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) .

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).

The rotary body according to the present invention is made of resin and attached to a crankshaft. The rotary body has an outside plate element and an inside plate element which are attached to an outside surface and an inside surface of an arm portion of the crankshaft, respectively, and a pair of filler elements disposed between the outside plate element and the inside plate element and on both sides of the arm portion. The outside plate element and the pair of the filler elements are coupled to each other, and the pair of the filler elements and the inside plate element are coupled to each other.

A flywheel system comprises a flywheel rotor comprising a rotor disc and a rotor shaft and has a longitudinal axis extending centrally through the rotor disc and the rotor shaft. The system further comprises a journal assembly configured to facilitate rotation of the flywheel rotor. The journal assembly comprises a sleeve having an aperture extending therethrough from a first end to a second, opposite end, a rod at least partially disposed within the aperture of the sleeve, and a nut coupled to a portion of the rod. The rod has a length greater than the sleeve such that a portion of the rod extends axially beyond the first end of the sleeve. A method of forming the flywheel comprises coupling the rod to the rotor shaft and pulling the second end of the rod to tension the rod. The nut maintains the tension in the rod when coupled thereto.

A new non-contacting magnetic “snubber” bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

A new non-contacting magnetic “snubber” bearing is provided for application to rotating systems such as vehicular electromechanical battery systems subject to frequent accelerations. The design is such that in the equilibrium position the drag force of the snubber is very small (milliwatts). However in a typical case, if the rotor is displaced by as little as 2 millimeters a large restoring force is generated without any physical contact between the stationary and rotating parts of the snubber bearing.

A bearing and flywheel system can include a first bearing portion having an opening of a first dimension there through and a central longitudinal axis, a second bearing portion having a second dimension, the second dimension being smaller than the first dimension, and a flywheel coupled to the second bearing portion. The bearing portions can include high-temperature superconductor(s) and/or magnets. The second bearing portion can be disposed at least partially within the opening through the first bearing portion. A gap can exist between an outer surface of the second bearing portion and an inner surface of the first bearing portion. The second bearing portion can be configured to rotate relative to the first bearing portion.

A flywheel system comprises a flywheel rotor comprising a rotor disc and a rotor shaft and has a longitudinal axis extending centrally through the rotor disc and the rotor shaft. The system further comprises a journal assembly configured to facilitate rotation of the flywheel rotor. The journal assembly comprises a sleeve having an aperture extending therethrough from a first end to a second, opposite end, a rod at least partially disposed within the aperture of the sleeve, and a nut coupled to a portion of the rod. The rod has a length greater than the sleeve such that a portion of the rod extends axially beyond the first end of the sleeve. A method of forming the flywheel comprises coupling the rod to the rotor shaft and pulling the second end of the rod to tension the rod. The nut maintains the tension in the rod when coupled thereto.