阅读说明：本技术 排出气体再循环鼓风机和内燃发动机 (Exhaust gas recirculation blower and internal combustion engine ) 是由 S·罗斯特 S·迈尔 M·冯诺厄 M·施托克 P·施特法纳克 于 2020-08-21 设计创作，主要内容包括：一种内燃发动机的排出气体再循环鼓风机(8),具有鼓风机壳体(13),具有鼓风机轴(11),并且具有连接于鼓风机轴(11)的鼓风机叶轮(12),具有用于鼓风机轴(11)和鼓风机叶轮(11)的驱动器(9),其中驱动器(9)设计为液压马达。(An exhaust gas recirculation blower (8) of an internal combustion engine has a blower housing (13), has a blower shaft (11), and has a blower wheel (12) connected to the blower shaft (11), has a drive (9) for the blower shaft (11) and the blower wheel (11), wherein the drive (9) is designed as a hydraulic motor.)

1. An exhaust gas recirculation blower (8) of an internal combustion engine,

comprises a blower housing (13),

having a blower shaft (11) and a blower wheel (12) connected to the blower shaft (11),

having a drive (9) for the blower shaft (11) and the blower wheel (12),

it is characterized in that

The drive (9) is designed as a hydraulic motor.

2. Exhaust gas recirculation blower according to claim 1, characterized in that the blower shaft (11) is mounted in the blower housing (13) via at least one preferentially hydraulic axial bearing and at least one preferentially hydraulic radial bearing.

3. The exhaust gas recirculation blower according to claim 1 or claim 2, characterized in that the hydraulic motor (9) is indirectly coupled to the blower shaft (11) via a spur gear stage (14).

4. Exhaust gas recirculation blower according to claim 3, characterized in that the intermeshing gearwheel (15,16) of the spur gear stage (14) is of the longitudinal type and the blower shaft (11) is mounted in the blower housing (13) via a double-acting axial bearing (17) and at least one radial bearing (18).

5. Exhaust gas recirculation blower according to claim 3, characterized in that the intermeshing gearwheel (15,16) of the spur gear stage (15) is of the helical cut type and the blower shaft (11) is mounted in the blower housing (13) via at least one combined axial-radial bearing (20).

6. Exhaust gas recirculation blower according to claim 1 or claim 2, characterized in that the hydraulic motor (9) is directly coupled to the blower shaft (11).

7. An internal combustion engine (1), in particular a large internal combustion engine operating with heavy fuel oil or gas, such as an internal combustion engine of a ship,

having a plurality of cylinders (2), wherein gas exchange valves and/or fuel valves are actuatable by a hydraulic system (10) of the internal combustion engine,

having an exhaust-gas turbocharger (3), which exhaust-gas turbocharger (3) comprises a turbine (4) and a compressor (5), wherein in the turbine (4) the exhaust gas leaving the cylinder (2) is expandable and the energy extracted in the process can be used in the compressor (5) for compressing charge air to be supplied to the cylinder (2),

having an exhaust gas recirculation section (6), the exhaust gas recirculation section (6) comprising an exhaust gas recirculation blower (8),

it is characterized in that

The exhaust gas recirculation blower (8) is designed according to any one of claims 1 to 6, wherein the hydraulic motor (9) is coupled to the hydraulic system (10) of the internal combustion engine.

8. The internal combustion engine of claim 7, wherein the internal combustion engine is a large two-stroke internal combustion engine operating with heavy fuel oil or gas.

Technical Field

The invention relates to an exhaust gas recirculation blower and an internal combustion engine.

Background

Internal combustion engines having exhaust gas recirculation are familiar to those skilled in the art working to this end. In such internal combustion engines, it is known to draw exhaust gases (away from the internal combustion engine) from the exhaust branch of the internal combustion engine and to guide them in the direction of the charge air system of the internal combustion engine via a so-called exhaust gas recirculation blower (also referred to as EGR blower) of the exhaust gas recirculation and then to mix the exhaust gases with the charge air to be supplied to the cylinders of the internal combustion engine.

The exhaust gas recirculation blower or EGR blower is typically implemented as a turbo compressor, which compresses the exhaust gas to a defined pressure. An exhaust gas recirculation blower of an exhaust gas recirculation portion of an internal combustion engine includes a stator including a blower housing and a rotor including a blower shaft and a blower wheel. Here, the electric motor typically undertakes the drive of the blower shaft and the drive of the blower wheel of the exhaust gas recirculation blower (via the blower shaft).

Driving the blower shaft with the help of an electric motor requires a high frequency motor and a frequency converter for actuating the motor. The frequency converter is accommodated in a separate switchgear cabinet, wherein the frequency converter has to be cooled at high ambient temperatures. This results in considerable space requirements and cooling requirements. In the case of exceeding the reliable limit temperature of the frequency converter, the power of the electric motor and thus of the exhaust gas recirculation blower must be reduced.

If necessary, it is furthermore necessary to provide EMC shielding via elaborate measures. All together, making the use of an electric motor to drive the blower shaft of the exhaust gas recirculation blower problematic.

Starting from this, the invention is based on the object of creating a new type of exhaust gas recirculation blower and an internal combustion engine having such an exhaust gas recirculation blower.

Disclosure of Invention

This object is solved by an exhaust gas recirculation blower according to claim 1. Based on experience, the drive is designed as a hydraulic motor. With regard to the invention, it is proposed to use a hydraulic motor (also referred to as a hydroelectric motor) as a drive for the blower wheel of the blower shaft and thus for the exhaust gas recirculation blower. Through all of this, various advantages can be achieved compared to electric motors. Thus, no frequency converter is required, no cooling of the frequency converter is required, and no EMC shielding is required. By using a hydraulic motor or a hydro-electric motor as a drive for the blower shaft of the exhaust gas recirculation blower, a more compact, more robust and simpler design of the exhaust gas recirculation blower can be provided. Further, load performance, acceleration performance, and effectiveness can be improved.

According to an advantageous further development, the hydraulic motor is indirectly coupled to the blower shaft via a spur gear stage. Alternatively, the hydraulic motor is directly coupled to the blower shaft. The coupling of the hydraulic motor to the blower shaft via the spur gear stage is preferred in particular in the case of exhaust gas recirculation blowers rotating at relatively high rotational speeds. In case the exhaust gas recirculation blower is rotating at a relatively low rotational speed, it is advantageous to couple the hydraulic motor directly to the blower shaft.

In particular, when the hydraulic motor is indirectly coupled to the blower shaft via the spur gear stage, this is particularly advantageous when the mutually meshing gearwheel of the spur gear stage is of the spiral cut type. In this case, a part of the axial forces can then already be absorbed by the mounting of the hydraulic motor, so that a single axial bearing, which can be embodied particularly preferably as a combined axial-radial bearing together with the radial bearing of the blower shaft, is then sufficient in the region of the blower shaft for increasing the compactness.

An internal combustion engine having an exhaust gas recirculation blower is defined in claim 7.

Drawings

Preferred further developments of the invention emerge from the dependent claims and the following description. Exemplary embodiments of the present invention are explained in more detail via the drawings, without being limited thereto. Where the figures show:

FIG. 1 is a block diagram of an internal combustion engine having an exhaust gas recirculation portion and an exhaust gas recirculation blower;

FIG. 2 is a first embodiment of an exhaust gas recirculation blower according to the present disclosure;

FIG. 3 is a second embodiment of an exhaust gas recirculation blower according to the present invention; and

fig. 4 is a third embodiment of an exhaust gas recirculation blower according to the present invention.

Detailed Description

The present invention relates to an exhaust gas recirculation blower of an exhaust gas recirculation unit of an internal combustion engine.

Such exhaust gas recirculation blowers serve for conveying and compressing exhaust gases which are drawn off from the exhaust system of the internal combustion engine and are conveyed with the aid of the exhaust gas recirculation blower in the direction of the charge air system of the internal combustion engine. Furthermore, the invention relates to an internal combustion engine having an exhaust gas recirculation portion.

Fig. 1 shows a block diagram of an internal combustion engine 1 having a plurality of cylinders 2. During operation of the internal combustion engine 1, exhaust gases are generated which leave the cylinders 2 of the internal combustion engine 1 and are guided in the direction of the turbine 4 of the exhaust gas turbocharger 3 of the internal combustion engine 1. The exhaust gases leaving the cylinders 2 of the internal combustion engine 1 (guided via the turbine 4 of the exhaust gas turbocharger 3) are expanded in the turbine 4, wherein the energy extracted in the process is used to compress the charge air to be supplied to the cylinders 2 of the internal combustion engine 1 in the compressor 5 of the exhaust gas turbocharger 3.

The internal combustion engine 1 of fig. 1 includes an exhaust gas recirculation portion 6. The exhaust gas recirculation portion 6 includes an exhaust gas recirculation cooler 7 and an exhaust gas recirculation blower 8. The exhaust gas recirculation cooler 7 serves to cool the exhaust gas, which in fig. 1 is extracted at high pressure upstream of the turbine 4 from the exhaust system leading to the turbine 4. The exhaust gas recirculation blower 8 serves to convey the exhaust gas guided via the exhaust gas recirculation cooler 7 in the direction of the charge air system of the internal combustion engine in order to mix this exhaust gas of the exhaust gas recirculation with the compressed charge air downstream of the compressor 5.

The internal combustion engine 1 is in particular an internal combustion engine in which heavy fuel oil or gas is combusted, for example an internal combustion engine of a ship.

Such an internal combustion engine comprises gas exchange valves and fuel valves, not shown in the region of each cylinder 2, in order to supply the cylinders with fuel and charge air required for the combustion of the fuel in the cylinders 2 and, in addition, to discharge exhaust gases from the cylinders 2.

According to the invention, the exhaust gas recirculation blower 8 comprises a hydraulic motor 9 as a drive. The hydraulic motor 9 serves for driving a blower shaft of a rotor of an exhaust gas recirculation blower 8, which is not shown in detail in fig. 1, wherein the blower shaft supports a blower wheel, which is driven via the blower shaft. Details of the exhaust gas recirculation blower 8 are further described below with reference to the exemplary embodiment of fig. 2-4.

The hydraulic motor 9 of the exhaust gas recirculation blower 8 is also referred to as a hydro-electric motor, wherein such a hydraulic motor converts hydraulic energy into mechanical work. In order to supply the hydraulic motor 9 with hydraulic energy, the hydraulic motor 9 is coupled to a hydraulic system 10 of the internal combustion engine, wherein the hydraulic system 10 (in particular in a two-stroke internal combustion engine) is also used for hydraulic actuation of gas exchange valves and/or fuel valves of the cylinders 2 of the internal combustion engine 1. Thus, the hydraulic motor 9 can be easily connected to the existing hydraulic system 10 of the internal combustion engine 1 in order to supply hydraulic energy to the hydraulic motor 9 via the hydraulic system 10.

Fig. 2 shows a first exemplary embodiment of the exhaust gas recirculation blower 8 together with a hydraulic motor 9, wherein the hydraulic motor 9 is used for driving a blower shaft 11 of a rotor of the exhaust gas recirculation blower 8, wherein a blower wheel 12 is arranged on this blower shaft 11, the blower wheel 12 being used for compressing the exhaust gas which is conducted via the exhaust gas recirculation section 6. The blower shaft 11 and the blower wheel 12 are thus part of the rotor of the exhaust-gas recirculation blower 8, wherein the exhaust-gas recirculation blower 8 comprises, in addition to the rotor, a stator which comprises a blower housing 13.

In the illustrated exemplary embodiment of fig. 2, the hydraulic motor 9 is indirectly coupled to the blower shaft 11 via a spur gear stage 14 providing a transmission (gearing). The intermeshing gearwheels 15,16 of the spur gear stage 14 in fig. 2 are of the longitudinal type. The gearwheel 15 is located on the blower shaft 11 and the gearwheel 16 is located on the shaft 19 of the drive or hydraulic motor 9. In the exemplary embodiment of fig. 2 with the longitudinally cut, intermeshing gearwheel 15,16 of the spur gear stage 14, the blower shaft 11 is preferably mounted in the blower housing 13 via two axial and radial bearings. Here, an axial bearing is present for each force direction, i.e. both for the thrust direction and for the reverse thrust direction, which are provided in fig. 2 by a combined double-acting axial bearing 17. It is sufficient to provide the blower shaft 11 with a single radial bearing 18, so-called cantilever-mounted. However, there may also be two radial bearings. For reasons of installation space, the two axial bearings are provided by a common double-acting axial bearing 17. Two separate axial bearings may also be used. The axial bearing and the radial bearing are preferably hydraulic bearings.

Fig. 3 shows a modification of the exemplary embodiment of fig. 2, in which the intermeshing gearwheel 15,16 of the spur gear stage 14 is of the helical cut type. Here, the axial force in the counter-thrust direction may then have been absorbed by the hydraulic motor 9. In this case, it then suffices to provide a single axial bearing and a single radial bearing in the region of the blower shaft 11, which are then preferably embodied as a combined axial-radial bearing 20, in order to provide a particularly compact design. However, it is also possible to embody the axial bearing and the radial bearing as separate components. Preferably, the fluid bearing is re-used. In fig. 3, a further radial bearing 21 for the blower shaft 11 is shown in addition to the combined axial-radial bearing 20.

The mounting of the blower shaft 11 and the shaft 19 of the hydraulic motor 9 is preferably realized jointly in the blower housing 13, the blower housing 13 acting as a bearing housing. This is preferred in order to provide a compact design on the one hand.

Fig. 4 shows an embodiment of the exhaust gas recirculation blower 8 (in case the hydraulic motor 9 is directly coupled to the blower shaft 11). While the embodiment of fig. 2 and 3 is particularly suitable with respect to a high speed exhaust gas recirculation blower, the embodiment of fig. 4 is suitable for a relatively low speed exhaust gas recirculation blower 8.

The mounting of the blower shaft 11 is then effected via the axial bearings 22,23 and the radial bearings 24,25 (i.e. preferably in a hydraulic embodiment), the hydraulic motor 9 then being coupled directly to the blower shaft 11. The bearing may be implemented as a combined radial and axial bearing.

As already explained, the exhaust gas recirculation blower 8 according to the invention is preferably used on internal combustion engines operated with heavy fuel oil or gas, as for example in connection with large two-stroke internal combustion engines, in particular marine two-stroke internal combustion engines.

Parts list

1 internal combustion engine

2 cylinder

3 exhaust gas turbocharger

4 turbine

5 compressor

6 exhaust gas recirculation part

7 exhaust gas recirculation cooler

8 exhaust gas recirculation blower

9 driver/hydraulic motor

10 hydraulic system

11 blower shaft

12 blower impeller

13 blower casing

14 spur gear stage

15 big gear

16 big gear

17 axial bearing

18 radial bearing

19 shaft

20 axial/radial bearing

21 radial bearing

22 axial bearing

23 axial bearing

24 radial bearing

25 radial bearings.