Predicted torsional damper break determination in a machine system

Abstract

Predicting shock absorber damage in a machine system includes monitoring machine operating parameters and temperature parameters related to torsional load on a crankshaft. The predictive alert strategy also includes populating an operating history of the machine system based on the monitored parameters, calculating a shock absorber damage term based on the operating history, and triggering a shock absorber damage alert if the shock absorber damage term exceeds a threshold.

Description

TECHNICAL FIELD

[0001] The present disclosure relates generally to monitoring torsional vibration damper health, and more particularly to predictively alerting to an anticipated damper failure based on damper and machine system operating history. BACKGROUND

[0002] Mitigating vibration and other load phenomena in various machines is a persistent challenge. Machine systems can be subjected to various externally and internally generated vibrations, shocks, and other harsh usage conditions. For rotating machines, torsional load and vibration damping is often required. For example, in the case of an engine crankshaft, the crankshaft does not rotate at a constant speed, but rather undergoes rapid accelerations and decelerations in response to combustion in the engine cylinders, compression of gases used for combustion, exhaust, opening of valves, application of external loads, and other phenomena. In this dynamic environment, torsional loads can be additive, subtractive, or create resonances that can damage the engine crankshaft or degrade the performance of the engine or related systems over time.

[0003] In modern machine systems requiring torsional load damping, torsional dampers are often employed. In the case of certain engine systems, the torsional damper can comprise a viscous torsional damper having a rotatable mass in contact with a relatively high viscosity fluid, providing inertia that can reduce or eliminate the occurrence or intensity of problematic torsional loads. Any type of torsional damper can experience performance degradation or failure over time. One strategy for diagnosing torsional damper status is presented in U.S. Patent No. 8,935,041, in which a driveline having a driveshaft is equipped with a torsional vibration damper. The diagnostic strategy proposes capturing a baseline vibration signal of the driveshaft in a baseline condition, capturing a working vibration signal of the driveshaft in a working condition deviating from the baseline condition, and comparing the baseline vibration signal to the working vibration signal. While the strategy presented in the '041 patent can have certain applications, the technology appears to require dedicated additional hardware and is relatively complex. SUMMARY

[0004] In one aspect, a method for predictively alerting to damper failure in a machine system includes monitoring a machine operating parameter associated with at least one of an amplitude, a frequency, or a direction of a torsional load on a crankshaft in the machine system, the machine system having a viscous torsional damper coupled thereto. The method further includes monitoring a temperature parameter. The method also includes populating an operating history of the machine system based on the monitored machine operating parameter and the monitored temperature parameter, calculating a damper failure term based on the populated operating history, and triggering a damper failure alert based on the calculated damper failure term.

[0005] In another aspect, a machine system includes a machine having a crankshaft supported for rotation in a housing, and a viscous torsional damper coupled with the crankshaft. The machine system further includes a damper failure warning system having a warning device, and an electronic control unit in communication with the warning device. The electronic control unit is structured to monitor a machine operating parameter associated with at least one of a magnitude, frequency, or direction of a torsional load on the crankshaft, and to monitor a temperature parameter. The electronic control unit is further structured to command activation of the warning device based on a computed damper failure term.

[0006] In yet another aspect, an engine control system includes an electronic control unit structured to receive engine operating data of an engine operating parameter associated with at least one of a magnitude, frequency, or direction of a torsional load on a crankshaft in an internal combustion engine, and to receive temperature data for a temperature parameter. The electronic control unit is further structured to populate an engine operating history based on the data of the engine operating parameter and the data of the temperature parameter, and to compute a damper failure term based on the populated engine operating history. The electronic control unit is further structured to compare the computed damper failure term to a stored threshold term, and to command activation of a damper failure warning device based on the comparison of the computed damper failure term to the stored threshold term. BRIEF DESCRIPTION OF DRAWINGS

[0007] Figure 1 is a schematic diagram of a machine system according to one embodiment;

[0008] Figure 2 is a functional block diagram of an electronic control unit according to one embodiment;

[0009] Figure 3 is a table representing the functionality of a software algorithm according to one embodiment; and

[0010] Figure 4 is a flow chart illustrating exemplary control logic flow according to one embodiment. DETAILED DESCRIPTION

[0011] Referring to Figure 1shown in the context of an internal combustion engine. The machine 12 (hereinafter referred to as "engine 12") can comprise a compression ignition internal combustion engine, such as a diesel engine having a housing 13 with a plurality of cylinders 16 formed therein. In a conventional four-stroke engine cycle, the cylinders 16 can each be equipped with a piston 18 movable between a top dead center position and a bottom dead center position. The engine 12 further includes a crankshaft 20 supported for rotation in the housing 13. The engine 12 can be operable to power a generator 14 to provide electrical power for supply to an electrical grid, or for operation of a drive motor in a vehicle, or for other purposes such as operation of a pump, compressor, or industrial equipment.

[0012] In other cases, the engine 12 can be coupled with a driven machine other than a generator. The engine 12 further includes a drive pulley 22 rotated by rotation of the crankshaft 20 to operate a driven pulley 26 through a belt 24. Rotation of the driven pulley 26 can rotate an output shaft 28 that operates equipment associated with the engine 12, such as a transmission pump, hydraulic pump, compressor, camshaft, or other type of equipment. The engine 12 can be equipped with a gear train or another rotational system instead of a pulley system. The engine 12 further includes a viscous torsional damper 30 coupled with the crankshaft 20. The damper 30 can include a housing 32, an inertia ring 35 configured to rotate within the housing 32, and a fluid space 31 containing viscous fluid for communicating rotation between the housing 32 and the inertia ring 34 in a generally known manner. The damper 30 can further include other components such as various types of bearings.

[0013] As noted above, in certain internal combustion engines, particularly four-stroke piston diesel engines, crankshaft rotation can be uneven and dynamic due to the different piston strokes of many pistons, including intake, compression, power, and exhaust. In addition to the varying forces communicated between the pistons and the crankshaft, the firing order of the individual cylinders can dictate that the crankshaft continuously accelerate and decelerate. It is generally desirable to prevent these rotational irregularities and vibrations from being transmitted to the belt drive system, gear train, or other driven equipment.

[0014] In the machine system 10, the damper 30 is used to mitigate various torsional vibrations and loads that the crankshaft 20 can experience. As a result, the damper 30 can be exposed to relatively high levels of mechanical stress and strain, including shear forces on the viscous damping fluid. When dampers in machine systems such as engine systems become worn, a decrease in comfort in vehicle applications or other phenomena can be observed due at least in part to degradation of the damping fluid, an increase in engine noise. Following usage and replacement intervals, as well as regular inspection, can help ensure the desired torsional damper functionality.

[0015] However, the useful life of a damper can be unpredictable based on variable factors. The challenge can be more pronounced where the engine is used to operate a generator, for example, in standby genset applications, as standby gensets can be operated under a variety of loads depending on load requirements and used in different locations exposed to relatively extreme temperatures and temperature variations. The present disclosure provides a strategy for predicting damper failure in a machine system 10.

[0016] To this end, the machine system 10 further includes a damper failure alert system or control system 36. The control system 36 can be an onboard engine control system having an electronic control unit 38 configured to receive engine operating data of engine operating parameters associated with at least one of the magnitude, frequency, or direction of torsional load on the crankshaft 20 in the engine 12. The electronic control unit 38 can also be configured to receive temperature data of temperature parameters.

[0017] The control system 36 can monitor machine operating parameters, monitor temperature parameters, and populate an operating history of the machine system 10 based on the monitored machine operating parameters and the monitored temperature parameters. The electronic control unit 38 can further calculate a damper failure term based on the populated operating history and compare the calculated damper failure term to a stored threshold term. The damper failure term can be a quantitative or qualitative numerical value associated with a relative degree of wear or performance degradation of the viscous damper.

[0018] The threshold can be a numerical value that has been determined to be associated with a relative degree of wear or performance degradation that warrants alerting an operator that further operation of the machine system 10 should be suspended or modified until, for example, the damper 30 can be replaced. The threshold term can be a value that, if equal to or exceeded by the damper failure term, for example, warrants engine shutdown, reduced power rating, or operating the machine in limp-home mode only. The threshold term can be determined empirically or potentially through simulation for an individual engine or a class of similar engines. Comparing the damper failure term to the threshold term can include a greater than or equal to comparison, a less than or equal to comparison, or via other similar comparisons. Based on the comparison of the calculated damper failure term to the stored threshold term, the electronic control unit 38 can command activation of a damper failure alert device 39 in the control system 36.

[0019] As noted above, the monitored machine operating parameter is associated with at least one of the magnitude, frequency, or direction of the torsional load on the crankshaft 20. The term associated with means directly or indirectly indicative of, approximating, or associated with. In one embodiment, the machine operating parameter can include a load factor of the engine 12, which can be generally understood as a proportion of the engine load to the rated engine load. It has been observed that at certain engine load factor levels, the vibration or torsional load magnitude can be greater than at other engine load factor levels. It can also be the case that certain frequencies, including resonant frequencies, can be more observable at certain load factor levels than at other load factor levels. The association of engine load factor with the direction, magnitude, or frequency of the torsional load on the crankshaft can be determined empirically, or potentially through simulation, for a class of similar engines or a single engine. Other parameters that have a known, determinable, or estimable relationship with engine load can be targeted for monitoring engine operating parameters in a similar manner. Thus, by monitoring the load factor, the electronic control unit 38 can gather information about the current operating state of the engine 12 that can be understood as more or less likely to be associated with undesirable or problematic torsional loads, which in turn are associated with relatively greater wear on the damper 30. In one embodiment, the monitored temperature parameter includes a monitored ambient temperature. In other embodiments, another temperature parameter can be used.

[0020] The control system 36 can also be equipped with engine sensors 41 for generating engine operating data of engine operating parameters. The engine sensors 41 can include one or more sensors that can individually or collectively monitor one or more parameters indicative of engine load. Since engine load cannot be directly sensed, the engine sensors 41 can include one or more of a mass flow sensor in the engine intake system (not shown), a fuel supply sensor, an engine speed sensor, a torque sensor, a temperature sensor, etc. Virtual engine load sensors can be used as known in the art.

[0021] The control system 36 can also be equipped with a temperature sensor 37, which can be an ambient temperature sensor exposed to the ambient environment outside of the engine 12. The control system 36 also includes an alert device 39 in communication with the electronic control unit 38. The alert device 39 can include an operator alert light such as a check engine light, or another operator perceptible alert device such as a speaker or buzzer. The alert device 39 can be positioned in an operator cab in a mobile vehicle application. The alert device 39 can also include an illuminable indicator or icon on a control panel or even a graphical user interface. In yet another embodiment, the shock absorber damage alert can be logged in a memory and retrieved or viewed by a technician using a service tool. As discussed above, the electronic control unit 38 can trigger and output a shock absorber damage alert signal based on the calculated shock absorber damage term. Triggering the shock absorber damage alert can include commanding activation of the alert device 39, as discussed further herein.

[0022] Referring now also to Figure 2 a functional block diagram of the electronic control unit 38 illustrating additional details is shown. The electronic control unit 38 can include an input / output interface 48 and at least one processor 50. The processor 50 can be any suitable processor such as a microprocessor, microcontroller, or field programmable gate array (FPGA). The electronic control unit 38 also includes a memory 52. The memory 52 can be any suitable computer readable memory such as RAM, ROM, SDRAM, EEPROM, flash memory, hard drives, or other memory. The memory 52 stores computer executable program instructions that, when executed by the processor 50, can perform the predictive alert strategy discussed herein.

[0023] In one implementation, the electronic control unit 38 comprises an engine control unit configured to perform not only the predictive alert logic of the present application, but also standard engine control functions. To this end, the memory 52 can store engine control software 54 and various engine maps 56. Figure 2 Also depicted in FIG. 4 is an engine / operator input 40, which can be received by the electronic control unit 38 and includes any of a variety of parameters such as rotational speed, pressure, temperature, and other parameters monitored during operation of the engine 12. Operator inputs such as a speed request, a fueling request, or other similar parameters can also be included in the input 40. The processor 50 can receive the input 40 and generate engine control instructions 46 by executing the engine control software 54. The memory 52 can also store a shock absorber damage alert software 58, as well as a damage score map 60, discussed further herein.

[0024] Figure 2Engine load input 42 and temperature input 44 are also shown. Engine load input 42 may directly or indirectly indicate or include data associated with engine load, as discussed herein, and may include signals from engine sensor 41. Engine load input 42 may potentially be used together with other information to determine the current engine load rate. Temperature input 44 may include signals from temperature sensor 37. Based on engine load input 42 and temperature input 44, processor 50 may generate a warning command 53 to activate warning device 39 by executing damper damage warning software 58.

[0025] Reference Figure 3 A table 70 illustrating the software control functions according to the invention is shown. Multiple cells 72 in the first table can be filled by the electronic control unit 38 to reflect the operating history of the mechanical system 10. Cell 72 represents a container filled with the number of timed operations of the mechanical system 10. It can be noted that the batteries 72 are temperature-isolated; the left column of batteries represents a combination of load rate and temperature less than "X" °C, and the right column of batteries represents a combination of load rate and temperature above X °C. In one embodiment of the disclosed concept, X °C can be equal to an ambient temperature of approximately 40 °C.

[0026] As discussed further below, the number of engine 12 operations for each combination of load rate and temperature can be recorded, for example, at a task rate of 1 second. Table 70 also shows multiple cells 74 representing calculations for damage per unit, again separated by temperature and load rate corresponding to cell 72. Figure 3 In the diagram, since no information is stored in unit 72, the total engine hours shown are zero. Similarly, the total damage shown at 76 is also zero. The event indication shown at 78 did not display a warning at that time. As will become clearer from the following description, when machine system 10 is operating, the number of engine operations per unit (e.g., in seconds) can be recorded, damage per unit can be calculated, the total damage or total damage can be calculated, and potential other processing steps can be performed to determine whether an event has occurred that meets the conditions for a warning indication, or whether an event has occurred that meets the conditions for no warning indication.

[0027] It will also be recalled that the electronic control unit 38 calculates a shock absorber damage term based on the populated operational history. This shock absorber damage term can include a total shock absorber damage term. In other words, based on the manner in which the machine system 10 is operated and based on the conditions under which the machine is operated, a total damage term can be calculated that reflects a relative wear that the shock absorber 30 can experience, or a level of performance degradation that can occur. It is also contemplated that certain combinations of load factors, temperatures, and / or other potential factors are expected to have a relatively greater impact on shock absorber life. To this end, the electronic control unit 38 can calculate a total shock absorber damage term based on a weighted accumulation of the number of operations of the machine system 10 for each of a plurality of bins. Operations at a given time in some bins can be expected to have more or less of an impact on shock absorber life than operations at a given time in other bins, with each bin number of operations being weighted accordingly. For example, where operations in one bin are associated with relatively greater damage than another bin, the first bin can be weighted more heavily. It will also be recalled that the memory 52 can store a damage score map 60.

[0028] The damage score map 60 can include stored damage score terms for each of a plurality of bins that are empirically determined. The processor 50 can read the stored damage score terms for use in calculating an amount of damage per bin, such as by multiplying the number of operations per bin by the damage score term or "shock absorber life weighting term" in the following equation. One example calculation can include multiplying 3.5 hours above 40°C at 95-100 load rate % by a shock absorber life weighting term of 1.5 to yield a damage amount of 5.25 for a given bin. Another example can include multiplying a number of operations of 4.0 hours below 40°C at 0-59 load rate % by a shock absorber life weighting term of 0.5 to yield a damage amount of 2.0 for a given bin. These numbers are for illustrative examples only. The calculation of total damage can include calculating a total shock absorber damage term based on a weighted accumulation of the number of operations per bin for a plurality of bins. One example calculation of this total shock absorber damage term includes calculating the total shock absorber damage term by the following equation:

[0029] TD = TA*AF + TB*BF... TX*XF

[0030] where: TD is the total damage;

[0031] TA, TB... TX are the per bin timing operation number; and

[0032] AF, BF... XF are the per bin shock absorber life weighting term.

[0033] Reference is now made to Figure 4FIG. 10 shows a flowchart 100 illustrating an exemplary logic flow according to one embodiment of the disclosed concept. The flowchart 100 begins at block 105 with an inquiry as to whether the engine 12 is operating. If the engine 12 is not operating, the logic can proceed to block 106 to exit. Alternatively, if the engine 12 is operating, the logic proceeds to block 110 to determine whether a shock absorber damage alert strategy is enabled. If the alert strategy is not enabled, the logic proceeds to block 111 to exit. However, if the alert strategy is enabled, the logic proceeds to block 115 to increment a timer. In one implementation, the electronic control unit 38 can perform several functions related to shock absorber damage assessment within a one second time interval, although the present invention is not limited thereto.

[0034] The logic proceeds from block 115 to block 120 to time engine operating seconds per tank. Again, different time intervals can be used to time engine operation. It should be remembered that, consistent with the illustration in FIG. 9, or using other combinations of load rate, temperature or other factors, the engine operating seconds per tank can include engine operating seconds for each of a plurality of combinations of engine load rate and ambient temperature. Temperature data as discussed herein is input to the logic flow at block 125, and engine operating data as discussed herein is input to the logic flow at block 130. Figure 3

[0035] The logic proceeds from block 120 to block 135 to calculate damage per tank, as discussed herein. The logic proceeds from block 135 to block 140 to calculate cumulative damage for all tanks, such as by the equation set forth herein. The logic proceeds from block 140 to block 145 to inquire as to whether the total damage (TD) is greater than a threshold. Block 145 can include comparing the shock absorber damage term to a stored threshold term, again as discussed herein. If the TD is greater than the threshold, the logic proceeds to block 150 to command activation of an alert device, such as lighting a light, sounding an alarm, or sending a text message to an operator's mobile device, etc. The logic proceeds from block 150 to block 151 to exit. If the TD is less than or equal to the threshold, the logic can return to block 115 to again increment the timer. The strategy can also include storing the engine operating seconds per tank at block 155 for long term storage on at least one of the memory 52, a local drive, a remote drive, etc. Storing the engine operating seconds per tank at block 155 can enable transfer of previously recorded operating history data to a replacement electronic control unit. New or replacement electronic control units are typically cloned for installation in an engine. In this way, accumulated shock absorber damage can be taken into account even when an electronic control unit in a mechanical system is replaced, but a torsion shock absorber that has not reached the end of its useful life is not replaced.

[0036] ​This specification is for the purpose of a summary of the application only and is not to be construed as limiting the scope of the application in any way. Thus, other embodiments of the application will become apparent to those skilled in the art upon study of the drawings and the following claims. Other aspects, features, and advantages will become apparent to those of ordinary skill in the art, upon reading the following description of the current embodiments along with the accompanying drawings, and by practicing the same. As used herein, the articles "a" and "an" are intended to include one or more items, and can be used interchangeably with the phrase "one or more." Where only one item is intended, the term "one" or similar language is used. Also, as used herein, the terms "has," "have," "having," or the like are intended to be open-ended terms. Further, the phrase "based on" is intended to mean "based, at least in part, on" unless explicitly stated otherwise.

Claims

1. A method for predicting damper failure in a warning machine system, comprising: monitoring a machine operating parameter associated with at least one of a magnitude, frequency, or direction of torsional load on a crankshaft in the machine system, the machine system having a viscous torsional damper coupled thereto; monitoring a temperature parameter; populating an operating history of the machine system based on the monitored machine operating parameter and the monitored temperature parameter; calculating a damper failure term based on the populated operating history; and triggering a damper failure warning based on the calculated damper failure term, wherein, monitoring the machine operating parameter includes monitoring a load factor of an internal combustion engine in the machine system; monitoring the temperature parameter includes monitoring an ambient temperature; and populating the operating history further includes populating a plurality of bins with timed operating counts of the machine system at different combinations of load factor and temperature.

2. The method of claim 1, wherein the calculating the damper failure term includes calculating a damper total failure term based on a weighted accumulation of the operating counts of each of the plurality of bins.

3. The method of claim 2, wherein the calculating the damper total failure term includes calculating the damper total failure term by the equation: TD = TA*AF + TB*BF... TX*XF TD is total damage; wherein: TA, TB... TX are timed operating counts per bin; and AF, BF... XF are damper life weighting terms per bin.

4. A machine system, comprising: a machine including a crankshaft supported for rotation in a housing, and a viscous torsional damper coupled to the crankshaft; a damper failure warning system including a warning device, and an electronic control unit in communication with the warning device, the electronic control unit configured to: monitor a machine operating parameter associated with at least one of a magnitude, frequency, or direction of torsional load on the crankshaft; monitor a temperature parameter; populate an operating history of the machine system based on the monitored machine operating parameter and the monitored temperature parameter; calculate a damper failure term based on the populated operating history; and command activation of the warning device based on the calculated damper failure term, wherein, monitoring the machine operating parameter includes monitoring a load factor of an internal combustion engine in the machine system; monitoring the temperature parameter includes monitoring an ambient temperature; and populating the operating history further includes populating a plurality of bins with timed operating counts of the machine system at different combinations of load factor and temperature.

5. The machine system of claim 4, wherein the warning device includes an operator warning light.

6. The machine system of claim 4 or 5, wherein: the damper failure warning system further includes an ambient temperature sensor configured to generate an ambient temperature signal, and the electronic control unit is configured to monitor the temperature parameter by receiving the ambient temperature signal; and the machine includes a compression ignition internal combustion engine having a plurality of pistons coupled to the crankshaft, and the machine operating parameter includes a load factor of the internal combustion engine. ​ ​ 7. The machine system of claim 4 or 5, wherein: the electronic control unit is further structured to time the number of operations of the machine system at different combinations of load rate and temperature; the electronic control unit is further structured to populate a plurality of bins in an operating history of the machine system with the timed number of operations; and the damper damage term comprises a total damper damage term, and the electronic control unit is further structured to calculate the total damper damage term based on a weighted accumulation of the number of operations of each of the plurality of bins.

8. An engine control system, comprising: an electronic control unit structured to receive engine operation data for an engine operation parameter associated with at least one of a magnitude, a frequency, or a direction of torsional load on a crankshaft in an internal combustion engine, and structured to receive temperature data for a temperature parameter; the electronic control unit further structured to populate an engine operating history based on the data for the engine operation parameter and the data for the temperature parameter, and to calculate a damper damage term based on the populated engine operating history; and the electronic control unit further structured for comparing the calculated damper damage term to a stored threshold term, and commanding activation of a damper damage alert device based on the comparison of the calculated damper damage term to the stored threshold term, wherein, the engine operation parameter comprises a load rate; the temperature parameter comprises an ambient temperature; and populating an engine operating history further comprises populating a plurality of bins with timed number of operations of the internal combustion engine at different combinations of load rate and temperature.

9. The engine control system of claim 8, wherein: the damper damage term comprises a total damper damage term; the electronic control unit is further structured to time the number of operations of the internal combustion engine at a plurality of combinations of load rate and temperature; the electronic control unit is further structured to populate a plurality of bins in the operating history with the timed number of operations; and the electronic control unit is further structured to calculate the damper damage term based on a weighted accumulation of the number of operations of each of the plurality of bins.

Images