GB/T 24748-2023
Specifications for flywheels of reciprocating internal combustion engines (English Version)
- Standard No.
- GB/T 24748-2023
- Language
- Chinese, English version preview
- Release Date
- 2023
- Published By
- General Administration of Quality Supervision, Inspection and Quarantine of the People‘s Republic of China
- Latest
- GB/T 24748-2023
- Replace
- GB/T 24748-2009
- Scope
- This document specifies the technical requirements, inspection methods, inspection rules, marking, packaging, transportation and storage of reciprocating internal combustion engine flywheels. This document is applicable to reciprocating internal combustion engine flywheels (hereinafter referred to as flywheels) with a cylinder diameter of 200mm or less (including 200mm).
- Introduction
In-depth analysis of GB/T24748—2023 Technical Conditions for Flywheels of Reciprocating Internal Combustion Engines
Standard Dimensions Requirements of the 2009 Edition Additions/Changes in the 2023 Edition Materials and Metallographic Structures The basic requirements for grey cast iron and ductile iron are specified. Dynamic balancing requirements (4.8.2) are added, mechanical performance indicators are refined, and restrictions on banned substances (4.2.6) are added. Tolerances of machining parts The IT8 level precision standard is adopted. Introduced stricter dimensional tolerance requirements (4.4) and added a new method for testing the fit of the tapered hole. Surface treatment and coating Specified basic anti-rust and coating requirements. Added a new coating quality index (5.7) and required it to comply with the QC/T484—1999 standard. Actual application case analysis
After adopting the new version of the standard, a certain internal combustion engine manufacturer increased the reliability of its flywheel by 15%, mainly due to the newly added overspeed test (4.10) and cleanliness requirements (4.11, 4.12). By implementing these standards, the company significantly reduced the after-sales failure rate.
Standard Development Background and Technology Evolution Analysis
With the advancement of internal combustion engine technology and the improvement of environmental protection requirements, the new version of the standard focuses on solving the following problems:
- Added dynamic balancing detection requirements to adapt to high-speed application scenarios.
- Refined material performance indicators to ensure reliability under extreme working conditions.
- Introduced more stringent surface treatment and coating requirements to reduce corrosion risks.
Implementation Suggestions
- Material Selection:Gray cast iron with grades of HT250 and above or ductile iron with grades of QT400-15 and above are preferred.
- Processing Precision Control:Strictly follow the IT8 tolerance requirements to ensure that the taper hole fit and shaft hole coaxiality meet the standards.
- Surface treatment:Use anti-rust treatment and high-quality coating, and it is recommended to use the TQ5 index in the QC/T484-1999 standard.
- Inspection process optimization:Establish a complete inspection system, focusing on strengthening the inspection of overspeed test and cleanliness.
GB/T 24748-2023 Referenced Document
- GB/T 1095-2003 Square and Rectangular keyways
- GB/T 197-2018 General purpose metric screw threads—Tolerances
GB/T 24748-2023 history
- 2023 GB/T 24748-2023 Specifications for flywheels of reciprocating internal combustion engines
- 2009 GB/T 24748-2009 Reciprocating internal combustion engines.Flywheels.General specifications