A rotary member inspection method of inspecting a rotation operation of a rotary member configured to rotate about a rotation shaft includes: causing the rotary member to perform forward rotation and thereafter perform reverse rotation; acquiring one or both of a difference value between a rotating torque at a time of the forward rotation of the rotary member and a rotating torque at a time of the reverse rotation of the rotary member, and an inertia force at a time of switching from the forward rotation to the reverse rotation of the rotary member; and determining whether a rotation failure of the rotary member is present based on one or both of the acquired difference value and the acquired inertia force and a threshold set in advance.

A jointing structure includes a jointing member and at least two abutting members. The at least two abutting members are disposed on the jointing member. The jointing member includes a surface and a plurality of side surfaces surrounding the surface, and the at least two abutting members are disposed on at least two of the side surfaces respectively.

A jointing structure includes a jointing member and at least two abutting members. The at least two abutting members are disposed on the jointing member. The jointing member includes a surface and a plurality of side surfaces surrounding the surface, and the at least two abutting members are disposed on at least two of the side surfaces respectively.

A torque measurement tool and method of use is presented which comprises a first outer shaft extending along a longitudinal axis and containing a second inner shaft positioned within the first outer shaft and extending along the longitudinal axis, A flexible coupling is positioned between the first outer shaft and the second inner shaft. A shear stress sensor is positioned within the second inner shaft, is exposed to the first outer shaft and contacts the flexible coupling.

A torque measurement tool and method of use is presented which comprises a first outer shaft extending along a longitudinal axis and containing a second inner shaft positioned within the first outer shaft and extending along the longitudinal axis, A flexible coupling is positioned between the first outer shaft and the second inner shaft. A shear stress sensor is positioned within the second inner shaft, is exposed to the first outer shaft and contacts the flexible coupling.

In some examples, a downhole torque measurement tool comprises a first surface of a structure and a second surface of the structure. The second surface is facing the first surface, and a shear stress sensor is positioned on the first surface. A flexible coupling is positioned between the shear stress sensor and the second surface, and the flexible coupling is coupled to the first and second surfaces.

In some examples, a downhole torque measurement tool comprises a first surface of a structure and a second surface of the structure. The second surface is facing the first surface, and a shear stress sensor is positioned on the first surface. A flexible coupling is positioned between the shear stress sensor and the second surface, and the flexible coupling is coupled to the first and second surfaces.

A sensor is provided, in particular a turning angle or torque sensor, with a stator at rest in relation to surroundings and a rotor that can be rotated in relation to the surroundings and the stator. The stator features a support with which the stator is secured against rotation in relation to the surroundings. A printed circuit board is provided, on which an electronic circuit arrangement of the stator is provided. The support is a pin and the electronic circuit arrangement and the pin are at least partially enveloped by a casting compound. One end of the pin protrudes from the casting compound, and the pin is fixed in or on the printed circuit board or in or on the casting compound.

A sensor is provided, in particular a turning angle or torque sensor, with a stator at rest in relation to surroundings and a rotor that can be rotated in relation to the surroundings and the stator. The stator features a support with which the stator is secured against rotation in relation to the surroundings. A printed circuit board is provided, on which an electronic circuit arrangement of the stator is provided. The support is a pin and the electronic circuit arrangement and the pin are at least partially enveloped by a casting compound. One end of the pin protrudes from the casting compound, and the pin is fixed in or on the printed circuit board or in or on the casting compound.

A series elastic actuator includes a gear, a mounting recess formed in the gear, an elastic body provided in the mounting recess, an output body, a through-hole penetrating the gear, a shaft passing through the through-hole, a pair of bearings to radially support the shaft, and a pair of bearing mounting recesses to receive the pair of bearings. The gear is configured to rotate by a rotational power source. A rotation force of the gear is transmitted to the gear by the elastic body. The through-hole may extend in an axial direction, and the pair of bearings may be spaced apart from each other in the axial direction. The pair of bearing mounting recesses may be formed at opposite ends of the through-hole.