a liquid friction coupling is disclosed , which comprises a housing , which constitutes one coupling part and is filled with a viscous liquid , a shaft , which protrudes into the housing and constitutes the other coupling part , interdigitating disks , which are nonrotatably connected in alternation to the housing and to the shaft , respectively , and spacers disposed between the disks . in order to improve the torque characteristic during an operation involving liquid friction and to achieve a steeper rise of the hump torque , each of the outer or inner disks entirely or in part tends to exhibit a thermal deformation in an axial direction and a spacer ring is provided between each inner disk and an outer disk of an adjacent pair of disks .