Friction wedge design optimized for high warp friction moment and low damping force

摘要

A damping system for a rail car truck utilizes friction wedges supported on side springs to damp relative movement between the rail car truck bolster and the side frames supporting it. Each friction wedge has a generally triangular shape with an angle &thgr; defined between a vertical friction surface which bears against a side frame and a sloping friction surface which moves relative to the bolster. The angle &thgr; and the force P of each side spring are defined by $\mathop{\mathrm{image}}$ {\mathrm{Fw}}_{W.E}=\frac{-P}{2}\·\frac{\left(\cos \⁢\text{\ }\⁢\left(\mathrm{\θ}\right)+\⁣{\mathrm{\μ}}_{2\⁢w}\·\sin \⁡\left(\mathrm{\θ}\right)\right)}{\left({\mathrm{\μ}}_{1\⁢w}\·\cos \⁢\text{\ }\⁢\left(\mathrm{\θ}\right)+{\mathrm{\μ}}_{1\⁢w}\·{\mathrm{\μ}}_{2\⁢w}\·\sin \⁡\left(\mathrm{\θ}\right)+{\mathrm{\μ}}_{2\⁢w}\·\cos \⁢\text{\ }\⁢\left(\mathrm{\θ}\right)-\sin \⁡\left(\mathrm{\θ}\right)\right)}\·\frac{2\⁣\·a\·w_w}{\left[b\·\left(a\·w_w\right)\right]}$$ V_{c.W.E}=2\·{\mathrm{\μ}}_{1\⁢d}\·P\·\frac{\left(\cos \⁢\text{\ }\⁢\left(\mathrm{\θ}\right)-{\mathrm{\μ}}_{2\⁢d}\·\sin \⁡\left(\mathrm{\θ}\right)\right)}{\left(-{\mathrm{\μ}}_{1\⁢d}\·\cos \⁡\left(\mathrm{\θ}\right)+{\mathrm{\μ}}_{1\⁢d}\·{\mathrm{\μ}}_{2\⁢d}\·\sin \⁡\left(\mathrm{\θ}\right)+{\mathrm{\μ}}_{2\⁢d}\·\cos \⁡\left(\mathrm{\θ}\right)+\sin \⁡\left(\mathrm{\θ}\right)\right)}$$