Crankshaft for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10107327-B2
Application number	US-201615285902-A
Country	US
Kind code	B2
Filing date	Oct 5, 2016
Priority date	Oct 5, 2015
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A crankshaft for an internal combustion engine includes a shaft body having a body rotation axis, with at least one crank pin for coupling a connecting rod to the crankshaft. The crank pin is connected to the shaft body in an offset manner with respect to the body rotation axis by two crank arms. Each arm has an arm surface facing one to the other with the crank pin extending between the arm surfaces. At least one of the arm surfaces is provided with a protrusion extending from the arm surface and configured to avoid contact between the arm surface and the connecting rod.

First claim

What is claimed is:

1. A forged crankshaft for an internal combustion engine comprising:
a shaft body having a body rotation axis;
a crank pin configured to couple the crankshaft to a connecting rod; and
two crank arms connecting the crank pin to the shaft body in an offset manner with respect to the body rotation axis, each crank arm having an arm surface facing one to the other, wherein the crank pin extends between the arm surfaces, and wherein at least one of the arm surfaces comprises a forging parting line at the crank pin and a protrusion extending from the arm surface to prevent contact between the arm surface and the connecting rod, wherein a distance between the forging parting line and the protrusion is at least 3 mm.

2. The crankshaft according to claim 1 , wherein the protrusion at least partially surrounds an end of the crank pin.

3. The crankshaft according to claim 2 , wherein the protrusion is substantially annular.

4. The crankshaft according to claim 1 , wherein the protrusion is substantially annular.

5. The crankshaft according to claim 1 , wherein the protrusion has a thickness in a range between 0.2 mm and 0.8 mm.

6. The crankshaft according to claim 5 , wherein the protrusion has a thickness equal to 0.5 mm.

7. The crankshaft according to claim 1 , wherein at least portion of the protrusion has a width measured in radial direction with respect to a longitudinal axis of the crank pin of about 5 mm.

8. The crankshaft according to claim 1 , wherein the protrusion is in one piece with the crank arm.

9. An internal combustion engine comprising:
a forged crankshaft including a shaft body having a body rotation axis, a crank pin, and two crank arms connecting the crank pin to the shaft body in an offset manner with respect to the body rotation axis, each crank arm having an arm surface facing one to the other, wherein the crank pin extends between the arm surfaces, and wherein at least one of the arm surfaces comprises a forging parting line at the crank pin and a protrusion extending from the arm surface, wherein a distance between the forging parting line and the protrusion is at least 3 mm; and
a connecting rod coupled to the crank pin and spaced from the arm surface by the protrusion which prevents contact between the arm surface and the connecting rod.

Assignees

• Gm Global Tech Operations Llc

Inventors

• NUMIDI Fabio
• Sperlinga Giuliano

Classifications

• F02B75/32

  Engines characterised by connections between pistons and main shafts and not specific to preceding main groups · CPC title

• F16C7/023

  for piston engines, pumps or the like · CPC title

• F16C2360/22

  Internal combustion engines · CPC title

• F16C2220/46

  by forging · CPC title

• F16C3/08 Primary

  made in one piece (features relating to lubrication F16C3/14, to cooling F16C3/16) · CPC title