In an automatic transmission having a torque converter with a pump
impeller, a turbine runner, and a stator, a stator shaft is provided to
support the stator on its outer periphery and to rotatably support a
transmission input shaft on its inner periphery. A magnetostrictive torque
sensor is provided to detect the magnitude of input torque transmitted to
the transmission input shaft. The magnetostrictive torque sensor includes
a magnetic material having a magnetostrictive property and attached onto
the outer periphery of the transmission input shaft, and a cylindrical
magnetic-property detector mounted on the inner periphery of the stator
shaft and arranged to be opposite to the magnetic material to detect a
change in a magnetic property of the magnetic material, occurring owing to
the input torque applied to the transmission input shaft.
