平面闭链六杆机构的自调结构及允差的研究

Study on Self-adjusting Structure and Permissble Errors in a Plane Closed-chain Six-bar Mechanism

分析了串联watt型六杆机构的无过约束结构、自由度配置及在此配置下的自调与允差。结果表明:多回路机构只有按每一回路的零过约束配置设计,才能确保整个机构的无过约束,且每一回路内存在自调构件时,机构较易实现无过约束配置;公共铰链采用V级副时,机构能同时保持平面运动特性;公共铰链的形位误差会直接影响两个回路的平面约束不确定性。

The paper analyzed non-overconstraint structure, freedom degree＇s configuration of the series Watt type six-bar mechanism, self-adjusting and the permissible errors under the configuration. It indicates the multiloop mechanism can insure whole mechanism non-overconstraint by non -overconstraint configuration design at each loop. When the self-adjusting components exist at the each loop, the mechanism can realize the non-over constraint configuration easily. The public hinge adopts the kinematic pair of grade five, the mechanism can keep the plane sport characteristics at the same time. Errors of profile and position of the public hinge will affect the plane constraint indetermination of two loops directly.