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GB/T 23921-2023 PDF in English


GB/T 23921-2023 (GB/T23921-2023, GBT 23921-2023, GBT23921-2023)
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GB/T 23921-2023English200 Add to Cart 0-9 seconds. Auto-delivery. Tri-wheel vehicles -- Axle shaft Valid

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GB/T 23921-2023: PDF in English (GBT 23921-2023)

GB/T 23921-2023
GB
NATIONAL STANDARD OF THE
PEOPLE'S REPUBLIC OF CHINA
ICS 65.060
CCS T 54
Replacing GB/T 23921-2009
Tri-wheel vehicles - Axle shaft
ISSUED ON: NOVEMBER 27, 2023
IMPLEMENTED ON: JUNE 1, 2024
Issued by: State Administration for Market Regulation;
Standardization Administration of PRC.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Terms and definitions ... 5
4 Technical requirements ... 6
5 Test methods ... 8
6 Inspection rules ... 11
7 Marking, packaging, transportation, and storage ... 13
Tri-wheel vehicles - Axle shaft
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.
3.1 axle shaft
The axle that transmits the torque transmitted from the differential or final drive to the
wheels of a tri-wheel vehicle.
NOTE: Some axle shafts can withstand bending moments.
3.2 full-floating axle shaft
An axle shaft that transmits only torque.
3.3 semi-floating axle shaft
An axle shaft that both transmits torque and withstands bending moments.
3.4 rated torque
Maximum allowable torque designed for an axle shaft.
3.5 ultimate failure torque of static torsional testing
The maximum breaking torque value during the static torsion testing of an axle shaft.
3.6 static torsional strength safety factor
The ratio of the ultimate failure torque of static torsional testing of an axle shaft to the
rated torque of the axle shaft.
3.7 torsional fatigue life
The number of cycles at which cracks or fractures occur during axle shaft torsional
fatigue testing.
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
6.1 Factory inspection
6.1.1 Each axle shaft shall be inspected by the manufacturer before it can leave the
factory. The product shall be accompanied by a certificate of conformity when it leaves
the factory.
6.1.2 See Table 1 for factory inspection items and the classification of non-conformance.
The manufacturer shall follow the inspection sampling and judgment rules specified in
GB/T 2828.1. For spline form and position tolerances, material requirements, roughness,
internal defects, and surface quality, the manufacturer shall sample and inspect whether
the axle shaft complies with the provisions of Chapter 4. It is recommended to use
normal inspection with a single sampling plan, the inspection batch size is the daily (or
hourly) output of the product or the quantity of each packaging batch, the inspection
level is general inspection level-II, and the acceptance quality limit (AQL) is 4.0.
6.2 Type inspection
6.2.1 Type inspection shall be carried out whenever one of the following situations
occurs:
a) Pattern evaluation of trial production of new products or old products
transferred to another factory for production;
b) During formal production, when there are major changes in structure,
materials, and processes, which may have effects on product performance;
c) When production is resumed after a long time (more than half a year) of
suspension;
d) When mass-produced products are inspected periodically (at least once every
six months);
e) When the factory inspection results are significantly different from the last
type inspection;
f) When the national quality supervision organization requests type inspection.
6.2.2 The inspection items and the classification of non-conformance of type inspection
are shown in Table 1.
6.2.3 The inspection items that do not meet the requirements of Chapter 4 are
nonconforming items (defects) and are divided into Category A nonconforming items
and Category B nonconforming items according to their importance on the quality
6.2.5 The judgment rules for type inspection are as follows.
-- In each nonconforming category, when the number of nonconforming samples
is not greater than Ac, the category is evaluated as qualified, and when the
number of nonconforming samples is not less than Re, the category is evaluated
as unqualified. When all nonconforming categories are qualified, the final
assessment is qualified; when one or more nonconforming categories are
evaluated as unqualified, the final assessment is unqualified.
-- If a failure occurs due to product quality problems, the testing shall be stopped
and the product will be treated as unqualified.
6.3 Inspection under special circumstances
For other forms of inspection, the sampling quantity and judgment rules can be
determined according to the corresponding requirements, and the test results shall
comply with the provisions of this document.
7 Marking, packaging, transportation, and storage
7.1 Marking
The outer end of an axle shaft flange shall be marked with the manufacturer's mark.
7.2 Packaging
7.2.1 Axle shafts shall be packaged with anti-rust and anti-collision packaging methods.
7.2.2 The following documents shall be attached when axle shafts are packed:
a) Product certificate;
b) User feedback form;
c) Packing list.
7.2.3 The pictorial mark on the outside of the packaging box shall comply with the
provisions of GB/T 191, and shall indicate the following:
a) Manufacturer's name and address;
b) Product name and specifications;
c) Implementation standard number;
d) Mass (net weight and gross weight including packaging), in kilograms (kg);
......
 
Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.