METHOD OF EXPERIMENTAL-THEORETICAL DETERMINATION OF FRICTION PERFORMANCE OF FRICTION PAIR FOR TORQUE TRANSFER AND DEVICE FOR IMPLEMENTATION OF THIS METHOD

摘要

FIELD: machine building.;SUBSTANCE: tested friction pair is loaded by means of calibrated loads with torque facilitating its successive rotation in forward and reverse directions, then torques M₁ and M₂ occurring at gear rotation correspondingly in direct and reverse directions are recorded with instrument; by value of theses measurements there are evaluated friction losses in gear. Load (net) moment M_net is recorded when friction pair is idle. Moment M_r of resistance is calculated as half of difference of values between M₁ and M₂. Calculated functional dependence M_r=f(M_net) in form of two massifs of experimental values is approximated by the least-squares method with linear dependence M_r=f_fr M_net+M_i, where f_fr - is friction coefficient, M_i is moment of idle run of friction pair; M_i=F_eng·r, where F_eng is force of engagement, r is radius of friction pair. On base of obtained constants of the approximating function there is determined required functional characteristics f_fr and F_eng. The device consists of a unit-cable system with loading means in form of calibrated loads connected to it on one side, and with a drive mechanism and the recording instrument - a dynamo-metre or dynamo-graph - on another side. Further, the device consists of a frame whereon there is hinged a drive lever with a sector so, that movement of the lever is restricted with stops within boundaries of the sector. On a lower part of the sector there is secured one end of the cable going vertically to a drive pulley, enveloping it and going vertically down, when it touches a deviating unit connected to the recording instrument. On another end of the cable there are arranged the calibrating loads. The drive pulley is coupled with a shaft, on journals of which there are mounted the tested friction pairs of rotary motion; the latter are rigidly fixed on two supports secured on the frame by means of two split cases.;EFFECT: determination of friction characteristics in friction pairs for torque transfer.;4 cl, 6 dwg