FIELD: machine building.
SUBSTANCE: invention relates to machine building, to methods for determining coefficient of friction in thread. A chain of parts is assembled to create load F stretching the bolt rod and to maintain the value of this load approximately constant during rotation of the bolt rod. This chain of parts includes a tension spring, a cable and swivels, which enable to rotate the bolt rod with low friction forces, a set of discs having narrow annular zones of different geometrical sizes with a coating having the same friction coefficient for all discs is also included. At that, the value of friction coefficient between adjacent disks is known, these disks are put on a tube, these discs, when they are not pressed to each other, can freely, i.e. with low friction forces, rotate relative to its axis of symmetry, in this set the disks are arranged so that the moment of friction forces between adjacent disks successively decreases. These discs are pressed to each other by a force equal to the tensile force of the bolt rod; at that, near the nut there is a disc attached to the nut. If at the rightmost boundary between the discs the frictional moment is less than the frictional moment in the thread, then during the threaded rod rotation the nut will be fixed relative to the threaded rod. Wherein the disks slide relative to each other. Discs are locked from turning each other at this boundary and torque is applied to threaded rod again. If the nut again remains fixed relative to the threaded rod and "slippage" is observed in the zone of the boundary of the discs, then these discs are locked and a torque is applied to the threaded rod again. And so on until the nut starts to rotate relative to the threaded rod. After estimating the value of frictional forces in the thread, estimates of the value of the friction coefficient are obtained based on the calculations.
EFFECT: providing the possibility of conducting research on determining coefficient of friction in thread for objects without two support surfaces.
1 cl, 2 dwg, 3 tbl
