Bearing housing. The DTII type idler is a stamped bearing seat idler. It has been proved by experience that the bearing seat punched with 3mm thick steel plate is strong and easy to ensure the assembly precision and running flexibility of the roller. The accuracy of the bearing housing will also directly affect the quality of the roller. In order to ensure the inner hole size after punching and the coaxial between the inner hole and the outer diameter, we selected the high-quality plate and mold material design tool and used the CO2 gas protection automatic welding machine to weld the bearing seat to the pipe with the bearing part as the reference. In fact, this not only ensures the three-level precision requirement of the inner hole, but also makes the rotation resistance of the roller and the radial circular runout not exceed the difference, and greatly reduces the overall weight of the roller.