WO2015002617A1

WO2015002617A1 - Multi-function machine condition analyzer instrument

Info

Publication number: WO2015002617A1
Application number: PCT/TH2014/000003
Authority: WO
Inventors: Jirapong Lim
Original assignee: Jirapong Lim
Priority date: 2013-07-01
Filing date: 2014-02-07
Publication date: 2015-01-08

Abstract

Multi-function machine condition analyzer instrument for industrial condition base maintenance (CBM) which can be switched to various types of useful instruments to aid machine maintenance job more effectively. The main function of this instrument is for machine bearing checker and analyzer by using the Acoustic Emission(AE) and Vibration(VB) signal hybrid system that capable for measuring and analyzing high speed and very slow speed machinery, down to 0.1RPM. The hybrid information of both signals are combined and analysis by the AE-VB hybrid module software that evaluates machine condition and indicate of possible machine symptom and root cause in each particular cases to the operator.

Description

MULTI-FUNCTION MACHINE CONDITION ANALYZER INSTRUMENT

BACKGROUND OF INVENTION

Machine condition inspection for most industries is relatively important for their production process. It would reduce machine maintenance cost and reduce machine problems and breakdown during in production that cause of large amount of production value lost. The major problem of machine breakdown is bearing parts degradation and damage. Several techniques for checking machine condition are as follows:

1) Acoustic Emission (AE) Technique is the used to detect high frequency that generated by bearing material worn-out during machine operation. This technique is very efficient for early stage of bearing abnormal detection, such as lack of lubrication and contamination. Therefore, the bearing life time can be extended by solving those problems. However, the AE technique could not estimate defect size and deterioration of bearing condition.

2) Vibration Analysis technique is the most popular and widely used in industries for machine condition monitoring purposed. Because it can be used to analyze root causes of the bearing problems such as unbalance and misalignment. However, the vibration technique is relatively difficult to do analysis and would not detect early stage defect and slow speed bearing,

3) Temperature Measurement is also useful for general proposed machine condition evaluation. It can be used to check bearing condition but the result is not very accurate due to ambient temperature may change and effect its results. The temperature check can also indicate the final stage of bearing condition.

Those techniques provide different advantages and disadvantages; thus, several techniques must be used for the most efficient condition based maintenance(CBM) result. However, various types of instrument have to be invested and required many operators for taking data from all machines. The data will be stored in data based software which are different type and brand of instruments. This may causes difficulty for data evaluation and analysis.

Therefore, this invention relates to the instrument for monitoring, detecting, storing and analyzing signals that are collected from machine condition. This instrument has been designed for multifunction measurement techniques which provide multiple data for machine condition evaluation in the same data base. Moreover, the data will be analyzed automatically by rule based software that is not required much operator experience to evaluate machine condition. The test results can be more accurate than general CBM instruments for industry.

DETAILS AND DESCRIPTIONS

The machine condition analyzer instrument in this invention comprises of the Main Processing Unit (MPU), Touch Screen Display for receiving command as user interface and Multiple Sensors Interface(MSI). The MSI connectors are prepared for Acoustic Emission (AE) transducer, Vibration transducer, Temperature sensor and other measurement sensors that must be related to application software installed in the MPU. This instrument is designed for measuring and analyzing high speed and very low speed machinery, down to 0.1 RPM. A digital camera and sound recorder are installed for additional information of machinery condition data based management. The MPU is prepared for wireless communication and devices, such as Bluetooth wireless headphone for hearing abnormal bearing noise demodulated from Acoustic Emission or Vibration signal. The measurement results and data can be transferred to data base software in personal computer(PC) via Wi-Fi or 3G network.

The aim of this invention is the new concept of industrial CBM analyzer instrument which can be switched to various types of useful instruments to aid machine maintenance job more effectively. Multi-function of this instrument can be added by installing new applications software via PC wirelessly and the appropriate transduce must be installed.

However, the main function of this instrument is for machine bearing check and analysis by using the Acoustic Emission and Vibration signal hybrid system. The hybrid information of both signals are combined and analysis by the AE-VB hybrid module software that evaluates machine condition and indicate of possible machine symptom and root cause in each particular cases to the operator.

Furthermore, this instrument has been prepared for direct interface with other transducers and devices that are related to software module for particular applications, including; Temperature Scanner, Thermal Image Camera, Air or vacuum leak detection and Ultrasonic thickness Measurement, and etc. BRIEF DESCRIPTION OF THE DRAWINGS

The features of the invention believed to be novel and the elements characteristic of the invention are set forth with particularity in the appended claims. The figures are for illustration purposes only and are not drawn to scale. The invention itself, however, both as to organization and method of operation, may best be understood by reference to the detailed description which follows taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a block diagram of the Multi-function Machine Condition Analyzer Instrument in accordance with one embodiment of the present invention.

FIG. 2 shows the use of AE and Vibration Sensors hybrid measurement for the present invention.

FIG. 3 shows a main screen allowing operator to select different measurement type in accordance with the present invention.

FIG. 4 shows a screen of AE-Bearing Checker software with indicated bearing condition for the present invention. FIG. 5 shows an AE-Spectrum Analyzer screen display with the bearing problem indicator for the present invention.

FIG. 6 shows an AE-VB Hybrid Analyzer screen with bearing symptom and machine problem indicator for the present invention.

DISCLOSURE OF THE INVENTION

The present invention is a multifunction instrument for condition base maintenance analyzer which comprises of components, as shown in block diagram, Fig.1. In the diagram, battery (13) is a power supply to operate the main processing unit, MPU(l) which is utilized for measurement data processing and analysis as depending on the application software. The MPU(l) is connected to a Solid Stage Data Storage(4) via Serial ATA Bus at speed of 1.5Gb/s and the software is operated and displayed on the Liquid Cristal Display(LCD) screen(2)via Video Graphic Adapter Interface from the MPU. The operator can select a the appropriate measurement function for machine condition testing by the resistive type touch panel(3) which is installed on the LCD screen. The touch panel is connected to the MPU via Universal Serial Bus Interface at speed of 12Mbit/s. The operator command is transferred to the MPU to retrieve the selected application program and data from the data storage(4). Then the instrument is ready to operate in the selected application. The power supply voltage from battery( 13) is increased by a DC to DC Step-Up Voltage converter circuit(9) to the suitable voltage level for each sensor and transducer. The voltage is also stabilized by the Voltage regulator power supply circuit(7) and then the regulated voltage is supply to Acoustic Emission sensor(14). The Acoustic Emission sensor( 14) has a resonance frequency of 100kHz. Sine-Wave analog signal output from the sensor is transmitted to the Enveloper Signal conditioning circuit(6) to improve signal characteristic. Then it is fed to the amplifier circuit(5) to increase signal level to be suitable for the multiplexer circuit(l l), which has scanning rate of 50,000 Sample/Sec. The analog signal from multiplexer is converted to 14bits digital data by analog to digital converter(lO). Those components, 10 and 1 1, are known as Data Acquisition Unit that communicates to the MPU( l ) via Universal Serial Bus Interface at bit rate of 30Mb/s. The data are processed with the specified application software in the MPU(l) to analyze and evaluate the measurement results. The machine condition information are displayed on the LCD screen, including; Acoustic Emission time domain waveform, frequency domain graph, and AE-Crest Factor with a bearing condition conclusion. The invention utilizes an AE signal dynamic envelope derived for the value of AE-Crest Factor referred to as AE-Cf.

The AE-Cf. is proportional to the expression Z=((X_max ^~S)/M)^Y Where:

Z- AE-Crest Factor,

sampled value, and

S= Mean of minimum samples value

=RMS value of sampled waveform.

7=Bearing calibration ratio Typical variations in this variable ratio experienced in practice range from 1 to 10 for normal bearing condition. The AE signal is also converted to audio signal to allow operator hear a bearing abnormal noise via the Bluetooth wireless headphone.

A machine vibration is measured by the Vibration sensor( 15), which is powered by the constant Current Regulator power supply(8). The vibration signal, lOOmV/g, from the sensor is fed to the Band Pass Filter( 12) then the output is connected to the Amplifier(5). The amplified signal is converted to digital format by the Multiplexer circuit 1 1 and the Analog to Digital converter(10), respectively. The digital signal is transmitted to the MPU(l) which analyzes the signal to the major vibration parameters and evaluate the machine condition. The Acoustic Emission(AE)and vibration(VB) sensors are employed and both signals are analyzed together when hybrid function software is selected, as shown in FIG.2. The Hybrid measurement provides advantages for condition base maintenance including; lubrication problem warning, early stage bearing fault detection, and accurate root cause analysis. The AE and VB time waveform with FFT spectrum plot are presented on the LCD screen. The machine condition warning and fault evaluation are also indicated to the operator by using Bearing Failure Index, (BFI)

The BFI parameter is proportional to the expression BFI^ VBRM^AERM ) ^)^7' Where:

Vibration signal Root Means Square,

AERMS = Acoustic Emission signal Root Means Square,

Y= Bearing calibration ratio

Z=AE-Crest Factor

The temperature sensor(16) or other type sensors that providing analog voltage output can be interfaced to the MPU(l) via the Multiplexed 1 1), same as the AE sensor connection. Moreover, additional devices, including; wireless communication module, Bluetooth module, and CCD camera module are also connected to the MPU(l) via the Universal Asynchronous Receiver/Transmitter(UART) interface. They are used for recoding sound and photos with other additional data in order to use for further analysis. The headphone(19) with Bluetooth interface allows the operator hearing the abnormal bearing noise. Description of the instrument screen

1 ) Main screen is the first menu after startup the instrument, as shown in FIG3. The installed applications software are shown in the menu that ready to use.

2) AE-Bearing Checker screen is used for bearing condition evaluation which is analyzed by Acoustic Emission technique during the machine operation. The parameter, AE-Crest Factor, in FIG.4 can be used to indicate machine condition and evaluate level of bearing defect with no requirement of bearing details and previous trend data based. The AE signal wave form with AE-Crest Factor are very useful for bearing condition evaluation which are messages on the LCD screen including; 1 ) Normal condition, 2)Suspect condition, and 3) Poor condition. The AE-Crest factor range between 0-100, has meaning as follows: 0-5=[very good condition], 6- 10=[normal condition], 1 l-20=[Lubrication problem], 21-30=[small defect], and over 31=[defect].

3) AE-Spectrum Analyzer screen is very useful for root cause analysis, as in FIG.5. The FFT-AE frequency domain is presented and it can be calculated for bearing defect frequency. Rule base evaluation is employed to investigate machine symptom and indicate problems message for the operator.

4) AE-VB Hybrid Analyzer screen is the module that employs both techniques between Acoustic Emission and Vibration for bearing diagnostic. The Signal waveform and Spectrum plot of both signal are presented on the screen to compare and evaluate problem. The machine diagnostic is analyzed and displayed in form of horizontal bar chart which is compare between five cases, of the machine problems, including; l)Normal condition, 2)Lubrication Problem, 3)Unbalance, 4)Missed Alignment, 5)Looseness. The bearing symptom is categorized into four cases that includes l)Inner race defect, 2)Outer race defect ,3)Cage defect, and 4)Ball defect. Those indications are used to compared for the most possible problem of the machine and bearing, as shown in FIG.6.

The Machine Condition Analyzer Instrument in this invention can be changed to several applications that involve to condition base maintenance, including; Bearing checker and Analyzer, Vibration analyzer, Temperature scanner, Thermal image camera, Ultrasonic thickness measurement, and shaft alignment instrument. The novel technique using Acoustic Emission and Vibration signal merging, so called AE-VB Hybrid, is applied in this invention to provide higher accurate machine condition results and simple to use than conventional technique.

While the present invention has been particularly described, in conjunction with a specific preferred embodiment, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. It is therefore contemplated that the appended claims will embrace any such alternatives, modifications and variations as falling within the true scope and spirit of the present invention.

Claims

Thus, having described the invention, What is claimed is:

1) The multifunction instrument for condition base maintenance analyzer has specific designed which comprises of battery (13) is a power supply for the main processing unit, MPU(l). It is utilized for measurement data processing and analysis as depending on the application software. The MPU(l) is connected to a Solid Stage Data Storage(4) and the software is operated and displayed on the Liquid Cristal Display(LCD) screen(2). An appropriate measurement function can be selected for machine condition testing by the touch screen panel(3) which is connected to the MPU. The operator command is transferred to the MPU to retrieve the selected application program and data from the data storage(4). Then the battery voltage is stepped-Up by the voltage converter circuit(9) and stabilized by the voltage regulator circuit(7) and then supply to Acoustic Emission sensor(14).

The Acoustic Emission sensor(14) has a resonance frequency of 96kHz. The sensor signal output is converted to the Dynamics envelope format by Enveloper Signal conditioning circuit(6). Then it is fed to the amplifier circuit(5) to increase signal level to be suitable for the multiplexer circuit(l l). The signal output from multiplexer is converted to digital format by the analog to digital converter(lO) and the transmitted to the MPU( 1 ) to analyze the AE-Crest Factor for machinery and bearing condition evaluation.

The Vibration sensor(15) for machine vibration measurement, requires the constant Current Regulator power supply(8) to be operated. The vibration signal, lOOmV/g, is fed to the Band Pass Filter(12), Amplifier(5), and Multiplexer circuit(l 1) respectively. Then the signal is transferred the MPU(l) via the Analog to Digital converter( lO) and to be calculated for basic vibration parameters to evaluate the machine condition.

2) The Multi-function Machine Condition Analyzer Instrument according to Claim 1, has additional sensors and devices, including; temperature sensor, ultrasonic transducer, digital microscope camera, thermal image camera

3) The Multi-function Machine Condition Analyzer Instrument according to Claim 1, employs the wireless communication module(18) for wireless data transfer. The digital camera(17) is also installed to the MPU(l ) for taking photos of measuring point that is used for data base management.

4) The Multi-function Machine Condition Analyzer Instrument according to Claim 1, presents the Acoustic Emission and Vibration signal time waveform and frequency domain.

5) The Multi-function Machine Condition Analyzer Instrument according to Claim 1, converts Acoustic Emission signal to audible frequency that allow operator hear abnormal bearing noise via the Bluetooth wireless headphone(19).

6) The Multi-function Machine Condition Analyzer Instrument according to Claim 1, provides specific AE signal analyzing technique for the parameter of AE-Crest Factor, which is calculated from statistical value between maximum and minimum of AE dynamic envelope signal. This factor is simple to use and very effective to evaluate the bearing condition without requirement of bearing specifications and measurement data base history.

7) The Multi-function Machine Condition Analyzer Instrument according to Claim 6, the AE-Crest Factor with the time waveform is used for bearing condition that is indicated on the instrument screen in three cases, including 1) Normal Condition, 2) Suspect

Condition, 3)Poor Condition. The AE-Crest factor range between 0-100, has meaning as follows: 0-5=[very good condition], 6-10=[normal condition], 1 l-20=[Lubrication problem], 21-30=[small defect], and over 31=[defect]. 8) The Multi-function Machine Condition Analyzer Instrument according to Claim 6, employs specific data processing AE-VB Hybrid technique. The machine condition warning and fault evaluation are indicated by using Bearing Failure Index, (BFI) which is displayed on the instrument screen in five cases, including 1) Normal Condition, 2) Lubrication Problem, 3)Unbalance, 4)Missed Alignment , 5) Looseness. The bearing defect is also categorized into four cases that are: 1) Inner race defect, 2) Outer race defect, 3) Cage defect, 4) Ball defect and it also displayed on the instrument screen to justify for operator.