JB/T 7907-1999 This standard is a revision of JB/T 7907-95 "Technical Conditions for Powder Metallurgy Oil Pump Gears". This standard specifies the technical requirements, test methods, inspection rules, etc. for powder metallurgy oil pump gears. This standard applies to powder metallurgy gears (external involute spur gears) for internal combustion engine oil pumps with a working oil pressure not exceeding 1.2MPa. This standard was first issued in 1982 as NJ 260-82, first revised to GB 10426-89 on February 11, 1989, and adjusted to JB/T 7907-95 on April 14, 1996. JB/T 7907-1999 Technical Conditions for Powder Metallurgy Oil Pump Gears JB/T7907-1999 Standard Download Decompression Password: www.bzxz.net

ICS 77.160
Machinery Industry Standard of the People's Republic of China
JB/T7907-1999
Powder Metallurgy Oil Pump Gears
Technical Conditions
Specifications for powder metallurgy oil pump gears1999-08-06 Issued
National Bureau of Machinery Industry
2000-01-01 Implementation
JB/T7907-1999
This standard is an editorial revision of JB/T7907--95 "Powder Metallurgy Oil Pump Gears". The main technical content has not changed. This standard replaces JB/T7907--95 from the date of implementation. Appendix A of this standard is the appendix of the standard.
Technical Conditions" revision. During the revision, the original standard was revised. This standard was proposed and managed by the Technical Committee for Standardization of Powder Metallurgy Products. This standard was drafted by: Hangzhou Powder Metallurgy Research Institute. The main drafters of this standard are: He Wanluo, Zhang Xianbin. This standard was first issued in 1982 as NJ260--82, and was revised for the first time on February 11, 1989 as GB10426-89. In April 1996, the standard number was adjusted to JB/T7907-95. Scope
Machinery Industry Standard of the People's Republic of China
Powder Metallurgy Oil Pump Gears
Technical Conditions
Specificationsforpowdermetallurgyoilpumpgears This standard specifies the technical requirements, test methods and inspection rules for powder metallurgy oil pump gears. JB/T 7907-1999
Replaces JB/T7907-95
This standard applies to powder metallurgy gears (external involute spur gears, hereinafter referred to as gears) for internal combustion engine oil pumps with a working oil pressure not exceeding 1.2MPa.
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/T 223.11981
GB/T 1031—1995
GB/T 1184-1996
GB/T 5163—1985
GB/T9097.1—1988
GB/T10095—1988
JB/T 2798—1999
JB/T7905—1999
Technical requirements
Determination of carbon content in steel and alloys
Surface roughness parameters and their valueswwW.bzxz.Net
Tolerances for shape and position without tolerance values
Permeability Sintered metal materials—Determination of density Determination of apparent hardness of sintered metal materials (excluding hard alloys) Part 1: Materials with basically uniform cross-sectional hardness
Precision of involute cylindrical gears
Sintered iron-based powder metallurgy products
Metallographic standards
Sintered metal materials (excluding hard alloys)—Sampling Gears shall comply with the provisions of this standard and shall be manufactured in accordance with product drawings and technical documents approved through prescribed procedures. The chemical composition of gear materials shall comply with the provisions of Table 1. Table 1
The physical and mechanical properties of gears shall comply with the provisions of Table 2. Item Month
Density (without oil)
Tooth root bending strength
≥210
Approved by the State Machinery Industry Bureau on August 6, 1999Total carbon
Combined carbon
Microstructure
Spherulite not less than 50%.
Free cementite not less than 5%
Implemented on January 1, 2000
3.4 ​​Dimensions and geometric tolerances of gears
JB/I7907—1999
3.4.1 The manufacturing accuracy of gears shall comply with the 8th grade specified in GB/T10095. 3.4.2 The coaxiality of the outer cylindrical surface of the gear to the center line of the matching hole shall comply with the 8th grade specified in GB/T1184. 3.4.3 The runout of the gear end surface to the center line of the matching hole shall comply with the 8th grade specified in GB/T1184. 3.5 Surface roughness of gear
3.5.1 The surface roughness of gear tooth surface shall be R, 12.5μm as specified in GB/T1031. 3.5.2 The surface roughness of gear end face shall be R, 0.8μm as specified in GB/T1031. The surface roughness of outer cylindrical surface of gear shall be R, 1.6μm as specified in GB/T1031. 3.5.3
The surface roughness of gear matching hole shall be R, 3.2μm as specified in GB/T1031. 3.6 Appearance
The appearance of gear shall be free from serious defects such as damage and cracks. 3.6.11
The appearance of gear shall be free from oxidation, bruises and inclusions. 3.6.2
Sharp corners and burrs shall be eliminated from machined gears. 3.6.3
3.7 Service life
The service life of gear shall not be less than 2000h of main engine operation. Test method
4.1 The carbon content of gears shall be determined according to the method specified in GB/T223.1. Combined carbon shall be calculated according to formula (1):
Ccarbon=Cth-Cth
Wherein: Carbon—combined carbon content, %;
Ctotal—total carbon content, %;
Free carbon content, %.
4.2 Test of tooth root bending strength
The test method is shown in Figure 1. The F force should act on the intersection of the gear pitch circle and the tooth surface, and be perpendicular to the gear tooth section passing through this intersection. 4.2.1.
4.2.2 The tooth root bending strength is calculated according to formula (2): Gp
Where: T
-tooth root bending strength, MPa:
FcosaY,h
F tooth bending force, N;
b-tooth width, mm:
m--module, mm;
α-pressure angle;
h-tooth root height, mm;
JB/T7907-1999
Y-tooth shape coefficient, see Appendix A (Standard Appendix). 4.2.3 Tooth root bending strength test If the hub breaks first due to the gear structure size (not manufacturing factors). The test method is allowed to be agreed upon by the supply and demand parties.
4.3 Hardness shall be inspected in accordance with the provisions of GB/T9097.1. Density (without oil) shall be measured in accordance with the provisions of GB/T5163. 4.4
Microstructure shall be evaluated in accordance with the provisions of JB/T2798. 4.5
5 Inspection rules
Gears shall be inspected by the quality management department of the manufacturing unit in accordance with the provisions of this standard and the requirements of relevant technical documents before leaving the factory. Users shall randomly inspect the quality of gears in accordance with the provisions of JB/T7905. The sampling plan and the acceptable quality level (AQL) shall be agreed upon by both parties. Randomly select two teeth for gear microstructure evaluation, which shall be carried out on the section at 1/3 of the tooth width. The manufacturing accuracy of the gear shall be measured by any one of the inspection groups listed in Table 3. The measurement results of the two inspection groups have equal validity. Table 3
Inspection group
Tolerance group
5.5 Surface roughness can be visually inspected against the standard sample block. 6 Marking, packaging, transportation and storage
F' and F
6.1 Gears must be cleaned and treated with rust prevention before packaging, and then packed with strong and impermeable neutral paper, and then several gears are placed in a cardboard box. The box should be accompanied by a product certificate and instruction manual signed by the quality inspector. The outer surface of the box should be marked with: a) manufacturer name;
b) product name;
c) product model or mark;
d) manufacturing date (or number) and production batch number. 6.2 Gears packed in cartons must be placed in dry wooden boxes with waterproof paper or moisture-proof cartons to ensure that the packages are not scattered and the parts are not damaged during normal transportation. The total weight of a single box shall not exceed 25kg. The outer surface of the box should be marked with: a) manufacturer's name and address; b) product name, model and quantity; c) packing date, gross weight and net weight; d) shipping address and consignee; e) "handle with care" and "afraid of moisture" or mark. 3 Gears should be stored in a dry warehouse. Under normal storage conditions, if rust occurs within half a year from the date of leaving the factory, the manufacturer 6.3 shall be responsible for replacement. JB/T7907-1999 Appendix A (Standard Appendix) Tooth shape coefficient chart A1 Tooth shape coefficient Y in the calculation formula for tooth root bending strength,The value can be found in Figure A1. Mengtong
Tooth shape coefficient Y
40506080
100400
2 (z,)
People's Republic of China
Mechanical Industry Standard
Powder Metallurgy Oil Pump Gear
Technical Conditions
JB/T 7907-1999
Published by the Mechanical Science Research Institute
Printed by the Mechanical Science Research Institute
(No. 2, Shouti South Road, Beijing
Format: 880×1230
Postal Code: 100044)
Printing Sheet: 1/2
Word Count: 12,000
First Printing in March 2000
First Edition in March 2000
Print Quantity: 1-500
Price: 5.00 Yuan
99-1188
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