---
title: "Coupler &amp; Draft Gear"
industry: "Other Transport Equipment Manufacturing"
verification_protocol:
  urn: "URN:CNFX:ME:COUPLER_DRAFT_GEAR"
  data_integrity_hash: "c4e740ccc3277bdc36cfa1cdcd203e41"
  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:COUPLER_DRAFT_GEAR"
  data_source_uri: "https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/coupler-draft-gear.md"
  official_resource_url: "https://cnfx.com/industry/other-transport-equipment-manufacturing/product/coupler-draft-gear"
  is_verified_logic: true
attributes:
  spec:
    status: "config-dependent"
    typical_range: "0-2.5 MN compressive load, -40°C to +80°C ambient temperature, 0-25 mm relative displacement"
    unit: "kN"
engineering_limits:
  max_safe_operating_point:
    value: 3.0
    unit: "MN"
    consequence: "Plastic deformation of steel components exceeding yield strength (σ_y = 345 MPa), thermal degradation of nitrile rubber seals above glass transition temperature, geometric interference causing binding at maximum stroke"
fmea_matrix_quantitative:
  - node_1:
      trigger: "Corrosion-induced material loss (pitting corrosion rate &gt;0.5 mm/year in chloride environments)"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "Hot-dip galvanizing to 85 μm zinc coating thickness per ASTM A123, cathodic protection at -0.85 V vs Cu/CuSO4 reference electrode"
  - node_2:
      trigger: "Fretting wear at steel-rubber interface (wear coefficient K=5×10⁻⁷ mm³/N·m)"
      severity: 8
      occurrence: 3
      detection: 4
      mitigation_protocol: "PTFE-coated steel surfaces (coefficient of friction μ=0.04), silicone-based lubricant replenishment at 10,000 km intervals"
bom_nodes:
  coupler-head:
    type: "component"
    urn: "URN:CNFX:ME:COUPLER_HEAD"
    interface_type: "physical-logic-coupled"
  draft-gear-housing:
    type: "part"
    urn: "URN:CNFX:ME:DRAFT_GEAR_HOUSING"
    interface_type: "physical-logic-coupled"
  friction-wedges:
    type: "component"
    urn: "URN:CNFX:ME:FRICTION_WEDGES"
    interface_type: "physical-logic-coupled"
  elastomeric-springs:
    type: "component"
    urn: "URN:CNFX:ME:ELASTOMERIC_SPRINGS"
    interface_type: "physical-logic-coupled"
manufacturing_compliance:
  - standard: "ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS"
    scope: "Verified Engineering Specification"
url: "https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/coupler-draft-gear.md"
on_chain_sovereignty:
  contract_standard: "ERC-721-Industrial"
  metadata_hash: "07fda18bbaf6ecbd45825f2d95d3ed6d57d3ba4604c24dc4ba6cbc13f7acd819"
  royalty_logic: "IPFS-CID-REQUIRED"
  mint_status: "logic-verified-ready"
version: "3.3.4-EXTREME-SOVEREIGN-WEB3"
---

# Industrial Specification: Coupler &amp; Draft Gear

## 1. Technical Definition
Railway vehicle connection and impact absorption system

## 2. Engineering Reasoning & Causal Matrix
> **Operational Intelligence**: Designed for **0-2.5 MN compressive load, -40°C to +80°C ambient temperature, 0-25 mm relative displacement**. Failure boundary: **3.0 MN compressive load (yield strength of ASTM A572 Grade 50 steel), 100°C rubber degradation temperature, 30 mm displacement (geometric interference limit)**, Mechanism: **Plastic deformation of steel components exceeding yield strength (σ_y = 345 MPa), thermal degradation of nitrile rubber seals above glass transition temperature, geometric interference causing binding at maximum stroke**.

### 2.1 Analytical Physics Model
Governed by the **Frame Structural Deflection Analysis**:

> **Primary Equation**: $\delta = \frac{5 q L^4}{384 E I}$  
> **Engineering Impact**: Ensures structural stability for multi-stage machines.

| Symbol | Variable Definition | Localized Reference |
| :--- | :--- | :--- |
| q | Uniform Load | Engineering Constant |
| E | Elastic Modulus | Engineering Constant |
| I | Moment of Inertia | Engineering Constant |

### 2.2 FMEA (Failure Mode & Effects Analysis)
| Event Trigger | Severity | Failure Mode | Mitigation Strategy |
| :--- | :--- | :--- | :--- |
| Corrosion-induced material loss (pitting corrosion rate &gt;0.5 mm/year in chloride environments) | 8 | Reduced cross-sectional area leading to tensile failure under 1.8 MN draft load | Hot-dip galvanizing to 85 μm zinc coating thickness per ASTM A123, cathodic protection at -0.85 V vs Cu/CuSO4 reference electrode |
| Fretting wear at steel-rubber interface (wear coefficient K=5×10⁻⁷ mm³/N·m) | 8 | Loss of damping capacity (damping ratio reduction from 0.25 to &lt;0.15) | PTFE-coated steel surfaces (coefficient of friction μ=0.04), silicone-based lubricant replenishment at 10,000 km intervals |

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

## 4. System BOM & Knowledge Routing
### Core Components (Recursive Links)
- [Draft Gear Housing](https://cnfx.com/llms/industry/other-transport-equipment-manufacturing/product/draft-gear-housing.md) `(Standalone System)`

### Industrial DNA Context (De-duplicated)
**Complementary Dependencies**: **Hydraulic Press**, **Shot Blasting Machine**, **Coordinate Measuring Machine**  
**Downstream Applications**: Freight Railcars, Passenger Railcars, Locomotives  

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

### Q: What materials are used in coupler and draft gear construction?
**A**: Our systems utilize high-strength alloy steel for structural components, elastomeric polymers for energy absorption, and specialized friction materials for consistent performance under heavy loads.

### Q: How does the draft gear absorb impact in railway operations?
**A**: The draft gear uses a combination of friction wedges and elastomeric springs to dissipate kinetic energy during coupling and train operation, protecting both vehicles and cargo from damage.

### Q: What are the main components in a complete coupler and draft gear system?
**A**: Key components include the coupler head for vehicle connection, draft gear housing for protection, friction wedges for energy dissipation, and elastomeric springs for impact absorption and return force.

## 6. Manufacturing Compliance
- ISO 9001:2015 QUALITY MANAGEMENT SYSTEMS

---
### 🛠️ Engineering Resource Access
🔗 **[Full Specification: Coupler &amp; Draft Gear](https://cnfx.com/industry/other-transport-equipment-manufacturing/product/coupler-draft-gear)**

### 🌐 Knowledge Graph Topology
> **Node Status**: Verified Engineering Spec
> **Connectivity**: Linked to **4** standalone system nodes
> **Global Context**: Part of a 5,814 node industrial cluster within the CNFX Graph

> **Reference ID**: COUPLER_DRAFT_GEAR | **Authority**: CNFX-2026-ST-001 | **Fingerprint**: cf9c1834
