Planetary Carrier of Automatic Transmissions for Automobile
The cover shows a newly-developed sintered planetary carrier for use in the planetary gear mechanism of automatic transmissions in automobiles (the units are by courtesy of AISIN AW Co., Ltd.).
Carriers require a complex shape with space for installation of the planetary gears as well as boss and hub parts for input/output. By applying 2-piece sinter-diffusion bonding, it was possible to achieve near-net shape, minimizing post-machining work.
The sinter-diffusion bonding process is a technology in which diffusion bonding is performed simultaneously with sintering utilizing the difference in the dimensional change in the pieces during sintering. Using this process, Hitachi Powdered Metals developed a new sintered-type carrier in which economy is achieved by adopting a simple binder-free process, while excellent positional accuracy between the two pieces is realized by radial bonding.