JB/T 50103-1998 This standard can be used as an expansion of GB/T 14405-93 "General Bridge Crane" to increase the reliability requirements of general bridge cranes. This standard specifies the reliability assessment indicators, fault classification and judgment criteria, test methods and assessment results of general bridge cranes. This standard is applicable to mass-produced bridge cranes. Other bridge cranes can also refer to it. JB/T 50103-1998 General Bridge Crane Reliability Assessment Specification JB/T50103-1998 Standard download decompression password: www.bzxz.net

JB/T 50103--1998
This standard specifies the reliability index for general-purpose bridge cranes and determines the specific content and methods of reliability assessment test. This standard can be used as an expansion of GB/T14405-93 "General-purpose bridge cranes" to increase the reliability requirements for general-purpose bridge cranes.
This standard is only used by crane manufacturers to conduct reliability assessment tests on batch products and cannot be used as an acceptance standard for a particular crane.
Appendix A and Appendix B of this standard are both appendices to the standard. This standard was proposed and managed by the Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. The responsible drafting unit of this standard: Beijing Hoisting and Conveying Machinery Research Institute of the Ministry of Machinery Industry. The main drafter of this standard: Xu Lei.
This standard is published for the first time.
1 Scope
Machinery Industry Standard of the People's Republic of China
General-purpose bridge crane
Reliability Assessment Test Specification
(Internal Use)
JB/T 50103---1998
This standard specifies the reliability assessment indicators, fault classification and judgment criteria, test methods and assessment results of general-purpose bridge cranes.
This standard is applicable to mass-produced general-purpose bridge cranes. Other bridge cranes can also be used as a reference. 2 Referenced Standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T3187--94 Terms of reliability and maintainability GB5080.1-86 General requirements for equipment reliability test GB/T14405-93 General bridge crane
JB/T7518--94 Guidelines for reliability assessment of electromechanical products 3 Reliability assessment indicators
3.1 Mean first trouble-free working time
The average value of the cumulative working time when the crane has the first fault MTTFF
Where: n-the number of cranes put into the test; the number of cranes with the first fault; t-the cumulative working time of each mechanism when the first prototype has the first fault; - the cumulative working time of each mechanism of the first prototype that has not failed at the end of the reliability test. Note: When the test result r=0, MTTFF: 3.2 Equivalent mean trouble-free working time
The average working time between two adjacent faults of the crane. MTBF-
In the formula: N
The total number of various types of failures that occur in the crane within the test deadline, which needs to be weighted according to the provisions of 4.3.4; tei-the cumulative working time of each mechanism of the i-th prototype. Approved by the Ministry of Machinery Industry of the People's Republic of China on March 19, 1998 380
Implemented on July 1, 1998
Note: When the test result N=0, MTBF=3
3.3 Average repair time
The average repair time of crane failure. JB/T50103-—1998
In the formula: N-the total number of various types of failures that occur in the crane within the test deadline, which does not need to be weighted tr
The repair time required for the i-th failure, including fault diagnosis, repair and debugging time. 3.4 Availability (A.)
The proportion of time that the crane can maintain its specified function. Working time
A. Working time + Song working time
Where: -The time that the i-th crane cannot work, including fault repair time, preventive maintenance time, guarantee time and management time. 4 Fault classification and judgment
4.1 Fault definition
Crane failure refers to all phenomena that the whole machine, components or parts cannot complete their specified functions and the performance drops to outside the specified range. 4.1.1 Associated failure
When the crane is used under specified conditions, the failure caused by its inherent defects is an associated failure. This type of failure includes: failure caused by the crane performance parameters failing to meet the specified values ​​of the technical requirements; failure of the crane metal structure affecting the load-bearing capacity; failure of the components on the motion chain of each mechanism of the crane affecting normal operation; failure of the crane electrical equipment causing the crane to stop, etc. 4.1.2 Non-associated failure
Crane failures caused by misuse, improper maintenance or external factors are non-associated failures. This type of failure includes: failures caused by improper crane operation; failures caused by inherent defects in supporting equipment that should be eliminated during regular crane maintenance; failures caused by the crane's wearing parts reaching the specified life; failures caused by violations of various regulations on crane transportation, installation, commissioning, operation, maintenance, etc. that are not the responsibility of the manufacturer.
4.1.3 Subordinate failures
Derivative failures caused by a certain failure. 4.2 Fault classification
According to the degree of harm caused by the failure of the crane, the severity of the damage and the difficulty of repair, the failures are divided into four categories: fatal failures, serious failures, general failures and minor failures. 4.2.1 Fatal failures
Endanger or cause personal injury, serious damage to equipment and major economic losses or other intolerable consequences. 4.2.2 Serious failures
The main parts or the entire crane are seriously damaged, the function is lost, the repair cost is high, the impact is large or it cannot be repaired in a short time, and the main parts need to be replaced or dismantled to eliminate them. 4.2.3 General fault
General parts of the crane are damaged, resulting in the inability to complete some functions, with medium repair costs and general impact, which can be eliminated in the short term. 4.2.4 Minor fault
It only has a slight impact on the crane's completion of the specified functions, and can temporarily keep the whole machine in normal operation. The repair cost is low and the maintenance is simple. The fault can be adjusted or eliminated during the downtime maintenance period. 381
4.3 Fault judgment criteria
JB/T50103-—1998
4.3.1 When calculating the number of crane faults, only the number and category of related faults are counted. If the fault mode is the same and occurs multiple times, each time it is a related fault, it should be counted. If a subordinate fault is caused by a related fault, its number of faults will not be counted, and only the primary fault that caused the subordinate fault will be counted, but the fault classification should be determined according to the fault with the most serious consequences it caused. 4.3.2 Non-related faults are not counted in the number of human faults. According to the product manual, if the wearing parts that need to be replaced regularly fail due to failure after the expiration date, no fault treatment will be performed, but records should be made and explained in the test report. 4.3.3 Fault classification can be determined according to Appendix A (Appendix to the standard). Due to the variety of crane types and various failure modes, if a failure mode not listed in Appendix A is found, its category can be determined according to the fault classification principle and the examples in Appendix A. 4.3.4 Fatal faults, serious faults, general faults and minor faults are weighted and counted respectively. Taking general faults as the benchmark, the fault count is 1, the fatal fault count is 20, the serious fault count is 4, and the minor fault count is 0.5. The number of faults after weighted counting is the equivalent number of faults. 5 Sampling method
5.1 Test prototype
The test prototype should be a product that is mass-produced after finalization and meet the requirements of GB/T14405. The test prototype should also be a product that is mass-produced under the same production conditions and has a similar service history. The prototype should be consistent with the working level in actual use, with a high full load rate and a more frequent use rate. The applicable environment, operating conditions and operation and maintenance of the prototype should meet the requirements specified in the product manual or order contract. 5.2 Sampling base
In order to ensure the confidence level of the reliability test results, the sampling base should be as large as possible, generally not less than 1/3 of the annual production, and at least 10 units.
5.3 Sampling method
A random sampling method is adopted, and the test prototype can be selected according to 1/10 of the sampling base, but at least 3 prototypes are put into the test. 5.4 Prototype documents
Each prototype should be accompanied by a factory certificate, factory inspection report, installation and operation manual, random spare parts list, acceptance inspection report, prototype sampling registration form, etc.
6 Test method
6.1 Preparation before test
6.1.1 The reliability test is carried out by using the method of on-site data feedback analysis. It is necessary to install a timer on the circuit of the lifting mechanism, trolley running mechanism and carriage running mechanism of each prototype to record the operating hours of the mechanism. 6.1.2 After the installation and commissioning of the bridge crane is completed, the test prototype shall be subjected to no-load test, static load test and dynamic load test in accordance with the provisions of the instruction manual, and records shall be kept. The test can only be put into operation after the formal delivery. 6.2 Test process
6.2.1 Appoint a dedicated person to observe and record the cumulative working hours displayed on the timer of each mechanism every day. When the test prototype fails or stops for maintenance, the date of failure, failure mode, cause of failure, hours of each timer, maintenance method, parking hours, repair hours, etc. should be recorded in time. Associated failures, non-associated failures, and subordinate failures must be recorded in detail in the failure record form as the original data for reliability assessment. The test record form is shown in Appendix B (Standard Appendix).
6.2.2 During the test, the maintenance and inspection of the prototype should be carried out strictly in accordance with the technical maintenance cycle and content specified in the instruction manual, and the maintenance items, content, time used, personnel, etc. should be recorded in detail. During the assessment process, if there are maintenance, maintenance, adjustments, replacement of parts, etc. outside the specified items, they are generally treated as associated failure counts. 6.2.3 During the test, if the prototype fails, it should be eliminated in time and it is not allowed to work in a faulty state. Analyze the cause of the failure, and attach a simple diagram or photo if necessary. Before the cause of the damage is determined, the damaged parts replaced shall be kept by the test responsible unit for future reference. 6.2.4 The test adopts the timed truncation method. The total cumulative running hours of each mechanism of each test prototype shall not be less than 1500h, and the reading of the timer shall prevail.
JB/T50103-1998
6.2.5 After the test, the test prototype shall be fully inspected and disassembled for inspection if necessary to find out all the faults that have not been recorded. The occurrence time of these faults shall be calculated according to the test truncation time. 6.2.6 In the reliability assessment test, if the prototype is seriously damaged due to non-related faults and cannot be tested further, the spare prototype can be activated or the sample can be re-tested.
7 Reliability assessment
7.1 Assessment method
7.1.1 After the test, the true value of each reliability index of the batch of test prototypes shall be calculated according to the assessment index and calculation method in Chapter 3 and the fault judgment criteria in 4.3. When calculating, the cumulative working time of the crane is the sum of the cumulative working time of the hoisting mechanism, trolley running mechanism and trolley running mechanism. wwW.bzxz.Net
7.1.2 During the test, if any prototype has a fatal failure, the test should be stopped immediately and the whole batch of products should be judged as unqualified.
The calculated values ​​of each reliability index must comply with the specified values ​​of the reliability index in Table 1. 7. 1.3 Name
Table 1 Specified values ​​of reliability index
Indicator name
Mean first time to work without failure MTTFF
Equivalent mean time to work without failure MTBF
Mean time to repair MTTR
Service availability A.
7.2 Test summary
≥250h
≥320h
After the test, in addition to preparing the reliability assessment test report, it is also necessary to prepare the failure analysis report and the reliability assurance measures report. 7.2.1 The fault analysis report is filled in by the test unit, and the content mainly focuses on the serious faults and fatal faults that have occurred during the test, including related faults and non-related faults, as well as the time of discovery of these faults, fault phenomena, fault causes, measures taken, maintenance methods, maintenance time, fault judgment criteria and measures to be taken to prevent such faults from happening again. 7.2.2 The reliability assurance measures report shall be filled in by the manufacturer of the tested crane, and product improvement measures shall be proposed based on the test results. The content shall include analysis of weak links affecting product reliability, reliability assurance measures in the design stage, reliability assurance and control measures in the manufacturing stage and key processes, reliability assurance measures for outsourced and purchased parts, reliability assurance measures for packaging, transportation and installation, usage information feedback and after-sales service measures, etc.
Basic parameters
Metal structure
Lifting mechanism
Trolley running mechanism
JB/T 50103--1998
Appendix A
(Appendix to the standard)
Failure modes and classification table of general bridge cranes Table A1 Failure modes and classification table of general bridge cranes Failure mode
Lifting capacity does not meet the requirements of the order contract
Lifting or running speed is unstable and does not meet the requirements of the order contractLifting height is less than the requirements of the order contract
Crane noise exceeds the standard
Cracks occur in the web or cover of the main beam
Main welds of the main beam are dewelded or crackedThe waviness of the web of the main beam exceeds the standard
Permanent deflection of the main beam
Side bending deformation of the main beam exceeds the standard
Deformation of the end beam
Open welding or web tearing of the end beam
Broken high-strength bolts at the connection between the main and end beamsCracks in the weld at the connection between the main and end beams
Trolley Track loosening
Main force-bearing welds of the trolley frame are open
The height difference between the two main beams exceeds the standard
Dynamic stiffness of the main beam exceeds the standard
The straightness of the trolley track exceeds the standard
Local deformation of the structure
The deformation of the trolley frame is large, resulting in excessive vibration of the three-point running platform
The platform and railings are open
Speed ​​regulation failure
Empty hook cannot descend
Lifting weight limiter failure
Descending braking distance exceeds the standard
Height limiter failure
Lifting trolley derailment
Trolley runs crookedly and chews the rail
Travel limit failure
Situation description
Affecting normal use
Affecting productivity
Affecting normal use
Affecting normal use
Affects normal use
Affects normal use,
Affects normal use
Affects normal use
No serious consequences
Can be repaired during maintenance
No back nest
Adjustable
No consequences
Adjustable
No consequences
Causes should be analyzed
No consequences
Obstacle classification
Trolley operating mechanism,
Trolley operating mechanism
Electromagnetic suction cup
Pulley block
Braking distance exceeds the standard
Collision safety ruler is damaged
Crane derailment
JB/T50103—1998
Table A1 (continued)
Failure mode
Insufficient capacity of windproof and anti-skid device
Failure of windproof and anti-skid device
Crooked operation of bridge frame and gnawing of rails
Damage of track sweeping plate
Exceeding braking distance
Failure of travel limit
Broken hook handle
Cracks on hook surface
Exceeding opening of hook
Cracks on hook crossbeam
Cracks on hook side plate||t t||The hook cannot rotate freely
The action is out of adjustment and cannot grab the material
The wire rope is out of the groove
The grab bucket structure is cracked
The blade plate or teeth of the bucket are very easy to wear
The hinge shaft is broken
The cable drum of the electric grab bucket is damaged
The suction force is seriously insufficient for a long time
The cable drum is damaged
The cable is broken
The residual magnetism is too large
Pulley broken
Welded pulley weld cracked
Spindle broken
Pulley cannot turn
Pulley tilted, loosened
Axial movement of pulley
Wire rope jumps
Uneven wear of pulley groove
Situation description
No consequences
Causes to be analyzed
Serious consequences
Affecting use
No consequences
No consequences
No consequences
Need to be replaced
Need to be replaced
Normal operation
Not in line with life guarantee
Material meets requirements
Affecting operation
Need to be replaced
Adjustable
No serious consequences
Failure Fault classification
Wire rope
Winding system
Coupling
Broken wire exceeds the standard
JB/T50103—1998
Table A1 (continued)
Failure mode
Kink, bending, severe deformation
Strand or wire extrusion
: Local increase or decrease in rope diameter
Excessive wear||t t||Excessive corrosion
Cracks in the wire rope balance arm
Damage to the wire rope wedge joint
Loose wire rope clamp
Interference of wire rope
Failure of wire rope balance device
Cracks in the coupling half
Excessive wear or breakage of the gear of the toothed coupling Cutting of the connecting bolts
Wear of the connecting bolts and pin shaft holes
Keyway Pressure stains and deformation
Wear of pins, column pins, rubber rings, etc.
Installation concentricity exceeds the standard
Situation description
Consequences caused by quality problems
Affecting normal use
Fault classification
Brake
JB/T50103-—1998
Table A1 (continued)
Fault mode
The lever system is stuck
Insufficient braking torque
Broken brake arm or pull rod, damaged main spring, broken pin The push rod does not retract in time after power failure or the moving iron core does not release The brake pad rivets are all cut off or the clamping pad baffle falls off The brake wheel is broken
There is oil stain on the brake wheel and brake pad
Excessive wear of the brake pad
Plastic deformation of the spring||t t||Brake lever locking nut loosened
Brake pad and brake shoe slide relative to each other
Retraction equalization device fails
Wheel pin nut loosened
Tie rod screw thread disengaged
Brake pad retraction is too large
Hinge point of lever system is stuck
Failure of control and power supply line
The pusher fails and cannot be pushed out
The pusher has insufficient thrust or insufficient stroke
The electromagnet coil is burned
The elastic tension is too large
The long-stroke brake hammer is over-tightened
The pusher leaks oil seriously
The brake wheel is cracked or easily worn
The pin hole is excessively worn
The brake wheel rubs against the rivet
Situation description
Causes the brake to be ineffective
No
serious consequences
causing the brake to be unable to be effectively opened, no
consequences
need to stop the machine for repair
Fault classification
Lifting mechanism
Operating mechanism
Reducer
Buffer
Gear tooth breakage
Tooth surface bonding
Reducer shaft breakage
Reducer bearing damage
JB/T50103199 8
Table A1 (continued)
Failure mode
Decelerator high-speed output shaft keyway damage
Tooth surface pitting
Periodic gear chatter
Tooth surface plastic deformation
Severe metal friction sound, housing vibration
Gear meshing has uneven hook knocking sound
Decelerator heats up as a whole, especially the bearing installation place heats up. The reducer vibrates on the base
Tread and spokes have cracks
Bearing damage|| tt||Wheel rim deformation and breakage
Wheel tread peeling
Excessive wheel wear
Uneven wear of driving wheel tread
Cracks on drum
Damage to drum
Loosening of wire rope fixing bolts
Damage to drum shaft and key
Damage to drum coupling
Wear of drum rope groove and rope jumping
Uneven arrangement of wire rope
Axial movement of drum
Bearing damage| |tt||Insufficient buffer capacity
Cracks in springs, rubber, and polyurethane
Oil leakage from hydraulic buffer
Loosening of connection device
Permanent deformation of buffer body
Damage to impact head
Situation description
Repairable during maintenance
Replaceable during maintenance
No consequences
Adjustable
No consequences
Affecting use
Fault classification||t t||Driver's cab
Motor
Contactor
Relay
JB/T50103—1998
Table A1 (continued)
Failure mode
"Cracks appear at the connection with the bridge
Poor design, seriously affecting the operating field of vision
Window glass is not firmly fixed
Excessive vibration
Water leakage on the top, poor sealing
Damage to the air conditioner or heater
Lighting damage
Motor burns out
Rated speed cannot be reached at rated load
Abnormal sound during operation
Sparks on brush bones or burnt slip rings
Slip rings open circuit
Loose connection
Winding overheats
Vibration and loud noise during operation
Coil burns out
Slow pull-in and release actions
Contacts overheat or burn out
Discharge occurs between phases of positive and negative contactors
Contact piece falls off
Poor contact contact, contact welding
Mechanical failure, malfunction
Serious noise from electromagnet
Overheating of coil
Serious electrical wear of contact
Abnormal action
Inaccurate adjustment, difficult to adjust
Poor control sensitivity
Parts breakage, failure
Contact stuck or out of contact
Contact failure
Situation description
Design reasons
No consequences
Adjustable
No consequences
Replaceable during maintenance
Impact on use
Adjustable
No consequences
Adjustable
Replaceable during maintenance
No consequences
Fault classification
Limit switch
Resistor
Power supply device
Control device
JB/T 50103-1998
Table A1 (end)
Failure mode
No protection after action
Poor contact of contacts
Misoperation
Burning or crashing
Loose wiring, poor contact
Separation of slip ring and sliding wire
Poor contact, phase failure or phase insulation breakdown, sliding wire short circuit to ground
Trolley cable is scraped off
Power supply failure
Cable outer skin is seriously cracked
Cable pulley is not flexible
Controller card Stuck, unable to operate
Controller operation failure
Controlled motor does not work
Fuse burns out
Controlled motor can rotate in one direction
Generator is not excited
After the power is cut off, the contactor of the protection box does not drop the valve control line circuit break
Situation description
No consequences
No consequences
No consequences
Due to quality reasons
No consequences
To analyze the reasons
No consequences
Fault classification
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