1. A clearance measurement system, comprising:
a reference geometry disposed on a first object having an otherwise continuous surface geometry, wherein the otherwise continuous surface geometry comprises a circular structure extending along a plurality of blades that are independent from the reference geometry, wherein the reference geometry comprises a multi-level structure having a plurality of different levels relative to the otherwise continuous surface geometry, a plurality of reference geometries each having a different level relative to the otherwise continuous surface geometry, or a combination thereof;
a sensor disposed on a second object, wherein the sensor is configured to generate a first signal representative of a first sensed parameter from the first object and a second signal representative of a second sensed parameter from the reference geometry; and
a processing unit configured to process the first and second signals to estimate a clearance between the first and second objects based upon a measurement difference between the first and second sensed parameters, wherein the second signal representative of the second sensed parameter corresponding to reference geometry changes as a function of the clearance between the first and second objects, wherein the sensor system is configured to measure the clearance as the first object moves relative to the second object.
2. The system of claim 1, wherein the first object comprises a rotating member and the second object comprises a stationary member disposed about the rotating member in a turbine.
3. The system of claim 1, further comprising:
an excitation source configured to supply excitation signals to the sensor;
a phase detector configured to detect a plurality of reflected signals from respective ones of the first object and the reference geometry and to perform a plurality of phase measurements to determine a phase between each of the reflected signals and the respective excitation signals.
4. The system of claim 1, wherein the sensor is a capacitive probe, and the first and second sensed parameters are capacitances.
5. The system of claim 4, wherein the capacitive probe comprises at least two probe tips for measuring an axial and a radial clearance.
6. The system of claim 1, wherein the reference geometry comprises the plurality of reference geometries.
7. The system of claim 6, wherein each of the plurality of reference geometries comprises a different depth recessed below the otherwise continuous surface geometry.
8. The system of claim 1, wherein the reference geometry comprises the multi-level structure.
9. The system of claim 1, wherein the processing unit comprises a look-up table, or a calibration curve, or an analytical model, or a calculation, or combinations thereof for estimating the clearance between the first and second objects based upon the measurement difference between the first and second sensed parameters.
10. The system of claim 1, further comprising a clearance control unit coupled to the processing unit for controlling the clearance between the first and second objects based upon the clearance estimated by the processing unit.
11. A rotating machine, comprising:
a rotating component spaced apart from a stationary component, wherein the rotating component comprises a continuous surface in the direction of rotation of the rotating component;
a multi-level reference geometry disposed on the continuous surface of the rotating component, wherein the multi-level reference geometry comprises at least a first level and a second level different from the first level, and the first level and the second level are different from the continuous surface;
a sensor configured to generate first and second signals representative of first and second sensed parameters corresponding to the rotating component and different levels of the multi-level reference geometry, respectively, wherein the second signal representative of the second sensed parameter corresponding to the reference geometry changes as a function of the clearance between the rotating component and the stationary component; and
a processing unit configured to process the first and second signals to estimate a clearance between the rotating and stationary components based upon a measurement difference between the first and second sensed parameters and pre-determined depths of the different levels of the multi-level reference geometry.
12. The rotating machine of claim 11, wherein the sensor is disposed within the stationary component of the rotating machine.
13. The rotating machine of claim 11, wherein the rotating machine comprises a steam turbine, or a generator, or an electric motor, or a pump, or a compressor.
14. The rotating machine of claim 13, wherein the rotating component comprises a rotating bucket and the stationary component comprises a carrier disposed about the rotating bucket, and the rotating bucket comprises the continuous surface extending concentric with a plurality of blades.
15. The rotating machine of claim 11, wherein the sensor comprises a capacitive probe and the first and second sensed parameters comprise capacitance.
16. The rotating machine of claim 11, further comprising a plurality of reference geometries having dissimilar geometries from one another disposed on the continuous surface of the rotating component.
17. A method of measuring a clearance between a first object and a second object, comprising:
generating a first signal indicative of a first sensed parameter corresponding to the first object via a sensor disposed on the second object, wherein the sensor comprises at least two probe tips for measuring axial and radial clearances between the first and second objects, the first and second objects rotate relative to one another, and the first and second objects are generally circular at an interface between the first and second objects;
generating a second signal indicative of a second sensed parameter corresponding to a clearance reference disposed on a continuous circular surface of the first object via the sensor disposed on the second object, wherein the second signal indicative of the second sensed parameter corresponding to the clearance reference changes as a function of the clearance between the first object and the second object, and the clearance reference comprises a multi-level reference geometry with different levels relative to the continuous circular surface, a plurality of reference geometries each having a different level relative to the continuous circular surface, or a combination thereof;
processing the first and second signals to estimate the clearance between the first and second objects based upon a measurement difference between the first and second sensed parameters; and
controlling the clearance between the first and second objects based upon the estimated clearance between the first and second objects.
18. The method of claim 17, wherein generating the second signal comprises generating a signal corresponding to the clearance reference having a pre-determined depth.
19. The method of claim 17, wherein generating the second signal comprises generating a plurality of signals corresponding to the plurality of reference geometries.
20. The method of claim 17, wherein processing the first and second signals comprises detecting a plurality of reflected signals from respective ones of the first object and the clearance reference and performing a plurality of phase measurements to determine a phase between each of the reflected signals and corresponding excitation signals.
21. The method of claim 17, wherein generating the first and second signals comprises measuring first and second capacitance values as the first and second sensed parameters.
22. The rotating machine of claim 15, wherein the capacitive probe comprises at least two probe tips for measuring an axial and a radial clearance.
23. The method of claim 17, wherein generating the second signal indicative of the second sensed parameter corresponding to the clearance reference comprises generating the second signal that changes in response to the clearance between the first and second objects.
24. The method of claim 17, wherein the clearance reference comprises a recess in the continuous circular surface.
25. The method of claim 17, wherein measuring a clearance comprises measuring the clearance as the first object moves relative to the second object.
26. The method of claim 17, wherein the clearance reference comprises the multi-level reference geometry with different levels relative to the continuous circular surface.
27. A rotating machinery, comprising:
a rotating component spaced apart from a stationary component, wherein the rotating component comprises a continuously circular structure having a plurality of reference geometries interrupting the continuity of the continuously circular structure about an axis of rotation of the rotating component, wherein the plurality of reference geometries each having a different level relative to the continuously circular structure; and
a clearance measurement system coupled to the rotating component and to the stationary component, wherein the clearance measurement system is configured to convert direct current based capacitive measurements between the rotating and stationary components to time-varying capacitive measurements based on at least one of the plurality of reference geometries, wherein the time-varying capacitive measurements change as a function of the clearance between the rotating component and the stationary component, and the clearance measurement system is configured to estimate a clearance between the rotating and stationary components based on the time-varying capacitive measurements.
28. The rotating machinery of claim 27, wherein the plurality of reference geometries comprises a multi-level reference geometry having at least a first level and a second level different from the first level, wherein the first level and the second level are different from the continuously circular structure about the axis of rotation of the rotating component.
29. The system of claim 27, wherein the plurality of blades are concentric with and independent from the circular structure.
30. The system of claim 27, wherein each of the plurality of reference geometries is recessed into the continuously circular structure.
31. A system, comprising:
a rotatable structure having a plurality of blades and a circular structure disposed concentric with the plurality of blades, wherein the circular structure comprises a capacitive clearance reference having a multi-level reference geometry with different levels relative to a surface of the circular structure, a plurality of reference geometries each having a different level relative to the surface, or a combination thereof; and
a stationary structure concentric with the rotatable structure, wherein the capacitive clearance reference is configured to enable conversion of direct current based capacitive measurements between the rotatable and stationary structures to time-varying capacitive measurements.
32. The system of claim 31, comprising the multi-level reference geometry having a recess with different depths extending below the surface of the circular structure.
33. The system of claim 31, comprising the plurality of reference geometries each having a different recess with a different depth extending below the surface of the circular structure.
34. The system of claim 31, wherein a clearance system configured to provide an axial clearance measurement and a radial clearance measurement between the rotable and stationary structures.
35. The system of claim 31, wherein the plurality of blades are concentric with and independent from the circular structure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An apparatus comprising:
a coin sensing unit having
a substantially horizontal main face upon which coins can be deposited,
a coin sweeping arm configured to rotate in a substantially horizontal plane so as to sweep coins across the main face, and
a coin sensing apparatus configured to sense characteristics of a coin as it is swept across the main face;
a coin conveyor configured to receive coins from a coin exit of the coin sensing unit and to convey the coins in a substantially horizontal plane;
a rotary coin conveyor in a substantially vertical plane configured to convey coins from a first lower position to a second higher position;
wherein the coin sensing unit is configured to receive coins from the substantially vertical coin conveyor at the second higher position; and
wherein the substantially horizontal coin conveyor is configured to convey the coins to one of a plurality of coin hoppers located beneath the substantially horizontal plane of the coin conveyor.
2. An apparatus according to claim 1, wherein the main face of the coin sensing unit is substantially circular and the length of the sweeping arm is substantially equal to the radius of the main face.
3. An apparatus according to claim 1, wherein a leading face of the sweeping arm comprises a \u201cV\u201d profile in which coins are held in a fixed position relative to the sweeping arm and thus swept across the main face along a predictable path.
4. An apparatus according to claim 1, wherein the sensing unit is configured to cause a comparison between sensed characteristics of the coin and known genuine coin characteristics in order to validate the coin.
5. An apparatus according to claim 1, wherein the coin conveyor is configured to receive coins from the coin sensing unit and to convey the coins to one of a plurality of coin hoppers.
6. An apparatus according to claim 1, wherein the coin conveyor comprises a rotary conveyor configured to convey the coins along a looped path in said substantially horizontal plane.
7. An apparatus according to claim 1, wherein the coin conveyor comprises a plurality of individually controllable gates which are configured to open in response to an opening signal to selectively cause one or more coins being conveyed on the conveyor to fall into a selected one of a plurality of coin hoppers.
8. An apparatus according to claim 7, wherein each gate is connected to at least one hopper and wherein the gate which is opened for each particular coin is selected in response to a signal indicating sensed characteristics of the coin, thereby causing the coin to fall into the hopper connected to the opened gate.
9. An apparatus according to claim 7, wherein a solenoid is located adjacent to each gate to cause the gate to open or close in response to an opening or closing signal.
10. An apparatus according to claim 1, wherein the horizontal planes of the coin sensing unit and horizontal coin conveyor are at substantially the same vertical height.
11. An apparatus according to claim 1, wherein the substantially vertical coin conveyor is configured to convey coins along a substantially curved portion of a guide into a substantially horizontal plane on a substantially horizontal portion of the guide.
12. An apparatus according to claim 11, wherein the substantially vertical conveyor comprises a chain of coin conveying elements configured to convey coins along the guide.
13. An apparatus according to claim 11, configured to feed coins in a horizontal plane from the horizontal portion of the guide onto the main face of the coin sensing unit.
14. An apparatus according to claim 11, wherein the horizontal planes of the coin sensing unit, the horizontal coin conveyor and the guide are at substantially the same vertical height.
15. An apparatus according to claim 11, wherein the substantially vertical conveyor is configured to receive coins at the first lower position on an upper side of the conveyor and to convey the coins along the curved portion of guide until the coins are disposed on a lower side of the conveyor between the conveyor and the guide.
16. An apparatus according to claim 11, wherein the guide is static relative to the substantially vertical conveyor.
17. An apparatus for mounting in a gaming or vending or self-operated payment machine, comprising:
a coin sensing unit having
a substantially horizontal main face upon which coins can be deposited,
a coin sweeping arm configured to rotate in a substantially horizontal plane so as to sweep coins across the main face, and
a coin sensing apparatus configured to sense characteristics of a coin as it is swept across the main face;
a coin conveyor configured to receive coins from a coin exit of the coin sensing unit and to convey the coins in a substantially horizontal plane;
at least one coin hopper having a first normal position;
at least one other component having a first normal position corresponding to the first normal position of the coin hopper; and
a slider mountable to the machine for sliding the at least one coin hopper and the at least one other component out of the gaming or vending machine to a second outward position;
wherein the at least one coin hopper can be slid independently of the at least one other component.
18. An apparatus according to claim 17, comprising:
a sensor for sensing the weight of the at least one coin hopper; and
a lock configured to prevent the at least one coin hopper from leaving the first normal position when the at least one other component is not in its first normal position if the weight of the at least one hopper exceeds a predetermined value.
19. An apparatus according to claim 17, wherein the at least one other component comprises a housing in which the at least one coin hopper is located in the first position during normal operation of the apparatus in the machine.
20. An apparatus according to claim 17, wherein the main face of the coin sensing unit is substantially circular and the length of the sweeping arm is substantially equal to the radius of the main face.
21. An apparatus according to claim 17, wherein a leading face of the sweeping arm comprises a \u201cV\u201d profile in which coins are held in a fixed position relative to the sweeping arm and thus swept across the main face along a predictable path.
22. An apparatus according to claim 17, wherein the sensing unit is configured to cause a comparison between sensed characteristics of the coin and known genuine coin characteristics in order to validate the coin.
23. An apparatus according to claim 17, wherein the coin conveyor is configured to receive coins from the coin sensing unit and to convey the coins to one of a plurality of coin hoppers.
24. An apparatus according to claim 17, wherein the coin conveyor comprises a rotary conveyor configured to convey the coins along a looped path in said substantially horizontal plane.
25. An apparatus according to claim 17, wherein the coin conveyor comprises a plurality of individually controllable gates which are configured to open in response to an opening signal to selectively cause one or more coins being conveyed on the conveyor to fall into a selected one of a plurality of coin hoppers.
26. An apparatus according to claim 25, wherein each gate is connected to at least one hopper and wherein the gate which is opened for each particular coin is selected in response to a signal indicating sensed characteristics of the coin, thereby causing the coin to fall into the hopper connected to the opened gate.
27. An apparatus according to claim 25, wherein a solenoid is located adjacent to each gate to cause the gate to open or close in response to an opening or closing signal.
28. An apparatus according to claim 17, wherein the horizontal planes of the coin sensing unit and horizontal coin conveyor are at substantially the same vertical height.