MT/T 681-1997 English PDFUS$349.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email. MT/T 681-1997: Reducer for belt conveyor for coal mining. Technical condition
Basic dataStandard ID: MT/T 681-1997 (MT/T681-1997)Description (Translated English): Reducer for belt conveyor for coal mining. Technical condition Sector / Industry: Coal Industry Standard (Recommended) Classification of Chinese Standard: D93;J81 Classification of International Standard: 53.040.20 Word Count Estimation: 10,195 Date of Issue: 12/30/1997 Date of Implementation: 6/1/1998 Summary: This standard specifies the coal belt conveyor reducer technical requirements and test content, requirements and methods. This standard applies to coal belt conveyor reducer. MT/T 6:---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.Reducer for belt conveyor for coal mining.Technical condition People's Republic of China Coal Industry Standard Technical conditions of reducer for belt conveyor in coal mine 1997-12-30 Approved.1998-06-01 Implementation Approved by the Ministry of Coal Industry of the People's Republic of China Contents1 Scope 1 2 Normative references 1 3 Technical requirements 1 4 Test method 4 5 Inspection rules 6 6 Marking, packaging, transportation, storage 7ForewordThis standard mainly references ZBJ19009-88 "General technical conditions for cylindrical gear reducers" and MT 101-90 "for scraper conveyors Reducer Inspection Specifications. This standard is proposed by the Department of Science, Technology and Education of the Ministry of Coal Industry. This standard is under the jurisdiction of the Standardization Technical Committee for Special Equipment for Coal Mine of the Ministry of Coal Industry. This standard was drafted. Coal Research Institute Shanghai Branch. The main drafters of this standard. Liu Chenyang, Chen Yu, Li Feng, Wang Yungen, Zhang Bochao. This standard entrusts the Shanghai Branch of the China Coal Research Institute to interpret. Technical conditions of reducer for belt conveyor in coal mine1 ScopeThis standard specifies the technical requirements and inspection contents, requirements, and methods of belt conveyor reducers for coal mines. This standard applies to reducers for belt conveyors used in coal mines.2 Reference standardsThe following standards contain provisions that, through reference in this standard, constitute provisions of this standard. When this standard was published, the editions shown were all Is effective. All standards will be revised, and all parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T 3077-88 Technical conditions for alloy structural steel GB/T 3323-87 Radiography and quality classification of steel fusion welded butt joints GB/T 3768-83 Simple method for determination of sound power level of noise sources GB/T 9439-88 gray cast iron GB/T 10095-88 involute cylindrical gear accuracy GB/T 11365-89 Accuracy of bevel gears and hypoid gears GB/* 11368-89 Cleanliness of gear transmission MT/T 101-93 Inspection Specification for Reducer for Scraper Conveyor ZBJ19004-88 cylindrical gear reducer ZBJ19005-88 Cylindrical gear reducer loading test method ZBJ19009-88 general technical requirements of cylindrical gear reducer ZBJ19026-90 reducer for transportation machinery Coal Mine Safety Regulations (92 edition)3 Technical requirements3.1 Conditions of use 3.1.1 The reducer shall meet the requirements of this standard and be manufactured in accordance with the drawings and documents approved by the prescribed procedures. 3.1.2 The working environment temperature of the reducer is -10 ~ 40 ℃; when the ambient temperature is lower than 0 ℃, the lubricating oil should be preheated accordingly. 3.1.3 The working conditions of the reducer shall comply with the provisions of the "Coal Mine Safety Regulations". 3.2 Service life The service life of the reducer must not be less than.20000h, and the service life of the bearing must not be less than 5000h. 3.3 Sealing performance The reducer must be free from oil leakage or oil leakage, and dirt and water must not be allowed to penetrate into the body. 3.4 Mechanical efficiency Under rated load, the oil temperature of the reducer reaches the thermal equilibrium temperature, or the oil temperature of the reducer using internal water cooling is 75 ℃ ± 5 ℃ When the reducer is a hard toothed surface transmission, the efficiency of each stage is not less than 0.98; soft toothed surface transmission. the efficiency of each stage is not less than 0.965. 3.5 Body and cover 3.5.1 The box can be cast or welded. When casting, its mechanical properties must not be lower than HT200 in GB/T 9439. 3.5.2 The casting body and cover must not have casting defects such as slag inclusion, shrinkage, looseness, cracks, etc. 3.5.3 Weldments of weldments shall meet the requirements of Class I welds in GB/T 3323. 3.5.4 The casting body and cover need to be aged, and the welding body and cover need to be annealed. 3.5.5 The kerosene leakage test should be performed before the box assembly, and the box must not have oil leakage or oil leakage. 3.5.6 When the bonding surface of the machine body and the cover is in a free bonding state, the contact tightness of the bonding surface should be checked. Stuffed. 3.5.7 After the body and the cover are closed, the edges should be flush, and the displacement of each side should not be greater than 2mm. 3.6 Gears and gear shafts 3.6.1 The main transmission parts shall be forgings, and the materials used shall comply with the requirements of GB/T 3077, and all shall have the manufacturer's certificate or the right Inspection Qualification Form for the operation. 3.6.2 When the power of the reducer is less than 90kW, the accuracy of the three tolerance groups of the gear must not be lower than the level 8 specified in GB/T 10095 When the power is greater than or equal to 90kW, the accuracy of the third tolerance group of the gear must not be lower than level 7, and the accuracy of the first and second tolerance groups must not be lower than level 8. 3.6.3 Cylindrical gear inspection items shall comply with the requirements of Table 1, and other equivalent inspection item combinations are allowed. Table 1 Tolerance group Ⅰ Tolerance group Ⅱ Tolerance group Ⅲ Fr and Fw ff and fpt Fβ 1 When one of them is out of tolerance, the gear accuracy should be checked and accepted according to Fp. 2 Each inspection accuracy value is selected in accordance with GB/T 10095. 3.6.4 The contact spots on the tooth surface of the spur gear shall meet the requirements in Table 2. Table 2 Contact spots,% Accuracy class Press height is not less than 65 65 65 65 55 (45) 50 (40) 45 (35) 40 (30) Not less than 95 95 95 90 80 70 60 50 1 The values in parentheses are used for helical gears with axial coincidence ε 0.8. 2 The accuracy of each inspection shall be selected in accordance with GB/T 10095. 3.6.5 The minimum normal backlash of a spur gear shall meet the requirements in Table 3. table 3 Center distance/mm Minimum normal limit backlash/μm Center distance/mm Minimum normal limit backlash/μm ≤80 120 315 ~ 400 230 80 ~ 125 140 400 ~ 500 250 125 ~ 180 160 500 ~ 630 280 180 ~ 250 185 630 ~ 800 320 250 ~ 315 210 800 ~ 1000 360 3.6.6 The inspection items of the bevel gear shall comply with the requirements in Table 4, and other equivalent inspection item combinations are allowed. Table 4 Tolerance group Ⅰ Tolerance group Ⅱ Tolerance group Ⅲ Gear gear pair gear gear pair gear gear pair Fp and Fpk Fic Fpt and Fck Fskc Contact spots 3.6.7 The minimum normal limit backlash of the bevel gear is selected from class b specified in GB/T 11365, the maximum normal limit backlash and the minimum normal limit. The value of backlash should meet the requirements of GB/T 11365. 3.6.8 The contact spots of bevel gears and hypoid gears should meet the requirements of Table 5. table 5 Contact spots,% Accuracy class 4 ~ 5 6 ~ 7 8 ~ 9 Not less than 60 50 35 along the tooth length Not less than 65 55 50 along the tooth height direction 3.6.9 Tooth surface roughness Ra≤6.3μ. 3.6.10 After the gearbox has been rated for 1000 hours of durability under rated load, the gear teeth shall meet the requirements of Table 6. Table 6 Remarks on identification criteria of serial number items1 WearThe gear is allowed to show slight or moderate wear.The amount of wear must not exceed the following requirements. 1. Hard tooth surface tooth wear of any tooth surface should not be greater than 0.13mm. 2. The amount of wear on any tooth surface of the soft tooth surface gear must not be greater than 1/20 of the tooth thickness. 3. The tooth surface of the gear with uneven wear, the difference between the two ends of the tooth surface should not be greater than 0.08mm. 2 Slight cementing is allowed on the glued tooth surface, and the glued area must not be greater than 1/4 of the tooth height; 1/3 of the tooth width3 PittingEarly tooth pitting is allowed on the tooth surface of the gear teeth, but the size of the pits and the area of the pitting pits must not exceed the following Provisions. 1.For gears with a modulus of less than 6, the average diameter of pits must not be greater than 1mm; for teeth with a modulus of more than 6 The average diameter of wheels and pits shall not be greater than 2mm. 2.Pitting pit area is invalid when it reaches the following conditions. a. When the width of the pitting area accounts for 80% of the tooth height; b. The width of the pitting area accounts for 70% of the tooth height, and the length of the pitting area accounts for 10% of the tooth length; c. The width of the pitting area accounts for 30% of the tooth height, and the length of the pitting area accounts for 40% of the tooth length Average diameter = (maximum straight Diameter min diameter) ÷ 24 No peeling of tooth surface of peeling wheel5 Plastic deformation1. Hard tooth surface gear teeth must not be plastically deformed. 2. The amount of plastic deformation of the soft tooth surface gear teeth must not be greater than 1/20 of the tooth thickness6 Broken teeth must not break7 No cracks in any part of the gear8 Interference damage No interference damage to the tooth surface3.7 Determination of bearing failure After the 1000h durability assessment of the reducer under the rated load, the bearing should meet the requirements of Table 7. Table 7 Remarks on identification criteria of serial number items1 Wear1. The bearing is allowed to wear lightly, and its wear coefficient f≤7.5. 2. There must be no obvious change in the shape of the raceway. 3. The raceway surface does not allow a dim appearance f = v/e0 v. Clearance increment e0. with bearing ID-related values2 PittingThe inner and outer rings, rolling elements and cages of the bearing allow early pitting, but the size of pits and pitting pits The area must not exceed the following requirements. 1. The average diameter of pits shall not be greater than 1mm, and the depth shall not be greater than 0.1mm. 2. The area of pitting pits must not be greater than 20% of the surface area of the part itself Average diameter = (most Large diameter minimum straight Diameter) ÷ 23 All parts of the bearing must not be peeled off4 All parts of the cracked bearing must not be cracked. Never allow the inner and outer rings of the bearing and the cage to break5 glued bearings must not be glued6 Plastic deformation of each part of the bearing must not occur plastic deformation3.8 Lubrication and cooling of the reducer 3.8.1 Lubrication method and type of lubricating oil of the reducer, see Appendix A of ZBJ19009. 3.8.2 The oil temperature of the oil tank of the reducer shall not exceed 100 ℃, and the temperature rise of the oil temperature shall not exceed 80 ℃. 3.9 Assembly technical requirements 3.9.1 All parts and components shall be inspected in accordance with the requirements of their technical documents, and they may be assembled and used only after they are qualified. 3.9.2 Check the minimum backlash of the gear pair, contact spots and the axial clearance of each shaft component according to the standard or drawing requirements. 3.9.3 The reducer should run smoothly without impact. 3.9.4 After the reducer is assembled, no residues are allowed in the box, and the cleanliness shall meet the Class J requirements specified in GB/T 11368. 3.9.5 The operating noise value of the reducer below 160kW must not be greater than 90dB (A) (comprehensive noise), above 160kW (including 160kW) The operating noise value of the reducer must not be greater than 92dB (A) (comprehensive noise). 3.9.6 The non-machined surface of the body, the inner wall of the cover and the parts located inside the reducer body shall be coated with oil and acid resistant paint. Body, machine The surface of the cover and other exposed non-machined parts can be painted according to the relevant standards, and can also be painted according to user requirements.4 Test method4.1 Test prototype The test prototype is a qualified product or prototype to be shipped. 4.2 Test bench Test driving and loading methods and other devices are not limited. Priority is given to closed power streaming with lower energy consumption. The main requirements for the inspection platform. --- The load torque and speed are stable, and the fluctuation should not exceed ± 5%; --- Can be loaded and unloaded during operation; --- The installation of the tested reducer on the inspection device should conform to its working condition and tightening method. 4.3 Conditions to be met by all test instruments 4.3.1 The accuracy requirements of measuring instruments, meters and measuring tools are as follows. --- Power. The accuracy of direct reading measurement is ± 0.5%, and the accuracy when measuring by sensor is ± 1.0%; --- Torque. measurement accuracy is not less than ± 1%; --- Rotation speed. measurement accuracy is not less than ± 0.5%; --- Temperature. measurement accuracy is not less than ± 1% ± 1 last digit; --- Noise. measurement accuracy is ± 1dB (A); --- Measuring tool. Select the accuracy according to the tolerance range required by the test product drawing. 4.3.2 The measuring instruments, meters and measuring tools must be calibrated and calibrated according to relevant national standards and regulations, and have a validity Inspection certificate. 4.3.3 Instruments should be placed in a constant temperature room during the test to ensure the stability of the test instruments. 4.4 Test items, procedures and requirements See Table 8. Table 8 Test item test content and method requirements 1 No-load test a) The reducer runs continuously under no load until the oil temperature is balanced at the rated speed until; b) record room temperature; c) After the motor starts to the rated speed, record the oil every 15 minutes Temperature, the temperature rise of oil temperature within 1h does not exceed 1 ℃ balance; d) Start to measure and record the input torque, rotation Speed; output torque, speed; no-load power, housing temperature at the bearing, Speed oil temperature 1) The rotation direction of the reducer must be the same as the working direction the same; 2) running smoothly without impact and noise; 3) No oil leakage or oil leakage at each seal and joint2 Efficiency testa) After passing the no-load test, perform the efficiency test; b) Increase by 10% of the rated load value until 100%, and load step by step Test, each gear runs for 30min; c) Record the speed and torque of each gear. In three groups, take the arithmetic mean; d) When the shaft output torque is 100% of the rated value, continue to run until the heat level After the balance, the speed and torque are recorded from 10 minutes after the thermal equilibrium; e) After the test, replace the new oil to the design oil level 1) Under rated load, the mechanical efficiency should meet the requirements of 3.4 Regulations; 2) Draw load-efficiency curve3 Temperature rise testa) Under rated load and rated speed, the reducer runs continuously until the oil The temperature of the cell reaches thermal equilibrium; b) Record the temperature of the oil sump every 15min, while monitoring and recording the shaft Bearing temperature; c) recording the ambient temperature; d) Record the time required to reach thermal equilibrium 1) The maximum oil temperature of the reducer oil pool and the temperature rise of the oil pool should be Meet the requirements of 3.8.2; 2) Continuous operation at rated load, oil temperature reached The time required at 100 ℃ shall not be less than 3h; 3) When the reducer uses a forced cooling system, its cooling But the parameters must meet the design requirements4 Noise testa) noise test at the same time as the rated load-efficiency test; b) Measure the side and record the front, top and side of the reducer under test 1m Noise at the place; c) The side to be measured refers to the side away from the motor 1) Take the maximum noise value; 2) The maximum noise value of the reducer should meet the requirements of 3.9.5. Regulations5 overload testa) At the rated speed, gradually and gradually load the 120%, run for 10min b) Record input, output speed, torque and power 1) Normal operation, no abnormal noise or abnormal system System vibration; 2) Open the cover for inspection, do not allow broken teeth, tooth surface pulling, Phenomena such as indentation, gluing, pitting, etc. Table 8 (continued) Test content and method requirements6 Endurance testa) 1000h continuous operation at rated load and speed; b) The oil temperature should be controlled below 80 ° C; c) record the oil temperature every 1h; d) Measure and record the plane, high-speed shaft and Three-point vibration of vertical, axial and horizontal points at low speed shaft bearings (For operation reference); e) During the test, two oil changes are allowed; f) Perform shutdown inspection at 500h and make detailed records. If the tooth surface is good Or the tooth surface has local pitting, and the pitting is non-expanding pitting. Keep experimenting 1) normal operation; 2) If there is abnormal vibration or noise during operation, etc. It should be dismantled immediately; 3) When the shutdown inspection is performed at 500h, observe the gear meter Surface. contact spots should meet the requirements of Table 2 and Table 5; The pitting and cementation of the tooth surface should meet the requirements of 3.6.10 Provisions; 4) After the test, complete disassembly and inspection, and check the gears and bearings And other major parts for comprehensive quality inspection. Gears each The inspection indicators shall meet the requirements of 3.6.10. axis The various indicators should be consistent with the provisions of 3.7; 5) Do not replace any parts during the test5 Inspection rules5.1 Inspection classification There are two types of inspections for reducers for belt conveyors. type inspection and factory inspection. The inspection items are shown in Table 9. Table 9 Inspection Item Inspection type Type inspection and factory inspection 1 No-load test √ √ 2 Efficiency test √- 3 Temperature rise test √ √ 4 Noise test √ √ 5 Overload test √- 6 Endurance test √- Note. "√" means inspection, "-" means no inspection. 5.2 Type inspection 5.2.1 Type inspection shall be carried out in one of the following cases. --- When the national quality supervision agency proposes a type inspection requirement; --- When the trial production of new or old products is transferred to the factory for trial production identification; --- After the production is officially put into operation, if there are major changes in structure, technology and materials, which may affect product performance; --- When the product is suspended for a long time, when it resumes production again; --- Reducers produced in batches are sampled every 3 years; --- When users have objections to product quality, when they ask for it. 5.2.2 Number of spot ch......Tips & Frequently Asked Questions:Question 1: How long will the true-PDF of MT/T 681-1997_English be delivered?Answer: Upon your order, we will start to translate MT/T 681-1997_English as soon as possible, and keep you informed of the progress. 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