1 Introduction
2 Configuration of the Support Hydraulic System
3 Dynamic Model of Support Hydraulic System
3.1 Dynamic Model of Gripper Cylinder
3.2 Dynamic Model of Relief Valve
3.2.1 Flow Equation for Relief Valve
3.2.2 Mechanical Analysis of Relief Valve Core
3.3 Dynamic Model of Support Hydraulic System
4 Nonlinear Stiffness Characteristics Analysis
Quantity | Symbol | Value | Units |
---|---|---|---|
Area of rod chamber | \( A_{c} \) | 0.411 | m2 |
Damping coefficient | \( B_{v} \) | 200 | N·s/m |
Piston diameter | \( d \) | 0.915 | m |
Seat diameter | \( D_{\text{s}} \) | 0.02 | m |
Friction force of cylinder | \( F_{\text{fc}} \) | 500 | N |
Spring stiffness | \( k \) | 15 | kN/m |
Piston length | \( l_{\text{c}} \) | 0.26 | m |
Cylinder body mass | \( m_{\text{c}} \) | 2000 | kg |
Valve mass | \( m_{\text{v}} \) | 0.5 | kg |
Supply pressure | \( p_{\text{s}} \) | 23 | MPa |
Kinematic viscosity | \( \upsilon \) | 20 | mm2/s |
Volume of rod chamber | \( V \) | 0.123 | m3 |
Spring pre-compression | \( y_{0} \) | 0.015 | m |
Fluid density | \( \rho \) | 870 | kg/m3 |
Absolute viscosity | \( \mu \) | 0.017 | Pa·s |
Clearance of | \( \delta_{1} \) | 0.01 | mm |
Half cone angle | \( \theta \) | 30 | (°) |
Bulk modulus | \( \beta_{\text{e}} \) | 1.7 | GPa |