Study Chassis Welding Deformation For Holmium System Powersuite

Holmium laser medical system is an advanced system, which is suitable for high power applications such as the treatment of BPH, performing HoLEP or Ho LAP procedure. Comparison with traditional system, Laser need to touch the body, the treatment is very fast, and small hurt to the body, short recovery time. When laser cure the body, it need very precision, fiber can’t touch the good organs, such as kidney. In this case, the components for the system need to be accurate. The optics accuracy is the most important parameter, which have relation with the mechanical parts which support the laser module, chassis is the most important part. Chassis has the assembly relationship between laser optical bench, HVPS, chiller and motor.The chassis is welded by aluminum plate, easy to be deformation. When design the chassis, the critical dimension tolerance is ±0.1mm, angle ±0.5°.Design also need to control the assembly gap, the gap between front door and top cover is less than 2 mm, and it should be equal and flat.First, welding a chassis according to welding experience, when to check the dimension and assembly, it failed..Second, setup the model in Ansys to compute the temperature field of front plate and top plate, get the result of temperature difference.Third, compute the stress field according to the temperature field result, modify the deformation. Choose 3 different welding process to modify the deformation result, consider the welding length and welding number, get the deformation result, chose the best welding process.Last, produce chassis according to the best welding process, compare the deformation result with Ansys modification, it’s very close. According to design requirement, make the dimension test, check the assembly, the result is OK, the deformation problem is solved.