Miniature electric motors help robots get a grip
TOOLS , PLANT & EQUIPMENT GRIPPER PERFORMANCE
PORTESCAP
Miniature electric motors help robots get a grip
Grippers are essential for robots engaged in pick-andplace applications . These electromechanical ‘ hands ’ allow objects to be grasped , manipulated and released , facilitating fast and precise interactions for low-mix , high-volume industrial processes . For the past three decades , pneumatic designs have been preferred by automation specialists - but this is changing . Electric grippers are proving a more modern solution , providing benefits in terms of efficiency , cost optimization , and space saving . At the heart of this advancement are miniature electric motors .
Guillaume Mougin , Product Manager at Portescap , explores how miniature electric motors are improving the performance of grippers in robotics .
Pick-and-place robots have become a staple in assembly , manufacturing , packaging and material handling applications , where repetitive tasks must be carried out with high speed and minimal errors . Able to operate in confined spaces , handle a wide variety of objects and conduct multiple tasks – these programmable robots have revolutionized many industries .
However , increasing demands upon robots have exposed the limitations of using pneumatic grippers in these applications . Operators require robots that offer more precise control of grasped objects , increased intelligence and additional functionality to support complex , modern processes . Robots must also be compact to maximize productivity in existing or limited floorspace . On top of this , end users want to reduce maintenance costs and energy usage to lower operating expenditure ( OPEX ). In all scenarios , electric grippers , powered by miniature electric motors , supersede pneumatic designs .
All under control
Control and grip force are arguably the most important performance parameters for grippers , and miniature electric motors excel in both regards . Precise control of position , speed and torque can be achieved more effectively than with other types of actuation systems – making electric grippers ideal for complex manufacturing .
In terms of grip force , this can be modulated by controlling a motor ’ s current or voltage . As a result , the gripper can delicately handle fragile objects , like electronics , or hold heavier , more robust loads , with a tighter grasp . Electric grippers offer the advanced control and grip options required to support a myriad of modern pick-and-place applications .
Do it again , and do it quickly One of the inherent benefits of using robots is increased process speed . Electric grippers compound this advantage thanks to motors that reach high speeds with incredibly quick acceleration . Rapidly opening and closing the grippers allows the pick , place and release mechanism to be completed quickly – reducing cycle times and improving productivity for automated systems . The lower the inertia of a specified gripper motor , the bigger the benefits .
However , fast cycle times must be backed by repeatability . Thankfully , electric motors can perform motions over and over again with high accuracy . In applications where consistent gripping and releasing actions are required , like bin picking , this is crucial .
Keeping things compact
The problem with a pneumatic gripper system is that it requires complex air supply systems like compressors , filters , regulators , and valves . This increases the footprint of a robot which , considering the production manager ’ s goal to achieve more in less space , is undesirable .
Conversely , miniature electric motors are designed to offer big power in a small package . Available space on a gripper is limited , but torque dense electric motors maximize it by offering easy integration without the need for bulky sub-systems . This can save space on the production line for operators and offers original equipment manufacturers ( OEMs ) the chance to downsize robot designs .
For further information , please visit www . portescap . com
94 PECM Issue 71