Abstract: Structure of a cross universal joint is achieved in which the fact that an excessive torque was applied to a universal joint due to a collision accident or mishandling can be easily determined afterwards. Protrusions 20, which are straight lines as seen from the outside surface sides of linking arm sections 15c of a yoke 12c, are formed on the outside surfaces of the linking arm sections 15c. When an excessive torque acts and the linking arm sections 15c are plastically deformed, the protrusions 20 change from a straight line to a non-straight line. From this change it is possible to easily confirm that an excessive torque has been applied to a cross universal joint that includes this yoke 12c. Moreover, when the space between the inside surfaces of the linking arm sections 15c is taken to be D, and the length in the axial direction of the linking arm sections 15c is taken to be L, the dimensions of the parts of the yoke 12c are regulated so that the relation 3<L/D?4 is satisfied.

Abstract: Structure of a cross universal joint is achieved in which the fact that an excessive torque was applied to a universal joint due to a collision accident or mishandling can be easily determined afterwards. Protrusions 20, which are straight lines as seen from the outside surface sides of linking arm sections 15c of a yoke 12c, are formed on the outside surfaces of the linking arm sections 15c. When an excessive torque acts and the linking arm sections 15c are plastically deformed, the protrusions 20 change from a straight line to a non-straight line. From this change it is possible to easily confirm that an excessive torque has been applied to a cross universal joint that includes this yoke 12c. Moreover, when the space between the inside surfaces of the linking arm sections 15c is taken to be D, and the length in the axial direction of the linking arm sections 15c is taken to be L, the dimensions of the parts of the yoke 12c are regulated so that the relation 3<L/D?4 is satisfied.

Abstract: In a torque sensor, coils and resistors constitute a bridge circuit, and the mutual connection part of the coils is connected to a power source via a coil drive unit. A control voltage, which varies in the square wave form, is supplied to the gate of a transistor in the coil drive unit so as to vary the voltage supplied to the coils in the square wave form. The output voltages which are the voltages between the coils and the resistors are input to the differential amplifier and the output voltage of the differential amplifier is held by a sample holding circuit to be supplied to a controller as the output voltage. The sample holding circuit holds the output voltage of the differential amplifier when the output voltages between the coils and the resistors are in the transient period. The controller detects the torque based on the output voltage of the sample holding circuit. An abnormal state monitoring unit is provided to detect an abnormal state of the coils.