×

METHOD FOR OPERATING AN OIL FILTER SYSTEM

  • US 20140346119A1
  • Filed: 05/22/2014
  • Published: 11/27/2014
  • Est. Priority Date: 05/23/2013
  • Status: Active Application
First Claim
Patent Images

1. A method for operating an oil filter system for transmission oil of a transmission assembly having a clutch or a brake, as well as a filter circuit having at least one oil filter and a hydraulic pump with an electric drive or an electrically superimposed drive and controller, wherein the drive of the hydraulic pump is controlled and turned on by the controller, the method comprising the steps of:

  • providing a contamination model for indirectly determining an actual contamination level Va (%) of the transmission oil via a relationship
    Va (%)=Vstart(IW %)−

    A (%)+B (%)+C (%),whereinVstart (IW %) is a starting contamination value based on an initial original contamination value IW % that is freely selectable for an initial system startup during manufacture/final inspection,A (%) is an oil cleaning level percentage that is a function of a hydraulic pump flow rate,B (%) is an oil contamination level percentage that is a function of a clutch energy input, andC (%) is an oil contamination level percentage that is a function of a transmission performance;

    initializing the contamination model with the initial starting contamination value Vstart (IW %);

    decrementing the initial starting contamination value Vstart (IW %) by A (%) and incrementing Vstart (IW %) by B (%) and C (%) to compute the actual contamination level Va (%);

    defining a contamination level threshold value Vs (%) and comparing the contamination level threshold value Vs (%) with the actual contamination level Va (%);

    when the actual contamination level Va (%) exceeds the contamination level threshold value Va (%), switching the drive of the hydraulic pump on and controlling the drive of the hydraulic pump until the actual contamination level Va (%), as computed by decrementing with A (%) in the contamination model, is equal to or less than the contamination level threshold value Va (%) minus a fixed hysteresis value VH (%);

    storing the actual contamination level Va (%) in a nonvolatile memory of the controller; and

    using the stored actual contamination level Va in a subsequent system startup;

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×