Now NGW type planetary gear transmission, for example, as shown. To simplify the calculation, select the representative pitch at the calculation point of the film thickness. NGW type (1) The equivalent radius of curvature RR = R2R1 (R2R1) (2) of R1 and R2 are the radius of curvature of the mesh at the tooth surface. Pitch at the radius of curvature R1 = r1sini; R2 = r2sinir1 r1cosi; r2 = r2coscosi type r1, r2, gear pitch circle radius; r1, r2, gear pitch circle radius; gear pressure angle; i two gears meshing angle.
+-Generation into the type (2) have the R = 05mz2z1costan1 (z2z1) (3) style (3) applies to the center wheel a and planets round b of the outer mesh, – signs apply to planet b and center wheel c\\ s within the mesh.
(2) 2 type of lubricant entrainment velocity uu = (u1 + u2) in the u1, u2 two round at the entrainment velocity; u1 = nH1r1sini30u2 = nH2r2sini30nH1, nH2 two gears in the transformation of institutions speed.
Because nH1 = nH-n1 = nHz2z1, so the load W3W u = mz2nHcostani30 (4) (3) unit contact width is not only the tooth width B, but also consider the gear to the coincidence degree of its impact. W = FtBcos = 2T1diim2z21cos (5) Ft gear to pass the circumference force; T1 pinion transmission torque; i overlap coefficient, that is, the degree of coincidence rounded; di tooth width coefficient.
(4) the minimum film thickness hmin will type (3), type (4) and type (5) generation into the type (1), may have minimum film thickness hmin = 03704054E-003 (0nH) 07m139z0691 (cos) 126 (z2tani) 113 (z2z1)-043T-0131 (dii) 013 (6) 2 lubrication state of the lubrication state of wear of tooth surfaces not only depends on film thickness, but also by the influence of tooth surface roughness. Usually the film thickness ratio as a criterion = hminR2q1 + R2q2 (7) type in Rq1 the Rq2 two tooth surface contours of the root mean square deviation.
Is generally believed that, when <1, two tooth surface in the boundary lubrication; when = 13, two of the tooth surface in the state of partial elastohydrodynamic lubrication;> 3:00, that the tooth surface will not produce wear. Is generally believed that the two tooth surface in the boundary lubrication condition, the tooth surface will result in wear and tear; two tooth surface in the state of partial elastohydrodynamic lubrication, the tooth surface may produce wear and tear; two tooth surface is completely elastohydrodynamic lubrication condition, the tooth surface will not produce wear .
Instance SGZ8802400 face scraper conveyor gear in the machine for two involute planetary gear transmission, as shown. Known, high-speed stage planetary gear drive gear material 18Cr2Ni4WA steel, the input power P = 400kW input speed n1 = 1470rmin The modulus m = 7mm, pressure angle = 20%, outside the meshing gears meshing angle 1 = 235% internal meshing gears meshing angle = 185%, the transmission ratio i = 7.5, the number of teeth of the gear z1 = 16, z2 44, z3 = 104, planetary gear number k = 3, tooth width B, = 80mm, selected No. 220 industrial gear oils, try to determine the status of high-speed stage planetary gear drive lubrication.
Scraper conveyor drive unit (1) according to the material of lubricants and gear pairs = 130 510-5m2N; 0 = 0198Nsm2E = 231011Nm2 (2) parameter calculation load coefficient of uniformity of Kc = 1.1 tooth width coefficient d1 = Bd1 = 80112 = 0714d2 = Bd2 = 80308 = 0260 torque T1 = 9550KcP (kn1) = 9528102NmT2 = 9550KcPz2 (kn1z1) = 2620103Nm (3) the minimum film thickness of each parameter were substituted into equation (6) obtained the minimum film thickness of the gear pair hmin1 = 03704054E-003 (0nH) 07m139z0691 (cos) 126 (z2tan1) 113 (z1 + z2)-043T-0131 (d11) 013 = 2129mhmin2 = 03704054E-003 (0nH) 07m139z0692 (cos) 126 (z3tan2) 113 (z3- z2)-043T-0132 (d22) 013 = 2885m (4) lubrication condition and wear the gear hobbing or shaper processing, the tooth surface roughness value of Rai, = 16m, Rqi = 20m, then use (7) calculate the film thickness ratio of 1 = 0753 <1,2 = 102> 1, so the center round a planetary gear b between the two tooth surfaces in boundary lubrication, the tooth surface will result in wear and tear; and the planetary gear (b) and center round of c in the state of partial elastohydrodynamic lubrication between the two tooth surfaces, the tooth surface may produce wear and tear.
The gear tooth grinding machining and shaving processing, the tooth surface roughness values taken Rai, = 04m, Rqi = 05m (7) calculate the film thickness ratio = 301> = 408> 3, so two pairs of gear tooth surface is fully elastohydrodynamic lubrication state, the tooth surface will not wear.
Planetary gear drive with the degree of wear of the tooth surface and its conclusion scraper conveyor in which the lubrication state is closely related to the planetary gear drive in the machine of film thickness and film thickness ratio calculated by the scraper conveyor, can determine the lubrication of the transmission status and whether to produce wear and tear, the design of the transmission parameters, the choice of lubricants and gear pair materials and process to determine a practical guide for the scraper conveyor, planetary gear drive wear-resistant design provides the necessary theoretical basis.








