[0001] Embodiments of the subject matter herein relate to a testing kit and methods for testing a turbocharger.

BACKGROUND

[0002] Turbochargers may be used in an engine system to increase a pressure of air supplied to the engine for combustion. In one example, the turbocharger includes a turbine coupled in an exhaust passage of the engine which at least partially drives a compressor via a shaft to increase the intake air pressure. High pressure air from the turbine or the compressor may leak by non-contact labyrinth seals into an oil cavity surrounding the shaft of the turbocharger. Because the low pressure oil cavity is in fluid communication with a crankcase of the engine, crankcase pressure may increase due to the leakage of the high pressure air leading to crankcase over pressure events and removal of the turbocharger from the engine system.

[0003] In other examples, crankcase over pressure events may occur due to other factors, such as degradation of piston rings, which increases blow-by around the piston, and/or degradation of an evacuation system which maintains a pressure of the crankcase. In such examples, however, the turbocharger may still be removed from the engine system even though it is not the cause of the crankcase over pressure event, as the exact cause of the crankcase overpressure event may be unknown. BRIEF DESCRIPTION

[0004] In one embodiment, a kit for a testing apparatus for a turbocharger is provided. The turbocharger includes a turbine, a compressor, and a non-contact seal positioned between an oil cavity structure and either the turbine or the compressor, A regulatable air input is fluidically coupled to an outlet of the oil cavity and to an air supply. A flow restrictor with at least one pressure sensor is couplable to the regulatable air input. A media has instructions that specify correlating an amount of flow to a degree of leakage past the non-contact seal. From this correlation, for example, it is possible to identify whether or not crankcase overpressure is due to turbocharger shaft seal degradation, or to some other source.

[0005] In one embodiment, by coupling an air supply to the oil cavity of the turbocharger, flow of air past the non-contact seal may be measured via the flow restrictor. An increased flow may correspond to an increased degree of leakage, and may indicate degradation of the non-contact seal, for example. In this manner, degradation of the turbocharger may be indicated or detected such that the turbocharger may be removed from an engine to which it may be coupled for repair. In some embodiments, the oil cavity may be fluidically isolated from the oil system such that the turbocharger may be tested without removing the turbocharger from the engine (e.g., the turbocharger remains bolted to the engine during testing). As such, the turbocharger may be removed only if degradation is mdicated.

[0006] It should be understood that the brief description above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description, Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure,

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:

[0008] FIG. 1 shows a schematic diagram of an example embodiment of a vehicle with a turbocharger according to an embodiment of the invention.

[0009] FIG. 2 shows a cross-sectional view of a turbocharger according to an embodiment of the invention.

[0010] FIG. 3 shows a kit for a testing apparatus for a turbocharger according to an embodiment of the invention.

[0011] FIG. 4 shows a cross-sectional view of a turbocharger according to an embodiment of the invention.

[0012] FIG. 5 shows a flow chart illustrating a method for testing a turbocharger according to an embodiment of the invention.

[0013] FIG. 6 shows a flow chart illustrating a method for testing a turbocharger according to an embodiment of the invention. DETAILED DESCRIPTION

[0014] The following description relates to various embodiments of a kit for a testing apparatus for a turbocharger and methods for testing the turbocharger. In one embodiment, a kit for a testing apparatus for a turbocharger is provided. The turbocharger includes a turbine, a compressor, and a non-contact seal positioned between an oil cavity and either the turbine or the compressor. A regulatable air input is fluidically coupled to an outlet of the oil cavity and to an air supply. A flow restrictor with at least one pressure sensor is coupled to the regulatable air input, A media has instructions that specify con-elating an amount of flow to a degree of leakage past the non-contact seal. From this correlation, for example, it is possible to identify whether or not crankcase overpressure is due to turbocharger shaft seal degradation, or to some other source.

[0015] The kit may include a pressurizable bladder configured to couple to a drain passage of the oil ca vity, and a plug configured to couple to an inlet of the oil cavity, and the media may further embody human-readable instructions that specify inserting the pressurizable bladder in the drain passage of the oil cavity and inflating the pressurizable bladder, and inserting the plug into the inlet of the oil cavity. By plugging the oil inlet and the drain passage, the oil cavity may be fluidically isolated from the oil system. Because air may only exit the oil cavity through the non-contact seal, degradation of the non-contact seal may be determined by coupling an air supply to the oil cavity of the turbocharger, and measuring a flow of air past the non-contact seal. In this manner, degradation of the turbocharger may be indicated such that turbocharger may be removed from an engine to which it may be coupled only when degradation is indicated. [0016] In one embodiment, the turbocharger may be coupled to an engine in a vehicle. A locomotive system is used to exemplify one of the types of vehicles having engines to which a turbocharger, or muiti-turbocharger, may be attached. Other types of vehicles may include on-highway vehicles, off-highway vehicles, mining equipment, and marine vessels. Other embodiments of the invention may be used for turbochargers that are coupled to stationary engines, The engine may be a diesel engine, or may combust another fuel or combination of fuels. Such alternative fuels may include gasoline, kerosene, biodiesel, natural gas, and ethanol. Suitable engines may use compression ignition and/or spark ignition.

[0017] FIG. 1 shows a block diagram of an example embodiment of a vehicle system 100 (e.g., a locomotive system), herein depicted as a rail vehicle 106, configured to ran on a rail 102 via a plurality of wheels 1 12. As depicted, the rail vehicle 106 includes an engine system with an engine 104.

[0018] The engine 104 receives intake air for combustion from an intake passage 1 14. The intake passage 1 14 receives ambient air from an air filter (not shown) that filters air from outside of the rail vehicle 106. Exhaust gas resulting from combustion in the engine 104 is supplied to an exhaust passage 116. Exhaust gas flows through the exhaust passage 116, and out of an exhaust stack of the rail vehicle 106.

[0019] The engine system includes a turbocharger 120 that is arranged between the intake passage 114 and the exhaust passage 116. The turbocharger 120 increases air charge of ambient air drawn into the intake passage 114 in order to provide greater charge density during combustion to increase power output and/or engine-operating efficiency. The turbocharger 120 may include a compressor (not shown in FIG. 1) which is at least partially driven by a turbine (not shown in FIG. 1). While in this case a single turbocharger is shown, the system may include multiple turbine and/or compressor stages. The turbocharger is described in greater detail below with reference to FIGS. 2 and 4.

[0020] In some embodiments, die vehicle system 100 may further include an exhaust gas treatment system coupled in the exhaust passage upstream or downstream of the turbocharger 120. In one example embodiment, the exhaust gas treatment system may include a diesel oxidation catalyst (DOC) and a diesel particulate filter (DPF). In other embodiments, die exhaust gas treatment system may additionally or alternatively include one or more emission control devices. Such emission control devices may include a selective catalytic reduction (SCR) catalyst, three-way catalyst, NO _x trap, or various other devices or systems.

[0021] The rail vehicle 106 further includes a controller 148 to control various components related to the vehicle system 100. In one example, the controller 148 includes a computer control system. The controller 148 further includes computer readable storage media (not shown) including code for enabling on-board monitoring and control of rail vehicle operation. The controller 148, while overseeing control and management of the vehicle system 100, may be configured to receive signals from a variety of engine sensors 150, as further elaborated herein, in order to determine operating parameters and operating conditions, and correspondingly adjust various engine actuators 152 to control operation of the rail vehicle 106. For example, the controller 148 may receive signals from various engine sensors 150 including, but not limited to, engine speed, engine load, boost pressure, exhaust pressure, ambient pressure, exhaust temperature, etc, Correspondingly, the controller 148 may control the vehicle system 100 by sending commands to various components such as traction motors, alternator, cylinder valves, throttle, etc. in one example, the controller 148 may shut down the engine in response to an engine crankcase pressure greater than a threshold pressure, as will be described in greater detail below.

[0022] In one embodiment, the controller may include a communication system for reporting one or both of a flow measurement device output or a determined degradation of the turbocharger based on a measurement of pressure or flow generated by the flow measurement device, as will be described in greater detail below,

[0023] FIG. 2 shows an example embodiment of a turbocharger 200 that may be coupled to an engine, such as turbocharger 120 described above with reference to FIG. 1. In one example, turbocharger may be bolted to the engine. In another example, the turbocharger 200 may be coupled between the exhaust passage and the intake passage of the engine. In other examples, the turbocharger may be coupled to the engine by any other suitable manner.

[0024] The turbocharger 200 includes a turbine 202 and a compressor 204, Exhaust gases from the engine pass through the turbine 202, and energy from the exhaust gases is converted into rotational kinetic energy to rotate a shaft 206 which, in turn, drives the compressor 204. Ambient intake air is compressed (e.g., pressure of the air is increased) as it is drawn through the rotating compressor 204 such that a greater mass of air may be delivered to the cylinders of the engine.

[0025] In some embodiments, the turbine 202 and the compressor 204 may have separate casings which are bolted together, for example, such that a single unit (e.g., turbocharger 200) is formed. As an example, the turbocharger may have a casing made of cast iron and the compressor may have a casing made of an aluminum alloy.

[0026] The turbocharger 200 farther includes bearings 208 to support the shaft 206, such that the shaft may rotate at a high speed with reduced friction. As depicted in FIG. 2, the turbocharger may include a lubrication system to reduce degradation of the bearings and to maintain a temperature of the bearings (e.g., to keep the bearings cool), While the engine is in operation, a constant flow of engine oil or engine coolant may pass through the turbocharger, for example. In one example, pressurized engine oil may enter the turbocharger via an oil inlet 210. Excess may oil collect in an oil cavity 212, and the oil leaves the turbocharger 200 through an outlet 214.

[0027] As depicted in FIG . 2, the turbocharger 200 further includes two non-contact seals (e.g., labyrinth seals), a turbine labyrinth seal 216 positioned between the oil cavity 212 and the turbine 202 and a compressor labyrinth seal 218 positioned between the oil cavity 212 and the compressor 204.

[0028] A labyrinth seal as used herein refers to a type of mechanical seal that provides a tortuous path to help prevent leakage. In one embodiment, the labyrinth seal may be composed of many grooves or threads that press tightly against another component. Herein, the labyrinth seal is applied to a rotating shaft system, with a small clearance between tips of the labyrinth threads and the running surface. In this way, the labyrinth seal provides non-contact sealing action by controlling the passage of fluid. The labyrinth seals 216 and 218 may thus reduce leakage of the engine oil used to lubricate the bearings 208 to the turbine 202 and the compressor 204, for example, by providing a contorted, tortuous path. Because the labyrinth seals 216 and 218 are non-contact seals, friction around the bearings 208 and the shaft 206 may be reduced, while oil leakage is also reduced. In one example, the labyrinth seals 216 and 218 may be spaced a determined distance from the bearings 208. Suitable determined distances may be determined with reference to application specific parameters, such as in a range of less than -1/4000 of an inch.

[0029] High pressure air from the exhaust passage may occupy a space 220 determined by the turbine labyrinth seal 216. High pressure air from the compressor may occupy a space 222 determined by the compressor labyrinth seal 218. As such, on one side of the labyrinth seals 216 and 218, there is air at a first pressure, and on the other side of the labyrinth seals 216 and 218, there is oil at a second pressure. The oil and the air may be at a different pressure relative to each other. In some examples, a pressure imbalance may occur in the rotating assembly (e.g., bearings, shaft, etc.) resulting in wear of the bearings due to the bearings contacting (e.g., rubbing) die labyrinth seals during bearing rotation. As such, high pressure air may pass between the labyrinth seals 216 and 218 and the bearings 208 to the oil cavity structure. The presence of air in the oil cavity may lead to an increase in engine crankcase pressure, as the oil that leaves the turbocharger 200 drains to an engine crankcase (not shown).

[0030] In one embodiment, a system comprises means for supplying a determined pressure or flow of oil to an oil cavity, means for measuring a resulting pressure across, or flow through, a non-contact seal that is locatable between an oil cavity and a turbine or a compressor, and means for determining degradation of a turbocharger based on the resulting measurement of pressure or flow. As an example, means for supplying the determined pressure or flow to the oil cavity include a regulatable air input coupled to an air supply. Means for measuring the resulting pressure across or flow through the non- contact seal may include a flow measurement device, such a flow restrictor with one or more pressure sensors or gauges. Means for determining degradation of the turbocharger may include a controller and/or a look-up table.

[0031] In one embodiment, a kit is provided that interfaces with a turbine, a compressor, and a non-contact seal. The non-contact seal is positioned between an oil cavity and at least one of the turbine and the compressor. The kit includes an air source that provides a regulatable air input and can fluidically couple to an outlet of the oil cavity. The regulatable air input couples to an air supply. A flow restrictor couples to the regulatable air input. The restrictor may optionally include one or more sensors, such as a pressure gauge. The kit can include media embodying human-readable instructions that specify correlating an amount of flow to a degree of leakage past the non-contact seal.

[0032] FIG. 3 shows a kit 300 for a testing apparatus 302 that may be used to test a turbocharger, such as turbocharger 200 described above with reference to FIG. 2. As will be described in greater detail below, in some examples, the testing apparatus 302 may be used to test the turbocharger while the turbocharger is still coupled to the engine (e.g., fluid communication between the engine and the turbocharger is maintained). In other examples, the testing apparatus may be used to test the turbocharger when the turbocharger is remote from the engine (e.g., the turbocharger has been removed from the engine and fluidic communication between the engine and the turbocharger is no longer maintained). [0033] The testing apparatus 302 includes a regulatable air input 304, such as a nozzle or spout, which may be coupled to the outlet of the oil outlet of the turbocharger. The outlet and the nozzle are each configured to interact and couple with each other. In one example, the regulatable air input may be coupled directly to the oil outlet. In such an example, the turbocharger may be remote from the engine such that the oil outlet is directly accessible, In another example, the regulatable air input 304 may be coupled to the oil outlet downstream of the oil outlet. For example, the regulatable air input 304 may be coupled to a drain passage which carries oil away from the outlet of the turbocharger and to the crankcase of the engine.

[0034] FIG. 4 depicts an example in which the testing apparatus 302 may be used to test the turbocharger 200 while the turbocharger is coupled to an end of an engine block 324 of an engine. The embodiment illustrated in FIG. 4 includes at least some of the same components as the embodiment illustrated in FIG. 2. Components that function similarly are identified by like reference numerals.

[0035] As depicted in FIG. 4, oil drains from the oil cavity 212 into an oil drain passage 326 which is fluidically coupled to the crankcase of the engine such that the oil may be cooled and recirculated, A pressurized bladder 328, such as a pig or other suitable flow inhibitor, may be inserted into the drain passage 326 and inflated such that fluid flow to the engine crankcase is cut-off. in one example, the pressurized bladder may be inflated with the same air supply that is delivered to the oil cavity. In another example, the pressurized bladder may be self-inflatable. In other embodiments, an expansion plug may be used to block fluid flow to the crankcase. Further, a plug 330 operable to block a flow of fluid may be inserted into the oil inlet 210 of the oil cavity 212 to stop the flow of oil to the turbocharger 200. In this manner, the oil cavity 212 of the turbocharger 200 may be fluidically isolated from the engine crankcase. As such, an airflow may be supplied to the oil outlet 214 via a regulatable air input to pressurize the oil cavity 212 while the turbocharger remains coupled to the engine.

[0036] Continuing with FIG. 3, the regulatable air input 304 may be coupled to an air supply 306 via a tube 308, such as a rubber hose, metal pipe, or the like. A distal end of the tube 308 may include a connector 310 for connecting to the air supply 306. The air supply may be a tank of compressed of compressed air or compressor, such as an auxiliary compressor that supplies compresses air to various components of the engine, such as an electrically driven compressor that is driven by generator a generator coupled to the engine, for example.

[0037] The testing apparatus further includes a valve 3 12 coupled between the air supply 306 and the regulatable air input 304. The bail valve 312 may be a quarter turn valve such as a ball valve, butterfly valve, or the like, which may be opened and closed by a user of the testing apparatus 302. As depicted in FIG. 3, a regulator 314 is positioned between the valve 312 and the regulatable air input 304 in order to regulate the flow of air entering the oil cavity. Further, a flow measurement device including a flow restricior 316 with two pressures gauges 318 and 320 is coupled between the valve 312 and the regulatable air input 304 to measure the rate of fluid flow through the regulatable air input 304. In other embodiments, the flow restrictor may be coupled to one or more sensors. Suitable sensors may include one or more pressure gauges alone or in combination with a temperature gauge, a compositional sensor, a magnetic monitor, and the like, In one embodiment, the flow measurement device flow restrictor with one or more pressure gauges may be an orifice plate,

[0038] The kit 300 includes an instructional booklet 322. Alternative media may include written, human-readable mstructions that correlate an amount of flow relative to a degree of leakage past a non-contact seal. The instructional booklet 322 may specify coupling the regulatable air input 304 to the outlet of the oil cavity of the turbocharger. In one example, the instructions may specify coupling the regulatable air input 304 directly to the oil outlet when the turbocharger is removed from the engine. In another example in which the turbocharger remains coupled to the engine, the instructions may specify coupling the regulatable air input 304 upstream of the outlet of the oil cavity. Further, in such an example, the instructions may specify inserting a pressurized bladder into the drain passage of the oil cavity and inflating the pressurized bladder, and plugging the oil inlet with a plug to restrict oil flow to the oil cavity.

[0039] In this and other embodiments, the instructional booklet 322 may include instructions that specify supplying air from the air supply 306 to the oil cavity via the regulatable air input 304, in one example, the instructions may further specify opening the valve 312 coupled to the regulatable air input 304 downstream of the flow restrictor 316 to supply air to the oil cavity. The instructions may further specify measuring the amount of flow with the flow restrictor 316 with the two pressure gauges 318 and 320. In this manner, the amount of flow may be correlated to a degree of leakage past the non- contact labyrinth seal such that degrada tion of the turbocharger may be indicated.

[0040] The instructional booklet 322 may be a media that has human-readable instructions. In other embodiments, the human-readable instructions may be provided on a computer text file, an audio or video file, or any other suitable media. For example, the human-readable instructions of the instructional booklet 322 may be stored as PDF files on a computer. A computer is a contemplated form of media that may be used to embody machine-readable instructions. In other embodiments, the machine -readable instructions may be provided via flash memory or a network server.

[0041] In an embodiment, a method for a testing apparatus for a turbocharger, the turbocharger including a turbine and a compressor, and a non-contact seal between an oil cavity and one of the turbine and the compressor, comprises inserting a plug into an inlet of the oil ca vity, and supplying an airflow to an outlet of the oil ca vity with a regulatable air input of the testing apparatus, the regulatable air input coupled to an air supply, The method further comprises, measuring a flow through the non-contact seal with a flow restrictor with at least one pressure gauge, the flow ^r restrictor coupled to the regulatable air input, and indicating degradation of the turbocharger when the flow across the non- contact seal is greater than a threshold,

[0042] Continuing to FIG. 5, a method 500 for testing a turbocharger with a testing apparatus, such as the testing apparatus 302 described above, is shown. The method includes supplying a regulated airflow to an oil cavity of a turbocharger to determine a degree of leakage past a non-contact seal, such as the compressor labyrinth seal or the turbine labyrinth seal.

[0043] At 502, a plug is inserted into the oil cavity inlet. In this way, a flow of oil to the oil cavity is reversibly reduced or cut-off. Further, fluid flow out of the oil cavity, such as airflow may be restricted. At 504, airflow is supplied to the oil cavity outlet, In one example, the airflow may be supplied directly to the oil cavity outlet via the regulatable air input. In other examples, the airflow may be supplied to a location downstream of the oil outlet via a regulatable air input. For example, the airflow may be supplied to the location downstream of the oil outlet when the turbocharger is coupled to an engine. The airflow may be regulated via a regulator, for example, in this way, a predetermined pressure or flow may be supplied to the oil cavity such that the oil cavity is pressurized at a predetermined pressure.

[0044] At 506 of method 500, a flow through a flow restrictor is measured. For example, because the labyrinth seals are non-contact seals, some of the air supplied to the oil cavity will flow out of the oil cavity past the labyrinth seals. When the bearings and/or one or both of the labyrinth seals are worn due to contact between the bearings and labyrinth seals, a greater amount of flow will flow out of the oil cavity resulting in a greater amount of flow, or pressure change, measured by the flow restrictor. At 508, it the flow that is measured is evaluated to determine if it is greater than a threshold value.

[0045] If it is determined that the flow is less than the threshold value, at 512 it is indicated that the labyrinth seals of the turbocharger are not degraded. But if it is determined that the flow is greater than the threshold value, at 510 it is determined that the degradation of the turbocharger is evident. The degradation may be due to degradation of one or both of the non-contact seals.

[0046] FIG. 6 shows a flow chart illustrating a method 600 for testing a turbocharger with a testing apparatus. The method 600 may be carried out when the turbocharger is coupled to an engine in a vehicle. At 602, the engine operating conditions are determined. The operating conditions may include boost pressure, engine crankcase pressure, engine oil temperature, ambient pressure, ambient temperature, and the like. [0047] At 604, the crankcase pressure is sensed and is compared to a threshold pressure, During engine operation, the engine crankcase pressure may he negative with respect to the ambient (e.g., atmospheric) pressure. The threshold may be a positive pressure or an increase in pressure indicating the pressure is increasing, for example. In some examples, the threshold pressure may be a crankcase over pressure. The crankcase pressure may be measured by a pressure sensor in communication with the engine controller, for example, such that an operator of the vehicle in which the engine is positioned is notified (e.g., by a malfunction indicator lamp (MIL), or the like) that the crankcase pressure is increasing. If it is determined that the crankcase pressure is less than the threshold pressure, method 600 moves to 612 and current engine operation is continued.

[0048] If it is determined that the engine crankcase pressure exceeds the threshold pressure, at 606 the engine is turned off or de-rated. The engine may be shut down or stopped such that the engine is no longer spinning, Once the engine is shut down, at 608 a pressurized bladder is inserted into the oil drain passage and inflated to create a sealing engagement with the passage inner surface. The pressurized bladder may cut off fluid communication between the engine crankcase and the oil cavity. At 610, the method 500 described above with reference to FIG. 5 is carried out. A degradation of the turbocharger may be diagnosed while the turbocharger remains coupled to the engine in the vehicle,

[0049] Thus, degradation of a turbocharger leading to increased engine crankcase pressure may be diagnosed while the turbocharger remains coupled to the engine or if the turbocharger is disassembled from the engine. By reversibiy plugging the oil inlet and the drain passage, the oil cavity may be fluidically isolated from crankcase and the oil system during testing of the turbocharger such that air may only leak out of the oil cavity through orifices around the labyrinth seals, which are inherent in non-contact seals. In this manner, degradation of the non-contact seals may be determined, as flow through the orifices increases as the size of the size of the orifices increases due to degradation. Further, crankcase over pressure events in which the turbocharger is removed from the engine system even though the turbocharger is not degraded may be reduced.

[0050] As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of the present invention are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising," "including," or "having" an element or a plurality of elements having a particular property may include additional such elements not having that property. The terms "including" and "in which" are used as the plain-language equivalents of the respective terms "comprising" and "wherein." Moreover, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements or a particular positional order on their objects.

[0051] This written description uses examples to disclose the invention, including the best mode, and also to enable a person of ordinary skill in the relevant art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those of ordinary skill in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent stmctural elements with insubstantial differences from the literal languages of the claims.