1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-8512 FAX: (724) 776-0243TO PLACE A DOCUMENT
3、 ORDER; (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS http:/www.sae.orgCopyright 1996 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.A.SURFACEVEHICLE400 Commonwealth Drive, Warrendale, PA 15096-0001INFORMATIONREPORTJ1655ISSUEDAUG96Issued 1996-08PREDICTIVE AND PREVENTIVE
4、 DIAGNOSTIC MAINTENANCE OF HYDRAULIC SYSTEMS1. ScopeThis SAE Information Report is intended to help promote the proper use of Predictive and PreventiveDiagnostic Maintenance in hydraulic systems. This document can be used as a selection guide for the level ofdiagnostic equipment and methods to speci
5、fy for a given application. Each application has its own particularrequirements.2. References2.1 Related PublicationsThe following publications are provided for information purposes only and are not arequired part of this document.2.1.1 SAE PUBLICATIONAvailable from SAE, 400 Commonwealth Drive, Warr
6、endale, PA 15096-0001.SAE J1502Pressure Test Points Installed in Mobile Equipment2.1.2 GENERAL MOTORS PUBLICATIONAvailable from General Motors Corporation, Boise Cascade, 13301Stephens Road, Warren, MI 48089.GM-1744Hydraulic Standard HS1 for Industrial Equipment2.1.3 ISO PUBLICATIONSAvailable from A
7、NSI, 11 West 42nd Street, New York, NY 10036-8002.ISO 4402Reference standards for calibration of particle counterISO 4406Classification of particles2.1.4 MILITARY PUBLICATIONAvailable from U.S. Government, DoD SSP, Building 4D, 700 Robbins Avenue,Philadephia, PA 19111-5094.Department of Defense Spec
8、ification for Hydraulic Test, Vent, and Blend Valves, Hoses and Adapters2.1.5 NFPA PUBLICATIONSAvailable from the National Fluid Power Association, 3333 North Mayfair Road,Milwaukee, WI 53222-3219.NFPA Glossary of TermsNFPA/JIC T2.24.1-1990Systems Standard for Stationary Industry Machinery, Section
9、18, DiagnosticTesting and Condition Monitoring, An industry standard for Fluid Power, Hydraulic Fluid PowerSAE J1655 Issued AUG96-2-3. Definitions3.1 Critical LocationThose locations in the circuit where pressure, flow, or direction of flow can be controlled toaffect the process.3.2 Flow Measurement
10、 DeviceA device which measures the volume or mass of fluid flowing through aconductor per unit of time.3.3 Instrument, Flow MeasuringA device which measures the flow rate of a fluid.3.4 Main Flow LineThat part of the hydraulic system from the pump or accumulator discharge to actuator andthe return l
11、ine.3.5 Turbulent FlowA flow situation in which the fluid particles move in a random fluctuating manner.3.6 Laminar FlowA flow situation in which the fluid moves in parallel lamina or layers.3.7 Shear Stress“The force, per unit area, with the direction defined, related to flow.”13.8 ViscosityA measu
12、re of internal friction or the resistance of a fluid to flow.3.9 Regular BasisFrequency of fluid sampling that relates to the hydraulic system contamination generationand ingestion rates.3.10 Trend AnalysisThe use of baseline signature and subsequent signatures to predict future performance ofthe sy
13、stem and scheduled maintenance.3.11 Fluid AnalysisA chemical analysis of the system hydraulic fluid and its particulate contamination.3.12 System InspectionAn inspection of components, circuitry, and system variables as listed in Section 4 asthey relate to system performance, consistent with the pre
14、ventive maintenance plan.3.13 Performance HistoryA compilation of all signatures, maintenance records, and preventive maintenancedata.3.14 System FlushingThe process of cleaning to remove the initial residual contamination from the inside ofconductors and components of the assembled system to achiev
15、e a defined level of cleanliness.3.15 Vibration AnalysisThe measurement and recording of vibration parameters to determine trend.21. Fluid Mechanics, Victor L. Streeter, McGraw-Hill, 1958.2. Vibrations, William W. Seto, B.S. in M.E., M.S.SAE J1655 Issued AUG96-3-4. Hydraulic System CategoriesHydraul
16、ic systems must be categorized into levels of relative complexity anddegrees of criticalness to the process. Complexity shall be rated by the system operating pressure, type ofcomponents and their relationships to the overall hydraulic system. There are six levels of complexity.4.1 Complexitya. Pres
17、sure less than 1000 psiSolenoid valves.b. Pressure less than 2000 psiSolenoid valves.c. Pressure less than 2000 psiProportional valves.d. Pressure greater than 2000 psiProportional valves.e. Pressure less than 2000 psiServo valves.f. Pressure greater than 2000 psiServo valves.Hydraulic systems shall
18、 also be categorized into degrees of criticalness. There are four degrees ofcriticalness.4.2 Criticalnessa. Zero ImpactOff-line support equipment with no impact on the process.b. Minor ImpactSystem can be shut down, as required, with minimal impact on the process.c. Major ImpactSystem can be shut do
19、wn only at scheduled intervals as dictated by the process.d. Shutdown ImpactSystem must run continuously to support the process.4.3 CategoryBased on the level of complexity and the degree of criticalness, each combination falls into one offour categories as shown in Table 1. Once the hydraulic syste
20、m is categorized, it is necessary to evaluatesystem variables and the diagnostic requirements.5. System Variables to ConsiderSee Section 3.a. Pressure (static, differential, transient)b. Flow Ratec. Temperatured. Rotation Speede. Horsepowerf. Vibrationg. Electrical Currenth. Fluid Contaminationi. Fl
21、uid Typej. Fluid Viscosityk. Fluid Levell. Environmental Considerationsm. Any other variable that may impact the reliability of the fluid power systemSAE J1655 Issued AUG96-4-TABLE 1HYDRAULIC SYSTEM DIAGNOSTIC CHARTCriticalnessImpact on theProcessComplexityLevel 1Pressure(2000 psi)Proportional Valve
22、sComplexityLevel 5Pressure(2000 psi)Servo ValvesZero ImpactOff-line, support equipment1 2 2 2 2 3Minor ImpactSystem can be shut down as required, with minimal impact on the operation of the system1 2 2 2 3 4Major ImpactSystem can be shut down at scheduled intervals only.2 2 3 3 4 4ShutdownSystem ope
23、ration is vital to the process. System must run continuously.3 3 3 4 4 4Diagnostic Category 1a. Plugged, threaded, test ports located at all pressure adjustment locations.b. Provisions for installing a flowmeter or flow-sensing device in the main supply line.c. Visual temperature indication (thermom
24、eter) at the reservoir.d. Visual reservoir fluid level indication.Diagnostic Category 2Includes all the requirements of Category 1.a. Connect-under-pressure test ports and connectors or permanent pressure-sensing devices at all pressure adjusting locations.b. Provisions for installing a flowmeter or
25、 flow-sensing device in the main supply line. Other critical lines as necessary.c. Permanent temperature measuring at the reservoir. Visual thermometer or temperature switch as specified by user.d. Amperage measurement on the prime mover (electric motor).e. A test port and permanently installed valv
26、e for fluid sampling.Diagnostic Category 3Includes all the requirements of Category 1 and 2.a. Permanent pressure-sensing devices at all pressure adjusting locations.b. Permanent flowmeter installed in main supply line. Additional provisions for flowmeter installations at other critical areas.c. Per
27、manent temperature measuring capability at the reservoir (temperature switch).d. Amperage measurement of the prime mover (electric motor).e. Initial vibration signatures and provisions for scheduled vibration measurements.f. A test port and permanently installed valve for fluid sampling.g. Two level
28、, automatic, reservoir fluid level monitoring.Diagnostic Category 4Includes all the requirements of Category 1, 2, and 3.a. Previously mentioned transducers shall have the ability to communicate measured parameters over RS232C or RS485 or in an analog format. This information can be available either
29、 directly from each transducer or through a processor.b. Fluid contamination level shall be monitored on a regular basis. This monitoring shall consider both particulate contamination and water content.c. Consideration shall also be made for monitoring fluid chemistry and the chemistry of the contam
30、inants.SAE J1655 Issued AUG96-5-6. Minimum Diagnostic Requirements for Each CategoryWith complexity and criticalness defined andvariables listed, the minimum required diagnostic hardware shall be:6.1 Category 1 Systemsa. A connect-under-pressure test port located at the main pressure controlb. Provi
31、sions for installation of a flowmeter in the main flow linec. Provisions for temperature measurement of the fluid in the reservoird. Visual reservoir fluid level indicator6.2 Category 2 SystemsIncludes all the requirements of Category 1 and the following:a. Connect-under-pressure test ports or perma
32、nent pressure-sensing devices at all locations wherepressure can be adjusted.b. Provisions for easy installation of a flowmeter in the main flow linec. Permanently installed fluid temperature measurement device in the reservoird. Provisions for current measurement amperage) of the electric prime mov
33、er.e. A test port for fluid sampling in a line with turbulent flow.6.3 Category 3 SystemsIncludes all the requirements of Categories 1, 2, and the following:a. Permanent pressure-sensing devices with peak hold provisions within “smart sensors” or within thedisplay instrument, at all locations where
34、pressure can be adjusted. Additional connect-under-pressure test ports at all other critical locations.b. Flow measurement device, permanently installed, in the designated main flow line. Additionalprovisions for easy installation of a flow measurement device at all other critical locations.c. Provi
35、sions for easy installation of a flow measurement device at all pump outlets.d. Permanently installed temperature measurement devices in all the following locations:1. In the fluid in the reservoir2. In the main pump outlet3. In the designated main flow linee. Provisions for rotation speed and curre
36、nt measurement of the electrical prime mover.f. Permanent connect-under-pressure test port for fluid sampling in a line with turbulent flowg. Provide low and critical low fluid level monitoring electricallyh. Provision for vibration measurement (per user requirements)6.4 Category 4 SystemsIncludes a
37、ll the requirements of Categories 1, 2, 3, and the following:a. Previously mentioned transducers shall have the ability to communicate measured parameters overRS232C, RS485 serial interfaces or in an analog format. This information can be available directlyfrom each transducer or through a processor
38、.b. Fluid contamination level shall be monitored on a regular basis. This monitoring shall consider bothparticulate contamination and water content.c. A definitive plan shall be implemented for monitoring on a regular basis, both chemistry of the fluid andthe chemistry of the contaminants.SAE J1655
39、Issued AUG96-6-7. Preventive and Predictive Diagnostic Maintenance ProgramIn addition to listing minimum diagnosticequipment requirements on various systems, this document recommends procedures for implementing apredictive and preventive maintenance program:a. Include all original equipment manufact
40、urers manuals in an operating manual for the overall system.This manual shall include all electrical and fluid systems schematics, as well as componentinformation.b. All original equipment manufacturers guidelines, recommendations, and procedures shall be followed.c. Conduct a performance test of th
41、e overall system at the suppliers facility and at future tests. Thesetests will be used as signatures for a comparison to future tests. The system performance, at optimumlevel, will be used as the system signature. Identify tolerances around specific parameters whereverpossible. The data, accumulate
42、d under this point, is the baseline of a good predictive and preventivemaintenance program.d. The manufacturers guidelines for routine maintenance, shall be followed. Repeat the tests describedpreviously, on a scheduled basis. Note any changes from the original tests and compare to theallowable tole
43、rances. Investigate any items that are not within tolerances.e. Maintain precise records of all measurements and use for trend analysis.f. Establish a preventive maintenance plan (based on the systems needs) for routine system services,such as:1. Filter element replacement2. Fluid analysis3. Vibrati
44、on analysis4. Components and system inspectiong. Use the system performance history, as defined previously, to develop a predictive maintenanceprogram for major system service items such as:1. Pump rebuilds and replacements2. Valve replacements3. Seal kit replacements4. Hose/conductor replacementsh.
45、 Use the system performance history to avoid unnecessary shutdowns and provide data for futurereliability computations.8. Diagnostic RecommendationsThe following suggestions are listed for collecting diagnostic data:a. Size all sensing devices to fit the system operating ranges.b. When installing fl
46、owmeters, use 10 diameters length of the inside diameter of the fluid conductorupstream and 5 diameters length of the inside diameter of the fluid conductor downstream of the flow-measuring devices to improve accuracy.c. Allow the system to attain proper operating temperature prior to making adjustm
47、ents.d. Include diagnostic ports in all manifolds to measure pressure at Pressure, Return, Drain Pilot, andActuator Ports. These ports shall be permanently identified.e. Startup procedures shall include “system flushing” in addition to other manufacturers startupprocedures.f. Manufacturers recommend
48、ations shall be followed for selection and use of diagnostic equipment.PREPARED BY THE SAE SYSTEMS DIAGNOSTICS COMMITTEESAE J1655 Issued AUG96RationaleNot applicable.Relationship of SAE Standard to ISO StandardNot applicable.ApplicationThis SAE Information Report is intended to help promote the prop
49、er use of Predictive andPreventive Diagnostic Maintenance in hydraulic systems. This document can be used as a selectionguide for the level of diagnostic equipment and methods to specify for a given application. Eachapplication has its own particular requirements.Reference SectionSAE J1502Pressure Test Points Installed in Mobile EquipmentGM-1744Hydraulic Standard HS1 for Industrial EquipmentISO 4402Reference standards for calibration of particle counterISO 4406Classification of particlesDepartment of Defense Specification for Hyd
