The torque detection of the gear spindles is detected by the torque measuring device. It can be judged by the torque detection whether the torque reaches the maximum torque required by the design, which is very important for ensuring the safe use of the gear spindles. The principle of the common torque measuring device can be divided into the strain gauge method, the phase difference measurement method, the two-channel phase difference measurement, and the three-channel phase difference measurement with compensation.
The strain gauge method is a traditional method for measuring the torque of a gear spindles. It is a four-strain gauge on the middle section of the coupling to form a wheatstone bridge. It receives and transmits electrical signals through electromagnetic induction technology，thereby measuring the deformation and then inferring the transmitted torque. The phase difference method is to provide an outer ring gear at both ends of the coupling, and the non-contact type sensor is used to measure the phase difference of the ring gear teeth, thereby calculating the torsional deformation between the two outer ring gears, and multiplying the torsional stiffness to obtain the transmission of the torque.
The two-channel phase difference measurement is that a toroidal coil is installed in the inner ring gear. When the coil is energized, the coil generates an electromagnetic field. When the outer ring gear fixed on the shaft rotates, the periodic variation of the inner and outer ring gear gaps causes periodic changes of the magnetic flux. A change in the induced electric force is generated to measure the relative position of the rotational direction. When the displacement of the gear spindles occurs in the vertical direction, the upper gap of the outer ring gear becomes smaller, and the lower gap becomes larger, resulting in an average sinusoidal voltage, which compensates for the vertical displacement during the operation of the coupling. Influence, the principle of the two ring gears is the same, the deformation is measured by the phase difference of the sinusoidal voltage generated by the two coils.
The compensated three-channel phase difference measurement is that the outer ring gear is mounted on a coupling barrel that does not transmit torque. The outer gear ring should be as close as possible to the outer ring gear coupled to the other end, because the axial distance between the two outer ring gears is small. Therefore, the additional displacement caused by horizontal and vertical movement for other reasons is also small, and this small deviation can also be compensated by adding an external ring gear at the same axial distance on the other side of the outer ring gear.www.morayshaft.com