FORECASTING THE RESOURCE OF TWO-DISC COULTERS OF GRAIN SEEDERS

The service life of the working bodies of soil-cultivating machines depends on the properties of the processed environment. The influence of soil moisture on the change in its physical state and wear capacity is analyzed. The factors of reduction and loss of performance of disc coulters of grain seeders are established. It is proposed to assess the performance of disc coulters by the coulter performance coefficient kрс. An analytical dependence of the kрс coefficient on the wear intensity in the "normal" and "wear" periods is obtained. At kрс=0.25, the ratio of the "normal" and "wear" periods is 1:3. At kрс=0.75, this ratio is 3:1. An original experimental setup was created and studies of prototypes on a loosely fixed abrasive were conducted. The highest wear resistance is demonstrated by the experimental samples made of ultra-high molecular weight polyethylene (UHMWPE) grade PE-1000, their relative wear is 0.29…0.44 compared to the sample made of 65G steel. Average wear rates for different operating conditions were determined by field tests of the modernized (MDS) and standard (SDS) disc coulters. They were 0.41 mm/ha and 0.25 mm/ha for the “normal” period and 1.92 mm/ha and 1.62 mm/ha for the “wear” period of operation for SDS and MDS, respectively. A nomogram has been developed for predicting the resource and monitoring the technical condition of double-disc coulters for different operating conditions. With the value of kрс=0.25, the predicted resource for SDS will be 11.1 ha, against 16.2 for MDS. The resource increase is 1.46 times. With the value of kрс=0.75, the predicted resource for SDS will be 23.1 ha, against 37.7 for MDS. The increase in the resource is 14.6 ha, which is 1.63 times more. The nomogram allows planning the implementation of repair and restoration operations taking into account the actual annual load of grain seeders.