COMPRESSOR FOR A CHARGING DEVICE OF AN INTERNAL COMBUSTION ENGINE, AND CHARGING DEVICE FOR AN INTERNAL COMBUSTION ENGINE

Abstract

A compressor for a charging device of an internal combustion engine has a compressor impeller arranged for conjoint rotation on a rotor shaft. An air supply channel conducts an air mass flow to the compressor impeller. An iris diaphragm mechanism is upstream of the compressor impeller and has multiple lamellae to close or to open a diaphragm aperture to vary a flow cross section for the air mass flow for flow against the compressor impeller. A housing at least partially delimits the air supply channel. The iris diaphragm mechanism is located in the housing. An actuator is mechanically coupled to the iris diaphragm mechanism via an opening in the housing for the purpose of actuating the iris diaphragm mechanism, wherein the actuator is arranged on the housing such that the opening is closed off by the actuator.

Claims

1. A compressor for a charging device of an internal combustion engine comprising: a compressor impeller arranged for conjoint rotation on a rotor shaft; an air supply channel for conducting an air mass flow to the compressor impeller; a housing which at least partially delimits the air supply channel; an iris diaphragm mechanism located in the housing and upstream of the compressor impeller; a plurality of lamellae to close and open a diaphragm aperture, such that variable setting of a flow cross section for the air mass flow for flow against the compressor impeller; and an actuator mechanically coupled to the iris diaphragm mechanism via an opening in the housing, wherein the actuator is arranged on the housing such that the opening is a sealed-off by the actuator.

2. The compressor as claimed in claim 1, wherein the actuator is a cover for the opening of the housing.

3. The compressor as claimed in claim 1, wherein the actuator is fixed on the housing from the outside with a flat bottom side to cover the opening.

4. The compressor as claimed in claim 1, wherein a sealing material lines the opening and is arranged between the actuator and the housing.

5. The compressor as claimed in claim 4, wherein one of the housing and the actuator has a groove which surrounds the opening and in which the sealing material is arranged.

6. The compressor as claimed in claim 1, wherein the actuator is arranged within the housing via a coupling mechanism and mechanically coupled to an adjusting ring of the iris diaphragm mechanism for closing and opening the diaphragm aperture.

7. The compressor as claimed in claim 1, wherein the housing is one of single-part and multi-part form.

8. The compressor as claimed in claim 7, wherein the housing is of two-part form, wherein a first part of the housing is a part of a compressor housing and a second part is a housing cover connected to the first part.

9. The compressor as claimed in claim 1, wherein the housing is formed as part of a compressor housing.

10. The compressor as claimed in claim 1, wherein the housing is a separate part from a compressor housing and is fixed on the compressor housing.

11. A charging device for an internal combustion engine, comprising: a rotor shaft is rotatably mounted in a rotor bearing; a compressor having a compressor impeller arranged for conjoint rotation on a rotor shaft, an air supply channel for conducting an air mass flow to the compressor impeller, a housing which at least partially delimits the air supply channel, an iris diaphragm mechanism located in the housing and upstream of the compressor impeller, a plurality of lamellae to close and open a diaphragm aperture, such that variable setting of a flow cross section for the air mass flow for flow against the compressor impeller; and an actuator mechanically coupled to the iris diaphragm mechanism via an opening in the housing, wherein the actuator is arranged on the housing such that the opening is a sealed-off by the actuator; and wherein the charging device is one of an exhaust-gas turbocharger, an electromotively operated charger, and as a charger operated via a mechanical coupling to the internal combustion engine.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0040] FIG. 1 shows a schematic sectional view of a charging device with a compressor with an iris diaphragm mechanism;

[0041] FIGS. 2A to 2C show schematic plan views of the iris diaphragm mechanism in three different states;

[0042] FIG. 3 shows a schematic cross-sectional view of a compressor with an iris diaphragm mechanism; and

[0043] FIG. 4 shows a schematic cross-sectional view of a compressor with an iris diaphragm mechanism as per an exemplary embodiment of the invention.

DETAILED DESCRIPTION

[0044] An exemplary embodiment will be described below with the aid of the appended figures. Identical elements or elements of identical action are provided with the same reference signs throughout the figures.

[0045] FIG. 1 schematically shows, in a sectional illustration, an example of a charging device 1, which comprises a compressor 30 (a radial compressor in this case), a rotor bearing 40 and a drive unit 20. The compressor 30 has an optional overrun air recirculation valve (not illustrated), and an air mass flow LM is also indicated by arrows. A so-called charger rotor 10 of the charging device 1 has a compressor impeller 13 (also referred to as compressor wheel) and a rotor shaft 14 (also referred to as shaft). The charger rotor 10 rotates about a rotor axis of rotation 15 of the rotor shaft 14 during operation. The rotor axis of rotation 15 and at the same time the charger axis 2 (also referred to as longitudinal axis) are illustrated by the indicated center line and identify the axial orientation of the exhaust-gas charging device 1. Here, the charger rotor 10 is supported in a bearing housing 41 with its rotor shaft 14 by means of two radial bearings 42 and one axial bearing disk 43. Both the radial bearings 42 and the axial bearing disk 43 are supplied with lubricant via oil supply channels 44 of an oil connection 45.

[0046] In this example, a charging device 1, as illustrated in FIG. 1, has a multi-part construction. Here, a housing of the drive unit 20, a compressor housing 31 which is able to be arranged in the intake tract of the internal combustion engine, and a rotor bearing 40 which is provided between the housing of the drive unit 20 and the compressor housing 31 are arranged next to one another with respect to the common charger axis 2 and are connected together in terms of assembly, wherein alternative arrangements and configurations of drive units and rotor bearings are also possible.

[0047] The charger rotor 10 constitutes a further structural unit of the charging device 1 and has at least the rotor shaft 14 and the compressor impeller 13, which compressor impeller is arranged in the compressor housing 31 and has an impeller blade arrangement 131. The compressor impeller 13 is arranged at one end of the rotor shaft 14 and is connected rotationally conjointly to the latter. The rotor shaft 14 extends in the direction of the charger axis 2 axially through the bearing housing 41 and is provided therein with rotary support in the axial and radial directions about its longitudinal axis, the rotor axis of rotation 15, wherein the rotor axis of rotation 15 lies in the turbocharger axis 2, i.e. coincides therewith.

[0048] The compressor housing 31 has an air supply channel 36, which optionally has an intake pipe connector piece 37 for connection to the air intake system (not illustrated) of the internal combustion engine and runs in the direction of the charger axis 2 toward the axial end of the compressor impeller 13. Via this air supply channel 36, the air mass flow LM is drawn in from the air intake system by the compressor impeller 13 and conducted to the compressor impeller 13. The air supply channel 36 may also be part of an intake connector and thus not part of the compressor housing 31. The air supply channel 36 adjoins for example the compressor housing 31 and forms a compressor inlet 36a for the conducting of the air mass flow LM to the compressor impeller 13.

[0049] Furthermore, the compressor housing 31 generally has a ring-shaped channel which is arranged in a ring-shaped manner around the charger axis 2 and the compressor impeller 13 and which widens in a spiral-shaped manner away from the compressor impeller 13, and which is referred to as a spiral channel 32. Said spiral channel 32 has a gap opening which runs at least over a part of the inner circumference and which has a defined gap width, the so-called diffuser 35, which, directed in a radial direction away from the outer circumference of the compressor impeller 13, runs into the spiral channel 32 and through which the air mass flow LM flows away from the compressor impeller 13 at elevated pressure into the spiral channel 32.

[0050] The spiral channel 32 furthermore has a tangentially outwardly directed air discharge channel 33 with an optional manifold connector piece 34 for connection to an air manifold (not illustrated) of an internal combustion engine. Through the air discharge channel 33, the air mass flow LM is conducted at elevated pressure into the air manifold of the internal combustion engine.

[0051] In FIG. 1, the drive unit 20 is not shown in any more detail and may be embodied either as an exhaust-gas turbine or as an electromotive drive unit or else as a means for mechanically coupling to the internal combustion engine, for example as an intermediate transmission which is operatively connected to a rotating shaft of the internal combustion engine, this making the charging device 1 an exhaust-gas turbocharger in the one case and an electromotively operated charger, also referred to as an E booster or E compressor, or a mechanical charger in the other case. In the case of an exhaust-gas turbocharger, provision would be made opposite the compressor impeller 13 for example of a turbine impeller (also referred to as a turbine wheel), which would likewise be arranged for conjoint rotation on the rotor shaft 14 and be driven by an exhaust-gas mass flow.

[0052] Upstream of the compressor impeller 13 in the air mass flow LM, an iris diaphragm mechanism 50 is, in addition to or as an alternative to an overrun air recirculation valve (see FIG. 1), arranged in the air supply channel 36 immediately in front of a compressor inlet 36a (also compressor entry), and/or forms at least one sub-region of the air supply channel 36 immediately in front of the compressor inlet 36a of the compressor housing 31. With regard to its functional principle, the iris diaphragm mechanism 50 is similar to an iris diaphragm in a camera. The iris diaphragm mechanism 50 is designed to at least partially close or open a diaphragm aperture such that variable setting of a flow cross section for the air mass flow LM, for flow against the compressor impeller 13, is possible, at least over a sub-region of the flow cross section. The iris diaphragm mechanism 50 allows a characteristic map shift for the compressor 30 in that it acts as a variable inlet throttle for the compressor impeller 13.

[0053] FIGS. 2A to 2C schematically show the iris diaphragm mechanism 50 of the charging device 1 in three different operating states. The iris diaphragm mechanism 50 is fixed on or in the compressor housing 31 and/or at least partially forms the latter. Alternatively, the iris diaphragm mechanism 50 is mounted on a separate, fixed housing for the iris diaphragm mechanism 50. Alternatively, the iris diaphragm mechanism 50 is mounted on or in a multi-part housing, wherein a part of the multi-part housing is formed by the compressor housing 31 and a part is formed by an additional, separate housing (element).

[0054] The iris diaphragm mechanism 50 has a bearing ring 68 which is fixed in the air supply channel 36 so as to be concentric with the compressor inlet 36a, an adjusting ring 53 which is arranged so as to be concentric with said bearing ring and is rotatable about a common center and has an adjusting lever 53a, and a plurality of lamellae 52 which are mounted so as to be rotatable about a respective center of rotation in the bearing ring 68. Instead of the bearing ring 68, the compressor housing 31 or another housing (element) may also serve as a bearing. The lamellae 52 have for example a plate-like lamella main body and at least one pin-like actuating element (not visible here), which is designed for actuating the respective lamella 52, as integral contituent parts of the respective lamella 52.

[0055] The lamellae 52 are also rotatable and/or displaceable on the adjusting ring 53, for example by means of the actuating element. In the example, the adjusting ring 53 has three grooves (indicated in the figures) for the mounting/guiding of the lamellae 52. The lamellae 52 are synchronized and moved via the adjusting ring 53. The adjusting ring 53 is mounted for example on or in the housing. By actuation of the adjusting ring 53, the lamellae 52 are pivoted radially inward and narrow a diaphragm aperture 55 of the iris diaphragm mechanism 50. Here, FIG. 2A shows the diaphragm aperture 55 with a maximum opening width (open position), FIG. 2B shows the diaphragm aperture 55 with a reduced opening width, and FIG. 2C shows the diaphragm aperture 55 with a minimum opening width (closed position).

[0056] FIG. 3 shows, in a schematic side (transverse) view, a compressor 30 with an iris diaphragm mechanism 50. The iris diaphragm mechanism 50 is illustrated with the adjusting ring 53 and lamellae 52, which delimit the diaphragm aperture 55. The iris diaphragm mechanism 50 is mounted between the compressor housing 31 and a further housing element 31, which is connected to the compressor housing 31. An actuator 56 having an actuator shaft 57 is mounted on the compressor housing 31. A coupling bar 58 is attached rotationally conjointly to the actuator shaft 57 and is in turn itself connected to the adjusting ring 53, for example to the aforementioned adjusting lever, by way of a coupling pin 59. In this way, by actuation of the actuator 56 and rotation of the actuator shaft 57, it is possible to adjust the adjusting ring 53 and thus, as mentioned at the beginning, the lamellae 52.

[0057] In the embodiment described, the actuator 56 is attached to the compressor housing 31, which entails a generally long and elaborate coupling mechanism 65 for actuating the iris diaphragm mechanism 50. The coupling mechanism 65 is formed by the coupling bar 58 and by the coupling pin 59. The coupling mechanism 65 may also comprise further elements which are provided for the coupling of the actuator 56 to the adjusting ring 53 or be of a quite different construction. Furthermore, the coupling mechanism 65 and a part of the adjusting ring 53 are exposed toward the outside. Consequently, these parts can be soiled and, as a result, the mobility of the iris diaphragm mechanism 50 can be impaired. In the worst case, even failure of the function of the iris diaphragm mechanism 50 occurs.

[0058] It is pointed out at this juncture that FIG. 3, like FIG. 4 described below, involves illustrations which are not true to scale and are merely schematic. In this regard, for example in FIG. 3, the actuator is illustrated merely as a rounded rectangle, which gives the impression that this is of flat form. In practice, however, the actuators, and in particular the housings thereof, are generally of varied shape.

[0059] FIG. 4 shows, in a schematic side view, a compressor 30 as per an exemplary embodiment. Analogously to above, an actuator 56 having an actuator shaft 57 is shown. A coupling bar 58 is in turn attached rotationally conjointly to the actuator shaft 57 and is itself attached to the adjusting ring 53 by means of the coupling pin 59. By contrast to the previous example, the iris diaphragm mechanism 50 and the coupling mechanism 65, consisting of the coupling bar 58 and the coupling pin 59, are arranged within a housing 60 of the compressor 30.

[0060] In other words, the aforementioned elements are integrated into the housing 60. The housing 60 is for example the compressor housing 31 (see FIGS. 1 and 3). However, it may also be a separate housing, or a two-part housing consisting of the compressor housing and an additional housing element or cover. The housing 60 at least partially delimits the air supply channel 36. The housing 60 has outwardly toward the surroundings an opening 63 via which the actuator 56 is mechanically coupled to the iris diaphragm mechanism 50 for the purpose of actuating the latter.

[0061] In the shown exemplary embodiment as per FIG. 4, the actuator 56 acts as a cover for the housing 60 and closes off the opening 63 in a sealing manner. For this purpose, the housing 60 has, so as to surround the opening 63, a groove 62 in which sealing material 61 is arranged. Alternatively, the groove 62 and the sealing material 62 are arranged in the actuator 56 itself. By contrast to the embodiment as per FIG. 3, in the exemplary embodiment in FIG. 4, the bottom side 64 of the actuator 56 is of flat form and covers the opening 63 completely, with the result that the covering function is achieved.

[0062] The actuator 56 itself serves as a seal. At the same time, by contrast to the embodiment as per FIG. 3, the coupling mechanism 65 itself is integrated into the housing 60. It is thus not necessary for moving parts to be sealed off with respect to the surroundings. The flow-guiding components of the compressor 30, in particular the air supply channel 36, are thus sealed off with respect to the surroundings on the compressor side.

[0063] It should be pointed out at this juncture that the compressor 30 described does not necessarily have to be part of the charging device 1 described by way of example in FIG. 1. Rather, the charging device 1 may also be configured differently.

[0064] The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the scope of the following claims.