Patent Grant
11333047
This application is a national phase filing under 35 U.S.C. § 371 of International Application No. PCT/EP2018/071017 filed on Aug. 2, 2018, which claims benefit of priority from French Patent Application No. 1757398 filed Aug. 2, 2017, the contents of which are hereby incorporated by reference in their entirety.
The present invention concerns an external hot source engine.
Engines with an external hot source, for example of the Ericsson type, are experiencing renewed interest and development, with the purpose of reducing pollutant emissions or reducing energy consumption by upgrading heat emissions. This type of engine operates between two heat sources external to the engine via exchangers. It uses valves to control the flow of the working fluid (in the gas phase) between two chambers, one for compression and the other for expansion.
For volumetric machines such as in particular internal combustion piston engines, the distributions using valves actuated by cams are also known. This type of distribution has various limitations. Particularly, the pressure on the face of the valve opposite the working chamber must be low. Furthermore, the maximum valve lift is low if the duration (measured in degrees of cam rotation angle) of the valve opening is short. Furthermore, the cam drive consumes energy.
Volumetric machines are also known, such as compressors, which use a flap distribution. This solution requires that the pressure differential on each flap always has, at each stage of the machine operating cycle, an appropriate value and direction so that the flap is in the—open or closed—state necessary to the considered stage of the cycle.
In some volumetric machines with an external hot source, such as those described in the two patent applications FR 2 905 728 and FR 2 954 799, the working gas is compressed in a working chamber, then transferred in a hot source, and from there re-transferred to the same working chamber at the beginning of an expansion time of this chamber. To be effective, both aforementioned working gas transfers must be brief and take place through a passage section which is large enough to minimize the pressure drops. These requirements are difficult to meet with a distribution by flaps controlled by cams. Moreover, this type of cycle is hardly compatible with flap distribution.
The purpose of the present invention is to propose an external hot source engine to overcome at least part of the problems mentioned above. It also has the purpose of providing a space-saving engine.
According to a first aspect of the invention, at least one of the objectives is achieved with an external hot source engine comprising:
According to the invention, the distribution comprises at least one rotary slide valve mounted in rotation in the cylinder head and includes internal passages opening through the side wall thereof by at least one hole which selectively communicates with the working chamber by at least one opening made in the cylinder head.
The engine according to the invention has the advantage, compared with devices including valves, of distributing gas flows with little pressure drop, via large passage sections for very short instants. Compared to an engine implementing an ERICSSON cycle, the engine according to the invention allows significantly dividing the friction and the pressure drops. It allows improving engine efficiency while reducing the number of parts and thus the space requirement and weight of the engine.
A slide valve means a cylindrical element comprising internal passages in which the working gas can circulate. An internal passage is for example a conduit. The slide valve is disposed so that the axis of rotation thereof is perpendicular to the axis of the cylinder above which it is arranged. The slide valve is located between the working chamber and the exchanger along the working gas path. The rotary movement of the slide valve is synchronized with the reciprocating movement of the piston, so that the working gas can pass through the slide valve via the internal passages, and thus distribute the gas between the working chamber and the exchanger. Preferably, each internal passage communicates with at least two apertures formed through the side wall of the slide valve, each aperture being located at one of the two ends of the internal passage. At a certain stage of the cycle, the working gas flows between the working chamber and the cold inlet of the exchanger passing through at least one cylinder head opening and at least one internal passage of the rotating slide valve. An aperture in the slide valve which selectively coincides with at least one opening formed in the cylinder head is called hole.
The slide valve distribution system allows proposing a large section for the passage of the working gas, in particular as soon as a hole begins to coincide with a cylinder head opening. Since the speed of rotation of the slide valve is substantially constant, the passage section increases rapidly, for example linearly, until the hole coincides perfectly with the cylinder head opening. On the contrary, by its (substantially ovoid) geometry, a cam actuates a valve according to a substantially sinusoidal law so that the working gas passage section increases very slowly at the beginning of the opening movement.
The slide valve distribution allows carrying out the following four-stroke-type thermodynamic cycle:
Thanks to the slide valve, both aforementioned transfers of the working gas are brief and take place through a passage section large enough to minimize the pressure drops.
Preferably, at least one opening of the cylinder head is capable of communicating with two internal passages of the slide valve which open through the side wall of the slide valve by two circumferentially aligned holes. The angular deviation between the two neighboring holes is comprised between 5 and 15 degrees. These values, like the angular values given below, concerning the holes and the orifices, are indicated for a speed of rotation of the slide valve comprised between 3000 and 4000 rpm (revolutions per minute) and a temperature of the heat yielding fluid comprised between 500° C. and 600° C. (degrees Celsius). Said two internal passages are, one, is a passage through which the working gas enters in the working chamber, and the other, is a passage through which the working gas leaves the working chamber. This characteristic allows a working gas leaving the working chamber, and a working gas entering the working chamber, to intersect each other. Thus an unfavorable phenomenon of relatively low pressure in the working chamber at the beginning of the expansion phase is avoided.
For example, the slide valve comprises:
The working gas entering the exchanger is called “cold” working gas by comparison with the higher temperature thereof when it leaves “hot” from the exchanger. It should however be understood that the “cold” working gas entering the exchanger is already reheated by its compression in the working chamber. Likewise, the “cold” end of the exchanger is still at a temperature close to that of the working gas at the end of compression.
Preferably, the distribution is arranged so that, at the end of the compression, the working chamber begins to communicate with the cold end of the exchanger when the pressure in the working chamber is lower than the pressure in the exchanger. During operation of the engine and with reference to the cycle described above, the working gas which is cold and compressed and/or being compressed enters in the rotating slide valve as soon as at least a portion of the hole coincides with the opening so as to circulate the cold and compressed working gas to the cold end of the exchanger. The passage section between the working chamber and the hole increases with the rotation of the slide valve. When the hole of the slide valve coincides perfectly with the cylinder head opening, the passage section is maximum. The major portion, at least 50%, of the volume of the cold and compressed working gas then has passed through said hole. Then, due to the rotation of the slide valve and the end of compression, only a portion of the hole coincides with the opening, so as to circulate the remaining portion of the cold and compressed working gas to the cold end of the exchanger. Simultaneously, the passage section between the working chamber and the second hole, of the second internal passage, increases so that a portion of said hole coincides with the same opening. The working gas leaving the second hole, and therefore entering the working chamber, comes from the hot end of the exchanger after being heated. The working gas thus makes a loop passing through the same cylinder head opening but through different internal passages of the slide valve. This allows making said larger opening, and therefore further increasing the passage section provided to the gas to pass into and return from the exchanger. For a short time, the cold working gas and the hot working gas intersect each other.
In one embodiment, at the end opposite the holes, the internal passages open through the side wall of the slide valve by orifices which selectively communicate with fixed connectors according to the angular position of the slide valve. The orifices of the slide valve allow the working gas to flow from the internal passages of the slide valve to the connectors or from the connectors to the internal passages of the slide valve.
Preferably, for each internal passage, the geometry of the at least one slide valve is such that the orifice is capable of communicating with the corresponding connector when the hole communicates with the working chamber. This characteristic allows communicating the working chamber with the connectors, so as to circulate the working gas.
Said connectors comprise a cold connector communicating with the cold end of the exchanger and a hot connector communicating with the hot end of the exchanger. Said connectors comprise an intake connector communicating with the working gas intake and an exhaust connector communicating with the working gas exhaust.
For the above and for the rest of the request, the terms hole and orifice correspond to or qualify apertures made through the side wall of the slide valve. The term hole is used to qualify each aperture capable of communicating with the cylinder head opening for the passage of the working gas from the working chamber to the slide valve or vice versa. The term orifice is used to qualify each aperture capable of communicating with a connector for the passage of the working gas from the slide valve to the connector or vice versa. A hole cannot be used as an orifice and vice versa. For this purpose, on the side wall of the at least one slide valve, the at least one hole is axially offset relative to the at least one orifice.
According to one embodiment, the holes and orifices or apertures of the slide valve are only arranged through the side wall.
According to another embodiment, the holes and orifices or apertures of the slide valve can be, partly or only, arranged through the two axial faces of the slide valve.
According to a preferred embodiment, the engine comprises a low-pressure slide valve controlling the selective communication of the working chamber with the intake and the exhaust. The engine comprises a high-pressure slide valve controlling the selective communication of the working chamber with the hot and cold ends of the exchanger. This characteristic allows simplifying the construction of the engine by separating the flows called “high pressure” flows from the flows called “low pressure” flows and reducing the space requirement thereof. The slide valves can have identical or different diameters. Slide valves of identical diameter allow simplifying the construction of the engine. This embodiment also meets the concern of providing a relatively large section for the passage of gas going to and returning from the exchanger, since the gas then being compressed, the volume which must flow is smaller than at the intake and at the exhaust. However, a high-pressure slide valve with a larger diameter than the diameter of the low-pressure slide valve allows further enlarging the passage section of the internal passages, going to and returning from the exchanger.
Preferably, the engine comprises two fixed connectors, a connector called “high pressure” connector and a connector called “low pressure” connector. The high-pressure connector comprises a cold connector communicating with the cold end of the exchanger and a hot connector communicating with the hot end of the exchanger. The low-pressure connector comprises an intake connector and an exhaust connector.
According to a preferred embodiment, the thermodynamic cycle is carried out in a single cylinder. The cylinder head, surmounting the working chamber, supports the high-pressure slide valve and the low-pressure slide valve, which are disposed parallel to each other viewed parallel to the axis of the slide valve. The cylinder head has a general geometric shape evoking a triangle. It has a lower face and two curvilinear lateral faces whose upper ends meet.
The cylinder head has two concave and opposite lateral faces, each face being arranged to receive a cylindrical slide valve, by shape complementarity. Particularly, each lateral face has a circular-arc-shaped section substantially coaxial with the axis of the received slide valve. The openings are made in the lateral faces. Preferably, the openings are rectangular in shape to limit the pressure drops.
The cylinder head has a substantially planar lower face intended to be in contact with the engine liner. The lower face comprises a chamber aperture which defines the entrance to a transition cavity and which, during engine operation, extends the volume of the working chamber (similar in shape to the shape of the cylinder) viewed parallel to the axis of the slide valves. The transition cavity has a substantially triangular shape. Preferably, the piston head has a complementary shape to the shape of the transition cavity, so that the head can enter the transition cavity.
According to one embodiment, the at least one hole comprises two holes for a same internal passage, capable of simultaneously communicating with the working chamber, by two openings. Each hole can coincide with one opening. This characteristic is particularly advantageous in order to find a compromise between a large section for the passage of the working gas flow, limiting the pressure drop of said flow and limiting the working gas leaks between the slide valve and the cylinder head. This compromise is all the more important for the high-pressure slide valve.
For example, during the phase of compressing the working gas and during the conveying thereof to the cold end of the exchanger, the gas passes through the two holes of the high-pressure slide valve passing through the two openings of the cylinder head so that the flow is divided in two to pass through the two openings and the two holes, forming two flow lines. After the two holes, each flow line circulates in a conduit opening into a common conduit. The internal passage in fact has a Y-shape according to this particular embodiment.
Preferably, the openings and the holes have a rectangular shape to limit pressure drops.
In a preferable manner, at least one of the holes is subdivided by at least one mullion. This characteristic allows maintaining sealing devices, placed on the cylinder head, when the at least one hole passes in front of a cylinder head opening. The mullions can equip both the holes of the low-pressure slide valve and those of the high-pressure slide valve.
For the above and for the rest of the description, mullion means a bar provided to subdivide only the hole without protruding inside the slide valve (without subdividing the internal passage). It extends circumferentially to connect two longitudinal sides of a hole so as to extend the circumference of the slide valve.
According to another embodiment, which may be compatible with the previous embodiment, at least one passage comprises two passages leading in parallel to a same resource, capable of simultaneously communicating each with one respective opening of the cylinder head. This characteristic allows proposing a large working gas passage section.
For example, when the working gas coming from the hot end of the exchanger has returned, the working gas flow is divided into two flow lines, which circulate in two separate internal passages inside the slide valve. The two flow lines are divided before entering the two orifices of the slide valve and meet after leaving the two openings of the cylinder head.
Preferably, the shape of the sections and the route of the internal passages are made to promote the circulation of the working gas in specific directions, for example to promote the gas suction, in particular to avoid a compression effect in the slide valve. Furthermore, they are arranged to limit the differential pressures along each slide valve. This allows limiting the friction between the slide valve and the cylinder head and thus limit the risks of leakage of the working gas around the slide valve.
According to other embodiments, the external hot source engine can comprise several cylinders such as an internal combustion engine. For example, the engine may comprise at least two cylinders. In this case, it can comprise all or part of the characteristics described so far. The at least one slide valve may include two orifices aligned circumferentially to selectively communicate with a same connector, and which communicate each with a respective passage associated with a respective one of the cylinders. This characteristic allows reducing the space requirement of the slide valve and therefore the space requirement of the engine.
The orifices are for example 180 degree opposite one another and the internal passages upstream of said orifices are adjoining and have a common wall.
In the case of two or more cylinders, the slide valve is advantageously the same for all the cylinders which are disposed in line with each other.
Preferably, the engine comprises sealing devices for limiting gas leakage. The openings are surrounded by sealing devices to close the gap between the peripheral wall of the slide valve and an adjacent surface of the cylinder head all around each opening. The sealing device may comprise bars made of a material for dry friction, for example graphite. For example, the bars are disposed on the lateral faces of the cylinder head around the openings.
According to another aspect of the invention, which may be compatible with the first aspect, an engine drive assembly is provided comprising an engine according to one or more of the characteristics set out above and a heat exchanger having a heat receiving path extending between a cold end and a hot end selectively connected to the working chamber at the end of a compression phase and at the beginning of an expansion phase, respectively. The working gas circulates in the heat receiving path.
Preferably, the exchanger is of the countercurrent type. The heat exchanger comprises a heat yielding path traveled in one direction by a heat yielding fluid, a direction which is opposite to the direction of travel of the working gas in the heat receiving path. The heat yielding path is distinct from the heat receiving path.
According to one embodiment, the heat exchanger comprises a heat yielding path traveled by the exhaust gases of an internal combustion engine. According to another embodiment, the heat exchanger comprises a heat yielding path traveled by a fluid reheated with solar energy.
Other advantages and features of the invention will become apparent upon reading the detailed description of non-limiting implementations and embodiments, and of the following appended drawings:
As these embodiments are in no way limiting, it will in particular be possible to consider variants of the invention comprising only a selection of characteristics described below isolated from the other described characteristics (even if this selection is isolated within a sentence comprising these other characteristics), if this selection of characteristics is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art. This selection comprises at least one characteristic, preferably functional, without structural details, and/or with only part of the structural details if this part only is enough to confer a technical advantage or to differentiate the invention from the state of the art.
The engine is connected to a heat exchanger 6 for a heat exchange between the working gas, said heat receiving fluid, and a heat yielding fluid. The heat exchanger 6 is of the countercurrent type. It comprises a heat yielding path 61 traveled by the heat yielding fluid from left to right. It further comprises a heat receiving path 62, shown under the heat yielding path 61, with reference to
The heat exchanger 6 is connected to the engine by means of connectors and pipes so as to be able to circulate the working gas from the engine to the exchanger and vice versa. Likewise, one or more connector(s) or pipe(s) are connected to the engine to make the intake and exhaust.
The distribution comprises two rotary slide valves 20, 30 mounted in rotation in the cylinder head 4, above the working chamber 5. The axes of rotation of the two slide valves are parallel to each other and orthogonal to the axis of the cylinder 2. The slide valves comprise a slide valve called “low pressure” slide valve 30 arranged and configured to control the selective communication of the working chamber 5 with the intake A and the exhaust D. The slide valves comprise a slide valve called “high pressure” slide valve 20 arranged and configured to control the selective communication of the working chamber 5 with the hot C and cold B ends of the exchanger 6. Preferably, the high-pressure slide valve is used only to control the working gas circulation between the working chamber and the exchanger. Likewise, the low-pressure slide valve is used only to control the intake and exhaust. This characteristic allows simplifying the construction of the engine by separating the flows called “high pressure” flows from the flows called “low pressure” flows and reducing the space requirement thereof. The slide valves have identical diameters allowing to simplify the construction of the engine.
Each slide valve 20, 30 comprises internal passages for conducting the working gas between the working chamber 5 and the resources. Each internal passage has two ends which open through the side wall of a slide valve each by at least one aperture. The distribution is arranged and configured so that the rotary movements of the slide valves are synchronized with the reciprocating movement of the piston, so that the working gas can pass through the slide valves via the internal passages. The apertures are arranged and configured to selectively coincide with at least one opening made in the cylinder head and at least one opening made in a fixed connector. The aperture facing the cylinder head opening when the working gas passes between the working chamber and the slide valve or vice versa is called the hole. The aperture facing a connector when the working gas passes between the slide valve and said connector or vice versa is called the orifice. A hole cannot be used as an orifice and vice versa. For this purpose, the orifices have an axial offset with the holes.
According to one embodiment of an engine comprising a single cylinder, the low-pressure slide valve comprises:
the high-pressure slide valve comprises:
The slide valve distribution allows carrying out the thermodynamic cycle the main phases of which will now be described.
With reference to
Then the piston rises so that the trapped working gas is compressed in the working chamber. With reference to
With reference to
A communication between the cold end B and the hot end C of the exchanger is then established so that a portion of the incoming working gas and a portion of the outgoing working gas comes into contact. Working gas still passes through the internal passage between the cold hole and the cold orifice, and working gas passes through the internal passage between the hot orifice and the hot hole. The volume of gas previously compressed is in fact distributed in the path between the cold end B and the hot end C of the exchanger 6, the working gas being heated thanks to the heat yielding fluid present in the heat yielding path 61 of the exchanger 6. Simultaneously, no hole of the low-pressure slide valve communicates with a cylinder head opening.
Afterwards, the heated working gas leaving the high-pressure slide valve expands in the working chamber. With reference to
With reference to
Preferably, the exhaust connector and the intake connector form a single part comprising at least one inlet for the intake and at least one outlet for the exhaust, each of the resources being transferred into a respective conduit. For the rest, an exhaust connector and/or an intake connector can indifferently be referred to a connector called “low pressure” connector.
Thanks to the slide valve, the transfers of the working gas are brief and take place through a passage section large enough to minimize the pressure drops. Furthermore, since the thermodynamic cycle can be carried out in a single cylinder, the engine has a very small space requirement compared to the external hot source engine of the prior art.
A specific embodiment will now be described, which will be described in these differences with the above embodiment. According to one embodiment, an external hot source engine comprising two cylinders is provided.
With reference to
The cylinder head 4 is then provided to surmount an engine block in which two cylinders are formed. It has a lower face 46 and two lateral faces (not visible in
The lower face 46 is substantially planar and is intended to be in contact with the engine liner. It comprises two chamber apertures 46a, 46b, each chamber aperture being provided to coincide with a cylinder of the engine. Each chamber aperture 46a, 46b defines an entrance to a transition cavity 45 hollowed inside the cylinder head. The transition cavity 45 has a substantially triangular shape and is, in operation, opposite the working chamber. Preferably, the piston head has a complementary shape to the shape of the transition cavity, so that the head can enter the transition cavity. When the engine is in operation, the volume of the cavity extends the volume of the working chamber.
According to the embodiment represented by
For one cylinder, two openings called “high-pressure” openings 41hp are provided for circulating the gas to the high-pressure slide valve and vice versa, and two openings called “low-pressure” openings 41bp are provided for circulating the working gas to the low-pressure slide valve and vice versa. The high-pressure openings 41hp are made on a same first lateral face of the cylinder head. The low-pressure openings 41bp are made on a same lateral face of the cylinder head opposite the first face; the four openings opening into a transition cavity.
With reference to
The receiving surface 40 has a concave shape, so as to cooperate by shape complementarity with the high-pressure slide valve 20. Particularly, the receiving surface has a circular-arc-shaped section substantially coaxial with the axis of the received slide valve. The arrangement of the cylinder head 4 is substantially symmetrical as regards the shape of the lateral faces. The high-pressure slide valve like the low-pressure slide valve has, according to a cross section, a circular external shape. Furthermore, the two slide valves have a substantially identical diameter.
According to the embodiment shown in
In this particular position, no working gas circulates in internal passages of the high-pressure slide valve 20.
With reference to
Furthermore, the openings 41 are spaced from each other so that the orifices (cold and hot) are opposite the receiving surface 40 of the cylinder head 4 between two openings. Preferably, the spacing between two transverse edges of two adjacent openings is equal to or greater than the transverse dimension of an orifice. The orifices are therefore dimensioned depending on the spacing between two openings, or on the spacing between one opening and the axial end of the receiving surface. Thus, for example, the cold orifice 23a is circumferentially aligned with the circumferential surface separating the two cold holes 21a.
With reference to
For example, each hot hole has, along the circumference of the slide valve, an angular aperture comprised between 20 and 50 degrees, preferably between 25 and 35 degrees. Given that the engine carries out four main phases and that the internal passages are separated by walls of non-zero thickness, these values are selected according to a compromise between the need for a large section for the passage of the working gas flow, the reduction of pressure drops and the space requirement (diameter and length of the slide valve). Each cold hole has, along the circumference of the slide valve, an angular aperture comprised, for example, between 10 and 40 degrees, preferably between 20 and 30 degrees.
Furthermore, each opening 41hp has, along the circumference of the receiving surface 40, an angular aperture comprised, for example, between 15 and 30 degrees.
Preferably, the orifices have, along the circumference of the slide valve, an angular aperture comprised between 100 and 350 degrees, preferably between 120 and 150 degrees.
Concerning the cylinder b and according to the particular angular position of the high-pressure slide valve, the synchronization of the engine is such that no hole communicates with the openings 41b of the cylinder head. With reference to
Between the portion of the high-pressure slide valve selectively communicating with the cylinder a and the portion of the high-pressure slide valve selectively communicating with the cylinder b, the holes and orifices are respectively diametrically opposite.
The angular positions of the high-pressure slide valve 20 when the working gas circulates between the working chamber of the cylinder b and the exchanger will now be described with reference to
Referring to
Furthermore, one can also partially distinguish two hot orifices 24a intended to communicate respectively with two openings of the high-pressure connector 60 so that the working gas coming from the hot end of the exchanger can circulate from the high-pressure connector (via two openings, an opening 64a and an opening 65) to the high-pressure slide valve 20 towards the working chamber of the cylinder a.
With reference to
With reference to
The synchronization of the engine is such that the hot orifices 24b communicate with openings (the opening 65 and a second opening which is not visible) of the high-pressure connector 60 so that the working gas circulates from the hot end of the exchanger to the high-pressure slide valve 20, and simultaneously the hot holes 22b, in accordance with the hot holes of
During operation of the engine and with reference to the cycle described above, the working gas which is cold and compressed and/or being compressed enters the rotating high-pressure slide valve 20 as soon as at least a portion of the two cold holes 21b communicates with the openings 41b so as to circulate the cold and compressed working gas to the cold end of the exchanger. The passage section between the working chamber and the cold holes increases with the rotation of the high-pressure slide valve. When the cold holes of the high-pressure slide valve coincide perfectly with the cylinder head openings, the passage section is maximum. The major portion of the cold and compressed working gas volume has passed through said holes. Then, due to the rotation of the high-pressure slide valve and to the end of compression, only a portion of the holes communicates with the openings, so as to circulate the remaining portion of the cold and compressed working gas to the cold end of the exchanger. Simultaneously, the passage section between the working chamber and the hot holes increases so that a portion of said hot holes communicates with the same opening. The working gas leaving the hot holes, and therefore entering the working chamber, comes from the hot end of the exchanger after being heated. The working gas thus makes a loop passing through the same openings of the cylinder head but through different internal passages of the high-pressure slide valve. For a short time the cold working gas and the hot working gas intersect each other.
According to a particular embodiment of the high-pressure slide valve provided for an engine comprising two cylinders, the high-pressure slide valve 20 includes two orifices circumferentially aligned to selectively communicate with the high-pressure connector. With reference to
The angular positions of the low-pressure slide valve 30 when the working gas circulates between the working chamber of one of the cylinders and a low-pressure connector 70 will now be described with reference to
A high engine similar to
for the cylinder a, working gas is taken into the working chamber (intake phase), and
for the cylinder b, the working gas undergoes an expansion phase.
In this particular position, no working gas circulates in internal passages of the high-pressure slide valve.
With reference to
During operation, the outside air, serving as working gas, is introduced into the low-pressure connector via an intake inlet 71. The intake orifice 34a has a rectangular shape the longitudinal dimension of which extends in a direction which is orthogonal to axis of rotation of the slide valve.
With reference to
Furthermore, with reference to
With reference to
Preferably, each exhaust hole has, along the circumference of the low-pressure slide valve, an angular aperture comprised between 70 and 100 degrees, preferably between 80 and 90 degrees. Furthermore, each intake hole has, along the circumference of the slide valve, an angular aperture comprised, for example, between 70 and 100 degrees, preferably between 80 and 90 degrees.
Furthermore, each opening 41bp has, along the circumference of the receiving surface 40, an angular aperture comprised, for example, between 40 and 100 degrees.
Preferably, the intake and exhaust orifices have, along the circumference of the slide valve, an angular aperture comprised between 30 and 60 degrees, preferably between 40 and 55 degrees.
Between the portion of the low-pressure slide valve selectively communicating with the cylinder a and the portion of the low-pressure slide valve selectively communicating with the cylinder b, the holes and orifices are respectively diametrically opposite according to the shown embodiment.
Concerning the cylinder b and according to the particular angular position of the low-pressure slide valve, the synchronization of the engine is such that no hole coincides with the openings 41b of the cylinder head. With reference to
With reference to
Furthermore, each pair of openings 41bp is spaced from one another along the receiving surface 40 so that the exhaust orifices are opposite the receiving surface 40 of the cylinder head 4 separating the opening 41a pair from the opening 41b pair. Preferably, the spacing between the two opening pairs is equal to or greater than the transverse dimension of an exhaust orifice.
| Number | Date | Country | Kind |
|---|---|---|---|
| 1757398 | Aug 2017 | FR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2018/071017 | 8/2/2018 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2019/025555 | 2/7/2019 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 4008574 | Rein | Feb 1977 | A |
| 4133172 | Cataldo | Jan 1979 | A |
| 20060213207 | Redlich | Sep 2006 | A1 |
| 20080148731 | Cao | Jun 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 2816013 | Dec 2014 | EP |
| 2905728 | Mar 2008 | FR |
| 2954799 | Jul 2011 | FR |
| Number | Date | Country | |
|---|---|---|---|
| 20200240297 A1 | Jul 2020 | US |
