WO2013028054A1 - Method and apparatus for a magnetically coupled eddy- current dynamometer - Google Patents
Method and apparatus for a magnetically coupled eddy- current dynamometer Download PDFInfo
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- WO2013028054A1 WO2013028054A1 PCT/MY2012/000103 MY2012000103W WO2013028054A1 WO 2013028054 A1 WO2013028054 A1 WO 2013028054A1 MY 2012000103 W MY2012000103 W MY 2012000103W WO 2013028054 A1 WO2013028054 A1 WO 2013028054A1
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- rotating machine
- shaft
- dynamometer
- induction electromagnet
- magnetically coupled
- Prior art date
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
- G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
- G01L3/16—Rotary-absorption dynamometers, e.g. of brake type
- G01L3/22—Rotary-absorption dynamometers, e.g. of brake type electrically or magnetically actuated
Definitions
- the present invention relates to the field of rotating machinery torque measurement devices. More particularly the present invention relates to the field of absorption type dynamometers. Most particularly the present invention relates to a magnetically coupled eddy-current dynamometer.
- a dynamometer or "dyno" for short is a device for measuring force, moment of force (torque), or power.
- torque moment of force
- power the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed (RPM).
- a dynamometer can also be used to determine the torque and power required to operate a driven machine such as a pump. In that case, a motoring or driving dynamometer is used.
- a dynamometer that is designed to be driven is called an absorption or passive dynamometer.
- a dynamometer that can either drive or absorb is called a universal or active dynamometer.
- a dynamometer 1 consists of an absorption (or absorber/driver) unit, and usually includes a means for measuring torque 4, 5 and rotational speed.
- An absorption unit consists of some type of rotor 7 in a housing 6. The rotor 7 is coupled to the engine or other equipment under test 1 and is free to rotate at whatever speed is required for the test. Some means is provided to develop a braking torque between the dynamometer's rotor 7 and housing 6.
- the means for developing torque can be frictional, hydraulic, electromagnetic etc. according to the type of absorption/driver unit.
- One means for measuring torque is to mount the dynamometer housing 6 so that it is free to turn except that it is restrained by a torque arm 4.
- the housing 6 can be made free to rotate by using trunnions 8 connected to each end of the housing 6 to support the dynamometer in pedestal mounted trunnion bearings.
- the torque arm 4 is connected to the dynamometer housing 6 and a weighing scale 5 is positioned so mat II mecisui tjs me IUI UB cAcrted by the dynamometer housing 6 in attempting to rotate.
- the torque is the force indicated by the scales 5 multiplied by the length of the torque arm measured from the center of the dynamometer.
- a load cell transducer can be substituted for the scales 5 in order to provide an electrical signal that is proportional to torque.
- Another means for measuring torque is to connect the engine 1 to the dynamometer through a torque sensing coupling or torque transducer.
- a torque transducer provides an electrical signal that is proportional to torque.
- dynamometers are devices used for testing of engines and motors. In general, they consist of a controllable load coupled to the driving power source (i.e. a motor or engine). Typically the load and speed of the power source are measured. Additionally the dynamometer is often used as a means of controlling the speed or torque of the power source such as in the tuning of the electronic fuel injection system of an internal combustion engine.
- the present invention discloses an electromagnetic coupling of a rotating machine whose torque-speed characteristics are, to be determined, to an absorption type dynamometer. More particularly the present invention provides an eddy-current dynamometer that dispenses with the need to physically couple said dynamometer to the shaft of aforementioned rotating machine and thus facilitating the rapid testing of multiple rotating machines by inherently facilitating the rapid removal and replacement of the rotating machine. The dispensing of the need to physically couple said dynamometer to the shaft of aforementioned rotating machine also eliminates the requirement of shaft alignment as is observed in conventional eddy-current type dynamometers.
- an apparatus for an electromagnetically coupled eddy-current dynamometer more particularly the dynamometer is magnetically coupled to a shaft of a rotating machine such as an engine or motor.
- the magnetically coupled dynamometer apparatus of the present invention comprising of: a first portion that includes a conductive disc mounted on a rotating shaft of a rotating machine; and a second portion that includes: em iiiuuuiiui i eieuiiumcjgnet that serves to generate a magnetic field when alternating electrical current is fed into it, such that when the magnetic flux lines of the generated magnetic field links and cuts the area of the revolving disc, eddy currents are generated on the disc due to the motion of the disc, the generation of the eddy currents on the disc in turn leads to the generation of a torque on the disc that opposes the rotation of the disc due to the motion of the rotating machine shaft; the induced eddy currents consequently producing another magnetic field and the interaction between the magnetic
- Figure 1 is a diagram illustrating a side view of a conventional absorption type eddy current dynamometer of the prior art
- Figure 2 is a diagram illustrating the exploded view of a preferable embodiment of the magnetically coupled dynamometer of the present invention
- Figure 3 is a diagram illustrating the counter-torques produced on the disk of a preferable embodiment of the magnetically coupled dynamometer of the present invention
- Figure 4 is a diagram illustrating the assembled side view of a preferable embodiment of the magnetically coupled dynamometer of the present invention.
- nyure o is a uiayram niusiraurig the front-view of a preferable embodiment of the magnetically coupled dynamometer of the present invention.
- an apparatus of the magnetically coupled eddy-current dynamometer 10 of the present invention that includes a first portion 10a and a second portion 10b.
- the first portion 10a of the apparatus of aforementioned magnetically coupled eddy-current dynamometer 10a of the present invention includes a conductive disk 40 that is perforated in the centre to enable it to be secured fixedly by appropriate securing means to a shaft 30 of a rotating machine 20 whose torque speed characteristics are to be determined.
- the second portion 10b of the magnetically couple eddy current dynamometer 10 of the present invention includes a receptacle 100 (not shown) that houses an induction electromagnet 50 that comprises of a conductive coil 50a (not shown) wound around a ferromagnetic core 50b (not shown); a load cell 60; and a speed sensor 70.
- the second portion 10b further including a base 80 that serves to support the rotating machine 20 with its shaft 30 fitted with the conductive disc 40 of the first portion 10a and the induction electromagnet 50, the load cell 60 and speed sensor 70.
- the rotating machine 20 conductive disc 40 of the first portion 10a is placed in close proximity to the second portion 10b.
- the induction electromagnet 50, the load cell 60 and the speed sensor 70 of the second portion 10b of the eddy-current dynamometer 10 of the present invention are housed in the receptacle 100 (not shown) such that when the induction electromagnet 50 is fed an alternating electrical current, the resulting magnetic flux lines of the magnetic field produced by the alternating current that flows through the conductive coil of the induction electromagnet 50 links and cuts through the area of the conductive disc 40 of the first portion 10a of aforementioned magnetically coupled eddy current dynamometer 10.
- the rotating machine 20 When the rotating machine 20 is activated, its shaft 30 and the fitted conductive disc 40 of the first portion 10a of the magnetically coupled dynamometer of the present invention rotate at a fixed velocity.
- the rotating of the conductive disc 40 along with the shaft 30 of the rotating machine 10 cuts the magnetic flux lines produced by the magnetic field of the induction electromagnet 50 and consequently results in the induction of eddy currents on the surface of aforementioned conductive disc 40.
- the induced eddy-currents on the surface of aforementioned conductive disc 40 causes the disc 40 to experience a counter-torque in the presence of the magnetic field of the induction electromagnet 50 that opposes the torque applied to rotate the disc 40 along the direction of rotation of the shaft 30 of the rotating machine 20.
- the eddy-currents induced on the surface of aforementioned conductive disc 40 of the magnetically coupled eddy-current dynamometer 10 of the present invention produce another magnetic field that interacts with the magnetic field of the induction electromagnet 50 to induce a force that acts on said induction electromagnet 50.
- the load cell 60 and the induction electromagnet 50 are housed within the receptacle 100 (not shown) of the second portion 10b of the magnetically coupled eddy current dynamometer 10 of the present invention such that a load cell 60 is configured to provide a measure of the force acting on aforementioned induction electromagnet 50.
- a load cell 60 is a transducer that is used to convert a force into a electrical signal. This conversion is indirect and happens in two stages. merit, the force being sensed deforms a strain gauge.
- the strain gauge measures the deformation (strain) as an electrical signal, because the strain changes the effective electrical resistance of the wire.
- a load cell 60 usually includes four strain gauges in a Wheatstone bridge configuration and provides an electrical signal output is typically in the order of a few milli-volts and requires amplification by an instrumentation amplifier before it can be used.
- the load cell 60 as configured in arrangement in the receptacle of the second portion 10b of the eddy-current dynamometer 10 of the present invention provides an electrical output signal which is a measure of the torque experienced by the conductive disc 40 due to the rotation of the shaft 30 of the rotating machine 20.
- This electrical signal is fed to a work station via a data acquisition unit, the workstation including an algorithm to compute the numerical value of the torque experienced by the conductive disc 40 due to the rotation of the rotating shaft 30 in an area of its memory.
- the second portion 10b of the magnetically coupled eddy current dynamometer 10 of the present invention further includes a speed sensor 70 to provide a measure of the rotational speed of the revolving shaft 30 of the rotating machine 20.
- the second portion 10b includes a pair of induction electromagnets 50.
- a first portion 10a of aforementioned magnetically coupled dynamometer 10 that includes a conductive disc 40 on a shaft 30 of a rotating machine 20 under test and activating rotation of the rotating machine 20 under test in close proximity to a second portion 10b of the magnetically coupled u yncii T iui i ifc!it!i i u ui Li ic present invention that includes an induction electromagnet 50, a load cell 60 and a speed sensor 70;
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Force Measurement Appropriate To Specific Purposes (AREA)
Abstract
The present invention provides a magnetically coupled dynamometer (10) that dispenses with the need to physically couple said dynamometer (10) to the shaft (30) of aforementioned rotating machine (20) and facilitate the rapid testing of multiple rotating machines (20) by inherently facilitating the rapid removal and replacement of a rotating machine (20). The magnetically coupled dynamometer (10) apparatus of the present invention comprising of a first portion (10a) that includes a conductive disk (40) mounted on a rotating shaft (30) of a rotating machine (20) that is placed in close proximity to a second portion (10b) that includes an induction electromagnet (50), a load cell (60) configured to provide a measure of the force acting on the induction electromagnet (50) due to the interaction of the magnetic fields of the disk (40) and the induction electromagnet (50) and provides a measure of the torque generated by the rotating shaft (30) of the rotating machine (20), a speed sensor (70) configured to provide a measure of the rotational speed of the rotating machine's shaft (30) and a base (80) that serves to support the rotating machine (20) fitted with the first portion (10a) and the induction electromagnet (50), load cell (60) and the speed sensor (70).
Description
Mt I HUU AND A CAKA I US FOR A MAGNETICALLY COUPLED EDDY- CURRENT DYNAMOMETER
The present invention relates to the field of rotating machinery torque measurement devices. More particularly the present invention relates to the field of absorption type dynamometers. Most particularly the present invention relates to a magnetically coupled eddy-current dynamometer.
BACKGROUND TO THE INVENTION According to the online encyclopedia, Wikipedia, a dynamometer or "dyno" for short is a device for measuring force, moment of force (torque), or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed (RPM).
A dynamometer can also be used to determine the torque and power required to operate a driven machine such as a pump. In that case, a motoring or driving dynamometer is used. A dynamometer that is designed to be driven is called an absorption or passive dynamometer. A dynamometer that can either drive or absorb is called a universal or active dynamometer.
With reference to figure 1 (Prior Art), a dynamometer 1 consists of an absorption (or absorber/driver) unit, and usually includes a means for measuring torque 4, 5 and rotational speed. An absorption unit consists of some type of rotor 7 in a housing 6. The rotor 7 is coupled to the engine or other equipment under test 1 and is free to rotate at whatever speed is required for the test. Some means is provided to develop a braking torque between the dynamometer's rotor 7 and housing 6. The means for developing torque can be frictional, hydraulic, electromagnetic etc. according to the type of absorption/driver unit.
One means for measuring torque is to mount the dynamometer housing 6 so that it is free to turn except that it is restrained by a torque arm 4. The housing 6 can be made free to rotate by using trunnions 8 connected to each end of the housing 6 to support the dynamometer in pedestal mounted trunnion bearings. The torque arm 4 is connected to the dynamometer housing 6 and a weighing scale 5 is positioned so
mat II mecisui tjs me IUI UB cAcrted by the dynamometer housing 6 in attempting to rotate. The torque is the force indicated by the scales 5 multiplied by the length of the torque arm measured from the center of the dynamometer. A load cell transducer can be substituted for the scales 5 in order to provide an electrical signal that is proportional to torque.
Another means for measuring torque is to connect the engine 1 to the dynamometer through a torque sensing coupling or torque transducer. A torque transducer provides an electrical signal that is proportional to torque.
Most generally, dynamometers are devices used for testing of engines and motors. In general, they consist of a controllable load coupled to the driving power source (i.e. a motor or engine). Typically the load and speed of the power source are measured. Additionally the dynamometer is often used as a means of controlling the speed or torque of the power source such as in the tuning of the electronic fuel injection system of an internal combustion engine.
In general coupling of a rotating shaft to a dynamometer or other load is performed by physically connecting two shafts, one form the power source (e.g. a motor) the other from the power sink (e.g. a pump, fan, compressor or dynamometer). This process requires either careful alignment of the shafts, or the use of a coupling system which allows misalignment (eg. belts and pulleys, universal joints, constant velocity (CV) joints or dedicated "couplers" of various designs).
The requirement of careful alignment between a dynamometer, more specifically an eddy current dynamometer to a prime mover such as an Engine under test or Machine under test stems from the fact that misalignment between an eddy current dynamometer and the engine or rotating machinery under test results in, inaccurate torque measurement of the engine or rotating machinery under test.
Specifically when there is a misalignment between the shaft of an engine or rotating machine under test with respect to a shaft of an eddy-current dynamometer, there will be an excessive force experienced by the shaft of the dynamometer, consequently resulting in an erroneous torque measurement.
in aaaiiion xo xne aDove, me requirement for highly accurate alignment between the shafts of an engine under test or rotating machinery under test and the shaft of an eddy-current dynamometer, is time consuming and does not allow for the rapid testing of a large number of rotating machinery.
SUMMARY OF THE INVENTION
The following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is not intended to identify key/critical elements of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.
The present invention discloses an electromagnetic coupling of a rotating machine whose torque-speed characteristics are, to be determined, to an absorption type dynamometer. More particularly the present invention provides an eddy-current dynamometer that dispenses with the need to physically couple said dynamometer to the shaft of aforementioned rotating machine and thus facilitating the rapid testing of multiple rotating machines by inherently facilitating the rapid removal and replacement of the rotating machine. The dispensing of the need to physically couple said dynamometer to the shaft of aforementioned rotating machine also eliminates the requirement of shaft alignment as is observed in conventional eddy-current type dynamometers. In one aspect of the present invention, there is provided an apparatus for an electromagnetically coupled eddy-current dynamometer, more particularly the dynamometer is magnetically coupled to a shaft of a rotating machine such as an engine or motor. The magnetically coupled dynamometer apparatus of the present invention comprising of: a first portion that includes a conductive disc mounted on a rotating shaft of a rotating machine; and a second portion that includes:
em iiiuuuiiui i eieuiiumcjgnet that serves to generate a magnetic field when alternating electrical current is fed into it, such that when the magnetic flux lines of the generated magnetic field links and cuts the area of the revolving disc, eddy currents are generated on the disc due to the motion of the disc, the generation of the eddy currents on the disc in turn leads to the generation of a torque on the disc that opposes the rotation of the disc due to the motion of the rotating machine shaft; the induced eddy currents consequently producing another magnetic field and the interaction between the magnetic field produced by the eddy currents and the magnetic field resulting from the flow of current in the induction electromagnet causes a force to act on the induction electromagnet; a load cell configured to provide a measure of the force acting on the induction electromagnet due to the interaction of the magnetic fields of the conductive disc and the induction electromagnet and hence provide a measure of the torque generated by the rotating shaft of the rotating machine; a speed sensor configured to provide a measure of the rotational speed of the rotating machine's shaft; and a base that serves to support the rotating machine fitted with the first portion and the induction electromagnet, load cell and the speed sensor.
In another aspect of the present invention there is provided a method of magnetically coupling an apparatus for the measurement of the torque and speed of a, rotating machine. The method comprising the steps of:
1. Mounting a first portion of aforementioned magnetically coupled dynamometer that includes a conductive disc on a shaft of a rotating machine under test and activating rotation of the rotating machine under test, in close proximity to a second portion of the magnetically coupled dynamometer that includes an induction electromagnet, a load cell and a speed sensor; .
2. Feeding an alternating electrical current through the induction electromagnet of the second portion to consequently generate a magnetic field such that when the
generaiea magneiic Tieia links and cuts through the area of the conductive disc that rotates due to the rotation of the shaft of the rotating machine, eddy currents are generated on the disc due to the motion of the disc, the generation of the eddy currents on the disc in turn leads to the generation of a torque on the disc that opposes the rotation of the disc due to the motion of the rotating machine shaft; the induced eddy currents consequently producing another magnetic field and the interaction between the magnetic field produced by the eddy currents and the magnetic field resulting from the flow of current in the induction electromagnet causes a force to act on the induction electromagnet;
3. Measuring the force acting on the induction electromagnet due to the interaction of the magnetic fields of the disc and the induction electromagnet to provide a measure of the torque generated by the moving shaft of the rotating machine; and
4. Measuring the rotational speed of the revolving shaft of the rotating machine by way of a suitably configured speed sensor. BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a diagram illustrating a side view of a conventional absorption type eddy current dynamometer of the prior art;
Figure 2 is a diagram illustrating the exploded view of a preferable embodiment of the magnetically coupled dynamometer of the present invention;
Figure 3 is a diagram illustrating the counter-torques produced on the disk of a preferable embodiment of the magnetically coupled dynamometer of the present invention;
Figure 4 is a diagram illustrating the assembled side view of a preferable embodiment of the magnetically coupled dynamometer of the present invention; and
nyure o is a uiayram niusiraurig the front-view of a preferable embodiment of the magnetically coupled dynamometer of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The detailed description set forth below in connection with the appended drawings is intended as a description of an exemplary embodiment and is not intended to represent the only form in which the embodiment may be constructed and/or utilized. The description sets forth the functions and the sequence for constructing the exemplary embodiment. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within.the scope of this disclosure.
The magnetically coupled eddy-current dynamometer 10 of the present invention will now be described in detail with reference to figures 2 to 5.
With reference to figure 2, there is illustrated an apparatus of the magnetically coupled eddy-current dynamometer 10 of the present invention that includes a first portion 10a and a second portion 10b. The first portion 10a of the apparatus of aforementioned magnetically coupled eddy-current dynamometer 10a of the present invention includes a conductive disk 40 that is perforated in the centre to enable it to be secured fixedly by appropriate securing means to a shaft 30 of a rotating machine 20 whose torque speed characteristics are to be determined. The second portion 10b of the magnetically couple eddy current dynamometer 10 of the present invention includes a receptacle 100 (not shown) that houses an induction electromagnet 50 that comprises of a conductive coil 50a (not shown) wound around a ferromagnetic core 50b (not shown); a load cell 60; and a speed sensor 70. The second portion 10b further including a base 80 that serves to support the rotating machine 20 with its shaft 30 fitted with the conductive disc 40 of the first portion 10a and the induction electromagnet 50, the load cell 60 and speed sensor 70.
With reference to figures 3 and 4 the operation of the magnetically coupled dynamometer 10 of the present invention will be described. The rotating machine 20
conductive disc 40 of the first portion 10a is placed in close proximity to the second portion 10b.
Further to the preceding paragraph, the induction electromagnet 50, the load cell 60 and the speed sensor 70 of the second portion 10b of the eddy-current dynamometer 10 of the present invention, are housed in the receptacle 100 (not shown) such that when the induction electromagnet 50 is fed an alternating electrical current, the resulting magnetic flux lines of the magnetic field produced by the alternating current that flows through the conductive coil of the induction electromagnet 50 links and cuts through the area of the conductive disc 40 of the first portion 10a of aforementioned magnetically coupled eddy current dynamometer 10.
When the rotating machine 20 is activated, its shaft 30 and the fitted conductive disc 40 of the first portion 10a of the magnetically coupled dynamometer of the present invention rotate at a fixed velocity. The rotating of the conductive disc 40 along with the shaft 30 of the rotating machine 10 cuts the magnetic flux lines produced by the magnetic field of the induction electromagnet 50 and consequently results in the induction of eddy currents on the surface of aforementioned conductive disc 40. The induced eddy-currents on the surface of aforementioned conductive disc 40 causes the disc 40 to experience a counter-torque in the presence of the magnetic field of the induction electromagnet 50 that opposes the torque applied to rotate the disc 40 along the direction of rotation of the shaft 30 of the rotating machine 20. Additionally the eddy-currents induced on the surface of aforementioned conductive disc 40 of the magnetically coupled eddy-current dynamometer 10 of the present invention, produce another magnetic field that interacts with the magnetic field of the induction electromagnet 50 to induce a force that acts on said induction electromagnet 50.
The load cell 60 and the induction electromagnet 50 are housed within the receptacle 100 (not shown) of the second portion 10b of the magnetically coupled eddy current dynamometer 10 of the present invention such that a load cell 60 is configured to provide a measure of the force acting on aforementioned induction electromagnet 50.
By way of introduction, a load cell 60 is a transducer that is used to convert a force into a electrical signal. This conversion is indirect and happens in two stages.
merit, the force being sensed deforms a strain gauge. The strain gauge measures the deformation (strain) as an electrical signal, because the strain changes the effective electrical resistance of the wire. A load cell 60 usually includes four strain gauges in a Wheatstone bridge configuration and provides an electrical signal output is typically in the order of a few milli-volts and requires amplification by an instrumentation amplifier before it can be used.
The load cell 60 as configured in arrangement in the receptacle of the second portion 10b of the eddy-current dynamometer 10 of the present invention provides an electrical output signal which is a measure of the torque experienced by the conductive disc 40 due to the rotation of the shaft 30 of the rotating machine 20. This electrical signal is fed to a work station via a data acquisition unit, the workstation including an algorithm to compute the numerical value of the torque experienced by the conductive disc 40 due to the rotation of the rotating shaft 30 in an area of its memory.
Additionally the second portion 10b of the magnetically coupled eddy current dynamometer 10 of the present invention further includes a speed sensor 70 to provide a measure of the rotational speed of the revolving shaft 30 of the rotating machine 20.
With reference to figure 5, in a preferable embodiment of the magnetically coupled eddy-current dynamometer 10 of the present invention, the second portion 10b includes a pair of induction electromagnets 50.
In another aspect of the magnetically coupled eddy current dynamometer 10 of the present invention, there is provided a method of magnetically coupling an apparatus for the measurement of the torque and speed of a, rotating machinery 20. The method comprising the steps of:
1. Mounting a first portion 10a of aforementioned magnetically coupled dynamometer 10 that includes a conductive disc 40 on a shaft 30 of a rotating machine 20 under test and activating rotation of the rotating machine 20 under test in close proximity to a second portion 10b of the magnetically coupled
u yncii T iui i ifc!it!i i u ui Li ic present invention that includes an induction electromagnet 50, a load cell 60 and a speed sensor 70;
Feeding an alternating electrical current through the induction electromagnet 50 of the second portion 10b to consequently generate a magnetic field such that when the generated magnetic field links and cuts through the area of the conductive disc 40 that rotates due to the rotation of the shaft 30 of the rotating machine 20, eddy currents are generated on the disc 40 due to the motion of the disc 40, the generation of the eddy currents on the disc 40 in turn leads to the generation of a torque on the disc 40 that opposes the rotation of the disc 40 due to the motion of the rotating machine 20 shaft 30; the induced eddy currents consequently producing another magnetic field and the interaction between the magnetic field produced by the eddy currents and the magnetic field resulting from the flow of current in the induction electromagnet 50 causes a force to act on the induction electromagnet 50;
Measuring the force acting on the induction electromagnet 50 due to the interaction of the magnetic fields of the cylindrical conductive disc 40 and the induction electromagnet 50 to provide a measure of the torque generated by the rotating shaft 30 of the rotating machine 20; and
Measuring the rotational speed of the revolving shaft 40 of the rotating machine 20 by way of a suitably configured speed sensor 70.
Claims
1. An apparatus for a magnetically coupled eddy current dynamometer (10) that eliminates the need to physically couple and the need for accurate alignment with a shaft (30) of a rotating machine (20), characterized in that; the apparatus of the magnetically coupled eddy current dynamometer (10) comprises: a first portion (10a) that includes a conductive disc (40) fixedly mounted on a rotating shaft (30) of a rotating machine (20); and a second portion (10b) that includes: an "induction electromagnet (50) that serves to generate a magnetic field when alternating electrical current is fed through its coils; a load cell (60) configured to provide a measure of a force acting on the induction electromagnet (50) and provide a measure of a torque generated by the rotating machine (20) to rotate its shaft (30); a speed sensor (70) configured to provide a measure of the rotational speed of the rotating machine's shaft (30); and a base (80) that serves to support a rotating machine (20) fitted with the first portion (10a) and support the induction electromagnet (50), load cell (60) and the speed sensor (70).
2. An apparatus for a magnetically coupled eddy current dynamometer (10) according to claim 1 , wherein the load ceil (60) provides an electrical output signal that is proportional to the force acting on the induction electromagnet (50) and the disc (40) due to the rotation of the shaft (30) of the rotating machine (20).
3. An apparatus for a magnetically coupled eddy-current dynamometer (10) according to claim 1 , wherein the speed sensor (70) provides an electrical output signal that is proportional to the speed of rotation of the shaft (30) of the rotating machine (20).
4. An apparatus for a magnetically coupled eddy-current dynamometer (10) according to claim 2, wherein the electrical output signal of the load cell (60) is fed to a remote workstation via a data acquisition unit, the remote workstation including an algorithm to compute the numerical value of the torque acting on the conductive disc (40) due to the rotation of the shaft (30) of the rotating machine (20).
5. An apparatus for a magnetically coupled eddy-current dynamometer (10) according to claim 1; wherein the first portion (10a) and the second portion (10b) are placed in close proximity to each other, wherein the magnetic field produced by a flow of alternating electrical current in the coils of the induction electromagnet (50) of the second portion (10b) links and cuts through the area of the conductive disc (40) of the first portion (10a).
6. A method of magnetically coupling the apparatus for a magnetically coupled eddy current dynamometer (10) of claim 1 , for the measurement of the torque acting on the shaft (30) and speed of a shaft (30) of a rotating machine (20), the method comprising the steps of: i. mounting a first portion (10a) that includes a conductive disc (40) on a shaft (30) of a rotating machine (20) under test and activating rotation of the rotating machine (20) under test, in close proximity to a second portion (10b) that includes an induction electromagnet (50), a load cell (60) and a speed sensor (70); feeding an alternating electrical current through the induction electromagnet (50) of the second portion (10b) to consequently generate a magnetic field wherein the generated magnetic field links and cuts through the area of the conductive disc (40) that rotates due to the rotation of the shaft (30) of the rotating machine (20), eddy currents are generated on the disc (40) due to the motion of the disc (40), the induced eddy currents consequently producing another magnetic field and the interaction between the magnetic field produced by the eddy currents and the magnetic field resulting from the flow of current in the induction electromagnet (50) causes a force to act on the induction electromagnet (50); measuring the force acting on the induction electromagnet (50) due to the interaction of the magnetic fields of the conductive disc (40) and the induction electromagnet (50) to provide a measure of the torque generated by the moving shaft (30) of the rotating machine (20); and measuring the rotational speed of the revolving shaft (30) of the rotating machine (20) by way of a suitably configured speed sensor (70).
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| MYPI2011003998 | 2011-08-25 | ||
| MYPI2011003998 | 2011-08-25 |
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| WO2013028054A1 true WO2013028054A1 (en) | 2013-02-28 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/MY2012/000103 WO2013028054A1 (en) | 2011-08-25 | 2012-05-21 | Method and apparatus for a magnetically coupled eddy- current dynamometer |
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| WO (1) | WO2013028054A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118362231A (en) * | 2024-06-19 | 2024-07-19 | 锐马（福建）电气制造有限公司 | Coil asymmetric compensation method for electromagnetic coupling communication torque sensor |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3657923A (en) * | 1970-07-06 | 1972-04-25 | Volt Quebec Lab | Electrodynamometer |
-
2012
- 2012-05-21 WO PCT/MY2012/000103 patent/WO2013028054A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3657923A (en) * | 1970-07-06 | 1972-04-25 | Volt Quebec Lab | Electrodynamometer |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN118362231A (en) * | 2024-06-19 | 2024-07-19 | 锐马（福建）电气制造有限公司 | Coil asymmetric compensation method for electromagnetic coupling communication torque sensor |
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