This standard specifies the determination method and objective evaluation value of the cleanliness of gear transmission devices with separate housings for transmitting power, and is applicable to the acceptance of products before leaving the factory and after overhaul. This standard does not apply to gear transmission devices with grease lubrication and centralized circulation lubrication. JB/T 7929-1999 Cleanliness of gear transmission devices JB/T7929-1999 Standard download decompression password: www.bzxz.net

JB/T7929
This standard is a revision of JB/T7929-1995 "Cleanliness of gear transmission devices". During the revision, only editorial changes were made according to relevant regulations, and the main technical content remained unchanged.
This standard replaces JB/T7929-1995 from the date of implementation. This standard is proposed and managed by the National Technical Committee for Gear Standardization. The responsible drafting unit of this standard: Zhengzhou Machinery Research Institute. The main drafters of this standard: Guo Xiaoqun, Qian Zhenxuan, Chen Linghao, Yang Wei, Zhang Yuanguo, Wang Qi.
This standard was first issued in 1989 as GB11368-89 and was adjusted to JB/T792995651 on April 14, 1996.
1 Scope
Mechanical Industry Standard of the People's Republic of China
Cleanliness for gear drive
Cleanliness for gear drive unitsJB/T7929-..1999
Replaces J3/79291995
The cleanliness of gear transmission is measured by weight of impurities collected from the inner cavity of the gear box by a specified method. Product quality assessment index
This standard specifies the determination method and objective evaluation value of the cleanliness of gear transmission devices with a separate housing for transmitting power. It is applicable to the acceptance of products after delivery and overhaul.
This standard is not applicable to gear transmission devices with grease lubrication and centralized circulating oil lubrication. This standard allows the acceptance of gear transmission devices based on the cleanliness conditions determined by the agreement or order contract between the manufacturer and the user. 2 Reference standards
The provisions contained in the following standards constitute the provisions of this standard by reference in this standard. The versions shown are valid when this standard is published. All standards will be revised, and parties using this standard should explore the possibility of using the latest versions of the following standards. GB/T6004-~1985 Metal wire woven square mesh for test sieves GB/T 1922—1980 Solvent oil
3 Determination method
3.1 Apparatus, equipment and cleaning fluid for determination
3.1.1 Apparatus
) Brush: including various large round, conical, oblate nylon brushes, etc.: b) Filter: SSW0.063/0.045GB/T6004 (equivalent to British 235 mesh/in). SSW0.032/0.028GB/T 6004 (equivalent to British 423 mesh/in);
) Necessary containers and tools
3.1.2 Equipment
a) Analytical balance with a sensitivity of 1/10000g; b) Oven;
) Drying oven
3.1.3 Cleaning liquid
Solvent oil (NY-120GB/T1922 is recommended), kerosene and acetone. 3.2 Sampling operation procedures
3.2.1 Preparation
α) The entire measurement must be carried out in a dry, clean and safe room; h) The operator's clothes and hands should be clean;
C) The non-measurement parts, i.e. the outer surfaces of the gear shaft, shaft end and end cover exposed outside the box, should be cleaned; d) All sampling tools and containers should be cleaned and free of foreign matter. National Measurement: Approved by the State Bureau of Machinery Industry on June 24, 1999 62
Implemented on January 1, 2000
JB/T 7929
e) Use SSW0.032/0.028 to clean the filter and filter NY-120 solvent oil, kerosene and acetone in turn. f) Soak the SSW0.063/0.045 filter in NY-120 solvent oil for 10 minutes and take it out. After the solvent oil evaporates, put it in a 105 (+ 5°C oven for 30 minutes, take it out, put it in a dryer to cool for 60 minutes, and then weigh it on a balance with a sensitivity of 1/10000g. Repeat the above drying, cooling and weighing process for the filter several times until the difference between the two weighings does not exceed 1/10 (000 product. The weight is recorded as G.||tt| |3.2.2 Sampling steps
3.2.2.1 Control the input shaft speed of the gear device to 60% of the rated speed, operate it at high gear and no load for 30 minutes, and collect all the oil samples in the gear device when the oil temperature is not higher than 65 (.
3.2.2.2 Then inject kerosene that is not less than 50% of the volume of the lubricating oil to be injected into the gear device, operate it for 2 minutes according to the operating conditions in 3.2.2.1, and collect all the kerosene samples, including the impurities on the magnetic screw plug. 3.2.2.3 Disassemble all the detachable parts of the gear device, carefully clean the inner surface of the box and the inner holes and surfaces of all parts with a brush and solvent oil, and collect all the cleaned
3.2.2.4 During the oil sample collection and cleaning process, the oil sample and cleaning liquid should be prevented from splashing and spilling. 3.2.2.5 Use SSW0.063/0.045 constant weight filter to filter all the collected oil samples and cleaning liquid. 3.2.2.6 Soak the filter containing impurities in solvent oil and acetone for 20 minutes each. 3.2.2.7 Put the filter containing impurities soaked in cleaning liquid into a 105℃ ± 5 (oven for 60 minutes, take it out and cool it in a desiccator for 60 minutes, and then weigh it on a balance with a sensitivity of 1/10000g. Repeat the above drying, cooling and weighing for the filter containing impurities several times. Process. Until the difference between the two weighings does not exceed 4/10000g, record this amount as G2. 3.3 Calculation of impurity mass
The impurity mass is calculated according to formula (1).
Where: (—- mass of impurities, mg; bzxz.net
G, — weight of the filter, mg;
(z———mass of the filter together with the impurities, mg. 4 Objective evaluation standard
The objective evaluation value of the cleanliness of the gear transmission device is the impurity content per unit volume of lubricating oil that should be filled in the box. It is divided into 16 levels, including A, 3, C, D, E, F, G, H, J, K, M, N, P, Q, R, and S. The value range of each level is shown in Table 1. Table 1 Objective evaluation value level of cleanliness of gear transmission device
Objective evaluation value
>0. 25 ~0. 50
>0. 50~1. 00
1. 00~2. 00
>2. 00~-4. 00
4. 00~-8. 00
>8. 00-~14. 00
214. 00-~~24. 50
>24. 50~-43. 00
Objective evaluation value
243. 00-.75. 00
75. 00--.
132. 00--.197. 00 | | tt |
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