Ported shroud with filtered external ventilation

1. An apparatus, for use with a turbocharger having a compressor wheel including blades that define an inducer and an exducer, an intake-air air filter, and a body forming an intake air passage extending from the intake-air filter to the inducer and placing the intake-air air filter in direct fluid communication with the inducer, comprising:

a compressor housing configured to receive the wheel, wherein the compressor housing defines an impeller passage within which air is to be compressed by the blades, and a bypass port opening into the impeller passage between the inducer and exducer, wherein the bypass port forms a passage leading between the impeller passage and the atmosphere without extending through the intake air passage; and

a filter adapted to filter air passing between the bypass port and the atmosphere.

2. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

the apparatus of claim 1 ; and

a turbine configured to drive the compressor wheel within the compressor housing.

3. The apparatus of claim 1 , and further comprising a filter housing, wherein:

the filter housing defines an intake-air internal compartment that opens up to an intake-air filter portion of the filter, the intake-air internal compartment forming an intake-air chamber in direct fluid communication with the impeller passage;

the filter housing defines a bypass-air internal compartment that opens up to a bypass-air filter portion of the filter exclusive from the intake-air portion of the filter, the bypass-air internal compartment forming a bypass-air chamber in direct fluid communication with the bypass port; and

the intake-air and bypass-air chambers are not substantially in direct fluid communication.

4. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

the apparatus of claim 3 ; and

a turbine configured to drive the compressor wheel within the compressor housing.

5. The apparatus of claim 3 , wherein the filter housing is further configured to form intake-air and bypass-air ventilation compartments on opposite sides of the filter from the intake-air and bypass-air internal compartments, respectively, and wherein the ventilation compartments are configured with separate vents configured to prevent a substantial flow between the chambers of the intake-air and bypass-air ventilation compartments.

6. The apparatus of claim 5 , wherein the vents separated by a distance adequate to prevent a substantial flow between the chambers of the intake-air and bypass-air ventilation compartments.

7. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

the apparatus of claim 6 ; and

a turbine configured to drive the compressor wheel within the compressor housing.

8. A compressor system for use in a turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer; and

the apparatus of claim 1 .

9. A method for improving the efficiency of a turbocharger including a compressor wheel having blades that define an inducer and an exducer, and further including a compressor housing configured to receive the wheel, comprising:

venting air out of a compressor housing impeller passage, within which the wheel spins to compress air, via a bypass port opening into the impeller passage between the inducer and exducer, to the atmosphere such that the vented air does not interact with intake air being routed through an intake port to the inducer.

10. The method of claim 9 , wherein the step of venting includes a step of filtering air passing between the impeller passage and the atmosphere via the bypass port.

11. The method of claim 10 , wherein:

intake air being routed through the intake port to the inducer is passed through a first portion of a filter; and

the step of filtering includes passing the passed air through a second portion of the filter.

12. The method of claim 11 , and further comprising separating atmospheric airflows on an atmospheric side of the filter such as to prevent a substantial flow rate between air exiting via the second portion of the filter and air entering via the first portion of the filter.

13. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

a compressor housing configured to receive the wheel; and

a means for venting air out of a compressor housing impeller passage, within which the wheel spins to compress air, via a bypass port opening into the impeller passage between the inducer and exducer, to the atmosphere such that the vented air does not interact with intake air being routed through an intake port to the inducer;

wherein the means for venting includes a means for filtering air passing between the impeller passage and the atmosphere via the bypass port;

wherein the means for filtering is configured such that intake air being routed through the intake port to the inducer is passed through a first portion of a filter; and

wherein the means for filtering is further configured such that bypass air being vented from the impeller passage via the bypass port passes through a second portion of the filter.

14. The turbocharger of claim 13 , and further comprising a means for separating atmospheric airflows on an atmospheric side of the filter such as to prevent a substantial flow rate between air exiting via the second portion of the filter and air entering via the first portion of the filter.

15. An apparatus, for use with a turbocharger having a compressor wheel including blades that define an inducer and an exducer, comprising:

a compressor housing configured to receive the wheel, wherein the compressor housing defines an impeller passage within which air is to be compressed by the blades, an intake port configured to provide intake air to the inducer, and a bypass port opening into the impeller passage between the inducer and exducer, the bypass port placing the impeller passage in fluid communication with the atmosphere without extending through an intake air passage;

a filter adapted to filter air passing between the bypass port and the atmosphere; and

a filter housing;

wherein the filter housing defines an intake-air internal compartment that opens up to an intake-air filter portion of the filter, the intake-air internal compartment forming an intake-air chamber in direct fluid communication with the impeller passage;

wherein the filter housing defines a bypass-air internal compartment that opens up to a bypass-air filter portion of the filter exclusive from the intake-air portion of the filter, the bypass-air internal compartment forming a bypass-air chamber in direct fluid communication with the bypass port; and

wherein the intake-air and bypass-air chambers are not substantially in direct fluid communication.

16. An apparatus, for use with a turbocharger having a compressor wheel including blades that define an inducer and an exducer, an intake-air air filter, and a body forming an intake air passage placing the intake-air air filter in direct fluid communication with the inducer, comprising:

a compressor housing configured to receive the wheel, wherein the compressor housing defines an impeller passage within which air is to be compressed by the blades, and a bypass port opening into the impeller passage between the inducer and exducer;

a filter; and

a filter housing;

wherein the bypass port forms a passage leading between the impeller passage and the atmosphere without extending through the intake air passage;

wherein the filter is adapted to filter air passing between the bypass port and the atmosphere;

wherein the filter housing defines an intake-air internal compartment that opens up to an intake-air filter portion of the filter, the intake-air internal compartment forming an intake-air chamber in direct fluid communication with the impeller passage;

wherein the filter housing defines a bypass-air internal compartment that opens up to an intake-air filter portion of the filter exclusive from the intake-air portion of the filter, the bypass-air internal compartment forming a bypass-air chamber in direct fluid communication with the bypass port; and

wherein the intake-air and bypass-air chambers are not substantially in direct fluid communication.

17. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

the apparatus of claim 16 ; and

a turbine configured to drive the compressor wheel within the compressor housing.

18. The apparatus of claim 16 , wherein the filter housing is further configured to form intake-air and bypass-air ventilation compartments on opposite sides of the filter from the intake-air and bypass-air internal compartments, respectively, and wherein the ventilation compartments are configured with separate vents configured to prevent a substantial flow between the chambers of the intake-air and bypass-air ventilation compartments.

19. The apparatus of claim 18 , wherein the vents separated by a distance adequate to prevent a substantial flow between the chambers of the intake-air and bypass-air ventilation compartments.

20. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

the apparatus of claim 19 ; and

a turbine configured to drive the compressor wheel within the compressor housing.

21. A method for improving the efficiency of a turbocharger including a compressor wheel having blades that define an inducer and an exducer, and further including a compressor housing configured to receive the wheel, comprising:

venting air within a compressor housing impeller passage, within which the wheel spins to compress air, via a bypass port opening into the impeller passage between the inducer and exducer, to the atmosphere such that the vented air does not interact with intake air being routed through an intake port to the inducer;

wherein the step of venting includes a step of filtering air passing between the impeller passage and the atmosphere via the bypass port.

22. The method of claim 21 , wherein:

intake air being routed through the intake port to the inducer is passed through a first portion of a filter; and

the step of filtering includes passing the passed air through a second portion of the filter.

23. The method of claim 22 , and further comprising separating atmospheric airflows on an atmospheric side of the filter such as to prevent a substantial flow rate between air exiting via the second portion of the filter and air entering via the first portion of the filter.

24. A turbocharger, comprising:

a compressor wheel having blades that define an inducer and an exducer;

a compressor housing configured to receive the wheel; and

a means for venting air in a compressor housing impeller passage, within which the wheel spins to compress air, via a bypass port opening into the impeller passage between the inducer and exducer, to the atmosphere such that the vented air does not interact with intake air being routed through an intake port to the inducer;

wherein the means for venting includes a means for filtering air passing between the impeller passage and the atmosphere via the bypass port;

wherein the means for filtering is configured such that intake air being routed through the intake port to the inducer is passed through a first portion of a filter; and

wherein the means for filtering is further configured such that bypass air being vented from the impeller passage via the bypass port passes through a second portion of the filter.

25. The turbocharger of claim 24 , and further comprising a means for separating atmospheric airflows on an atmospheric side of the filter such as to prevent a substantial flow rate between air exiting via the second portion of the filter and air entering via the first portion of the filter.