the bearing surface 51 is nominally the same size as that of the roller shaft typically the roller shaft will be 1 u00bc u2033 or metric equivalent in diameter but may be somewhat smaller or larger as required the length of the bearing 31 measured in the direction parallel to the axis of the surface 51 is typically about 1 7 16 u2033 or metric equivalent but can be somewhat smaller or larger as desired at the ends of the arcuate span of the bearing 31 are generally radial faces 53 adjacent the inner bearing surface 51 these faces are preferably truly or nearly radial so that they are inclined from the horizontal at an angle of about 30 degrees this inclination of these areas 54 serves to shed dust and other debris that may be generated during operation of the dryer and rotation of the rollers 11 so as to carry such dirt and debris away from the interface of the bearing surface 51 and surface of the roller shaft 12 under the influence of gravity and any vibratory forces as well as a wiping action on the leading side of the rotating roller shaft because the bearing 31 subtends an arc substantially less than 180 degrees the roller shaft 12 overlies the exposed arcuate ends of the interface of its surface and the bearing surface 51 thereby tending to shield this area from falling dirt and debris the radial faces 53 are additionally characterized by the presence of axial slots or grooves 56 outward of the radial areas.