| 摘要 |
PURPOSE:To enable a dust preventive function and a cooling function to exhibit with good efficiency by a method in which an air introduction duct having an air intake port facing the advancing direction is provided to the dust cover and a metal lath netting is integrally formed in the air intake port. CONSTITUTION:A notch 28 for avoiding caliper is formed on the back side of the advancing direction of a dust cover 22, and an air introduction duct 30 is provided on the opposite side of the notch 28 across a hole 24 for inserting the shaft, or on the front side of the advancing direction. An air intake face 32 is formed on the periphery facing the advancing direction of the duct 30, where a metal lath netting 34 is formed. |
