CA1036944A - Liquid cooling system for rotary internal combustion engine - Google Patents
Liquid cooling system for rotary internal combustion engineInfo
- Publication number
- CA1036944A CA1036944A CA221,088A CA221088A CA1036944A CA 1036944 A CA1036944 A CA 1036944A CA 221088 A CA221088 A CA 221088A CA 1036944 A CA1036944 A CA 1036944A
- Authority
- CA
- Canada
- Prior art keywords
- housing
- coolant
- area
- engine
- cooling passageways
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01C—ROTARY-PISTON OR OSCILLATING-PISTON MACHINES OR ENGINES
- F01C21/00—Component parts, details or accessories not provided for in groups F01C1/00 - F01C20/00
- F01C21/06—Heating; Cooling; Heat insulation
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
Abstract
ABSTRACT
This improved liquid cooling system is for a rotary internal combustion engine having a substantially trochoidal shaped housing cavity in which a rotor planetates, the engine being so constructed and disposed that the area of highest heat flux extends vertically along one side of the engine and sub-stantially parallel to the major axis of the housing cavity.
The cooling system comprises coolant inlet means and coolant outlet means disposed in the housing respectively below and above the minor axis o the housing cavity and a plurality of parallel passages in the housing adjacent the area of highest heat flux and extending substantially parallel to the longitud-inal axis of the mainshaft, which passages are interconnected and-to-end for providing serial flow of coolant through success-ive passages from the inlet means to the outlet means so that flow of coolant is promoted by convection.
This improved liquid cooling system is for a rotary internal combustion engine having a substantially trochoidal shaped housing cavity in which a rotor planetates, the engine being so constructed and disposed that the area of highest heat flux extends vertically along one side of the engine and sub-stantially parallel to the major axis of the housing cavity.
The cooling system comprises coolant inlet means and coolant outlet means disposed in the housing respectively below and above the minor axis o the housing cavity and a plurality of parallel passages in the housing adjacent the area of highest heat flux and extending substantially parallel to the longitud-inal axis of the mainshaft, which passages are interconnected and-to-end for providing serial flow of coolant through success-ive passages from the inlet means to the outlet means so that flow of coolant is promoted by convection.
Description
103~g~4 The invention relates to liquid cooling systems for rotary internal combustion engines and, more particularly, li-quid cooling systems for the housing of the Wankel type rotary internal combustion engine.
In liquid cooling systems for the housing assembly of rotary internal combustion engines of the Wankel type, such as disclosed in the United States Patent No. 2,988,065 which issued to Felix Wankel on June 13, 1961, it is common practice to provide in the housing cooling flow passages extending sub-stantially parallel to the axis of the mainshaft and headerchambers in the housing end walls constructed and arranged to provide end-to-end interconnection of the passages and thereby provide serial flow of liquid through those passages. These conventional cooling systems are exemplified in the U. S. Patents to Lechler et al, No. 3,691,999 dated September 19, 1972, J.
Steinwart, No. 3,743,452 dated July 3, 1973, Turner et al, No.
3,289,647 dated December 6, 1966, C. Jones, No. 3,572,984 dated March 30, 1971 and M. Bentele, et al, No. 3,007,460 dated Nov-ember 7, 1961. It is well recognized that heat transfer to a liquid at a specified temperature increases with an increase in the velocity of that liquid and, therefore, it is desirable in the aforesaid cooling systems to provide a high heat transfer rate and to accomplish this high heat transfer by circulation of liquid at high velocity. Thus, cooling systems constructed to provide flow of a relatively small quantity of liquid at rela-tively high velocity in a rotary engine would require a thermo-stat and radiator of a size no larger than is required in the cooling system of a conventional reciprocating internal combus-tion of comparable size. To achieve this high velocity, the present invention contemplates a cooling system in which flow ~ ~, 10369~
is promoted by convection, which also assists in carrying out of the cooling passageways entrained bubbles of gas and water vapor.
Accordingly, it is an object of this invention to provide a cooling system for the housing of a rotary internal combustion engine which efficiently effects transfer of heat from the housing to the liquid coolant.
Another object of the present invention is to provide a cooling system for the housing of a rotary internal combustion engine wherein flow of coolant is promoted by convection.
A further object of this invention is to provide a cooling system for the housing of a rotary internal combustion engine wherein entrapment of gas and vapor is minimized.
Now, therefore, the present invention contemplates a novel cooling system in a rotary internal combustion engine of the Wankel type having a multi-lobe housing cavity wherein com-bustion occurs in the area adjacent one of the junctures of the lobes and wherein the normal operative position of the engine is such that the area of highest heat flux on the housing extends substantially vertically from a horizontal plane. ~he cooling system for the housing of such engine comprises a plurality of first cooling passageways or passes in the housing adjacent the area of highest heat flux and extending substantially parallel to the longitudinal axis of the mainshaft of the engine and with header chambers in the housing end walls arranged to provide end-to-end connection of the first cooling passageways so that coolant will serially flow through successive first cooling pass-ageways. The cooling system also calls for a coolant outlet port at the top of the housing and a coolant inlet port in the housing in the lower portion of the housing, the inlet port and outlet ~03~94~
port being in communication with ~aid first cooling passage-ways to respectively pass coolant into and from the cooling passageways. The inlet port, outlet port and header chambers coact to provide for coolant flow through the cooling passage-ways successively upwardly past the area of highest heat flux whereby movement of coolant through the passageways from the inlet port to the outlet port is promoted by convection. The cooling system may also comprise a by-pass port means in the housing through which a relatively small amount, as for example 10% of the total amount of cooling flowing through the inlet port, is diverted into second cooling passageways or passes dis-posed in the housing adjacent the area of lowest heat flux and in communication with the outlet port to discharge heated coolant into the latter.
The cooling system of this invention may also be sum-marized in the following manner.
A cooling system for the housing of a rotary internal combustion engine comprising a rotor eccentrically mounted on a mainshaft so that the rotor planetates within a multi-lobed, sub-stantially trochoidal-shaped cavity formed within the housing of the engine. The engine is disposed in its normal operative pos-ition with the major and minor axes of the cavity respectively extending substantially vertically and parallel to a horizontal plane. The combustion in the engine occurs in the area adjacent one of the lobe junctures so that the area of highest heat flux extends substantially along one side of the housing parallel to the major axis of the cavity.
The cooling system for the housing comprises a plural-ity of first cooling passageways in the housing adjacent the area where the highest heat flux is produced and extending substantially ~ -4-~03~
parallel to the longitudinal axis of the mainshaft. A header means forming chambers in the housing at opposite ends of the housing provides for connecting the first cooling passageways together end-to-end to provide for series flow of coolant through each of the plurality of first cooling passageways from one end of the housing to the other and upwardly adjacent said area of highest heat flux. An inlet means is provided in the housing at a point below the minor axis of the trochoidal cavity and adjacent the combustion exhaust gas discharge means to communicate the cooling passageways to a source of coolant to supply the first cooling passageways with coolant. The housing is also provided with an outlet means at a point above the minor axis of the tro-choidal cavity to communicate with the first cooling passageways and receive heated coolant therefrom. Second cooling passageways are in the housing adjacent the area where the lowest heat flux is produced, which passageways extend substantially parallel to the longitudinal axis of the mainshaft and in communication with the outlet means. Downstream from the inlet means a bypass means is provided to pass a portion of the coolant passing through the first cooling passageways into the second cooling passageways.
The invention will be more fully understood from the following description when considered in connection with the ac-companying drawings in which:
Fig. 1 is an exploded isometric view of the housing of a multi-rotor rotary internal combustion engine having a cooling system according to this invention, and Fig. 2 is a schematic drawing of the end view of the engine of Fig. 1 showing the relationship of the major and minor axes of the housing cavities to a horizontal plane and the heat flux (Q/A) to which the housing is subjected during engine oper-ation.
~ -4a-'~ ":.
. .
~0369~
Now referring to the drawings and more specifically to Fig. 1, the reference number 10 generally refers to the housing of a rotary internal combustion engine of the Wankel type which engine may be of the one rotor or multi-rotor type. For pur-poses of illustration only, the invention is shown in Fig. 1 as -4b-10369~4 having application to a two rotor rotary internal combustion engine. The housing 10 comprises two trochoid housing sections 12 and 14 separated by an intermediate wall section 16 and two opposite end wall sections 18 and 20. These housing components or sections 12, 14, 16, 18 and 20 are suitably aligned by dow-els (not shown) extending through aligned openings 22 and secured together into a unitary structure by tie bolts (not shown) which extend through aligned openings (not shown) in each of the hous-ing components. In the assembled condition the housing has two substantially trochoidal shaped cavities 24 within which rotors (not shown) are supported for planetation on a mainshaft (not shown), the mainshaft extending through the opening 26 in inter-mediate wall section 16 and end wall sections 18 and 20. The housing sections 12 and 14 are each provided with an exhaust port 28 and an ignition means 30, such as a spark plug. The inter-mediate housing 16 has a fuel and air supply inlet 32 which is bifurcated and communicates with two intake ports 34 and 36 in the opposite faces 37 of the intermediate housing. The intake ports 34 and 36 function to pass fuel and air into the combustion chambers (not shown) which are defined by the rotors (not shown) and disposed in cavities 24. Obviously, the invention is not limited to the intake ports 34 and 36. It is within the purview of this invention that any suitable means may be employed to provide a combustible mixture in the combustion chambers.
As best shown in Fig. 2, the engine in its normal op-erative position is orientated relative to a horizontal plane H, such that each of the major axes X--X and the minor axes Y--Y
are disposed to extend respectively substantially vertically and horizontally relative to the plane H. Also, as is shown in Fig.
; 30 2, the relative positions of intake ports 34 and 36, exhaust ports 28 and ignition means 30 are such that combustion pro-duces a heat flux Q/A of varying degree as represented by the broken line and its distance from outline of housing 10 (the greater the distance the greater the degree of heat transferred to the housing) of the engine. As herein described and as shown in Fig. 2, the area of highest heat flux extends along one side of the engine housing 10 and substantially parallel to the major axes X--X of the housing cavities 24. In order to minimize thermal distortion of housing lO as a result of the heat flux Q/A, it is necessary to provide a cooling system for the housing which compensates for this varying degree of heat flux Q/A and, therefore, in accordance with this invention, hous-ing 10 is provided with a liquid cooling system as hereinafter described.
As shown in Fig. l, the cooling system comprises an inlet port means 38 and an outlet port means 40 in end wall sec tion 18 and a first coolant passageway means in housing 10 lo-cated adjacent to the area of hiyhest heat flux to conduct a liquid coolant from inlet port means 38 to outlet port means 40 through the housing and thereby absorb heat from housing 10. The cooling system may also include a second coolant passageway means in the housing lO located adjacent the area of lowest heat flux and through which a small portion of the liquid coolant flowing through inlet port 38 is directed to flow through the second coolant passageway means.
The liquid cooling system, more specifically, provides for disposing both inlet port means 38 and outlet port means 40 in end wall section 18 of housing 10. The inlet port means 38 is located in the housing at a point below minor axes Y--Y and adjacent to or in alignment with major axes X--X. The outlet 10369~4 port means 40 is located in the housing at a point above minor axes Y--Y and adjacent to or in alignment with major axes X--X.
As shown, end wall section 18 is divided by a plurality of webs 42 into an inlet header chamber 44, an intermediate header cham-ber 46 and an outlet header chamber 48, the inlet port means 38 communicating with inlet chamber 44 to deliver liquid coolant to the latter. The end wall section 18 is also provided with passage 50 which communicates with inlet header chamber 44 to receive liquid coolant from the chamber. This passage 50 con-stitutes part of the first coolant passageway means and is inregister with a passage 52 of the adjacent housing section 12.
The passages 50 and 52 are in register with passages 54, 56 and 58 in the respective intermediate housing section 16, housing section 14 and end wall section 20. The passages 50, 52, 54, 56 and 58 coact to provide a first pass of the plurality of parallel passes or passages of the first coolant passageway means. The passage 58 communicates with a return bend chamber or intermediate header chamber 60 formed in end wall 20 by webs 62 and 64 to pass liquid coolant into the header chamber 60.
The end wall section 20 has another passage 66 which communicates with header chamber 60 to receive liquid coolant for flow back toward end wall 18. The passage 66 lies in register with pass-ages 68, 70, 72 and 74 of housing sections 14, 16, 12 and 18, respectively, which passages constitute a second pass of the ` plurality of parallel passes or passages of the first coolant passageway means. The passage 74 communicates with intermediate header chamber 46 to discharge liquid coolant into the latter.
A thlrd pass of the first coolant passageway means consists of registered passages 76, 78, 80, 82 and 84 in housing sections 30 18, 12, 16, 14 and 20, respectively, which pass communicates with intermediate header chamber 46 to receive coolant from the latter. The passage 84 in end wall section 20 communicates with a return bend chamber or intermediate header chamber 86 formed in end wall section 20. This header chamber 86 also communi-cates with a passage 88 in end wall section 20 to deliver li-quid coolant to the latter. The passage 88 registers with sim-ilar registered passages 90, 92, 94 and 96 in the respective housing sections 14, 16, 12 and 18. These registered passages 88, 90, 92, 94 and 95 constitute a fourth pass of the plurality of parallel passages of the first coolant passageway means and function to pass heated liquid coolant into outlet header cham-ber 48 in end wall section 18, which chamber communicates with passage 96. From outlet header chamber 48 the heated liquid coolant passes into outlet port means 40 which may be connected to a thermostat (not shown), radiator (not shown) and a pump (not shown) for cooling and recirculation to inlet port means 38. As is clearly evident from the foregoing description, li-quid coolant is conducted from inlet port means 38 to outlet port means 40 back and forth between end wall sections 18 and 20 through a plurality of passages which are positioned to re-ceive liquid coolant at successively higher temperaturesas the coolant absorbs heat from the housing, thereby utilizing con-vection to promote the flow of liquid coolant. Thus, the vel-ocity of flow is at a desired rate to achieve a heat transfer rate without high quantative flow of liquid coolant and a rela-tively large pump (not shown), if employed, and the attendant increase in radiator and thermostat size.
The liquid cooling system may also provide a second coolant passageway means for flowing liquid coolant in the area adjacent the portion of the housing where heat flux Q/A is least.
This low heat flux is generally located in the area of the fuel and air supply inlet 32 and exhaust ports 28 (see Fig. 2).
Since the heat transfer requirements in the area of least heat flux is low, only a small quantity of liquid coolant is nec-essary to achieve the desired heat transfer. Therefore, in accordance with the present invention, a by~pass port means 98 is provided in web 62 of end wall section 20 to communicate header chamber 60 with an adjacent header chamber 100 formed in end wall section 20 between web 62 and a web 102. The by-pass port means 98 is so sized that of the total flow of liquid cool-ant entering header chamber 60, only a small amcunt, as for ex-ample about 10~, is diverted into header chamber 100 through by-pass port means 98. From header chamber 100 the liquid cool-ant flows in a single pass to outlet header chamber 48, via registered passages 104, 106, 108, 110 and 112 in housing sec-tions 20, 14, 16, 12 and 18, respectively. The liquid coolant then flows from outlet header chamber 48 together with the li-quid coolant from the first coolant passageway means via outlet port means 40. This fluid flow through the second coolant pass-ageway means may for particular engines effect a transfer ofheat to the housing rather than from the housing in order to provide a housing having minimal thermal distortion.
It is believed now readily apparent that the present invention provides an efficient liquid cooling system for a rotary internal combustion engine in which flow velocity of the coolant through the engine housing is promoted by convection since flow thereof from the coolant inlet to the coolant outlet is in the same direction that temperature of the coolant is in-creased. It is a system in which the provision of disposing liquid coolant inlet and outlet ports in the same end wall . .
_g_ ~036944 section, eliminates in a multi-rotor engine, liquid coolant inlet and outlet manifolds and provldes simplified housing castings.
In liquid cooling systems for the housing assembly of rotary internal combustion engines of the Wankel type, such as disclosed in the United States Patent No. 2,988,065 which issued to Felix Wankel on June 13, 1961, it is common practice to provide in the housing cooling flow passages extending sub-stantially parallel to the axis of the mainshaft and headerchambers in the housing end walls constructed and arranged to provide end-to-end interconnection of the passages and thereby provide serial flow of liquid through those passages. These conventional cooling systems are exemplified in the U. S. Patents to Lechler et al, No. 3,691,999 dated September 19, 1972, J.
Steinwart, No. 3,743,452 dated July 3, 1973, Turner et al, No.
3,289,647 dated December 6, 1966, C. Jones, No. 3,572,984 dated March 30, 1971 and M. Bentele, et al, No. 3,007,460 dated Nov-ember 7, 1961. It is well recognized that heat transfer to a liquid at a specified temperature increases with an increase in the velocity of that liquid and, therefore, it is desirable in the aforesaid cooling systems to provide a high heat transfer rate and to accomplish this high heat transfer by circulation of liquid at high velocity. Thus, cooling systems constructed to provide flow of a relatively small quantity of liquid at rela-tively high velocity in a rotary engine would require a thermo-stat and radiator of a size no larger than is required in the cooling system of a conventional reciprocating internal combus-tion of comparable size. To achieve this high velocity, the present invention contemplates a cooling system in which flow ~ ~, 10369~
is promoted by convection, which also assists in carrying out of the cooling passageways entrained bubbles of gas and water vapor.
Accordingly, it is an object of this invention to provide a cooling system for the housing of a rotary internal combustion engine which efficiently effects transfer of heat from the housing to the liquid coolant.
Another object of the present invention is to provide a cooling system for the housing of a rotary internal combustion engine wherein flow of coolant is promoted by convection.
A further object of this invention is to provide a cooling system for the housing of a rotary internal combustion engine wherein entrapment of gas and vapor is minimized.
Now, therefore, the present invention contemplates a novel cooling system in a rotary internal combustion engine of the Wankel type having a multi-lobe housing cavity wherein com-bustion occurs in the area adjacent one of the junctures of the lobes and wherein the normal operative position of the engine is such that the area of highest heat flux on the housing extends substantially vertically from a horizontal plane. ~he cooling system for the housing of such engine comprises a plurality of first cooling passageways or passes in the housing adjacent the area of highest heat flux and extending substantially parallel to the longitudinal axis of the mainshaft of the engine and with header chambers in the housing end walls arranged to provide end-to-end connection of the first cooling passageways so that coolant will serially flow through successive first cooling pass-ageways. The cooling system also calls for a coolant outlet port at the top of the housing and a coolant inlet port in the housing in the lower portion of the housing, the inlet port and outlet ~03~94~
port being in communication with ~aid first cooling passage-ways to respectively pass coolant into and from the cooling passageways. The inlet port, outlet port and header chambers coact to provide for coolant flow through the cooling passage-ways successively upwardly past the area of highest heat flux whereby movement of coolant through the passageways from the inlet port to the outlet port is promoted by convection. The cooling system may also comprise a by-pass port means in the housing through which a relatively small amount, as for example 10% of the total amount of cooling flowing through the inlet port, is diverted into second cooling passageways or passes dis-posed in the housing adjacent the area of lowest heat flux and in communication with the outlet port to discharge heated coolant into the latter.
The cooling system of this invention may also be sum-marized in the following manner.
A cooling system for the housing of a rotary internal combustion engine comprising a rotor eccentrically mounted on a mainshaft so that the rotor planetates within a multi-lobed, sub-stantially trochoidal-shaped cavity formed within the housing of the engine. The engine is disposed in its normal operative pos-ition with the major and minor axes of the cavity respectively extending substantially vertically and parallel to a horizontal plane. The combustion in the engine occurs in the area adjacent one of the lobe junctures so that the area of highest heat flux extends substantially along one side of the housing parallel to the major axis of the cavity.
The cooling system for the housing comprises a plural-ity of first cooling passageways in the housing adjacent the area where the highest heat flux is produced and extending substantially ~ -4-~03~
parallel to the longitudinal axis of the mainshaft. A header means forming chambers in the housing at opposite ends of the housing provides for connecting the first cooling passageways together end-to-end to provide for series flow of coolant through each of the plurality of first cooling passageways from one end of the housing to the other and upwardly adjacent said area of highest heat flux. An inlet means is provided in the housing at a point below the minor axis of the trochoidal cavity and adjacent the combustion exhaust gas discharge means to communicate the cooling passageways to a source of coolant to supply the first cooling passageways with coolant. The housing is also provided with an outlet means at a point above the minor axis of the tro-choidal cavity to communicate with the first cooling passageways and receive heated coolant therefrom. Second cooling passageways are in the housing adjacent the area where the lowest heat flux is produced, which passageways extend substantially parallel to the longitudinal axis of the mainshaft and in communication with the outlet means. Downstream from the inlet means a bypass means is provided to pass a portion of the coolant passing through the first cooling passageways into the second cooling passageways.
The invention will be more fully understood from the following description when considered in connection with the ac-companying drawings in which:
Fig. 1 is an exploded isometric view of the housing of a multi-rotor rotary internal combustion engine having a cooling system according to this invention, and Fig. 2 is a schematic drawing of the end view of the engine of Fig. 1 showing the relationship of the major and minor axes of the housing cavities to a horizontal plane and the heat flux (Q/A) to which the housing is subjected during engine oper-ation.
~ -4a-'~ ":.
. .
~0369~
Now referring to the drawings and more specifically to Fig. 1, the reference number 10 generally refers to the housing of a rotary internal combustion engine of the Wankel type which engine may be of the one rotor or multi-rotor type. For pur-poses of illustration only, the invention is shown in Fig. 1 as -4b-10369~4 having application to a two rotor rotary internal combustion engine. The housing 10 comprises two trochoid housing sections 12 and 14 separated by an intermediate wall section 16 and two opposite end wall sections 18 and 20. These housing components or sections 12, 14, 16, 18 and 20 are suitably aligned by dow-els (not shown) extending through aligned openings 22 and secured together into a unitary structure by tie bolts (not shown) which extend through aligned openings (not shown) in each of the hous-ing components. In the assembled condition the housing has two substantially trochoidal shaped cavities 24 within which rotors (not shown) are supported for planetation on a mainshaft (not shown), the mainshaft extending through the opening 26 in inter-mediate wall section 16 and end wall sections 18 and 20. The housing sections 12 and 14 are each provided with an exhaust port 28 and an ignition means 30, such as a spark plug. The inter-mediate housing 16 has a fuel and air supply inlet 32 which is bifurcated and communicates with two intake ports 34 and 36 in the opposite faces 37 of the intermediate housing. The intake ports 34 and 36 function to pass fuel and air into the combustion chambers (not shown) which are defined by the rotors (not shown) and disposed in cavities 24. Obviously, the invention is not limited to the intake ports 34 and 36. It is within the purview of this invention that any suitable means may be employed to provide a combustible mixture in the combustion chambers.
As best shown in Fig. 2, the engine in its normal op-erative position is orientated relative to a horizontal plane H, such that each of the major axes X--X and the minor axes Y--Y
are disposed to extend respectively substantially vertically and horizontally relative to the plane H. Also, as is shown in Fig.
; 30 2, the relative positions of intake ports 34 and 36, exhaust ports 28 and ignition means 30 are such that combustion pro-duces a heat flux Q/A of varying degree as represented by the broken line and its distance from outline of housing 10 (the greater the distance the greater the degree of heat transferred to the housing) of the engine. As herein described and as shown in Fig. 2, the area of highest heat flux extends along one side of the engine housing 10 and substantially parallel to the major axes X--X of the housing cavities 24. In order to minimize thermal distortion of housing lO as a result of the heat flux Q/A, it is necessary to provide a cooling system for the housing which compensates for this varying degree of heat flux Q/A and, therefore, in accordance with this invention, hous-ing 10 is provided with a liquid cooling system as hereinafter described.
As shown in Fig. l, the cooling system comprises an inlet port means 38 and an outlet port means 40 in end wall sec tion 18 and a first coolant passageway means in housing 10 lo-cated adjacent to the area of hiyhest heat flux to conduct a liquid coolant from inlet port means 38 to outlet port means 40 through the housing and thereby absorb heat from housing 10. The cooling system may also include a second coolant passageway means in the housing lO located adjacent the area of lowest heat flux and through which a small portion of the liquid coolant flowing through inlet port 38 is directed to flow through the second coolant passageway means.
The liquid cooling system, more specifically, provides for disposing both inlet port means 38 and outlet port means 40 in end wall section 18 of housing 10. The inlet port means 38 is located in the housing at a point below minor axes Y--Y and adjacent to or in alignment with major axes X--X. The outlet 10369~4 port means 40 is located in the housing at a point above minor axes Y--Y and adjacent to or in alignment with major axes X--X.
As shown, end wall section 18 is divided by a plurality of webs 42 into an inlet header chamber 44, an intermediate header cham-ber 46 and an outlet header chamber 48, the inlet port means 38 communicating with inlet chamber 44 to deliver liquid coolant to the latter. The end wall section 18 is also provided with passage 50 which communicates with inlet header chamber 44 to receive liquid coolant from the chamber. This passage 50 con-stitutes part of the first coolant passageway means and is inregister with a passage 52 of the adjacent housing section 12.
The passages 50 and 52 are in register with passages 54, 56 and 58 in the respective intermediate housing section 16, housing section 14 and end wall section 20. The passages 50, 52, 54, 56 and 58 coact to provide a first pass of the plurality of parallel passes or passages of the first coolant passageway means. The passage 58 communicates with a return bend chamber or intermediate header chamber 60 formed in end wall 20 by webs 62 and 64 to pass liquid coolant into the header chamber 60.
The end wall section 20 has another passage 66 which communicates with header chamber 60 to receive liquid coolant for flow back toward end wall 18. The passage 66 lies in register with pass-ages 68, 70, 72 and 74 of housing sections 14, 16, 12 and 18, respectively, which passages constitute a second pass of the ` plurality of parallel passes or passages of the first coolant passageway means. The passage 74 communicates with intermediate header chamber 46 to discharge liquid coolant into the latter.
A thlrd pass of the first coolant passageway means consists of registered passages 76, 78, 80, 82 and 84 in housing sections 30 18, 12, 16, 14 and 20, respectively, which pass communicates with intermediate header chamber 46 to receive coolant from the latter. The passage 84 in end wall section 20 communicates with a return bend chamber or intermediate header chamber 86 formed in end wall section 20. This header chamber 86 also communi-cates with a passage 88 in end wall section 20 to deliver li-quid coolant to the latter. The passage 88 registers with sim-ilar registered passages 90, 92, 94 and 96 in the respective housing sections 14, 16, 12 and 18. These registered passages 88, 90, 92, 94 and 95 constitute a fourth pass of the plurality of parallel passages of the first coolant passageway means and function to pass heated liquid coolant into outlet header cham-ber 48 in end wall section 18, which chamber communicates with passage 96. From outlet header chamber 48 the heated liquid coolant passes into outlet port means 40 which may be connected to a thermostat (not shown), radiator (not shown) and a pump (not shown) for cooling and recirculation to inlet port means 38. As is clearly evident from the foregoing description, li-quid coolant is conducted from inlet port means 38 to outlet port means 40 back and forth between end wall sections 18 and 20 through a plurality of passages which are positioned to re-ceive liquid coolant at successively higher temperaturesas the coolant absorbs heat from the housing, thereby utilizing con-vection to promote the flow of liquid coolant. Thus, the vel-ocity of flow is at a desired rate to achieve a heat transfer rate without high quantative flow of liquid coolant and a rela-tively large pump (not shown), if employed, and the attendant increase in radiator and thermostat size.
The liquid cooling system may also provide a second coolant passageway means for flowing liquid coolant in the area adjacent the portion of the housing where heat flux Q/A is least.
This low heat flux is generally located in the area of the fuel and air supply inlet 32 and exhaust ports 28 (see Fig. 2).
Since the heat transfer requirements in the area of least heat flux is low, only a small quantity of liquid coolant is nec-essary to achieve the desired heat transfer. Therefore, in accordance with the present invention, a by~pass port means 98 is provided in web 62 of end wall section 20 to communicate header chamber 60 with an adjacent header chamber 100 formed in end wall section 20 between web 62 and a web 102. The by-pass port means 98 is so sized that of the total flow of liquid cool-ant entering header chamber 60, only a small amcunt, as for ex-ample about 10~, is diverted into header chamber 100 through by-pass port means 98. From header chamber 100 the liquid cool-ant flows in a single pass to outlet header chamber 48, via registered passages 104, 106, 108, 110 and 112 in housing sec-tions 20, 14, 16, 12 and 18, respectively. The liquid coolant then flows from outlet header chamber 48 together with the li-quid coolant from the first coolant passageway means via outlet port means 40. This fluid flow through the second coolant pass-ageway means may for particular engines effect a transfer ofheat to the housing rather than from the housing in order to provide a housing having minimal thermal distortion.
It is believed now readily apparent that the present invention provides an efficient liquid cooling system for a rotary internal combustion engine in which flow velocity of the coolant through the engine housing is promoted by convection since flow thereof from the coolant inlet to the coolant outlet is in the same direction that temperature of the coolant is in-creased. It is a system in which the provision of disposing liquid coolant inlet and outlet ports in the same end wall . .
_g_ ~036944 section, eliminates in a multi-rotor engine, liquid coolant inlet and outlet manifolds and provldes simplified housing castings.
Claims (4)
1. In a rotary internal combustion engine in which a rotor is eccentrically mounted on a mainshaft so that the rotor planetates within a multi-lobed, substantially trochoidal shaped cavity formed within the housing of the engine and which engine is disposed in its normal operative position with the major and minor axes of the cavity respectively extending substantially vertically and parallel to a horizontal plane and wherein combus-tion occurs in the area adjacent one of the lobe junctures so that the area of highest heat flux extends substantially along one side of the housing parallel to the major axis of said cavity, a cool-ing system for the housing of said engine comprising:
a) a plurality of first cooling passageways in the housing adjacent the area where the highest heat flux is produced and extending substantially parallel to the longitudinal axis of said main-shaft;
b) header means forming chambers in the housing at the opposite ends of said housing to con-nect said first cooling passageways together end-to-end to provide for series flow of coolant through each of said plurality of first cooling passageways from one end of the housing to the other and upwardly adjacent said area of highest heat flux;
c) inlet means in the housing at a point below the minor axis of the trochoidal cavity and adjacent the combustion exhaust gas discharge means to communicate said first cooling passageways to a source of coolant to supply the first cooling passageways with coolant, d) outlet means in the housing at a point above the minor axis to communicate with said first cooling passageways and receive heated coolant from the latter;
e) second cooling passageways in the housing adjacent the area where the lowest heat flux is produced and extending substantially par-allel to the longitudinal axis of the main-shaft and communicating with said outlet means;
and f) bypass means downstream from said inlet means for passing a portion of the coolant passing through said first cooling passageways into said second cooling passageways.
a) a plurality of first cooling passageways in the housing adjacent the area where the highest heat flux is produced and extending substantially parallel to the longitudinal axis of said main-shaft;
b) header means forming chambers in the housing at the opposite ends of said housing to con-nect said first cooling passageways together end-to-end to provide for series flow of coolant through each of said plurality of first cooling passageways from one end of the housing to the other and upwardly adjacent said area of highest heat flux;
c) inlet means in the housing at a point below the minor axis of the trochoidal cavity and adjacent the combustion exhaust gas discharge means to communicate said first cooling passageways to a source of coolant to supply the first cooling passageways with coolant, d) outlet means in the housing at a point above the minor axis to communicate with said first cooling passageways and receive heated coolant from the latter;
e) second cooling passageways in the housing adjacent the area where the lowest heat flux is produced and extending substantially par-allel to the longitudinal axis of the main-shaft and communicating with said outlet means;
and f) bypass means downstream from said inlet means for passing a portion of the coolant passing through said first cooling passageways into said second cooling passageways.
2. The cooling system of Claim 1 wherein said header means are opposite end walls, the end walls being constructed and arranged to define said header chambers.
3. The apparatus of Claim 2 wherein said bypass means is located in one of said end walls.
4. The apparatus of Claim 2 wherein said bypass means is a passageway having a flow area sized to pass only a small portion of the total quantity of coolant passing through said inlet means.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US447916A US3895889A (en) | 1974-03-04 | 1974-03-04 | Liquid cooling system for rotary internal combustion engine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1036944A true CA1036944A (en) | 1978-08-22 |
Family
ID=23778259
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA221,088A Expired CA1036944A (en) | 1974-03-04 | 1975-03-03 | Liquid cooling system for rotary internal combustion engine |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US3895889A (en) |
| CA (1) | CA1036944A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4531900A (en) * | 1984-06-07 | 1985-07-30 | John Deere Technologies International, Inc. | Rotary engine cooling system |
| US4664607A (en) * | 1985-05-30 | 1987-05-12 | Deere & Company | Rotary engine cooling system with flow balancing |
| DE3545821A1 (en) * | 1985-12-23 | 1987-07-02 | Wankel Gmbh | LIQUID-COOLED HOUSING OF A ROTARY PISTON INTERNAL COMBUSTION ENGINE |
| US4915603A (en) * | 1988-08-01 | 1990-04-10 | Brunswick Corporation | Rotary engine cooling system |
| US8033264B2 (en) * | 2008-03-09 | 2011-10-11 | Rotary Power LLC | Rotary engine |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3007460A (en) * | 1960-03-29 | 1961-11-07 | Curtiss Wright Corp | Cooling arrangement for rotary mechanisms |
| US3102516A (en) * | 1960-11-14 | 1963-09-03 | Curtiss Wright Corp | Cooling system for rotary mechanisms |
| DE1273897B (en) * | 1963-08-22 | 1968-07-25 | Nsu Motorenwerke Ag | Fluid-cooled housing for rotary piston internal combustion engines |
| GB1119861A (en) * | 1964-08-13 | 1968-07-17 | Toyo Kogyo Kabushiki Kaisha | Rotary piston internal combustion engine |
-
1974
- 1974-03-04 US US447916A patent/US3895889A/en not_active Expired - Lifetime
-
1975
- 1975-03-03 CA CA221,088A patent/CA1036944A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| US3895889A (en) | 1975-07-22 |
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