A propeller shaft (1) that is a power transmission shaft has a shaft member (2) as a tubular body made of iron-based metal and a balance weight (3) made of iron-based metal and welded to an outer peripheral surface of this shaft member (2). At least a part of the balance weight (3) of the propeller shaft (1) is covered with a sacrificial metal coating (4) made of sacrificial corrosion prevention material that contains metal whose ionization tendency is higher than that of metal forming the shaft member (2). With this, it is possible to suppress local progression of corrosion at a periphery of the balance weight (3) and improve durability of the propeller shaft (1).

A propeller shaft (1) that is a power transmission shaft has a shaft member (2) as a tubular body made of iron-based metal and a balance weight (3) made of iron-based metal and welded to an outer peripheral surface of this shaft member (2). At least a part of the balance weight (3) of the propeller shaft (1) is covered with a sacrificial metal coating (4) made of sacrificial corrosion prevention material that contains metal whose ionization tendency is higher than that of metal forming the shaft member (2). With this, it is possible to suppress local progression of corrosion at a periphery of the balance weight (3) and improve durability of the propeller shaft (1).

Apparatus for containing a flywheel comprising: a flywheel; a shaft; a bearing arrangement for supporting the shaft; and a housing for housing the flywheel, the shaft and the bearing arrangement; wherein the flywheel is mounted on the shaft, the shaft is mounted to the bearing arrangement, and the bearing arrangement is mounted to the housing; wherein the flywheel has a rim formed by a circumferential face of the flywheel, and a hub formed by a central region of the flywheel, the hub being wider, axially, than the rim such that a circumferential contact surface is formed by the hub that is coaxial with the rim; wherein the housing comprises an annular force transfer region that faces, and is concentric with, the contact surface; and wherein, in use, excessive radial movement of the flywheel results in the contact surface contacting the transfer region.

A torsional vibration damping arrangement for a drivetrain of a vehicle, having a carrier arrangement which is rotatable around an axis of rotation, a deflection mass movable in circumferential direction relative to the carrier arrangement, carrier arrangement and the deflection mass are coupled to be rotatable relative to one another via restoring elements arranged in circumferential direction that extend from the deflection mass in direction of the carrier arrangement. A restoring element is deformable around a force application point which is movable in radial direction under centrifugal force and which is associated with the restoring element. The movable force application point is acted upon by a preloading force acting radially in direction of the axis of rotation by a preloading spring. A main axis of the preloading spring and a main axis of the restoring element do not extend coaxially.

A constant stress solid disk rotor of a flywheel has an outer shape having a plane-symmetric upper surface and lower surface, an outer circumferential radius b, and a rotation center thickness h.sub.0, and includes a thickness decreasing region which decreases monotonously in thickness from a rotation center to a connection radius a and a constant thickness region located on an outer edge of the thickness decreasing region and having a constant thickness h.sub.a from the connection radius a to the outer circumferential radius b. Shape parameters including the outer circumferential radius b, the rotation center thickness h.sub.0, the connection radius a, and the outer edge thickness h.sub.a satisfy an equation below. Here, ? is a Poisson's ratio of a rotor material.

[00001]$\frac{a}{b}=\sqrt{\frac{1}{2}\left(-\frac{2}{1-v}\left(1+v-\frac{2}{\ln \left(\frac{h_a}{h_0}\right)}\right)+\sqrt{{\left(\frac{2}{1-v}\left(1+v-\frac{2}{\ln \left(\frac{h_a}{h_0}\right)}\right)\right)}^2+\frac{4\left(3+v\right)}{1-v}}\right)}$

A solid steel flywheel rotor having improved material properties offers improved energy storage at reduced cost. A process for manufacturing the rotor is also provided.

A solid steel flywheel rotor having improved material properties offers improved energy storage at reduced cost. A process for manufacturing the rotor is also provided.

A solid steel flywheel rotor having improved material properties offers improved energy storage at reduced cost. A process for manufacturing the rotor is also provided.

A solid steel flywheel rotor having improved material properties offers improved energy storage at reduced cost. A process for manufacturing the rotor is also provided.