| 摘要 |
PURPOSE:To increase stroke volume and enable easy hobbing by contriving tooth shape of each rotor, in a screw rotor consisting of a four-tooth female rotor and a three-tooth male rotor, which are engaged with each other. CONSTITUTION:This screw rotor consists of a four-tooth female rotor (F) and a three-tooth male rotor (M), and the addendum (Af) of the female rotor (F) is set to be 3-6% of a pitch circle (Pf). The radius (SR4) of the angle formed by an arc (h2-j2) of the proceeding side of the female rotor (F)'s tooth-tip, and the radis (SR6) of the angle formed by an arc (b2-a2) of the follow-up side are limited to be within 10-50% of the addendum (Af). The straight line, which links the intersection point (Op) between the male rotor (M)'s pitch circle (Pm) and a follow-up tooth form with the central point (Om), controls the angle 'formed by a tangent line to the follow-up tooth form at the intersection point (Op) to be within 10-30 deg. to the follow-up side. These contrivances improve volume efficiency of the screw rotor and enables easier hobbing. |
