This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation, storage and quality assurance period for transfer cases for bulldozers. This standard applies to transfer cases for bulldozers with power of 88~170kW. JB/T 7305-1994 Technical requirements for transfer cases for bulldozers JB/T7305-1994 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7305-94
Transfer Case for Bulldozers
Technical Conditions
Published on July 18, 1994
Ministry of Machinery Industry of the People's Republic of China
Implemented on July 1, 1995
Mechanical Industry Standard of the People's Republic of China
Transfer Case for Bulldozers
1 Subject Content and Scope of Application
Technical Conditions
JB/T 730594
This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation, storage and quality assurance period for transfer cases for bulldozers.
This standard applies to transfer cases for bulldozers with a power of 88~170kW. 2 Referenced Standards
GB2828
GB10095
JB 3774.2
JB/T5937
JB/T5945
JB/T5946
JB/T5947
JB/T7158
3 Technical requirements
Batch inspection counting sampling procedures and sampling tables (applicable to continuous batch inspection) Involute male gear accuracy
Construction machinery noise measurement method
Construction machinery| |tt||General Technical Conditions for Gray Iron Castings
General Technical Conditions for Assembly
Engineering Machinery
General Technical Conditions for Painting of Engineering Machinery
General Technical Conditions for Packaging
Engineering Machinery
Engineering Machinery
Methods for Determining Cleanliness of Parts
3.1 The transfer case assembly shall comply with the requirements of this standard and be manufactured in accordance with the product drawings and technical documents approved by the prescribed procedures. 3.2 The surface of the transfer case shall be flat and shall not have defects such as rust, sand adhesion, excess meat and pouring and riser marks. 3.3 The gears of the transfer case assembly shall rotate flexibly and run smoothly without movement, impact, abnormal noise and blockage. 3.4 The lubricating oil channel of the transfer case shall not have stagnation after the pressure test. 3.5 The components of the transfer case assembly shall ensure that the lubricating oil channel is open and closed, and the lubrication of each bearing is reliable. 3.6 The noise value of the transfer case when fully loaded shall not be greater than 85dB(A). 3.7 When the material of the transfer case housing is gray cast iron, its manufacturing quality shall comply with the provisions of JB/T5937. When other materials are used, they shall comply with the provisions of relevant standards.
3.8 The gear accuracy, side clearance and contact spots of the transfer case shall comply with the provisions of GB10095. The gear accuracy level shall not be lower than level 8. 3.9 The cleanliness of the transfer case lubricating oil shall not be greater than 10mg/100mL. 3.10 All parts of the transfer case shall be inspected and meet the requirements of the drawings before assembly. Its assembly shall comply with the provisions of JB/T5945. Before assembling the transfer case, all parts shall be cleaned and the oil passage shall be clean and unobstructed. Rolling bearings and rotating parts shall be coated with appropriate amount of lubricating oil. 3.11
3.12 The strength of the bolts connecting the transfer case and the diesel engine shall not be lower than level 8.8. 3.13 When the transfer case works at an ambient temperature above 35C, the working temperature of its lubricating oil shall not be higher than 85C. 3.14 The transfer case shall be tested before leaving the factory, and the test time shall not be less than 5 minutes. 3.15 The non-machined surface of the transfer case shall be painted with anti-rust primer and topcoat, and the inner surface shall be painted with anti-rust paint. The painting shall comply with the provisions of JB/T5946. The color of the topcoat can be agreed with the user. Approved by the Ministry of Machinery Industry on July 18, 1994bZxz.net
Implementation on July 1, 1995
3.16 Reliability
JB/T 730594
With the main engine reliability operation for 1000 hours, the mean trouble-free working time MTBF shall not be less than 150b. 3.16.1
3.16.2 The transfer case's handleability effectiveness K value shall not be less than 85%. 3.16.3 Under normal use and maintenance conditions, the first overhaul period life shall not be less than 5000 hours. 4 Test method
4.1 Visual inspection is used for the appearance quality inspection of the transfer case and its components. 4.2 The test run of the transfer case is carried out on the running-in test bench. The method is to first apply an appropriate amount of lubricating oil on each moving friction surface, and then start the test bench under no-load conditions according to the provisions of Table 1. Table 1
300~500
4.3 The sealing test of the transfer case lubricating oil channel is to pass lubricating oil with a pressure of 0.3MPa into the oil channel and check for leakage after 3 minutes. 4.4 The gear spray gland is inspected with a gear gauge or micrometer. 4.5 The noise value is measured with a sound level meter and should comply with the provisions of JB3774.2. 4.6 The measurement of cleanliness should comply with the provisions of JB/T7158. 5 Inspection rules
The finished product shall be inspected by the quality inspection department of the manufacturer according to the drawings, relevant technical documents and this standard. After passing the inspection, the inspection certificate shall be issued before it is allowed to leave the factory.
5.2 Factory inspection
Each transfer case shall be inspected before delivery. The inspection items include: a.
Appearance quality and rotation stability;
Assembly correctness;
Sealing performance;
Completeness of random documents.
5.3 Type inspection
Type inspection shall be conducted every two years. Samples shall be randomly selected from batch products. The measured values ​​of type inspection shall comply with the product drawings and the provisions of this standard. The sampling inspection rules for transfer cases shall follow the provisions of GB2828. This standard selects the following schemes: Batch: 50 transfer cases are produced as a batch: Inspection level, general level! ;
Qualified quality level: AQL=4;
Strictness of sampling scheme: For normal inspection, transfer rules can be used: Sampling scheme type: One-time sampling scheme is adopted. When there are special requirements for the acceptance rules, the user and the manufacturer shall agree. 5.4
Marking, packaging, transportation and storage
6.1 When the transfer case is supplied as an independent product, there should be a label, which should indicate: a.
Manufacturer name or trademark:
Product name:
Product model and specifications;
Manufacturing date or production number.
JB/T 730594
6.2 The packaging of the transfer case shall comply with the provisions of JB/T5947. When the transfer case is transported, the surface shall not be damaged. 6.3
6.4 The qualified products shall be stored in a ventilated and dry room without corrosive media. 6.5 The product shall be accompanied by a product quality inspection certificate. The quality guarantee period is 18 months from the date of delivery (based on the date of delivery invoice) and the use time shall not exceed 2000 hours if the product is damaged or cannot work normally due to poor manufacturing quality. Additional remarks: This standard was proposed and managed by Tianjin Engineering Machinery Research Institute of the Ministry of Machinery Industry. This standard was drafted by Tianjin Engineering Machinery Research Institute and Wuxi Agricultural Machinery Factory. The main drafters of this standard are Xu Xiangshan, Ma Changxiao and Wang Tingxi.
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