The rigid arm power manipulator is an automated mechanical device that is used in a wide range of applications in the field of machine technology. They can be found in industrial manufacturing, medical, military, semiconductor manufacturing and space exploration. So what are the design requirements for a rigid-arm power-assisted manipulator?
1. The arm should have a high load-bearing capacity, good rigidity and light weight
The rigidity of the arm directly affects the smoothness, movement speed and positioning accuracy of the rigid arm type manipulator when gripping the workpiece. If the rigidity is poor, the arm will be distorted and deformed in use, generating vibrations, or the workpiece will be stuck and unable to work when moving. Because of this, rigid arm-assisted manipulators generally use good rigid guide bars to increase the rigidity of the arm, and the rigidity of each support and connection must also be required to ensure that it can withstand the required driving force.
2. The movement speed of the arm should be appropriate and the inertia should be small
The moving speed of the rigid arm power manipulator is generally determined according to the production rhythm of the product, but it is undesirable to pursue high speeds. When the arm from a stationary state to reach the normal speed of movement begins, from the constant speed to reduce to stop motionless for braking. The speed change process is the speed characteristic curve. The lighter the weight of the arm, the better the stability of its start and stop.
3、Arm movement should be flexible
The structure of the rigid arm power manipulator should be compact and small, so that the arm movement can be light and flexible. Adding rolling bearings to the arm or using ball guides can also make the arm move quickly and smoothly. In addition, for cantilevered rigid arm-assisted manipulators, the arrangement of the parts on the arm needs to be considered, i.e. the weight of the arm moving parts needs to be calculated in order to weigh the torque at the centre of rotation, lifting and support. A bias towards torque is very detrimental to arm movement. If the torque is too high, it can cause vibrations in the arm and a kind of sinker phenomenon can occur during lifting and lowering, which also affects the flexibility of the movement. In severe cases, the arm and the column can get stuck. Therefore, the arm is designed so that the centre of gravity of the arm passes through the centre of rotation, or as close to it as possible, in order to reduce the deflecting torque.