Research On Anti-rotation Countermeasures Of Scroll-type Non-contact Vacuum Chuck Workpiece

As one of the important transportation methods on the automated production line,the vortex non-contact vacuum gripper has been widely used in the industries such as automated production and assembly.Compared with other non-contact transportation technologies,vortex non-contact vacuum gripper has a simple structure,small air consumption,quick response and small noise,which make it has a broad application prospect.However,the existence of the rotating flow of the gripper will cause the rotation of the workpiece when it's sucked,and the rotation of the workpiece has a great impact on the stability of the non-contact vacuum suction,seriously it will lead to the failure of the non-contact vacuum suction.There for,it's necessary and urgent to study the rotation mechanism of the workpiece during non-contact vacuum suction and propose an effective anti-rotation technology for the gripper.The research work of the paper mainly includes the following aspects:(1)Analyze the rotation mechanism of the workpiece when the vortex non-contact vacuum gripper works,and then a double-vortex non-contact vacuum gripper is proposed.According to the arrangement of the double-vortex,two types of gripper structures,concentric and side-byside,are designed.(2)The internal flow field of the new gripper is simulated,and the change rule of the radial pressure distribution of the suction surface and the tangential velocity distribution of the swirling flow with the suction gap and the air supply pressure are analyzed.Finally,the theoretical suction force of the new gripper under different working conditions is derived based on the simulation results.(3)A test platform for suction characteristics of new gripper is established,and the suction force of the gripper,the rotation speed and the oscillation amplitude of the workpiece under different working conditions are tested.It's found that the suction force of the gripper increased first and then decreased with the increase of the gap.The air supply pressure has a greater influence on the suction force of the gripper,which is approximately a linear growth relationship.At the same time,it's found that the new gripper can effectively restrain the rotation of the workpiece during the suction process under different working conditions.Finally,the influence of suction gap,air supply pressure,and the weight of workpiece on the oscillation amplitude of the workpiece are analyzed.The results show that the oscillation amplitude of the workpiece is independent of the suction gap,and the dynamic balance position of the workpiece is related to the inherent characteristic of the gripper and has nothing to do with other factors.And the oscillation amplitude of the workpiece increases significantly with the increase of the air supply pressure and the weight of the workpiece.At the same time,the suction performance of the new double-vortex gripper is compared with the existing singer-vortex gripper.It's found that the single-vortex has a large suction force and a small workpiece amplitude,but the rotation speed of the workpiece is fast,and the double-vortex gripper can effectively restrain the rotation of the workpiece.These results have important reference value for the further optimization of the double-vortex non-contact vacuum gripper.