Patent Application
20100147253
This invention relates to oil pans. More particularly, this invention relates to oil pans for internal combustion engines.
Internal combustion engines include crankcases having a plurality of cylinders. The cylinders contain pistons whose reciprocating motion caused by combustion events are transferred through a crankshaft to yield a torque output of the engine. Often, engine crankcases are made of cast metal and include passages integrally formed therein for the transfer of various fluids from one location of the engine to another. Fluids typically transferred through passages in an engine include coolant, air, fuel, oil, and so forth.
Engines typically use oil for lubrication and/or actuation of various engine components. A typical engine may contain a considerable amount of oil that circulates therethrough during operation of the engine, and that collects in a reservoir when the engine is not operating. The reservoir may also contain engine oil that is not used during operation of the engine. The reservoir is usually connected to an engine, and is typically located close to a lowest point of the engine.
A conventional oil pan assembly includes a lower oil pan, an upper oil pan having a baffle formed therein, and a suction or pick-up tube. These components are typically assembled to each other during assembly of an engine, and include interface joints between them that act to support and/or seal one to another. Assembly of multiple components adds to a cycle time in assembly of an engine, increases cost and complexity, and may present opportunity for leakage during the service life of an engine. Moreover, typical oil pan assemblies may be prone to failure of an attachment of the suction or pick-up tube to the upper oil pan. The conventional pick-up tube extends in a cantilever configuration from the upper oil pan. Vibratory and impulse loading on the pick-up tube during operation of the engine can lead to a premature failure of the connection between the pick-up tube and the upper oil pan.
An oil pan for an internal combustion engine includes a body that defines a reservoir cavity. A collector cavity is defined by at least one wall of the body and is in fluid communication with the reservoir cavity. An oil supply passage is defined by at least one wall of the body and is in fluid communication with the collector cavity.
An oil pan for an internal combustion engine includes a body defining a reservoir cavity, where the reservoir cavity has a shallow portion and a deep portion. A sealing interface surrounds the reservoir cavity along an edge of the body. An opening is formed in the sealing interface. A collector cavity is defined by the body and is in fluid communication with the deep portion of the reservoir cavity, and in fluid communication with the opening.
An internal combustion engine includes an engine crankcase with an oil pump operably connected to the crankcase. The engine also includes an oil pan for an internal combustion engine having a body that defines a reservoir cavity. A collector cavity is defined by at least one wall of the body and is in fluid communication with the reservoir cavity. An oil supply passage is defined by at least one wall of the body and is in fluid communication with the collector cavity.
The following describes an integrated oil pan for an internal combustion engine.
In one embodiment, the integrated oil pan is a single piece that incorporates the functions of a lower oil pan, an upper oil pan, and an oil pick-up or suction tube. The integrated oil pan may have superior resistance to leakage and failure, be less costly and easier to install when compared to traditional oil pan assemblies.
A prior art oil pan assembly 100 is shown in exploded view in
The upper pan 104 advantageously includes a plurality of openings 112 formed therein that are separated by a system of interconnected ribs 114. The openings 112 between the ribs 114 serve as drainage passages for oil dripping or being expelled from various engine components to enter the upper pan 104 and collect in an internal cavity 116 of the lower pan 102. The lower pan 102 may have a depressed region or sump 118 formed therein that is configured to be the lowest point of an oil circuit of the engine, and is also configured to accumulate oil that has been collected in the cavity 116 of the lower pan 102.
The pick-up tube assembly 106 may include a tube 120 that connects a mounting flange 122 to an upper bell housing 124. The mounting flange 122 is connected to the upper pan 104, and the upper bell housing 124 is connected to a lower bell housing 126 having a screen filter 128 located therebetween. The lower bell housing 126 has an opening 130 formed therein to allow for fluid communication of the tube 120 with the cavity 116 in the lower pan 102 when the oil pan assembly 100 is in an assembled state. During operation of the engine, an oil flow is pulled from the cavity 116 through the opening 130, is filtered by the screen 128, passes through the tube 120 and through the opening 110 in the upper oil pan 104 before reaching a component of the engine, for example, an inlet of an oil pump (not shown) on the engine.
During operation of the engine, aeration of the oil in the cavity 116 may occur because of splashing of oil from engine components, for example, counterweights on the crankshaft or components on the engine's valve train. Aeration of the oil in the cavity 116 can also occur due to mixing of the oil with air that occurs when the oil circulates through the engine. For these and other reasons, it is desirable to ingest oil into the engine through the pick-up tube 120 from a location that is as close as possible to the bottom of the lower pan 102. In turn, the tube 120 is advantageously extends to the bottom of the lower pan 102. One disadvantage of the tube 120 being long enough to extend to the bottom of the lower pan 102 is that it increases the cantilever effect of the connection between the pick-up tube 106 and the upper pan 104. To support the cantilever during vibration on the tube 120, some engines have a support strut 132 connecting the tube 120 and/or the upper bell housing 124 to the upper oil pan 104 or another engine component in the vicinity. While the support strut 132 is partially effective in increasing the rigidity of the connection between the pick-up tube 106 and the upper pan 104, it also introduces additional components and assembly complexity to the engine.
A top perspective view of an integrated oil pan 200 is shown in
A plurality of openings 214 are defined between a system of ribs 216 that connect opposing sides of the interface 208 and/or adjacent ribs. The openings 214 along with the ribs 216 form a baffle structure 218. In the oil pan 200, the baffle structure 218 is advantageously integral with the oil pan 200, eliminating the interface between a typical lower oil pan 102 (
The oil pan 200 is advantageously manufactured using a “lost foam” or “evaporative pattern casting process.” One example of such a casting process may be found in U.S. Pat. No. 4,633,929 by Santangelo et al., published on Jan. 6, 1987, the contents of which are incorporated herein in their entirety by reference. Alternatively, other manufacturing processes may be used to make the oil pan 200, for example, a lost wax molding process, a sand-casting process, an investment casting process, a die casting process of various pieces of the oil pan 200, fabrication of the oil pan 200 from two or more components that are connected to each other, and so forth.
Use of a lost foam casting process enables the formation of intricate shapes and passages in a cast metal component because there is no need for mold separation as exists in other casting methods. The oil pan 200 advantageously has an oil passage 220 formed therein to fluidly connect the opening 212 with the lower portion 206 of the reservoir cavity 202. A collector cavity 222 is formed near a distal end of the passage 220 that is opposite the opening 212 as is shown in a bottom perspective view of the oil pan 200 in
A cross-section of the oil pan 200 along a section 4-4 (shown in
A cross-section of the oil pan 200 along a section 5-5 (shown in
The oil pan 200 may advantageously be configured to mate directly to a crankcase of the engine, advantageously with enough assembly clearance for the bolts. Moreover, the pan 200 is designed to maximize a volume of the reservoir cavity 202, with the passage 220 having a simplified shape. It is contemplated that the passage 220 may protrude either within the reservoir cavity 202, or along an outside surface of the oil pan 200. Further, the groove 232 that retains the filter 226 is advantageously located in the collector cavity 222 along the bottom of the deep portion 206 of the oil pan 200. The collector cavity 222 should provide an adequate flow area around an inlet side of the filter 226 to reduce any flow restriction by the filter 226. The filter 226 is advantageously located near an elbow or turn 238 of the passage 220 to avoid or reduce cavitation in the flow of oil passing through the passage 220 during operation of the engine.
The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.
