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Engineering

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Mechanical Engineering

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Equilibrium of a Rigid Body

3D Support Types for Stability and Motion

Description

Support reactions in three dimensions keep structures stable and in equilibrium. They stop unwanted translation and rotation, so a design can handle external forces safely and work as intended. These reactions are important in many structures and systems.

A ball and socket joint is one support th...

Transcript

根据具体应用,机械工程中会采用多种支座类型。  这些支座在三维力系中产生的支座反力可防止系统发生平移和转动。

考虑一个机械臂举起重物的情况。此处,关节 A 为球窝关节。由于球窝关节中不存在限制转动的力矩,该机械臂可绕任意轴自由旋转。然而,由于在三个维度上存在三个反作用力,该关节会限制平移运动。

或者,臂上的关节 B 为单个光滑销钉支座。该支座产生三个反作用力和两个力偶矩,并允许沿销钉轴线方向的转动。

机械臂的基座为固定支撑,沿三个方向均存在反作用力和力矩。

另一种支撑类型是铰链支撑,常用于门上。支撑处的三个反作用力限制了门的平移运动,而两个力矩则限制了门的转动。