The paper provides the study and substantiation of the parameters of semi-hitched spindle cotton harvesters during one-time cotton-picking. A calculation scheme for the spindle interaction with an open cotton boll in the “cylinder-deformable ball” form was proposed. A mathematical model to change the distance between oppositely located spindle drums in the working chamber and a method to calculate the indentation of the boll contact on the spindle of a vertical-spindle picking apparatus were obtained. The model made it possible to calculate the rational technological parameters of the device and machine. Kinematic functioning parameters of vertical-and horizontal-spindle picking devices were specified, taking into account their installation on a semi-hitched cotton harvester. The obtained data were used to create machines for a one-time cotton-picking.

Weather conditions in the risky cotton growing area largely determine readiness of the agricultural background of the cotton field for machine harvesting of cotton. A combined cotton picker with replaceable horizontal spindle and vertical spindle devices was invented. At full (85-90%) opening of cotton bolls, an option of a cotton picker with horizontal spindle is applied, and at incomplete (55-60%) opening – an option with vertical spindle devices is applied. Field trials of a cotton picker with removable devices were carried out. The estimated parameters were completeness of cotton harvest, residue on bushes, losses to the ground, debris and moisture of harvested cotton. Use of a combined cotton picker allows to harvest cotton selectively at full and incomplete opening cotton bolls. Productivity and cotton-picking quality has increased.

The article presents the methods for calculating the pressure loss of the pneumatic transport system of a cotton harvester related to the power consumption of the fan drive. Mathematical models for computer calculation are presented. Numerical studies of the influence of the pipeline diameter and the air mixture composition on the power consumption of the fan drive are presented. It was determined that with an increase in the diameter of the pipeline from 0.15 m to 0.175 m and a change in the mixture concentration μ = 0.228 ÷ 0.338 for a serial receiving chamber, the fan drive power decreases from 10.3 kW to 5.79 kW.

This article provides a versatile suction air intake chamber for vertical and horizontal spindle cotton pickers. The results of field tests using the new universal receiving chambers are presented. The results of field tests showed that the use of the new universal intake chambers reduced the power loss on the fan drive by 1.8 … 2 times compared to the Case-2022 horizontal spindle machine. For the MX-1.8 vertical cotton picker, the weediness of raw cotton was reduced by 1.0-3.0% and crushed seeds by 1.35 times compared to serial receiving chambers.

The article considers the possibility of reducing the degree of impurityof machine-picked raw cotton. An analysis of the main factors influencing the cotton impurity was conducted. It was established that, to a large extent, raw cotton is clogged in the receiving chamber, where it is transported from the working apparatus. A new design of U-shaped receiving chamber was developed and tested. The results of field and theoretical studies are presented. A mathematical model is proposed for the computational-empirical determination of the degree of impurity of raw cotton harvested by machines. The new U-shaped receiving chamber has improved the quality of machine harvesting of raw cotton by reducing its impurity. Deviations of experimental and calculated data do not exceed 4-9%.