To improve a work environment while restraining a temperature rise in an upper end part of a connection rod being a cooling object, by restraining groaning sound from the inside of a peripheral wall member 18.SOLUTION: A first blower fan 68 for blowing air toward the upper end part side of a connection rod 58 is provided in a front side part of a peripheral wall member 18 via an annular spacer 70, and a second blower fan 78 for blowing air toward the upper end part side of the connection rod 58 is provided in a rear side part of the peripheral wall member 18 via an annular spacer 80. The rotation axis 68s of the first blower fan 68 and the rotation axis 78s of the second blower fan 78 are not concentrically matched. The rotation axis 68s of the first blower fan 68 and the rotation axis 78s of the second blower fan 78 are respectively inclined to one side around an upper end part of the connection rod 58 to the Y axis direction being the opposite direction of the first blower fan 68 and the second blower fan 78.SELECTED DRAWING: Figure 2
展开▼
