JB/T 8715-1998 Acceptance specification for slewing mechanism of truck crane and tire crane
Some standard content:
JB/T 8715—1998
This standard is used in conjunction with JB/T5242-91 "Test Specification for Slewing Mechanism of Truck Cranes and Wheel Cranes". This standard is proposed and managed by Changsha Construction Machinery Research Institute of the Ministry of Construction. The responsible drafting unit of this standard: Changsha Construction Machinery Research Institute of the Ministry of Construction. The main drafters of this standard: Huang Yihong, You Xiaoping, Ding Ge. This standard is entrusted to Changsha Construction Machinery Research Institute of the Ministry of Construction for interpretation. 920
1 Scope
Machinery Industry Standard of the People's Republic of China
Acceptance Specification for Slewing Mechanism of Truck Cranes and Wheel Cranes
Regulation for approval of slewing mechanismof truck cranes and wheel cranesJB/T 8715-1998
This standard specifies the acceptance content, conditions and methods of the slewing mechanism of truck cranes and wheel cranes (hereinafter referred to as cranes). This standard is applicable to the acceptance of the quality of crane slewing mechanism products. 2 Reference 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. GB2828-87 Batch inspection counting sampling procedure and sampling table (applicable to continuous batch inspection) GB3768-83 Determination of noise source power level - simple method JB4030.1-85 Truck crane and tire crane test specification Operation reliability test JB/T5242-91 Truck crane and tire crane slewing mechanism test specification JB/T51060-94 Truck crane and tire crane product quality classification 3 Acceptance content
3.1 The slewing mechanism generally includes the following components and devices: a) power element (such as hydraulic motor, electric motor, etc.); b) reducer (including torque converter, hydraulic coupling); c) slewing pinion;
d) braking device;
e) speed regulating device;
f) operating device (only for slewing mechanisms with independent operating devices). 3.2 The acceptance of slewing mechanisms is divided into factory inspection acceptance and type inspection acceptance. 3.2.1 Factory Inspection and Acceptance
Factory inspection and acceptance is the inspection and acceptance that must be carried out on each slewing mechanism before it leaves the factory. It includes the following contents: a) Appearance inspection:
b) No-load running test;
c) Lubrication and sealing inspection;
d) Braking capacity of the brake;
e) Brakes controlled by hydraulic force also include brake opening pressure detection and acceptance. 3.2.2 Type test acceptance
Approved by the Ministry of Machinery Industry of the People's Republic of China on March 19, 1998 and implemented on July 1, 1998
JB/T8715—1998
Type test acceptance is a comprehensive inspection and acceptance of the technical performance, manufacturing quality and reliability of the slewing mechanism. In addition to the factory inspection and acceptance, the type inspection and acceptance also includes the following items: a) Determination of the weight and center of gravity of the mechanism;
b) Measurement of the overall dimensions (including installation dimensions); c) Load operation test;
d) Determination of the efficiency of the mechanism;
e) Noise measurement;
f) Braking performance test;
g) Reliability test;
h) Industrial assessment.
3.2.3 The slewing mechanism with special requirements shall be accepted according to the conditions required by the user in the contract. 4 Acceptance conditions
4.1 The slewing mechanism provided for acceptance shall comply with the provisions of 3.1, and the product standards and all required technical documents shall be submitted. 4.2 The products provided for acceptance shall complete the factory inspection or type test in accordance with the provisions of JB/T5242, and issue a test report with complete, accurate and clear test data.
5 Acceptance
5.1 Factory test acceptance
5.1.1 Before the test, it should be determined that it has been adjusted according to the design requirements to ensure that it is in normal technical condition. 5.1.2 No-load operation test and lubrication and sealing inspection 5.1.2.1 Smooth operation.
5.1.2.2 The operation of the brake, clutch, etc. is normal, without abnormal sound. 5.1.2.3 There is no looseness or abnormality in the fastening and connection parts. 5.1.2.4 During the test of the rotary mechanism, each sealing surface and pipe joint should comply with the provisions of JB/T51060. Check the oil leakage. The fixed joint surface of the sealing part should not leak, and the relative motion joint surface should not drip or the leakage area should be ≤15cm. The sealing performance is judged to be qualified, otherwise it is judged to be unqualified.
5.1.2.5 After the no-load operation, the highest relative temperature rise at each bearing seat should be lower than 50K. 5.1.3 Braking capacity test of brake
When the brake is fully braked, gradually apply 1.25 times the rated output torque to the rotating pinion three times. If the pinion does not rotate, the braking capacity is judged to be qualified, otherwise it is judged to be unqualified. The braking capacity acceptance of the worm gear rotary mechanism with self-locking function is not required. 5.1.4 Brake opening pressure value test
When the brake is fully braked, apply torque to the pinion steadily, gradually supply pressure oil to the brake oil inlet, and measure the brake opening oil pressure value when the output pinion rotates. If the brake opening oil pressure value is within 3% of the design value, it is qualified, otherwise it is unqualified.
5.2 Type test acceptance
5.2.1 Type test acceptance is the same as the factory inspection acceptance. The acceptance content shall be in accordance with the provisions in 5.1. 5.2.2 Measurement of the weight and center of gravity of the slewing mechanism The weight and center of gravity of the slewing mechanism shall comply with the technical design requirements of the product. The error shall not exceed the design value of ±3%, otherwise it shall be judged as unqualified.
5.2.3 Overall dimensions and connection and installation dimensions
The overall dimensions shall not exceed the design specified values, and the accuracy level of the connection and installation dimensions (except for special requirements) shall not be lower than IT8. 922
5.2.4 Each inspection item of the slewing pinion
JB/T 8715—1998
Perform according to the drawing requirements. If the requirements are not met, it shall be considered as an unqualified product. 5.2.5 Rated load test
5.2.5.1 During and after the rated load test, there shall be no looseness in the fastening and connection parts. 5.2.5.2 The seal of each sealing part shall be inspected and accepted according to 5.1.2.4. 5.2.6 Efficiency of slewing mechanism
5.2.6.1 Efficiency of hydraulic (hydraulic)-mechanical slewing mechanism: 7≥75%. 5.2.6.2 Efficiency of electric-mechanical slewing mechanism: 7≥90%. 5.2.7 Noise measurement
Measure the working noise of the slewing mechanism in accordance with GB3768. The limits shall meet the requirements of Table 1 respectively. Table 1 Noise limit
Power level N.
>20～30
>30～40
5.2.8 Braking performance
The acceptance of braking performance is to accept the braking capacity and braking smoothness of the brake. 5.2.8.1 Braking capacity coefficient: K.≥1.55.2.8.2 Braking torque change rate:
The measured braking torque change rate shall comply with the provisions of formula (1): M' imax/3≥aj≥M' imax/5..
Wherein: M' imux-
specified noise limit
The maximum braking torque of the brake during actual operation is generally equal to M (the resistance torque value transmitted to the shaft where the brake is located under the rated load of the slewing mechanism), kN·m; ui is the braking torque change rate, kN·m/s. 5.2.9 Reliability test
5.2.9.1 Reliability R:
a) R≥85%;
b) Reliability is calculated according to formula (2):
where: R--reliability;
ti--accumulated working time of the ith product, for the assessment test, it is the specified timing cut-off time, h: tii-the sum of the time for repairing the failure of the ith product during the test, h; n——-the number of products tested,Www.bzxZ.net
For a single rotary mechanism for assessment and acceptance, it is calculated according to formula (3): R=[to/(ta+t))X100%
where: to--accumulated working time of the product.h; {---the sum of the time for repairing the failure of the product, h. Note: tt, all do not include the specified maintenance time. 923
5.2.9.2 Mean time between failures MTBF: a) MTBF≥0.5 ta
JB/T 8715---1998
b) The mean trouble-free working time is calculated according to formula (4): MTBF=
Where: MTBF
Where: E;—
Mean trouble-free working time, h;
The number of equivalent failures that occur in the tested product within the specified reliability test time, and its value is calculated according to formula (5). rh
-The criticality coefficient of the th type of failure;
The number of th type of failures that occur in the th product.
When <1, let =1.
For a single product to be accepted, calculate according to formula (6) and formula (7): MTBF=to/r
AR: XE:
5.2.9.3 Average working time before first failure MTTFF: a) MTTFF≥0. 4 to;
b) Average working time before first failure is calculated according to formula (8): MTTFF-
Where: MTTFF-average working time before first failure, h; number of units with first failure of the tested product;
time when the first failure of the first product occurs; test cut-off time specified in reliability, calculated according to formula (9), h. t.=TN/3 600.*.
Where: T
time for each working cycle specified in JB/T5242, S;-number of cycles specified in JB/T5242 reliability test. For a single product for assessment and acceptance (i.e. n=1), this indicator is referred to as the working time before failure and is calculated according to formula (10): MTTFF
Where ·t
First failure time, h.
See Table 2 for the failure mode of the slewing mechanism.
Table 2 Failure mode of the slewing mechanism
Part name
Brake
Electric motor or hydraulic motor
Speed reducer (including hydraulic torque converter, hydraulic coupling)
Failure mode
Damage and failure
Burning or damage
Output shaft broken
Bearing damage
Casing rupture
Situation description
May cause personal injury Casualties
Cause major economic losses
Replacement of major components
Replacement of major components
Replacement of major components
Fault category and number
Part name
Pinion
Connecting bolt
General fasteners
Hydraulic system
JB/T8715—1998
Continued Table 2
Fault mode
More than one piece loose
Pipeline, pipe joint damaged
Situation description
Replace major parts
Replace parts
Must stop the machine for tightening
No need to stop the machine for tightening immediately
Cannot eliminate in time
Can eliminate in time
5.2.9.5 Q The recommended values of the criticality coefficient of the classified faults of the rotating mechanism in the reliability test are shown in Table 3 Table 3 Fault criticality coefficient
Fault category| |tt||5.2.9.6 Reliability Assessment Criteria
Fault Name
Fatal Fault
Serious Fault
General Fault
Minor Fault
Fault Category and Number
Fault Criticality Coefficient
a) Reliability acceptance shall be determined only when the average working time before the first fault (or working time before the first fault), the average trouble-free working time and reliability are all qualified. b) When a fatal fault or serious fault occurs during the reliability test, the reliability of the rotary mechanism is judged as unqualified. 5.3 After completing the reliability test acceptance, the performance retest acceptance shall be carried out according to the contents of 5.1.3, 5.1.4 and 5.2.6. 5.4 After the retest, the tested prototype shall be disassembled for inspection and acceptance, and shall meet the requirements of Table 3 in JB/T5242-91. Products that do not meet the requirements are unqualified products.
5.5 Industrial performance assessment and acceptance
The industrial performance assessment and acceptance of new products shall be carried out in accordance with JB4030.1. The contents of industrial performance assessment and acceptance shall refer to the contents of reliability test. 6 Quality inspection level
6.1 Classification of unqualified rotary mechanism
According to the definition of GB2828, the quality characteristics of the rotary mechanism do not meet the requirements, which is called unqualified. According to the severity of the non-compliance of the quality characteristics, the unqualified is divided into: Class A unqualified, Class B unqualified and Class C unqualified. a) Class A unqualified
The extremely important characteristics of the rotary mechanism do not meet the requirements, which is called Class A unqualified. b) Class B unqualified
The important characteristics of the rotary mechanism do not meet the requirements, which is called Class B unqualified. c) Class C unqualified
The general characteristics of the rotary mechanism do not meet the requirements, which is called Class C unqualified. 925
The classification of unqualified rotary mechanism is shown in Table 4.
6.2 Sampling plan
JB/T 8715 --. 1998
Table 4 Unqualified classification of slewing mechanism
Unqualified quality characteristics
Brake’s braking capacity does not meet the requirements
Brake’s braking performance does not meet the requirements
Reliability assessment does not meet the requirements
Brake oil pressure opening pressure value does not meet the requirements Mechanism efficiency value does not meet the requirements
Noise limit value does not meet the requirements
Temperature rise at bearing seat does not meet the requirements
Output pinion does not meet the requirements of the drawing
Sealing performance does not meet the requirements
General fastener tightening does not meet the requirements
Overall dimensions and connection installation dimensions do not meet the requirements Weight and center of gravity value do not meet the requirements
6.2.1 According to the provisions of GB2828, a normal sampling plan is adopted once, and the special inspection level S-1 is specified. Note
6.2.2 During batch inspection, the inspection batch N = 9 to 15 units. During product finalization and identification, the inspection batch N shall not be less than 2 units. However, when sampling from users, the sample batch size is not limited. The sample size code is A, and the sample size n is 2.6.2.3 The sample should be a qualified product with a manufacturing date of no more than three months. The sample is extracted from the submitted inspection batch. After the sample is extracted, no adjustment, repair or replacement is allowed until the end of the inspection, except for the prescribed maintenance. 6.3 Sample inspection and qualified judgment
6.3.1 According to the probability of unqualified rotary mechanism, the sample inspection qualified quality level AQL shall comply with the provisions of Table 5. Table 5 Rotary mechanism normal - sampling plan unqualified classification
6.3.2 Final evaluation of the sample
Sample size n
The sample sampling inspection is qualified, and the sample reliability is qualified, the final evaluation of the sample is qualified, otherwise it is unqualified. 7
Acceptance report
After the type test acceptance is completed, the acceptance records shall be sorted out, an acceptance report shall be written and filed for future reference, and an acceptance report and conclusion shall be issued in accordance with the provisions of this standard.
Where: T
The time of each working cycle as specified in JB/T5242, S; -The number of cycles as specified in the reliability test of JB/T5242. For a single product for assessment and acceptance (i.e. n=1), this indicator is referred to as the working time before failure, calculated according to formula (10): MTTFF
Where ·t
The first failure time, h.
The failure mode of the slewing mechanism is shown in Table 2.
Table 2 Failure modes of slewing mechanism
Part name
Brake
Electric motor or hydraulic motor
Reducer (including hydraulic converter, hydraulic coupling)
Failure mode
Damage and failure
Burning or damage
Broken output shaft
Bearing damage
Case rupture
Situation description
May cause personal injury Casualties
Cause major economic losses
Replacement of major components
Replacement of major components
Replacement of major components
Fault category and number
Part name
Pinion
Connecting bolt
General fasteners
Hydraulic system
JB/T8715—1998
Continued Table 2
Fault mode
More than one piece loose
Pipeline, pipe joint damaged
Situation description
Replace major parts
Replace parts
Must stop the machine for tightening
No need to stop the machine for tightening immediately
Cannot eliminate in time
Can eliminate in time
5.2.9.5 Q: Recommended values of criticality coefficients for classified faults of the rotating mechanism in reliability test are shown in Table 3. Table 3 Fault criticality coefficient
Fault category| |tt||5.2.9.6 Reliability Assessment Criteria
Fault Name
Fatal Fault
Serious Fault
General Fault
Minor Fault
Fault Category and Number
Fault Criticality Coefficient
a) Reliability acceptance shall be determined only when the average working time before the first fault (or working time before the first fault), the average trouble-free working time and reliability are all qualified. b) When a fatal fault or serious fault occurs during the reliability test, the reliability of the rotary mechanism is judged as unqualified. 5.3 After completing the reliability test acceptance, the performance retest acceptance shall be carried out according to the contents of 5.1.3, 5.1.4 and 5.2.6. 5.4 After the retest, the tested prototype shall be disassembled for inspection and acceptance, and shall meet the requirements of Table 3 in JB/T5242-91. Products that do not meet the requirements are unqualified products.
5.5 Industrial performance assessment and acceptance
The industrial performance assessment and acceptance of new products shall be carried out in accordance with JB4030.1. The contents of industrial performance assessment and acceptance shall refer to the contents of reliability test. 6 Quality inspection level
6.1 Classification of unqualified rotary mechanism
According to the definition of GB2828, the quality characteristics of the rotary mechanism do not meet the requirements, which is called unqualified. According to the severity of the non-compliance of the quality characteristics, the unqualified is divided into: Class A unqualified, Class B unqualified and Class C unqualified. a) Class A unqualified
The extremely important characteristics of the rotary mechanism do not meet the requirements, which is called Class A unqualified. b) Class B unqualified
The important characteristics of the rotary mechanism do not meet the requirements, which is called Class B unqualified. c) Class C unqualified
The general characteristics of the rotary mechanism do not meet the requirements, which is called Class C unqualified. 925
The classification of unqualified rotary mechanism is shown in Table 4.
6.2 Sampling plan
JB/T 8715 --. 1998
Table 4 Unqualified classification of slewing mechanism
Unqualified quality characteristics
Brake’s braking capacity does not meet the requirements
Brake’s braking performance does not meet the requirements
Reliability assessment does not meet the requirements
Brake oil pressure opening pressure value does not meet the requirements Mechanism efficiency value does not meet the requirements
Noise limit value does not meet the requirements
Temperature rise at bearing seat does not meet the requirements
Output pinion does not meet the requirements of the drawing
Sealing performance does not meet the requirements
General fastener tightening does not meet the requirements
Overall dimensions and connection installation dimensions do not meet the requirements Weight and center of gravity value do not meet the requirements
6.2.1 According to the provisions of GB2828, a normal sampling plan is adopted once, and the special inspection level S-1 is specified. Note
6.2.2 During batch inspection, the inspection batch N = 9 to 15 units. During product finalization and identification, the inspection batch N shall not be less than 2 units. However, when sampling from users, the sample batch size is not limited. The sample size code is A, and the sample size n is 2.6.2.3 The sample should be a qualified product with a manufacturing date of no more than three months. The sample is extracted from the submitted inspection batch. After the sample is extracted, no adjustment, repair or replacement is allowed until the end of the inspection, except for the prescribed maintenance. 6.3 Sample inspection and qualified judgment
6.3.1 According to the probability of unqualified rotary mechanism, the sample inspection qualified quality level AQL shall comply with the provisions of Table 5. Table 5 Rotary mechanism normal - sampling plan unqualified classification
6.3.2 Final evaluation of the sample
Sample size n
The sample sampling inspection is qualified, and the sample reliability is qualified, the final evaluation of the sample is qualified, otherwise it is unqualified. 7
Acceptance report
After the type test acceptance is completed, the acceptance records shall be sorted out, an acceptance report shall be written and filed for future reference, and an acceptance report and conclusion shall be issued in accordance with the provisions of this standard.
Where: T
The time of each working cycle as specified in JB/T5242, S; -The number of cycles as specified in the reliability test of JB/T5242. For a single product for assessment and acceptance (i.e. n=1), this indicator is referred to as the working time before failure, calculated according to formula (10): MTTFF
Where ·t
The first failure time, h.
The failure mode of the slewing mechanism is shown in Table 2.
Table 2 Failure modes of slewing mechanism
Part name
Brake
Electric motor or hydraulic motor
Reducer (including hydraulic converter, hydraulic coupling)
Failure mode
Damage and failure
Burning or damage
Broken output shaft
Bearing damage
Case rupture
Situation description
May cause personal injury Casualties
Cause major economic losses
Replacement of major components
Replacement of major components
Replacement of major components
Fault category and number
Part name
Pinion
Connecting bolt
General fasteners
Hydraulic system
JB/T8715—1998
Continued Table 2
Fault mode
More than one piece loose
Pipeline, pipe joint damaged
Situation description
Replace major parts
Replace parts
Must stop the machine for tightening
No need to stop the machine for tightening immediately
Cannot eliminate in time
Can eliminate in time
5.2.9.5 Q The recommended values of the criticality coefficient of the classified faults of the rotating mechanism in the reliability test are shown in Table 3 Table 3 Fault criticality coefficient
Fault category| |tt||5.2.9.6 Reliability Assessment Criteria
Fault Name
Fatal Fault
Serious Fault
General Fault
Minor Fault
Fault Category and Number
Fault Criticality Coefficient
a) Reliability acceptance shall be determined only when the average working time before the first fault (or working time before the first fault), the average trouble-free working time and reliability are all qualified. b) When a fatal fault or serious fault occurs during the reliability test, the reliability of the rotary mechanism is judged as unqualified. 5.3 After completing the reliability test acceptance, the performance retest acceptance shall be carried out according to the contents of 5.1.3, 5.1.4 and 5.2.6. 5.4 After the retest, the tested prototype shall be disassembled for inspection and acceptance, and shall meet the requirements of Table 3 in JB/T5242-91. Products that do not meet the requirements are unqualified products.
5.5 Industrial performance assessment and acceptance
The industrial performance assessment and acceptance of new products shall be carried out in accordance with JB4030.1. The contents of industrial performance assessment and acceptance shall refer to the contents of reliability test. 6 Quality inspection level
6.1 Classification of unqualified rotary mechanism
According to the definition of GB2828, the quality characteristics of the rotary mechanism do not meet the requirements, which is called unqualified. According to the severity of the non-compliance of the quality characteristics, the unqualified is divided into: Class A unqualified, Class B unqualified and Class C unqualified. a) Class A unqualified
The extremely important characteristics of the rotary mechanism do not meet the requirements, which is called Class A unqualified. b) Class B unqualified
The important characteristics of the rotary mechanism do not meet the requirements, which is called Class B unqualified. c) Class C unqualified
The general characteristics of the rotary mechanism do not meet the requirements, which is called Class C unqualified. 925
The classification of unqualified rotary mechanism is shown in Table 4.
6.2 Sampling plan
JB/T 8715 --. 1998
Table 4 Unqualified classification of slewing mechanism
Unqualified quality characteristics
Brake’s braking capacity does not meet the requirements
Brake’s braking performance does not meet the requirements
Reliability assessment does not meet the requirements
Brake oil pressure opening pressure value does not meet the requirements Mechanism efficiency value does not meet the requirements
Noise limit value does not meet the requirements
Temperature rise at bearing seat does not meet the requirements
Output pinion does not meet the requirements of the drawing
Sealing performance does not meet the requirements
General fastener tightening does not meet the requirements
Overall dimensions and connection installation dimensions do not meet the requirements Weight and center of gravity value do not meet the requirements
6.2.1 According to the provisions of GB2828, a normal sampling plan is adopted once, and the special inspection level S-1 is specified. Note
6.2.2 During batch inspection, the inspection batch N = 9 to 15 units. During product finalization and identification, the inspection batch N shall not be less than 2 units. However, when sampling from users, the sample batch size is not limited. The sample size code is A, and the sample size n is 2.6.2.3 The sample should be a qualified product with a manufacturing date of no more than three months. The sample is extracted from the submitted inspection batch. After the sample is extracted, no adjustment, repair or replacement is allowed until the end of the inspection, except for the prescribed maintenance. 6.3 Sample inspection and qualified judgment
6.3.1 According to the probability of unqualified rotary mechanism, the sample inspection qualified quality level AQL shall comply with the provisions of Table 5. Table 5 Rotary mechanism normal - sampling plan unqualified classification
6.3.2 Final evaluation of the sample
Sample size n
The sample sampling inspection is qualified, and the sample reliability is qualified, the final evaluation of the sample is qualified, otherwise it is unqualified. 7
Acceptance report
After the type test acceptance is completed, the acceptance records shall be sorted out, an acceptance report shall be written and filed for future reference, and an acceptance report and conclusion shall be issued in accordance with the provisions of this standard.1998
Table 4 Classification of unqualified slewing mechanism
Unqualified quality characteristics
Brake’s braking capacity does not meet the requirements
Brake’s braking performance does not meet the requirements
Reliability assessment does not meet the requirements
Brake oil pressure opening pressure value does not meet the requirements Mechanism efficiency value does not meet the requirements
Noise limit value does not meet the requirements
Temperature rise at bearing seat does not meet the requirements
Output pinion does not meet the requirements of the drawing
Sealing performance does not meet the requirements
General fastener tightening does not meet the requirements
Overall dimensions and connection installation dimensions do not meet the requirements Weight and center of gravity value do not meet the requirements
6.2.1 According to the provisions of GB2828, a normal sampling plan is adopted once, and the special inspection level S-1 is specified. Note
6.2.2 During batch inspection, the inspection batch N = 9 to 15 units. During product finalization and identification, the inspection batch N shall not be less than 2 units. However, when sampling from users, the sample batch size is not limited. The sample size code is A, and the sample size n is 2.6.2.3 The sample should be a qualified product with a manufacturing date of no more than three months. The sample is extracted from the submitted inspection batch. After the sample is extracted, no adjustment, repair or replacement is allowed until the end of the inspection, except for the prescribed maintenance. 6.3 Sample inspection and qualified judgment
6.3.1 According to the probability of unqualified rotary mechanism, the sample inspection qualified quality level AQL shall comply with the provisions of Table 5. Table 5 Rotary mechanism normal - sampling plan unqualified classification
6.3.2 Final evaluation of the sample
Sample size n
The sample sampling inspection is qualified, and the sample reliability is qualified, the final evaluation of the sample is qualified, otherwise it is unqualified. 7
Acceptance report
After the type test acceptance is completed, the acceptance records shall be sorted out, an acceptance report shall be written and filed for future reference, and an acceptance report and conclusion shall be issued in accordance with the provisions of this standard.1998
Table 4 Classification of unqualified slewing mechanism
Unqualified quality characteristics
Brake’s braking capacity does not meet the requirements
Brake’s braking performance does not meet the requirements
Reliability assessment does not meet the requirements
Brake oil pressure opening pressure value does not meet the requirements Mechanism efficiency value does not meet the requirements
Noise limit value does not meet the requirements
Temperature rise at bearing seat does not meet the requirements
Output pinion does not meet the requirements of the drawing
Sealing performance does not meet the requirements
General fastener tightening does not meet the requirements
Overall dimensions and connection installation dimensions do not meet the requirements Weight and center of gravity value do not meet the requirements
6.2.1 According to the provisions of GB2828, a normal sampling plan is adopted once, and the special inspection level S-1 is specified. Note
6.2.2 During batch inspection, the inspection batch N = 9 to 15 units. During product finalization and identification, the inspection batch N shall not be less than 2 units. However, when sampling from users, the sample batch size is not limited. The sample size code is A, and the sample size n is 2.6.2.3 The sample should be a qualified product with a manufacturing date of no more than three months. The sample is extracted from the submitted inspection batch. After the sample is extracted, no adjustment, repair or replacement is allowed until the end of the inspection, except for the prescribed maintenance. 6.3 Sample inspection and qualified judgment
6.3.1 According to the probability of unqualified rotary mechanism, the sample inspection qualified quality level AQL shall comply with the provisions of Table 5. Table 5 Rotary mechanism normal - sampling plan unqualified classification
6.3.2 Final evaluation of the sample
Sample size n
The sample sampling inspection is qualified, and the sample reliability is qualified, the final evaluation of the sample is qualified, otherwise it is unqualified. 7
Acceptance report
After the type test acceptance is completed, the acceptance records shall be sorted out, an acceptance report shall be written and filed for future reference, and an acceptance report and conclusion shall be issued in accordance with the provisions of this standard.
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