| SI.Length | one_meter | 1 | |
| Geometric data |
| SI.Diameter | d | | Nominal diameter of spindle |
| SI.Length | P | | Pitch of spindle |
| SI.Length | l_S | 1 | Length of spindle |
| SI.Conversions.NonSIunits.Angle_deg | rho | 0.2 | Angle of friction |
| Calculated › Geometric data |
| SI.Length | l_S_u | 0.9*l_S | Unsupported length of spindle |
| SI.Conversions.NonSIunits.Angle_deg | phi | SI.Conversions.to_deg(atan(P/(Constants.pi*d))) | Angle of lead |
| Physical data |
| SI.Density | density | 7900 | Density of spindle material |
| SI.TranslationalSpringConstant | R_nu | 0.5*10^9 | Nut rigidity on nut flange |
| SI.TranslationalSpringConstant | R_S | 0.09*10^9 | Spindle rod rigidity per m |
| Real | mu | 0.006 | Friction coefficient of bearing |
| Calculated › Physical data |
| Modelica.SIunits.Mass | m | (d/2)^2*Constants.pi*l_S*density | Mass of Spindle |
| Real | eta | tan(SI.Conversions.from_deg(phi))/tan(SI.Conversions.from_deg(phi + rho)) | Value of efficiency of nut |
| SI.MomentOfInertia | J | 0.5*m*d^2/4 | Moment of inertia of the spindle |
| SI.TranslationalSpringConstant | R_ax | 1/(1/R_nu + l_S_u/one_meter/(R_S*k)) | Axial rigidity |
| Engineering data |
| SI.Force | C_am | 50000 | Dynamic load rating of nut |
| SI.Force | C_0am | 80000 | Static load rating of nut |
| Real | preload_factor | 0.07 | Preload of factor for nut. preload_factor = F_pr/C_am |
| SI.Force | F_pr_Bearing | 0 | Preload force of bearing |
| BearingConfiguration | bearingConfiguration | BearingConfiguration.fixed_supported | Bearing method of spindle |
| SI.Mass | m_ref | 1000 | Reference mass for eigenfrequency |
| Calculated › Engineering data |
| SI.Diameter | d_B | 1.6*d | Diameter of bearing |
| SI.Force | F_pr | preload_factor*C_am | Preload force of nut |
| SI.Frequency | f_bs | 1/(2*Constants.pi)*sqrt(R_ax/m_ref) | Eigenfrequncy of ball screw |
| SI.Conversions.NonSIunits.AngularVelocity_rpm | n_krit | k_L*d/l_S_u^2 | critcial rotational speed of spindle |
| SI.Force | F_b | k_buckling*d^4/l_S_u^2 | Buckling force |
| Limiting data |
| SI.Frequency | f_min | 50 | Minimum eigenfrequncy of ball screw and spindle. Constraint f_bs > f_min |
| SI.Conversions.NonSIunits.Time_hour | L_h_min | 10000 | Minimum life expectancy of nut |
| Real | DN_perm | 160000 | Permissible DN value of nut (diamater*max_speed) |
| Safety factors |
| Real | S_n_krit | 1.25 | Safety factor for n_krit |
| Real | S_F_b | 2 | Safety factor for buckling |
| Real | S_C_0am | 3 | Safety factor for static load rate |