Internal combustion engine with improved lubrication circuit

Patent metadata

Field	Value
Publication number	US-11111829-B2
Application number	US-201816754781-A
Country	US
Kind code	B2
Filing date	Oct 15, 2018
Priority date	Oct 18, 2017
Publication date	Sep 7, 2021
Grant date	Sep 7, 2021

Abstract

An internal combustion engine including a crank chamber housing a crankshaft connected to moving parts able to supply torque to the crankshaft, a lubrication circuit, an oil sump for collecting the lubricating oil, the engine including a separating partition which separates the crank chamber from the oil sump, in which the lubrication circuit includes a first oil pump and a second oil pump, where the first oil pump is fluidically connected in aspiration to the crank chamber and in delivery to the oil sump, the second oil pump being fluidly connected in aspiration to the oil sump and in delivery to the crank chamber by means of the lubrication circuit, to re-introduce pressurised oil in the crank chamber and lubricate the moving parts.

First claim

The invention claimed is:

1. The internal combustion engine comprising:
a crank chamber which houses a crankshaft connected to moving parts able to supply torque to said crankshaft,
a lubrication circuit configured to lubricate with lubricant oil said crankshaft and/or said moving parts,
an oil sump to collect said lubricant oil,
a separating partition which separates the crank chamber from the oil sump,
wherein the lubrication circuit comprises a first oil pump and a second oil pump,
wherein the first oil pump is fluidically connected in aspiration to the crank chamber and in delivery to the oil sump, the second oil pump is fluidly connected in aspiration to the oil sump and in delivery to the crank chamber by the lubrication circuit, to re-introduce the oil in the crank chamber and lubricate said moving parts,
wherein the crank chamber comprises an oil scraper fin substantially counter-shaped with respect to a counterweight of the crankshaft so as to almost skim said counterweight.

2. The internal combustion engine according to claim 1 , wherein said first and second oil pumps are arranged in series with each other.

3. The internal combustion engine according to claim 1 , wherein said first and second oil pumps are dimensioned so that the delivery flow rate of the first oil pump is less than the delivery flow rate of the second oil pump.

4. The internal combustion engine according to claim 1 , wherein the first oil pump is positioned in the vicinity of said separating partition and has a first suction duct of the oil collected on a bottom of said separating partition.

5. The internal combustion engine according to claim 1 , wherein the second oil pump is coaxial with said first oil pump.

6. The internal combustion engine according to claim 1 , wherein said first and/or second oil pumps are positive displacement pumps.

7. The internal combustion engine according to claim 1 , wherein said first and/or second oil pumps are lobed positive displacement pumps.

8. The internal combustion engine according to claim 1 , wherein said first and second oil pumps comprise vanes keyed onto said drive shaft, operatively connected to actuating means.

9. The internal combustion engine according to claim 1 , wherein said oil scraper fin is positioned so as to create a barrier to the spreading of oil relative to the direction of rotation of the crankshaft in operation.

10. The internal combustion engine according to claim 1 , wherein the oil sump is placed under the crank chamber.

11. The internal combustion engine according to claim 1 , wherein the oil sump is connected to the rest of the internal combustion engine to form a single body.

12. A motorcycle comprising an internal combustion engine according to claim 1 .

Assignees

• Piaggio & C Spa

Inventors

• Gatti Giuseppe
• Magherini Adriano

Classifications

• F01M11/0004 Primary

  Oilsumps · CPC title

• F01M2001/123

  using two or more pumps · CPC title

• F01M1/16

  Controlling lubricant pressure or quantity (rendering machines or engines inoperative or idling on lubricant pressure failure F01M1/22) · CPC title

• F01M2011/0083

  Dry sumps · CPC title

• F01M1/02 Primary

  using lubricating pumps (pumps in general F04; lubricating pumps per se F16N) · CPC title