The present disclosure generally relates to engines for vehicles, including an oil management system for an engine assembly for off-road vehicles.
An internal combustion engine of a vehicle converts thermal energy into mechanical energy to drive moving parts of the vehicle, thereby enabling motion of the vehicle. Depending on the type of vehicle, designs and structures of the engine may vary to suit the purposes and parameters of the intended vehicle. For instance, off-road vehicles, such as all-terrain vehicles (ATV), side-by-side utility terrain vehicles (UTV or side-by-side), and snowmobiles use internal combustion engines to propel the vehicle. Typically, a four-stroke internal combustion engine (ICE) includes an oil reservoir underneath or at the bottom of the crankcase. This arrangement may be used in a wet sump system where the oil reservoir underneath the crankcase collects oil for a single pump to distribute through the engine. In such a configuration, the wet sump is located at the lowest portion of the engine.
In the conventional wet sump system, the oil reservoir underneath the crankcase adds height to the engine envelope because the total height of the engine must accommodate the height of the oil reservoir underneath the crankcase. This added height positions the weight of the engine farther away from the center of mass of the vehicle or at least higher in the vehicle.
Furthermore, conventional engines generate blow-by gases that include oil. If the oil in the blow-by gases is permitted to leave the engine, such arrangement would result in pollution, reduced performance of the engine, and depletion of the lubricating oil.
The present disclosure is directed toward an engine assembly of a vehicle. The engine assembly has a crankcase that includes a crankshaft. The engine assembly also includes an oil reservoir to receive oil from the crankcase. The oil reservoir is external to and rearward of the crankcase.
In some embodiments, the vehicle includes a snowmobile or an off-road vehicle. In some embodiments, the oil reservoir is positioned within a space between the crankcase and a tunnel for a track drive of the snowmobile or a transmission of the off-road vehicle. In some embodiments, the engine assembly comprises a dry sump, four-stroke engine.
In some embodiments, the engine assembly includes an oil collection pan coupled to the crankcase. The oil collection pan is configured to receive oil from the crankcase. At least one scavenge pump is configured to pump the oil from the oil collection pan. In some embodiments, the at least one scavenge pump is positioned within the crankcase and forward of the crankshaft. In some embodiments, the at least one scavenge pump includes at least one suction tube extending rearwardly to a lowest point of the oil collection pan. In some embodiments, the engine assembly is tilted toward the rear of the vehicle such that the lowest point of the oil collection pan is located at an opening of the at least one suction tube during operation of the vehicle.
In some embodiments, the at least one scavenge pump is located above the opening of the at least one suction tube. The oil collection pan includes an outlet for oil to pass from the at least one scavenge pump out of the oil collection pan.
In some embodiments, the engine assembly further includes a feed pump to pump oil through the engine assembly and includes a drive mechanism to drive the feed pump and the at least one scavenge pump with the crankshaft. In some embodiments, the drive mechanism includes an oil pump shaft to drive the feed pump and a gear train coupled to the oil pump shaft to drive the at least one scavenge pump. In some embodiments, the oil pump shaft passes through the feed pump. In some embodiments, the drive mechanism further includes a sprocket coupled to a first end of the oil pump shaft. In some embodiments, the sprocket couples to the crankshaft with a chain. In some embodiments, the gear train includes a first gear coupled to a second end of the oil pump shaft and includes a second gear coupled to the at least one scavenge pump. In some embodiments, the drive mechanism includes a scavenge pump shaft coupled to the second gear of the gear train. In some embodiments, the scavenge pump shaft drives the at least one scavenge pump.
In some embodiments, the engine assembly includes a cylinder head to cover at least one cylinder. The engine assembly also includes a valve cover that is configured to mount on top of the cylinder head for housing a valve assembly. The valve cover is configured to cover the top of the cylinder head. The valve cover defines a valve chamber. In some embodiments, the engine assembly further includes an oil separator configured to be secured to the cylinder head within the valve chamber. In some embodiments, the oil separator is configured to separate oil from a blow-by gas exiting the engine assembly through an outlet.
In some embodiments, the oil separator shields the outlet from oil splashing within the valve chamber. In some embodiments, the oil separator is configured to define a circuitous route for the oil and blow-by gas to enter the outlet. In some embodiments, the oil separator is configured to define at least one gap with the valve cover. In some embodiments, the blow-by gas and oil to pass through the at least one gap. In some embodiments, the oil separator to reduce speed of the blow-by gas and oil upon entering an oil separation volume. In some embodiments, the oil to separate from the blow-by gas in response to the reduced speed. In some embodiments, the engine assembly with the oil separator provides a wet sump, four-stroke engine.
Preferred embodiments of the present disclosure are described in detail below with reference to the following drawings.
An engine assembly in accordance with the principles of the present disclosure is generally indicated at reference number 102 in the Figures of the attached drawings, wherein numbered elements in the Figures correspond to like numbered elements herein.
The disclosures of the following applications are hereby incorporated by reference: Application Ser. No. 63/537,179, filed Sep. 7, 2023; Application Ser. No. 63/543,461, filed Oct. 10, 2023; and Application Ser. No. 63/528,411, filed Jul. 23, 2023.
The present disclosure relates to engine assemblies of an off-road vehicle, represented as 100.
In some embodiments, the vehicle 100 is a snowmobile (see, e.g.,
In some embodiments, the vehicle 100 is an off-road vehicle such as an ATV or UTV. As with the snowmobile, a similar situation occurs with a side-by-side off-road vehicle. The height of the overall engine envelope can be reduced with the oil reservoir 308 positioned rearward of the crankcase 400, such as between the transaxle assembly and the crankcase. Thus, in some embodiments, the oil reservoir 308 is positioned within the space 300 between the engine crankcase 400 and a transmission of the off-road vehicle.
In some embodiments, the engine assembly 102 is tilted toward the rear of the vehicle 100. In some embodiments, the engine vertical axis (A1) extends through the crankshaft and is oriented with an angle (α1) with respect to the vertical axis (V1) of the vehicle 100 (see, e.g.,
In some embodiments, the oil reservoir 308 attaches to a rear exterior surface of the engine (see, e.g.,
In some embodiments, the oil reservoir 308 receives oil from the crankcase 400 via a first fluidic conveyance system (e.g., tubing) (not shown). Furthermore, in some embodiments, the oil reservoir 308 supplies oil back to the engine assembly 102 via a second fluidic conveyance system (not shown). Thus, in some embodiments, the oil reservoir 308 is used to store oil that is recirculated through the engine assembly 102. See further description below in connection with
In some embodiments, the oil reservoir 308 is nested between the rear of the engine crankcase 400 and the front of the snowmobile tunnel 302 (see, e.g.,
As shown in
Note in
As shown in
A similar arrangement can be had with an off-road vehicle (e.g., ATV, UTV, etc.) by having the oil reservoir 308 positioned between the engine and transmission or transaxle. In some embodiments, the oil reservoir 308 couples the transmission or transaxle to the engine.
In some embodiments, the oil reservoir 308 is part of a dry-sump system for lubricating engine components (see, e.g.,
In some embodiments, the engine assembly 102 includes an oil reservoir 501 (see, e.g.,
As shown in
In some embodiments, the engine assembly 102 includes at least one scavenge pump configured to pump the oil from the oil collection pan 500 (see, e.g.,
In a typical engine configuration that uses a dry sump, the scavenge pumps are situated below the crankshaft in the lowest part of the engine. As the scavenge pumps occupy some space, this arrangement increases the height of the overall engine package. In some embodiments of the present disclosure, the scavenge pumps 600A, 600B are positioned within the crankcase 400. In an illustrative example, an air plenum is positioned on top of the cylinder head and positioning the scavenge pumps 600A and 600B within the crankcase 400 provides sufficient clearance for the engine assembly to fit within a welded frame assembly. In some embodiments of the present disclosure, the scavenge pumps 600A. 600B are positioned within the crankcase 400 forward of the crankshaft 1000. In some embodiments of the present disclosure, the scavenge pumps 600A, 600B are positioned within the crankcase 400 forward of the crankshaft 1000 and the coolant pump 106 rotational axis.
In some embodiments, the scavenge pumps 600A, 600B include at least one suction tube 602A, 602B extending rearwardly to a lowest point 502 of the oil collection pan 500 (see, e.g.,
As shown in
In some embodiments, the oil collection pan 500 includes an outlet 800 for oil to pass from the scavenge pumps 600A, 600B out of the oil collection pan 500. In some embodiments, the outlet 800 defines an opening (e.g., a bore) to allow oil to flow out of the oil collection pan 500 (see, e.g.,
In some embodiments, the engine assembly 102 includes a feed pump 900 to pump oil through the engine assembly 102 to lubricate, clean, and cool moving parts. The feed pump (or main oil pump) 900 is preferably a gear rotor type with an inner rotor and an outer rotor. The feed pump 900 is housed within the crankcase. In some embodiments, the feed pump 900 pumps oil through the oil supply line 904 to lubricate various engine components such as the crankshaft 1000, pistons 1002A, 1002B, 1002C, camshafts 1004A, 1004B, and the valve assembly 1006 (see, e.g.,
In some embodiments, the engine assembly 102 includes a drive mechanism 1008 to drive the feed pump 900 and the at least one scavenge pump 600A, 600B with the crankshaft 1000. In some embodiments, the drive mechanism 1008 includes an oil pump shaft 902 to drive the feed pump 900 (see, e.g.,
In some embodiments, the drive mechanism 1008 includes a gear train 1018 coupled to the oil pump shaft 902 to drive the at least one scavenge pump 600A, 600B. In some embodiments, the gear train 1018 includes a first gear 1020 coupled to a second end 1014 of the oil pump shaft 902. In some embodiments, the gear train 1018 also includes a second gear 1022 coupled to the at least one scavenge pump 600A, 600B. In some embodiments, the first gear 1020 is entrained with the second gear 1022 such that rotation of the first gear 1020 causes the second gear 1022 to rotate. In some embodiments, a scavenge pump shaft 1024 is coupled to the second gear 1022. In some embodiments, the scavenge pump shaft 1024 drives the scavenge pumps 600A, 600B. In some embodiments, different gear ratios are used for the gear train 1018 to cause the scavenge pumps 600A, 600B to operate at different speeds relative to the feed pump 900.
Referring now to
The engine assembly 1300 includes a cylinder head 1306 to cover at least one cylinder 1602A, 1602B, 1602C (see, e.g.,
In some embodiments, a blow-by gas exits the engine assembly 1300 through an outlet 1304. In some embodiments, the outlet 1304 provides the blow-by gas to a blow-by gas system that recirculates the blow-by gas back to an air intake of the engine assembly 1300 for combustion. Because the blow-by gas includes aerosolized oil, this oil would, if not for the present disclosure, otherwise be burned and lost by the re-combustion of the blow-by gas, thus decreasing the efficiency of the engine.
The oil separator 1402 is configured to separate oil from the blow-by gas exiting the engine assembly 1300 through the outlet 1304. In some embodiments, the oil separator 1402 shields the outlet 1304 from oil splashing within the valve chamber 1410. In some embodiments, the oil separator 1402 includes a solid, impermeable structure (e.g., a baffle, wall, or others) that prevents oil droplets from passing through it.
The engine assembly 1300 includes an oil separator 1402 configured to be secured to the cylinder head 1306 within the valve chamber 1410 (see, e.g.,
In some embodiments, the oil separator 1402 is positioned at one side of the cylinder head 1306 between the camshafts 1404A, 1404B in front of the outlet 1304 such that the flow of the blow-by gas and oil must go around the oil separator 1402. In some embodiments with a single camshaft, the oil separator 1402 is positioned near the end of the camshaft in front of the outlet 1304.
In addition to blocking splashing oil, the oil separator 1402 in some embodiments facilitates separation of aerosolized oil from the blow-by gas. In some embodiments, the oil separator 1402 is configured to define a circuitous route 1804 for the oil and blow-by gas to enter the outlet 1304 (see, e.g.,
As the blow-by gas and oil flow through the gaps 1802A, 1802B, 1802C, the area through which the blow-by gas and oil flow is reduced, resulting in an increased speed in the blow-by gas and oil flow through the gaps 1802A, 1802B, 1802C. However, the blow-by gas and oil reduce speed upon entering the oil separation volume 1806. The oil separates from the blow-by gas in response to the reduced speed in the oil separation volume 1806. In some embodiments, the circuitous route 1804 provides surfaces 1808 for the oil to contact and separate from the blow-by gas. The separated oil may collect within the oil separation volume 1806. Thus, upon slowing down within the oil separation volume 1806, the oil drains down one or more surfaces 1808 in response to the reduced speed.
In some embodiments, the oil separator 1402 is configured to define at least one drain gap 1810 with the valve cover 1302. In some embodiments, the bottom of the oil separator 1402 is offset from the valve cover 1302 to form a drain gap 1810. Separated oil may pass out of the oil separation volume 1806 through the at least one drain gap 1810 to an oil reservoir (e.g., an oil collection pan, wet sump, or others). By separating the oil from the blow-by gas, the oil separator 1402 facilitates reduced oil consumption by the blow-by system.
Turning now to
The fasteners used throughout the present disclosure may be nut and bolt fasteners used in automobile industry. In some embodiments, the bolt in such fasteners may have a hex-head, followed by a hex-headed cap screw and a stud.
It is to be noted that different values and parameters mentioned in the description are not intended to bound the specification in any manner.
As used herein, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The terms “front,” “forward,” “rear,” and “rearward” are defined relative to the steering mechanism, such as a steering wheel, and the portion of the driver seat that is farthest from such steering mechanism. The terms “front” and “forward” indicate the direction from the portion of the driver seat farthest from the steering mechanism toward the steering mechanism. The terms “rear” and “rearward” indicate the direction from the steering mechanism toward the farthest portion of the driver seat. The terms “height,” “vertical,” “upper,” “lower,” “above,” “below,” “top,” “bottom,” “topmost,” and “bottom-most” are defined relative to vertical axis of the vehicle. The vertical axis is non-parallel to the longitudinal axis and is defined as parallel to the direction of the earth's gravity force on the vehicle when the vehicle is on horizontal ground. The term “lateral” is defined relative to the lateral axis of the vehicle. The lateral axis is non-parallel to the longitudinal and vertical axes. The longitudinal axis extends forward and rearward through the vehicle in a horizontal plane.
The term “configured” as used herein means an element being one or more of sized, dimensioned, positioned, or oriented to achieve or provide the recited function or result. The term “directly coupled” as used herein means that a component contacts (for example, when bolted) or is welded to another component. The term “indirectly coupled” as used herein means that a first component is coupled to a second component by way of one or more intervening components that are directly coupled to the first and second components. A first component that is indirectly coupled to a second component is directly coupled to a third component, which may be directly coupled to the second component or to a fourth component that is directly coupled to the second component. The term “coupled” should therefore be understood to disclose both direct and indirect coupling of components or elements that are described as being coupled to each other.
Reference in the specification to “one embodiment” or “an embodiment” is intended to indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least an embodiment of the invention. The appearances of the phrase “in one embodiment” or “an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
The term “engine assembly” used throughout the disclosure refers to an engine having a cylinder head, a cylinder block, a crankshaft, camshafts, a camshaft drive or a timing chain, a valve cover, and other associated parts.
The term “or” is an inclusive grammatical conjunction to indicate that one or more of the connected terms may be employed. For example, the phrase “one or more A, B, or C” or the phrase “one or more As, Bs, or Cs” is employed to discretely disclose each of the following: i) one or more As, ii) one or more Bs, iii) one or more Cs, iv) one or more As and one or more Bs, v) one or more As and one or more Cs, vi) one or more Bs and one or more Cs, and vii) one or more As, one or more Bs, and one or more Cs. The term “based on” as used herein is not exclusive and allows for being based on additional factors not described. The articles “a,” “an,” and “the” include plural references. Plural references are intended to also disclose the singular.
While preferred embodiments have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Each disclosure of a component preferably having a feature or characteristic is intended to also disclose the component as being devoid of that feature or characteristic unless the principles of the invention clearly dictate otherwise. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow. It should also be noted that the claim dependencies or combinations of elements recited in the claims does not reflect an intention to forgo claiming other subject matter disclosed herein. Instead, this disclosure is intended to also disclose the subject matter of any combination of any two or more of the claims, such that subsequent claim sets may recite that any one of the dependent claims depends from any other one or more claims, up to and including all other claims in the alternative (such as “The apparatus or method of any one of the preceding or subsequent claims . . . ”). This disclosure is also intended to disclose the subject matter of any one of the dependent claims, as if it were an independent claim, with or without all or a portion of the subject matter of the original independent claim(s) or any other subject matter disclosed herein.
This application claims the benefit of priority from U.S. Provisional Patent Application Nos. 63/545,106 filed Oct. 20, 2023; 63/544,072 filed Oct. 13, 2023; 63/542,865 filed Oct. 6, 2023; and 63/468,357 filed May 23, 2023, the contents of which are incorporated herein by reference.
Number | Date | Country | |
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63545106 | Oct 2023 | US | |
63544072 | Oct 2023 | US | |
63542865 | Oct 2023 | US | |
63468357 | May 2023 | US |