JB/T 7048-1993 Technical conditions for engineering plastic cages of rolling bearings JB/T7048-1993 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
JB/T7048-1993
Rolling bearings
Engineering plastic cages
Technical conditions
Published on September 23, 1993
Ministry of Machinery Industry of the People's Republic of China
Implementation on July 1, 1994
Mechanical Industry Standard of the People's Republic of China
Rolling bearings
Engineering plastic cages
Technical conditions
Subject content and scope of application
JB/T 7048-1993
This standard specifies the materials, technical requirements, inspection methods and inspection rules for engineering plastic cages of rolling bearings. This standard applies to the manufacture, inspection and user acceptance of the following types of bearing engineering plastic cages with an operating temperature range of -30℃~+120℃.
d. Self-aligning ball bearings with a value of less than 0.6x10°mmr/min; cylindrical roller bearings with an outer diameter of less than 240mm; self-aligning roller bearings with an outer diameter of less than 320mm; angular contact ball bearings with a value of less than 0.6x10°mmr/min and a contact angle of ≤40° 2
Reference standards
GB1039
GB1040
GB8597
JB/T6638
ZBJ11020
Symbols and terms
3.1 Symbols
General principles for test methods for mechanical properties of plastics| |tt||Plastic tensile test method
Rolling bearing packaging
Technical conditions for glass fiber reinforced polyamide 66 for rolling bearing cage Inspection rules for rolling bearings and their commercial parts Nominal inner diameter of cage
Nominal outer diameter of cage
Cage center circle diameter
Nominal width of cage
Cage ball pocket diameter
Cage window hole diameter
Cage hole or lock diameter
Cage pocket or window hole number
Distance between the centers of two adjacent pockets or windows of cage Lc—Cage window hole width
Symbols see Figures 1 and 2.
Approved by the Ministry of Machinery Industry on September 23, 1993
Implemented on July 1, 1994
3.2 Terminology
JB/T70481993
Radial tensile strength of cage. The tensile stress value when the cage is damaged by applying radial tensile load to the cage. 4 Technical requirements
4.1 The cage material shall be GRPA66-25 material in accordance with the provisions of JB/T6638. Recycled materials are not allowed. 4.2 The dimensions and tolerances of the cage shall comply with the provisions of the product drawings. 2
JB/T7048-1993
4.3 During the injection molding of the cage, the mold must be heated and the temperature must be controlled at 80~90℃. 4.4 The cage product after injection molding should be stabilized. The conditions for stabilization treatment are medium air temperature of 100±2℃ and time of 1h. 4.5
Other technical requirements for cages shall be as specified in Table 1. Table 1
5 Inspection method
Radial tensile strengtha
Rotational flexibility
Rolling element retention
Surface quality
5.1 Radial tensile strength
>65MPa (dry state)
Technical requirements
The rolling element should be able to rotate freely in the cage pocket or window hole. After being installed in the bearing, the bearing should rotate flexibly without obstructionwww.bzxz.net
The rolling element should lock itself when installed in the cage pocket or window hole and should not be separated from the cagea. The cage should be intact, with a flat and smooth surface. No defects such as overflow, burrs, cracks, streaks, dents, peeling, delamination, warping and obvious welding marks are allowed.b. The surface of the cage pocket or window hole should be bright, and no bubbles or impurities are allowed inside.c. The color of the cage should be uniform, and no oil, scale, dust, etc. are allowed on the surface of the cage. Follow the provisions of Appendix A (Supplement). 5.2 Rotational flexibility
The matching rolling element of the largest size group should not be stuck when installed in the cage pocket or window hole. Install it into the qualified inner and outer rings and rotate it by hand. The bearing should rotate flexibly without blocking. The cage should not touch the inner and outer rings (except for the cage guided by the rib). 5.3 Rolling element retention
The rolling element of the smallest size group among the matching rolling elements should not be separated from the cage in any direction.
5.4 Surface quality should be visually inspected.
5.5 Dimensions
5.5.1 The cage pocket diameter S@ and the window diameter Aa are measured with an internal diameter dial indicator with an accuracy of 0.01mm. 5.5.2 The cage J, Dcl, Dc, and Bc are measured with an electronic digital display vernier caliper with an accuracy of 0.01mm. 6 Inspection rules
6.1 The finished cage should be inspected by the quality inspection department of the manufacturer and the inspection report should be provided to the user. 6.2 The surface quality of the finished cage should be 100% inspected. 6.3 The cage should be accepted according to ZBJ11020. The acceptable quality level AQL of the main items (radial tensile strength, rotational flexibility, rolling element retention, and cage guide diameter deviation and guide diameter variation guided by the ring rib) is 2.5; the AQL of the secondary items (other items and dimensions) is 4.0; the sample size is drawn according to the special inspection level S-3, and the acceptance and rejection judgment numbers Ac and Re are used for judgment.
Marking, packaging, transportation, storage
JB/T7048-1993
The cages that pass the final inspection should be rolled with wrapping paper and then packed into cartons or wooden boxes. The outer packaging should be in accordance with the provisions of GB8597.
7.2 The finished cage should be marked with the manufacturer's trademark or code and the matching bearing code. 7.3 The cage packaging box should be accompanied by the manufacturer's cage test report and product certificate. The certificate should indicate the product standard number, matching bearing code, quantity, manufacturer, factory date, inspector code, etc. 7.4 During transportation, the cage should be protected from moisture, water and extrusion. 7.5 The cage should be stored in a dry and ventilated warehouse that is not exposed to direct sunlight, and should not come into contact with acids and alkalis and should be kept away from heat sources. 4
A1 Test equipment and tension fixture
A1.1 Tensile testing machine
JB/T7048-1993
Appendix A
Test method for radial tensile strength of cage
(Supplement)
The error of indication shall not exceed 1%, the radial tensile fracture load of cage shall be between 15% and 85% of the scale range of the testing machine, and the tensile speed shall be 10±5mm/min
A1.2 Tensile fixture
The tensile fixture is composed of a tension fork, a pin, and two semicircular blocks (or two semiconical blocks), see Figure A1. Tensile fixtures with different geometric shapes are used for cages with different inner diameter geometries. Fork clamp
Cage
Schematic diagram of radial tension clamp for cage
State of cage specimen and test environment
JB/T 7048—1993
State of cage specimen and test environment are formulated in accordance with GB1039. A2.1 Test environment: temperature 25±2℃; relative humidity (65±5)%. A2.2 State of specimen: Test in dry state. A2.2.1 Extract the specimen from the newly formed cage and place it in a dryer for more than 24 hours before testing. A2.2.2 If the specimen is extracted in the warehouse, first place the specimen in an electric blast oven for drying. The drying conditions are 100~110℃ for 6 hours. Then take it out and place it in a dryer for more than 24 hours before testing. A3
Extraction of cage samples
From the cages produced in batches (each batch is not more than 10,000 pieces), extract 5 samples for each model and test them after state adjustment. Test method
Install the cage after state adjustment as shown in Figure A1 and test it according to the method specified in GB1040. A5
Calculation of cage radial tensile strength
Cage radial tensile strength α, calculated according to formula (A1), = P/S
Where:
Cage radial tensile strength, MPa or N/mm2; Cage radial tensile fracture load, N;
S—minimum axial cross-sectional area of ​​cage, mm2. A5.2 Calculation of the minimum axial cross-sectional area S of the cage A5.2.1 The cage S of the self-aligning ball bearing is calculated according to formula (A2) (see Figure A2) S = 2 (S rectangular ABOD-2S defective shape)
In the formula: S shape = cSR2/2-αvsR2-α?
Where α = 2 yuan/180arcsinAB/2SR
A5.2.2 Cylindrical roller bearing cage S is calculated according to formula (A3) (see Figure A2). S = 2(Dc Dc)(Dc Lc)
JB/T70481993
A5.2.3 Spherical roller bearing cage S is calculated according to formula (A4) (see Figure A3). S=2(S trapezoid ABCD+S trapezoid EFGH)
Angular contact ball bearing cage S is calculated according to formula (A5) (see Figure A4). A5.2.4
S=2 trapezoid ABCO,-S sector AO,D+S trapezoid EHGO:-S sector FO,G-(S,+S2)b]Where: S=αSR/2
Where α=Yuan/180arcsinB/SR
Additional notes:
This standard is proposed by the Rolling Bearing Industry Standardization Technical Committee. This standard is under the jurisdiction of Luoyang Bearing Research Institute of the Ministry of Machinery Industry. Figure A4
This standard was jointly drafted by Luoyang Bearing Research Institute, Harbin Bearing General Factory, and Wuxi Xizhu Bearing Plastic Cage Factory. The main drafters of this standard are Liu Yaying, Wei Min, Cai Genxi, Wu Zuhua, Liu Jinhai, and Shi Fengbo. (A4)
People's Republic of China
Mechanical Industry Standard
Rolling Bearing
Engineering Plastic Cage
Technical Article
JB/T 70481993
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 880×12301/16Printing Sheet 5/8Number of Words 12,000First Edition in May 1994
First Printing in May 1994
Print Quantity 1-1000
Price 6.00 Yuan
Mechanical Industry Standard Service Network: http://www.JB.ac.cn661_80
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