Shock absorbing device for an arbor of a wheel set of a micromechanical device, in particular a timepiece movement, said shock absorbing device comprising: - a pivot module, - a support provided with a housing accommodating the pivot module, the support being surmounted by a peripheral shoulder extending from a rim of the housing towards the centre of the support, said peripheral shoulder comprising a plurality of recesses opening onto the housing with at least one of said recesses forming a so-called locking recess, - a spring ring able to adopt respectively a so-called mounting position and a so-called attachment position with respect to the support, said spring ring being arranged between the peripheral shoulder and the pivot module in order to exert an elastic force on said pivot module when the spring ring is in the attachment position, said spring ring being provided on the outer periphery thereof with a plurality of tabs with at least one of said tabs forming a so-called locking tab, the plurality of tabs extending radially away from the centre of the support and giving spring ring an outer diameter which exceeds the inner diameter of the peripheral shoulder, the plurality of tabs cooperating with the peripheral shoulder during the mounting and bayonet attachment of the spring ring to the support, the recesses of the support having dimensions at least equal to those of the tabs to allow the engagement of the tabs in the corresponding recesses during mounting, the shock absorbing device being characterized in that: - the number of recesses is greater than the number of tabs with at least one extra recess forming the locking recess, - in the attachment position, one part of the tabs is positioned under the peripheral shoulder and another part comprising at least said locking tab is positioned in said locking recess, said locking recess being surrounded on each side by a tab positioned under the peripheral shoulder, each tab positioned under the peripheral shoulder being subjected to a force applied by said peripheral shoulder, said force causing a curved deformation of the section of the peripheral shoulder extending between the tabs positioned under the peripheral shoulder, the deformation of the locking tab disposed on said section allowing the spring ring to be locked in the attached position thereof. - a pivot module, - a support provided with a housing accommodating the pivot module, the support being surmounted by a peripheral shoulder extending from a rim of the housing towards the centre of the support, said peripheral shoulder comprising a plurality of recesses opening onto the housing with at least one of said recesses forming a so-called locking recess, - a spring ring able to adopt respectively a so-called mounting position and a so-called attachment position with respect to the support, said spring ring being arranged between the peripheral shoulder and the pivot module in order to exert an elastic force on said pivot module when the spring ring is in the attachment position, said spring ring being provided on the outer periphery thereof with a plurality of tabs with at least one of said tabs forming a so-called locking tab, the plurality of tabs extending radially away from the centre of the support and giving spring ring an outer diameter which exceeds the inner diameter of the peripheral shoulder, the plurality of tabs cooperating with the peripheral shoulder during the mounting and bayonet attachment of the spring ring to the support, the recesses of the support having dimensions at least equal to those of the tabs to allow the engagement of the tabs in the corresponding recesses during mounting, - the number of recesses is greater than the number of tabs with at least one extra recess forming the locking recess, - in the attachment position, one part of the tabs is positioned under the peripheral shoulder and another part comprising at least said locking tab is positioned in said locking recess, said locking recess being surrounded on each side by a tab positioned under the peripheral shoulder, each tab positioned under the peripheral shoulder being subjected to a force applied by said peripheral shoulder, said force causing a curved deformation of the section of the peripheral shoulder extending between the tabs positioned under the peripheral shoulder, the deformation of the locking tab disposed on said section allowing the spring ring to be locked in the attached position thereof.