JB/T 5945-1991 General technical requirements for construction machinery assembly
Some standard content:
Machinery Industry Standard of the People's Republic of China
JB/T 5945-1991
Engineering Machinery
General Technical Conditions for Assembly
1991-12-12 Issued
Implementation by the Ministry of Machinery and Electronics Industry of the People's Republic of China on 1992-07-01
Mechanical Industry Standard of the People's Republic of China
Engineering Machinery
General Technical Conditions for Assembly
1 Subject Content and Scope of Application
JB/T 5945 - 1991
This standard specifies the technical requirements, test methods, inspection rules and marking, packaging, transportation and storage of engineering machinery products. This standard applies to the assembly of engineering machinery products. 2 Reference standards
JB/T5936
JB/T5943
GB10095
GB11365
JB/T5948
ZBJ85017
JB/T5949
ZBJ85018
JB/T5946
3 Technical requirements
3.1 General requirements
General technical conditions for machined parts
Construction machinery
Construction machinery
General technical conditions for welded parts
Precision of involute cylindrical gears
Precision of bevel gears and bevel hypoid gears
Technical conditions for caliper disc brakes for construction machinery
Steering brake bands for crawler bulldozers
Technical conditions for shoe brakes for construction machinery
Double universal joints for crawler bulldozers
General technical conditions for painting of construction machinery
3.1.1 All parts to be assembled must have inspection qualification marks; purchased parts and cooperative parts must have documents proving their qualification before they can be assembled.
All painted parts shall not be assembled before the paint is completely dry. 3.1.2
3.1.3 Before assembling parts, iron filings, burrs, oil stains, mud and sand and other debris must be cleaned up; rust, scratches and bumps are not allowed on the mating surfaces and friction surfaces. The mating surface should be cleaned and coated with an appropriate amount of lubricating oil (grease) after drying. The oil holes and oil grooves of the parts should be clean and unobstructed. 3.1.4 The connection between the box body, reading body and other parts must be tight. After assembly, it is not allowed to process holes that communicate with the inner cavity. 3.1.5 Mechanical processing such as drilling and tapping during the assembly process should comply with the provisions of JB/T5936; welding should comply with the provisions of JB/T5943.
3.1.6 After the parts are assembled, an appropriate amount of lubricating oil (grease) must be injected into each lubrication point. 3.2 Assembly of fasteners
3.2.1 During the assembly process, the threaded part of the bolts and screws must not be damaged. 3.2.2 The end faces of the bolt and screw heads and nuts should be in uniform contact with the plane of the fastened parts, should not be tilted, and it is not allowed to use a hammer to make the two planes contact.
3.2.3 It is strictly forbidden to use inappropriate wrenches when tightening screws and nuts. They must be tightened symmetrically and in turns. When the tightening torque requirement is not specified, the tightening torque can refer to Table AI in Appendix A (reference part). Approved by the Ministry of Machinery and Electronics Industry on December 12, 1991 and implemented on July 1, 1992
JB/T5945-1991
3.2.4 After the nut is tightened, the tongue of various stop washers should be bent immediately. The anti-loosening safety wire on the bolt head should be installed and wrapped tightly according to the thread rotation direction. When using double nuts and no adhesive to prevent loosening, the thick nut should be installed first. 3.2.5 When assembling a tapered pin with a diameter greater than 4mm with a hole, its contact rate shall not be less than 50%. After the tapered pin with a screw tail is installed, the large end must be sunk into the relevant part 2 to 3 buckles.
3.3 Assembly of rolling bearings
3.3.1 When the bearing is hot-assembled by the temperature difference method, the bearing should be heated to 90 to 100℃ before assembly. However, bearings with dust covers or seals cannot be assembled using the temperature difference method.
3.3.2 When the bearing is assembled using the press-in method, it should be pressed in by a press machine, and the pressure should not be transmitted through the rolling element. If it is necessary to hit with a hammer, a copper rod or other object that does not damage the surface of the assembly should be placed in the middle, and the striking force should be evenly distributed on the seat ring with interference fit. 3.3.3 When installing the bearing, the marked wax surface should face outward. 3.3.4 The outer ring of the bearing should fit well with the semicircular holes of the bearing seat and the bearing cover. It can be checked by coloring or by measuring the gap with a feeler gauge. When checking with coloring, it should be evenly in contact with the bearing seat within a range of 120° symmetrical to the center line, and evenly in contact with the bearing cover within a range of 90° symmetrical to the center line. When checking with a 0.03mm feeler gauge within the above range, it is not allowed to insert 1/3 of the width of the outer ring of the bearing. 3.3.5 For bearings using grease, clean grease equivalent to 65%~80% of the cavity volume should be injected into the bearing cavity after assembly. 3.3.6
For bearings lubricated with thin oil, grease shall not be added. After the inner ring of the bearing is assembled, it must be close to the shaft shoulder or the distance ring, and there must be no insertion when checking with a 0.05mm feeler gauge. After cleaning, the removable bearing must be assembled according to the original assembly position, and it is not allowed to be mixed or reversed. After the tapered roller bearing is installed, the axial clearance shall comply with the provisions of Table 1. Table 1
Bearing inner diameter
>10~30
>30~50
>50~80
β=10°~16
0. 04 ~ 0. 07
0. 05~-0.10
6. 08~0.15
Note: β is the contact angle between the ball and the outer ring of the bearing. Value
Bearing inner diameter
>80~120
>120~180
>180~260
P=10°~16°
0,12~0.20
0.20~0.30
0.25~0.35
3.3.10 After the bearing is assembled, it should be able to rotate evenly and flexibly. Under normal working conditions, the bearing temperature rise shall not exceed 50℃, and the maximum temperature shall not exceed 80℃.
3.4 Assembly of sliding bearings
3.4.1 The oil grooves on the bushing and bearing shell must be smooth and clean. 3.4.2 When the bushing is installed into the bearing seat, it should be pressed in by a press and must not be skewed. When hammering with a hand hammer, a soft metal pad and a guide mandrel or guide ring must be placed in the middle. The striking force should be evenly distributed on the circumference. The contact angle between the bearing and the journal should comply with the provisions of Table 2. 3.4.3
Table 2 Contact angle between the bearing and the journal
Shaft speed
Contact angle
≤500
70°~-100°
3.4.4 The contact spots between the bearing and the journal should comply with the provisions of Table 3. Table 3 Contact spots between the bearing and the journal
Shaft speed
Contact spots on an area of 25mm×25mm (pcs) $100
>100~500
3.4.5 Under normal working conditions, the bearing temperature rise is not allowed to exceed 50℃, and the maximum temperature shall not be greater than 80C. >500
6080°
>500~1000
JB/T 5945 -1991
After assembly, the shaft must be able to operate flexibly. The axial clearance of the shaft shall comply with the provisions of Table 4. 3.4.6
Axial clearance of shaft
Bearing spacing height
Axial clearance
Axial clearancemax
3.5 Assembly of sprocket and chain
≤400
3.5.1After the sprocket is installed, axial play is not allowed. >400~630
>630~1000
>1000~1600
3.5.2 The geometric center planes of the active and passive sprocket tooth widths should coincide, and the offset should not be greater than 2/1000 of the center distance between the two sprockets, as shown in the figure below.
2A/1000
3.5.3 The chain and sprocket must be cleaned before assembly. If the purchased chain is well packaged, the lubricant is not hardened and there is no dirt, it can be left unwashed, but it must be assembled immediately after unpacking.
3.5.4 When the chain is engaged with the sprocket, the working side must be tightened; when working, the chain and sprocket should be engaged smoothly. 3.5.5 The droop of the non-working side of the chain should be within 1% to 5% of the center distance between the two sprockets. 3.5.6 If there is no special connecting ring at the connection of the chain, pins can be used for light riveting, but a steel stamp indicating light rivet pins must be stamped on the ring surface at the end.
3.6 Assembly of keys
3.6.1 During assembly, do not use a hammer to strike the key directly. When striking, a soft metal pad or a pad that is not easy to damage the key surface must be placed in the middle. When assembling a flat key, the key and the two sides of the shaft groove should be in uniform contact, and there should be no gap between the mating surfaces, and the two ends should not be raised. 3.6.2
3.6.3 After the hook key and the wedge key are assembled, the contact rate on the working surface should be above 70%. The remaining non-contact parts should not be concentrated in one section. Its exposed size should be 10% to 15% of the length of the bevel (the exposed size of the hook key does not include the hook head). 3.6.4 Splines and guide keys with clearance fit should slide freely after assembly, and there should be no local jamming and uneven tightness. 3.7 Assembly of gears and gearboxes
3.7.1 When hot-fitting gears, the heating temperature should not be greater than 250℃. 3.7.2
The axial misalignment of the meshing gears of the gearbox is allowed to be 4% of the gear width, but the maximum shall not exceed 2mm. After the gears are assembled, the contact points and side clearance of the teeth shall comply with the provisions of GB10095 and GB11365. After the gearbox is assembled, an idling test shall be carried out; during the test, the speed shall be from low speed to high speed, and the time for each gear shall not be less than 5 minutes, and the total running-in time shall not be less than 30 minutes. Check the following items: a.
When the gears are shifted, there shall be no biting or blocking, the speed change mechanism shall be flexible and accurate, and there shall be no automatic gear shifting or gear jumping; there shall be no abnormal sound during the operation of the gears;
The joints of the gearbox joint surface, screw plug, etc. shall not leak oil; there shall be no looseness at the joints of the various parts. 3.7.5 During the load test, the temperature rise of the gearbox shall not be greater than 50℃, and the maximum temperature shall not be greater than 90℃. 3.7.6
After the test, the oil shall be drained and thoroughly cleaned. Assembly of brakes and clutches
JB/T 5945 -1991
3.8.1 The assembly of caliper disc brakes shall comply with the relevant provisions of JB/T5948. 3.8.2 The assembly of band brakes shall comply with the relevant provisions of ZBJ85017. 3.8.3 The assembly of screen brakes shall comply with the relevant provisions of JB/T5949. 3.8.4 The plate friction clutch shall not slip or heat up when engaged, and the active drum and the passive drum must be completely separated when released. 3.8.5 The dry friction plate must be dry and clean, and no oil or debris is allowed on the working surface. 3.9 Assembly of couplings
3.9.1 The assembly of double universal couplings shall comply with the provisions of ZBJ85018. 3.9.2 The coaxiality of the two connecting shafts and the parallelism of the two end faces of the coupling shall comply with the provisions of Table 5. 3.10 Assembly of electrical system
The switches, relays and other components of the electrical system should be sensitive and reliable, easy to operate and maintain. The wiring of wires and cables should be correct, the connection should be firm and reliable, and there should be no cracks or cracks. Acidic flux should not be used in the welding parts of the wires, and the soldering joints should not be cold. Table 5
Coupling type
Cross slider type
Flexible claw type
Gear type
Elastic cylindrical pin type
Coupling diameter
>300~600
170~185
220~250
290~430
499~590
105~260
290~500
Coaxiality
End face parallelism
3.10.4 The wiring should be bundled and arranged beautifully. The wire ends should be marked. The parts of the wires that may be mechanically damaged should be protected by casings. No joints are allowed in the wires in the casings.
3.10.5 When the wire tube is bent or the length is greater than 800mm, it should be fixed with a pipe clamp or welded to the bracket. 3.11 Assembly of seals and application of sealants 3.11.1 Various seals such as felt rings, felt pads, asbestos ropes, leather cups, etc. must be soaked in oil before assembly. The copper pad is annealed (heated to 600-650℃ and cooled in water).
3.11.2 Various oil seals and sealing rings should be checked for damage before assembly. If necessary, lubricating grease should be applied to the oil seal buttocks, sealing ring surface and shaft.
3 When assembling oil seals and sealing rings, if they pass through keyways, screw holes or steps, protective measures should be taken to prevent damage to the oil seals 3.11.3
and sealing rings.
3.11.4 When using sealants, the parts must be cleaned with gasoline and blown dry before use. 3.12 Assembly of hydraulic system
Assembly.
Before assembly, all kinds of pipes and the inner wall of the container must be cleaned. If pickling is adopted, neutralization treatment should be carried out, and various pipes should not have defects such as rust, dents, folds, flattening and cracks, and the hoses should not be twisted. 3.12.3 Under working pressure, all pipe connections and seals should have good sealing performance, and oil seepage is not allowed at fixed interfaces, and oil leakage is not allowed at moving interfaces.
3.12.4 During assembly, the piston rod, cylinder barrel of the hydraulic cylinder and the valve stem, valve hole and other working surfaces of various valves shall not be damaged. 3.12.5 If the holes that are connected to the inner cavity of the exposed surface of the oil tank, hydraulic pump, hydraulic cylinder and hydraulic valve cannot be installed immediately, they should be sealed with special plugs or wrapped with plastic cloth. It is strictly forbidden to block them with cotton gauze, paper scraps and other objects. 4
JB/T 5945 - 1991
When hydraulic oil is injected into the oil tank, it must be filtered with a copper wire mesh of GFIW0.071/0.056 flat) 3.12.6
When the hydraulic system is working, there should be no abnormal noise and irregular impact sound. 3.12.8
The piston rod of the hydraulic cylinder and the inlet and outlet of the control valve support are not allowed to leak oil. 3.12.9
After the whole machine test, the test hydraulic oil must be released, the oil tank and oil filter must be cleaned, and new oil must be added. 0When the hydraulic system is working, the maximum temperature of the oil shall not exceed 80℃. 3.12.10
8Assembly of engineering machinery complete machine
3.13.1Purchased parts and outsourced parts must have a certificate of conformity. The manufacturer shall conduct sampling tests and can only be installed after confirming that they are qualified. 3.13.2 The oil, water and gas systems of the whole machine should all work properly. Before installation, the sealing of each component should be tested in accordance with the provisions of the relevant technical documents. No lubricating oil, water leakage or air leakage is allowed.
3.13.3 The appearance of the whole machine should be neat, beautiful and with clear outlines. The exposed machined surfaces and surfaces that need to be rust-proof should be cleaned and painted with anti-rust paint or anti-rust grease. The painting of all unprocessed surfaces, in addition to meeting the technical requirements indicated in the drawings, should meet the relevant provisions of JB/T5946.
Cleanliness of engineering machinery products
The technical indicators, measurement methods and inspection rules for the cleanliness of various engineering machinery complete machines and parts should meet the requirements of the corresponding complete machine and parts product quality classification standards.
4 Test methods
After the product is assembled, it should be tested according to the corresponding test standards and product test outline. 5 Inspection rules
The assembled products should be inspected and accepted by the manufacturer's quality inspection department drawings, relevant technical documents and this standard, and can only be put into storage after passing the inspection.
6 Marking, packaging, transportation and storage
6.1 Products that have passed the inspection should be accompanied by the logo of the manufacturer's quality inspection department. 6.2 Products should be accompanied by a certificate of conformity when leaving the factory, which must indicate: manufacturer name or code;
product name, model and specifications;
product factory number and date of manufacture.
6.3 Products should be protected or packaged after passing the inspection. 6.4 The protection, packaging, transportation and storage of the product shall comply with the provisions of the relevant standards or order agreements. 5
For the tightening torque of ordinary bolts, see Table A1.
Bolt strength grade
Bolt strength grade
Fixed strength
Flexed strength
Additional instructions:
230~290
290~350
384~512
512~683
740~880
864~1152
300~377
370~450
488~650
651~868
940~1120Www.bzxZ.net
JB/T5945 -1991
Replacement bolt tightening torque table
(reference part)
78~104
110~130
75~100
131~175
450~530
550~700
714~952
952~1269
1400~1650
1098~1464||t t||1606~2142
124~165
180210
209~278
540~680
680~850
969~1293
1293~1723
1700~2000
2181~2908
This standard is proposed and managed by Tianjin Engineering Machinery Research Institute of the Ministry of Machinery and Electronics Industry. This standard is drafted by Tianjin Engineering Machinery Research Institute of the Ministry of Machinery and Electronics Industry. The main drafter of this standard is Yang Chengshan.
90~110
110~140
145~193
193~257
280330
326~434
670~880
8251100
1319~1759||tt| |1759~2345
2473 ~ 3298 | | tt | | 2968 ~ 3958 | | tt | | 120 ~ 150 | | tt | | 150190 | | tt | 1120~1400
16 94~2259
2259~3012
2800~3350
3812~5082
170~210
210~270
282376
376~502
540~650
635~847
928 ~1237
1160~1546
1559~2079
2923~3898
4111~5481
4933~6577
People's Republic of China
Mechanical Industry Standard
Construction Machinery
General Technical Conditions for Assembly
JB/T 5945 -1991
Published by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing
Postal Code 100044)
Words: 12,000
Format: 880×1230
Print Sheet: 5/8
First Edition: March 1992
First Printing: March 1992
Print Quantity: 1-500
Price: RMB 10.00
Mechanical Industry Standards Service Network: http://www.JB.ac.cn1661- 6
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