INTERNAL COMBUSTION ENGINE INCLUDING A MASS DIFFERENTIAL GEAR INCLUDING TWO BALANCE SHAFTS

Abstract

An internal combustion engine includes a crankcase in which a crankshaft is rotatably mounted in bearings including bearing covers, to which at least one connecting rod carrying a piston is linked. The piston is movable in a cylinder covered by a cylinder head forming a combustion chamber and gas exchange valves are arranged in the cylinder head, which are actuated by at least one camshaft, which is connected to a gear train gear wheel situated on the crankshaft via a differential gear. A mass differential gear including two balance shafts is present. The mass differential gear is situated in a gear frame and attached to the crankcase below the crankshaft and driven by a mass shaft drive gear situated on the crankshaft, which is arranged axially essentially next to the gear train gear wheel/idler gear. The gear train gear wheel/idler gear is arranged on the main bearing cover.

Claims

1-4. (canceled)

5. An internal combustion engine including a crankcase in which a crankshaft is rotatably mounted in bearings including bearing covers, to which at least one connecting rod carrying a piston is linked, the piston being movable in a cylinder covered by a cylinder head, forming a combustion chamber, and gas exchange valves being situated in the cylinder head, which are actuated by at least one camshaft connected via a gear mechanism to a gear train gear wheel situated on the crankshaft, the internal combustion engine further comprising: a mass differential gear including two balance shafts being present, that the mass differential gear, situated in a gear frame, being attached to the crankcase beneath the crankshaft and driven by a mass shaft drive gear situated on the crankshaft, which is axially situated next to the gear train gear wheel/an idler gear, and the gear train gear wheel/the idler gear being situated at a main bearing cover.

6. The internal combustion engine as recited in claim 5, wherein an lubricating oil supply of an idler gear bearing is tapped from a lubricating oil supply of a main bearing on a crankcase-side in such a way that a supply borehole of a crankcase-side bearing block is partially drilled by which oil is forwarded to the idler gear.

7. The internal combustion engine as recited in claim 5, wherein a lubricating oil supply of an idler gear bearing is tapped from a lubricating oil supply of a main bearing on a crankcase-side in such a way that the oil supply of the idler gear bearing takes place by a bearing shell which is installed on the crankcase-side and includes an integrated rear-side oil supply groove.

8. A method for operating the internal combustion engine as recited in claim 5 comprising: driving the mass differential gear via the mass shaft drive gear situated on the crankshaft.

9. An internal combustion engine comprising: a crankcase; a crankshaft is rotatably mounted in the crankcase; a crankshaft gear situated on the crankshaft; a gear frame fixed to a bottom of the crankcase; a mass differential gear situated in a gear frame beneath the crankshaft gear; an intermediate gear; and a bearing cover, the mass differential gear being driven by the crankshaft gear via the intermediate gear, the intermediate gear being situated at the bearing cover.

10. The internal combustion engine as recited in claim 9 wherein the intermediate gear is an idler gear fastened to the bearing cover by a fastener held in the bearing cover.

11. The internal combustion engine as recited in claim 9 wherein the idler gear includes a bearing pin fixed to the bearing cover by the fastener and at least one bearing for rotatably coupling the idler gear to the bearing cover.

12. The internal combustion engine as recited in claim 9 further comprising a drive wheel of an oil pump operatively connected to the crankshaft gear.

13. The internal combustion engine as recited in claim 9 wherein the bearing cover includes an oil supply for suppling oil to a bearing of the intermediate gear.

14. The internal combustion engine as recited in claim 9, wherein the intermediate gear is an idler gear and a lubricating oil supply of an idler gear bearing of the idler gear is tapped from a lubricating oil supply of a main bearing on a crankcase-side in such a way that a supply borehole of a crankcase-side bearing block is partially drilled by which oil is forwarded to the idler gear.

15. The internal combustion engine as recited in claim 9, wherein the intermediate gear is an idler gear and a lubricating oil supply of an idler gear bearing of the idler gear is tapped from a lubricating oil supply of a main bearing on a crankcase-side in such a way that the oil supply of the idler gear bearing takes place by a bearing shell which is installed on the crankcase-side and includes an integrated rear-side oil supply groove.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Further advantageous embodiments of the present disclosure may be derived from the description of the drawings, in which an exemplary embodiment shown in the figures is described in greater detail:

[0012] FIG. 1a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a rolling bearing-supported idler gear;

[0013] FIG. 1b shows a cross-sectional view along A-A in FIG. 1a;

[0014] FIG. 2a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a friction bearing-supported idler gear;

[0015] FIG. 2b shows a cross-sectional view along B-B in FIG. 2a;

[0016] FIG. 2c shows a cross-sectional view along C-C in FIG. 2a;

[0017] FIG. 3a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a rolling bearing-supported idler gear;

[0018] FIG. 3b shows a cross-sectional view along A-A in FIG. 1a;

[0019] FIG. 4a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a friction bearing-supported idler gear;

[0020] FIG. 4b shows a cross-sectional view along B-B in FIG. 4a; and

[0021] FIG. 4c shows a cross-sectional view along C-C in FIG. 4a.

DETAILED DESCRIPTION

[0022] A gear train gear wheel and a mass shaft drive wheel are non-rotatably attached on the extension of the crankshaft, as is shown in FIG. 1a. The gear train gear wheel is engaged with a stepped gear wheel, which in turn meshes with a camshaft gear wheel. An oil pump gear wheel, which is an integral part of an oil pump situated in the gear train housing, is also driven by the gear train gear wheel.

[0023] Crankshaft gear wheel 1 is attached to the crankshaft 19 and is operatively connected to mass balance shafts 4 with the aid of the idler gear screwed onto bearing cover 2. A centering receptacle 5 is situated in the bearing cover at bearing cover 2. Furthermore, crankshaft gear wheel 1 attached at the crankshaft is operatively connected to the idler gear of oil pump 6, which is in turn operatively connected to the drive wheel of the oil pump 7. The screwed-on bearing pin 8 accommodates a rolling bearing-supported idler gear 3 including screw 16 and rolling bearing 15 screwed onto bearing cover 2.

[0024] In the view according to FIG. 2a, a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a friction bearing-supported idler gear is shown.

[0025] The mass differential gear is driven via a balance shaft idler gear, which in turn drives a drive wheel situated axially upstream from a balance shaft gear wheel, which is engaged with a second balance shaft gear wheel.

[0026] These two balance shaft gear wheels are connected to the mass balance shafts 20 (FIG. 1a) mounted in gear frame 17 of the mass differential gear. This gear frame is screwed directly to the underside of the crankcase 18 (FIG. 1a). Crankshaft gear wheel 1 is attached to the crankshaft and is operatively connected to mass balance shafts 4 with the aid of idler gear 3 screwed onto bearing cover 2. Furthermore, crankshaft gear wheel 1 attached to the crankshaft is operatively connected to idler gear 3, which is in turn operatively connected to the drive wheel of the oil pump 7. The cast-on bearing pin 9 accommodates a friction bearing-supported idler gear 3, and which is screwed onto bearing cover 2 using thrust washer 10 and screw 16. The annular gap for oil supply 11 is supplied with oil for oil supply 13 of friction bearing 14 from annular gap 11 with the aid of oil flow 12 from bearing block borehole into the annular gap.

[0027] The representation in FIG. 3a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a rolling bearing-supported idler gear 3. Crankshaft gear wheel 1 is attached to the crankshaft and is operatively connected to mass balance shafts 4 with the aid of the idler gear screwed onto bearing cover 2. A centering receptacle 5 is situated in the bearing cover at bearing cover 2. Furthermore, crankshaft gear wheel 1 attached to the crankshaft is operatively connected to the idler gear of oil pump 6, which is in turn operatively connected to the drive wheel of the oil pump 7. The screwed-on bearing pin 8 accommodates a rolling bearing-supported idler gear 3, including screw 16 and rolling bearing 15 screwed onto bearing cover 2.

[0028] FIG. 4a shows a front view of the internal combustion engine including a partially mounted gear train including a differential gear and a friction bearing-supported idler gear 3. Crankshaft gear wheel 1 is attached to the crankshaft and is operatively connected to mass balance shafts 4 with the aid of idler gear 3 screwed onto bearing cover 2. Furthermore, crankshaft gear wheel 1 attached to the crankshaft is operatively connected to idler gear 3, which is in turn operatively connected to the drive wheel of oil pump 7. The cast-on bearing pin 9 accommodates a friction bearing-supported idler gear 3 which is screwed onto bearing cover 2 with the aid of thrust washer 10 and screw 16. The annular gap for oil supply 11 is supplied with oil for oil supply 13 of friction bearing 14 from annular gap 11 with the aid of oil flow 12 from bearing block borehole into the annular gap.

LIST OF REFERENCE NUMERALS

[0029] 1 crankshaft gear wheel [0030] 2 bearing cover [0031] 3 idler gear screwed onto bearing cover [0032] 4 mass balance shafts [0033] 5 centering receptacle in bearing cover [0034] 6 oil pump idler gear [0035] 7 drive wheel of oil pump [0036] 8 bearing pin screwed on [0037] 9 bearing pin cast onto bearing cover [0038] 10 thrust washer [0039] 11 annular gap for oil supply [0040] 12 oil flow from bearing block borehole into annular gap [0041] 13 oil supply of friction bearing from annular gap [0042] 14 friction bearing of idler gear [0043] 15 rolling bearing of idler gear [0044] 16 screw [0045] 17 gear frame [0046] 18 crankcase [0047] 19 crankshaft [0048] 20 mass balance shafts