Magnetically induced torque measurement device and method based on torsional spring method

A magnetically induced torque measurement device, comprising:

• a rectangular outer frame (11) and five transmission shafts (A, B, C, A′, B′) secured on the rectangular outer frame, wherein a first transmission shaft (A), a second transmission shaft (B), a fourth transmission shaft (A′) and a fifth transmission shaft (B′) of the five transmission shafts are short shafts, upper ends of the first transmission shaft (A) and the second transmission shaft (B) are secured on an upper frame of the rectangular outer frame, lower ends of the fourth transmission shaft (A′) and the fifth transmission shaft (B′) are secured on a lower frame of the rectangular outer frame;
• the first transmission shaft (A), the second transmission shaft (B), the fourth transmission shaft (A′) and the fifth transmission shaft (B′) are pairwise symmetrical up and down;
• the first transmission shaft (A) and the fourth transmission shaft (A′) are coaxial, the second transmission shaft (B) and the fifth transmission shaft (B′) are coaxial, a third transmission shaft (C) of the five transmission shafts is a long shaft, and two ends of the third transmission shaft (C) are respectively secured on the upper frame and the lower frame of the rectangular outer frame;
• two gear sets, wherein a first gear set of the two gear sets comprises four gears (1, 2, 3, 4), and a second gear set of the two gear sets comprises four gears (1′, 2′, 3′, 4′);
• in the first gear set, a first gear (1) is secured on the first transmission shaft (A), a second gear (2) and a third gear (3) are secured on the second transmission shaft (B) and rotatable synchronously, a fourth gear (4) is secured on the third transmission shaft (C), the first gear (1) is meshed with the second gear (2), and the third gear (3) is meshed with the fourth gear (4);
• in the second gear set, a fifth gear (1′), a sixth gear (2′), a seventh gear (3′) and an eighth gear (4′) are symmetrically arranged with respect to the first gear (1), the second gear (2), the third gear (3) and the fourth gear (4) in the first gear set respectively;
• the fifth gear (1′) is secured on the fourth transmission shaft (A′), the sixth gear (2′) and the seventh gear (3′) are secured on the fifth transmission shaft (B′) and rotatable synchronously, and the eighth gear (4′) is secured on the third transmission shaft (C);
• a lifting platform (12), arranged on an upper end of the fourth transmission shaft (A′) and coaxial with the fourth transmission shaft (A′), wherein the lifting platform is disposed with an adjustment knob (13) configured to adjust a height of a lower detachable torsion spring and thereby change a height of a loading tray and make the loading tray suitable for MR systems with different magnet center heights;
• a protractor (14), attached to the lifting platform and coaxial with the fourth transmission shaft (A′), wherein the protractor is configured to measure a deflection angle of the loading tray;
• four adjustment belts (15), wherein the upper ends of the four adjustment belts are connected to an upper detachable torsion spring by a connecting sheet, the lower ends of the four adjustment belts are fixedly connected to an edge of the loading tray, each of the four adjustment belts is provided with a scale, and the lower end of each of the fourth adjustment belts is equipped with an adjustment buckle configured to change a length of the adjustment belt according to a height of the lifting platform;
• the loading tray (16), secured above the lower detachable torsion spring, wherein the loading tray is configured to fix a to-be-measured sample, and the loading tray is equipped with two indication marks configured to assist reading of the deflection angle of the loading tray;
• an MRI-compatible camera (17), secured on a middle location of the rectangular outer frame by MRI-compatible camera support (18) and configured to photograph the deflection angle of the loading tray;
• a detachable torsion spring set, comprising the upper detachable torsion spring (19) and the lower detachable torsion spring (20), wherein the upper detachable torsion spring (19) is secured on a lower end of the first transmission shaft (A) and rotatable along with the rotation of the first gear (1), the lower detachable torsion spring (20) is secured on the lifting platform and rotatable along with the rotation of the lifting platform;
• a knob (21), coaxially secured in the middle of the third transmission shaft (C), wherein the knob is provided with angle marking lines configured to display a rotation angle of the loading tray controlled by the knob, and the knob is configured to be rotated to drive the gear sets to rotate through the third transmission shaft (C);
• and
• an indicator (22), wherein an upper end of the indicator is secured on the upper frame of the rectangular outer frame, the indicator is vertically downward, a lower end of the indicator is aligned with an edge of the knob, and the indicator (22) is configured to obtain an angle change of the loading tray according to a scale when the knob is rotated.