JP3385041B2 - compressor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and more particularly to a compressor which can be used, for example, in a turbocharger for supplying compressed air to an internal combustion engine.

[0002]

BACKGROUND OF THE INVENTION Air compressors typically consist of tubular inlets and outlets and vaned impeller wheels rotatably mounted in a housing that rotate to move gas in the inlets to the outlets. ing. The housing has an inner wall defining a surface that is placed in close proximity to the radially outer end of the vane supported by the wheel.

Already, “map width enhanced” (MW
E) A turbocharger using a compressor housing has been implemented. Such a structure is disclosed in US Pat. No. 4,930,979. In this configuration, the inlet is composed of a first portion and a second portion arranged end to end. The first portion of the inlet has an inner wall surface that is an extension of a surface of the housing inner wall portion that faces the vane of the impeller wheel. A flow path is defined radially outward of the first portion of the inlet, one end of the flow path opening adjacent the wheel in a plane defined by the inner wall of the housing. The other end of the flow path opens into a second portion of the inlet adjacent the first portion of the inlet.

At high flow rates through the impeller wheel, air passes through the flow path from the inlet to the compressor wheel. When the flow through the impeller wheel is slow, the direction of air flow through the flow path is reversed and air passes from the wheel to the junction between the first and second portions of the inlet. As is well known, such a flow path configuration stabilizes the compressor performance.

It is already known that compressors using MWE compressor housings generate a higher level of noise than compressors with conventional housings.

German Patent DE-A-4027175.9 discloses a compressor having an MWE structure including a flow path of the type described above. In this configuration, a ring member is inserted in the second portion of the inlet, and the ring member is the second portion of the inlet.
The opening cross-sectional area of the part is reduced and the first inlet
The portion extends radially inward with respect to the flow path defined radially outward of the portion. According to the above-mentioned publication, such a configuration utilizes the inlet flow to stabilize the compressor performance. However, the inner diameter of the ring structure adjacent the first portion of the inlet is set to be larger than the inner diameter of the first portion of the inlet, and thus the pressure wave pressure pres- sure.
The wavefronts will be propagated axially into the gas flow in the second portion of the inlet. For this reason, the arrangement disclosed in the German patent specification is not considered to have a significant impact on the noise problems associated with MWE compressor constructions.

One object of the present invention is to eliminate or alleviate the noise problems mentioned above.

According to the present invention, there is provided a housing defining an inlet and an outlet, and an impeller wheel rotatably mounted in the housing and rotating to move gas in the inlet to the outlet.
The housing has an inner wall defining a surface located in close proximity to a radially outer end of a vane supported on a wheel, and an inlet is disposed end to end. The first of the inlets, which consists of parts
The portion has an inner surface that is an extension of the surface of the housing inner wall, and a flow path is defined radially outward of an outer surface of the first portion of the inlet, one end of the flow path defining the inner wall of the housing. In a compressor that opens in a plane adjacent to the wheel and the other end of the flow path opens in a second section adjacent to the first section of the inlet, in a compressor of the outer surface of the first section of the inlet adjacent to the second section. The second of the inlets having a diameter adjacent to the first part
A compressor is provided which is characterized in that it is at least substantially identical to the diameter of the inner surface defined by the portions.

The diameter of the inner surface of the first portion of the inlet adjacent to the second portion of the inlet is at least substantially relative to the diameter of the inner surface defined by the second portion of the inlet adjacent to the first portion. Can be the same.

Preferably, the second portion of the inlet defines an annular baffle mounted on the housing. The baffle can be mounted by various conventional methods, for example by screwing or bolting it into the housing (fitting recess in the housing) or by elastic engagement. Can be done by.

An annular lip is defined on the baffle, and the annular lip extends toward the first portion of the inlet to form an annular chamber radially outward of the inner surface of the second portion of the inlet; The annular chamber can be configured to communicate with the flow path. The annular lip terminates a few mm from the tubular housing section that defines the first section of the inlet.

The diameter of the radially inner surface of the baffle can be reduced towards the first portion of the inlet. The baffle can be formed, for example, in the shape of a truncated cone with a half angle of the cone of 30 to 60 °. Alternatively, the baffle can be constructed from an axially arcuate member, for example, an elliptical portion or a compound curved surface portion. The baffle can be manufactured from a sheet member having a uniform wall thickness. In an alternative configuration, the baffle can define a radially inner surface that forms a tubular surface.

The baffle can carry a tilting adapter for connecting the second part of the inlet to an associated unit, the size of the adapter being adapted to the size of said associated unit. The adapter may also support at least one dividing wall located radially outside the first portion of the inlet and extending into the flow path.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

Referring to the accompanying drawings, FIG. 1 shows a conventional inlet section for a compressor that does not have a Map-Woods enhanced structure. In this conventional configuration, the housing 1 defines an inlet 2 that communicates with an impeller wheel 3 that supports a vane 4. The inner wall of the housing 1 defines a surface 5 which is arranged in close proximity to the radially outer end of the vane 4. When the impeller wheel 3 rotates about the axis of rotation indicated by the dashed line 6, gas flows from the inlet 2 to the outlet (not shown).

While the conventional configuration shown in FIG. 1 is not stable under certain operating conditions and operates satisfactorily only in a relatively limited region, especially with respect to impeller wheel speed, this problem is illustrated in FIG. Format map uids
It is known to be overcome by providing an enhanced compressor.

Referring to FIG. 2, the inlet portion shown has a housing 7 in which an impeller wheel 8 is located.
Is rotatably attached. The vanes 9 on the impeller wheel are located in close proximity to the surface 10 defined by the housing. When the wheel spins, the air
An inlet, indicated generally by the reference numeral 11, is drawn into the spiral-shaped outlet 12.

The inlet 11 can be regarded as consisting of two parts, namely two parts arranged end to end and passing through the tip 13 of the inner wall 14 and divided by an assumed plane perpendicular to the axis of rotation. In other words, the inlet generally designated by the reference numeral 11 is the dashed line 15 in FIG.
Can be considered to consist of a first part for the right side of and a second part for the left side of the dashed line 15 in FIG.

The inner wall 14 defines a chamber 17 between itself and the outer wall 16. The outer wall 16 to the left of line 15 defines a second portion of the inlet. Slot 18 is inside wall 1
Surface 1 that extends 4 and is adjacent to impeller wheel vane 9
It penetrates to 0. The inner wall 14 is web-supported against the wall 16, one end 19 of which is shown in the lower part of FIG.

When the impeller wheel 8 rotates at high speed, air is sucked from the inlet not only through the opening defined radially inside the inner wall 14 but also through the chamber 17 and the slot 18. However, as the speed of rotation of the impeller wheel decreases, the pressure drop in the slots 18 decreases and even reverses, and at this time a portion of the air passing through the openings defined radially inward of the inner wall 14 is removed. , Through the slot 18 and the chamber 17 back into the inlet. It is already known that this stabilizes the operation of the input stage of the compressor.

In this way, the first part of the inlet,
That is, the radially inward opening of the inner wall portion 14 allows less air to flow than the second portion of the inlet to the left of line 15 when the wheel is operating at high speeds, while the compressor is operating at low speeds. In the second of the inlet
It will be appreciated that more air will flow than a portion. The difference between the two flows depends on the air flow through the flow path defined by slot 18 and chamber 17. The flow path has one end opening adjacent to the wheel and the other end opening into a second portion of the inlet.

Referring now to FIG. 3, a MWE compressor inlet construction similar to that in FIG. 2 is shown, however, this works with the baffle according to the present invention. Here, the same components as those in FIG. 2 and the subsequent drawings are designated by the same reference numerals. Figure 3
As shown in, the baffle comprises a frustoconical end portion 20, the diameter of which tapers toward the tip 13 of the inner wall 14. This defines a chamber between the radially outer side of the baffle and the radially inner side of the wall 16, which communicates with the chamber 17. The end portion 20 closest to the inner wall portion 14
Has an inner diameter that is substantially the same as the inner diameter of the inner wall portion 14. It will be seen that the tip 13 of the inner wall 14 juts out slightly in the shape of a funnel close to the baffle. It will also be appreciated that the baffle is locked in place by engaging its protrusion 21 into the slot 22 in the wall 16.

According to the configuration shown in FIG. 3, the wave leading portion of the pressure propagating through the slot 18 and the chamber 17 flows into the first portion of the inlet, that is, the radially inner opening of the inner wall portion 14. Suddenly intrudes into the extremely high speed air stream. Noise is also reduced by redirecting the path of the airflow through the chamber 17 and the slots 18. Furthermore,
The tangential velocity at the wave front of pressure propagating through the chamber is minimized. This is the case when the inner diameter of the baffle end proximate the tip 13 of the inner wall 14 is less than or substantially the same as the outer diameter of the tip 13 of the wall 14.

Next, FIG. 4 shows a modification of the embodiment according to FIG. That is, the adapter 23 is connected to the baffle. The adapter 23 has a relatively small diameter inlet end 24. The diameter of this inlet end 24 can be selected to match the diameter of the associated device (not shown) to which the compressor inlet is to be connected. Therefore, according to the configuration of FIG. 4, not only the noise generated by the MWE inlet configuration can be reduced, but also the inlet structure of a fixed size can be easily applied to the related parts of the apparatus of different sizes.

Next, FIG. 5 shows the propagating noise outside the compressor structure for a range of compressor speeds and air flows resulting from a standard MWE configuration. This is compared with the noise output shown in FIG.
Here, the noise output of FIG. 6 is achieved after modification by simply mounting the conical ring equipment of the type shown in FIG. 3 on the standard MWE structure of the type producing the noise output shown in FIG. is there. FIG. 7 shows the noise reduction achieved by mounting the ring of FIG. It is understood that this reduces noise output over the entire range of compressor speed and air flow.

Referring to FIG. 8, the top curve shows the noise monitored 1 m away from a standard MWE compressor of the type shown in FIG. The middle curve shows the noise output achieved after mounting a conical ring of the type shown in FIG. The bottom curve is a standard non-M of the form shown in Figure 1.
7 shows the noise output from the WE structure. As described above, the cone-shaped equipment of the type shown in FIG. 3 exerts a great effect even if the increase in output noise due to the MWE structure is not completely eliminated.

Next, FIG. 9 illustrates the noise reduction achieved by mounting a conical ring of the type shown in FIG. 3 on another standard MWE construction. The five curves shown are
10 shows the achieved results for the five air flows indicated by the lower symbols in FIG. 9.

The series of curves shown in FIG. 10 show the effect of using different materials on the baffle according to the invention. All displayed noise outputs were monitored under compressor speed of 90,000 rpm. Curve 25 shows the output from a standard MWE compressor. Another curve is
The output measured by introducing a predetermined baffle according to the present invention is shown. Curve 26 corresponds to plastic baffle, curve 27 corresponds to aluminum baffle, curve 28
Corresponds to a steel baffle. Similar curves for various materials,
By deriving from tests on baffle geometry and baffle mounting plans, it is possible to design baffles that will work best for a particular application.

11 to 17 show an alternative baffle structure different from the baffle structure shown in FIG. Figure 1
1 and 12, a groove 29 is formed on the inner surface of the outer wall 16, and this groove is indicated by the plastic baffle 32 (shown in broken lines in FIG. 11 and in solid lines in FIG. 12). The protrusion 30 formed on the elastic arm 31 extending from The radially inner surface 33 of the baffle forms a part of the cone surface and also the inner wall 1
It will be appreciated that the chamfer 34 on 4 is also arranged to form part of the same cone surface. Therefore, in the embodiment of FIG. 11, the minimum inner diameter of the baffle is slightly larger than the maximum inner diameter of the surface 34 of the inner wall 14. Thus, a gap is defined between the baffle and the end of the inner wall 14, however, this gap is typically 3 mm wide and the walls 15 and 1
It is arranged so that the noise propagated from the space between 6 enters the air flow passing through the gap in a direction substantially perpendicular to the air flow direction. The air flow through the gap defined between the end of the baffle and the adjacent end wall of the housing is smooth.

Next, FIG. 13 shows the noise output monitored in the compressor operating at 90,000 rpm. Curve 35 shows the output with a standard MWE structure. Curve 36 shows the output monitored by mounting a baffle of the type shown in FIG. 12 in place, and in this case the angle of the baffle surface 33 is 2 relative to the axis of rotation of the compressor.
It is inclined at 1 °. Curve 37 shows the effect of a baffle with an inclination angle of 30 °, and curve 38 shows a baffle angle of 45 °.
Shows the output when set to °. Thus, it will be appreciated that different effects can be achieved by varying the baffle angle, again introducing a test to determine the ideal structure to suit a particular application. It's relatively easy.

Next, FIG. 14 shows a structure having the same performance as the structure of FIG. The baffle 39 has a cylindrical rim 40, which is the outer wall 1 of the compressor housing.
It can be fixed to 6 via, for example, a bolt extending in the radial direction. Normally four bolts are used. In this case, the baffle portion 40 shown in FIG. 14 is rotated 90 ° outward so that the baffle is fixed to the outer wall portion through a bolt extending in the wall portion in the axial direction. It will of course be understood that it can be configured.

FIG. 15 shows another structure in which the baffle is composed of a lip portion 41 extending in the radial direction and a main body portion 42 having an arcuate shape in an axial cross section. The axial cross section can be defined, for example, in a portion of an elliptical surface, but it is of course possible to use another compound or simpler curved structure.

In all of the above-mentioned embodiments, the baffle is made of thin-walled member. Such a configuration has the advantages that the baffle is formed to be relatively lightweight, is easy to manufacture, and is easy to install. However, it is also possible to configure the embodiment of the present invention to a fixed structure rather than a thin structure. One example of such a configuration is shown in FIG. In the configuration of FIG. 16, the baffle 43 has a relatively heavy vehicle, from which the lip 44 extends toward the inner wall 14. Such a structure can be manufactured, for example, by casting.

FIG. 17 shows the same baffle as that shown in FIG. 16, but in this case an arcuate front edge 45 and an arcuate internal recess 46 are provided.

[0035]

The baffles described above reduce self-generated noise due to pressure gradients between the compressor blades and the slots provided to achieve the MWE characteristics. The effect of this baffle is to introduce the tangential velocity of the wave front of the pressure propagating through the MWE flow path such that it diverts the pressure wave and is substantially perpendicular to this main flow. Due to
It is considered to be exhibited by reducing it to the minimum. The pressure wave thus rapidly penetrates into the relatively high velocity air stream traveling to the compressor inlet.

It will be appreciated that performance can be optimized by adjusting the size of the baffles to effectively "tune" the configuration to help suppress particular frequencies. In this way, it is possible to design a baffle which is particularly adaptable to any compressor construction and which in particular can provide maximum noise reduction at a particular compressor speed.

While various methods have been described for securing the baffle in place, any type of conventional method may be used, such as rotationally inserting the baffle, mechanically securing it with a through rod, bolt or adhesive, or by a snug fit. Needless to say, the fixing by the method can be applied.

The baffle can be made from any suitable material, such as various conventional metals or synthetic resins.

[Brief description of drawings]

FIG. 1 is a schematic side view of a typical inlet portion of a turbocharger compressor.

FIG. 2 is a partial cross-sectional view showing the inlet portion of a known turbocharger having a map Widos enhanced compressor housing.

FIG. 3 is a schematic cross-sectional view of an MWE compressor housing similar to that shown in FIG. 2 cooperating with a baffle according to the present invention.

4 is a cross-sectional view showing the structure shown in FIG. 3 with an adapter added.

FIG. 5 is an explanatory diagram showing characteristics of blade path noise expected from the compressor inlet structure as shown in FIG. 3 having no baffle according to the present invention.

FIG. 6 is an explanatory diagram showing empirical characteristics of blade path noise when the baffle of FIG. 3 is included.

FIG. 7 is an explanatory diagram showing characteristics of reducing blade noise corresponding to the difference between the plots of FIGS. 5 and 6;

FIG. 8 is an explanatory diagram showing characteristics of noise with respect to air flow ratio ranges at a constant speed for various compressor inlet structures.

9 is an explanatory diagram showing a characteristic of an effect on noise in an air flow ratio range when the baffle shown in FIG. 3 is introduced.

FIG. 10 is an explanatory diagram showing a characteristic of an effect on blade path noise by adjusting a material used for manufacturing the baffle shown in FIG.

FIG. 11 is a cross-sectional view showing the assembly of the inlet portion of the compressor and the baffle of the present invention inserted in the inlet portion.

12 is a cross-sectional view showing the baffle shown in FIG.

FIG. 13 is an explanatory diagram showing characteristics of an effect obtained by changing the cone angle of the baffle of the type shown in FIG.

FIG. 14 is a sectional view showing an alternative embodiment of the present invention.

FIG. 15 is a sectional view showing an embodiment as another alternative of the present invention.

FIG. 16 is a sectional view showing an embodiment as still another alternative of the present invention.

FIG. 17 is a cross-sectional view showing another alternative embodiment of the present invention.

[Explanation of symbols]

1 Housing 2 Inlet 3 Impeller Wheel 4 Vane 5 Surface 6 Dashed Line 7 Housing 8 Impeller Wheel 9 Vane 10 Surface 11 Inlet 12 Swirl (Outlet) 13 Tip 14 Inner Wall 15 Dashed Line 16 Outer Wall 17 Chamber 18 Slot 19 Web 20 Baffle 21 Projection 22 slot 23 adapter 24 inlet end 25-28 curve 29 groove 30 protrusion 31 elastic arm 32 plastic baffle 33 radial inner surface 34 chamfer 35-38 curve 39 baffle 40 cylindrical rim 41 lip 42 body 43 baffle 44 lip portion 45 arcuate front end edge portion 46 arcuate internal recess

Continuation of the front page (56) References JP-A-59-25100 (JP, A) JP-A-57-110800 (JP, A) JP-A 4-17198 (JP, U) US Patent 4708584 (US, A) International Publication 92/3660 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F04D 1 /-29 /

Claims (8)

(57) [Claims] 1. A housing comprising a housing defining an inlet and an outlet, and an impeller wheel rotatably mounted in the housing for rotating to move gas in the inlet to the outlet, the housing being supported by the wheel. An inner wall defining a surface located in close proximity to the radially outer end of the vane,
The inlet then comprises first and second portions arranged end to end, said first portion of the inlet having an inner surface which is an extension of said surface of the housing inner wall, and the first portion of the inlet. A flow path is defined radially outward of an outer surface of the flow path, one end of the flow path opening adjacent the wheel at the surface of the inner wall of the housing and the other end of the flow path adjacent the first portion of the inlet. In the compressor opening into the second portion, the diameter of the outer surface of the first portion of the inlet adjacent the second portion is less than the diameter of the inner surface defined by the second portion of the inlet adjacent the first portion. Is substantially the same as
Yes, inside the first part of the inlet adjacent to the second part
The second part of the inlet whose face diameter is adjacent to the first part
At least substantially with respect to the diameter of the inner surface defined by
Are identical and the second part of the inlet is the housing
Defined by an annular baffle mounted on,
The baffle defines an annular lip, which annular lip
Extending towards the first part of the inlet
An annular chamber is formed on the outer side in the radial direction on the inner surface of the two parts
A compressor characterized in that the annular chamber of the lever is connected to the flow path . 2. A radially inner surface of the baffle, a compressor of claim 1 wherein the reduced towards its diameter to the first portion of the inlet. 3. The compressor of claim 2 wherein the baffle comprises a frustoconical member that slopes inwardly toward the first portion of the inlet. 4. The compressor according to claim 2 , wherein the baffle is a member having an arcuate shape in the axial direction. 5. A baffle compressor according to any one of claims 1 to 4 having a substantially uniform wall thickness. 6. The compressor of claim 1, wherein the radially inner surface of the baffle defining a cylindrical surface. 7. slope adapter, according to claim 1 to 6 are connected to the end away from the wheel with respect to the baffle
Compressor according to any one of. 8. A baffle having at least one exterior extending into a flow path radially outward of the first portion of the inlet.
The compressor according to any one of claims 1 to 7 , which supports a wall portion .