Circular Piston Internal Combustion Machine With Reduced Short Circuit Flow

Abstract

A circular piston internal combustion machine, in which conduit means lead into the interior of the machine between the inlet and outlet opening thereof and conveys gas pressure to the exhaust gas side into the gap between the piston and the adjacent mantle inner surface, said gas of higher pressure being withdrawn from a chamber section of the machine which has a higher pressure than prevails on the other side of said gap.

Description

The present invention relates to a circular piston internal combustion machine with a stationary mantle the inner mantle surface of which has the cross-sectional shape of a two-arc epitrochoid and together with side parts defines an inner chamber through which in a direction perpendicular to the side parts extends an eccentric shaft the eccentric of which has rotatably journaled thereon a triangular piston which at its corners has radial seals adapted to slide along the inner surface of the mantle and to form chambers with the mantle, said chambers increasing and decreasing in size during the rotation of the piston.

With this type of design, it is known in the mantle and/or the side parts to provide gas inlet and outlet passages the control openings of which are controlled by the piston. With this type of motors, that part of the working chamber which communicates with the inlet passage is by a saddle formation or lobe only incompletely separated from that part of the working chamber which communicates with the passage. Since, within the area of the outlet opening, there prevails primarily a higher pressure than within the area of the inlet opening, in the lobe area there forms a flow from the outlet side to the suction side. By the combustion chamber trough which generally is provided in the piston, the flow cross section for this flow is temporarily increased. The gas flowing to the suction side intermixes with the drawn-in air and thereby reduces the quantity of the fresh air load and consequently also reduces the motor power while simultaneously increasing the change temperature and thereby the tendency of the motor to knock.

It is, therefore, an object of the present invention to provide a rotary internal combustion machine which will overcome the above-mentioned drawbacks.

It is another object of this invention to provide a rotary internal combustion machine in which the gas flow from the discharge chamber via the lobe area into the inlet chamber, which gas flow is commonly termed short circuit flow, will be eliminated or at least be considerably reduced .

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawing, in which:

FIG. 1 is a longitudinal section through a circular piston internal combustion machine according to the invention with an inclined blowing in of the exhaust gas.

FIG. 2 is a longitudinal section of a twofold circular piston internal combustion machine according to the invention with inclined blowing in of exhaust gas.

The circular piston internal combustion machine according to the present invention is characterized primarily in that on the exhaust gas side between the exhaust outlet and the lobe area there is provided a passage in such a way that into the gap between the mantle and the piston and as the case may be, the combustion chamber trough, exhaust gas is blown in an inclined direction onto that part of the working chamber which is in communication with the discharge passage. In view of the direction of flow opposite to the short circuit flow of the gas, the short circuit flow is, as for as its quantity of flow is concerned, at least considerably reduced. The exhaust gas is withdrawn from an area of the machine where a higher pressure prevails than in the gap between the discharge passage and inlet passage. The passage opening toward the exhaust gas withdrawal is located on the exhaust gas side preferably in the housing part approximately removed from the opening of the inclined inblow by three-fourths of the length of the piston flank.

A further development of the present invention concerns a multiple circular piston internal combustion machine, The exhaust gas blown into the gap between the piston and the mantle into the discharge chamber of a machine unit is withdrawn from another machine unit. The passage opening toward the exhaust gas withdrawal is preferably spaced at a distance less than three-fourths of the length of the piston flank from the opening of the inclined inblow. This brings about the advantage that the opening for the withdrawal of exhaust gas will be so located that the course of the pressure in the expanding chamber from which the exhaust gas is being withdrawn will be affected only for a short period of time.

The passages for the gas being blown in at an incline may be provided with closing devices by means of which the gas supply at certain conditions of operation, for instance, during winter operation may at least partly be interrupted if temporarily higher temperatures of operation are desired.

An advantage of the blowing in of exhaust gas at an incline also consists in that due to the reduction of the short circuit flow, the time at which the inlet opens does no longer have to be determined with regard to the short circuit flow. By displacing the point "inlet openings" to an earlier time, the inlet opening may as to its cross section be dimensioned considerably greater whereby the filling will be improved and the power will be increased. Also an increase in the outlet opening will be possible in view of the above considerations.

Referring now to the drawing in detail, it will be noted that the triangular piston 2 moves along a two-arc epitrochoidal inner surface of the housing mantle 1. On the intersecting side at the intake side, there is provided an inlet passage 3, whereas on the exhaust gas side there is provided the outlet passage 4. Between inlet and outlet opening, the inner surface of the mantle has a saddle or lobe formation 5. Adjacent said lobe formation on the exhaust side there is provided a passage 6 which is arranged at an incline in the housing mantle in such a way that the gas blown out of said passage 6 flows at an angle with regard to the axis of the outlet passage 4 into the working chamber. The cross section of the said passage 6 decreases toward the opening 7 of the inclined blow-in passage. The withdrawal of exhaust gas through the passage 6 is effected at the opening 8 in the side part of the housing 1. The opening 8 is spaced from the opening 7 of the inclined blow-in passage by about three-fourths of the length of a piston flank. A valve 9 built into the passage 6 forms a closing device. Each of the flank surfaces of the rotary piston 2 may be provided with a trough-shaped portion 2a.

With the embodiment shown in FIG. 2, the passage 10 conveys exhaust gas from the opening 11 in the housing part of the motor unit 12 through the opening 13 in the housing mantle of the motor unit 14 to be blown in at an incline. Opening and direction of the passage at the blowing-in area 13 are designed as described in connection with FIG. 1. Passage 15 conveys the exhaust gas to be blown at an incline from the motor unit 14 to the motor unit 12 in a manner corresponding to the passage 10. The withdrawal of exhaust gas at 11 and 16 of the passages 10, 15 is spaced from the opening of the inclined blowing passages 13 and 17 at a distance which is less than the length of a piston flank.

It is, of course, to be understood that the present invention is, by no means, limited to the particular constructions shown in the drawings but also comprises any modifications within the scope of the appended claims.

Claims

What I claim is:

1. A circular piston internal combustion machine, which includes: mantle means, the inner cross-sectional surface of which has the shape of a two-arc epitrochoid with a first lobe and a second lobe located opposite to said first lobe, said member means associated with said mantle means and together therewith defining incompletely separated chamber means having gas inlet and outlet means on opposite sides of said first lobe, eccentric shaft means rotatably journalled in said side member means, rotary piston means of a spherical triangular cross-sectional shape rotatably supported by said eccentric shaft means, conduit means at least partially located in said mantle means between said inlet and said outlet means and leading into the interior of said mantle means while forming an angle with the plane passing through said first and second lobes for conveying a gas pressure from an area of higher pressure in said chamber means and heading into a gap formed by said piston means and said mantle means between said inlet and outlet means.

2. A circular piston internal combustion machine, which includes: mantle means, the inner cross-sectional surface of which has the shape of a two-arc epitrochoid with a first lobe and a second lobe located opposite to said first lobe, said member means associated with said mantle means and together therewith defining incompletely separated chamber means having gas inlet an outlet means on opposite sides of said first lobe, eccentric shaft means rotatably journaled in said side member means, rotary piston means of a Spherical triangular cross-sectional shape rotatably supported by said eccentric shaft means, conduit means at least partially located in said mantle means between said inlet and said outlet means and leading into the interior of said mantle means while forming an angle with the plane passing through said first and second lobes for conveying a gas pressure from an area of higher pressure in said chamber means and leading into a gap formed by said piston means and said mantle means between said inlet and outlet means, each of the flank surfaces of said rotary piston means being provided with a trough-shaped portion, and said conduit means leading into the interior of said mantle means in such a way that the gas jet entering the interior of said mantle means is directed into the respective adjacent trough.

3. A circular piston internal combustion machine, which includes: mantle means, the inner cross-sectional surface of which has the shape of a two-arc epitrochoid with a first lobe and a second lobe located opposite to said first lobe, said member means associated with said mantle means and together therewith defining incompletely separated chamber means having gas inlet and outlet means on opposite sides of said first lobe, eccentric shaft means rotatably journaled in said side member means, rotary piston means of a spherical triangular cross-sectional shape rotatably supported by said eccentric shaft means, conduit means at least partially located in said mantle means between said inlet and said outlet means and leading into the interior of said mantle means while forming an angle with the plane passing through said first and second lobes for conveying a gas pressure from an area of higher pressure in said chamber means and leading into a gap formed by said piston means and said mantle means between said inlet and outlet means, the mouth of said conduit means which leads to the area of lower pressure in the interior of said mantle means between said inlet and outlet means being spaced by approximately three-fourths of the length of a flank of said piston means from said area of higher pressure.

4. A circular piston internal combustion machine, which includes: mantle means, the inner cross-sectional surface of which has the shape of a two-arc epitrochoid with a first lobe and a second lobe located opposite to said first lobe, side member means associated with said mantle means and together therewith defining incompletely separated chamber means having gas inlet and outlet means on opposite sides of said first lobe, eccentric shaft means rotatably journaled in said side member means, rotary piston means of a spherical triangular cross-sectional shape rotatably supported by said eccentric shaft means, conduit means at least partially located in said mantle means between said inlet and said outlet means and leading into the interior of said mantle means while forming an angle with the plane passing through said first and second lobes for conveying a gas pressure from an area of higher pressure in said chamber means and leading into a gap formed by said piston means and said mantle means between said inlet and outlet means, said mantle means with said side member means and said piston means forming at least two units, and said conduit means leading from an area of higher pressure in one unit to an area of lower pressure in the other unit.

5. A machine according to claim 4, in which that portion in one unit of the conduit means which directly communicates with the area of higher pressure is spaced from that portion of the conduit means leading to the area of lower pressure in the other unit is spaced from the last mentioned area by less than three-fourths of the length of a piston flank in said last mentioned unit.

6. A circular piston internal combustion machine, which includes: mantle means, the inner cross-sectional surface of which has the shape of a two-arc epitrochoid with a first lobe and a second lobe located opposite to said first lobe, side member means associated with said mantle means and together therewith defining incompletely separated chamber means having gas inlet and outlet means on opposite sides of said first lobe, eccentric shaft means rotatably journaled in said side member means, rotary piston means of a spherical triangular cross-sectional shape rotatably supported by said eccentric shaft means, conduit means at least partially located in said mantle means between said inlet and said outlet means and leading into the interior of said mantle means while forming an angle with the plane passing through said first and second lobes for conveying a gas pressure from an area of higher pressure in said chamber means and leading into a gap formed by said piston means and said mantle means between said inlet and outlet means, and valve means interposed in said conduit means and adjustable to control the flow of gas therethrough.