A torque detection device includes a first portion, a second portion disposed inside the first portion, and a connecting portion configured to link the first portion and the second portion. The first portion includes a first convex portion that projects toward the second portion. The second portion includes a second convex portion that projects toward the first portion. An inner surface of the first portion and a surface of the first convex portion link to the connecting portion. An outer surface of the second portion and a surface of the second convex portion link to the connecting portion. When torque is applied, the connecting portion deforms, and the first portion and the second portion are displaced relative to each other.

A torque detection device includes a first portion, a second portion disposed inside the first portion, and a connecting portion configured to link the first portion and the second portion. The first portion includes a first convex portion that projects toward the second portion. The second portion includes a second convex portion that projects toward the first portion. An inner surface of the first portion and a surface of the first convex portion link to the connecting portion. An outer surface of the second portion and a surface of the second convex portion link to the connecting portion. When torque is applied, the connecting portion deforms, and the first portion and the second portion are displaced relative to each other.

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.

The invention relates to a twisting torque sensor, comprising a transmission shaft (12) subjected to the torque to be measured, a reference shaft (14), and a device for measuring an angular deformation representing the torque to be measured between the two shafts. The torque sensor is characterised in that the transmission shaft (12) comprises a bore (24) extending from one end of the transmission shaft (12), referred to as input (28) of the shaft, to an opposite end, and in that the torque sensor comprises an enclosure (22) for confining the temperature of the two shafts, and a fluid circulation circuit including a portion made up of said bore (24), an injector (32) for injecting the fluid into the bore (24) at said input (28) of the shaft, and a fluid temperature sensor (34) in the fluid circulation circuit, the measured temperature being intended for correcting the torque measurement.

The invention relates to a twisting torque sensor, comprising a transmission shaft (12) subjected to the torque to be measured, a reference shaft (14), and a device for measuring an angular deformation representing the torque to be measured between the two shafts. The torque sensor is characterised in that the transmission shaft (12) comprises a bore (24) extending from one end of the transmission shaft (12), referred to as input (28) of the shaft, to an opposite end, and in that the torque sensor comprises an enclosure (22) for confining the temperature of the two shafts, and a fluid circulation circuit including a portion made up of said bore (24), an injector (32) for injecting the fluid into the bore (24) at said input (28) of the shaft, and a fluid temperature sensor (34) in the fluid circulation circuit, the measured temperature being intended for correcting the torque measurement.

A sensor system (10) and method for monitoring a powertrain (20) having a drive shaft (1). The sensor system (10) comprises an optical fibre (2) with a strain sensitive element (3). According to one aspect, a connection structure (4) is configured to hold at least a part of the optical fibre (2) with the strain sensitive element (3) at a radial distance (R2-R1) remote from the drive shaft (1) for amplifying the strain (S2) on the strain sensitive element (3) with respect to the strain (51) on the drive shaft (1). According to a further aspect, at least three respective lengths of one or more optical fibres follow parallel, e.g. helical, paths with respect to each other to distinguish different strain forces.

A sensor system (10) and method for monitoring a powertrain (20) having a drive shaft (1). The sensor system (10) comprises an optical fibre (2) with a strain sensitive element (3). According to one aspect, a connection structure (4) is configured to hold at least a part of the optical fibre (2) with the strain sensitive element (3) at a radial distance (R2-R1) remote from the drive shaft (1) for amplifying the strain (S2) on the strain sensitive element (3) with respect to the strain (51) on the drive shaft (1). According to a further aspect, at least three respective lengths of one or more optical fibres follow parallel, e.g. helical, paths with respect to each other to distinguish different strain forces.

An encoder includes an optical scale that has a phase difference plate, a light source section that irradiates the phase difference plate with light, and a light receiving section that receives the light from the phase difference plate, and outputs a signal corresponding to a received light intensity. The light emitted from the light source section is linearly polarized, and the light receiving section outputs a signal corresponding to a polarization state of the light from the phase difference plate.

The displacement detecting apparatus acquires a quantity of a relative rotational displacement between a scale and a detecting head, based on a change of outputs of the light-receiving elements. The displacement detecting apparatus acquires the quantity of the relative rotational displacement between the scale and the detecting head, by combining a quantity of a rough relative rotational displacement between the scale and the detecting head, which has been acquired from an output of the total of light quantities that are output from each of the light-receiving elements in the detecting head, with a quantity of a fine relative rotational displacement between the scale and the detecting head, which has been acquired from an incremental displacement signal that is output from each of the light-receiving elements in the detecting head.

The displacement detecting apparatus acquires a quantity of a relative rotational displacement between a scale and a detecting head, based on a change of outputs of the light-receiving elements. The displacement detecting apparatus acquires the quantity of the relative rotational displacement between the scale and the detecting head, by combining a quantity of a rough relative rotational displacement between the scale and the detecting head, which has been acquired from an output of the total of light quantities that are output from each of the light-receiving elements in the detecting head, with a quantity of a fine relative rotational displacement between the scale and the detecting head, which has been acquired from an incremental displacement signal that is output from each of the light-receiving elements in the detecting head.