Dry-sump, four-stroke engine lubrication device
First Claim
1. A lubrication device for a dry-sump, four-stroke engine, comprising:
- a crankcase having a divider wall;
a crank chamber and a separate chamber with the divider wall interposed in between the crank chamber and separate chamber;
a crankshaft housed in the crank chamber, driven by a reciprocating movement of pistons, and having a crank web facing the divider wall;
a through hole formed in the divider wall or connecting the crank chamber with the separate chamber, and opened by the crank web when the piston moves from a top dead center position toward a bottom dead center position, and closed by the crank web when the piston moves from the bottom dead center toward the top dead center position;
a return hole connecting the crank chamber and the separate chamber, for returning lubricant oil that flowed by way of the through hole into the separate chamber from the crank chamber, back to the crank chamber by utilizing pressure fluctuations within the crank chamber; and
an oil pump that suctions up the lubricant oil from a bottom region of the crank chamber.
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Accused Products
Abstract
A lubrication device for a dry-sump, four-stroke engine includes a crankcase having a divider wall, a crank chamber and a separate adjoining chamber with the divider wall interposed in between the crank chamber and separate chamber. A crankshaft is housed in the crank chamber and is driven by the reciprocating movement of the pistons. A crank web faces the divider wall, and the divider wall has a through hole for connecting the crank chamber with the separate chamber, and is opened by the crank web when the piston moves from a top dead center position toward a bottom dead center position, and is closed by the crank web when the piston moves from the bottom dead center toward the top dead center position. A return hole connects the crank chamber and the separate chamber, for returning lubricant oil that flowed by way of the through hole into the separate chamber from the crank chamber, back to the crank chamber by utilizing pressure fluctuations within the crank chamber.
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Citations
20 Claims
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1. A lubrication device for a dry-sump, four-stroke engine, comprising:
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a crankcase having a divider wall;
a crank chamber and a separate chamber with the divider wall interposed in between the crank chamber and separate chamber;
a crankshaft housed in the crank chamber, driven by a reciprocating movement of pistons, and having a crank web facing the divider wall;
a through hole formed in the divider wall or connecting the crank chamber with the separate chamber, and opened by the crank web when the piston moves from a top dead center position toward a bottom dead center position, and closed by the crank web when the piston moves from the bottom dead center toward the top dead center position;
a return hole connecting the crank chamber and the separate chamber, for returning lubricant oil that flowed by way of the through hole into the separate chamber from the crank chamber, back to the crank chamber by utilizing pressure fluctuations within the crank chamber; and
an oil pump that suctions up the lubricant oil from a bottom region of the crank chamber. - View Dependent Claims (2, 3, 4, 6, 7, 8, 11, 12, 15, 18, 19)
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5. A lubrication device for a dry-sump, four-stroke engine, comprising:
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a crankcase having a divider wall;
a crank chamber and a separate chamber with the divider wall interposed in between the crank chamber and the separate chamber;
a crankshaft housed in the crank chamber, driven by a reciprocating movement of pistons, and having a crank web facing the divider wall;
a through hole formed in the divider wall for connecting the crank chamber with the separate chamber, and opened by the crank web during a period that a positive pressure is generated in the crank chamber, and closed by the crank web in period that a negative pressure is generated in the crank chamber;
a return hole connecting the crank chamber and the separate chamber, for returning lubricant oil that flowed by way of the through hole into the separate chamber from the crank chamber, back to the crank chamber by utilizing pressure fluctuations within the crank chamber; and
an oil pump that suctions up the lubricant oil from a bottom region of the crank chamber. - View Dependent Claims (13, 16)
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9. A lubrication device for a dry-sump, four-stroke engine comprising:
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a crankcase having a sidewall;
a crank chamber and a separate chamber with the sidewall interposed in between the crank chamber and separate chamber;
a crankshaft housed in the crank chamber, driven by a reciprocating movement of pistons, and having a crank web facing the sidewall and a journal section protruding from the crank web;
a bearing armed in the sidewall for supporting the journal section of the crankshaft for a free rotational movement;
multiple concavities open toward the crank chamber and mutually formed at spaced intervals for surrounding the bearing in the sidewall;
a passage hole opening toward the separate chamber, and formed in at least one of the concavities;
a partition plate adjoining the crank web, and affixed to the sidewall to cover the concavities and the passage hole;
a through hole formed in the partition plate, and opened by the crank web when the piston moves from a top dead center position toward a bottom dead center position and closed by the crank web when the piston moves from the bottom dead center position toward the top dead center position;
a return hole connecting the crank chamber and the separate chamber, for returning lubricant oil that flowed by way of the through hole and the passage hole into the separate chamber from the crank chamber, back to the crank chamber by utilizing pressure fluctuations within the crank chamber; and
an oil pump that suctions up the lubricant oil from a bottom region of the crank chamber. - View Dependent Claims (10, 14, 17, 20)
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Specification