WO2010025611A1

WO2010025611A1 - A gear assembly for an engine

Info

Publication number: WO2010025611A1
Application number: PCT/CN2009/000766
Authority: WO
Inventors: 肖亨琳
Original assignee: 无锡开普机械有限公司
Priority date: 2008-09-03
Filing date: 2009-07-06
Publication date: 2010-03-11

Abstract

A gear assembly for an engine is disclosed. A bottom plate (2) is fixed on an engine body (1); a central shaft (11), a first idler gear shaft (12), a camshaft (13), a second idler gear shaft (14) and an output shaft (15) are mounted on the bottom plate (2); a larger gear (4) and a smaller gear (5) are coaxially mounted on the central shaft (11); the larger gear (4) engages with a crankshaft timing gear (3); a camshaft driven gear (7) is mounted on the camshaft (13); a first idler gear (6) is mounted on the first idler gear shaft (12) and a second idler gear (8) is mounted on the second idler gear shaft (14); the smaller gear (5) engages with the first idler gear (6) and the second idler gear (8), respectively; the first idler gear (6) engages with the camshaft driven gear (7); the second idler gear (8) engages with an injection pump gear (9) which is fixed on the output shaft (15). The volume of the whole gearbox becomes small, and it may be ensured that the rotational velocities of the camshaft driven gear and the injection pump gear are half of that of the camshaft timing gear.

Description

Engine gear transmission

Technical field

The present invention relates to a gear transmission of an engine, and more particularly to a gear transmission structure of an engine, which belongs to the technical field of internal combustion engines.

Background technique

For a four-stroke engine, each cylinder is in and out once every one working cycle, that is, the crankshaft rotates for two weeks, and the camshaft rotates only one revolution, so the transmission ratio of the crankshaft to the camshaft is 2:1; similarly, the crankshaft The transmission ratio to the fuel pump drive gear is also required to be 2:1. Existing engine gear trains are typically disposed within the gear housing of the engine block. The gear chamber is equipped with components such as the crankshaft timing gear and the idler gear. After passing through the multi-speed shifting drive, the 2:1 transmission ratio requirements of the crankshaft timing gear and the camshaft drive gear and the fuel injection drive gear can be achieved. This kind of crusted engine, because only considering the transmission ratio requirements, does not consider the size of the gear chamber and the size of the transmission gear, resulting in a large number of gears, the gear chamber is difficult to achieve a small form factor, and the fuel injection pump gear And the camshaft drive gear is also difficult to achieve small size.

Summary of the invention

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned deficiencies, and to provide a gear transmission of an engine which can ensure a correct transmission ratio and is small in volume.

According to the technical solution provided by the present invention, the gear transmission of the engine includes an engine body, a crankshaft timing gear, a camshaft drive gear, a fuel injection pump gear, a crankshaft, and a camshaft. The crankshaft is mounted in the body, and the crankshaft timing gear is mounted on the crankshaft. The feature is: the engine body is fixed on the bottom plate, and the central shaft, the first idle gear shaft, the cam shaft, the second idle gear shaft and the output shaft are mounted on the bottom plate, and the large shaft and the pinion gear are coaxially mounted on the central shaft) The large gear meshes with the crankshaft timing gear, the camshaft drive gear is mounted on the camshaft, the first idler gear is mounted on the first idler gear shaft, and the second idler gear is mounted on the second idler gear shaft, the pinion gears respectively The first idler gear meshes with the second idler gear, the first idler gear meshes with the camshaft drive gear, the second idler gear meshes with the fuel injection pump gear, and the fuel injection pump gear is fixed to the output shaft.

The gear ratio of the large gear to the crankshaft timing gear is 2: 1. The number of teeth of the pinion gear is equal to the number of teeth of the camshaft drive gear and the fuel injection pump gear.

A gear chamber cover is disposed on the bottom plate. A recessed hole is disposed on an inner surface of the gear chamber cover, and a shaft head is disposed at an end of the central shaft, and the recessed hole cooperates with the shaft head. The present invention has the following advantages over the prior art:

1. The invention is driven by coaxially mounted large and small gears and first and second idle gears, and has a simple structure and a clear principle.

2. The large and small gears are mounted coaxially, and the pinion gear has fewer teeth than the large gear, which can save radial space, so the volume of the entire gear chamber becomes smaller.

3. The idler gear does not change the transmission ratio, and the gear ratio of the large gear to the crankshaft timing gear is 2:1. The number of teeth of the pinion gear is equal to the number of teeth of the camshaft drive gear and the fuel injection pump gear, so that the camshaft drive gear can be guaranteed. And the speed of the fuel injection pump gear is half of the crankshaft timing gear.

4. The gear chamber cover is positioned on the bottom plate through the cooperation of the concave hole and the shaft head, and the positioning is simple and reliable.

DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a front elevational view of the structure of the present invention with the gear chamber cover removed.

Figure 2 is a cross-sectional view taken along line A-A of Figure 1.

Figure 3 is a cross-sectional view taken along line B-B of Figure 1.

detailed description

The invention will be further described below in conjunction with the embodiments of the drawings:

1 to 3, including the body 1, the bottom plate 2, the crank timing gear 3, the large gear 4, the pinion 5, the first idle gear 6, the cam shaft drive gear 7, the second idle gear 8, the fuel injection pump gear 9, a crankshaft 10, a center shaft 11, a first idler gear shaft 12, a camshaft 13, a second idler gear shaft 14, an output shaft 15, a gear chamber cover 16, a recessed hole 17, a shaft head 18, and the like.

As shown in Figs. 1 to 3, the bottom plate 2 of the present invention is fixed to the front end surface of the engine block 1, the crank shaft 10 is mounted in the body 1, and the crank timing gear 3 is mounted on the crankshaft 10. The center shaft 11, the first idle gear shaft 12, the cam shaft 13, the second idle gear shaft 14, and the output shaft 15 are attached to the bottom plate 2 by bolts, respectively. A large gear 4 and a pinion 5 are coaxially mounted on the center shaft 11, the large gear 4 meshes with the crank timing gear 3, the cam shaft drive gear 7 is mounted on the cam shaft 13, and the first idle gear 6 is mounted on the first idle gear On the shaft 12, the second idler gear 8 is mounted on the second idler gear shaft 14. The pinion gear 5 meshes with the first idle gear 6 and the second idle gear 8, the first idle gear 6 meshes with the cam shaft drive gear 7, and the second idle gear 8 meshes with the fuel injection pump gear 9. The camshaft drive gear 7 is mounted on the camshaft 13, and the fuel injection pump gear 9 is fastened to the output shaft 15 by bolts. The gear ratio of the large gear 4 to the crankshaft timing gear 3 is 2: 1, and the number of teeth of the pinion 5 is equal to the number of teeth of the camshaft drive gear 7 and the fuel injection pump gear 9.

A gear chamber cover 16 is disposed on the bottom plate 2. A recessed hole 17 is provided on the inner surface of the gear chamber cover 16, and a shaft head 18 is provided at the end of the center shaft 11, and the recessed hole 17 is engaged with the shaft head 18. Gear chamber cover 16 passes The engagement of the recess 17 with the shaft head 18 is positioned on the base plate 2.

The transmission process of the present invention is as follows -

(1) Camshaft transmission route: The gear ratio of the crankshaft timing gear 3 and the large gear 4 is set to 1:2, the rotational speed transmitted to the large gear 4 through the crankshaft timing gear 3 is reduced by half, and then the speed is transmitted through the large gear 4 The same pinion 5 transmits power to the first idle gear 6. Since the pinion 5 has a small number of teeth, the volume becomes small. The first idler gear 6 transmits power to the camshaft drive gear 7. Since the first idler gear 6 does not change the gear ratio, the rotational speed of the camshaft drive gear 7 is the same as that of the pinion 5, that is, the rotational speed of the camshaft drive gear 7 is the crankshaft. The timing gear 3 is half the speed.

(2) Fuel injection pump transmission route: a part of the power of the pinion 5 is transmitted to the second idle gear 8, and the second idle gear 8 transmits power to the injection pump gear 9, since the second idle gear 8 does not change the transmission ratio, Therefore, the rotational speed of the fuel injection pump gear 9 is the same as that of the small gear 5, that is, the rotational speed of the fuel injection pump gear 9 is half of the rotational speed of the crank gear.

Claims

Rights request

1. An engine gear transmission comprising an engine body (1), a crankshaft timing gear (3), a camshaft drive gear (7), a fuel injection pump gear (9), a crankshaft (10), and a camshaft (13) And output shaft

(15), the crankshaft (10) is installed in the body (1), and the crankshaft timing gear (3) is mounted on the crankshaft (10); the characteristic is: the engine body (1) is fixed on the bottom plate (2), A central shaft (11), a first idler gear shaft (12), a cam shaft (13), a second idler gear shaft (14) and an output shaft (15) are mounted on the bottom plate (2), and the central shaft (11) is coaxial Large gear (4) and pinion (5), large gear

(4) meshing with the crankshaft timing gear (3), the camshaft drive gear (7) is mounted on the camshaft (13), and the first idler gear (6) is mounted on the first idler gear shaft (12), second The idler gear (8) is mounted on the second idler gear shaft (14), and the pinion gear (5) meshes with the first idle gear (6) and the second idle gear (8), respectively, the first idle gear (6) and the cam The shaft drive gear (7) is engaged, the second idle gear (8) is meshed with the fuel injection pump gear (9), and the fuel injection pump gear (9) is fixed to the output shaft (15).

The gear transmission of an engine according to claim 1, characterized in that the gear ratio of the large gear (4) to the crank timing gear (3) is 2:1.

A gear transmission for an engine according to claim 1, wherein the number of teeth of said pinion (5) is equal to the number of teeth of the cam shaft drive gear (7) and the fuel injection pump gear (9).

A gear transmission for an engine according to claim 1, characterized in that the bottom plate (2) is provided with a gear chamber cover (16).

The gear transmission of an engine according to claim 4, characterized in that the inner surface of the gear chamber cover (16) is provided with a recessed hole (17).

The gear transmission of an engine according to claim 1, characterized in that the end of the central shaft (11) is provided with a shaft head (18), and the shaft head (18) is matched with the recessed hole (17). .