Abstract: A synchronous rotating type scroll fluid machine has a first scroll member driven by a shaft of a first motor and having an end plate and a scroll wrap protruding from a surface of the scroll end plate, and a second scroll member driven by a shaft of a second motor and having a scroll end plate and a scroll wrap protruding from a surface of the scroll end plate. The machine further has a mounting structure for mounting the scroll members such that the axes of the scroll members are offset from each other and that said scroll wraps of the scroll members mesh with each other. Thrust balancing arrangements are provided for attaining a balance between the thrusting forces acting on each said scroll member, both at the mounting structure and said scroll members. The thrust balancing arrangement includes through-bores formed in the respective motor shafts and serving as passage bores for discharging a compressed gas.

Abstract: A rotating magnetic head device in a magnetic recording and reproducing apparatus constructed as follows:(1) A cylinder is composed of an upper fixed cylinder and a lower fixed cylinder, a recess is provided in the part of the upper fixed cylinder where a magnetic tape is not wound, and an inner lid, a top case or the like of the tape cassette is arranged (inserted) in the recess in overlapping fashion, thereby making it possible to reduce the size of the apparatus.