In an apparatus accommodating a rotor of light alloy and a rotor shaft of steel secured to each other, the rotor shaft consists of a first shaft and a pair of second shafts integrally formed with or rigidly secured to the first shaft. The first shaft has a structure with a thermal coefficient of expansion close to that of the rotor whereas each of the second shafts has a structure with a thermal coefficient of expansion less than that of the first shaft.

An apex seal consisting of 3.0 to 4.0 wt % of C, 1.5 to 2.5 wt % of Si, 0.3 to 1.0 wt % Mn, 0.05 to 0.3 wt % of P, less than 0.1 wt % of S, 0.005 to 0.025 wt % of Mg or Ce, 0.5 to 2.0 wt % of Cu and/or 0.5 to 3.0 wt % of Ni, 0.4 to 1.0 wt % of Cr, 1.0 to 2.0 wt % of Mo and/or 0.1 to 0.5 wt % of V with the balance of Fe, being formed in the sliding surface portion with a sorbite matrix structure in which carbides are dispersed in a matrix of sorbite and in the matrix portion of the material other...

A method for producing a formed member made of a steel sheet according to the present invention is characterized by preparing a steel sheet material having tensile strength of 500 MPa or less and containing a nitriding element; forming a formed member having a predetermined shape by performing a plastic forming on the steel sheet material; and performing a nitriding treatment on the formed member so that an average hardness in the sheet thickness direction of the resultant steel sheet member is ...

An automobile bodyshell frame structure includes a generally elongated first panel member, and a generally elongated second panel member having opposite side edge portions connected to the first panel member to define a hollow between the first and second panel members. A filler is disposed within a portion of a cross-section of the hollow between the first and second panel members. This filler is provided on an inner surface of one of the first and second panel members and has an average compre...

Material characteristics that a foamed filler material (s) to be filled in a frame cross section (fr) should have are discussed. By using a material complying with the characteristics, the energy absorbability of the frame (fr) is effectively enhanced. In a frame structure (fr) for vehicle bodies in which a filler material is filled in at least part of the cross section of a frame, the filler material is set to a mean compressive strength of not less than 4 MPa and/or a maximum bending strength ...

A pair of left and right front frames are formed with brittle sections on proximal portions of the frames, by the provision of the smaller cross-sectional area than other sections of the frame. The brittle sections and their peripheral sections are processed so as to become approximately equal to the other sections of the front frames in axial compressive strength by way of a hardening treatment like quenching. In an early-phase of a collision, the hardened brittle sections will not buckle so as...