Patent Publication Number: US-10309276-B2

Title: On-engine fluid monitoring system

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to lubrication systems for engines and, more particularly, relates to fluid monitoring systems for such lubrication systems. 
     BACKGROUND 
     Generally, a fluid, such as oil, is circulated through an engine for lubrication during operation. Before flowing to the engine, the oil usually passes through a filter to remove contaminants. In addition to lubricating the engine, the oil also cools the engine by absorbing heat. The hot oil typically flows from the engine into an oil pan or sump to be recirculated through the system. The hot oil, however, generally needs to be cooled before recirculation through the system. As such, in some large engine systems, for example, an oil pump typically pumps the hot oil from the oil pan to flow through an oil cooler to cool the oil before flowing to the oil filter. 
     In some large engine systems, an oil cooler bypass valve is arranged upstream of the oil cooler to regulate the flow of oil to the oil cooler. For example, with the engine running, the oil may be hot and less viscous such that the oil cooler bypass valve regulates the hot oil to flow directly to the oil cooler for cooling. On the other hand, during engine start-up when the oil is typically cold and more viscous, the oil cooler bypass valve directs a portion of the cold oil to bypass the oil cooler to avoid damaging the oil cooler. As the oil circulates through the system, it may be desirable to monitor the properties of the oil to ensure proper oil performance and efficient engine operation. In such large engine systems, the oil flow and pressure is relatively high compared to smaller engine systems and, as such, may present difficulties in effectively monitoring the properties of the oil as it circulates through the large engine system. 
     U.S. Patent Application Publication No. 2016/0061071 is a general reference of an engine system including an oil cooler and a bypass apparatus arranged so that oil may selectively bypass the oil cooler. However, improvements in oil and other fluid monitoring systems for engines continue to be sought. 
     SUMMARY 
     In accordance with an aspect of the disclosure, a monitoring system for monitoring fluid parameters in a lubrication system of an engine is provided. The monitoring system may include an input conduit configured to be in fluid communication with the lubrication system at a first location upstream of an oil cooler of the lubrication system. A monitoring device may be in fluid communication with the input conduit. An output conduit may be in fluid communication with the lubrication system at a second location downstream of the oil cooler. The output conduit may include a flow restrictor configured to provide a desired pressure and flow of a fluid to the monitoring device via the input conduit. 
     In accordance with another aspect of the disclosure, an engine is provided. The engine may include a cooler bypass in fluid communication with, and downstream of, a pump. The cooler bypass may include a bypass valve. An oil cooler may be in fluid communication with, and downstream of, the cooler bypass. A monitoring system may fluidly couple a first location upstream of the cooler bypass to a second location downstream of the oil cooler. The monitoring system may include a flow resistor configured to provide a desired pressure and flow of a fluid to flow through the monitoring system from the first location to the second location. 
     In accordance with yet another aspect of the disclosure, a lubrication system for an engine is provided. The lubrication system may include an oil cooler. The oil cooler may include a cooler inlet and a cooler outlet. The cooler inlet may be upstream of the cooler outlet. A first location may be upstream of the cooler inlet and a second location may be downstream of the cooler outlet. A monitoring device may include an input conduit and an output conduit. The input conduit may be in fluid communication with the first location. The output conduit may be in fluid communication with the second location. One of the input conduit and the output conduit may include a flow restrictor configured to provide a desired pressure and flow of a fluid to the monitoring device via the input conduit. 
     These and other aspects and features of the present disclosure will be more readily understood upon reading the following detailed description when taken in conjunction with the accompanying drawings. Aspects of different embodiments herein described can be combined with or substituted by one another. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an off-highway truck, in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a block diagram illustrating an exemplary lubrication system of an engine, in accordance with an embodiment of the present disclosure; 
         FIG. 3  is a partial cross-sectional view of a cooler bypass in a cooler-flow position, in accordance with an embodiment of the present disclosure; 
         FIG. 4  is a partial cross-section view of a cooler bypass in a bypass flow position, in accordance with an embodiment of the present disclosure; and 
         FIG. 5  is a block diagram illustrating a sample sequence of steps which may be practiced in accordance with the teachings of the present disclosure. 
     
    
    
     It is to be noted that the appended drawings illustrate only typical embodiments and are therefore not to be considered limiting with respect to the scope of the disclosure or claims. Rather, the concepts of the present disclosure may apply within other equally effective embodiments. Moreover, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of certain embodiments. 
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , an exemplary off-highway truck constructed in accordance with the present disclosure is generally referred to by reference numeral  8 . The off-highway truck  8  may be utilized in a wide variety of industries such as, but not limited to, mining, earth-moving, agricultural, and construction, to name a few example. The off-highway truck  8  includes an engine  10  (shown in  FIG. 2 ). The engine  10  may be any type of engine such as, but not limited to, diesel engines, gas turbine engines, marine engines, generator sets, and other engines well-known in the industry. It should be generally understood that while the engine  10  is illustrated in use with the off-highway truck  8 , the engine  10  may also be utilized in other environments such as, but not limited to, marine propulsion, power generation, and fluid extraction. 
     With reference to  FIG. 2 , the engine  10  includes a lubrication system  12  in fluid communication therewith for circulating a fluid, such as oil for example, through the engine  10  for lubrication and cooling. The lubrication system  12  includes a pump  14  in fluid communication with an oil pan  16  or sump, which is in fluid communication with the engine  10 . The pump  14  is further in fluid communication with an inlet port  18  of a cooler bypass  20 . The inlet port  18  of the cooler bypass  20  receives oil from the pump  14  via supply flow path  22 . The cooler bypass  20  also includes a bypass valve  24 , a bypass port  26 , and an outlet port  28  in fluid communication with a cooler inlet  30  of an oil cooler  32 . 
     The bypass valve  24  of the cooler bypass  20  is configured to control oil flow to pass through the outlet port  28  to the oil cooler  32  via a cooler flow path  34  and, under certain conditions such as when the oil is cold and viscous, to direct part of the oil flow to bypass the oil cooler  32  via the bypass port  26 . The oil cooler  32  also includes a cooler outlet  36  in fluid communication with a filter inlet  38  of an oil filter  40  such that the cooler flow path  34  continues from the cooler bypass  20  through the oil cooler  32  and to the oil filter  40 . As such, the filter inlet  38  of the oil filter  40  receives oil from the cooler outlet  36  of the oil cooler  32  via the cooler flow path  34 . Moreover, the filter inlet  38  of the oil filter  40  is in fluid communication with the bypass port  26  of the cooler bypass  20  via a bypass flow path  42 , such that the filter inlet  38  can also receive oil from the bypass port  26  of the cooler bypass  20 , depending on the position of the bypass valve  24 . In some embodiments, the bypass flow path  42  is in fluid communication with the cooler flow path  34  downstream of the cooler outlet  36  so that the oil flowing from the bypass port  26  combines with oil flowing from the cooler outlet  36  to flow to the filter inlet  38 . The oil filter  40  is also in fluid communication with the engine  10  and filters out contaminants from the oil before flowing to the engine  10 . 
     With reference to  FIG. 3 , an exemplary cooler bypass, such as the cooler bypass  20 , is illustrated to depict the operational relationship of the bypass valve  24  within the cooler bypass  20  for controlling oil flow. The bypass valve  24  includes a spool  44  and a biasing member  46 , which urges the spool  44  away from a base  48  such that the spool  44  is arranged in a cooler-flow position (illustrated in  FIG. 3 ) to restrict oil flowing from the inlet port  18  to the bypass port  26  while allowing oil to flow from the inlet port  18  to the oil cooler  32 . Further, the biasing member  46  continues to urge the spool  44  in the cooler-flow position until pressure exerted on the spool  44  overcomes a preload force of the biasing member  46 , at which point, the force of pressure on the spool  44  compresses the biasing member  46  toward the base  48  until the spool  44  reaches a bypass-flow position. With the spool  44  arranged in the bypass-flow position, as illustrated in  FIG. 4 , access is open to the bypass port  26  such that oil flowing from the inlet port  18  is partially diverted through the bypass port  26  to the oil filter  40  via the bypass flow path  42 . 
     For example, when the oil is cold and viscous, such as during engine start-up, the oil pressure on the spool  44  is greater than the preload force of the biasing member  46  forcing the spool  44  to transition from the cooler-flow position to the bypass-flow position such that a portion of oil begins diverting through the bypass port  26  to bypass the oil cooler  32 . On the other hand, when the oil is warm or hot, such as during operation of the engine  10 , the oil pressure on the spool  44  is less than the preload force of the biasing member  46  such that the biasing member  46  biases the spool  44  into the cooler-flow position restricting oil flow to the bypass port  26 . 
     Referring back to  FIG. 2 , the lubrication system  12  further includes a monitoring system  50  for monitoring properties of the oil. The monitoring system  50  includes an input conduit  52 , an output conduit  54 , and a monitoring device  56  in fluid communication with the input conduit  52  and the output conduit  54 . The monitoring device  56  is in fluid communication with the supply flow path  22  via the input conduit  52  and is in fluid communication with the oil filter  40  via the output conduit  54 . The monitoring system  50  further includes a flow restrictor  58 . The flow restrictor  58  is configured to limit the pressure and flow of oil through the monitoring system  50  to be in compliance with the operational pressure and flow parameters of the monitoring device  56 . In some embodiments, the flow restrictor  58  is disposed in the output conduit  54  and may be a defined orifice constricting passage through the output conduit  54  resulting in limiting the pressure and flow of oil passing through the input conduit  52  of the monitoring system  50  from the supply flow path  22  such that the pressure and flow of oil through the input conduit  52  is less than that of the supply flow path  22 . For example, the flow of oil through the input conduit  52  is an order of magnitude less than the flow of oil at the supply flow path  22  such that the temperature of the oil flowing to the oil filter  40  is not significantly impacted. 
     For example, a peak pressure at a first location  60  upstream of the cooler bypass  20  is greater than an exit pressure at a second location  62  downstream of the cooler outlet  36  of the oil cooler  32 . Based on the peak pressure at the first location  60  being greater than the exit pressure at the second location  62 , the flow restrictor  58  is, thus, appropriately dimensioned and configured to provide the desired pressure and flow of oil through the monitoring system  50 , which is less than the peak pressure at the first location  60  and is in compliance with the operational pressure and flow parameters of the monitoring device  56 . As such, the monitoring device  56  receives the oil at the desired pressure and flow for monitoring the oil, which then flows to oil filter  40  via the output conduit  54 . In some other embodiments, the flow restrictor  58  (illustrated as dotted lines in  FIG. 2 ) is disposed in the input conduit  52  instead of the output conduit  54  to effect the same desired pressure and flow through the monitoring device  56  of the monitoring system  50 . 
     Still referring to  FIG. 2 , the monitoring device  56  is configured to monitor oil quality parameters and/or monitor debris in the oil. In some embodiments, the monitoring device  56  includes an oil quality sensor  64  for monitoring oil quality parameters such as, but not limited to, oil temperature, viscosity, density, and dielectric constant. Additionally or alternatively, the monitoring device  56  includes an oil debris sensor  66  for measuring metallic (e.g. ferrous and/or non-ferrous) and/or non-metallic debris in the oil. 
     INDUSTRIAL APPLICABILITY 
     In general, the present disclosure may find applicability with engines utilized in high power applications for any number of industrial settings such as, but not limited to, marine propulsion, earth-moving, construction, and agricultural settings. As a non-limiting example, the engine  10  may be a marine engine. By utilizing the systems and methods disclosed herein, the monitoring system  50  may monitor parameters of the oil circulating through engines utilized in high power applications, such as the engine  10 , such that the monitoring device  56  receives oil for monitoring, without direct exposure to the high pressure and flow of oil circulating through the engine  10  and the lubrication system  12 , at a desired pressure and flow that is in compliance with the operational pressure and flow requirements of the monitoring device  56 . 
     In particular, the flow restrictor  58  of the monitoring system  50  is designed and configured to limit the flow of oil received by the monitoring device  56  based on the peak pressure at the first location  60  upstream of the cooler bypass  20  and the exit pressure at the second location  62  downstream of the oil cooler  32  (e.g. the dimensions of the flow restrictor  58  are appropriately designed based on the peak pressure and the pressure drop across the oil cooler  32 ). As a result, monitoring devices, such as the monitoring device  56 , having strict operational pressure and flow requirements are capable of being implemented in engines, such as the engine  10 , utilized in high power applications. 
     Additionally, the teachings of this disclosure can be employed such that the monitoring device  56  receives oil for monitoring while the oil continuously circulates through the engine  10  and the lubrication system  12  without any loss of oil during monitoring. For example, as the engine  10  is operating, the majority of the oil flowing from the pump  14  is supplied to the cooler bypass  20  via the supply flow path  22  while a portion of the oil is diverted therefrom to flow through the input conduit  52  to the monitoring device  56  at the desired pressure and flow provided by the flow restrictor  58  of the monitoring system  50 . After the oil circulates across the monitoring device  56  for monitoring the parameters of the oil, the oil subsequently flows through the output conduit  54  to the oil filter  40  for filtering the oil before continuing to flow to the engine  10 . In such a manner, substantially all of the oil supplied from the pump  14  is circulated to the engine  10  for lubricating and cooling, as the monitored oil circulates to the engine  10 , as well as the oil exiting the oil cooler  32 , via the oil filter  40 . This may be contrasted from other systems in which oil is diverted to the oil pan or sump after being monitored such that the engine receives less oil than initially supplied from the pump. 
     Moreover, in some embodiments, the monitoring system  50  is adapted for utilization on post-manufactured engines that include an oil cooler such as engines already in existence, which may have already been used in the field.  FIG. 5  illustrates a block diagram  500  of a sample sequence of steps which may be performed to provide a monitoring system to a post-manufactured engine that includes an oil cooler. As illustrated at block  510 , the dimension of the flow restrictor  58  of the monitoring system  50  is determined based on the peak pressure at the first location  60  upstream of the oil cooler  32  and the exit pressure at the second location  62  downstream of the oil cooler  32 . In some embodiments, the first location  60  is upstream of the cooler bypass  20 , which is disposed upstream of the oil cooler  32 . 
     The input conduit  52  of the monitoring system  50  is provided in fluid communication with the first location  60 , as illustrated in block  512 . In some embodiments, the input conduit  52  includes a input fitting, which is adapted to fluidly couple to the first location  60 . Further, the output conduit  54  of the monitoring system  50  is provided in fluid communication with the second location  62 , as illustrated in block  514 . In some embodiments, the output conduit  54  includes an output fitting, which is adapted to fluidly couple to the second location  62 .