Vehicle with parallel engine cooling systems

The technology disclosed herein relates to a grounds maintenance vehicle. The grounds maintenance vehicle has an engine and an engine shroud defining a cooling volume around the engine. The shroud defines a shroud intake. An engine oil conduit extends from the engine and a heat exchanger is coupled to the engine oil conduit.

TECHNOLOGICAL FIELD

Embodiments of the present disclosure are generally related to vehicles. More particularly, embodiments of the present disclosure are related to vehicles with parallel cooling systems.

BACKGROUND

Grounds maintenance vehicles such as lawn mowers, aerators, and spreader/sprayers are commonly used by homeowners and professionals alike. These vehicles are typically configured as walk-behind or ride-on vehicles having an attached implement (such as a grass cutting deck) to perform the maintenance work, where the implement is secured to a frame of the grounds maintenance vehicle. While different power sources are known, grounds maintenance vehicles utilizing an internal combustion (IC) engine to power the implement as well as a vehicle propulsion system are well known. IC engines are known to produce heat during operation and, as a result, various types of cooling systems can be employed to cool the engine. For example, grounds maintenance vehicles can simply utilize an air cooled engine where surrounding ambient air extracts heat from the engine.

In some examples, grounds maintenance vehicles may incorporate a liquid cooled engine, where liquid coolant circulating through the engine extracts heat. The heated coolant is then directed through a liquid-to-air heat exchanger (such as a radiator) where the heated coolant transfers heat to the surrounding ambient air environment. Air can be circulated around or through the heat exchanger to assist with heat transfer to the ambient air environment, such as through the use of a fan.

Debris is generally ubiquitous in the environments within which the grounds maintenance vehicles are used. Grass clippings, dirt, leaves, and the like, may be transported by airflow around the vehicle. As such, regardless of the specific type of cooling system employed, screens may be disposed around vehicle system components to obstruct such debris from adversely affecting vehicle systems.

SUMMARY

The technology disclosed herein relates to a vehicle having multiple engine cooling systems that operate in parallel. Some embodiments relate to a grounds maintenance vehicle. An engine enclosure defines an air intake area. A screen extends across the air intake area. The engine enclosure has at least one inner enclosure surface defining at least one airspace volume between the air intake area and the inner enclosure surface. An engine is disposed in the engine enclosure. An engine shroud defines an engine cooling volume about a portion of the engine. A heat exchanger is disposed in the engine enclosure. The heat exchanger is configured to receive engine oil. The vehicle defines a first airflow pathway extending from the air intake area to the engine shroud, and a second airflow pathway extending from the air intake area through the heat exchanger. The first airflow pathway and the second airflow pathway are arranged in parallel.

In some such embodiments, the grounds maintenance vehicle has a first fan disposed across the first airflow pathway. Additionally or alternatively, the grounds maintenance vehicle can have a second fan disposed across the second airflow pathway. Additionally or alternatively, the at least one airspace volume is a single airspace volume. Additionally or alternatively, the at least one airspace volume has a first airspace volume and a second airspace volume discrete from the first airspace volume. In such an embodiments the first airflow pathway extends through the first airspace volume and the second airflow pathway extends through the second airspace volume.

Additionally or alternatively, the engine shroud defines a shroud intake that extends to an airspace volume of the at least one airspace volume. Additionally or alternatively, a combustion intake extends from the engine shroud to an air cleaner. Additionally or alternatively, the inner enclosure surface forms a seal around each of the heat exchanger and the engine shroud. Additionally or alternatively, the screen defines an upper surface, a back surface and a front surface of the engine enclosure. Additionally or alternatively, the engine enclosure defines an engine cavity isolated from the at least one airspace volume, and the engine is disposed in the engine cavity.

Some embodiments of the technology disclosed herein relate to a grounds maintenance vehicle having an engine and an engine shroud defining a cooling volume around the engine. The engine shroud defines a shroud intake. An engine oil conduit extends from the engine. A heat exchanger is coupled to the engine oil conduit.

In some such embodiments the grounds maintenance vehicle has an engine enclosure containing the engine. The engine enclosure defines an air intake area, where at least one screen extends across the air intake area. The air intake area is upstream of the shroud intake and the heat exchanger. Additionally or alternatively, the screen defines an upper surface, a back surface and a front surface of the engine enclosure. Additionally or alternatively, the engine enclosure has at least one inner enclosure surface, where an airspace volume is defined between the screen and each inner enclosure surface, and where an airspace volume is upstream of each of the shroud intake and the heat exchanger.

Additionally or alternatively, the shroud intake extends to the airspace volume. Additionally or alternatively, the inner enclosure surface defines a first inner surface opening and the shroud intake extends across the opening. Additionally or alternatively, the inner enclosure surface defines a second inner surface opening and the heat exchanger extends across the opening. Additionally or alternatively, the vehicle has a combustion intake extending from the engine shroud to an air cleaner. Additionally or alternatively, the vehicle has a first fan configured to direct airflow into the engine shroud. Additionally or alternatively, the vehicle has a second fan configured to direct airflow into the heat exchanger.

In some embodiments, the present technology relates to grounds maintenance vehicle having a vehicle frame and drive wheels coupled to the vehicle frame. An implement is coupled to the vehicle frame and an engine enclosure is coupled to the vehicle frame. The engine enclosure defines an engine cavity and an airspace volume isolated from the engine cavity within the engine enclosure. The engine enclosure has a screened area between the airspace volume and an ambient environment. An engine is disposed in the engine cavity of the engine enclosure. A first engine cooling system has an engine shroud defining an engine cooling volume about a portion of the engine. The first engine cooling system defines a first airflow pathway extending from the screened area to the engine cavity via the engine cooling volume. A second engine cooling system has a heat exchanger, an oil flow pathway from the engine to the heat exchanger, and a second airflow pathway extending from the screened area to the engine cavity through the heat exchanger. A combustion intake extends from the shroud into the engine. In some such embodiments, the implement has a cutting deck.

The above summary is not intended to describe each embodiment or every implementation. Rather, a more complete understanding of illustrative embodiments will become apparent and appreciated by reference to the following Detailed Description of Exemplary Embodiments and claims in view of the accompanying drawings.

The figures are rendered primarily for clarity and, as a result, are not necessarily drawn to scale. Moreover, various structure/components, including but not limited to fasteners, electrical components (wiring, cables, etc.), and the like, may be shown diagrammatically or removed from some or all of the views to better illustrate aspects of the depicted embodiments, or where inclusion of such structure/components is not necessary to an understanding of the embodiments described herein. The lack of illustration/description of such structure/components in a particular figure is, however, not to be interpreted as limiting the scope of the various embodiments in any way.

DETAILED DESCRIPTION

In the following detailed description of illustrative embodiments, reference is made to the accompanying figures of the drawing which form a part hereof. It is to be understood that other embodiments, which may not be described and/or illustrated herein, are certainly contemplated.

All headings and subheadings provided herein are for the convenience of the reader and should not be used to limit the meaning of any text that follows the heading, unless so specified. Moreover, unless otherwise indicated, all numbers expressing quantities, and all terms expressing direction/orientation (e.g., vertical, horizontal, parallel, perpendicular, etc.) in the specification and claims are to be understood as being modified in all instances by the term “about.”

It is also noted that the term “comprises” (and variations thereof) does not have a limiting meaning where this term appears in the accompanying description and claims. Further, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably herein. Moreover, relative terms such as “left,” “right,” “front,” “fore,” “forward,” “rear,” “aft,” “rearward,” “top,” “bottom,” “side,” “upper,” “lower,” “above,” “below,” “horizontal,” “vertical,” and the like may be used herein and, if so, are from the perspective shown in the particular figure, or from the perspective of one operating the vehicle while it is in an operating configuration. The numerical descriptors such as “first,” “second,” and “third” are used herein to distinguish components having similar names and should not be interpreted as limiting the location or function of the particular component referenced. Each term is used only to simplify the description and is not meant to limit the interpretation of any embodiment described.

It should also be noted that, as used in this specification and the appended claims, the phrase “configured” describes a system, apparatus, or other structure that is constructed to perform a particular task or adopt a particular configuration. The word “configured” can be used interchangeably with similar words such as “arranged”, “adapted,” “constructed”, “manufactured”, and the like.

The suffixes “a” and “b” may be used with element numbers throughout this description to denote various right- and left-side parts/features, respectively. The parts/features denoted with “a” and “b” suffixes can be substantially identical to, or mirror images of, one another. It is understood that, unless otherwise noted, the description of an individual part/feature (e.g., part/feature identified with an “a” suffix) also applies to the opposing part/feature (e.g., part/feature identified with a “b” suffix). Similarly, the description of a part/feature identified with no suffix may apply, unless noted otherwise, to both the corresponding left and right part/feature and may correspond to a reference numeral on a drawing that is accompanied by a letter suffix.

With reference to the figures, where like reference numerals designate like parts and assemblies throughout the several views,FIG. 1illustrates an example grounds maintenance vehicle10in accordance with the present disclosure, which can simply be referred to as a “vehicle”.FIG. 2is another view of the vehicle10with an implement (e.g., cutting deck20) shown exploded from the vehicle10. The vehicle10, in the current example, is a wide area riding lawn mower. While embodiments are described herein with respect to such a mower, this disclosure is equally applicable to mowers having alternate configurations (e.g., walk-behind mowers and stand-on mowers). Moreover, embodiments of the present disclosure may also find application to other types of grounds maintenance vehicles (e.g., aerators, spreader-sprayers, dethatchers, debris management systems, blowers, vacuums, sweepers, general purpose utility vehicles, etc.) without limitation.

The vehicle10has a vehicle frame16. The vehicle10has a first portion that is an implement assembly20and a second portion that is a propulsion vehicle30. Each of the implement assembly20and the propulsion vehicle30are coupled to the vehicle frame16. The propulsion vehicle30of the grounds maintenance vehicle10can have drive wheels32(only left drive wheel32avisible inFIG. 1) and an internal combustion engine (not visible inFIGS. 1 and 2) that are configured to selectively propel the vehicle10across a ground surface. The propulsion vehicle30is configured to transmit engine power to the drive wheels32and to the implement assembly20. The engine can be contained within an engine enclosure40generally coupled to the vehicle frame16. The engine enclosure40(described in more detail herein) can be configured to partially isolate the engine from the ambient environment. The propulsion vehicle30can have handles36by which the vehicle10is directed and controlled by an operator. The propulsion vehicle30can also incorporate various other controls configured to be manipulated by the operator to control various functions of the vehicle10.

The currently-depicted implement assembly20is a mower deck assembly20that can be consistent with a walk-behind lawn mower, a ride-on lawn mower, or an autonomous mower as examples. The implement assembly20is configured to attach the vehicle frame16in what is commonly referred to as “mid-mounted” configuration. The implement assembly20is configured to perform a maintenance task on a surface, such as a ground or turf surface. In the current example, the implement assembly20is a mower deck assembly having a housing22defining a downwardly (as viewed inFIG. 1) opening cutting chamber (not visible). Cutting blades (not shown) are rotatably disposed within the cutting chamber. During operation, power is selectively delivered to the cutting blades by the engine, whereby the blades rotate at a speed sufficient to sever grass and other vegetation over which the deck passes. Other types of cutting decks (e.g., out-front decks, towed decks, reel units, etc.), as well as implements other than cutting decks, are contemplated within the scope of this disclosure.

The propulsion vehicle30of the grounds-maintenance vehicle can define components consistent with a ride-on lawn mower or a walk-behind lawn mower. In the current example, a seat14is coupled to a vehicle frame assembly12, where the seat is configured to support a seated operator. In some other embodiments, a standing platform is coupled to the vehicle frame, where the standing platform is configured to support a standing operator.

The vehicle frame assembly12may include the vehicle frame16having a first side15and a second side17. The vehicle frame16is coupled to a first ground-engaging member34aand a second ground-engaging member34bthat are disposed between the vehicle frame assembly12and the ground surface. The ground-engaging members34are generally configured to accommodate translation of the vehicle frame assembly12across the ground surface. In the current example, the ground engaging members34are wheels that are rotatably coupled to the vehicle frame assembly12. More particularly, the ground engaging members34are caster wheels that rotate (for rolling) and swivel (for turning) and are coupled to a front end11of the vehicle frame assembly12. In some embodiments, the ground engaging members can be alternate structures or components other than caster wheels such as tracks, rollers, or skids. While the members34are shown as passive (undriven wheels), in other embodiments they may be drive wheels.

The implement assembly20has a first (e.g., front) implement end21and a second (e.g., rear) implement end23and is generally configured for operational interaction with the ground surface. In the current example, the implement assembly20is configured to be disposed between at least a portion of the vehicle frame assembly12and the ground surface (e.g., a mid-mounted deck). In the current example, the implement assembly20also has a plurality of ground-engaging members configured to enable translation of the implement assembly20across the ground. For example, a plurality of caster wheels26may be coupled to the implement assembly20. The implement assembly20can also have a plurality of rollers24(e.g., anti-scalp rollers) configured to be disposed between the implement assembly20and a ground surface to limit contact between parts of the implement assembly20(e.g., the cutting blades) and the ground surface. The plurality of rollers24can be configured to reduce scalping of the ground surface as the implement assembly translates across the ground surface.

The implement assembly20can be coupled to the vehicle frame assembly12through a variety of types of coupling structures such as chains, rods, linkages, cables, slotted plates, and other structures that allow the implement assembly20to hang from the vehicle frame assembly12. Such coupling structures can define an operating height or “height-of-cut” of the implement assembly20relative to the ground surface. In various embodiments, the operating height between the implement assembly20and the ground surface is selectable by a user.

FIG. 3Ais a first perspective, isolated view of an example engine enclosure40consistent with various embodiments, where a screen46(seeFIG. 4) is shown as transparent in this view for clarity.FIG. 3Bis a second perspective, isolated view of the example engine enclosure40consistent with various embodiments.FIG. 4is a cross-sectional view of the example engine enclosure40taken along line4-4ofFIG. 3A. The engine enclosure40is coupled to the vehicle frame16(seeFIG. 1) and is generally configured to partially or completely contain or surround the vehicle engine and its associated engine cooling systems as further described herein. In various embodiments, the engine enclosure40is configured to contain an air-cooled engine with a separate engine oil cooler.

The engine enclosure40generally defines an air intake area41that is configured to permit passage of outside ambient air into the engine enclosure40. The air intake area41is in fluid communication with each of the plurality of air cooling systems.

The engine enclosure40has an outer enclosure assembly45forming an outer surface of the engine enclosure40, and an inner enclosure surface48. The outer enclosure assembly45defines an air intake area41. the outer enclosure assembly45has a screen46that extends across the air intake area41. InFIGS. 3A and 3B, the screen46is shown to be transparent for visibility of components within the engine enclosure40. The screen46is generally configured to accommodate airflow through the opening41. The screen46is also configured to obstruct air-entrained debris from passing into the engine enclosure40. The screen46can be constructed of a metallic or plastic mesh in some embodiments. Other materials can also be used.

The screen46can define various outer surfaces of the engine enclosure40. In the current example, the screen46defines an upper surface50, a front surface52(seeFIG. 3B), and a back surface54of the engine enclosure40. In some embodiments the screen can define additional surfaces of the engine enclosure40, such as a first side surface56and a second side surface58. In some embodiments the screen can define only the upper surface50and back surface54of the engine enclosure40.

While the air intake area41is currently depicted as a single, unified opening (albeit covered with the screen46), in some other embodiments the air intake area41can be defined by multiple openings in the outer enclosure assembly45. In such embodiments a screen would be coupled to the outer enclosure assembly about each of the multiple opening that define a portion of the air intake area.

The inner enclosure surface48generally defines an airspace volume49between the inner enclosure surface48and the screen46of the engine enclosure40. The airspace volume49is configured to receive ambient air from the air intake area41. The inner enclosure surface48defines a first inner surface opening60and a second inner surface opening62to accommodate airflow there-through. The first inner surface opening60is a portion of a first airflow pathway70and the second inner surface opening62is a portion of a second airflow pathway72. Each of the first airflow pathway70and the second airflow pathway72extend from the ambient environment external to the engine enclosure40, through the screen46and into the airspace volume49. In some embodiments, however, there can be multiple, discrete airspace volumes defined by the inner enclosure surface48and the screen46. In such embodiments, the first airflow pathway70can extend through a first airspace volume and the second airflow pathway72can extend through a second airspace volume. In general, the first airflow pathway70and the second airflow pathway72are parallel flow paths. In some embodiments the first airflow pathway70and the second airflow pathway72are in fluid communication in the airspace volume49.

In the current example, the engine enclosure40is formed by a hood42and a lower structure44(e.g., casting44). The hood42has an outer hood surface51that defines a portion of the outer enclosure assembly45. The outer hood surface51defines an outer hood opening41that is the air intake area41. As such, the screen46is coupled to the outer hood surface51across the outer hood opening41. In this example, the outer enclosure assembly45is defined by the outer hood surface51, the screen46, and the casting44. The hood42also has an inner hood surface48that is the inner enclosure surface48of the engine enclosure40.

The hood42can be removably coupled to the lower casting44such that an operator can access system components therein. In the current example a hinge47couples the hood42to the lower casting44. An operator can pivot the hood42about the hinge47relative to the lower casting44to access the engine and other components contained within the engine enclosure40. The engine enclosure40can have alternate configurations. In some embodiments the lower casting and the hood are a single cohesive component. In some embodiments the casting defines portions of the inner enclosure surface. In some embodiments the casting defines one or more openings that are a portion of the air intake area.

Vehicles consistent with embodiments of the present application can have a first engine cooling system2and a second engine cooling system4(seeFIG. 4). The first engine cooling system2and the second engine cooling system4may operate in parallel. The first airflow pathway70can be part of the first engine cooling system2and the second airflow pathway72can be part of the second engine cooling system4. The first engine cooling system2can be configured to air cool the engine and ancillary components. The second engine cooling system4can be configured to air cool engine oil.

The engine80is disposed within the engine enclosure40. Particularly, the engine80is contained in an engine cavity43of the engine enclosure40, which is defined between the inner enclosure surface48and the lower structure44(e.g., the casting) of the engine enclosure40. The engine cavity43can be generally isolated from the airspace volume49within the engine enclosure40. The first engine cooling system2has an engine shroud90having a main portion91that covers at least a portion of the engine80. In various embodiments, the engine shroud90is configured to receive an engine head of the engine80. The engine shroud90defines an engine cooling volume92around a portion of the engine80. The engine shroud90can define the engine cooling volume92particularly around the engine head. The engine shroud90is generally configured to direct airflow in a generally downward direction to wash over and cool the engine and ancillary components. The engine shroud90can be constructed of a variety of materials and combinations of materials, but will generally be constructed of a substantially impermeable material to relatively increase airflow over the engine80. In some embodiments the engine shroud90is constructed of metal or plastic.

The engine shroud90has a shroud intake94and a shroud outlet93. The shroud outlet93is an opening defined by the engine shroud90in the engine cavity43of the engine enclosure40. The shroud outlet93can be positioned vertically below the engine head86. The shroud outlet93can be defined around a portion of the engine80in a variety of embodiments. The shroud outlet93defines a portion of the first airflow pathway70that is downstream of the main portion91of the engine shroud90. From the shroud outlet93, air in the first airflow pathway70can exit to the ambient environment through exhaust vent openings74defined in the outer enclosure between the engine cavity43and ambient environment (seeFIGS. 3A, 3B, and 4). In some embodiments, air in the first airflow pathway70can exit to the ambient environment through exhaust vent opening(s)74in the lower structure44(e.g., the casting, particularly visible inFIG. 3B). In some embodiments, there are one or more exhaust vent openings74in a front portion of the lower structure44(seeFIG. 3B). In some embodiments, air in the first airflow pathway70can exit to the ambient environment through exhaust vent openings74(visible inFIGS. 3A and 3B) defined by the engine enclosure40. It is noted that a screen can be coupled to the engine enclosure40about one or more exhaust vent openings to prevent the ingress of debris to the engine cavity43.

The shroud intake94of the shroud90is configured to receive air from the airspace volume49and direct the received air to the shroud. In the current example, the shroud90has a tubular projection96that defines the shroud intake94. The tubular projection96extends between the engine cooling volume92and the airspace volume49. The tubular projection96is disposed about the first inner surface opening60of the inner enclosure surface48. In some embodiments, the shroud intake94may extend up to the airspace volume49. The tubular projection96is configured to direct air from the airspace volume49into the engine cooling volume92of the shroud90. The inner enclosure surface48can form a seal around the shroud intake94. In particular, the inner enclosure surface48can form a seal with the engine shroud90about the shroud intake94. In the current example, the inner enclosure surface48forms an axial seal with an annular surface95of the tubular projection96about the shroud intake94. In some other embodiments the inner enclosure surface48can form a radial seal with the tubular projection96about the shroud intake94. In the current example, the tubular projection96extends from the main portion91of the engine shroud90upwardly to the airspace volume49.

The tubular projection96can be constructed of a variety of different materials and combinations of materials. In some embodiments, the tubular projection96is constructed of foam. In some embodiments the tubular projection96forms a unitary, cohesive structure with a main portion91of the shroud (i.e., the portion of the engine shroud90defining the engine cooling volume236that surrounds the engine80). In some embodiments, the tubular projection96is a unitary, cohesive structure with the inner enclosure surface48. In the current embodiment, however, the tubular projection96is a separate component from both the shroud90and the inner enclosure surface48. Here the tubular projection96is coupled to a main portion91of the engine shroud90and the inner enclosure surface48.

A first fan82is disposed in the first airflow pathway70to generate airflow along the first airflow pathway from the airspace volume49to the engine cooling volume92. As such, the screen46and the airspace volume49are positioned upstream of the shroud intake94along the first airflow pathway70. In the current example, the first fan82is disposed in or above the engine shroud90. In examples, the first fan82can be an engine flywheel fan. The mass flow rate of air within the first airflow pathway70is generally regulated by the first fan82. In some examples, the mass flow rate of the first fan82can range from 1,000 cubic feet/minute (ft3/min) to 1,400 ft3/min. In the current example, there is an engine stationary guard87and a rotating screen located next to a stationary chopping blade to reduce the debris size before it enters the engine cooling volume92.

The tubular projection96defines a shroud intake area Ashroud. In various embodiments, the shroud intake area Ashroudis less than the area of a first portion41aof the air intake area41defining the first airflow pathway70. The first portion41aare the regions of the air intake area41where airflow tends to be directed to the shroud90. As a result, the velocity of air passing through the shroud intake94is greater than the velocity of the air passing through the first portion41aof the air intake area41. In some examples, the ratio of the first portion41aof the air intake area41to the shroud intake area Ashroudis at least 10 to 1. The ratio of the first portion of the air intake area41ato the shroud intake area Ashroudcan be at least 15 to 1, or 17 to 1.

The air intake area41can be sized to limit the velocity of ambient airflow therethrough, thereby limiting the amount of debris that would be carried to the screen46by the airflow. In an example, the air intake area41has an area of from about 700 square inches (in2) to about 1300 in2. In one particular example the air intake area41has an area from 800 in2to 1000 in2. Other exemplary factors that can dictate the velocity of the air through a particular portion of the air intake area41can include the distance between the shroud intake94and the air intake area41and the configuration of the inner enclosure surface adjacent the air intake area41.

In some embodiments, the engine80receives combustion air from the first airflow pathway70.FIG. 5depicts a perspective view of the engine80and engine shroud90consistent with various embodiments. The engine80has an air intake (e.g., air cleaner84) that is generally configured to receive air. A combustion intake98directs air from the shroud intake94to the air cleaner84. The combustion intake98has an air box97and a tube extension99, where the tube extension99extends from the tubular projection96to the air box97. The air box97is thus in fluid communication with the air cleaner84as well as the first airflow pathway70. As a result of configurations consistent with the present example, the engine80is configured to receive air that has already passed through the screen46(seeFIG. 4), thus minimizing the presence of entrained debris therein.

The first airflow pathway70discussed herein is generally defined by the first engine cooling system2of a vehicle. In various embodiments, the vehicle may also define a second engine cooling system4that operates in parallel to the first engine cooling system2. Returning toFIGS. 3A and 4, an exemplary second engine cooling system4will now be described. The second engine cooling system4has a liquid-to-air heat exchanger100. The heat exchanger100is generally configured to reduce the temperature of engine oil from the engine80. In particular, the heat exchanger100receives engine oil from the engine80and ambient air is directed through the heat exchanger100to extract heat from the heat exchanger100and, therefore, the engine oil. Cooled oil is then returned to the engine.

The heat exchanger100is disposed in the engine enclosure40, which in the illustrated embodiments, is thus operatively coupled to the vehicle frame16(seeFIG. 2, for example). In particular, the heat exchanger100is coupled to the inner enclosure surface48about the second inner surface opening62. The heat exchanger100can extend partially or completely across the second inner surface opening62and second airflow pathway72. In some embodiments, the inner enclosure surface48forms a seal around the heat exchanger100. As such, the second airflow pathway72extends from the ambient environment, through the screen46, into the airspace volume49, through the heat exchanger100, and into the engine cavity43of the engine enclosure40. The second airflow pathway72extends out to the ambient environment from the engine cavity43through the exhaust vent openings74(visible inFIGS. 3A, 3B, and 4) of the engine enclosure40, which can include openings at the bottom of the engine enclosure. As such, the first airflow pathway70and the second airflow pathway72merge in the engine cavity43. Both the first airflow pathway70and the second airflow pathway72extend through the engine cavity43and the exhaust vent openings74(FIGS. 3A, 3B, and 4).

A second fan102(visible inFIG. 4) is disposed in the engine enclosure40. The second fan102is configured to generate airflow along the second airflow pathway72from the airspace volume49through the heat exchanger100. The screen46and the airspace volume49are positioned upstream of the heat exchanger100along the second airflow pathway72. The second fan102can be coupled to the heat exchanger100and across the second airflow pathway72. The mass flow rate of air within the second airflow pathway72is generally regulated by the second fan102.

The heat exchanger100defines an intake area Aexchanger. In various embodiments, the sum of the heat exchanger intake area Aexchangerand the shroud intake area Ashroud(discussed above) is less than the air intake area41. As a general result of such a configuration, the velocity of air passing through the air intake area41is lower than the velocity of the air passing through the heat exchanger100.

The heat exchanger intake area Aexchangeris generally less than the area of a second portion41bof the air intake area41defining the second airflow pathway72. The second portion41bis the region(s) of the air intake area41where airflow tends to be directed through the heat exchanger100. As a result, the velocity of air passing through the heat exchanger100is greater than the velocity of the air passing through the second portion41bof the air intake area41. In some examples, the ratio of the second portion41bof the air intake area41to the heat exchanger intake area Aexchangeris at least 3 to 2. The ratio of the second portion41bof the air intake area41to the heat exchanger intake area Aexchangercan be at least 2 to 1 or 3 to 1

FIG. 6depicts a perspective view of the engine80and the second engine cooling system4consistent with various embodiments. An engine oil conduit104generally extends from the engine80to an oil inlet108of the heat exchanger100. The heat exchanger100further defines an oil outlet110. A return line112extends from the oil outlet110to the engine80and is configured to return cooled oil to the engine80from the heat exchanger100.

A pump (not shown) is generally in fluid communication with the engine oil conduit104and the return line112. The pump is configured to cycle the engine oil through the heat exchanger100. In some embodiments, the engine80is a pressure lubricated engine, where the engine incorporates a lubricant pump that is configured to cycle engine oil through an oil flow pathway including an oil filter and engine components targeted for lubrication. In some such embodiments the heat exchanger100, the engine oil conduit104and the return line112can be components along such an oil flow pathway. In such an example, a separate pump may advantageously be avoided because the lubricant pump can be used for the lubrication system and the second engine cooling system. In some other embodiments, a separate pump can be used to cycle engine oil through the heat exchanger100.

WhileFIGS. 1-6depict examples consistent with a particular example vehicle, other configurations are certainly possible.FIG. 7depicts a schematic view of an example vehicle200with parallel cooling systems consistent with various embodiments. The example vehicle200can be consistent with an autonomous mower, as an example, or another type of vehicle. Components referenced herein can generally be consistent with the descriptions of similarly-named components described above with reference toFIGS. 1-6. The vehicle200has an engine enclosure210, an engine220disposed in the engine enclosure210, a first engine cooling system230, and a second engine cooling system240.

The engine enclosure210has an outer enclosure assembly212having a screened area defined by a screen211and an outer enclosure surface213. The engine enclosure210has an inner enclosure surface214. The screen211and the inner enclosure surface214define an airspace volume216. The screen211defines an air intake area that leads to the airspace volume216. The engine enclosure210and the inner enclosure surface214define an engine cavity218that receives the engine220.

The first engine cooling system230is configured to air cool the engine220. The first engine cooling system230has a shroud234that defines an engine cooling volume236about a portion of the engine220. The first engine cooling system230defines a first airflow pathway232through the engine enclosure210. The first airflow pathway232extends from the ambient environment through the screen211, into the airspace volume216to the engine cooling volume236within the shroud234. The first airflow pathway232extends from the shroud234through a shroud outlet237into the engine cavity218and out a vent opening(s)219and other openings defined by the engine enclosure210. The vent opening(s)219can also be defined by a screen forming a portion of the outer enclosure assembly212. A first fan238can be disposed across the first airflow pathway232to generate the airflow along the first airflow pathway232. In the current example, the first fan238is depicted upstream of the shroud234, but the first fan238can also be positioned elsewhere, such as within the shroud234as depicted in examples discussed above.

In a variety of embodiments, a combustion intake222is in fluid communication with the first airflow pathway232to receive air from the first airflow pathway232. The combustion intake222extends to the engine220(such as an air cleaner of an engine) for combustion. In some embodiments the combustion intake222is coupled to the shroud234, but in other embodiments the combustion intake222is not coupled to the shroud234. The combustion intake222can extend into the first airflow pathway232. In various examples, including the one currently depicted, the combustion intake222is in fluid communication the first engine cooling system230. In other embodiments the combustion intake222is not in fluid communication with the first engine cooling system230.

The second engine cooling system240is configured to cool engine oil. The second engine cooling system240defines an oil flow pathway250and a second airflow pathway242. The second engine cooling system240has a heat exchanger252disposed in the engine enclosure210, where the heat exchanger252is a component along the oil flow pathway250and is configured to receive engine oil. The second airflow pathway242extends from the ambient environment through the screen211, into the airspace volume216to the heat exchanger252. The second airflow pathway242extends through the heat exchanger252into the engine cavity218and out the vent opening(s)219defined by the engine enclosure210. A second fan244can be disposed across the second airflow pathway242to generate the airflow along the second airflow pathway242. Here the second fan244is depicted upstream of the heat exchanger252, but the second fan can also be positioned downstream of the heat exchanger, as depicted in examples discussed above.

In various embodiments, the second engine cooling system240has a pump254disposed along the oil flow pathway250that is configured to cycle engine oil between the heat exchanger252and the engine220. As discussed above, the pump254can be a component of the engine220, or the pump254may be separate from the engine220. In various embodiments, a filter256may be in fluid communication with the oil flow pathway250to filter the engine oil. In some other embodiments, a filter is not along the oil flow pathway250.

It is noted that, in the example ofFIG. 7, the airspace volume216is a single airspace volume common to both the first airflow pathway232and the second airflow pathway242. As such, the first airflow pathway232and the second airflow pathway242are connected at the airspace volume216. However, the first airflow pathway232and the second airflow pathway242diverge downstream of the airspace volume216. The first airflow pathway232and the second airflow pathway242merge in the engine cavity218and through the vent opening(s)219.

FIG. 8is another schematic of an example vehicle300showing some variations of the example ofFIG. 7. The example vehicle300can be consistent with an autonomous mower, as an example, or another type of vehicle. In the current schematic, a screened area311defines an air intake area (also denoted by311). In particular the screened area311has two discrete screens: a first screen313and a second screen315. The first screen313defines a first air intake area (also denoted by313). The second screen315defines a second air intake area (also denoted by315). The first screen313and a first inner enclosure surface314define a first airspace volume316. The second screen315and a second inner enclosure surface318define a second airspace volume317discrete from the first airspace volume316. As such, a first airflow pathway332extends from the first airspace volume316and a second airflow pathway344extends from the second airspace volume317. The first airspace volume316and the second airspace volume317can cumulatively be referred to as the airspace volume of the example vehicle, however. Similarly, the first intake area313and the second air intake area315may cumulatively be referred to as the air intake area of the vehicle300. It is also noted that, in the current example, an oil flow pathway350extends from the engine320and has a heat exchanger352and a pump354, but lacks a filter, such as that described above with reference toFIG. 7.

This application is intended to cover adaptations or variations of the present subject matter. It is to be understood that the above description is intended to be illustrative, and not restrictive, and the claims are not limited to the illustrative embodiments as set forth herein.