In this study, SM45C-STKM13B hollow shaft of different thickness was joined by friction welding. After friction welding, we treated to specimen of annealing(post-weld heat treatment). The specimens were tested as-welded and post-weld heat treatment(PWHT). The mechanical properties including tensile test and vickers micro-hardness were examined. And then, the mechanical properties were compared for as-welded and PWHT in SM45C to STKM13B. Microstructure of joining part were examined in the weld interface and weld region and heat affected zone and base metal of weld parts.

This paper has been carried out the forming analysis, die stress analysis, and relevant tests for the straightness improvement of hollow shafts with blocktooth. Hollow forward extrusion is a process that a material in a die is pressed with a punch and the material is formed into the same direction through the gap of a mandrel and a bottom die. For an asymmetric shaped product, due to the difference of reduction ratios of the cross sections in its extruding, a phenomenon that the product bends from the difference of the flow speed comes to occur. As applying the key to the mandrel has a uniform flow speed, bending problem was solved. These were processed using Deform-3D as a finite-element analysis program. Analysis was compared with the experiment. Keyway height of the mandrel has been confirmed that the straightness best when it comes 0.1mm. These study are expected to be available as fundamental data in die design necessary for the manufacture of asymmetric goods in the future.

Robotic manipulators are increasingly deployed in complex environments or to perform complex tasks. Studies on dual-arm-robots have been continually carried out in robotics areas to provide robots in dangerous environments, similar to those which human beings would be normally in, without a special change to the working environment. In previous study, a dual-arm-robot has been designed. The robot, however, has some defects in its heavy weight and big shape. In order to reduce weight of an arm robot, the robot has been designed using a hollow-shaft-servo- assembly. The hollow-shaft-servo-assembly is composed of a hollow-shaft-servo-motor, a hollow- shaft-harmonic-drive, a hollow-shaft-brake, a hollow-shaft-encoder, and a servo-drive.