylinder with a large radius; said transition surfaces being disposed at an angular offset direction relative to and beginning at corners of said transition surfaces that cooperate with the corresponding transition surfaces of the other rotary piston and that collectively with the casing inner cylindrical surface, the side plates and the cylindrical surfaces of the semi-cylindrical with the small radius form working chambers to allow variable volume therewith accompanied by the flow of the working gas that is undisturbed and uniform without being turbulent via slanting of the piston through outer mating surfaces including said transition surfaces disposed at the angular offset direction,
- the rotary pistons at axial sides thereof have disks, which with peripheral surfaces thereof operate with a seal radially between said disks and recesses in the wall of the side plates having a close gap relationship free of contact in a region of the casing and disks where heat expansion is identical and consequently negligible, said semi-cylinder with the large radius having recesses therein for balancing of the rotary pistons relative to each other.
- 2. A rotary piston blower in combination according to claim 1, in which the radii of said semi-cylinders have a ratio of 2.5 to 2.8 with respect to each other.
- 3. A rotary piston blower in combination according to claim 1, in which each of the pistons has a plane of symmetry of rotary piston sides such that the cylindrical surface of the semi-cylinder with the large radius terminates in said angular offset direction at an angle of 15.degree. to 25.degree. relative to a base surface of said large-radius semi-cylinder and in a direction with an angle of 30.degree. relative to the plane of symmetry of the rotary piston sides thereof.
- 4. A rotary piston blower in combination according to claim 3, in which each semi-cylinder has flanks including axial sides therewith and a base surface therewith as well as a corner between said flanks and said base surface, said corner being rounded along an external radius unit with which the mating surfaces roll off relative to each other.
- 5. A rotary piston blower in combination according to claim 3, in which edge locations of the semi-cylindrical surface of the semi-cylinder with the small radius exist that coincide in the mating engagement for a transitional relationship in corresponding position relative to the base surface of the semi-cylinder with the large radius relative to each other.
- 6. A rotary piston blower in combination according to claim 1, in which shafts of the rotary pistons are unitary with the semi-cylinder with the small radius and project laterally therefrom relative to recessing complementary thereto in said casing.
- 7. A rotary piston blower in combination according to claim 6, in which the rotary pistons movable in the casing operate along the walls of the side plate and conform to complement the rotary pistons relative to the side plate respectively laterally as to each other continuously having the close gap relationship therewith.
Priority Claims (1)
| Number |
Date |
Country |
Kind |
| 3340202 |
Nov 1983 |
DEX |
|
BACKGROUND OF THE INVENTION
This application is a continuation application of Ser. No. 667,952 filed Nov. 2, 1984, now abandoned.
The present invention relates to a parallel and external-axial rotary piston blower machine having a cocoon-shaped cross section with two arcuate segmental rotors operating in meshing engagement with inner cylindrical surfaces or internal curved surfaces of a machine casing or enclosed rotary piston blower housing. The rotary piston blower housing includes a casing in the form of housing plate elements or side plates having two cylindrical internal curved surfaces or inner cylindrical surfaces that intersect each other, being identical in shape reciprocally, as well as having an inlet and an outlet in the region of the intersections or meshing lines of these inner cylindrical surfaces or internal curved surfaces. The rotary piston blower housing also has two side plates or housing plate elements that have two shafts journaled thereby counter rotating with equal angular velocity coaxially relative to the internal curved surfaces or inner cylindrical surfaces located vertically thereof. Identically shaped rotary pistons on the shafts, mutually rigidly connected therewith, rotate thereon. The rotary pistons, each being formed by two coaxial semicylinders have different large and small radii. The semicylinders have base surfaces thereof against each other. The semicylinder with a large radius has the cylindrical surfaces thereof then beginning to run along the respective internal curved surfaces generally described as inner cylindrical surfaces and along the cylindrical surfaces of the semicylinders with the small radius of the other rotary piston, when coming out of engagement with the internal curved surface generally described as an inner cylindrical surface. Transition surfaces are formed thereby between the semicylinder with the large radius and the semicylinder with the small radius. These transition surfaces mesh or dovetail with the corresponding transition surfaces of the other rotary piston and together with the internal curved surface or inner cylindrical surface, the side parts and the cylindrical surfaces of the semicylinder with the small radius form operating or working chambers having variable volume therewith.
1. Field of the Invention
Such machines can be compressors operating as pumps or as counter valves or blowers or superchargers operating only counter to a pressure chamber. These machines have the advantage that very long sealing paths exist between the rotary piston blower housing or casing and the semicylinder with the larger radius on the one hand and the end surfaces of the rotary piston on the other hand. Furthermore a linear, though sealing, limit or boundary is formed by surfaces running up tangentially against each other between cylindrical surfaces rolling-off and gliding against each other.
2. Description of the Prior Art
German Offenlegungsschrift 20 61 567 discloses an initially described machine functioning as a compressor operating counter to or against a rotary slide valve controlled via the synchronizing gear of the machine. The transitions from the cylindrical surfaces with large radius to the cylindrical surfaces with small radius are constructed as teeth surfaces or flanks of a tooth that engage relative to each other so that this machine operates like a gear pump with large gaps between teeth.
This machine must be very well sealed-off in order to reach the desired sealing effects, resulting from the compression ratios represented in the drawings. The machine accordingly must start up with an oil film directly on the cylinder wall of the housing and the side walls thereof and likewise the cylinder surfaces of the rotary pistons must roll off directly with a sufficient oil film because of the sliding engagement therewith. The teeth surfaces or flanks of a tooth of the transitions between the cylinder surfaces also must slide off connected or force-looking against each other. Consequently, very large frictional resistances must be overcome and the machine cannot run or operate free of oil or with higher speeds. The working or operating gas must be conveyed at the inlet and the outlet around an edge generating a very acute-angular turbulence or whirl between the inlet passage and the cylindrical housing wall, whereby the part of the one piston having the large radius lies respectively before the inlet and the outlet and the flow path is considerably narrowed or restricted thereby. Furthermore, compressive flows consuming capacity to a high extent as known for geared pumps, as well as gas enclosures being intensely or strongly compressed, result during engagement of the transition surfaces between each other, so that this machine is very unfavorable as to flow technology. Also, the operation counter to, or compared with, a valve results in an intermittent flow discharge causing strong or intense noises. The flow discharge additionally produces or generates longitudinal waves in the pressure line or conduit; such waves, for instance, would preclude the employment thereof as a charger for multi-cylinder combustion engines. Finally, such machines can supply no oil-free working or operating gas, since these machines must run with an oil film because of the direct advance of the moved parts thereof, which, in any case, considerably restricts or limits the possibilities of employment and utilization thereof.
An object of the present invention is to develop or evolve a machine of the aforementioned type as a blower or supercharger machine to be produced very simply and with very little cost. The machine has a high delivery rate with small structural size and with small or nominal drive capacity, as much as possible noiseless, silenced or low as to noise and quiet in operation and producing no disturbing pressure pulsations. The machine accordingly is well adapted and suited for the loading or charging of multi-cylinder internal combustion engines, for exhaust gas blowers or superchargers or as conveying blowers or superchargers for technical purposes.
These conditions or requirements could not be met or fulfilled previously, thus being satisfied only very inadequately by the previously known blowers or superchargers. The present inventive blower or supercharger machine fulfills such conditions or requirements in a surprising manner in the entirety thereof on the basis of structural features described in the following disclosure.
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| Number |
Date |
Country |
| 2021777 |
Dec 1971 |
DEX |
| 2061567 |
Jun 1972 |
DEX |
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Feb 1974 |
DEX |
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DEX |
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Continuations (1)
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Number |
Date |
Country |
| Parent |
667952 |
Nov 1984 |
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Patent Grant
4867659
