Stable, reliable capacitive oil deterioration and level sensor
First Claim
1. A reliable capacitive fluid deterioration and level sensing system comprising:
- a housing member comprising of an outer conductive shielding member, said shielding member having an inner surface defining a ground electrode, wherein the conductive shielding member precludes interference by adjacent metallic structures, said shielding member having at least one inlet port for a fluid, the housing member further having a threaded outer surface adapted to be threaded to a fluid container;
a conductive inner member with an outer surface defining a measuring electrode, said inner member being secured within said housing member and spaced from the shielding member by an insulating material to allow the fluid from the inlet port to occupy said space, such that said ground electrode and said measuring electrode define a fluid deterioration and level sensor variable capacitor;
said outer conductive shielding member at least partially extending over the outer end of said conductive inner member;
said shielding member substantially enclosing said conductive inner member and extending over the greater portion of and more than half of the combined areas of said measuring electrode and the gap between electrodes, both as viewed from the sides and as viewed from the outer end of said conductive inner member;
an electrical connector structure adapted to provide an electrical interface; and
electronics positioned within said housing member, said electronics being electrically connected to said fluid deterioration and level sensor capacitor, and said electrical connector structure, said electronics being adapted to generate a fluid deterioration output signal and a fluid level output signal employing said fluid deterioration and level sensor capacitor, and to provide said signals to the electrical connector structure.
1 Assignment
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Accused Products
Abstract
A reliable capacitive oil deterioration and level sensor has a conductive housing member that includes a conductive shielding member defining a ground electrode, and a conductive inner member defining a measuring electrode. The shielding member protects the sensor from moving objects that could adversely affect its performance. The housing member is adapted to provide a fluidic connection between an oil container and a space between the ground electrode and the measuring electrode. The sensor also includes electronics adapted to employ this capacitor geometry to generate signals indicative of a degree of deterioration and a level of the oil within the gap. The electronics further include at least one isolating capacitor to eliminate a flow of current between the electrodes that may cause a build up of material on the two electrodes that define the capacitor. This build up of unwanted material may cause an undesirable effect in the sensor output signal.
19 Citations
20 Claims
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1. A reliable capacitive fluid deterioration and level sensing system comprising:
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a housing member comprising of an outer conductive shielding member, said shielding member having an inner surface defining a ground electrode, wherein the conductive shielding member precludes interference by adjacent metallic structures, said shielding member having at least one inlet port for a fluid, the housing member further having a threaded outer surface adapted to be threaded to a fluid container;
a conductive inner member with an outer surface defining a measuring electrode, said inner member being secured within said housing member and spaced from the shielding member by an insulating material to allow the fluid from the inlet port to occupy said space, such that said ground electrode and said measuring electrode define a fluid deterioration and level sensor variable capacitor;
said outer conductive shielding member at least partially extending over the outer end of said conductive inner member;
said shielding member substantially enclosing said conductive inner member and extending over the greater portion of and more than half of the combined areas of said measuring electrode and the gap between electrodes, both as viewed from the sides and as viewed from the outer end of said conductive inner member;
an electrical connector structure adapted to provide an electrical interface; and
electronics positioned within said housing member, said electronics being electrically connected to said fluid deterioration and level sensor capacitor, and said electrical connector structure, said electronics being adapted to generate a fluid deterioration output signal and a fluid level output signal employing said fluid deterioration and level sensor capacitor, and to provide said signals to the electrical connector structure. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A reliable capacitive fluid deterioration and level sensing assembly comprising:
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a housing member having a threaded outer surface adapted to be threaded to a fluid container;
an outer conductive cylindrical member secured to said housing member, said outer conductive cylindrical member defining a ground electrode, and further having at least one inlet port for a fluid;
an inner conductive cylindrical member defining a measuring electrode and secured within said housing member, the inner cylindrical member being spaced from the outer cylindrical member to allow the fluid to occupy said space, such that the ground electrode and the measuring electrode define a fluid deterioration and level sensor capacitor; and
a shielding structure secured to said outer conductive cylindrical member to substantially enclose the inner electrode except for fluid flow openings, and extending over substantially more than half of the area of the inner electrode and the gap between electrodes at the sides and at the outer end of said inner electrode, said cylindrical members having a control axis and said shielding structure extending inwardly over one end of said measuring electrode toward said axis, wherein the shielding structure precludes interference by adjacent metallic structures, thereby permitting reliable operation of the fluid deterioration and level sensor capacitor. - View Dependent Claims (12, 13, 14, 15, 16)
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17. A reliable capacitive fluid deterioration and level sensing assembly comprising:
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a housing member having a threaded outer surface adapted to be threaded to a fluid container;
an outer conductive member secured to said housing member, said outer conductive member defining a ground electrode, and further having at least one inlet port for a fluid;
an inner conductive member defining a measuring electrode and secured within said housing member, the inner member being spaced from the outer member to allow the fluid to occupy said space, such that the ground electrode and the measuring electrode define a fluid deterioration and level sensor capacitor; and
a shielding structure secured to said outer conductive member to substantially enclose the inner electrode except for fluid flow openings, and extending over substantially more than half of the area of the inner electrode and the gap between electrodes as viewed from the sides and as viewed from the outer end of said inner electrode, wherein the shielding structure precludes interference by adjacent metallic structures, thereby permitting reliable operation of the fluid deterioration and level sensor capacitor. - View Dependent Claims (18, 19, 20)
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Specification