| 摘要 |
<p>The moment (Mo) of an unbalanced force (Fr) of a screw rotor A1 is reduced by adjusting the number of leads of a threaded portion (2) of the screw rotor A1 to the sum of an integer and 0.5. The amount of unbalance for keeping a state of dynamic balance thereby decreases, and the drilling of a thread e for keeping a state of dynamic balance is made easier.</p> |
