DEVICE FOR DETECTING WEAR OF AN ELECTRICALLY RESISTIVE WEAR MEMBER

• US 20200132431A1
• Filed: 10/26/2018
• Published: 04/30/2020
• Est. Priority Date: 10/26/2018
• Status: Active Grant

• Current Assignee: Deere & Company
• Original Assignee: Deere & Company
• Inventors: Anderson, Noel W., Rhodes, Michael L.
• Granted Patent: US 11,549,797 B2
• Time in Patent Office: Days
• CPC Class Codes: G01B 7/18 using change in resistance
• CPC Class Codes: G01L 1/20 by measuring variations in ohmic resistance of solid materials or of electrically-conductive fluids of piezo-resistive materials G01L1/18; by making use of electrokinetic cells, i.e. liquid-containing cells wherein an electrical potential is produced or varied upon the application of stress
• CPC Class Codes: G01N 27/20 Investigating the presence of flaws
• CPC Class Codes: G01N 3/56 Investigating resistance to wear or abrasion

Abstract

A device for detecting wear of a wear member composed of electrically resistive material. The wear member comprises at least two electrodes separated from each other, where each electrode overlies, or is embedded in, an outer surface of the electrically resistive material. One of the electrodes is connected to a resistor at a measurement node to form a resistive voltage divider. A voltage measurement device measures a change in voltage at the measurement node, where the change is voltage is indicative of the degree of removal of resistive material from a face of the wear member and where the change in voltage is continuously variable and not limited to discrete wear levels.

Claims

1. A device for detecting wear of a wear member, the device comprising:

an electrically resistive material having a face for engaging a mechanical contact member and an outer surface separate from the face;

at least two electrodes overlying the outer surface of the electrically resistive material;

a resistor;

one of the electrodes is connected to the resistor at a measurement node to form a resistive voltage divider; and

a voltage measurement device measures a change in voltage at the measurement node where the change in voltage is indicative of the wear level or the degree of removal of resistive material from a face of the wear member, where the change in voltage is continuously variable and not limited to discrete wear levels.

2. The device according to claim 1 wherein the electrodes are embedded in the electrically resistive material.

3. The device according to claim 1 further comprising:

an analog-to-digital converter coupled to the measurement node;

a data storage device for storing reference data comprising reference measurement voltage versus a wear level of the wear member;

an electronic data processor adapted to determine the wear level or degree of removal of the resistive material from the face of the wear member based on an observed change in voltage at the measurement node with respect to an initial voltage or a reference voltage at the measurement node associated with an initial wear member with a new face without any resistive material yet removed.

4. The device according to claim 3 further comprising:

a user interface providing a visual indicator, an audible indicator or both to a user that is indicative of the determined wear level of determined degree of removal of resistive material from the face of the wear member, the user interface coupled to the electronic data processor via a communications interface and a data bus.

5. The device according to claim 1 further comprising:

the mechanical contact member having an engaging face that contacts and engages the face of the wear member to remove the electrically resistive material over time from the initial state of wear member to a partially worn state of the wear member, wherein a partially worn state of the wear member is associated with an observed voltage measurement within a first reference voltage measurement range between a first lower limit and a first upper limit.

6. The device according to claim 1 further comprising:

the mechanical contact member having an engaging face that contacts and engages the face of the wear member to remove the electrically resistive material over time from the initial state of wear member to a recommended replacement state of the wear member, wherein a recommended replacement state of the wear member is associated with an observed voltage measurement within a second reference voltage measurement range between a second lower limit and a second upper limit, wherein the second reference voltage range is lower than the first reference voltage range.

7. The device according to claim 1 further comprising:

the mechanical contact member having an engaging face that contacts and engages the face of the wear member to remove the electrically resistive material over time from the initial state of wear member to a fully worn state of the wear member, wherein the fully worn state of the wear member is associated with an observed voltage measurement within a third reference voltage measurement range between a third lower limit and a third upper limit, wherein the third reference voltage range is lower than the first reference voltage range and the second reference voltage range.

8. The device according to claim 1 wherein the at least two electrodes comprise a plurality of primary electrodes spaced apart from each other on the outer face and a secondary electrode on an opposite face;

each of the primary electrodes associated with a respective separate resistive zone between ones of the primary electrodes and the secondary electrode;

and further comprising;

a resistive network incorporating the resistor, the resistive network coupled to the primary electrode;

an analog multiplexer coupled to the primary electrodes via the resistive network to select respective ones of the primary electrodes or their respective measurement nodes;

a data storage device for storing reference data comprising reference measurement voltage versus a wear level of the wear member for each corresponding resistive zone;

an electronic data processor adapted to determine the wear level or degree of removal of the resistive material from the face of the wear member based on any observed change in voltage at the respective measurement nodes with respect to each initial voltage or each reference voltage for the corresponding resistive zone at the respective measurement node.

9. The device according to claim 8 wherein each resistive zone is associated with a separate wear level range and wherein there are at least two respective wear level ranges, where within each wear level range the wear level is continuously variable and not limited to discrete wear levels.

10. The device according to claim 8 further comprising:

a user interface providing a visual indicator, an audible indicator or both to a user that is indicative of the determined wear level of determined degree of removal of resistive material from the face of the wear member, the user interface coupled to the electronic data processor via a communications interface and a data bus.

11. A device for detecting wear of a wear member, the device comprising:

an electrically resistive material having a first face for engaging a first mechanical contact member and an outer surface separate from the first face;

a plurality of primary electrodes spaced apart from each other on the outer surface;

a secondary electrode on an opposite surface to the outer surface of the electrically resistive material;

a plurality of resistive zones separated from each other, each of the resistive zones extending in the electrically resistive material between ones of the primary electrodes and the secondary electrode;

a resistive network comprising resistive voltage dividers coupled to the primary electrodes at respective measurement nodes; and

a voltage measurement device measures a voltage change at one or more of the measurement nodes where each voltage change is indicative of a respective wear level or the respective degree of removal of resistive material from a face of the wear member, where the voltage change is continuously variable and not limited to discrete wear levels.

12. The device according to claim 11 wherein the electrically resistive material further comprises a second face opposite the first face on the electrically resistive material, where the second face is arranged for engaging a second mechanical contact member;

wherein the voltage measurement device is configured to measure a first wear level associated with the first surface of the wear member and a second wear level associated with the second surface of the wear member.

13. The device according to claim 12 wherein the first wear level of the first face is generally correlated to the second wear level of the second face.

14. The device according to claim 12 wherein the first wear level of the first face is independent of the second wear level of the second face.

15. The device according to claim 12 wherein:

an analog multiplexer is coupled to the primary electrodes via the resistive network to select respective ones of the primary electrodes or their respective measurement nodes;

a data storage device for storing reference data comprising reference measurement voltage versus a wear level of the wear member for each corresponding resistive zone;

an electronic data processor adapted to determine the first wear level or degree of removal of the resistive material from the first face of the wear member and to determine the second wear level or degree of removal of the resistive material from the second face of the wear member based on any observed change in voltage at the respective measurement nodes with respect to each initial voltage or each reference voltage for the corresponding resistive zone at the respective measurement node.

16. The device according to claim 11 wherein:

an analog multiplexer is coupled to the primary electrodes via the resistive network to select respective ones of the primary electrodes or their respective measurement nodes;

a data storage device for storing reference data comprising reference measurement voltage versus a wear level of the wear member for each corresponding resistive zone;

an electronic data processor adapted to determine the wear level or degree of removal of the resistive material from the first face of the wear member based on any observed change in voltage at the respective measurement nodes with respect to each initial voltage or each reference voltage for the corresponding resistive zone at the respective measurement node.

17. The device according to claim 11 wherein each resistive zone is associated with a separate wear level range and wherein there are at least two respective wear level ranges, where within each wear level range the wear level is continuously variable and not limited to discrete wear levels.