To the Yantan power plant vertical into the water tanker brake mode, for example, its deck weight 1430t, weight concrete weight 1100t, the main lift brake type for the hydraulic disc brakes, including the working brake and safety brake two sets of systems The The shipper every time the need for action, the safety brake first open gate, open the gate in place after the main lift motor output to a certain torque after the work brake open gate, the lift machine began to run; need to stop, the working brake with the main lift motor first Closing brake, delay 6s after the safety brake closing brake, complete the operation process. Failure and accident, but also in accordance with the preparation of the brake action procedures, safe and emergency braking shutdown. The whole process of reliable and safe, in the installation and commissioning of the ship and the operation of the past few years to be a reliable verification. Therefore, if the crane uses the following braking method, you can achieve safe and reliable results.
3.1 The use of hydraulic disc brakes
Compared with the hub brakes, hydraulic disc brakes with a simple and reliable principle of braking, closing fast response and so on. In the closing brake, the brake shoe on the brake disc force is axial rather than radial, so that the impact of the brake disc is very small, so that the probability of failure to minimize the brake failure.
3.2 increase the safety brake
The safety brakes to be added here refer to the brake settings of the vertical shiplift, the addition of the brake discs in the reel and the array of disc brakes in the appropriate position to make them a fully independent set of safety brakes system. The advantage of doing so is obvious.
(1) the liberation of the manpower operation of the guardians, to reduce the risk of injury;
(2) to enhance the safety and reliability of the crane operation, when the crane accident can effectively prevent the expansion of the accident. If the crane, the drive shaft, the working brake, and the gear box are damaged, the safety brake of the reel part can effectively close the brake and stop the crane. Hooks continue to decline to prevent further expansion of the accident;
(3) In some special bridge cranes that need to be mechanically switched from gearboxes, simply press the safety brakes to ensure that the reel is tightened by the safety brakes and do the appropriate safety precautions Misoperation measures, you can as needed, release the working brake for high-speed and low-speed file exchange work.
3.3 Requirements for control systems
Taking into account the crane movements need frequent action, and a little action requirements, if the safety brake is also frequent action, it will affect the movements of the action requirements, therefore, the control system design should meet the following requirements of the working state:
(1) normal working condition. Each time the crane is started, the crane driver presses the start button, the safety brake automatically opens the gate, and the signal is opened to the console to allow the crane to work. During the crane operation, the lifting brake is completed by the working brake, the safety brake to keep the normally open state. Lifting the work of the end of the work brake closing brake, the crane driver to check the same, before leaving the console, cut off the crane power supply, safety brake closing lock, the end of the work;
(2) the working state of the crane when the failure occurred. In the event of failure, the crane driver presses the emergency brake button, the working brake closes the brake immediately, and the safety brake is delayed by 2 ~ 5s to stop the accident.
(3) the working state of the crane when the accident occurred. In the event of an accident, the crane driver presses the emergency brake button, the crane controls the power supply to disconnect, the working brake and the safety brake are immediately shut off the brake, preventing the occurrence of the accident;
(4) In special cases (such as a sudden failure of the crane system), the working brake and the safety brake shall also be subjected to an emergency closing brake at the same time.
Or the safety brake is set to normally open safety brake, usually the safety brake is always fully open state, the crane lift brake work by the work of the brake to complete the safety brake as a protective backup. When the crane fails and the accident or work brake needs to be repaired, the working brake needs to be released to switch the high gear and low gear when the safety brake is put into use.