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).

Systems, methods, and devices of the various embodiments provide a compact vibration damper configured to be remotely-tunable and/or self-tuning. In various embodiments, a flywheel may be coupled to a shaft that spins a rotary damper. A linear actuator may operate a scissor assembly that moves the flywheel thereby changing the mass moment of inertia of the spinning flywheel without changing the actual mass of the flywheel. The linear actuator may move the scissor assembly and flywheel to tune the compact vibration damper. In additional embodiments, opposing rotary springs may be coupled to the shaft that spins the rotary damper.

Systems, methods, and devices of the various embodiments provide a compact vibration damper configured to be remotely-tunable and/or self-tuning. In various embodiments, a flywheel may be coupled to a shaft that spins a rotary damper. A linear actuator may operate a scissor assembly that moves the flywheel thereby changing the mass moment of inertia of the spinning flywheel without changing the actual mass of the flywheel. The linear actuator may move the scissor assembly and flywheel to tune the compact vibration damper. In additional embodiments, opposing rotary springs may be coupled to the shaft that spins the rotary damper.

Cryocooler assemblies are provided that can include: a first mass configured to generate mechanical responses; a second mass operably engaged with the first mass; and an assembly between the first and second mass, the assembly configured to allow movement of the first mass in relation to the second mass. Methods for isolating mechanical responses within a cryocooler assembly are provided. The methods can include: generating a mechanical response about a first mass within a cryocooler assembly; suspending the first mass in relation to a second mass of the assembly; and operatively engaging the second mass as a cold source for the cryocooler assembly.

Cryocooler assemblies are provided that can include: a first mass configured to generate mechanical responses; a second mass operably engaged with the first mass; and an assembly between the first and second mass, the assembly configured to allow movement of the first mass in relation to the second mass. Methods for isolating mechanical responses within a cryocooler assembly are provided. The methods can include: generating a mechanical response about a first mass within a cryocooler assembly; suspending the first mass in relation to a second mass of the assembly; and operatively engaging the second mass as a cold source for the cryocooler assembly.

Cryocooler assemblies are provided that can include: a coldhead operatively engaged with a chamber configured to retain cryofluid; and a first thermally conductive mass thermally engaged with the cryofluid. Methods for providing one or more cold sources from a cryocooler are also provided. The methods can include operatively engaging at least the cryofluid of the cryocooler with one or more thermally conductive masses.

Cryocooler assemblies are provided that can include: a coldhead operatively engaged with a chamber configured to retain cryofluid; and a first thermally conductive mass thermally engaged with the cryofluid. Methods for providing one or more cold sources from a cryocooler are also provided. The methods can include operatively engaging at least the cryofluid of the cryocooler with one or more thermally conductive masses.

A delivery device having a connecting rod, and a method for controlling a delivery device having a connecting rod and at least one balance weight, includes a part that is permanently connected to a shaft, on which part a pivot bearing is situated, by which the first end region of the connecting rod is accommodated by the part, in particular such that the connecting rod is able to be driven in eccentric manner, balance weights being situated on the part so as to be displaceable by a first drive, a first computer being provided on the part, which controls the displacement of the balance weights.

A counterweight forms a crankshaft of an engine, and includes: an arm connecting a crank journal and crank pin of the crankshaft; a neck extending from a first connection face of the arm in a direction opposite to the crank pin; and a substantially fan-shaped weight continuous with a portion of the neck opposite to the crank journal. The weight has left and right shoulders continuous with the neck, and each of the shoulders is tilted to be away from the neck at an angle with respect to a horizontal line orthogonal to a crankshaft center when viewed along the crankshaft center, the angle being 15 or more and 22.5 or less.