KR20160093696A - Drive arrangement for a fuel pump - Google Patents

Abstract

The present invention relates to a driving apparatus 2 used for a fuel pump 20 mounted on a combustion engine 4 and includes a first gear wheel 24 disposed on a crankshaft 26 of a combustion engine 4, And a second gear wheel (34) disposed on the drive shaft (22) of the pump (20), wherein the crankshaft (24) and the drive shaft (22) are parallel to each other, Wherein the gear wheel (24) and the second gear wheel (34) are arranged to directly engage with each other. The present invention also relates to a combustion engine (4) and a vehicle (1) including such a drive device (2).

Description

[0001] DRIVE ARRANGEMENT FOR A FUEL PUMP [0002]

The present invention relates to a drive apparatus for use in a fuel pump mounted in a combustion engine, a combustion engine having such a drive apparatus, and a vehicle equipped with such a drive apparatus.

Combustion engines, such as diesel engines or auto engines, are used in many types of fields and in mid-sized vehicles such as trucks or buses, passenger cars, motor boats, ships, ferries or boats. Combustion engines are also used in power plants and locomotives such as industrial robots powered by industrial engines and / or motors, and electric power plants including diesel power plants.

The combustion engines can be operated, for example, by diesel or gasoline. These combustion engines are equipped with a fuel system for transporting fuel from one or more fuel tanks to the injection system of the combustion engine. The fuel system includes one or more fuel pumps that can be mechanically driven by a combustion engine or driven by an electric motor. The fuel pump generates the flow and pressure of the fuel to transport the fuel to the injection system of the combustion engine. Thereby, the fuel is supplied to the combustion chamber of the combustion engine.

Suitably, the injection system comprises a high-pressure fuel pump with a pressure accumulator. The high-pressure fuel pump is typically operated mechanically connected to the combustion engine. Such mechanical connections may include, for example, gear wheel transmissions or chain transmissions. When the high-pressure fuel pump is operated by the mechanical connection between the combustion engine and the high-pressure fuel pump, noise may be generated by the components, which adversely affects the surrounding environment. In order to meet the noise regulations applicable to the automobile industry, it is desirable to minimize the noise level in the vehicle as much as possible.

Many methods or systems for operating fuel pumps have been proposed in the prior art. For example, in US2011 / 0005500 A1, a transmission device for a combustion engine is described in which a high-pressure fuel pump is operated by a crankshaft of a combustion engine via a chain transmission system. In the case of a high-pressure fuel pump using this method, the combustion system must be designed specifically, though the drive system is flexible, and has a relatively short life span.

In addition, US1067424 and US2011 / 0209680 disclose a system for injecting fuel into a combustion engine, wherein the fuel pump is driven by a crankshaft of the combustion engine via a gear chain transmission system comprising a plurality of toothed wheels have. This system can generate considerable noise.

Despite these prior art solutions, there is a need to further develop a drive system for a fuel pump that can lower the noise level.

It is an object of the present invention to develop a drive device for a fuel pump that minimizes the noise level.

An object of the present invention is to develop a drive device for a fuel pump that is compact and can be used with a reduced space.

Another object of the present invention is to develop a drive device for a fuel pump that is robust, wear resistant, durable, and relatively long in service life.

These objects of the present invention are achieved by a driving apparatus as defined in claim 1.

According to the present invention, the above-mentioned objects of the present invention are achieved by a driving apparatus for use in a fuel pump mounted on a combustion engine, the driving apparatus comprising a first gear disposed on a crankshaft of a combustion engine, Wherein the crankshaft and the drive shaft are parallel to each other, wherein the crankshaft and the drive shaft are parallel to each other. Further, the first toothed wheels and the second toothed wheels are arranged to directly engage with each other.

The present invention also relates to a combustion engine and a vehicle including the drive device described above.

Hereinafter, the driving apparatus described above will be described.

It is appropriate that the drive unit is disposed in association with the combustion engine and the fuel pump. The drive unit is suitably constituted by a gear transmission which transmits power from the crankshaft of the combustion engine to the drive shaft of the fuel pump to drive the fuel pump.

By disposing the first and second toothed wheels directly in engagement with each other, the noise level in the drive apparatus can be minimized. The first toothed wheels and the second toothed wheels are directly engaged with each other so that the teeth of the first toothed wheels and the toothed wheels of the second toothed wheels are directly engaged with each other so that the intermediate toothed wheels are interposed between the first toothed wheels and the second toothed wheels There is no need. In the pinion gear, vibrations are generated by fluctuations in the cog load applied to the points where the gears mesh with each other, and these vibrations generate noise. The size, direction and impact point of the tooth load can vary, and the tooth load is determined, for example, by the radius, torque and inertia of the gear wheel. Since the intermediate wheels are engaged with at least two toothed wheels / intermediate wheels and have at least two gear engagements, the intermediate wheels are doubly shocked by the toothed load. A gear mesh is defined as a direct connection / fastening between two toothed wheels / intermediate wheels. According to the present invention, by reducing the number of intermediate wheels used in the drive apparatus, gear engagement between the fuel pump and the combustion engine is minimized, and the fuel pump can be driven directly through the crankshaft of the combustion engine. As a result, the noise level is minimized, and a compact, space-saving fuel pump drive apparatus can be obtained.

By reducing the number of the toothed wheels / intermediate wheels coupled with the second toothed wheels disposed in the fuel pump, it is possible to obtain a fuel pump driving apparatus that is robust, has high wear resistance, is durable, and has a relatively long service life .

The fuel pump is preferably a separate unit mounted on the combustion engine. By using a separate fuel pump instead of the fuel pump incorporated in the combustion engine, service and maintenance of the fuel pump are facilitated. Similarly, since the fuel pump, the drive shaft of the fuel pump, and the second gear of the drive device are easy to disassemble and replace, servicing and maintenance of the drive device is facilitated. By using a separate / external fuel pump, a flexible and user-friendly fuel pump drive system can be obtained.

The driving shaft of the fuel pump in which the second gear is disposed and the crankshaft of the combustion engine in which the first gear is disposed are arranged parallel to each other.

Suitably, the drive according to the present invention can lower the noise of 3-6 dB from the gear transmission, compared to the prior art structure with intermediate wheels.

Preferably, the diameter of the first cog wheel is at least as large as the second cog wheel diameter. Alternatively, the first cog wheel is larger than the second cog wheel, which involves an up-shift. Preferably, the relationship between the first and second toothed wheels is such that the rotational speed of the second toothed wheel (gear on the fuel pump drive shaft) and the rotational speed of the first toothed wheel (the toothed wheel on the crankshaft) The speed ratio is 0.8-2, more preferably 1-2. When the diameters of the first and second toothed wheels are increased, the gap in the gear engagement (clearance of the herringbone teeth) and the tooth load applied on the toothed wheel are reduced. As a result, the fuel pump drive apparatus in which the noise level is minimized is obtained.

The play in the gear engagement, also called the angular backlash, is calculated according to the following equation.

Where x is the distance between two teeth and r is the radius of the cog wheel. Each backlash is preferably smaller than 0.5 degrees, and x is preferably smaller than 0.5 mm. The above equation shows that the larger the radius of the toothed wheel, the smaller each backlash and hence the lower the noise level. The large toothed wheels have large inertia and torque, which lowers the toothed load on the toothed wheels, thereby reducing the noise level.

Suitably, the diameter of the first cog wheel is 150-300 mm, preferably 200-260 mm, more preferably 240 mm.

Suitably, the diameter of the second cog wheel is 150-300 mm, preferably 200-260 mm, more preferably 240 mm.

Suitably, the flywheel is disposed adjacent to the first gear wheel at the crankshaft of the combustion engine. It is appropriate that the flywheel be disposed at the rear edge of the crankshaft. At the rear edge of the crankshaft, the flywheel is also connected to a gearbox, generator or pump in the vehicle. The second toothed wheel along the first toothed wheels is preferably disposed adjacent the flywheel at the rear edge of the crankshaft. The inertia of the flywheel is more flexible when the crankshaft is at the front edge than when it is at the rear edge of the flywheel. If the first gear is disposed in the stable region of the crankshaft, the risk of gear tooth load variation in engagement between the first and second gear wheels is reduced. Thus, when the first gear is disposed on the crankshaft adjacent the flywheel at the rear edge of the crankshaft, the noise level is lower than when the first gearwheel is disposed at the front edge of the crankshaft. The term adjacent means that when viewed along the direction in which the crankshaft extends, the second toothed wheel is disposed within a distance of up to about 800 mm from the flywheel.

Preferably, at least one intermediate wheel is disposed in association with the first gear wheel. It is also appropriate that one or more intermediate wheels are disposed in association with the third gear on the camshaft of the combustion engine. It is appropriate that the at least one intermediate wheel is arranged to be directly engaged with the first and third toothed wheels. In this way, the crankshaft of the combustion engine drives both the camshaft and the fuel pump of the combustion engine.

According to the present invention, the first cog wheel is disposed above the crankshaft of the combustion engine. Also preferably, the first intermediate wheel is arranged to be directly engaged with the first gear, so that the intermediate wheel is directly engaged with the second intermediate wheel. Suitably, the second intermediate wheel is arranged to be directly engaged with the third intermediate wheel, and the third intermediate wheel is directly engaged with the third and fourth toothed wheels. Preferably, the third gear is disposed on the first camshaft of the combustion engine, and the fourth gear is disposed on the second camshaft of the combustion engine. In this way, the crankshaft of the combustion engine drives both the fuel pump and both camshafts.

According to an aspect of the present invention, a second cog wheel disposed in the fuel pump is engaged only with the first cog wheel. By minimizing the number of gear meshing with the second gear disposed in the fuel pump, each amplitude and load in the gear engagement is minimized. As a result, the noise level is reduced.

The fuel pump connected to the combustion engine is preferably a high-pressure fuel pump.

According to an aspect of the invention, there is provided a drive for use in a fuel pump mounted to a combustion engine, wherein the combustion engine is preferably a diesel engine.

Other advantages of the present invention are described below in the examples of exemplary embodiments of the present invention.

1 is a schematic side view of a vehicle including a drive device used in a fuel pump mounted to a combustion engine according to an embodiment of the present invention.
2 is a view showing a fuel pump mounted on a combustion engine.
3A is a side view of a driving apparatus according to an embodiment of the present invention.
FIG. 3B is a view of the driving device according to FIG.
4 is a view schematically showing a driving apparatus according to an embodiment of the present invention.

Preferred embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which Fig.

1 is a schematic side view of a vehicle 1 including a drive device 2 for a fuel pump 20 according to the present invention connected to a combustion engine 4. Fig. A combustion engine 4 is connected to the gear box 8 and the gear box is connected to the drive wheels 10 of the vehicle 1 via a transmission. The vehicle also includes the chassis 12.

Fig. 2 shows a combustion engine 4 having a crankshaft 26. Fig. The fuel pump 20 is mounted to the combustion engine 4. [ The fuel pump is constituted by a separate unit mounted on the combustion engine 4. The fuel pump 20 is operated by the drive unit 2, which is described in detail in Figs. 3A and 3B.

Fig. 3A shows a driving apparatus 2 according to an embodiment of the present invention used for the fuel pump 20 mounted on the combustion engine 4. Fig. The fuel pump 20 is a high-pressure fuel pump that supplies fuel to cylinders (not shown) of the combustion engine in a high-pressure state. The combustion engine 4 includes a crankshaft 26 on which a first cog wheel 24 is disposed. A drive shaft 22 having a second gear wheel 34 is disposed in the fuel pump 20. The fuel pump 20 is disposed adjacent to the crankshaft 26 of the combustion engine 4. [ The crankshaft 26 extends parallel to the drive shaft 22 of the fuel pump 20. The crankshaft 26 has a forward end 28 and a rearward end 30 and a flywheel 32 is disposed at the rear end 30 thereof. A first gear wheel 24 is disposed adjacent to the flywheel 32 on the crankshaft 26. In this exemplary embodiment, the distance between the flywheel 32 and the first toothed wheel 24 is 600 mm when viewed in the direction of extension of the crankshaft 26. The first cog wheel 24 of the crankshaft 26 and the second cog wheel 34 of the drive shaft 22 of the fuel pump 20 are directly engaged and fastened to each other to engage the teeth of the first cog wheel 24 (Not shown) and the teeth (not shown) of the second cog wheel 34 are engaged with each other. In this way, the fuel pump 20 is directly driven by the crankshaft 26 of the combustion engine through the first gear 24. The number of gear meshes between the fuel pump 20 and the crankshaft 26 is minimized because of the reduced number of gear wheels of the drive system 2 so that the noise level is minimized . The greater the number of gear meshes, the more likely the gap will occur and the greater the impact due to the tooth load, ultimately resulting in noise. The inertia of the flywheel 32 entails making the rear end 30 of the crankshaft 26 more stable than the front end 28. By placing the first cog wheel 24 on the crankshaft 26 adjacent the flywheel 32, the engagement is stable and, as a result, the gear engagement is exposed to small load fluctuations, the first cog wheel 24 and the second toothed wheel 34 becomes small. As the load fluctuation becomes smaller, the vibration becomes smaller, so that the noise level caused by the drive device 2 is minimized. In addition, the first and second toothed wheels 24 and 34 have the same size and diameter. This means that the ratio between the rotational speed of the first toothed wheel and the rotational speed of the second toothed wheel is 1.0, that is, the gear ratio is 1: 1. In the present invention, since the size of the first cog wheel 24 is at least as large as the second cog wheel 34, the cog load is reduced and the gap in the gear engagement is minimized. Thus, the noise level generated by the drive device 2 is minimized. The smaller the number of large wheels, the more robust and durable structure is obtained. Figure 3a is an intermediate wheel directly coupled to the first toothed wheel 24 on the one hand and directly coupled to the third toothed wheel 38 of the camshaft 40 of the combustion engine 4 36). The camshaft 40 extends parallel to the crankshaft 26. Thus, the camshaft 40 is driven by the crankshaft 26 via the first toothed wheel 24 and the intermediate wheel 36.

Fig. 3B shows the driving device 2 according to Fig. 3A, which is viewed straight from behind the running direction of the vehicle 1. Fig.

4 schematically shows a drive system 2 for use in a fuel pump 20 according to an embodiment of the present invention. The drive unit 2 includes a first cog wheel 24 disposed on a crankshaft 26 (not shown) of the combustion engine 4, a drive shaft 22 (not shown) of the fuel pump 20 And a second cog wheel 34 disposed above the second cog wheel. The first toothed wheel 24 and the second toothed wheel 34 are arranged in direct engagement with each other. The first intermediate wheel 50 is arranged to engage with the first toothed wheel 24. And the second intermediate wheel 52 is disposed so as to engage with the first intermediate wheel 50 and the third intermediate wheel 54. Accordingly, the third intermediate wheel 54 is disposed on the third toothed wheel 56, which is ultimately disposed on the first camshaft (not shown), and on the second camshaft (not shown) And is also arranged to engage with the fourth toothed wheel 58.

The present invention should not be seen as limited to the exemplary embodiments described above. However, many modifications and combinations may be made within the scope of the appended claims. The number of intermediate wheels connected to the first gear may be arbitrary, for example. The first gear may be as large as the second gear, or it may be larger than the second gear, and the rotational speed of the second gear (the gear of the drive shaft of the fuel pump) and the rotational speed of the first gear The ratio between the rotational speeds of the gears (i.e., the gears on the gears) is 0.8-2, more preferably 1-2. To further reduce noise, flat bearings or other types of bearings may be disposed on the toothed wheels and / or the intermediate wheels. The fuel pump may be mounted on, for example, a diesel engine or an engine. The combustion engine may be a horizontal or vertical model. The vehicle in which the drive device is disposed may be a medium or large-sized vehicle such as a bus or a truck. The vehicle in which the drive device is disposed may be, for example, a boat.

Claims (10)

As the drive device 2 used in the fuel pump 20 mounted on the combustion engine 4,
A first cog wheel 24 disposed on the crankshaft 26 of the combustion engine 4 and a second cog wheel 34 disposed on the drive shaft 22 of the fuel pump 20, 26 and the drive shaft 22 are parallel to each other,
Characterized in that the first toothed wheel (24) and the second toothed wheel (34) are arranged in direct engagement with each other. The method according to claim 1,
Characterized in that the diameter of the first cog wheel (24) is at least as large as the diameter of the second cog wheel (34). 3. The method according to claim 1 or 2,
Characterized in that the diameter of the first cog wheel (24) is larger by the diameter of the second cog wheel (34). 4. The method according to any one of claims 1 to 3,
And the diameter of the second gear wheel (34) is 150-300 mm. 10. A method according to any one of the preceding claims,
Characterized in that the first gear wheel (24) disposed on the crankshaft (26) is adjacent to a flywheel (32) disposed on the crankshaft (26). 10. A method according to any one of the preceding claims,
Characterized in that the fuel pump (20) is mounted as a separate unit on the combustion engine (4). 10. A method according to any one of the preceding claims,
Wherein the fuel pump (20) is a high-pressure fuel pump. 10. A method according to any one of the preceding claims,
Characterized in that the toothed wheel (34) arranged in the fuel pump (20) is engaged only with the first toothed wheel (24). A combustion engine (4) comprising a drive device (2) according to any one of the preceding claims. A vehicle (1) comprising a combustion engine (4) according to claim 9.

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