合的率单：互相啮合传动的一对齿廓在任一位置时的传动比，等于其 连心线O1O2被固定的节点所分成的两线段之反比。 The common normal of the tooth profiles,at all contact points within the mesh,must always pass through a fixed point on the line of centers,called the pitch point pressure angle rotated in direction of driven gear pitch circles line of action pitch point (common normal) leaving contact (length of action Z angle of recess) angle of approach driving (cw) driven (cew) Care of action beginning contact center distance C addendum circles 上泽克夏大粤 8 Pressure angle (angle between force and motion Pressure angle rotated in direction of driven gear Velocity at pitch point Axis of transmission or line of action (common normal)is tangent to Addendum of pinionp both base circles Pitch radius of pinion p 09 Common tangent- gear Pitch radius of gear g Pitch point Driven(CCW) Driving (CW) Base circle of pinion Base circle of gear- Pitch circles Addendum of gear ag9 The common normal of the tooth profiles, at all contact points within the mesh, must always pass through a fixed point on the line of centers, called the pitch point Fundamental Law of Gearing 齿廓啮合的基本定律：互相啮合传动的一对齿廓在任一位置时的传动比，等于其 连心线O1O2被固定的节点所分成的两线段之反比。 Pressure angle (): angle between force and motion