DE102009003244A1 - charging - Google Patents

Abstract

A charging device includes: a rotating shaft (11) driven by exhaust gas; a middle housing (12) rotatably supporting the rotary shaft (11); a compressor wheel (13) that rotates integrally with the rotary shaft (11); and a compressor housing (14) forming an inlet passage (15) having a diffuser portion (15b) around the compressor wheel (13), wherein a wall surface member (21) is provided which forms a wall surface of the inlet passage (15) in the diffuser portion (15b). A body portion (22) is provided so as to support the wall surface member (21). The wall surface member (21) forms the wall surface at which the activation energy of an oxidation reaction in which the oil components adhering to the wall surface are converted to high molecular weight products is higher than the activation energy required for the oxidation reaction on the wall surfaces. which are formed of the same material as the body portion (22).

Description

Background of the invention

1. Field of the invention

The The present invention relates to a charging device, and more particularly to a turbocharger for an internal combustion engine.

2. Description of the associated State of the art

turbocharger for an internal combustion engine generally have a Turbine on by the energy of the engine emitted exhaust gas is rotated to rotate a compressor wheel, which is directly coupled with the turbine to supply air to the internal combustion engine to charge. Accordingly, when at high Speed of high speed rotating compressor wheel charged air in a diffuser section with a small distance from wall to wall, reducing their speed is the temperature of the diffuser section as a result of adiabatic change (adiabatic change, in which the speed energy of the air is converted into pressure is increased) or for other reasons.

In Internal combustion engines occur so-called blow-by gases (blow-by gases), an unburned air-fuel mixture and burned gas included, from the combustion chamber into an upper section of the crankcase through the space between the Cylinder and the piston off. Thus, internal combustion engines are a gas return system with blow-by gas with overpressure crankcase ventilation (PCV = positive crankcase ventilation), which is the crankcase vented to deteriorate the engine oil in the internal combustion engine to prevent, and the blow-by gases in the Crank cases become to some extent a gas-liquid separation exposed by an oil separator and then return to the inlet pipe back.

Even though the gas entering the inlet pipe through the return system for the blow-by gas returns (below this termed "PCV gas"), in a certain way Grade has undergone a gas-liquid separation can the PCV still vaporized engine oil, unburned fuel components and the like (hereinafter collectively referred to as "oil components"), these oil components are generally disadvantageous Have an effect on the turbocharger and avoid such effects should be.

For example Be the oil components that adhere to the wall surfaces attached to the outlet side of the diffuser section the flow velocity of the air in the compressor the turbocharger is oxidized and oxidized into products with high Molecular weight called sludge by a condensation polymerization transformed. The accumulated mud is also one thermal deterioration and carbonization exposed what can cause coking and thereby the performance of the Can reduce compressor. In addition, the Sulfur components contained in the oil a so-called black corrosion (black corrosion) and the like at the bearings under high temperature cause.

In a charging device used in the Japanese Patent Application Publication No. 2005-180362 ( JP-A-2005-180362 ), for example, the temperature of the air discharged from the supercharger of the turbocharger is detected and compared with an upper limit temperature set at a temperature lower than the temperature at which coking occurs (coking temperature). and the supercharging pressure is reduced to lower the temperature of the discharged air to a temperature lower than the coking temperature when the detected temperature of the discharged air exceeds the upper limit temperature.

A supercharger employing turbocharger bearings made of a copper alloy containing Mn-Si compound dispersed therein to prevent so-called black corrosion caused by sulfur components in the oil in a high-temperature environment and abnormal wear lead the camp is in the Japanese Patent Application Publication No. 2003-42145 ( JP-A-2003-42 145 ) and in the Japanese Patent Application Publication No. 61-117 240 ( JP-A-61-117 240 ).

In addition, a supercharger in which the outer periphery of the discharge-side portion of the compressor wheel (impeller) is formed of a material superior in high-temperature strength, such as a high-Cu and Si-containing aluminum alloy, in Japanese Patent Application Publication No. 2000-291441 ( JP-A-2000-291 441 ).

In the above-described charging devices, however, especially under the wall surfaces in the channel of the diffuser portion, the oil components may be adhered to the wall surface on the side of the middle case supporting the rotating shaft of the compressor wheel. In addition, since the temperature of the wall surface at the side of the center housing becomes very high due to the heat from the turbine wheel and the bearings subjected to a very high temperature, it also transfers to the wall surface, deterioration of efficiency (of performance) ) of the compressor, which is caused by the oil coking in the diffuser section with a slight distance from wall to wall, can not be completely eliminated.

Especially when the internal combustion engine at a high speed and a high Load condition is working, since the supercharging pressure is high and the Temperature of the inlet air into the diffuser section is very high, in ever increasing measure the mud on the wall surface accumulated near the middle housing in the diffuser section, and the flow channel in the diffuser section is narrowed, resulting in a deterioration of the pressure conversion efficiency in the Diffuser section and increased tendency to oil coking leads.

Although controlling the supercharging pressure based on the compressor outlet temperature, as described in the document JP-A-2005-180362 is effective to solve this problem, it requires a device structure in that a function is added, which not only increases the cost but also affects the improvement of the performance of the internal combustion engine, since the operating conditions of the turbocharger by the supercharging pressure and the compressor utilization temperature is limited.

Summary of the invention

The The present invention provides a charging device under low Cost at which the deterioration of compressor efficiency, the caused by oil coking can be prevented by preventing the oil reaching the diffuser section is converted into mud.

One first aspect of the present invention relates to a charging device, comprising: a rotary shaft which is rotated by the energy of the Exhaust gas is driven in rotation, a middle housing, which rotatably supports the rotary shaft, a compressor wheel that is supported by the rotary shaft and integrally rotates with the rotary shaft, and a compressor housing, the Coupled with the middle housing is the compressor wheel accommodate, and that forms an inlet duct, the one Diffuser section around the compressor wheel around. At least a housing, d. H. the middle case or the Compressor housing has a wall surface element, the one wall surface of the intake passage in the diffuser section forms and a body portion which supports the wall surface element. The wall surface element forms the wall surface, at which the activation energy for the reaction in which the oil components that adhere to the wall surface in the diffuser section, in high-end products Molecular weight is greater than the activation energy for the reaction of the oil components is that has adhered to the wall surfaces, which are formed from the material of the body portion.

If oil components, contained in the PCV gas, that to the inlet side and the like are returned to the wall surface adhered by the wall panel in the diffuser section is formed, should, when the temperature of the wall surface increases, the reaction rate with which the attached oil components in high molecular weight products due to oxidation and Condensation be converted, increase. however is according to the above-explained Aspect the rate of reaction at which the attached oil components into the high molecular weight products due to oxidation and condensation polymerization are converted by the catalytic contact effect the wall surface which acts as an inhibitor (as a Inhibiting or preventing means), and the activation energy for the reaction in which the oil components, which have adhered to the wall surface, in the Products with high molecular weight are converted to higher. Therefore, the reaction in which the oil is converted into sludge is prevented, and accumulating the thermally deteriorated and carbonized sludge in the diffuser section is prevented. In addition, there is no need for a construction in which the supercharging pressure is controlled on the basis of the compressor outlet temperature will be reduced, the costs, and the operating conditions of the turbocharger are not affected by the supercharging pressure and the compressor outlet temperature limited.

According to the As explained above, the entire wall surface area the wall surface element in a uniform manner the function of increasing the activation energy in comparison to meet the wall surfaces made of the material of the body portion are formed.

at The above-explained aspect, the wall surface element be made of a material that has a higher thermal Conductivity as the body section has.

According to the aspect explained above, a uniform temperature distribution becomes over generates the wall surface formed on the wall surface member in the diffuser portion, and no locally high temperature region is formed thereon. Therefore, mud is unlikely to form on the wall surface.

In The above-explained aspect, the wall surface element a metal plate-like member having the wall surface on the side of the middle housing in the diffuser section formed. In this case, the wall surface element a uniform thickness and a smooth surface to have.

According to the The above explained aspect is the transformation of the attached oil effectively prevented in sludge and becomes an oil-coking prevented in the area where the oil tends to adhere.

In The above-explained aspect, the wall surface element in the body portion of the middle housing so sit and be embedded that the wall surface is exposed in the diffuser section.

In The above-explained aspect, the scope and the Side opposite to the wall surface of the wall surface element is, with the body portion of the middle housing be connected by soldering.

In The above-explained aspect, the wall surface element a uniform thickness and a smooth surface to have.

In In the above aspect, the wall surface forming member a metal film which is integral with the body portion is connected to the wall surface on the side of the middle Form housing in the diffuser section.

According to the The above explained aspect is the transformation of the attached oil effectively prevented in sludge, and an oil-coking is prevented in the area where the oil tends to to pin.

In The above-explained aspect, the wall surface element with the body portion of the middle housing be connected so that the wall surface in the diffuser section is exposed.

In The above-explained aspect, the wall surface element in a space between the compressor wheel and the body portion extend.

In The above-explained aspect, the wall surface element have a ring-like shape and can surround the compressor wheel.

According to the explained above aspect, since the wall surface element almost the entire wall surface on the side of the middle Housing covered at the diffuser section, converting of tacked oil effectively prevented in sludge, and An oil-coking is done in a reliable way prevents the area where the oil tends to get to adhere.

In The above-explained aspect, the wall surface element be made of such a material that the wall surface is oxidized by the heat that is generated when the energy the air discharged from the compressor wheel at a high speed and is converted into a high pressure, simultaneously with the heat that is transferred from the exhaust gas and is reduced by the oil components that are attached to the wall surface.

In The above-explained aspect, the wall surface element mainly composed of copper.

According to the explained above, it is possible to produce the wall surface element cost and to allow it to fully function to prevent the reaction by which the oil components be converted into mud.

In The above-explained aspect, the wall surface element have a surface layer portion whose activation energy higher than that of the wall surface that is out the material of the body portion is formed and forming the wall surface in the diffuser section; and it may have a base layer section made of a material is formed, which has a higher thermal conductivity as the surface layer portion has.

According to the the aspect explained above becomes the ability the wall surface in the diffuser portion for preventing the reaction that forms mud, and a heightened Thermal conductivity prevents localized temperature rise the wall surface. Therefore, converting the attached oil can be effectively prevented in sludge, and an oil-coking can be avoided.

In the aspect explained above, the surface layer portion may be elastically penetrated by the base layer portion of the wall surface member supports his. According to this structure, an effect for reducing the pulsations of the compressor discharge pressure, which typically occurs at a frequency of a few kilohertz, can be achieved.

In The above-explained aspect may be a variety of Resonance cavities that the airflow noise Decrease that by the compressor during operation is generated behind the wall surface element (in at least a housing) are formed.

According to the present invention, since the surface energy for the reaction in which the attached oil components be converted into high molecular weight products, higher is, and the reaction in which the oil is converted into sludge is prevented on the wall surface coming out of the Wall surface element in the diffuser section consists. Thereby a charging device can be created at a low cost, at the deterioration caused by oil coking the compressor efficiency (capacity of the compressor) can be prevented by preventing the reaction the oil that adheres to the diffuser section has, is converted into mud.

Brief description of the drawings

The set out above and other objectives, features and benefits The present invention will be understood from the below Description of the embodiments with reference to the accompanying drawings clearly show in which the same Reference numerals represent like elements.

1 shows a cross-sectional view of an essential portion of a charging device according to a first embodiment of the present invention.

2 shows a cross-sectional view of an essential portion of a charging device according to a second embodiment of the present invention.

3 shows a cross-sectional view of a wall surface element of a charging device according to a third embodiment of the present invention.

Detailed description the embodiments

The Embodiments of the present invention are below described with reference to the drawings.

1 FIG. 12 is a cross-sectional view of the general structure of a charging device according to a first embodiment of the present invention, and illustrates an example in which the present invention is applied to a turbocharger of an internal combustion engine for a motor vehicle.

Like this in 1 is shown, the charging device according to this embodiment (the entirety is not shown), a rotary shaft 11 , a middle case 12 that rotatably rotates the shaft 11 supports, a compressor wheel 13 that through the rotary shaft 11 is supported and together with the rotary shaft 11 turns, and a compressor housing 14 on, with the middle case 12 is coupled to the compressor wheel 13 to accommodate, and that an inlet channel 15 formed.

The rotary shaft 11 is with a turbine wheel in an exhaust duct (not shown) at its right end side in FIG 1 coupled, and the rotary shaft 11 rotates together with the turbine wheel when the turbine wheel is driven in rotation by the energy of the exhaust gas.

The middle case 12 is coupled to a turbine housing which houses the turbine wheel at its right end side 1 is made of, for example, cast iron or a cast iron alloy. Although the details are not shown, a plurality of bearings are rotatably the rotary shaft 11 support, a snap ring, which is the rotary shaft 11 positioned in the axial direction, and the like at the center of the middle housing 12 attached. A seal 16 that closes the shaft hole is on the opposite side of the compressor wheel 13 attached, and a labyrinth seal is between the seal 16 and the middle housing 12 formed (the components on the side of the middle housing 12 are not shown). The middle case 12 and the turbine housing are coupled to and supported by an exhaust manifold (not shown).

The compressor housing 14 forms an inlet channel 15 , which is a part of the intake passage of an internal combustion engine (not shown), and is made of, for example, an aluminum alloy.

The inlet channel 15 has an upstream section 15a looking to the left end side under consideration of 1 at the center of the compressor housing 14 is open and connected to an air cleaning device (not shown) and sucks in air through the air cleaner.

The inlet channel 15 curves radially outward from the center of the compressor housing 14 through the compressor wheel 13 immediately downstream of the upstream section 15a is, and has a diffuser section 15b , the compressor wheel 13 surrounds and forms a narrow annular plate-like channel, which is generally perpendicular to the rotary shaft 11 extends.

Besides, the inlet channel has 15 a spiral-like downstream portion 15c connected to the outer periphery of the diffuser section 15b is connected, and is at the downstream end of the downstream portion 15c with an intake passage (not shown) located on the side of the intake port of the internal combustion engine to which a throttle valve and the like are arranged, via an intercooler.

The compressor wheel 13 has a variety of wings 13a (Compressor blades) which are arranged at regular angular intervals to form a centrifugal compressor, and the air from the upstream section 15a of the intake channel 15 which can compress air and high velocity airflow into the diffuser section 15b can deliver when they get together with the rotary shaft 11 rotate. Although the distance between the left and the right wall of the diffuser section 15b who in 1 is shown, in reality is small, the distance is in 1 exaggerated for the sake of illustration. The of the compressor wheel 13 discharged air flows radially outward and reduces its velocity in the diffuser section 15b wherein the pressure of the intake air in the downstream section 15c is increased.

At least the middle case 12 or the compressor housing 14 has a wall surface element 21 that in the diffuser section 15b of the intake channel 15 is arranged, and a body portion 22 on top of the wall surface element 21 supports.

The wall surface element 21 forms a wall surface 21a of the middle housing 12 in the diffuser section 15b out. The wall surface 21a has a greater ability to prevent the conversion of the oil components that have adhered to the wall surface into sludge (conversion of oil components into high molecular weight products) due to the oxidation and condensation polymerization than those of the wall surfaces that are downstream and upstream of the diffuser section 15b are made of the material of the body section 22 are formed.

More specifically, the wall panel is 21 made of a material such as copper having a higher activation energy (J / mol) for the oxidation reaction of the oil components, which converts the oil components into the high molecular weight products, and a higher thermal conductivity (E / (m · k)) ) has as the material of the body section 22 which can be made of cast iron. The wall surface element 21 For example, it is made of a copper plate roller (copper plate) (metal-like plate-like member) having a smooth surface and a uniform thickness, and is seated in the wall surface on the side of the middle housing 12 in the diffuser section 15b , the compressor wheel 13 surrounds, and is embedded there. The wall surface 21a of the wall surface element 21 is exposed and the circumference of the wall surface element 21 and its back are with the body section 22 of the middle housing 12 for example, connected by soldering. The wall surface element 21 shows a catalytic contact effect on the oil components that adhere to the wall surface 21a and serves as an inhibitor which retards the oxidation reaction of the oil components and thus slows down the conversion of the oil components into high molecular weight products. The oxidation rate of the oil components attached to the wall surface 21a attached, which has a high temperature during operation, by which the oil components are converted into high molecular weight products is thereby reduced.

The wall surface element 21 formed of a copper plate has a thermal conductivity of about 380 to 400 W / (m · k) in the operating temperature range, wherein the compressor housing 14 For example, made of an aluminum alloy, having a thermal conductivity of less than about 240 W / (m · k), and the middle case 12 For example, made of cast iron or a cast iron alloy, has a thermal conductivity of about 50 W / (m · k) or less.

A movement of the compressor wheel 13 in an axial direction relative to the rotary shaft 11 about the seal 16 , which is located at its right end in 1 is prevented, and its movement in the other axial direction relative to the rotary shaft 11 is by a mother 17 at its left end in 1 avoided.

In the supercharger of this embodiment, the turbine is driven by the energy of the exhaust gas from the exhaust manifold, and the compressor wheel 13 turns when the combustion engine is working. The speed of the compressor wheel 13 For example, it may exceed 100,000 revolutions per minute, and the temperature at the outlet side of the diffuser section 15b can be 200 ° C or even higher.

Under these conditions, when oil components contained in the PCV gas that is returned to the intake passage become on the wall surface 21a in the diffuser section 15b attaching, the conversion of the oil into mud prevented compared to the case in which the oil components adhere to the surfaces, which are made of the same material as the body portion 22 are formed, since the wall surface element 21 has a higher activation energy for the oxidation reaction of the oil components.

When the temperature of the wall surface 21a in the diffuser section 15b increases, the rate of oxidation reaction of the oil components, which should be on the wall surface 22a attach, increase. However, according to the present invention, the rate of the oxidation reaction of the oil components attached to the wall surface 21a attach, by the catalytic contact effect of the wall surface 21a of the wall surface element 21 which serves as an inhibitor.

Therefore, since the transformation of the wall surface 21a adhering oil components in sludge is prevented, an accumulation of thermally deteriorated and carbonized sludge in the diffuser section 15b be effectively prevented.

The conversion of the oil components to sludge is prevented and the accumulation of the thermally deteriorated and carbonated sludge in the diffuser section 15b is therefore avoided because the wall surface 21a of the wall surface element 21 is a metal surface having a higher activation energy for the conversion of the oil components into the high molecular weight products. Accordingly, deterioration of the capacity of the compressor caused by the oil coking is prevented.

When a result can reduce the cost of the plant because there is no need for a structure in which the supercharging pressure controlled on the basis of the outlet temperature of the compressor becomes. Also, given the operating conditions of the turbocharger not by the supercharging pressure and the compressor outlet temperature are limited, increases the operating temperature limit of the turbocharger be what the power of the internal combustion engine improved.

In addition, since the wall surface 21a of the wall surface element 21 is made of a material having a higher thermal conductivity than the body portion 22 has, and there the wall surface element 21 is formed of a plate-like copper element, a uniform temperature distribution over the wall surface 21a in the diffuser section 15b generated, and there is no local high temperature region formed at this. As a result, the formation of sludge is sufficiently prevented and oil coking can occur even in the diffuser section 15b be prevented, in which the flow velocity of the compressor wheel 13 Air released quickly decreases and thus the oil tends to stick.

In addition, covered as the wall surface element 21 has a ring-like shape and the compressor wheel 13 surrounds the wall surface element 21 almost the entire wall surface of the middle housing 12 in the diffuser section 15b , Therefore, the conversion of the tacked oil into mud is effectively prevented, and the oil coking is reliably prevented in the entire range in which the oil tends to stick and easily converted into mud.

As in this embodiment, the wall surface element 21 is formed of copper, it is possible, the wall surface element 21 inexpensive to manufacture and thereby prevent the conversion of the oil components in sludge.

Although the wall surface element 121 Made of copper in the embodiment described above, it may be formed of any suitable material that prevents the conversion of the oil components in sludge. The material of the wall surface element 21 is chosen so that the metal surface of the wall surface 21a is oxidized by the heat, which is then generated when the energy of the air coming from the compressor wheel 13 is discharged at high speed, is converted into high pressures, and at the same time with the heat that is transferred from the exhaust gas and that is reduced by the oil components that adhere to the wall surface 21a have pinned, wherein the wall surface element 21 can fulfill the function of preventing the reaction by which mud is formed.

2 Fig. 10 is a cross-sectional view showing the general construction of a charging device according to a second embodiment of the present invention. The embodiments described below have generally the same structure as in the first embodiment, and there is a difference from the first embodiment in the structure of the wall surface member. Therefore, the components having the same structure are given the same reference numerals as the corresponding components in FIG 1 and only the differences are described in detail.

Like this in 2 is shown, the charging device of this embodiment has a wall surface element 31 , which is a film-like metal element attached to the body portion 22 is bound to the wall surface on the side of the middle housing 12 in the diffuser section 15b form, which surrounds the compressor wheel.

The wall surface element 31 forms a ring-like wall surface 31a that the compressor wheel 13 surrounds, for example, on the wall at the side of the middle housing 12 in the diffuser section 15b , The wall surface 31a has been plated by a layer of a prevention device that prevents the conversion of oil into sludge by increasing the activation energy for the oxidation reaction of the oil components attached to the wall surface of the middle casing 12 in the diffuser section 15b attached, which converts the oil components into high molecular weight products. The prevention means increases the required activation energy to above that for the oil components adhered to the wall surfaces of the channels located upstream and downstream of the diffuser section 15b located and made of the material of the body section 22 are formed.

More specifically, the wall surface element 31 be formed of a material having a higher thermal conductivity than the material of the body portion 22 has, such as cast iron. In particular, a copper film having a generally uniform thickness at the wall surface of the body portion 22 plated near the wall surface on the side of the middle case 12 in the diffuser section 15b is formed to form a smooth surface. The copper film can with the body section 22 be connected to the wall surface on the side of the middle housing 12 in the diffuser section 15b To a large extent, cover the compressor wheel 13 surrounds, ie the wall surface 31a is exposed.

Also in this embodiment, in which the wall surface element 31 is made of a copper plate, as described above, the reaction in which the oil is converted into sludge is hindered because the wall surface 31a of the wall surface element 31 is formed of a metal surface having a higher activation energy for the oxidation reaction of the oil components, which converts the oil components into high molecular weight products. Therefore, the accumulation of thermally deteriorated and carbonized sludge in the diffuser section becomes 15b prevented, and the deterioration of the performance of the compressor, which is caused by the oil-coking is prevented accordingly.

In addition, a uniform temperature distribution over the wall surface 31a in the diffuser section 15b generated, and it is likely no local high-temperature region formed at this, since the wall surface 31a of the wall surface element 31 is made of a material such as copper, which has a higher thermal conductivity than the body portion 22 has, and because the wall surface element 31 is formed of a copper plated layer (film) which covers almost the entire wall surface of the middle housing 12 covered by the diffuser section 15b is facing. Consequently, formation of a slurry can be sufficiently hindered, and oil coking even becomes in the diffuser section 15b prevents the oil from adhering to the compressor wheel due to the rapid reduction in the flow velocity of the air 13 is delivered.

Moreover, in this embodiment, an inhibitor metal sheet having a uniform thickness can be formed with ease by leaving a wide area around the compressor wheel 13 around at the end face of the middle housing 12 on the side of the diffuser section 15b is plated with copper even if the wall surface has a curved shape.

The wall surface element 31 consists of a metal-plated layer and can extend to the area behind the compressor wheel 13 extend (up to the vicinity of the outer periphery of the sealing member 16 ).

3 11 shows a cross-sectional view of the general structure of a supercharger according to a third embodiment of the present invention, showing an example in which the present invention is applied to a turbocharger incorporated in an internal combustion engine for a motor vehicle.

Like this in 3 is shown, the charging device of this embodiment has a wall surface element 41 consisting of a surface layer section 41b that has a wall surface 41a in the diffuser section 15b and a base layer section 41c made of a material having a higher thermal conductivity than the surface layer portion 41b Has. The activation energy of the oxidation reaction of the oil components through which the oil components enter high molecular weight products at the surface layer portion 41b is higher than the activation energy required on the wall surfaces made of the same material as the body portion 22 are formed. The base layer section 41c is located between the surface layer portion 41b and the body part 22 and supports the surface layer portion 41b , The wall surface element 41 has a plate-like shape as a whole.

The wall surface 41a passing through the wall surface element 41 on the wall on the side of the middle case 12 in the diffuser section 15b is formed, has an activation energy, which is required for the oxidation reaction of the oil components, on the wall of the middle housing 12 in the diffuser section 15b wherein this activation energy is greater than the activation energy required to oxidize the oil components adhered to the wall surfaces of the channels located upstream and downstream of the diffuser section 15b located and made of the material of the body section 22 are formed. This prevents the conversion of the oil into sludge.

At least the base layer section 41c of the wall surface element 41 is formed of a material having a higher thermal conductivity than the material of the body portion 22 has, such as cast iron, and the surface layer portion 41b of the wall surface element 41 can with the base layer section 41c be connected, with the wall surface 41a on the wall surface on the side of the middle housing 12 in the diffuser section 15b is exposed. The wall surface element 41 is through the body section 22 supported and can with the body section 22 be connected for example by soldering.

Also in this embodiment, the ability of the wall surface in the diffuser section 15b to prevent the mud-forming reaction, and a good thermal conductivity prevents a local temperature rise of the wall surface 41a , Therefore, converting the oil that is on the wall surface 41a adhered, effectively prevented in sludge, and oil coking is thereby prevented. Thus, the same effects are created as described in the above-described embodiments.

In the embodiments described above, the middle housing 12 so explained that it is from the wall surface element 21 and the body part 22 consists. However, the at least one housing may be the compressor housing 14 or both the middle housing 12 as well as the compressor housing 14 be. In other words, the wall surface member is not necessarily disposed in or on the wall surface on the side of the middle housing in the diffuser portion, and may be disposed on the side of the compressor housing. Alternatively, a wall panel may be disposed in or on each wall in the diffuser section. If the at least one housing the compressor housing 14 For example, the wall panel may be made of a material such as copper that has a greater ability to hinder the slurry formation reaction and that has a higher thermal conductivity than the casting surface of the material of the body portion (eg, an aluminum alloy). If the at least one housing both the middle housing 12 as well as the compressor housing 14 includes, the wall surface elements may be formed of different materials having a higher ability to hinder the mud formation reaction, and having a higher thermal conductivity than the material of the corresponding body portion, but they are preferably formed of a material such as copper, which has a greater ability to hinder the slurry forming reaction and has a higher thermal conductivity than the materials of the body portions of the two casings.

Furthermore a construction is also contemplated in which the wall panel is used is used to reduce the polarisations of the compressor discharge pressure.

For example, in the third embodiment, the base layer portion 41c of the wall surface element 41 in an elastic manner, the surface layer portion 41b thereby reducing the polarisations of the compressor discharge pressure, which typically occurs at a frequency of a few kilohertz.

Alternatively, a plurality of resonance cavities (muffling mechanism) effective to reduce the airflow noise generated by the compressor during operation may be formed behind the wall surface member (in the body portion of the at least one housing or on the back surface of the wall surface member) be as long as a uniform wall temperature distribution in the diffuser section 15b is achieved in a sufficient manner.

As described above, the present invention provides a charger at a low cost, in which the deterioration of the efficiency of the compressor caused by the oil coking can be prevented because the present invention is constructed such that the activation energy for the reaction, in which the adhering oil components are converted into high molecular weight products, becomes higher, hindering the reaction whereby oil is converted into sludge on the wall surface consisting of the wall surface member in the diffuser portion. The present invention is for each any type of supercharger applicable, in particular for turbochargers, which are used in internal combustion engines.

While the present invention by way of example with reference to their Embodiments described should be understood be that the present invention is not limited to the described embodiments or types of construction is limited. In contrast, supposedly the present invention, various modifications and equivalent Cover arrangements. Besides, though different ones are Elements of the disclosed invention in the various example combinations and types of structures are shown, also other combinations and configurations including more or less elements or just a single one Element also within the scope of the appended claims.

The charging device comprises: a rotary shaft 11 which is driven by exhaust gas; a middle housing 12 that rotates the rotary shaft 11 supported; a compressor wheel 13 that integrally with the rotary shaft 11 rotates; and a compressor housing 14 that has an inlet channel 15 which forms a diffuser section 15b around the compressor wheel 13 around, wherein a wall surface element 21 is provided, which is a wall surface of the inlet channel 15 in the diffuser section 15b formed. A body section 22 is provided so that it is the wall surface element 21 supports. The wall surface element 21 Forms the wall surface at which the activation energy of an oxidation reaction in which the oil components adhering to the wall surface are converted to high molecular weight products is higher than the activation energy required for the oxidation reaction on the wall surfaces made of the same material like the body part 22 are formed.

QUOTES INCLUDE IN THE DESCRIPTION

This list The documents listed by the applicant have been automated generated and is solely for better information recorded by the reader. The list is not part of the German Patent or utility model application. The DPMA takes over no liability for any errors or omissions.

Cited patent literature

• - JP 2005-180362 [0006]
• - JP 2005-180362 A [0006, 0011]
• - JP 2003-42145 [0007]
• JP 2003-42145 A [0007]
• - JP 61-117240 [0007]
• JP 61-117240A [0007]
• - JP 2000-291441 [0008]
• JP 2000-291441 A [0008]

Claims (15)

Charging device comprising: a rotating shaft ( 11 ), which is driven in rotation by the energy of an exhaust gas, a middle housing ( 12 ), which in a rotatable manner the rotary shaft ( 11 ), a compressor wheel ( 13 ), which by the rotary shaft ( 11 ) is supported and integrally with the rotary shaft ( 11 ) and a compressor housing ( 14 ) with the middle housing ( 12 ) is coupled to the compressor wheel ( 13 ), and that an inlet channel ( 15 ) forming a diffuser section ( 15b ) around the compressor wheel ( 13 ), characterized in that at least the middle housing ( 12 ) and / or the compressor housing ( 14 ) a wall surface element ( 21 . 31 . 41 ), which has a wall surface ( 21a . 31a . 41a ) of the inlet channel ( 15 ) in the diffuser section ( 15b ) and a body portion ( 22 ), which has the wall surface element ( 21 . 31 . 41 ) supports; and wherein the wall surface element ( 21 . 31 . 41 ) the wall surface ( 21a . 31a . 41a ), at which the activation energy for the reaction, in which the oil components adhering to the wall surface ( 21a . 31a . 41a ) in the diffuser section ( 15b ) are converted into products of high molecular weight, greater than the activation energy for the reaction of the oil components which have adhered to the wall surfaces consisting of the material of the body portion ( 22 ) are formed. Charging device according to claim 1, wherein the wall surface element ( 21 . 31 . 41 ) is formed of a material having a greater thermal conductivity than the body portion ( 22 ) Has. Charging device according to claim 1 or 2, wherein the wall surface element ( 21 . 31 . 41 ) has a metallic plate-like element which surrounds the wall surface ( 21a . 31a . 41a ) on the side of the middle housing ( 12 ) in the diffuser section ( 15b ) trains. Charging device according to claim 3, wherein the wall surface element ( 21 . 31 . 41 ) in the body portion ( 22 ) of the middle housing ( 12 ) is seated and embedded so that the wall surface ( 21a . 31a . 41a ) in the diffuser section ( 15b ) is exposed. A charging device according to claim 3 or 4, wherein the periphery and a side corresponding to the wall surface ( 21a . 31a . 41a ) of the wall surface element ( 21 . 31 . 41 ), with the body portion ( 22 ) of the middle housing ( 12 ) are connected by soldering. Charging device according to one of claims 3 to 5, wherein the wall surface element ( 21 . 31 . 41 ) has a uniform thickness and a smooth surface. A charging device according to claim 1 or 2, wherein the wall surface element comprises a metal film which is in contact with the body portion (10). 22 ) is connected to the wall surface ( 21a . 31a . 41a ) on the side of the middle housing ( 12 ) in the diffuser section ( 15b ) train. Charging device according to claim 7, wherein the wall surface element ( 21 . 31 . 41 ) with the body portion ( 22 ) of the middle housing ( 12 ) is connected so that the wall surface is connected so that the wall surface ( 21a . 31a . 41a ) in the diffuser section ( 15b ) is exposed. Charging device according to claim 7 or 8, wherein the wall surface element ( 21 . 31 . 41 ) in a space between the compressor wheel ( 13 ) and the body portion ( 22 ). Charging device according to one of claims 1 to 9, wherein the wall surface element ( 21 . 31 . 41 ) has a ring-like shape and the compressor wheel ( 13 ) surrounds. Charging device according to one of claims 1 to 10, wherein the wall surface element ( 21 . 31 . 41 ) is formed of a material through which the wall surface ( 21a . 31a . 41a ) is oxidized by the heat which is generated when the energy of the air from the compressor wheel ( 13 ) is converted into a high pressure at high speed, and simultaneously with the heat transferred from the exhaust gas and which is reduced by the oil components attached to the wall surface (FIG. 21a . 31a . 41a ). Charging device according to claim 11, wherein the wall surface element ( 21 . 31 . 41 ) consists mainly of copper. Charging device according to one of claims 1 to 12, wherein the wall surface element ( 21 . 31 . 41 ) comprises: a surface layer section ( 41b ), where its surface energy is higher than that of the wall surface ( 21a . 31a . 41a ), which consists of the material of the body portion ( 22 ) is formed, and the wall surface ( 21a . 31a . 41a ) in the diffuser section ( 15b ) trains; and a base layer section ( 41c ) formed of a material having a higher thermal conductivity than the surface layer portion (FIG. 41b ) Has. Charging device according to claim 13, wherein the surface layer section ( 41b ) by the Base layer section ( 41c ) of the wall surface element ( 41 ) is elastically supported. A charging device according to claim 13 or 14, wherein a plurality of resonance cavities which reduce the airflow noise generated by the compressor of the operation, behind the wall surface element (FIG. 21 . 31 . 41 ) are formed.