This invention relates generally to internal combustion engines, and more particularly to engines using rotary valves.
Internal combustion engines are well known and are used in various applications. For example, internal combustion engines are used in automobiles, farm equipment, lawn mowers, and watercraft. Internal combustion engines also come in various sizes and configurations, such as two stroke or four stroke and ignition or compression.
Typically, internal combustion engines (
Accordingly, there remains a need for a valve train for an internal combustion engine with low friction, good reliability, a small number of parts, and capable of being replaced and/or repaired in the field quickly and easily.
This need is addressed by the present invention, which provides a valve train made up of individual rotating valve assemblies that may be removed one at a time and replaced with new rotating valve assemblies quickly and easily.
According to one aspect of the technology, a valve assembly includes a housing having an internal cavity, an open top, and an open bottom, the open top and open bottom being in fluid communication with the internal cavity; a valve barrel positioned in the internal cavity and adapted for rotation therein, the valve barrel having an annular peripheral surface and an aperture extending transversely therethrough communicating with the peripheral surface on opposite sides; a first seal assembly positioned in the open top and a second seal assembly positioned in the open bottom, wherein the first and second seal assemblies each include a seal having a sealing surface in mating engagement with the peripheral surface and an aperture extending therethrough, the aperture having a size and shape substantially equal to the aperture in the valve barrel to permit flow therethrough; and wherein when the aperture of the valve barrel is in alignment with the apertures of the first and second seal assemblies, gas is permitted to flow through the valve assembly.
According to another aspect of the technology, a cylinder head assembly includes at least one intake valve assembly pocket defined by upper and lower cylinder head sections and at least one exhaust intake valve assembly pocket defined by the upper and lower cylinder head sections; at least one intake valve assembly positioned in the at least one intake valve assembly pocket and at least one exhaust valve assembly positioned in the at least one exhaust valve assembly pocket, the at least one intake valve assembly and at least one exhaust valve assembly each includes: a housing having an internal cavity, an open top, and an open bottom, the open top and open bottom being in fluid communication with the internal cavity; a valve barrel positioned in the internal cavity and adapted for rotation therein, the valve barrel having an annular peripheral surface and an aperture extending transversely therethrough communicating with the peripheral surface on opposite sides; a first seal assembly positioned in the open top and a second seal assembly positioned in the open bottom, wherein the first and second seal assemblies each include a seal having a sealing surface in mating engagement with the peripheral surface and an aperture extending therethrough, the aperture having a size and shape substantially equal to the aperture in the valve barrel to permit flow therethrough; and wherein when the aperture of the valve barrel is in alignment with the apertures of the first and second seal assemblies, gas is permitted to flow through the valve assembly.
The invention may be best understood by reference to the following description taken in conjunction with the accompanying drawing figures in which:
Referring to the drawings wherein identical reference numerals denote the same elements throughout the various views,
The illustrated example is an eight-cylinder engine 10 of vee configuration, commonly referred to as a “V-8”, with two banks of four cylinders set 90 degrees to each other. However, it will be understood that the principles of the present invention are applicable to any internal combustion engine, for example engines running various cycles such as Otto or Diesel cycles, or similar machines requiring valves to open and close fluid flow ports.
The engine includes a block 12 which serves as a structural support and mounting point for the other components of the engine 10. Generally cylindrical cylinder bores 14 are formed within the block 12. As noted above, the cylinder bores 14 are arranged in two longitudinal cylinder banks 16 of four cylinder bores 14 each. A crankshaft 18 having offset crankpins 20 is mounted in the block 12 for rotation in suitable bearings. A piston 22 is disposed in each cylinder bore 14, and each piston 22 is connected to one of the crankpins 20 by a piston rod 24. The crankshaft 18, piston rods 24, and pistons 22 collectively define a rotating assembly 26. In operation, gas pressure in the cylinder bores 14 causes linear movement of the pistons 22, and the rotating assembly 26 is operable in a known manner to convert linear movement of the pistons to rotation of the crankshaft.
The engine includes one cylinder head assembly 28 attached to each cylinder bank 16. The cylinder head assembly 28 has a generally concave combustion chamber 30 formed therein corresponding to and aligned with each cylinder bore 14. Collectively, each cylinder bore 14 and the corresponding combustion chamber 30 defines a cylinder 32.
The cylinder head assembly 28 has a plurality of intake ports 34 formed therein; each intake port 34 extends from one of the combustion chambers 30 to an intake plane 36 at an exterior surface of the cylinder head assembly 28. As will be described in detail below, an intake valve barrel 38 of a rotating valve assembly 39,
The cylinder head assembly 28 also includes a plurality of exhaust ports 42 formed therein; each exhaust port 42 extends from one of the combustion chambers 30 to an exhaust plane 44 at an exterior surface of the cylinder head assembly 28. As will be described in detail below, an exhaust valve barrel 46 of a rotating valve assembly 47,
The engine 10 includes a fuel delivery system 50 which is operable to receive an incoming airflow, meter a hydrocarbon fuel such as gasoline into the airflow to generate a combustible intake mixture, and deliver the intake mixture to the cylinders 32.
The fuel delivery system 50 may be continuous flow or intermittent flow, and the fuel injection point may be at the individual cylinders 32 or at an upstream location. Optionally the fuel injection point may be within the cylinders 32, a configuration commonly referred to as “direct injection”, in which case the intake ports 34 deliver only air to the cylinders 32. Known types of fuel delivery systems include carburetors, mechanical fuel injection systems, and electronic fuel injection systems. The specific example illustrated is an electronic fuel injection system with one intake runner 52 connected to each intake port 34.
The engine 10 includes an ignition system comprising one or more spark plugs 54 mounted in each combustion chamber 30, to ignite the intake mixture. An appropriate ignition power source is provided, such as a conventional Kettering ignition system with a coil and distributor, or a direct ignition system with a trigger module and multiple coils. The ignition power source is connected to the spark plugs 54, for example with leads 56.
The lower section 58 is a block-like element which may be formed by casting or machining from billet. It includes an exterior surface 62 which incorporates the combustion chambers 30 (see
The upper section 60 is also a block-like element which may be formed by casting or machining from billet. It includes an exterior surface 76, and an opposed interior surface 78 which mates with the interior surface 64 of the lower section 58. The intake ports 34 described above are formed as part of the upper section 60. Adjacent the interior surface 78, the upper section 60 has a plurality of intake valve assembly recesses 69 formed therein, arranged in a longitudinal line (see
Provisions may be incorporated for liquid cooling all or part of the cylinder head 57. In the illustrated example, the upper section 60 includes a hollow interior chamber (not shown) disposed between the interior surface 78 and the exterior surface 76. A series of coolant inlet holes 77 (
The lower section 58 and upper section 60 receive a plurality of intake valve assemblies 39 and a plurality of exhaust valve assemblies 47. It should be appreciated that for a single cylinder engine, a single intake valve assembly 39 and a single exhaust valve assembly 47 would be used. The valve assemblies 39 and 47 are generally similar in construction to each other, with the intake valve assembly 39 being slightly larger in scale. The construction of the intake valve assembly 39 will be described in detail, with the understanding that the details are applicable to both of the valve assemblies 39, 47.
Referring to
The lateral dimension of the intake aperture 40 (perpendicular to axis 82), the diameter of the intake valve barrel 38, and the rotational speed of the intake valve shaft 80A relative to the crankshaft speed all effect the valve open time or “duration”, and these effects are inter-related. This is also true for the exhaust valve barrels 46. These variables may be manipulated in order to adapt the intake valve shaft 80A and/or exhaust valve shaft 80B to suit a particular application. For example, the intake valve barrels 38 could be a different diameter than the exhaust valve barrels 46. In one non-limiting example, the ratio of the diameter of the intake valve barrels 38 to the diameter of the exhaust valve barrels 46 could be about 1:1 to about 4:1.
The intake valve barrel 38 may be made from a rigid, wear-resistant material such as a metal alloy or ceramic. A wear coating such as ceramic or carbide may be applied to all or part of the intake valve barrel 38, particularly the peripheral surface 84, to improve its wear properties.
Optionally, longitudinal holes 92 or other openings may be formed in the intake valve barrel 38 extending between the forward and aft end faces 86, 88. These holes 92 may be used to reduce the mass of the intake valve barrel 38, for balancing purposes, and/or to provide a cooling air flow.
A cylindrical forward stub shaft 94 extends from the forward end face 86, and a cylindrical aft stub shaft 96 extends from the aft end face 88.
The stub shafts 94, 96 may include mating mechanical alignment features to transfer torque between two adjacent intake valve barrels 38 and to maintain a specific angular relationship therebetween. It will be understood that the intake aperture 40 of each intake valve barrel 38 must have a specific angular orientation which is dependent on the cylinder firing sequence of the engine 10. The mechanical alignment feature described above may be configured so that any intake valve barrel 38 may be used in any location within the intake valve shaft 80A, that is, the mechanical alignment feature may accommodate multiple angular alignments, or alternatively the mechanical alignment feature may be configured to produce only a single angular alignment, in which case each intake valve barrel 38 would need to be placed in a specific location within the intake valve shaft 80A.
Seals 102 are positioned on each stub shaft 94, 96 and pressed into apertures 104, 106 of the housing 83 to provide sealing along ends of the valve barrel 38. The housing 83 also includes an open top 108 and an open bottom 110 to receive valve seal assemblies 112. As shown, the housing 83 includes an internal cavity 109 in fluid communication with the open top 108 and open bottom 110 as well as apertures 104 and 106. As shown, the housing 83 is of a rectangular configuration to match a size and shape of valve assembly recesses 66 and 72 of the cylinder head 57 and provide a tight fit therein; however, it should be appreciated that the housing 83 and valve assembly recesses 66 and 72 may have other suitable matching configurations. As illustrated, the valve seal assemblies 112 are used in both the open top 108 and open bottom 110; thus, only a single assembly will be discussed.
The seal assembly 112 includes a seal 114 having a concave valve barrel mating surface 116, an aperture 118 having a size (within 10%) and shape substantially equal to the intake aperture 40 to permit flow therethrough, and a backer plate 120. The seal 114 may be made of any suitable material capable of providing a seal and wear resistance such as a graphite material. The backer plate 120 includes a ring seal slot 122 for receiving ring seal 124 therein. Ring seal 124 provides additional sealing to prevent gases from escaping between the backer plate 120 and cover 126. Ring seal 124 may have suitable cross-sectional shape to allow the ring seal 124 to contract and expand during operation, thereby allowing the seal 114 to float along the barrel 38 as it expands during operation from heat. For example, the ring seal 124 may have a c-shaped cross section.
Cover 126 includes a corresponding ring seal slot 128 for receiving the ring seal 124 therein and compressing the seal 124 between the backer plate 120 and the cover 126 when assembled. Cover 126 also includes an aperture 130 extending therethrough to allow gases to flow through the barrel 38, the seal 114 and the cover 126 from the intake port 34 into combustion chamber 30 (i.e. in fluid communication). The cover 126 further includes a housing slot 132 for receiving housing projection 134 (continuous projections around a periphery of the open top 108 and open bottom 110) therein, thereby securing the cover 126 to the housing 83 and maintaining the seal assembly 112 in the open top 108 or open bottom 110.
Referring to
As shown, seals 202 incorporate a bearing surface 304; however, it should be appreciated that other types of bearings may be used to allow the valve barrel 238 to rotate relative to the cylinder head 57. For example, other suitable bearings may be roller bearings.
The backer plate 220 includes a raised ridge 298 extending from a rear surface 300 of the backer plate 220. The ridge 298 is adapted for mating engagement with recesses 302 formed in the upper 60 and lower 58 sections of the cylinder head 57. For clarity, only the upper section 60 is shown. The mating engagement between the ridge 298 and recesses 302 provides a labyrinth-type arrangement which disperses pressure from the cylinder during combustion, thereby reducing the amount of pressure seen by ring seal 124. Further, as pressurized gas migrates through the labyrinth-type arrangement created by the recesses 302 and ridge 298, a small amount of residual gas is trapped and presses against the ridge 298. This causes the seal 214 to be pressed against the valve barrel 238, thereby increasing sealing between the seal 214 and peripheral surface 284 of the valve barrel 238.
As illustrated, recesses 306 are also formed in the upper 60 and lower 58 sections of the cylinder head 57. Recess 306 surrounds recess 302 and is adapted to receive ring seal 124 therein. Thus, unlike valve assembly 39, ring seal 124 is not sandwiched between the backer plate 220 and a cover; rather, when installed, ring seal 124 is compressed between the rear surface 300 of the backer plate 220 and the recess 306 of the cylinder head 57 and is positioned around the raised ridge 298.
For clarity, only valve assemblies 39 and 47 are discussed below; however, it should be appreciated that the general description also applies to valve assembly 239. In use, valve assemblies 39 and 47 are assembled and pre-packaged for use. When one of the valve assemblies 39, 47 fail, a user simply decouples the failed valve assembly 39, 47 from the respective valve shaft 80A, 80B and replaces the failed valve assembly 39, 47 with a new valve assembly 39, 47 which simply drops into a respective valve assembly recess 66, 72 and couples the valve assembly 39, 47 to the shaft 80A, 80B.
In the assembled engine, a drive assembly 140 (
The operation of the engine 10 will be described with reference to
The apparatus described above has several advantages over the prior art. The rotary valve structure has significantly lower parts count and frictional losses as compared to a conventional poppet valve-train. The rotary valve structure also has the potential to be much more reliable than a conventional valve-train because it does not require reciprocating movement and does not rely on highly-stressed valve springs for operation at high engine speeds.
Furthermore, the sealing assembly described herein will provide effective sealing of the rotating valve assembly while permitting low mechanical loads and long component life.
It will be understood that the present invention may be implemented as a complete engine, or that the cylinder head assemblies described herein may be retrofitted to an existing internal combustion engine, or that the rotating valve assembly may be incorporated into a cylinder head design.
The foregoing has described an engine with rotating valve assembly. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
Each feature disclosed in this specification (including any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
The invention is not restricted to the details of the foregoing embodiment(s). The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
Number | Date | Country | |
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62557800 | Sep 2017 | US |