Vee engine dual inboard camshaft system

Patent metadata

Field	Value
Publication number	US-10458326-B2
Application number	US-201715418398-A
Country	US
Kind code	B2
Filing date	Jan 27, 2017
Priority date	Jan 27, 2017
Publication date	Oct 29, 2019
Grant date	Oct 29, 2019

Abstract

An internal combustion engine includes a cylinder case that includes a first geartrain disposed on a front end of the cylinder case and a second geartrain disposed on a rear end of the cylinder case. The first geartrain drives a first camshaft, and the second geartrain drives a second camshaft, the first and second camshafts having respective rotational axes that are parallel.

First claim

We claim:

1. An internal combustion engine, comprising:
a cylinder case rotatably supporting a crankshaft having a front end and a rear end;
a first geartrain disposed on a front end of the cylinder case, the first geartrain being meshably connected with a first driving gear connected to the front end of the crankshaft;
a second geartrain disposed on a rear end of the cylinder case, the second geartrain being meshably connected with a second driving gear connected to the rear end of the crankshaft;
a first camshaft rotatably supported relative to the cylinder case, the first camshaft having a first rotational axis and having a first driven gear connected to a front end of the first camshaft, the first driven gear being meshably connected to the first geartrain, wherein the first camshaft operates intake and exhaust valves associated with cylinders formed in the cylinder case;
a second camshaft rotatably supported relative to the cylinder case, the second camshaft having a second rotational axis and having a second driven gear connected to a rear end of the second camshaft, the second driven gear being meshably connected to the second geartrain, wherein the second camshaft operates unit fuel injectors associated with the cylinders formed in the cylinder case;
wherein the first rotational axis and the second rotational axis are parallel, and wherein the intake and exhaust valves operate independently from the unit fuel injectors.

2. The internal combustion engine of claim 1 , further comprising a rotational axis of the crankshaft, wherein the rotational axis of the crankshaft is parallel to the first rotational axis and the second rotational axis.

3. The internal combustion engine of claim 1 , wherein the cylinder case has a Vee configuration that includes a first plurality of cylinders arranged along a first bank and a second plurality of cylinders arranged along a second bank, wherein a valley is defined between the first bank and the second bank, and wherein the first and second camshafts are disposed in the valley.

4. The internal combustion engine of claim 3 , wherein each cylinder in the first plurality of cylinders and the second plurality of cylinders includes an intake valve operated by an intake rocker and a pushrod, and an exhaust valve operated by an exhaust rocker and an additional pushrod, wherein each of the pushrod and the additional pushrod includes a roller tappet, and wherein the roller tappets ride on lobes formed on the first camshaft.

5. The internal combustion engine of claim 3 , wherein each cylinder in the first plurality of cylinders and the second plurality of cylinders includes a mechanical unit fuel injector operated by an injector rocker and an injector roller tappet, and wherein the injector roller tappet rides on a lobe formed on the second camshaft.

6. The internal combustion engine of claim 5 , further comprising a spring disposed to provide a biasing force that pushes the injector roller tappet into contact with the lobe formed on the second camshaft.

7. The internal combustion engine of claim 3 , wherein the first camshaft is disposed below the second camshaft in the valley.

8. The internal combustion engine of claim 1 , wherein the first geartrain includes at least one idler gear.

9. The internal combustion engine of claim 1 , wherein the second geartrain includes at least one idler gear.

10. The internal combustion engine of claim 1 , wherein the first geartrain is configured to rotate the first camshaft at a different speed than the second geartrain is configured to rotate the second camshaft for any given rotation speed of the crankshaft.

11. The internal combustion engine of claim 1 , wherein the first geartrain includes at least one idler gear, and wherein the second geartrain includes at least one idler gear.

12. An internal combustion engine, comprising:
a cylinder case rotatably supporting a crankshaft having a front end and a rear end;
a first geartrain configured to be directly driven by the front end of the crankshaft;
a first camshaft rotatably supported relative to the cylinder case, the first camshaft having a first rotational axis and being driven directly by the first geartrain;
a second geartrain configured to be directly driven by the rear end of the crankshaft, the second geartrain being independent from the first geartrain;
a second camshaft rotatably supported relative to the cylinder case, the second camshaft having a second rotational axis and being driven directly by the second geartrain;
wherein the first rotational axis and the second rotational axis are parallel;
wherein the first and second camshafts are arranged to rotate at different speeds for any given rotation speed of the crankshaft; and
wherein the cylinder case has a Vee configuration that includes a first plurality of cylinders arranged along a first bank and a second plurality of cylinders arranged along a second bank, wherein a valley is defined between the first bank and the second bank, and wherein the first and second camshafts are disposed in the valley.

13. The internal combustion engine of claim 12 , wherein the second camshaft has a second driven gear connected to a rear end of the second camshaft, the second driven gear being meshably connected to the second geartrain.

14. The internal combustion engine of claim 12 , wherein the first camshaft has a first driven gear connected to a front end of the first camshaft, the first driven gear being meshably connected to the first geartrain.

15. The internal combustion engine of claim 12 , wherein the first geartrain is disposed on a front end of the cylinder case, the first geartrain being meshably connected with a first driving gear connected to the front end of the crankshaft, and wherein the second geartrain is disposed on a rear end of the cylinder case, the second geartrain being meshably connected with a second driving gear connected to the rear end of the crankshaft.

16. The internal combustion engine of claim 12 , further comprising a rotational axis of the crankshaft, wherein the rotational axis of the crankshaft is parallel to the first rotational axis and the second rotational axis.

17. The internal combustion engine of claim 12 , wherein each cylinder in the first plurality of cylinders and the second plurality of cylinders includes:
an intake valve operated by an intake rocker and a pushrod;
an exhaust valve operated by an exhaust rocker and an additional pushrod, wherein each of the pushrod and the additional pushrod includes a roller tappet, and wherein the roller tappets ride on lobes formed on the first camshaft;
a mechanical unit fuel injector operated by an injector rocker and an injector roller tappet, wherein the injector roller tappet rides on a lobe formed on the second camshaft.

18. The internal combustion engine of claim 12 , wherein the first camshaft is disposed below the second camshaft in the valley.

Assignees

• Caterpillar Inc

Inventors

• Hittle Craig P

Classifications

• F02B2075/1864

  sixteen · CPC title

• F02B2075/1848

  twelve · CPC title

• F02B67/04

  of mechanically-driven auxiliary apparatus · CPC title

• F01L1/026

  Gear drive · CPC title

• F01L2305/00

  Valve arrangements comprising rollers · CPC title