Method and apparatus for on-sine monitoring of wear in machinery

Claim 1

A device for producing an electrical signal which is proportional to the concentration of ferromagnetic particulate material in a fluid stream, said device comprising, in combination: a sensing coil arranged to form the inductance coil of and connected to a radio frequency oscillator arranged to produce an electrical signal at a base frequency; magnetic trap means for producing a magnetic field; and support means for supporting said sensing coil and said magnetic trap measn in juxtaposition to one another such that, when said coil is disposed within or proximate said fluid stream and electrically connected to radio frequency oscillator, energization of said magnetic trap measn causes ferromagnetic particulate material proximate said coil to be attracted toward said coil resulting in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream.

Claim 2

A device for producing an electrical signal which is proportional to the concentration of ferromagnetic particulate material in a fluid stream, said device comprising, in combination: a sensing coil arranged to form the inductance coil of and connected to a radio frequency oscillator arranged to produce an electrical signal at a base frequency; magnetic trap means for producing a magnetic field; and support means for supporting said sensing coil and said magnetic trap measn in juxtaposition to one another such that, when said coil is disposed within or proximate said fluid stream and electrically connected to radio frequency oscillator, energization of said magnetic trap measn causes ferromagnetic particulate material proximate said coil to be attracted toward said coil resulting in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream.

Claim 9

A device for producing an electrical signal which is proportional to the concentration of ferromagnetic particulate material in a fluid, said device comprising, in combination: a housing having a fluid passage extending therethrough; a radio frequency oscillator for producing an electrical signal at a predetermined base frequency, said oscillator having an inductance coil disposed in said housing in coaxial relation with respect to said passage; magnetic trap means disposed in said housing in electrically insulated relation with respect to said inductance coil, said magnetic trap means being arranged to produce a magnetic field about said inductance coil such that energization of said magnetic trap means causes ferromagnetic particulate material in said passage and proximate said coil to be attracted toward said coil and results in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream.

Claim 10

A device for producing an electrical signal which is proportional to the concentration of ferromagnetic particulate material in a fluid, said device comprising, in combination: a housing having a fluid passage extending therethrough; a radio frequency oscillator for producing an electrical signal at a predetermined base frequency, said oscillator having an inductance coil disposed in said housing in coaxial relation with respect to said passage; magnetic trap means disposed in said housing in electrically insulated relation with respect to said inductance coil, said magnetic trap means being arranged to produce a magnetic field about said inductance coil such that energization of said magnetic trap means causes ferromagnetic particulate material in said passage and proximate said coil to be attracted toward said coil and results in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream.

Claim 15

A device as defined in calim 12, said quantity being the ratio of the magnitude of said deviation to the duration of said deviation.

Claim 16

A device as defined in calim 12, said quantity being the ratio of the magnitude of said deviation to the duration of said deviation.

Claim 19

An apparatus for monitoring to rate if wear of a machine emeploying a lubricating fluid for lubricating ferromagnetic components which produce ferromagnetic particulate wear debris during operation, said apparatus comprising, in combination: a detector for producing an electrical signal proportional to the concentration of ferromagnetic particulate material in said fluid, said detector including a housing a fluid passage extending therethrough a radio frequency oscillator for producing an electrical signal at a predetermined base frequency, said oscillator having an inductance coil disposed in said housing in coaxial relation with respect to said passage, magnetic trap means disposed in said housing in electrically insulates relation with respect to said inductance coil, said magnetic trap means being arranged to produce a magnetic field about said inductance coil such that energization of said magnetic trap means causes ferromagnetic particualte material in said passage and proximate said coil to be attracted toward said coil and results in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream; control means for energizing and de-energizing said magnetic trap means at predetermined timed intervals; means for determining, at the end of each said predetermined timed interval, a quantity linearly related to the concentration of ferromagnetic partoculate material in fluid passed through said detector, determining the rate of change of said quantities and activating an alarm means when the rate of change of said quantity exceeds a predetermined threshold value.

Claim 20

An apparatus for monitoring to rate if wear of a machine emeploying a lubricating fluid for lubricating ferromagnetic components which produce ferromagnetic particulate wear debris during operation, said apparatus comprising, in combination: a detector for producing an electrical signal proportional to the concentration of ferromagnetic particulate material in said fluid, said detector including a housing a fluid passage extending therethrough a radio frequency oscillator for producing an electrical signal at a predetermined base frequency, said oscillator having an inductance coil disposed in said housing in coaxial relation with respect to said passage, magnetic trap means disposed in said housing in electrically insulates relation with respect to said inductance coil, said magnetic trap means being arranged to produce a magnetic field about said inductance coil such that energization of said magnetic trap means causes ferromagnetic particualte material in said passage and proximate said coil to be attracted toward said coil and results in a deviation of the frequency of said signal from said base frequency proportional to the concentration of ferromagnetic particulate material in said fluid stream; control means for energizing and de-energizing said magnetic trap means at predetermined timed intervals; means for determining, at the end of each said predetermined timed interval, a quantity linearly related to the concentration of ferromagnetic partoculate material in fluid passed through said detector, determining the rate of change of said quantities and activating an alarm means when the rate of change of said quantity exceeds a predetermined threshold value.

Claim 25

A method of determining a quantity related to the concentratoin of ferromagnetic material in a fluid, comprising the steps of: (a) passing a sample of said fluid through a fluid conduit; (b) electromagnetically trapping ferromagnetic particulate material at a predetermined site in said fluid conduit at which an inductance coil of a radio frequency oscillator is coaxially disposed; (c) determining the deviation, during said electromagnetically trapping step, of the frequency of the output signal of said oscillator from a reference signal; and (d) determining the ratio of said deviation to the duration of said deviation, said ratio being linearly proportional to the concentration of said ferromagnetic particulate material in said fluid.

Claim 26

A method of determining a quantity related to the concentratoin of ferromagnetic material in a fluid, comprising the steps of: (a) passing a sample of said fluid through a fluid conduit; (b) electromagnetically trapping ferromagnetic particulate material at a predetermined site in said fluid conduit at which an inductance coil of a radio frequency oscillator is coaxially disposed; (c) determining the deviation, during said electromagnetically trapping step, of the frequency of the output signal of said oscillator from a reference signal; and (d) determining the ratio of said deviation to the duration of said deviation, said ratio being linearly proportional to the concentration of said ferromagnetic particulate material in said fluid.

Claim 33

A method of determining the degree of wear of a machine having ferromagnetic components subjected to wear during operation resulting in the production of ferromagnetic particulate material, said machine having a lubrication system utilizing a lubrication fluid, in which said ferromagnetic particulate material becomes entrained, for lubricating said components, said method comprising the steps of: (a) passing a sample of said fluid through a fluid conduit having (i) an electromagnet concentrically disposed thereabout at a predetermined site thereof and (ii) an inductance coil of an oscillator circuit coaxially disposed with respect to said conduit at said site; (b) energizing said electromagnet to trap ferromagnetic particulate material at said site; (c) activating a timing means to determine a trapping interval; (d) counting the number of cycles of the signal of said oscillator circuit which occur within said trapping interval; (e) deactivating said timing means when said count reaches a predetermined value; (f) de-energizing said electromagnet; (g) determining the ratio of said count to said trapping interval; (h) repeating steps (a) to (e) at fixed predetermined time intervals; and (i) determining the rate of change of said ratio and activating an alarm means if said rate of change exceeds a predetermined threshold level.

Claim 34

A method of determining the degree of wear of a machine having ferromagnetic components subjected to wear during operation resulting in the production of ferromagnetic particulate material, said machine having a lubrication system utilizing a lubrication fluid, in which said ferromagnetic particulate material becomes entrained, for lubricating said components, said method comprising the steps of: (a) passing a sample of said fluid through a fluid conduit having (i) an electromagnet concentrically disposed thereabout at a predetermined site thereof and (ii) an inductance coil of an oscillator circuit coaxially disposed with respect to said conduit at said site; (b) energizing said electromagnet to trap ferromagnetic particulate material at said site; (c) activating a timing means to determine a trapping interval; (d) counting the number of cycles of the signal of said oscillator circuit which occur within said trapping interval; (e) deactivating said timing means when said count reaches a predetermined value; (f) de-energizing said electromagnet; (g) determining the ratio of said count to said trapping interval; (h) repeating steps (a) to (e) at fixed predetermined time intervals; and (i) determining the rate of change of said ratio and activating an alarm means if said rate of change exceeds a predetermined threshold level.

Claim 35

A method of determining the effective means particle size of ferromagnetic wear debris in a lubricating fluid, comprising the steps of: (a) passing a sample of said fluid through a fluid conduit having an electromagnet associated therewith for trapping within said conduit ferromagnetic wear debris in said fluid and a detector for producing an output signal proportional to the concentration of ferromagnetic wear debris in said lubricating fluid at said trapping site; (b) determining the value of the current passing through said electromagnet at which the output of said detector is zero; (c) converting said value of said current to a number indicative of the mean particle size of said ferromagnetic wear debris.

Claim 36

A method of determining the effective means particle size of ferromagnetic wear debris in a lubricating fluid, comprising the steps of: (a) passing a sample of said fluid through a fluid conduit having an electromagnet associated therewith for trapping within said conduit ferromagnetic wear debris in said fluid and a detector for producing an output signal proportional to the concentration of ferromagnetic wear debris in said lubricating fluid at said trapping site; (b) determining the value of the current passing through said electromagnet at which the output of said detector is zero; (c) converting said value of said current to a number indicative of the mean particle size of said ferromagnetic wear debris.