Outer wall structure of a torque converter and others

An outer wall structure of a torque converter including an input housing having an end portion, and a pump impeller shell having an end portion fixed to said end portion of the input housing, characterized in that one of said end portions is provided at the outer peripheral surface with a surface portion of a relatively small diameter, which continues to a free end of its end portion, and a surface portion of a relatively large diameter, which continues to said surface portion of the relatively small diameter, the other of said end portions is provided at the inner surface with surface portions fitted to said surface portions of said relatively small and large diameter portions, a space for accumulating spatter and cut powder therein is formed between said inner peripheral surface and said surface portion of said relative small diameter, said space opening into said housing at said one of said end portions and both of said end portions are fixed together by a weld portion formed at and in the vicinity of the end of said other of the end portions.