Lifting Mechanism with Ribbon Brake

摘要

The scheme of a typical lifting mechanism of the load lifting machine is considered. Its disadvantage due to the placement of the brake pulley on the coupling half located on the high-speed shaft of the reducer is indicated. This deter-mines the rationality of installing the brake directly on the working mechanism of the lifting machine mechanism. The installation of the shoe brake directly on the working element is irrational for design reasons. Therefore, it is suggested to use a ribbon brake. The main drawback of ribbon brakes is the impossibility of predicting failures, caused by the single-element steel tape which is the brake actuating element. Therefore, it was proposed to use as polyurethane ribbon reinforced with steel multi-wire ropes, which acts as an actuating element of the brake. The theoretical foundations of a ribbon brake design are considered and the main design dependencies that can be used in this case are given. The known schemes of ribbon brakes are listed, and it is suggested to use a differential ribbon brake in the lifting mechanism, in which the ends of the ribbon are attached directly to the brake lever on opposite sides of the axis of its rotation. The design scheme of a differential ribbon brake is given and conditions which should be fulfilled at its designing are given. The design of the crane lifting mechanism equipped with a differential ribbon brake installed directly on the cargo drum is presented. The construction of the differential ribbon brake is given. The fastening of the ribbon ends to the axes of the lever is proposed to be carried out with the help of wedge clamps. The brake was calculated with the use of a specially designed computer program.