GB/T 23921-2023Tri-wheel vehicles—Axle shaft (English PDF)

1 Scope

This document specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation, and storage of tri-wheel vehicle axle shafts (hereinafter referred to as axle shafts).

This document is applicable to the design, manufacture, and product quality inspection of axle shafts for tri-wheel vehicles.

2 Normative references

The following documents contain the provisions which, through normative reference in this document, constitute the essential provisions of this document. For the dated referenced documents, only the versions with the indicated dates are applicable to this document; for the undated referenced documents, only the latest version (including all the amendments) is applicable to this document.

GB/T 191 Packaging - Pictorial marking for handling of goods

GB/T 2828.1 Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection

GB/T 3077 Alloy structure steels

GB/T 5216 Structural steel with specified hardenability bands

GB/T 5617 Determination of effective depth of hardening after induction or flame hardening of steel

GB/T 10610 Geometrical product specifications(GPS) - Surface texture: Profile method - Rules and procedures for the assessment of surface texture

3 Terms and definitions

The following terms and definitions apply to this document.

4 Technical requirements

4.1 Axle shafts shall be manufactured in accordance with product drawings and technical documents.

4.2 Under the condition of ensuring product design performance requirements, axle shaft material shall comply with the chemical composition, mechanical properties, and other relevant requirements required by GB/T 3077 and GB/T 5216. The recommended materials for axle shafts are 40Cr, 40CrH, 42CrMo, 42CrMoH, 40MnB, 40MnBH, and 50CrVA. Other materials that meet the requirements of this document can also be used.

4.3 It is recommended to use the surface medium frequency quenching process after pre-tempering treatment. Under the condition of ensuring the performance index requirements of the axle shaft, other heat treatment processes can be used, such as the surface medium frequency quenching process after normalizing treatment.

4.4 After heat treatment of the axle shaft, the surface hardness and hardened layer depth shall meet the following requirements:

-- The recommended core hardness value of the axle shaft after pre-tempering treatment is 24 HRC~30 HRC, and the recommended core hardness value of the axle shaft made of 42CrMo and 42CrMoH materials after pre-tempering treatment is 28 HRC~36 HRC;

-- The surface hardness of the rod after medium frequency quenching treatment is not less than 52 HRC, and the spline can be reduced by 3 HRC; the depth of the hardened layer of the rod ranges from 10% to 20% of the diameter of the rod, and the change in the depth of the hardened layer is not greater than 5% of the diameter of the rod;

-- The effective depth of the quenched and hardened layer at the spline is measured from the minor diameter of the spline, and its depth is not less than 10% of the major diameter of the spline; the length of the non-quenching area of the spline is measured from the end of the spline, and the maximum value is 10 mm;

-- The effective depth of the hardened layer at the root fillet of the axle shaft flange is measured along the direction of the fillet, the depth of the hardened layer is not less than 5% of the root diameter of the axle shaft flange and is not greater than the upper limit value of the effective depth of the quenched and hardened layer at the rod; the hardness of the semi-floating axle shaft flange shall be 180 HB~240 HB.

4.5 Roughness shall meet the following requirements:

-- For the installation end face of the flange, it shall not be larger than Ra3.2;

-- The surfaces of the non-processed rod and the fillet at the rod root are rough surfaces. For the processed rod, it is not larger than Ra6.3 (if shot-peened surface, it is allowed to be not larger than Ra12.5), and for the fillet at the processed rod root, it is not larger than Ra3.2;

-- For the mating surface of the bearing and oil seal, it is not larger than Ra1.6;

-- For the spline outer circle centering surface, it is not larger than Ra1.6;

-- For the tooth side centering surface, it is not larger than Ra3.2.

4.6 There shall be no defects such as cracks inside the axle shaft.

4.7 The cumulative pitch tolerance, tooth profile tolerance, and tooth composite tolerance of the axle shaft spline teeth shall comply with the requirements of the product drawing.

4.8 There shall be no defects such as folds, dents, scratches, or cracks on the surface of the axle shaft. The surface of the rod may show signs of cleaning defects. The depth of […]

6 Inspection rules

7 Marking, packaging, transportation, and storage