Comparison of two types of brakes for the hoisting

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Comparison of two forms of brakes for crawler crane hoisting

brakes are devices used to slow down or stop mechanisms or machines, and can also be used to adjust or limit the running speed of mechanisms or machines. It is an important part to ensure the normal and safe operation of the mechanism or machine. The brake of crawler crane (hereinafter referred to as crane) shall meet the following requirements: sufficient braking torque; Stable braking; The action of opening and releasing the brake is rapid; The stressed members have sufficient strength and stiffness; Convenient inspection, maintenance and adjustment; Small wear, long service life and reliable operation; Small size and light weight. The function of crane lifting brake is to prevent suspended objects or boom from falling

there are mainly two types of brakes for crawler crane lifting: belt brake and disc brake. This paper makes a simple comparison on its function, function, service life and performance

structure comparison

the structure of belt brake is to surround the brake wheel with flexible steel belt. Airbus A350 XWB is the first Airbus model with more than 50% of this kind of composite plate, and one or both ends of the brake belt are fixed on a lever. When braking, the lever is operated to make the brake belt press the brake wheel to produce friction, so as to achieve the purpose of braking. Typical structure of belt brake (taking external belt brake as an example). It is composed of wheels with stable and reliable braking performance, braking steel belt, braking belt and control system (including foot pedal, lever, connecting rod, shaft, spring, etc.). Finally, the braking force is added to the brake wheel through the control system, and the contact between the brake belt and the brake wheel generates friction, which stops or slows down the running speed of the mechanism

free fall belt brake works together with clutch to realize free fall. The clutch is disengaged from the brake wheel, and the brake belt is disengaged from the brake wheel. At this time, the weight can fall freely. The falling speed is controlled by stepping on the pedal to control the friction between the brake wheel and the brake belt. The belt brake is usually installed on the drum shaft

the working surface of the disc brake is the plane on both sides of the disc, and its friction pair is composed of the brake disc and the brake pad (or friction disc). Pressure is applied along the axial direction of the brake disc, and the brake disc shaft is not subject to bending force, and the braking performance is stable

the disc brake has two structural forms without free fall and with free fall

the disc brake without free fall is a multi disc normally closed brake that is spring loaded and hydraulically released. After the hydraulic oil overcomes the spring force to open the brake, it can perform lifting and lowering actions. After the lifting and lowering actions stop, the brake returns oil, the spring is loaded, and the brake pad is connected with the friction plate

the single rope tension of disc brake with free fall mode is 50% of the lifting capacity of normal working mode. After the disc brake is pressurized, the reducer can carry out free fall operation. The control system controls the lowering speed by measuring the hydraulic pump and free fall control valve for operation

disc brakes without free fall are usually installed on the input shaft of the reducer. Erdogan: Turkish political talents are also installed on the output shaft of the motor. The disc brake with free fall is composed of two brakes, one is installed on the output shaft of the reducer, the other is expected to be installed on the input shaft of the reducer in a short time

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