Reducing grain harvest losses is a primary goal of farmers and implicitly the manufacturers of self-propelled combine harvesters. The combine harvester is destined for grains harvesting of cereals, performs at the same times: the reaping, the threshing, the cleaning of the grains and their collection in an own grain tank. The reaping of the plants consists of cutting them and transporting them to the threshing drum. During the cutting the plants must be supported and directed to the header auger, an operation carried out by the reel. Taking into account the varying conditions that occur at harvest, the reel from the header should be designed so that the losses at harvest are minimal. The reel that best meets this condition is the eccentric reel or the universal reel. For these reasons we have chosen to study a universal reel fitted to the harvest header from the self-propelled combine John Deere S series. The working organs of the reel are elastic fingers from steel or plastic. In order to perform a correct harvesting both the angular velocity and the position of the reel must be within certain parameters so that the elastic fingers bend the plants back so that after cutting they are placed on the header auger. The constructive and functional parameters of the universal reel studied were: the reel diameter, the reel length, the angular velocity of the reel, the elastic finger trajectory, the tangential speed of elastic fingers, the acceleration of elastic fingers, the kinematic index of the reel. In the case of absolute movement, when the reel is rotating and at the same time moving with the working speed of the combine harvester, the trajectory of the elastic fingers of the reel is a cycloid. The kinematic parameters of the reel were determined by the analytical method according to its constructive and functional parameters. The calculations were made for two complete rotations of the reel. Based on the obtained results, the functional parameters of the reel were determined: the length of the cycloid, the time of a complete rotation of the reel and the area covered by the reel to a full rotation. Following the studies carried out, the conclusions and recommendations that are required are established

harvest header, reel, elastic fingers, trajectory, speed, acceleration

sciences soil

Presentation: oral