Patent Grant
10851741
The examples provided herein relate to engines, for example, internal combustion engines for automobiles and/or motorcycles, and, more particularly, to air cleaner base assemblies that couple an air cleaner to a carburetor or fuel injection system and provide conduits for venting blow-by gases from the crankcase into an air intake thereof or a reservoir attached thereto.
As internal combustion engines wear, the annular spaces between the pistons and the cylinder tend to increase. In the combustion chamber of each cylinder, an air-fuel mixture is ignited. The expanding gas mixture forces the piston away from the engine head or closed end of the cylinder (typically generally downward in most reciprocating internal combustion engine configurations) generating power in the engine. In the expansion process, part of the gas mixture is forced through the annular spaces between the piston and the cylinder into the crankcase. These “blow-by” gases, which also include oil mist (which can coalesce into droplets) and unburned fuel, accumulate in the crankcase and must be vented from the crankcase to the atmosphere to prevent a potentially dangerous pressure build-up in the crankcase.
Pollution control laws and regulations restrict the emissions from internal combustion engines. As exhaust gases from internal combustion engines have become cleaner, the blow-by gases have become a more significant fraction of the total pollution generated by internal combustion engines. In many localities, the pollution control laws and regulations are such that vapors from the crankcase of internal combustion engines must be cleaned prior to discharge into the atmosphere. One method of reducing the pollution associated with the blow by gases is to recycle the gases through the engine. In some four-cycle, two-cylinder engines manufactured by Harley-Davidson, crank case venting and cleaning is accomplished by a crankcase breather system that conducts blow-by gases from the crankcase to an air cleaner, from which the gases are recirculated back into the engine through the carburetor for burning in the engine cylinders. A crankcase breather system is also used for engines employing a fuel injection system.
By way of example, in Harley-Davidson four-cycle, two-cylinder engines, each cylinder includes a pair of push rods that extend from the crankcase into the cylinder head for operating the intake and exhaust valves. Each of the push rods is disposed within a hollow push rod tube that communicates with the crankcase (i.e., provides a passageway for blow-by gases in the crankcase). Upper ends of the push rod tubes communicate with a chamber in the middle rocker box of each cylinder head. On each downstroke of the piston in each cylinder, an umbrella valve attached to a center rocker spacer opens, permitting blow-by gases to pass into the middle chamber. From the middle chamber, the blow-by gases are conducted to a second, upper chamber in the rocker box, and thence, via passageways, through a pair of spaced-apart, threaded holes in a right side of the cylinder heads. The threaded holes in combination with hollow bolts enable a stock plastic backing plate to be secured to the cylinder heads. The hollow bolts provide a passageway for the blow-by gases to vent from the holes in the cylinder heads. In a stock version of the Harley Davidson engine with a carburetor, a stock plastic carburetor backing plate is provided to conduct the blow-by gases from the hollow bolts to an air cleaner element.
To improve and customize engine performance, many purchasers of Harley Davidson motorcycles owners remove and discard the stock carburetor and backing plate system and replace it with a substitute crankcase breather system. These substitute crankcase breather systems can improve air flow to the engine and thereby can significantly improve the horse power of the engine within certain operational ranges.
Some substitute crankcase breather systems vent blow-by gases, which contain oil and fuel mist, directly into the air cleaner, resulting in premature fouling of the air cleaner which substantially increases replacement frequency of the air cleaner. Other substitute crankcase breather systems vent blow-by gasses from multiple cylinder heads in a manner that causes them to interfere with one another. For example, where blow-by gases are vented into a common channel, the portions vented during the piston downstroke in one cylinder can interfere with the outflow of blow-by gases from the other cylinder during its piston upstroke.
For the purposes of promoting an understanding of the principles of the present disclosure, reference will now be made to the examples illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of this disclosure is thereby intended.
The backing plate 130 includes a first side 132 and a second side 134. The first side 132 is configured to be coupled to the engine 5. The backing plate 130 further includes a venturi portion 140 defining an intake aperture 141 extending from the first side 132 to the second side 134. In an example, the intake aperture 141 is aligned with the air intake port 21 of the engine 5 when the support member 130 is coupled to the engine 5 such that air may flow through the intake aperture 141 and into the engine 5 through the air intake port 21. In another example, a cross-sectional area of the intake aperture 141 is substantially the same size to a cross-sectional area of the air intake port 21. In such an example, the cross-sectional area of the intake aperture 141 on the first side 132 of the backing plate 130 is substantially similar to the cross-sectional area of the air intake port 21. The second side 134 of the backing plate 130 is configured to be coupled to the filter assembly 180. The backing plate 130 also includes at least one flange 150, 160 for coupling the backing plate 130 to the engine 5. In some examples, the at least one flange 150, 160 couples to a respective cylinder head 12, 14 of the engine 5. In other examples, the at least one flange 150, 160 couples to a respective communication port 18, 20 of the cylinder head 12, 14. In some examples, the at least one flange 150, 160 is coupled to the respective communication port 18, 20 with a bolt 170 that extends through the at least one flange 150, 160 and is received by the respective communication port 18, 20. In some examples, the bolt 170, a portion of the at least one flange 150, 160, and/or the communication port 18, 20 are threaded such that opposed surfaces engage and contact one another and the bolt 170 is configured in such a manner to allow blow-by gasses to pass therethrough (explained in more detail with respect to
The filter assembly 180 includes an air filter 182 and a cover 184. In some examples, when the filter assembly 180 is coupled to the backing plate 130 and the backing plate 130 is coupled to the engine 5, exterior air may pass through the filter assembly 180, through the intake aperture 141, and into the engine 5 through the air intake port 21. In some examples, the filter assembly 180 is secured to the backing plate 130 with at least one alignment bolt 186. The alignment bolt 186 may pass through the backing plate 130 and into the engine 5 or may only extend into the backing plate 130 and not the engine 5. In an example, the air filter 182 includes an alignment hole 183 for each alignment bolt 186. In such an example, the alignment bolt 186 extends into the alignment hole 183 of the air filter 182 to couple the air filter 182 to the alignment bolt 186 and/or the backing plate 130. The cover 184 may then fit over the air filter 182 and couple to either the backing plate 130 and/or the air filter 182.
The reservoir 210 may include a top side 211, a guide surface 212, a lip 213, a receptacle 214, a receptacle opening 215, a first side 216 having a first surface 217, a gasket 218, and a second side 222 having a second surface 223. In examples where the reservoir 210 is removably couplable to the backing plate 130, the reservoir 210 may include an attachment device 220 that removably couples the reservoir 210 to the backing plate 130. In the illustrated example, the attachment device 220 is a screw that passes through the reservoir 210, the gasket 218, and is received by the backing plate 130. The reservoir 210 is designed to collect blow-by gasses and/or the oil droplets included therein that do not make it through the intake aperture 141 and into the air intake port 21. For example, droplets of oil (not shown) may traverse and/or fall along the venturi portion 140 and/or second side 134 of the backing plate 130 and into the receptacle 214 of the reservoir 210. In some examples, the droplets of oil pass through the receptacle opening 215 and into the receptacle 214. The guide surface 212 is located on the top side 211 and is another surface along which oil droplets can traverse to reach the receptacle 214. For example, oil droplets that do not fall directly into the receptacle opening 215 may land on the guide surface 212 and traverse along the guide surface 212 to the receptacle opening 215 and into the receptacle 214. In some examples, the guide surface 212 is angled and/or sloped towards the receptacle opening 215 to promote the oil droplets traverse from guide surface 212 to receptacle 214. In some examples, the guide surface 212 includes the lip 213, which surrounds the guide surface 212 to keep oil droplets on the guide surface 212 until they find the receptacle opening 215 (and thus the receptacle 214). In some examples, the first surface 217 directly couples to the backing plate 130. In other examples, the gasket 218 is coupled between the first surface 217 and the backing plate 130. The gasket 218 improves the liquid tight seal between the first surface 217 and the backing plate 130.
In some examples, the second surface 223 covers the entire second side 222 such that no liquid can escape the receptacle 214 from the second side 222. In some examples, the second side 222 includes a plug (not shown) that can be removed from the reservoir 210 to allow the contents of the receptacle 214 to be emptied. In the illustrated example, the guide surface 212 (and optionally the lip 213) covers the entire top side 211 but for the receptacle opening 215 such that the contents of the receptacle 214 can only escape the top side 211 through the receptacle opening 215. In some examples, the first surface 217 covers the entire first side 216 such that no liquid can escape the receptacle 214 from the first side 216. In the illustrated example, the first surface 217 does not entirely cover the first side 216, thus defining a first side opening 224. In such examples, oil (or other material) collected in the receptacle 214 can escape the receptacle from either the first side 216 (through the first side opening 224) or the receptacle opening 215. In such examples, the first surface 217 couples to the second side 134 of the backing plate 130 such that a liquid-tight seal is created between the first side 216 of the reservoir 210 and the second side 134 of the backing plate 130. In such examples, when the reservoir 210 is coupled to the backing plate 130, the contents of the receptacle 214 can only escape the receptacle 214 through the receptacle opening 215 (or other escape routes described above, such as the plug on the second side 222 of the reservoir 210).
In the illustrated example, the at least one tube 240 includes a tube conduit 250 (
In the illustrated example, the first end 248 of the tubes 240 are located on the venturi portion 140. In the illustrated example, the first end 248 of the tubes 240 are located at about 80 degrees and about 280 degrees on the venturi portion 140, where the topmost point of the venturi portion 140 defines zero degrees and the degrees increase clockwise around the venturi portion 140 until a total of 360 degrees is reached. In other examples, the first end 248 of the tube 240 may be located at any point on the second side 134 of the backing plate 130. In some examples, the first end 248 of the tube 240 is located on a portion of the second side 134 of the backing plate 130 that is not the venturi portion 140. In other examples, the first end 248 of the tube 240 are located between about 60 degrees and about 120 degrees of the venturi portion 140 and/or between about 240 degrees and about 300 degrees of the venturi portion 140. In other examples, the first end 248 of the tube 240 is located between about 30 degrees and about 90 degrees and/or between about 270 degrees and about 330 degrees of the venturi portion 140. In examples where the first end 248 of the tube 240 is located between 270 degrees and 90 degrees (traveling clockwise from 270 degrees to 90 degrees), gravity may assist contents pass through the tube 240.
The tube 240 has a tube length 252 defined as the distance from the first end 248 of the tube 240 to the second end 249 of the tube 240. In some examples, the tube length 252 is less than four inches. In other examples, the tube length 252 is less than three inches. In other examples, the tube length 252 is less than two inches. In other examples, the tube length 252 is less than one inch. In some examples, the intake aperture 141 includes a first side 142 and a second side 144. In some examples, the first side 142 of the intake aperture 141 defines a first plane 133 and the second side 144 of the aperture 141 defines a second plane 135. In some examples, a third plane 137 is defined by the end 151, 161 (see also
In some examples, the tube outlet 244 and/or second end 249 point towards the air intake port 21 of the engine and/or away from the second plane 135. In some examples, the tube outlet 244 and/or second end 249 point in a direction extending from the second plane 135 towards the first and/or third plane 135, 137 and in a direction that is non-parallel to the first plane 133. For example, in the illustrated example, the cross sectional area of the tube outlet 244 defines a fourth plane 139 that is parallel to the first plane 133 and/or second plane 135. In other examples, the fourth plane 139 may be disposed at any non-perpendicular angle to the first plane 133, second plane 135, and/or third plane 137 such that the tube outlet 244 still points in a direction extending from the second plane 135 towards the first plane 133.
In some examples, the inner ring 810 extends through the intake aperture 141. For example, in the illustrated example, the inner ring first side 812 defines an inner ring first end 813 that terminates between the first plane 133 and the third plane 137. In other examples, the inner ring first side 812 terminates between the first plane 133 and the second plane 135. In other examples, the inner ring first side 812 extends past the third plane 137 such that it terminates on the side of the third plane 137 opposite the first and second planes 133, 135. In some examples, the inner ring first side 812 terminates between the first plane 133 and third plane 137 or beyond the third plane 137, in other examples, the inner ring first side 812 extends a horizontal distance 860 from the first side 132 of the backing plate 130. For example, in the illustrated example, the horizontal distance 860 is defined by the distance between the contact surface 260 and the inner ring first side 812. In some examples, the horizontal distance 860 is less than two inches. In some examples, the horizontal distance 860 is less than one inch. In some examples, the horizontal distance 260 is less than 0.5 inches.
In some examples, the inner ring exterior surface 818 is disposed at a distance from the venturi portion 140 and/or intake aperture 141, i.e., the inner ring exterior surface 818 does not contact the venturi portion 140 and/or intake aperture 141, when the donut 800 is coupled to the backing plate 130. For example, a first gap 862 is defined as the distance between the inner ring exterior surface 818 and the first side 142 of the intake aperture 141. In some examples, the first gap 862 is less than about 0.75 inches. In other examples, the first gap 862 is less than about 0.5 inches. In other examples, the first gap 862 is less than about 0.25 inches. In some examples, the first gap 862 is at least 0.055 inches. In other examples, a second gap 864 is defined as the distance between the inner ring exterior surface 818 and the second side 144 of the intake aperture 141. In some examples, the second gap 864 is less than 1.25 inches. In other examples, the second gap 864 is less than 1.0 inches. In other examples, the second gap 864 is less than 0.75 inches. In other examples, the second gap 864 is less than 0.5 inches. In some examples, the second gap 864 is at least 0.340 inches.
The first gap 862 and second gap 864 are important in examples (as depicted in
In some examples, the inner ring 810 is a complete circle, i.e., the inner ring 810 extends around the entire intake aperture 141, such as in the illustrated example. Note, however, that the shape is not limited to a circle, and may be any other geometric shape, such as a square, or other multi-sided polygon. In other examples (not shown), the inner ring 810 only partially encircles the intake aperture 141. In some such examples, the inner ring 810 extends clockwise around the intake aperture 141 from about 30 degrees to about 330 degrees. In other such examples, the inner ring 810 extends clockwise around the intake aperture 141 from about 60 degrees to about 300 degrees. In other examples, the inner ring 810 extends clockwise around the intake aperture 141 from about 90 degrees to about 180 degrees.
While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain examples have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.
This application claims priority benefit of U.S. Provisional Application No. 62/713,429 filed Aug. 1, 2018, which is hereby incorporated in its entirety herein by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5233967 | Peller | Aug 1993 | A |
| 5503649 | Nickel | Apr 1996 | A |
| 6374815 | Ness | Apr 2002 | B1 |
| 20110232983 | Abe | Sep 2011 | A1 |
| 20130220257 | James | Aug 2013 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 62713429 | Aug 2018 | US |
