IP Library Granted Patent US 12,416,252
Granted Patent B2
US 12,416,252 · App. 17/712,285 · Granted Sep 16, 2025

Small air-cooled engine assembly with dry sump lubrication system

Inventors: Adam J. Hellman (Bayside, WI); John Schneiker (Muskego, WI); Tim Kwiatkowski (Muskego, WI); Casey Groh (Shorewood, WI); Robert Price (Wauwatosa, WI); Ryan Sullivan (West Bend, WI); Gary Johnson (Hales Corners, WI)
Assignee: Briggs & Stratton, LLC
F01N1/10A01D69/00F01M1/12F01M11/00F01M11/0004F01M11/03F01M11/12F02B75/007F02F7/0039F02F7/0068F16N19/00A01D2101/00F01M2001/1007F01M2001/1071F01M2001/1078F01M2001/1092F01M2001/123F01M2001/126F01M2011/0029F01M2011/0083F01M2011/0095F01M2011/038F01M2011/0491
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Quick Facts
Patent No.
US 12,416,252
App. No.
17/712,285
Granted
Sep 16, 2025
Kind
B2
Abstract

An engine assembly includes a small air-cooled engine and a dry sump lubrication system including an external oil reservoir, wherein the dry sump lubrication system has an overall oil capacity that provides at least five hundred hours of engine oil life.

Claims (69)

1. A lawn mower, comprising:

an air-cooled engine having two or fewer cylinders;

a seat;

a dry sump lubrication system including an external engine oil reservoir configured to supply oil to the air-cooled engine; and

a roll bar extending above a height defined by the seat and including a first vertical leg defining a first inner surface and a second vertical leg defining a second inner surface, wherein the external oil reservoir is positioned laterally between a first plane that is parallel to and intersects the first inner surface and a second plane that is parallel to and intersects the second inner surface.

2. The lawn mower of claim 1 , wherein the external oil reservoir has an oil fill capacity of at least five quarts.

3. The lawn mower of claim 2 , wherein the dry sump lubrication system includes a crankcase chamber; wherein an intended oil fill level of the crankcase chamber is between 2.5 quarts to 3 quarts.

4. The lawn mower of claim 1 , wherein the air-cooled engine includes a crankshaft including a counterweight positioned in a crankcase chamber; and

wherein a recommended oil level of the crankcase chamber during normal operation of the engine is below a lowermost portion of the counterweight.

5. The lawn mower of claim 4 , wherein an intended oil fill level of the crankcase chamber is between 2.5 quarts to 3 quarts.

6. The lawn mower of claim 1 , wherein the air-cooled engine comprises:

an engine block;

an oil gallery configured to distribute oil;

a crankcase cover; and

a crankcase chamber defined by the engine block and the crankcase cover; and

wherein the dry sump lubrication system comprises:

the external oil reservoir comprising:

an oil tank defining an oil chamber; and

an oil filter assembly comprising:

a housing at least partially defining a filter chamber, wherein the filter chamber is in fluid communication with the oil chamber; and

a filter positioned within the filter chamber;

a supply pump in fluid communication with the oil chamber and the oil gallery, wherein the supply pump is configured to draw oil from the oil chamber and provide pressurized oil to the oil gallery; and

a return pump in fluid communication with the crankcase chamber and the filter chamber, wherein the return pump is configured to draw oil from the crankcase chamber and provide pressurized oil to the filter chamber;

wherein the filter is configured to filter the pressurized oil provided to the filter chamber.

7. The lawn mower of claim 6 , wherein the crankcase chamber has a crankcase volume and the oil chamber has a reservoir volume greater than the crankcase volume.

8. The lawn mower of claim 7 , wherein the reservoir volume is at least five quarts.

9. The lawn mower of claim 6 , further comprising:

a crankshaft including a counterweight positioned in the crankcase chamber;

wherein a recommended oil level of the crankcase chamber during normal operation of the engine is below a lowermost portion of the counterweight.

10. The lawn mower of claim 6 , wherein the oil filter assembly includes a fill inlet so that oil can be added to the oil chamber through the oil filter.

11. The lawn mower of claim 6 , wherein the filter comprises filter media and an oil fill conduit extending through the filter media so that oil can be added to the oil chamber through the oil fill conduit without being filtered by the filter media.

12. The lawn mower of claim 6 , wherein the oil filter assembly further comprises:

a vent assembly in fluid communication with the oil chamber, the filter chamber, and the internal combustion engine, wherein the vent assembly is configured to allow air to flow from the filter chamber and the oil chamber to the internal combustion engine.

13. The lawn mower of claim 6 , further comprising;

a second oil filter assembly comprising:

a second housing at least partially defining a second filter chamber, wherein the second filter chamber is fluidly coupled to the supply pump and the oil gallery; and

a second filter positioned within the second filter chamber;

wherein the second filter is configured to filter the pressurized oil provided to the oil gallery.

14. The lawn mower of claim 1 , wherein the air-cooled engine comprises:

an engine block;

an oil gallery configured to distribute oil;

a crankcase cover; and

a crankcase chamber defined by the engine block and the crankcase cover; and

wherein the dry sump lubrication system comprises:

the external oil reservoir comprising:

an oil tank defining an oil chamber; and

an oil filter assembly comprising:

a housing at least partially defining a filter chamber; and

a filter positioned within the filter chamber;

a supply pump in fluid communication with the oil chamber and is configured to provide pressurized oil to the oil gallery; and

a return pump in fluid communication with the crankcase chamber and the filter chamber, wherein the return pump is configured to draw oil from the crankcase chamber and provide pressurized oil to the filter chamber;

wherein the filter chamber is fluidly coupled to the supply pump and the oil gallery; and

wherein the filter is configured to filter the pressurized oil provided to the oil gallery.

15. The lawn mower of claim 1 , wherein the air-cooled engine comprises:

an engine block;

a blower housing extending over a portion of the engine block and configured to direct cooling air over the engine block; and

a blower fan configured to pull air into the blower housing through an air inlet.

16. The lawn mower of claim 15 , wherein the two or fewer cylinders include a first cylinder arranged within a first cylinder head and a second cylinder arranged within a second cylinder head, and wherein a portion of the external oil reservoir is arranged between a rear plane defined along a rear of the air-cooled engine and the first cylinder head.

17. A lawn mower, comprising:

an air-cooled engine having two or fewer cylinders and defining a crankshaft axis;

a seat;

a dry sump lubrication system including an external oil reservoir, wherein the external oil reservoir is positioned between the crankshaft axis and the seat; and

a roll bar extending above a height defined by the seat, and including a first vertical leg and a second vertical leg, wherein the external oil reservoir is positioned between the first vertical leg and the second vertical leg, and wherein the air-cooled engine and the external oil reservoir are positioned rearward of the seat.

18. The lawn mower of claim 17 , wherein the air-cooled engine comprises:

an engine block;

a blower housing extending over a portion of the engine block and configured to direct cooling air over the engine block; and

a blower fan configured to pull air into the blower housing through an air inlet.

19. The lawn mower of claim 1 , wherein the external oil reservoir is dimensioned by a first distance and a second distance greater than the first distance, wherein the first distance extends in a longitudinal direction between the air-cooled engine and the seat, and the second distance extends in a lateral direction between the first vertical leg and the second vertical leg of the roll bar.

20. The lawn mower of claim 17 , wherein the external oil reservoir is dimensioned by a first distance and a second distance greater than the first distance, wherein the first distance extends in a longitudinal direction between the air-cooled engine and the seat, and the second distance extends in a lateral direction between the first vertical leg and the second vertical leg of the roll bar.

Continuity (5)
Continuation 15775704
Continuation 15295294 · Oct 17, 2016
Provisional Application 62335500 · May 12, 2016
Provisional Application 62255227 · Nov 13, 2015
Related Publication 20220228517A1 · Jul 21, 2022
References Cited (99)
US 2106218A · Kriek · 1938 [cited by applicant]
US 2134161A · Watson · 1938 [cited by examiner]
US 2322463A · McDonald · 1943 [cited by applicant]
US 2621796A · Wilkinson · 1952 [cited by applicant]
US D181664S · Muller · 1957 [cited by applicant]
US 3183899A · Tuggle · 1965 [cited by examiner]
US 3417562A · Morris · 1968 [cited by examiner]
US 3950251A · Hiller · 1976 [cited by applicant]
US 4151823A · Grosse · 1979 [cited by examiner]
US 4353163A · Overbury · 1982 [cited by examiner]
US 4560477A · Moldow · 1985 [cited by applicant]
US 4681189A · Krisiloff · 1987 [cited by applicant]
US 4724806A · Hartwig · 1988 [cited by applicant]
US RE32620E · Iwai · 1988 [cited by applicant]
US 4750456A · Ladrach · 1988 [cited by applicant]
US 4903654A · Sato · 1990 [cited by examiner]
US D317040S · Petrucci et al. · 1991 [cited by applicant]
US 5031591A · Shinoda et al. · 1991 [cited by applicant]
US 5035797A · Janik · 1991 [cited by applicant]
US 5112476A · Cote et al. · 1992 [cited by applicant]
US 5458101A · Crooks · 1995 [cited by applicant]
US 5568842A · Otani · 1996 [cited by applicant]
US 5634832A · Nakase et al. · 1997 [cited by applicant]
US 5753071A · Spencer · 1998 [cited by applicant]
US 5755194A · Moorman et al. · 1998 [cited by applicant]
US D403740S · Kott et al. · 1999 [cited by applicant]
US 5865020A · Busboom · 1999 [cited by examiner]
US 5950579A · Ott · 1999 [cited by examiner]
US 5979392A · Moorman et al. · 1999 [cited by applicant]
US 6032635A · Moorman et al. · 2000 [cited by applicant]
US 6048455A · Janik · 2000 [cited by applicant]
US 6167990B1 · Peng · 2001 [cited by applicant]
US 6230680B1 · Pirone · 2001 [cited by applicant]
US 6305342B1 · Narita et al. · 2001 [cited by applicant]
US D455194S · Kurth et al. · 2002 [cited by applicant]
US 6442917B1 · Velke · 2002 [cited by examiner]
US 6459995B1 · Collister · 2002 [cited by applicant]
US D466969S · Druga · 2002 [cited by applicant]
US 6524149B1 · Hattori · 2003 [cited by applicant]
US 6679692B1 · Fueling · 2004 [cited by applicant]
US 6874593B2 · Abend et al. · 2005 [cited by applicant]
US 7017546B1 · Patel et al. · 2006 [cited by applicant]
US D521137S · Khalil · 2006 [cited by applicant]
US 7162991B2 · White et al. · 2007 [cited by applicant]
US 7174876B2 · Suzuki et al. · 2007 [cited by applicant]
US 7185729B2 · Moriyama · 2007 [cited by applicant]
US 7188601B1 · Trease · 2007 [cited by applicant]
US 7219645B2 · Lamb et al. · 2007 [cited by applicant]
US 7290995B2 · Ohnishi et al. · 2007 [cited by applicant]
US 7648565B2 · Jiang · 2010 [cited by applicant]
US D626204S · Morgan · 2010 [cited by applicant]
US 7967981B2 · Talamali · 2011 [cited by applicant]
US D646750S · Salvador et al. · 2011 [cited by applicant]
US D647594S · Bridges et al. · 2011 [cited by applicant]
US 8028672B2 · Prior et al. · 2011 [cited by applicant]
US D648565S · Frinier · 2011 [cited by applicant]
US D648822S · Salvador et al. · 2011 [cited by applicant]
US 8230835B2 · Gibson et al. · 2012 [cited by applicant]
US D717912S · Huda et al. · 2014 [cited by applicant]
US 8910610B2 · Thayer · 2014 [cited by applicant]
US 9333448B2 · Braunheim et al. · 2016 [cited by applicant]
US 9469551B2 · Sherman et al. · 2016 [cited by applicant]
US 9567616B2 · Ujihara et al. · 2017 [cited by applicant]
US D782000S · Morris et al. · 2017 [cited by applicant]
US 9597616B2 · Blunt et al. · 2017 [cited by applicant]
US 9624797B2 · Bonde et al. · 2017 [cited by applicant]
US 9988955B1 · Suwa et al. · 2018 [cited by applicant]
US D825029S · Goldman · 2018 [cited by applicant]
US D854650S · Hellman et al. · 2019 [cited by applicant]
US D855755S · Coelho et al. · 2019 [cited by applicant]
US D882038S · Loepfe · 2020 [cited by applicant]
US 10612258B2 · Coelho et al. · 2020 [cited by applicant]
US 20010015182A1 · Moorman et al. · 2001 [cited by applicant]
US 20060096809A1 · Evans · 2006 [cited by applicant]
US 20070181481A1 · Reynolds et al. · 2007 [cited by applicant]
US 20080115488A1 · Iida et al. · 2008 [cited by applicant]
US 20080179139A1 · Montgomery · 2008 [cited by applicant]
US 20090173580A1 · Papas · 2009 [cited by applicant]
US 20130048088A1 · Miller · 2013 [cited by applicant]
US 20150053505A1 · Klowak · 2015 [cited by examiner]
US 20170138232A1 · Hellman et al. · 2017 [cited by applicant]
US 20180334934A1 · Hellman et al. · 2018 [cited by applicant]
CN D304666145 · 2018 [cited by applicant]
DE 102006017924A1 · 2007 [cited by applicant]
EP 0638708A1 · 1995 [cited by applicant]
EP 0752518A1 · 1997 [cited by applicant]
EP 1199447A1 · 2002 [cited by applicant]
EP 1201883A2 · 2002 [cited by applicant]
EP D000113260004 · 2003 [cited by applicant]
JP 62165016A · 1987 [cited by applicant]
JP 2008115727A · 2008 [cited by applicant]
KR D300837385000 · 2016 [cited by applicant]
WO WO9520099A1 · 1995 [cited by applicant]
WO WO2017083101A1 · 2017 [cited by applicant]
https://www.aaa.com/autorepair/articles/how-often-should-you-change-engine-oil (Year: 2001). [cited by examiner]
https://www .aaa.com/autorepair/articles/how-often-should-you-change-engine-oil. pdf (Year: 2021). [cited by applicant]
International Search Report and Written Opinion, PCT/US2016/058909, Briggs & Stratton Corporation, 12 pages (Jan. 31, 2017). [cited by applicant]
Mann-Filter, announced Oct. 10, 2007[online], [site visited Dec. 30, 2020]. Available from internet, URL :<https://www.amazon.com/Mann-Filter-WK-853-Fuel-Filter/dp/B000CB9558> (Year: 2007). [cited by applicant]
PG Oil Filter, announced May 14, 2018[online], [site visited Dec. 30, 2002]. Available from internet, URL :<https://www.amazon.com/Premium-Guard-PG99139-2016-2018-Chevrolet/dp/B07D2GQ2L4> (Year: 2018). [cited by applicant]