Power transmission interrupting device and limited-slip differential

A limited-slip differential comprising:

• a case member,
• a first rotating member housed inside the case member,
• a second rotating member housed inside the case member and disposed so as to be rotatable relative to the first rotating member around a common rotational axis;
• a third rotating member housed inside the case member and disposed so as to be rotatable relative to the first rotating member and the second rotating member around the common rotational axis;
• an interrupting member that is restrained from rotating relative to the first rotating member, has engaging teeth engaging with the second rotating member, and is movable in an axial direction between a coupling position at which the engaging teeth engage with the second rotating member and an uncoupling position at which the engaging teeth do not engage with the second rotating member;
• and
• a moving mechanism that moves the interrupting member in the axial direction, wherein:
• in a state where the engaging teeth of the interrupting member are not engaged with the second rotating member, power input into the first rotating member is allocated to the second rotating member and the third rotating member so as to allow for differential motion thereof;
• as the engaging teeth of the interrupting member engage with the second rotating member, differential motion of the first rotating member and the second and third rotating members is limited;
• the moving mechanism has an annular magnetic flux generation unit having a coil that generates magnetic flux when current is applied thereto, a holder unit that holds the magnetic flux generation unit, and a moving member that constitutes a magnetic path of the magnetic flux and moves in the axial direction with the interrupting member;
• and
• the holder unit includes:
• a yoke made of a soft magnetic material and having a cylindrical part that faces the magnetic flux generation unit in a radial direction;
• and a restraint member having an axial movement restraining part that is fixed to the yoke and restrains the magnetic flux generation unit from moving in the axial direction relative to the cylindrical part, and a rotation restraining part that is locked in a locking portion provided in the case member and restrains the yoke from rotating relative to the case member.