GB/T 6577-2021Types, dimensions and tolerances of groove for seals with bearing rings for hydraulic cylinders piston (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for Standardization Work Part 1: Structure and Drafting Rules of Standardization Documents" Drafting.

This document replaces GB/T 6577-1986 "Type, Dimensions and Tolerances of Seal Groove with Support Ring for Piston of Hydraulic Cylinder", and Compared with GB/T 6577-1986, in addition to structural adjustments and editorial changes, the main technical changes are as follows.

a) Modified normative references (see Chapter 2, Chapter 2 of the 1986 edition);

b) In the symbol, d1, d2, and d3 are respectively modified to d, d1, and d2, the symbols L3 and S are deleted, and the symbols r and r2 are added (see Chapter 4, 1986 Chapter 3 of the Year Edition);

c) Modified the roughness requirements of the groove diagram and the size of r2, and added the cross-sectional schematic diagram of the combined seal (see Figure 1 and Figure 2, (Figure from 1986 edition);

d) The assembly groove diagram has been added (see Figure 2);

e) The tolerance of L1, the size of C, and the size of r1 in Table 1 have been revised, and the note "(2)" in the table has been deleted (see Table 1, the 1986 edition of the table);

f) Part of the groove size series has been added (see Table 1, the 1986 edition of the table).

1 Scope

This document specifies the symbols, types, dimensions and tolerances of the combined sealing grooves with supporting rings for hydraulic cylinder pistons.

This document is applicable to the belt supporting ring which is installed on the piston of the reciprocating hydraulic cylinder with the cylinder diameter of 20mm~500mm to play a two-way sealing function. Combined seal (hereinafter referred to as combined seal).

2 Normative references

The contents of the following documents constitute the indispensable clauses of this document through normative references in the text. Among them, dated quotations Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to this document.

GB/T 1031 Product Geometric Technical Specification (GPS) Surface Texture Profile Method Surface Roughness Parameters and Numerical Values

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Symbols

The following symbols apply to this document.

C --- the axial length of the chamfer;

D ---Outer diameter of combined sealing groove (bore diameter);

d ---The inner diameter of the combined sealing groove (the bottom diameter of the piston sealing groove);

d1 --- The diameter of the part where the piston fits with the support ring;

d2 --- Piston diameter;

L1 --- Axial length of combined sealing groove;

L2 --- The axial length of the part on the piston that matches the support ring;

r, r1, r2 --- fillet radius.

5 Groove type

There are two types of grooves for combined sealing. integral type and assembly type, as shown in Figure 1 and Figure 2. The surface roughness Ra of the groove should meet According to GB/T 1031, there should be no burrs, sharp corners and rough machining marks at the installation chamfers.