Limited slip differential and controlling method therefor

A limited slip differential comprising:

• an input shaft constantly connected to a differential case of a differential;
• an output shaft selectively connected to the input shaft via a clutch pack and constantly connected to a wheel;
• a medium-torque transmission means configured to press a clutch plate coupled to the input shaft such that the clutch pack is compressed and engaged;
• and
• a high-torque transmission means by which a hub coupled to the output shaft is moved in a state in which the input shaft and the output shaft are synchronized according to the engagement of the clutch pack and thus is selectively meshed with the clutch plate,
• wherein the high-torque transmission means comprises:
• a plate inner tooth formed on the clutch plate,
• the hub spline-coupled to an outer peripheral surface of the output shaft to be moved in an axial direction,
• a hub outer tooth formed on the hub in a shape corresponding to the plate inner tooth so as to be meshed with the plate inner tooth, and
• a second piston configured to press the hub such that the hub outer tooth is moved to a location at which the hub outer tooth is meshed with the plate inner tooth,
• wherein an output retainer is integrally formed in a cylindrical shape extending in an outer radial direction from a shaft portion of the output shaft,
• wherein one end of the hub is spline-coupled to the outer peripheral surface of an end portion of the output retainer, and
• wherein the other end of the hub is inwardly bent to be pressed by the second piston.