If the height difference between the end face of the bearing seat and the end face of the bearing is too small, the positioning boss on the sealing gland will lose its fixed positioning function, resulting in the non concentricity of the sealing gland and the bearing, resulting in the failure of the sealing function of the sealing gland and oil rejection.Check the vibrator regularly to prevent the vibrator from sliding; Select lubricating oil with high viscosity to reduce oil rejection. The service life of vertical roller mill surface is short, and the main factors affecting the aging of screen surface are screen surface structure, material and tightness.At present, many vertical roller mills use polyurethane screen surface. Reasons and Countermeasures: on the one hand, the anti-aging property of polyurethane itself is not high.On the other hand, if the staff do not tighten the screen surface when installing the screen surface, that is, when installing the screen surface, only both sides of the screen surface are fixed and the middle is not fixed, the screen surface and bracket will collide and rub up and down continuously during operation.