JB/T 8874-2000 JB/T 8874-2000 Technical conditions for rolling bearing seats JB/T8874-2000 Standard download decompression password: www.bzxz.net

JCS 21.t00.20
Machinery Industry Standard of the People's Republic of China
JB/T8874-2000
Rolling Bearing Seats
Technical Conditions
Plummer block housings for rolling bearingsSpecifications
2000-04-24 Issued
Issued by the State Bureau of Machinery Industry
2000-10-01 Implementation
JB/874—2000
This standard is a downgrade of JB R874—1999. The original standard was revised when it was revised. Compared with JB/T8874—1999, the main technical contents of this standard are as follows: 1. The method of measuring the shortness of the center height opening is selected; 2. The method of measuring the geometric tolerance is added.
This standard replaces JB 874-1999 from the date of implementation. This standard is proposed and managed by the National Rolling Bearing Standardization Technical Committee. The drafting unit of this standard: Qianfu Bearing Research Institute. The drafter of this standard: Rong Yuzhao.
This standard was first issued in 1979 and first stored as ZB1003-7 in 1987. In April 1999, the standard was revised to JB/T8874-1999.
Machinery Industry Standard of the People's Republic of China
Technical Conditions for Rolling Bearing Seats
Pimrar Blotk, Bousinga for Rolling Bearlags--Specificaslons
JB/7874-2000
F/F 8874--1444
This standard specifies the technical requirements for two-stud and four-stud partial bearing seats (hereinafter referred to as drawer seats) with dimensions in accordance with GB 73.
This standard applies to production inspection and user acceptance of bearing seats. 2 Referenced Standards
The texts contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were 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 27S—1993
GBT1184—1996
GB/T 1800.4~-1999
GB/T2828—1987
GB/T6930—1986
GB/T7813—1998| |tt||GB/T 8597—1988
GB/9435—198
3 Definition
Fit of rolling bearings with shafts and housings
Tolerances of shape and position, tolerances not specified
Limits and fit standards for tolerance grades and holes, limit deviations of shafts Table of batch inspection Count sampling procedures and sampling tables (applicable to inspection of reverse batches) Definition of rolling bearing tolerances
Glossary of rolling bearings
Dimensions of rolling bearing seats
Packaging of rolling bearings
Characteristics of cast iron
This standard adopts the definitions obtained from GB/6930 and GB4199. 4 The numbers and abbreviations are shown in [See [ ]
Except the following symbols, the symbols quoted in this standard are defined in GB/T7813: u: single diameter of the entire inner hole of the bearing:
D: single diameter deviation of the inner hole of the auxiliary bearing:
H: actual center height;
4F: actual center height deviation:
H: actual distance from the bottom wheel line of the inner hole of the bearing seat to the installation bottom surface, r, cylindricality of the inner hole of the bearing seat:
: verticality of the shoulder end face of the inner hole of the bearing seat to the inner hole: approved by the Ministry of Machinery Industry on April 24, 2000 and implemented on October 1, 2000
Ja'T BTd-208
: parallelism of the inner hole axis of the auxiliary bearing seat to the bottom drawing, Hua
5 Technical requirements www.bzxz.net
5. 1 Materials
The bearing seat shall be made of HT200 grey iron, whose mechanical properties shall not be lower than those specified in GB 9439. The bearing seat may also be made of other materials with the same or superior properties. 5.2 Tolerances
5.2.1 The limit deviation of the inner hole diameter D, of the bearing seat shall comply with H8 in Table A2 and Table A4 of GBT 275-1993. The cylindricality of the inner hole of the bearing seat and the verticality of the inner hole shall comply with the provisions of Table 6 of GB/T275-1993. 5.2.2 The limit height of the center of the bearing seat 4H shall comply with the provisions of h13 in Table 22 of GB/T1800.4-1999. 5.2.3 The parallelism of the axis of the inner hole of the bearing seat to the bottom surface shall comply with the tolerance value of the 8th grade specified in Table B3 of GB/T1184-1996.
5.2.4 Other dimensions: hole according to 1I14: shaft according to h14: joint ±IT14/2 5.3 Surface roughness
5.3.1 The surface roughness of the inner hole and the shoulder of the bearing seat shall comply with the provisions of Table 1 of GB/T275-1993. 5.3.7 The maximum value of the surface roughness R of the bottom surface of the bearing seat cover and the base and the bottom surface of the bearing seat is 6.3μm. 5. Requirements for performance
5.4.1 The molding sand, mold, marks and scars on the bearing seat should be cleaned up, and the rough surface after cleaning should be flat and smooth. 5.4.2 The surface of the bearing seat is not allowed to have cracks, pores, shrinkage holes, holes, sand inclusions, insufficient casting and other defects that can reduce the strength of the bearing seat and obviously damage the appearance. Small defects that do not damage the strength and appearance of the bearing seat can be left unfinished, but the number and size of the defects shall be determined by the subscriber and the manufacturer.
5.4.3 The fonts on the bearing seat (such as the bearing seat model, manufacturer's logo, etc.) should be complete, clear and smooth. 5.4 The bearing seat casting should be aged before machining. 2
JB/F8874--20
5.4, 5 Bearing maintenance: After the cover and the base are matched, there shall be no obvious misalignment in their volume and shape: there shall be no obvious eccentricity between the inner hole of the bearing and its casting outer hole: there shall be no obvious offset between the shaft
5. 5 Others
5.5.! The surface of the bearing seat with T-point shall not have sand holes, burrs and sharp edges. 5.5. The outer surface of the bearing seat shall be coated with oil or paint, and the internal non-T-point surface shall be coated with anti-rust paint; the paint is sold at a price that is determined by the factory or through consultation with the subscriber. 5.5.3 After the bearing seat is inspected and qualified, the cast iron anti-fouling agent shall be removed from the surface of the bearing seat, and a hard paper baffle shall be placed in the felt groove to prevent dust and debris from invading. 6 Measurement method 6.1 Tolerance measurement 6.1.1 Inner hole measurement 6.1.1.1 Inner diameter test Fix the upper and lower parts with a screw, and then measure the middle of the inner hole according to the two-point profiling method. (,1.1.2 Measuring the inner diameter and the inner hole verticality The inner diameter is measured at the same position on the whole inner hole according to the two-point measurement method. Figure DD... Measuring the inner hole verticality at both ends: Insert the standard part into the bearing seat, and then fix the upper cover and the base with bolts (tighten slightly), and use a feeler gauge to measure the distance between the end face of the standard part and the two shoulders of the inner hole of the bearing seat. The maximum value and the minimum value are the end face verticality. 6,1.2 Center height of the auxiliary plate
6.1.2.1 Center height measurement (2)
When measuring the center height, place the base of the bearing on the platform, Use a commercial measuring instrument to measure the actual distance between the wheel line at the bottom of the bearing library and the table surface, and modify formula (1) to calculate the actual center height H: H-H_-D,J/2
61.2.2 Measuring plate for parallelism of center line to bottom surface [see Figure 3] (door) Leave the base of the bearing seat on the platform, install the bearing that meets the user's requirements, put the spindle through the inner hole of the bearing, and use a high-base measuring instrument to measure, (the measurement points are shown in Figure 3), parallelism, = -,: the distance between the two ends of the spindle and the bottom surface; l: the distance between the two measuring points, g-2mm (the width of the inner hole of the vehicle) 3
6. 2. Roughness test of bearing seat JB/T8874-2000 The surface roughness of bearing seat is checked by comparing the roughness under the light. The inspection specification is as follows. 1. The bearing seat is inspected by the quality inspection department of the manufacturer before it leaves the factory. The qualified bearing seat is accompanied by a quality certificate. 7.2 The sampling method for quality inspection of bearing seat shall be in accordance with the provisions of GB/12828. The qualified quality level AQL value of the main items is 2.5 and the qualified quality level AQL value of the secondary items is 4.0, check the water card is set as a level 1: the main, secondary inspection items see table! : Table
Main inspection items
Inner hole point light, the plate limit deviation D
Nezha Adudu!
Internal bearing seat
Internal matching surface tolerance
Mold difference between the center and the screen
Parallelism of the inner center line to the screen surface
Marking, packaging and storage
Main inspection items
Others 1. Surface twist
Appearance quality
e.1 The model and manufacturer code (or trademark) should be marked on the bearing seat, and its position and size should comply with the requirements of the product drawings. 8.2 The finished bearing seat that has passed the final inspection shall be packaged in accordance with GB/T8597. 8.3 Under the condition of complying with the storage and preservation regulations of the product, it is guaranteed not to rust within 10 years. The anti-rust period is calculated from the date of production.
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