A lubricity tester unit may comprise a housing, a shaft, wherein a first end of the shaft is disposed at a first end of the housing, wherein the shaft extends through housing along a central axis of the housing, and an encoder, wherein the encoder is disposed on an internal wall of the housing, wherein the shaft is disposed through a hole in the encoder, wherein the encoder is an optical encoder configured to measure angular position of the shaft. The lubricity tester unit may further comprise rotating rings, wherein the rotating rings are coupled to a second end of the shaft, a friction inducing surface, wherein the friction inducing surface is disposed around the rotating rings, a first sensor, wherein the first sensor is disposed through the housing, and a second sensor, wherein the second sensor is disposed through the housing.

The system and method determines the torque applied to a rotating shaft by a load. A first sensor detects rotation of a first wheel and a second sensor detects rotation of a second wheel. A third sensor is proximate to the first sensor. A processor determines: 1) a magnitude of a phase angle (.sub.A) based on the first and second sensors and having an unknown sign; 2) a magnitude of a phase angle (.sub.B) based on the second and third sensors and having an unknown sign; and 3) a magnitude of a phase angle (.sub.C) based on the first and third sensors and having a known sign. The processor determines a sign of the phase angle (.sub.A) based on the values of the phase angles (.sub.B) and (.sub.C) and determines a torque value from the load applied to the shaft at least in part based on the magnitude and sign of the phase angle (.sub.A).

An oarlock-installation for a boat in which an oarlock is mounted on an upright pin for angular displacement about the pin during rowing of the boat, the oarlock-installation comprising a mechanism for deriving measurements of angular displacement of the oarlock from a datum angle about the pin during the rowing, a mechanism for deriving measurements of force exerted on the oarlock during the rowing, and a mechanism for deriving measurement of rowing power from the measurements of force and the measurements of angular displacement. The rowing-boat oarlock-installation may also comprises a power module, attached to the oarlock, which is responsive to rowing of the rowing-boat to derive force measurements in accordance with rowing forces exerted on the power module during the rowing.

An oarlock-installation for a boat in which an oarlock is mounted on an upright pin for angular displacement about the pin during rowing of the boat, the oarlock-installation comprising a mechanism for deriving measurements of angular displacement of the oarlock from a datum angle about the pin during the rowing, a mechanism for deriving measurements of force exerted on the oarlock during the rowing, and a mechanism for deriving measurement of rowing power from the measurements of force and the measurements of angular displacement. The rowing-boat oarlock-installation may also comprises a power module, attached to the oarlock, which is responsive to rowing of the rowing-boat to derive force measurements in accordance with rowing forces exerted on the power module during the rowing.

An example device includes an inner element, an outer surrounding element, and a plurality of connecting flexural elements coupled between the inner element and the outer surrounding element. The inner element has a plurality of reflective surface areas that are configured to reflect light to a sensor. The outer surrounding element surrounds the inner element. The plurality of connecting flexural elements allow the inner element to move relative to the outer surrounding element.

An example device includes an inner element, an outer surrounding element, and a plurality of connecting flexural elements coupled between the inner element and the outer surrounding element. The inner element has a plurality of reflective surface areas that are configured to reflect light to a sensor. The outer surrounding element surrounds the inner element. The plurality of connecting flexural elements allow the inner element to move relative to the outer surrounding element.

Systems and methods for measuring displacement parameters of rotating shafts and couplings are disclosed. In some aspects, a measurement system includes a shaft extended in a longitudinal direction and a target wheel configured to rotate with the shaft. The target wheel includes sensor targets circumferentially distributed around the target wheel. Some of the targets are slanted in the longitudinal direction and some of the targets are parallel to the longitudinal direction. The measurement system includes a sensor array including at least three sensors mounted radially around the shaft and configured to detect the sensor targets as the target wheel rotates with the shaft. The measurement system includes a controller configured to receive sensor signals from the sensors and determine, based on the sensor signals, at least an axial displacement measurement of the shaft in the longitudinal direction and a radial displacement measurement of the shaft.

Systems and methods for measuring displacement parameters of rotating shafts and couplings are disclosed. In some aspects, a measurement system includes a shaft extended in a longitudinal direction and a target wheel configured to rotate with the shaft. The target wheel includes sensor targets circumferentially distributed around the target wheel. Some of the targets are slanted in the longitudinal direction and some of the targets are parallel to the longitudinal direction. The measurement system includes a sensor array including at least three sensors mounted radially around the shaft and configured to detect the sensor targets as the target wheel rotates with the shaft. The measurement system includes a controller configured to receive sensor signals from the sensors and determine, based on the sensor signals, at least an axial displacement measurement of the shaft in the longitudinal direction and a radial displacement measurement of the shaft.

A torque sensor is provided that includes a deformable plate that includes an inner part and an outer part. The torque sensor may also include one or more elastic elements that connect the inner part and the outer part. The torque sensor may also include a transducer mounting plate that is rigidly connected to the inner part of the deformable plate. In certain embodiments, the elastic elements include at least one serpentine-shaped elastic element. In other embodiments, the elastic elements may include a beam structure. In some embodiments, the torque sensor includes a plurality of zeroing pins and zeroing pin slots which, when engaged, constrain the rotation of the torque sensor to a smaller zeroing range. In certain embodiments, the torque sensor may also include a plurality of hard stop pins that engage a stopping when an applied torque exceeds a predetermined threshold.

A torque sensor is provided that includes a deformable plate that includes an inner part and an outer part. The torque sensor may also include one or more elastic elements that connect the inner part and the outer part. The torque sensor may also include a transducer mounting plate that is rigidly connected to the inner part of the deformable plate. In certain embodiments, the elastic elements include at least one serpentine-shaped elastic element. In other embodiments, the elastic elements may include a beam structure. In some embodiments, the torque sensor includes a plurality of zeroing pins and zeroing pin slots which, when engaged, constrain the rotation of the torque sensor to a smaller zeroing range. In certain embodiments, the torque sensor may also include a plurality of hard stop pins that engage a stopping when an applied torque exceeds a predetermined threshold.