Scheme for determining the coefficient of friction is shown in Fig. 20.
On the platform 1 of a pilot plant with WHD-2 shaft 2 is mounted rotatably and base 3 dynamometer. On the shaft 2 is located in gear 4, which rotates with the shaft (the direction of rotation indicated by arrow 5). The base 3 by means of ball bearings 6 are connected with a rack 7. At the reception 7at a distance of «L2» from node 6 is rolling metal support 8, which is a free end vertically supported by a gear 1 at a distance of «L3» from the axis of the shaft 2. On Prop 8 is fixed load 9. At the junction of the rack 6 with 7 pillar mounted load cell 10 at an angle of 90 degrees to the bar 7 and 8 support.
Determination of the coefficient of friction «f» in the following manner. On Prop 8 is fixed such goods "Prp", which enables stable rotation of the shaft 2 with the gear 4. At the same time are putting such an effort "Ftr" to a dynamometer, which will prevent the movement of rack 8 in the horizontal direction.
Coefficient of friction f = Pf / Pn, (19)
f - coefficient of friction obtained experimentally under braking gear under consideration by the application of tangential force equal to the friction force Pf, the point of application of the normal pressure Pn;
Pf = 0.28 kg - the friction that occurs as a result of the interaction (friction) metal supports 8 and 9 with a cargo rotating gear 4 and the measured dynamometer 10;
Pn - the normal pressure at the point of application of force "P" on the surface of the gears in the determination of the coefficient of friction «f», kg
Pn = Pw + Pst (20)
where Pw = 1 kg. - weight of the load 9, mounted on a support 8;
Pst = 0.4 kg. - Tte static weight of the movable part of the chassis dynamometer
Pn = 1 kg + 0.4 kg = 1.4 kg.
Coefficient of friction f = 0,28 kg / 1.4 kg = 0.2