JB/T 2984.4-1999 This standard is a revision of JB/T 8294-95 "Drive Gear Segments for Crawler Bulldozers". During the revision, editorial changes were made in accordance with relevant regulations, and the technical content has changed slightly. This standard specifies the type, size, requirements, test methods and inspection rules of the drive gear segments of crawler bulldozers. This standard is applicable to the drive gear segments of crawler bulldozers with a power greater than or equal to 73.5kW, and can also be used as a reference for the drive gear segments of other crawler engineering machinery. This standard was first issued on March 31, 1989 as GB 10915-89 and was adjusted to JB/T 8294-95 in April 1996. JB/T 2984.4-1999 Drive Gear Segments for Crawler Bulldozers JB/T2984.4-1999 Standard download decompression password: www.bzxz.net

ICS53.100
Machinery Industry Standard of the People's Republic of China
JB/T2984.4—1999
Crawler bulldozer Sprocket segment for drive
Crawler bulldozer Sprocket segment for drive1999-09-17Promulgated
State Machinery Industry Bureau
Implementation on 2000-01-01
JB/T2984.4—1999
This standard is a revision of JB/T829495 (formerly GB1091589) "Crawler bulldozer Sprocket segment". During the revision, the original standard was edited and the main technical content was slightly changed. Compared with JB/T8294-95, the main differences of this standard are: percentage sampling is abolished, and GB/T2828-1987 "Batch-by-Batch Inspection Count Sampling Procedure and Sampling Table (Applicable to Continuous Batch Inspection)" is implemented. This standard replaces JB/T8294-95 from the date of implementation. This standard is proposed and managed by the Engineering Machinery Standardization Technical Committee. The drafting units of this standard are: Tianjin Engineering Machinery Research Institute, Dandong 518 Internal Combustion Engine Parts Factory, Dalian Forging Factory, Shantui Engineering Machinery Company Industrial Company.
The main drafters of this standard are: Li Mingxiang, Wang Kaiyuan, Wang Ji Zeng, Guo Zhengde, Wu Lianfeng. 1
1Scope
Machinery Industry Standard of the People's Republic of China
Crawler bulldozer
Drive wheel gear segment
Crawler bulldozerSprocket segment for driveJB/T2984.4-1999
Replaces JB/T8294-95
This standard specifies the type, size, requirements, test methods and inspection rules of the drive wheel gear segment (hereinafter referred to as the gear segment) of crawler bulldozer. This standard is applicable to the drive wheel gear segment of crawler bulldozers with a power greater than or equal to 73.5kW (100 horsepower), and the drive wheel gear segment of other crawler engineering machinery can also be used as a reference. Cited 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 the parties using this standard should explore the possibility of using the latest version of the following standards GB/T 228—1987
GB/T2291994
GB/T230—1991
GB/T2828—1987
GB/T30T7—1999
GB/T10561—1989
JB/T2984.2—1999
JB/T2984.3—1999
3 Types and dimensions
Metal drawing Tensile test method
Metal Charpy notch impact test method
Metal Rockwell hardness test method
Count sampling procedure and sampling table for batch inspection (applicable to inspection of continuous batches) Technical conditions for alloy structural steel
Microscopic evaluation method for non-metallic inclusions in steel Crawler bulldozer driving wheel gear bolt Crawler bulldozer
Nuts for crawler and gear segment
3.1 The type and size of the gear segment shall comply with the requirements of Figure 1, Figure 2 and Table 1. Approved by the State Bureau of Machinery Industry on September 17, 1999 and implemented on January 1, 2000
JB/T2984.4—1999
Type A gear block (three teeth)
Figure 2 Type B gear block (two teeth)
Gear block pitch
Tooth top thickness
Tooth profile radius
Tooth top circle diameter
Tooth root circle diameter
Tooth sub-circle diameter
Stop diameter
Drilling center circle diameter
Drilling diameter
Drilling margin
Adjacent drilling holes
Interval drilling distance
Gear block Side clearance
Tooth surface width
Flange width
Marking example
JB/T2984.4-1999
Type A (three teeth)
203.2±0.7
According to the drawing
35.2±0.7
810.8±1.0
81.8±0.2
162.6±0.2
37.4±0.7
794.6±1.0
87.7±0.2
174.1±0.2
228.6± 0.7
39.5±0.7
1011±1.0
912.2±1.0
265 -05
92.9±0.2
184.5±02
Two-tooth B type, pitch is 216mm, the distance between adjacent mounting holes is 87.7mm, marked as: gear block B216×87.7
4 Requirements
JB/T2984.4—1999
Gear blocks should be manufactured in accordance with the product drawings, technical documents and this standard approved through the prescribed procedures. 4.1
Type B (two teeth)
37.4±0.7
794.6±1.0
The steel for gear blocks shall comply with the 40MnB or 35MnB alloy steel materials specified in GB/T3077. Other materials with mechanical properties not lower than the above grades are also allowed.
The carbon content of steel for gear blocks shall comply with the provisions of GB/T3077: its sulfur and phosphorus content shall be less than 0.035%. The content of non-metallic inclusions, brittle inclusions and plastic inclusions in steel shall comply with the requirements of Grade 2.5 specified in GB/T10561-1989. The mechanical properties and heat treatment requirements of gear blocks shall comply with the provisions of Table 2. Table 2
Tensile strength
≥932
Yield strength
≥735
Impact toughness
Surface hardness
37HRC or more Depth of hard layer at tooth root
37HRC or more Depth of hard layer at tooth top
The forging ratio of tooth block should be greater than or equal to 2, and the draft angle is 35°. The limit deviation of forging tooth profile accuracy relative to the standard tooth profile template should be controlled within ±0.7mm
JB/T2984.41999
4.7 Parts shall not have defects such as burrs, flash, folds, protrusions, oxide scales, misaligned molds and cracks, but a depression with a depth of no more than 0.15mm and an area of ​​no more than 1cm2 is allowed.
4.8 Forgings shall be shot peened and rust-proofed.
4.9 The surface roughness of the tooth block shall not exceed, and the surface roughness of the other non-machined surfaces shall not exceed 4.10 The hardenability of the steel shall comply with the provisions of Table 3 when quenching the extended forged specimen. Table 3
Distance from the quenching end
4.11 The bolts and nuts used with the tooth block shall comply with the provisions of JB/T2984.2 and JB/T2984.3. 5 Test methods
5.1 Tensile test
The tensile test of the finished tooth block shall be carried out in accordance with the provisions of GB/T228-1987. The No. 13 specimen in GB/T228-1987 shall be sampled from the finished product. The test sampling location is shown in Figure 3. B--B
Single mixing location
Figure 3 Tensile test sampling location
5.2 Impact test
The impact test of the tooth block shall be carried out in accordance with the provisions of GB/T229. The sampling position on the finished product is shown in Figure 4. In the high single sample package
Figure 4 Impact test sampling position
Hardness test
JB/T2984.41999
The hardness test of the tooth block shall be carried out in accordance with the provisions of GB/T230. The test position of surface hardness is shown in X, X,, X, and X in Figure 5. The test position of hard layer depth is shown in Y and Y, in Figure 5 (using hardness method). A--A
5.4 Flaw detection test
37HR core area
Figure 5 Surface hardness and hardened layer depth test position The finished tooth block is not allowed to have any cracks, and it shall be subjected to wet magnetic particle flaw detection and demagnetization treatment. 5.5 Material test
The tooth block material shall be subjected to spark test or metallographic microscopic evaluation test, and each batch shall be tested once. 5.6 Parallelism test of tooth root generatrix
The parallelism test of tooth root generatrix of gear block is shown in Figure 6. First adjust the clearance of the reference position to zero, and then measure the tooth root generatrix at the measuring position. The parallelism deviation is less than or equal to 0.7mm. Parallelism is always lowered
My corner room
Figure 6 Parallelism test of tooth root generatrix
5.7 Tooth profile accuracy test
Gear profile accuracy test is shown in Figure 7. First, evenly place the tooth profile template on the gear block to be tested, then raise the template by 1mm gap compared to the outer contour of the gear block tooth profile, and then measure the entire circumference of the gear block tooth profile (excluding the 4 points that are easy to contact near the tooth top in Figure 7). The gap should meet the requirement of (1±0.7)mm.
6 Inspection rules
JB/T2984.4—1999
Easy to contact constant + point
Figure 7 Schematic diagram of tooth profile accuracy test
6.1 The dimensional accuracy, surface roughness and appearance quality of the gear block shall be inspected by the inspection department of the manufacturer according to the product drawings and the provisions of this standard, and the factory certificate shall be issued before it is allowed to leave the factory. 6.2 The instruments and measuring tools used for inspection must be calibrated and qualified regularly. 6.3 Before the gear block leaves the factory, the finished products produced in batches shall be sampled and inspected. The sampling inspection method shall be in accordance with the provisions of GB/T2828. The non-conforming items that do not meet the requirements of Chapter 4 are divided into three categories of non-conforming items: Class A, Class B and Class C according to their impact on product quality. The qualified quality level AQL value, qualified judgment number Ac value and unqualified judgment number Re value are given respectively, and the normal one-time sampling plan is selected. The general inspection level I is adopted, the inspection batch N is selected from 26 to 50 pieces, the sample size code is D, and the sample size is & Class A AQL is 1.5, Ac is 0, Re is 1; Class B AQL is 40, Ac is 7, Re is 8: Class C AQL is 100, Ac is 14, Re is 15. 6.4 Sampling is carried out in a random manner. According to the sampling plan in 6.3, the samples are inspected item by item, and the results are summarized. 7 Packaging, transportation and storage
7.1 Before packaging, dirt and chips should be removed, the surface should be coated with rust inhibitor, and packed in a packaging box lined with moisture-proof paper, and it should be ensured that the gear block will not be damaged during normal transportation. The weight of a single box shall generally not exceed 60kg. 7.2 The packaging box should be accompanied by a certificate signed by the manufacturer's quality inspector, and the product name and model should be marked. 7.3 The packaging box should be marked with:
a) Product name and model;
b) Manufacturer's name:
c) Product specifications or marks;
d) Quantity:
e) Net weight:
f) Factory date.
7.4 After packing, the gear block should be placed in a dry and ventilated warehouse. Under normal circumstances, it should not rust within 1 year from the date of leaving the factory. 6
Mechanical Industry Standard
Drive Gear Segment of Crawler Bulldozer
JB/T29844—1999
Published and issued by the China Academy of Mechanical Science
Printed by the China Academy of Mechanical Science
(No. 2 Shouti South Road, Beijing: Postal Code 100044)*
Format 880×12301/16 Printing Sheet 3/4
4 Word Count 14.000bZxz.net
First Edition April 2000
First Printing April 2000
Print Quantity 1-500
Price 1000 Yuan
No. 99-1295
Mechanical Industry Standard Service Network: http/AvwwJB.ac.cn6
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