---
title: "Wheelset"
industry: "Other Transport Equipment Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:WHEELSET"
  data_integrity_hash: "459689b0805c492df9d0f6f7a2eb9d21"
  source_authority: "https://cnfx.com"
  strict_mode: true
source_identity:
  provider: "CNFX Industrial Knowledge Graph"
  index_version: "2026.Q1-Universal"
  authority_id: "URN:CNFX:ME:WHEELSET"
  data_source_uri: "https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/wheelset.md"
  official_resource_url: "https://cnfx.com/industry/other-transport-equipment-manufacturing/product/wheelset"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-120 kN vertical load, 0-50 kN lateral load, 0-25 kN longitudinal load, -40°C to +80°C temperature"
    unit: "mm"
engineering_limits:
  max_safe_operating_point:
    value: 22
    unit: "mm"
    consequence: "Hertzian contact stress exceeding 1500 MPa causes subsurface fatigue cracks; thermal stresses from braking exceeding 400°C create martensitic white etching layers; residual stresses from press-fitting exceeding yield strength initiate brittle fracture"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Wheel-rail contact stress concentration at 1.5 GPa due to track irregularities"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Optimized wheel profile with 1:20 conicity, controlled plastic deformation through 0.2% yield strength management"
  - node_2:
      trigger: "Thermal gradient of 300°C/mm during emergency braking"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Composite brake block design limiting temperature rise to 350°C, wheel material with 0.6% carbon equivalent"
bom_nodes:
  axle:
    type: "component"
    urn: "URN:CNFX:ME:AXLE"
    interface_type: "physical-logic-coupled"
  wheel-x2:
    type: "component"
    urn: "URN:CNFX:ME:WHEEL_X2"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
url: "https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/wheelset.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "81fbb5485313fb9da0c307afe8c7c6889f11c1901c383ab3d5b8745eb5e5a121"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Wheelset

## 1. Technical Definition
A rotating assembly consisting of two wheels fixed to an axle, forming the rolling interface between a rail vehicle and the track.

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-120 kN vertical load, 0-50 kN lateral load, 0-25 kN longitudinal load, -40°C to +80°C temperature**. Failure boundary: **Wheel flange thickness &lt; 22 mm, wheel diameter &lt; 840 mm, axle bending stress &gt; 250 MPa, wheel tread hardness &lt; 280 HB**, Mechanism: **Hertzian contact stress exceeding 1500 MPa causes subsurface fatigue cracks; thermal stresses from braking exceeding 400°C create martensitic white etching layers; residual stresses from press-fitting exceeding yield strength initiate brittle fracture**.

### 2.1 Analytical Physics Model
Governed by the **L10 Bearing Life & Fatigue Model**:

> **Primary Equation**: $L_{10} = (\frac{C}{P})^p$  
> **Engineering Impact**: Predicts mechanical lifecycle before component fatigue.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| C | Dynamic Load Rating | Engineering Constant |
| P | Equivalent Dynamic Load | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Wheel-rail contact stress concentration at 1.5 GPa due to track irregularities | 8 | Subsurface rolling contact fatigue initiating at 3-5 mm depth, propagating as head checks and squats | Optimized wheel profile with 1:20 conicity, controlled plastic deformation through 0.2% yield strength management |
| Thermal gradient of 300°C/mm during emergency braking | 8 | Martensite formation in wheel tread creating 800 HV white etching layers leading to shelling | Composite brake block design limiting temperature rise to 350°C, wheel material with 0.6% carbon equivalent |

## 3. Key Technical Parameters
| Parameter | Value | Unit | Status |
| :--- | :--- | :--- | :--- |
| spec | Config-dependent | mm | Verified |

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Wheel Lathe**, **Axle Press**, **Dynamic Balancing Machine**  
**Downstream Applications**: Railway Freight Cars, Passenger Rail Coaches, Locomotive Bogies  

## 5. Engineering Risks & FAQ
- **Caution**: 
- **Caution**: 
- **Caution**: 

### Q: What are the main components of a rail wheelset?
**A**: A rail wheelset consists of three primary components: one solid axle and two wheels that are press-fitted onto the axle ends, creating a single rotating assembly.

### Q: Why is forged steel used for rail wheelsets?
**A**: Forged steel provides exceptional strength, durability, and fatigue resistance needed to withstand the heavy loads, high speeds, and constant stress of rail transport operations.

### Q: How often should rail wheelsets be inspected and maintained?
**A**: Rail wheelsets require regular inspection for wear, cracks, and defects. Maintenance intervals depend on usage, but typically include visual checks daily, detailed inspections monthly, and comprehensive overhauls annually or per mileage thresholds.

## 6. Manufacturing Compliance

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### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Wheelset](https://cnfx.com/industry/other-transport-equipment-manufacturing/product/wheelset)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **2** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: WHEELSET | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: 1670cb5b
