| 摘要 |
PURPOSE:To obtain high performance and low manufacturing cost by preventing working errors from accumulating, thereby making a gap between a pitch line of a passive rack and a crank shaft constant with high accuracy. CONSTITUTION:A machine disclosed in this invention is provided with a passive rack 21 having a plurality of teeth T1, active racks 12A to 12C, in which a plurality of teeth T2 whose pitches are the same as that of teeth T1 are formed and each tooth of which abuts on the passive rack 21, and crank shafts 15A, 15B, which support the active racks 12A to 12C by a prescribed phase difference and which give oscillating crank motion to the active racks 12A to 12C by the same phase difference. In addition, the machine is provided with a case for supporting the crank shafts 15A, 15B, a passage which is formed in the case and through which a plurality of balls are able to circulate, and a groove, which is formed in parallel with the pitch line of the passive rack 21 and which is engaged with the ball at the position facing the passage. In this case, the passive rack 21 should be manufactured from the same and single material, while a groove should be formed on the passive rack 21. |
