Cam drive system for an engine

Patent metadata

Field	Value
Publication number	US-10422253-B2
Application number	US-201715482667-A
Country	US
Kind code	B2
Filing date	Apr 7, 2017
Priority date	Apr 26, 2016
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Methods and systems are provided for a cam drive system of an engine. In one example, a front end of an engine includes an idler gear assembly including an idler gear and idler pulley, the idler gear in meshing engagement with a first end of a crankshaft and the idler pulley coupled to and sharing a rotational axis with the idler gear. The front end of the engine may further include first and second camshaft pulleys positioned vertically above the idler gear assembly and a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley.

First claim

The invention claimed is:

1. A front end of an engine, comprising:
a first end of a crankshaft;
an idler gear assembly including an idler gear and an idler pulley, the idler gear in meshing engagement with the first end of the crankshaft and the idler pulley coupled to and sharing a rotational axis with the idler gear;
first and second camshaft pulleys positioned vertically above the idler gear assembly;
a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley; and
a fuel pump drive gear in direct meshing engagement with the idler gear, the fuel pump drive gear directly coupled to a drive shaft of a fuel pump, where the fuel pump is positioned between, in a direction of the rotational axis of the idler gear, pistons of the engine and the idler gear and the fuel pump drive gear.

2. The front end of claim 1 , wherein the cam drive belt does not contact the crankshaft and wherein the idler pulley is arranged in front of the idler gear, closer to a front cover of the front end than the idler gear.

3. The front end of claim 2 , further comprising an oil pump drive gear drivingly coupled to the first end of the crankshaft via an oil pump drive belt, wherein the oil pump drive belt, the oil pump drive gear, the cam drive belt, the first and second camshaft pulleys, and the idler pulley are all arranged in a same plane at the front end of the engine.

4. The front end of claim 1 , wherein the front end of the engine is arranged opposite to a back end of the engine, the back end including a flywheel coupled to a second end of the crankshaft, wherein cylinders of the engine are positioned in an in-line configuration, a piston of the pistons positioned within each cylinder, and wherein the fuel pump is positioned in front of, in the direction of the rotational axis and relative to the front end, all pistons of the engine.

5. The front end of claim 1 , wherein the first and second camshaft pulleys have a same diameter and are positioned adjacent to one another at a top side of the front end of the engine relative to a vertical axis of the engine, the top side arranged opposite a bottom side of the engine, the bottom side including an oil pan and wherein the engine is a diesel engine.

6. The front end of claim 1 , wherein the idler pulley has a smaller diameter than the idler gear and wherein the cam drive belt contacts an outer circumferential surface of the idler pulley.

7. The front end of claim 1 , wherein the first end of the crankshaft rotates in a first direction, the idler gear assembly rotates in a second direction, opposite the first direction, and the first and second camshaft pulleys rotate in the second direction and wherein the fuel pump drive gear being in direct meshing engagement with the idler gear includes teeth of the fuel pump drive gear being in meshing engagement with teeth of the idler gear.

8. The front end of claim 1 , further comprising a first end of a first camshaft directly coupled to the first camshaft pulley and a second end of a second camshaft directly coupled to the second camshaft pulley, wherein the first and second camshafts rotate in a direction opposite a direction of rotation of the first end of the crankshaft.

9. The front end of claim 1 , wherein the idler gear has 63 teeth, the first end of the crankshaft has 45 teeth, and each of the first and second camshaft pulleys has 21 teeth.

10. The front end of claim 1 , wherein the fuel pump is a diesel fuel injection pump and is positioned vertically above the crankshaft and vertically below an EGR cooler.

11. A method for an engine, comprising:
transmitting rotational motion from a crankshaft to an idler gear, the idler gear meshing with a first end of the crankshaft via a plurality of interlocking teeth;
rotating an idler pulley directly coupled with the idler gear via rotation of the idler gear, the idler gear and the idler pulley sharing a rotational axis;
driving rotation of first and second camshaft pulleys through a cam drive belt driven by the idler pulley, the cam drive belt contacting an outer surface of the first and second camshaft pulleys and the idler pulley;
driving rotation of a fuel pump drive gear in direct meshing engagement with the idler gear, via rotation of the idler gear, the fuel pump drive gear directly coupled to a drive shaft of a fuel pump; and
adjusting an amount of gap between teeth of the idler gear and the fuel pump drive gear via adjusting a relative position between teeth of a first toothed disc and teeth of a second toothed disc of a scissor gear, where the scissor gear is one of the fuel pump drive gear and the idler gear.

12. The method of claim 11 , wherein transmitting rotational motion from the crankshaft to the idler gear includes rotating the crankshaft in a first direction and rotating the idler gear in a second direction, opposite the first direction, wherein rotating the idler pulley includes rotating the idler pulley in the second direction, and wherein the first toothed disc is fixedly coupled to a bearing of the scissor gear and the second tooth disc is rotatably coupled to the bearing.

13. The method of claim 12 , further comprising rotating a first camshaft directly coupled to the first camshaft pulley in the second direction and rotating a second camshaft directly coupled to the second camshaft pulley in the second direction.

14. The method of claim 13 , wherein driving rotation of the first and second camshaft pulleys includes rotating the first and second camshaft pulleys at half a speed of rotation of the first camshaft and the second camshaft.

15. The method of claim 11 , wherein the idler gear, the idler pulley, and the first and second camshaft pulleys are all arranged at a front end of the engine, the front end opposite a back end of the engine including a flywheel of the engine and wherein the fuel pump is positioned between, in a direction of a rotational axis of the idler gear, pistons of the engine and the idler gear and the fuel pump drive gear, where the fuel pump is further positioned vertically above the crankshaft.

16. A system for an engine, comprising:
a front end, comprising:
a first end of a crankshaft;
an idler gear assembly including an idler gear and an idler pulley, the idler gear in meshing engagement with the first end of the crankshaft and the idler pulley coupled to and sharing a rotational axis with the idler gear;
first and second camshaft pulleys coupled to first and second camshafts, respectively;
a cam drive belt contacting each of the first and second camshaft pulleys and the idler pulley and not the first end of the crankshaft;
a fuel pump drive gear in direct meshing engagement with the idler gear, the fuel pump drive gear directly coupled to a drive shaft of a fuel injection pump, where the fuel injection pump is positioned more interior to the engine than the front end of the engine and vertically above the crankshaft, the fuel injection pump positioned between, in a direction of the rotational axis of the idler gear, pistons of the engine and the idler gear and the fuel pump drive gear, where cylinders of the engine, each adapted to receive a piston of the pistons, are arranged inline; and
an oil pump drive gear in meshing engagement with a crankshaft pulley directly coupled to the first end of the crankshaft and directly coupled to an input shaft of an oil pump, wherein an oil pump belt contacts each of the crankshaft pulley and the oil pump drive gear, where the oil pump belt and the cam drive belt are arranged in a same plane; and

a back end arranged opposite the front end, the back end i

Assignees

• Ford Global Tech Llc

Inventors

• Turner Paul Nigel
• Maile Kevin John
• Raines Chris Michael

Classifications

• F16H7/14

  of a driving or driven pulley · CPC title

• F16H2007/0893

  Circular path · CPC title

• F16H2007/0865

  Pulleys · CPC title

• F01M2001/0269

  driven by the crankshaft · CPC title

• F01L1/026

  Gear drive · CPC title