GB/T 39743-2021 English PDF

US$344.00 · In stock
Delivery: <= 3 days. True-PDF full-copy in English will be manually translated and delivered via email.
GB/T 39743-2021: Plain bearings - Thermoplastic bushes - Dimensions and tolerances
Status: Valid

Standard ID	USD	BUY PDF	Lead-Days	Standard Title (Description)	Status
GB/T 39743-2021	344	Add to Cart	3 days	Plain bearings - Thermoplastic bushes - Dimensions and tolerances	Valid

Similar standards

GB/T 42613   GB/T 39333   GB/T 37677   GB/T 39741.2   GB/T 39741.1   

Basic data

Standard ID: GB/T 39743-2021 (GB/T39743-2021)
Description (Translated English): Plain bearings - Thermoplastic bushes - Dimensions and tolerances
Sector / Industry: National Standard (Recommended)
Classification of Chinese Standard: J12
Word Count Estimation: 18,133
Issuing agency(ies): State Administration for Market Regulation, China National Standardization Administration

GB/T 39743-2021: Plain bearings - Thermoplastic bushes - Dimensions and tolerances

---This is a DRAFT version for illustration, not a final translation. Full copy of true-PDF in English version (including equations, symbols, images, flow-chart, tables, and figures etc.) will be manually/carefully translated upon your order.
Plain bearings - Thermoplastic bushes - Dimensions and tolerances ICS 21.100.10 J12 National Standards of People's Republic of China Sliding bearing thermoplastic sleeve Dimensions and tolerances (ISO 16287.2005, IDT) Released on 2021-03-09 2021-10-01 implementation State Administration of Market Supervision and Administration Issued by the National Standardization Management Committee

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009. This standard adopts the translation method equivalent to ISO 16287.2005 "Sliding Bearing Thermoplastic Bushing Dimensions and Tolerances". The Chinese documents that have a consistent correspondence relationship with the normatively cited international documents in this standard are as follows. ---GB/T 1800.1-2020 Product Geometric Technical Specification (GPS) Linear Dimension Tolerance ISO Code System Part 1. The basis of tolerances, deviations and fits (ISO 286-1.2010, MOD) ---GB/T 12613.1-2011 Rolled sleeves of sliding bearings Part 1.Dimensions (ISO 3547-1.2006, IDT) ---GB/T 12613.2-2011 Rolled sleeves of sliding bearings Part 2.Test data of outer and inner diameters (ISO 3547-2. 2006, IDT) ---GB/T 23893-2009 Classification and marking of thermoplastic polymers for sliding bearings (ISO 6691.2000, IDT) ---GB/T 27939-2011 Quality control technology and inspection of sliding bearing geometry and material quality characteristics (ISO 12301. 2007, IDT) ---GB/T 35087-2018 Sliding bearing bushing lubricating oil hole, oil groove and oil pocket size, type, marking and application (ISO 12128.2001, IDT) Compared with ISO 16287.2005, this standard has made the following editorial changes. ---Modified the wrong form of the section lines in Figure 1, Figure 2 and Figure 3; --- Change the dimension mark "≤B" of the axial width of the bearing seat hole in Figure 3a) to "≥B", the original text is incorrectly marked; --- Change the dimension mark of the axial width of the bearing seat hole in Figure 3b) "≤B" to "≥(B-Bfl)", the original text is incorrectly marked; ---Added the informative appendix NA "Modified Thermoplastic Injection Molded Bushing Dimensions and Tolerances", and added relevant in the scope Description. This standard was proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Sliding Bearing Standardization Technical Committee (SAC/TC236). Drafting organizations of this standard. China Machinery Productivity Promotion Center, Zhejiang Changsheng Sliding Bearing Co., Ltd., Shanghai Institute of Materials, Zhejiang Double Feiwu Oil Bearing Co., Ltd., Zhejiang Zhongda Precision Components Co., Ltd., Hefei Bolin New Materials Co., Ltd., Jiashan Sanfu Sliding Bearing Co., Ltd. This standard is interpreted by the National Standardization Technical Committee for Sliding Bearings. Sliding bearing thermoplastic sleeve Dimensions and tolerances

1 Scope

This standard specifies the dimensions and specifications of press-in thermoplastic bushings with or without lubricating oil grooves produced in accordance with ISO 12128. difference. Thermoplastic bushings produced according to Table 2 and Table 3 and rolled bushings produced according to ISO 3547-1 are mutually compatible in size. Changed. This standard does not apply to reinforced plastic shaft sleeves. Note. Appendix NA gives the dimensions and tolerances of the modified thermoplastic injection molding bushing.

2 Normative references

The following documents are indispensable for the application of this document. For dated reference documents, only the dated version applies to this article Pieces. For undated reference documents, the latest version (including all amendments) is applicable to this document. ISO 286-1 ISO Limits and Fit System Part 1.Tolerances, Deviations and Basis of Fit (ISO system of limits and fits-Part 1.Basesoftolerance, deviationsandfits) ISO 554 Standard environmental specifications for conditioning and/or testing (Standard atmospheres for conditioning and/or testing-Specifications) ISO 3547-1 Plain bearing-Wrapped bushes-Part 1.Dimensions (Plainbearings-Wrappedbushes-Part 1. Dimensions) ISO 3547-2.1999 Rolled sleeves of plain bearings Part 2.Test data of outer and inner diameters (Plainbearings- Wrappedbushes-Part 2.Testdataforoutsideandinsidediameter) ISO 6691 Classification and marking of thermoplastic polymers for sliding bearings (Thermoplasticspolymersforplain bearings-Classificationanddesignation) ISO 12128 sliding bearing bushing lubricating hole, oil groove and oil pocket size, type, marking and application (Plainbearings- Lubricationholes,groovesandpockets-Dimensions,types,designationandtheirapplicationtobear- ingbushes) ISO 12301 Plainbearings-Quality Quality Control Technology and Inspection (Plainbearings-Quality controltechniquesandinspectionofgeometricalandmaterialqualitycharacteristics)

3 symbols

The following symbols apply to this document. B Bushing width Bfl flange thickness Ci inner chamfer Co outer chamfer Dfl flange diameter DH bearing seat hole diameter Di shaft sleeve inner diameter Di,ch The inner diameter of the bushing after being pressed into the ring gauge with tolerance class H7 Do shaft sleeve outer diameter size r Flange sleeve fillet radius

4 Dimensions and tolerances

According to the distinction between cylindrical bushings (C type) and flange bushings (F type), the dimensions and tolerances of the thermoplastic bushings shown in Figure 1 and Figure 2 Given in Table 1, Table 2, Table 3 and Table 4, the unit is mm. The surface roughness indicated by x and y in Figure 1 and Figure 2 are given in Table 5. The coaxiality tolerance value of the outer diameter Do can be determined by checking the standard tolerance value (see ISO 286-1). The tolerance value of the end face circle runout of the flange diameter Dfl can be determined by checking the standard tolerance value (see ISO 286-1). Table 4 Nominal dimensions and limit deviations of F-type thin-walled flange bushings for width B conforming to ISO 3547-1 Inner diameter Di Nominal size Outer diameter Do Nominal size Tolerance group limit deviation Poor (see Table 5) AB Flange diameter Dfl h13 Flange thickness Bfl h13 Bushing width h13 Chamfer Ci Co max Fillet radius max 0.21 0.07 0.27 0.09 0.33 0.11 0.45 0.15 0.60 0.20 0.69 0.23 0.90 0.30 zb11 12 1 4 8--0.8 0.5 15 1 5.5 7.5 9.5-0.8 0.5 18 1 7 9 12 17 0.8 0.5 20 1 7 9 12 17 0.8 0.8 22 1 12 17--0.8 0.8 23 1 9 12 17-0.8 0.8 24 1 12 17--0.8 0.8 26 1 12 17 22-0.8 0.8 30 1.5 11.5 16.5 21.5-1.5 0.8 35 1.5 11.5 16.5 21.5-1.5 0.8 42 2 16 26--2 0.8 47 2 16 26--2 0.8 53 2 16 26--2 0.8 58 2.5 16 26--2.5 0.8 According to Table 1, Table 2 and Table 3, if it is necessary to use a non-standard value for width B, the last digit should be 0, 2, 5 or 8. The chamfer Ci can also choose a 45° angle. The chamfer Co can also be replaced by a fillet radius r. For different materials, the wall thickness should be a fixed value, and the inner diameter tolerance of the shaft sleeve after assembly should be within the tolerance level of F10~D12. For flange diameter Dfl, the recommended tolerance is d13.Other tolerances up to h13 are allowed and should be subject to suppliers and purchasers The agreement reached.

5 materials

Use thermoplastics that meet the requirements of ISO 6691, such as. PA, PET, PE, POM. For modified materials or other materials, the details should be subject to the agreement reached between the supplier and the purchaser. Note. Thermoplastics have a higher linear expansion coefficient than metals, and PA (nylon) can absorb more water than other materials, so there will be Changed. According to the tolerance zone and fit specified in this standard, these properties are considered under the following conditions. a) The bearing clearance is designed to be when the sleeve working temperature is between -10℃~50℃, and the relative humidity of the environment is 20% to 95%. gap. b) The interference fit of the bearing seat is achieved by the bearing bush press-in interference (the limit deviation of the outer diameter Do), and the working temperature is -10℃~ Keep the interference fit at 50°C. c) Table 1, Table 2, Table 3 and Table 4 are based on the value of the linear expansion coefficient of the shaft and the bearing seat in the range of 10×10-6/K~12×10-6/K. Under working conditions other than those listed above, the bearing clearance and installation form should be reviewed and confirmed. The tolerances have been noted It is effective under the conditions (such as the temperature and humidity in the environment in accordance with ISO 554-23/50). In order to maintain the size of the shaft sleeve, the shaft sleeve made of PA (nylon) material should be stored in the standard environment specified above or in a suitable In a sealed environment.

6 Design

The surface roughness and tolerance grade of tolerance group A or B should meet the requirements of Table 5. Table 5 Surface roughness and limit tolerance The edges and corners should be clear of burrs or burrs. Due to the large amount of press-in interference, the leading edge of the bearing housing should be chamfered or rounded to avoid damage when press-in the sleeve. Standard bushings (Type C and Type F) should have the smallest outer diameter chamfer and the smallest inner diameter chamfer on the two opposite end faces, respectively. If the supply and demand sides If an agreement is reached, additional chamfers can also be provided.

7 Detection

7.1 General The size of the sleeve should be measured under the specified conditions (see the note in Chapter 5). 7.2 Outer diameter Do a) Check the outer diameter of the bushing with two ring gauges. The general rules and stop rules respectively correspond to the outer diameters of the special composite thermoplastic bushings specified in Table 1 to Table 4 or provided by the supplier. Large limit size and minimum limit size. b) When measuring the outer diameter in a free state, it should be measured at least twice and the arithmetic average value (see ISO 12301) should be taken. 7.3 Inner diameter Di a) Check the inner diameter of the bushing with two ring gauges. The bushings are pressed into the two ring gauges in sequence, and the dimensions of the two ring gauges correspond to the maximum limit size and the maximum size of the bearing seat with tolerance class H7. Small limit size. When the ring gauge with the minimum tolerance limit size of the bearing seat is pressed in, the inner diameter of the shaft sleeve should not exceed the tolerance specified in Table 5. Limit size. When the ring gauge with the maximum tolerance limit size of the bearing seat is pressed in, the inner diameter of the shaft sleeve should not exceed the upper limit of the tolerance specified in Table 5. Limit size. The maximum and minimum inner diameter of the shaft sleeve should be checked with a through-stop gauge or measured with a three-contact inner diameter measuring instrument. b) Use a ring gauge to check the inner diameter of the bushing, which is consistent with ISO 3547-2.1999 Rolling Bushing Inspection Method C. Press the sleeve into the ring gauge. The size of the ring gauge is the rounded value of the outer diameter Do of the sleeve plus the average tolerance of the tolerance class H7. After the bushing is pressed into the ring gauge, the inner diameter Di,ch should be checked with a through-stop gauge or measured with a three-contact inner diameter measuring instrument. The width of the ring gauge should be slightly larger than the width of the shaft sleeve. When checking the inner diameter of the shaft sleeve, use two ring gauges corresponding to the two limit sizes of tolerance class H7 to check [see 7.3a)] and use a pair of ring gauges. Should be checked on the ring gauge [see 7.3b)] of tolerance class H7 tolerance average value, there is a tolerance difference between the two. In addition, gauge inspection There are also tolerance differences between the size and the size measured with a measuring instrument. Therefore, the inspection rules should be subject to the agreement reached between the supply and demand parties.

8 Assembly

Cylindrical bushings or flange bushings should be assembled into the bearing housing with the help of auxiliary stepped spindles. The mandrel is preferably made of surface-hardened mild steel manufacture. The bearing seat hole should be machined with 45° bearing bush lead-in chamfer to facilitate assembly. For flange bushings, the minimum chamfer should be rmax×45° (to take into account the method The fillet radius after the blue). The shaft sleeve, mandrel and bearing seat should be correctly aligned during assembly. The recommended mandrel and chamfer dimensions are shown in Figure 3. ......

Image     

Tips & Frequently Asked Questions:

Question 1: How long will the true-PDF of GB/T 39743-2021_English be delivered?

Answer: Upon your order, we will start to translate GB/T 39743-2021_English as soon as possible, and keep you informed of the progress. The lead time is typically 1 ~ 3 working days. The lengthier the document the longer the lead time.

Question 2: Can I share the purchased PDF of GB/T 39743-2021_English with my colleagues?

Answer: Yes. The purchased PDF of GB/T 39743-2021_English will be deemed to be sold to your employer/organization who actually pays for it, including your colleagues and your employer's intranet.

Question 3: Does the price include tax/VAT?

Answer: Yes. Our tax invoice, downloaded/delivered in 9 seconds, includes all tax/VAT and complies with 100+ countries' tax regulations (tax exempted in 100+ countries) -- See Avoidance of Double Taxation Agreements (DTAs): List of DTAs signed between Singapore and 100+ countries

Question 4: Do you accept my currency other than USD?

Answer: Yes. If you need your currency to be printed on the invoice, please write an email to Sales@ChineseStandard.net. In 2 working-hours, we will create a special link for you to pay in any currencies. Otherwise, follow the normal steps: Add to Cart -- Checkout -- Select your currency to pay.