GB2576912A - A rotary valve internal combustion engine - Google Patents
A rotary valve internal combustion engine Download PDFInfo
- Publication number
- GB2576912A GB2576912A GB1814524.3A GB201814524A GB2576912A GB 2576912 A GB2576912 A GB 2576912A GB 201814524 A GB201814524 A GB 201814524A GB 2576912 A GB2576912 A GB 2576912A
- Authority
- GB
- United Kingdom
- Prior art keywords
- rotary valve
- valve
- crankcase
- combustion
- inlet
- 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.)
- Withdrawn
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L7/00—Rotary or oscillatory slide valve-gear or valve arrangements
- F01L7/02—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves
- F01L7/021—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves with one rotary valve
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L7/00—Rotary or oscillatory slide valve-gear or valve arrangements
- F01L7/02—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves
- F01L7/021—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves with one rotary valve
- F01L7/023—Cylindrical valves having a hollow or partly hollow body allowing axial inlet or exhaust fluid circulation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L7/00—Rotary or oscillatory slide valve-gear or valve arrangements
- F01L7/02—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves
- F01L7/028—Rotary or oscillatory slide valve-gear or valve arrangements with cylindrical, sleeve, or part-annularly shaped valves having the rotational axis coaxial with the cylinder axis and the valve surface not surrounding piston or cylinder
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- F01M13/00—Crankcase ventilating or breathing
- F01M13/02—Crankcase ventilating or breathing by means of additional source of positive or negative pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L2250/00—Camshaft drives characterised by their transmission means
- F01L2250/06—Camshaft drives characterised by their transmission means the camshaft being driven by gear wheels
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- F01M13/00—Crankcase ventilating or breathing
- F01M2013/0038—Layout of crankcase breathing systems
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Lubrication Details And Ventilation Of Internal Combustion Engines (AREA)
- Lubrication Of Internal Combustion Engines (AREA)
- Cylinder Crankcases Of Internal Combustion Engines (AREA)
Abstract
A rotary valve internal combustion engine operating on the four-stroke cycle comprising: a piston connected to a crankshaft (3, fig.1) located in a crankcase and reciprocatable in a cylinder, a valve housing defining a bore and a rotary valve (5, fig.1) rotatable in the bore in the valve housing. The rotary valve has a hollow valve body having an interior volume forming a part of the combustion chamber, wherein the interior volume of the hollow valve body is subjected to combustion gases throughout the combustion process. An inlet port being located in an inlet tract downstream of carburettor 26, wherein a fluid passage pipe is provided between the inlet tract and the crankcase. The fluid connection between the crankcase and the inlet tract allows blow-by gases in the crankcase caused by leakage past the piston during combustion, to be vented into the inlet tract and hence to the inlet port.
Description
(54) Title of the Invention: A rotary valve internal combustion engine Abstract Title: A rotary valve internal combustion engine with a crankcase to inlet tract fluid connection (57) A rotary valve internal combustion engine operating on the four-stroke cycle comprising: a piston connected to a crankshaft (3, fig.1) located in a crankcase and reciprocatable in a cylinder, a valve housing defining a bore and a rotary valve (5, fig. 1) rotatable in the bore in the valve housing. The rotary valve has a hollow valve body having an interior volume forming a part of the combustion chamber, wherein the interior volume of the hollow valve body is subjected to combustion gases throughout the combustion process. An inlet port being located in an inlet tract downstream of carburettor 26, wherein a fluid passage pipe is provided between the inlet tract and the crankcase. The fluid connection between the crankcase and the inlet tract allows blow-by gases in the crankcase caused by leakage past the piston during combustion, to be vented into the inlet tract and hence to the inlet port.
12 19
A rotary valve internal combustion engine
The present invention relates to a rotary valve internal combustion engine, particularly but not exclusively, for a manually held machine such as a horticultural strimmer or hedge trimmer, in which the control of the intake and exhaust gases of combustion is achieved by means of a rotary valve.
According to the present invention there is provided a rotary valve internal combustion engine operating on the four stroke cycle comprising: a piston connected to a crankshaft located in a crankcase and reciprocatable in a cylinder, the cylinder having a combustion end, a combustion chamber being defined in part by the piston and the combustion end of the cylinder, a valve housing fixed at an outer portion of the combustion end of the cylinder and defining a bore and a rotary valve rotatable about a rotary valve axis in the bore in the valve housing, the rotary valve having a hollow valve body having an interior volume forming a part of the combustion chamber, wherein the interior volume of the hollow valve body is subjected to combustion gases throughout the combustion process, and further having in a wall part thereof a port giving, during rotation of the valve, fluid communication successively to and from the combustion chamber via inlet and exhaust ports in the valve housing wherein a fluid passage is provided between the inlet port and the crankcase.
A preferred embodiment of the present invention will now be described by way of example with reference to the accompanying drawings, in which:Figure 1 shows a cross-sectional view of a single cylinder air cooled spark ignition rotary valve internal combustion engine, and
Figure 2 shows a perspective view of the underside of the engine of Figure 1.
Referring now to Figure 1, there is shown a single cylinder air cooled engine. The engine has a cylinder housing containing the cylinder 2. A piston 1 is connected in the conventional manner to a crankshaft 3 mounted for rotation in a crankcase 14 for reciprocation in the cylinder 2. The upper part of the cylinder 2 is closed by a combustion chamber 4 in a combustion chamber housing. The combustion chamber housing has an inlet port 27 for the flow of inlet air/fuel mix into the combustion chamber and an exhaust port 28 for venting the exhaust gas into and out of the combustion chamber 4, the gas flows being controlled by a rotary valve 5. In this embodiment, the valve 5 is rotatable in a valve housing 8 in the combustion chamber housing about an axis 5a which is co-axial with the axis of the cylinder
2. In other embodiments, the axis of rotation of the valve body is offset from the axis 5a of the cylinder 2.
At its end remote from the combustion chamber 4, the rotary valve 5 has a concentric drive shaft 6 carrying a single race ball bearing 7 which rotatably supports the valve 5 in the valve housing 8. The valve driveshaft 6 is secured to a coaxial driven gear 9 which meshes with a drive gear 10 of a drive arrangement 11 through which the driven gear 9 and hence the rotary valve 5 is connected to the crankshaft 3. The drive arrangement 11 includes a drive shaft 12 which is located in a channel or tube 17 in the cylinder housing and mounted for rotation in an upper bearing 18 adjacent the drive gear 10 and a lower bearing 13 adjacent the crankshaft
3. The driveshaft 11 carries a bevel gear 15 which meshes with a corresponding bevel gear 16 secured on the crankshaft for rotation with the crankshaft 3. Thus, the rotation of the crankshaft 3 and hence the piston movement is coordinated with the rotation of the rotary valve 5 so that the engine operates on the conventional four stroke cycle. To achieve this, the diameter of the driven gear 9 is twice that of the drive gear 10 so that the rotary valve 5 rotates at half engine speed. The rotary valve 5 comprises a generally cylindrical rotary valve body 5 rotatable about a rotary valve axis 5a with a close sliding fit in the bore in the valve housing 8, the rotary valve 5 having a hollow valve body having an interior volume 19 forming a part of the combustion chamber. The valve has a generally cylindrical body part comprising the valve body 19 itself which is slightly larger in diameter than the shaft 6, which forms a shoulder 14 against which the inner race of the ball bearing 7 is located. The valve body 19 extends into the combustion chamber and has in its interior a volume 20 which forms part of the combustion chamber 4 and which is subject to combustion gases at all stages of the combustion process.
The shaft 6 part of the rotary valve 5 is only slightly smaller in diameter than the valve body 19 to provide the shoulder 14. The shaft is solid to provide a good path for conducting heat from the valve body 19 to the exterior.
The rotary valve body 19 has a port 21 which, during rotation of the valve, enables fluid communication successively to and from the interior volume of the valve and hence the combustion chamber via the inlet and exhaust ports in the valve housing. In this embodiment the port 21 is in the form of a recess formed in the lower peripheral edge 22 of the wall 23 of the valve body adjacent to the combustion chamber 4 the recess extending upwardly from this lower edge of the wall of the valve to form the port 21 in the side of the valve.
Ignition is provided by a spark plug secured into a plug bore 25 formed in the valve housing 8 and extending into the valve bore. In an alternative embodiment, the engine operates on the compression ignition principle.
Referring now to Figure 2 there is shown a perspective underside view of the engine according to Figure 1 showing the crankcase 3 and a carburettor 26 connected to an inlet tract 52 downstream of the carburettor 26 and hence to a fluid connection to the inlet port 27 of the engine. A fluid connection between inlet tract 52 and the crankcase 3 is formed by a pipe 51 which is connected to the crankcase 3 by a connection 53 adjacent to the bevel gears 15, 16 of the drive arrangement 11.
The fluid connection between the crankcase and the inlet tract allows blow-by gases in the crankcase generated by leakage of combustion gases past the piston during combustion, to be vented into the inlet tract and hence to the inlet port 27. In operation, during each upward stroke of the piston a negative pressure is generated in the crankcase caused by the increase in crankcase volume and this will draw a small amount of inlet gas from the inlet tract into the crankcase. This inlet gas will mix with the crankcase gases. During each downward stroke of the piston which reduces the crankcase volume, a small amount of the crankcase gas will be expelled into the inlet tract. This will allow an equilibrium between inlet mixture and crankcase mixture to build up in the crankcase ensuring the lubrication of the crankcase.
Claims (3)
1. A rotary valve internal combustion engine operating on the four stroke cycle comprising: a piston connected to a crankshaft located in a crankcase and reciprocatable in a cylinder, the cylinder having a combustion end, a combustion chamber being defined in part by the piston and the combustion end of the cylinder, a valve housing fixed at an outer portion of the combustion end of the cylinder and defining a bore and a rotary valve rotatable about a rotary valve axis in the bore in the valve housing, the rotary valve having a hollow valve body having an interior volume forming a part of the combustion chamber, wherein the interior volume of the hollow valve body is subjected to combustion gases throughout the combustion process, and further having in a wall part thereof a port giving, during rotation of the valve, fluid communication successively to and from the combustion chamber via inlet and exhaust ports in the valve housing, the inlet port being located in an inlet tract, wherein a fluid passage is provided between the inlet tract and the crankcase.
2. A rotary valve internal combustion engine according to claim 1, wherein a carburettor is connected to the inlet tract to provide a fuel air mix to the inlet tract, the fluid passage being connected to the inlet tract downstream of the carburettor.
3. A rotary valve internal combustion engine according to claim 1 or 2 wherein the fluid passage comprises a pipe.
Intellectual
Property
Office
Application No: GB1814524.3
Examiner: Mr Gareth Bond
Priority Applications (8)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1814524.3A GB2576912A (en) | 2018-09-06 | 2018-09-06 | A rotary valve internal combustion engine |
| TW108101974A TW202010928A (en) | 2018-09-06 | 2019-01-18 | A rotary valve internal combustion engine |
| JP2021509788A JP7440493B2 (en) | 2018-09-06 | 2019-09-04 | rotary valve internal combustion engine |
| PCT/EP2019/073575 WO2020049040A1 (en) | 2018-09-06 | 2019-09-04 | A rotary valve internal combustion engine |
| GB1912678.8A GB2577397B (en) | 2018-09-06 | 2019-09-04 | A rotary valve internal combustion engine |
| US17/272,867 US11377982B2 (en) | 2018-09-06 | 2019-09-04 | Rotary valve internal combustion engine |
| EP19765443.7A EP3847346A1 (en) | 2018-09-06 | 2019-09-04 | A rotary valve internal combustion engine |
| CN201980058700.7A CN112673153B (en) | 2018-09-06 | 2019-09-04 | rotary valve internal combustion engine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1814524.3A GB2576912A (en) | 2018-09-06 | 2018-09-06 | A rotary valve internal combustion engine |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB201814524D0 GB201814524D0 (en) | 2018-10-24 |
| GB2576912A true GB2576912A (en) | 2020-03-11 |
Family
ID=63921180
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1814524.3A Withdrawn GB2576912A (en) | 2018-09-06 | 2018-09-06 | A rotary valve internal combustion engine |
Country Status (2)
| Country | Link |
|---|---|
| GB (1) | GB2576912A (en) |
| TW (1) | TW202010928A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1530034A (en) * | 1975-03-25 | 1978-10-25 | Nissan Motor | Combination of a crankcase ventilation system and a charge gas-fuel ratio control system for an engine |
| GB2467947A (en) * | 2009-02-20 | 2010-08-25 | Rcv Engines Ltd | Rotary valve internal combustion engine |
| US20110073083A1 (en) * | 2009-09-30 | 2011-03-31 | Kubota Corporation | Blow-by gas recirculating apparatus for an engine |
| JP2015206342A (en) * | 2014-04-23 | 2015-11-19 | トヨタ紡織株式会社 | Pcv valve and pcv device including the same |
-
2018
- 2018-09-06 GB GB1814524.3A patent/GB2576912A/en not_active Withdrawn
-
2019
- 2019-01-18 TW TW108101974A patent/TW202010928A/en unknown
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1530034A (en) * | 1975-03-25 | 1978-10-25 | Nissan Motor | Combination of a crankcase ventilation system and a charge gas-fuel ratio control system for an engine |
| GB2467947A (en) * | 2009-02-20 | 2010-08-25 | Rcv Engines Ltd | Rotary valve internal combustion engine |
| US20110073083A1 (en) * | 2009-09-30 | 2011-03-31 | Kubota Corporation | Blow-by gas recirculating apparatus for an engine |
| JP2015206342A (en) * | 2014-04-23 | 2015-11-19 | トヨタ紡織株式会社 | Pcv valve and pcv device including the same |
Also Published As
| Publication number | Publication date |
|---|---|
| GB201814524D0 (en) | 2018-10-24 |
| TW202010928A (en) | 2020-03-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |