Abstract
<jats:p>In the oil production industry, the operation of sucker-rod pumping units is widely applied, where the main component is the lathe manipulator. In these units, motion from the reducer shaft to the walking wheel is transmitted through a spline connection and a clamping device. This connection must be designed such that, under any operating load, no slippage occurs between the walking wheel and the shaft. Otherwise, the parallelism of the rods is disturbed, and the walking beam is subjected to additional loads. For reliable operation, the sum of the frictional moments generated by the spline connection and the clamp must exceed the torque on the output shaft of the reducer. One of the primary conditions for the optimality of the considered connection is the equality of the maximum pressures acting on the walking wheel from the upper, thickest surface of the spline (corresponding to the end face of the shaft) and on the contact surface of the reducer shaft. At the same time, these pressures must not exceed the allowable compressive stress for the walking wheel material, which ensures effective material utilization. Based on the continuity condition, a theoretical mathematical expression has been derived for determining the minimum force generated by the clamping screw, at which the compressive deformation at point B of the walking wheel equals the bending deformation at point under the applied forces. As an example, the calculation of the walking wheel connection of the CKD-8 lathe manipulator was carried out. It was found that the torque transmitted by the spline connection is 2.16 times lower than the torque transmitted by the clamping connection. To increase the load-bearing capacity of the spline connection, it is recommended to match the inclination of the keyway on the shaft with the inclination of the working surface of the spline. In this case, for the pressure acting on the contact surface of the spline and walking wheel, taking into account the non-uniform pressure distribution along the spline length, the coefficient can be used. During assembly, it is recommended to carefully monitor the force applied to seat the spline in the keyway. Keywords: Sucker-rod, pumping unit, gear reducer, output shaft, crank connection, keyed joint, clamping device, friction torque, load-bearing capacity, stress distribution.</jats:p>