Difficulties in the design of transmission drum of food transmission line equipment

Drive roller design has been a difficulty of food conveyor line manufacturers, combining with the characteristics of industry production of the new type roller, there is no universal design series formation, in addition to the typical cylinder shaft has a mature design, other cylinder parts, especially the stress and deformation of cylinder and the radial plate still has no authority to explain. The thickness of the driving drum and spoke plate is determined according to the diameter of the bearing part calculated.

In the actual design process of the transmission drum, if the stress value is too high, it is necessary to modify the structure size of the drum until it meets the requirements.

In addition to the torque input from the shaft end, the driving drum is also affected by the force input from the shaft end to the conveyor belt. Food conveyor belt tension ratio can only be small, otherwise there will be skid phenomenon. In practice, it refers to the situation that all the wrapping arcs used for force transmission are not fully utilized, so there should be the so-called wrapping Angle using arc. The rest of the wrapping Angle is the rest arc. The rest arc represents a reserve of the circumferential force, which is used to overcome the resistance at startup or the previously unestimated resistance, or to prevent the conveyor belt from slipping when the friction coefficient decreases.

Generally, the stationary arc occurs when the food conveyor line runs stably. If the rest arc disappears, there will be a maximum difference, and all envelope angles will be transferred by force. This situation often occurs when the belt food transmission line is started. Set the conveyor belt on the drum wrapping Angle of 180 degrees, so as to produce tension difference at both ends of the conveyor belt. The torque produced by this difference is equal to the torque applied to the drum shaft. In the utilization arc, there is friction between the conveyor belt and the roller, and the tension of the conveyor belt increases gradually. The conveyor belt tension is constant in the static arc, and the running speed of the conveyor belt is consistent with the circumferential speed of the roller. There is no sliding between the conveyor belt and the roller in this arc. That is, when the conveyor belt tension is constant from one endpoint to the other. In order to better check the strength of the drum, if the drum is running at full load, there is no static arc of the conveyor belt tension on the drum, friction exists in the whole envelope Angle range, and the structural support of the drum has been aligned, so there is no load concentration phenomenon.

The maximum displacement of the food transmission line drum appears on the coordinate point, that is, in the center of the drum shell near the outer surface of the drum at the driving end, and the maximum value is 0.06 mm. The stress of the driving drum mainly concentrates on the shoulder of the shaft and the bearing, the connection between the expansion sleeve and the hub, the connection between the hub and the spoke plate and the surface of the drum. The maximum equivalent stress at the point, namely the shaft and bearing connection inside, the maximum equivalent stress, according to the strength theory of the maximum equivalent stress, allowable stress of the material, the transmission drum shaft, using 45 steel quenching and tempering treatment, obviously, the transmission drum shaft meets the strength requirements, the whole transmission drum can also meet the strength requirements.

However, the strength margin is large, and the deformation is small, so it can be seen that the safety factor is large, which should be optimized and modified to meet the strength requirements and save materials. Although the maximum stress does not appear in the shell of the drum, but because there is a weld in the area, and the quality of the weld directly affects the service life of the drum, so the manufacturing of the food delivery line transmission drum should be more strict, the reliability is not significantly improved, but not directly in the danger point and stress state of the drum.