# Orbital-Based Automatic Multi-Layer Multi-Pass Welding Equipment for Small Assembly Plates
## 2 Design and Analysis of Rail-Mounted Automatic Welding Equipment
### Static Analysis of the Equipment's Core Mechanisms

Table 4: Statics analysis data. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Serial Number** & **Interaction Objects** & **Types of Mutual** & **Types of Interaction** \\ \hline
1 & Track roller and pedestal & Surface contact & Support bearing \\
2 & Wire feeder and track & Surface contact & Support bearing \\
3 & Track roller and single section track support bracket & Surface contact & Support bearing \\
4 & Track holder and track & Surface contact & Support bearing \\
5 & Track roller and single-edge guideway & Line contact & Meshing drive \\
6 & Adjustable setting handle and adjusting slide & Point contact & Fixed clamping \\
7 & Clamp and track & Surface contact & Fixed clamping \\
8 & Connecting flange and vertical plate & Surface contact & Fixed clamping \\
9 & Small assembly holder and small assembly & Surface contact & Fixed clamping \\
10 & Pedestal and robot arm connecting seat & Surface contact & Fixed clamping \\
11 & Robotic arm and robot arm connecting seat & Surface contact & Fixed clamping \\
12 & Guide bar and adjusting slide & Surface contact & Coupling locking \\
13 & Locking screw and welding gun holder & Point contact & Coupling locking \\
14 & Tapered positioning male and tapered positioning female & Surface contact & Coupling locking \\
15 & Notches and protruding platform & Surface contact & Coupling locking \\
16 & Laser sensor and laser sensor protective case & Surface contact & Coupling locking \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Detailed analysis of the interactivity of mechanical mechanisms and components. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Serial Number** & **Name of Organisation** & **Length/mm** & **Breadth/mm** & **Height/mm** & **Weight/kg** \\ \hline
1 & Railcat & 430 & 310 & 30 & 6.668 \\
2 & Track section & 500 & 256 & 72.7 & 4.1255 \\
3 & Robotic arm connecting seat & 140 & 140 & 150 & 1.3059 \\
4 & Fixing mechanism & 407 & 120 & 272 & 5.3895 \\
5 & Bias load simplification mechanism & 779 & 430 & 243 & 10.3635 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Mechanism dimension parameter. The analysis diagrams of the rail cart are illustrated in Figure 6. A pressure of 0.1876 MPa is applied to the surface of the rail cart, as shown in Figure 6a. The deformation of the rail cart is depicted in Figure 6b, where the maximum deformation of the model is 0.856 mm, occurring on the upper surface of the rail cart. The local and overall equivalent stresses are shown in Figures 6c and 6d, respectively. The maximum equivalent stress is 352.83 MPa, occurring on the rollers, reaching the yield strength of bearing steel GCr15, which is 353 MPa. In the simulation analysis for the application conditions or the actual engineering application of the mechanism, if the stress on the rollers approaches their maximum allowable range, the material can be replaced according to the corresponding performance requirements and safety demands, retaining a certain safety margin in the selection of material properties. According to safety regulations, it is necessary to prevent deformation and damage of the mechanism caused by overload on the surface of the rail car to avoid causing simultaneous damage to the equipment mounted on the rail car. Since the equipment is mounted on a track, the carrier vehicle must operate while maintaining the stability of the modules installed above the vehicle without interference. The following layout is therefore adopted: The mounting center of the robotic arm instal  
Figure 5: Rail cart grid division model diagram. (**a**) Finite element module division diagram. (**b**) Finite element mesh division diagram. Figure 6: Rail cart analysis diagram. lation base is aligned with the center of the upper surface of the track vehicle. The wire feeder mounting center is offset 66 mm along the \(Z\)-axis relative to the base, forming an asymmetric layout.