Author: Site Editor Publish Time: 2025-09-18 Origin: Site
I. Importance of the Wheelset
The wheelset is a critical component of the bogie. Its functions include supporting the entire weight of the vehicle body, ensuring high-speed operation on rails, and withstanding multi-directional static and dynamic loads from both the vehicle body and the tracks. Given its extremely complex stress state, the wheelset must possess exceptionally high structural strength and durability, with all dimensions strictly complying with technical standards.
II. Definitions of Assembly Types
Wheelset assembly is categorized into the following two types:
1.New Wheelset Assembly: Refers to the assembly process using newly manufactured wheels and axles, conducted entirely in accordance with new (prototype) technical standards.
2.Wheelset Re-assembly: Refers to assembly performed according to workshop repair technical standards. It is further subdivided based on component replacement:
· Reassembly with Used Parts: Utilizes a used axle and used wheels.
· Axle Replacement: Utilizes a new axle and used wheels.
· Wheel Replacement: Utilizes a used axle and new wheels.
III. Assembly Process Flow
The wheelset assembly must follow a stringent process. The key difference between re-assembly and new assembly is that the former requires an additional "Wheel Tread Machining" step when used wheels are involved, ensuring the tread profile and dimensions meet operational standards.
| No. | Process Step | New Assembly | Re-assembly |
| 1 | Axle & Wheel Selection & Matching | ✓ | ✓ |
| 2 | Wheelset Pressing | ✓ | ✓ |
| 3 | Ultrasonic Inspection of Wheel Seat | ✓ | ✓ |
| 4 | Wheel Tread Machining | ✓ | |
| 5 | Wheelset Dimensional Inspection | ✓ | ✓ |
| 6 | Axle End Marking Engraving | ✓ | ✓ |
| 7 | Wheelset Painting & Protection | ✓ | ✓ |
| 8 | Wheelset Inspection & Acceptance | ✓ | ✓ |
IV. Key Technical and Quality Requirements
1.Matching Rules: Wheels of the identical model and material must be assembled on the same axle. The wheelset model is defined by the axle model.
2.Rim Width Tolerance: The difference in rim width between the two wheels on the same axle must be strictly controlled: ≤5 mm for cast steel wheels; ≤3 mm for wrought steel wheels.
3.Prohibition Clause: If an assembled wheelset fails to meet acceptance criteria, it is strictly prohibited to reassemble the original wheel and the original axle together again after disassembly. The components must be inspected, and the root cause of the failure must be identified and addressed.
