Jiaozuo brake

The electric hydraulic block brake of the crane is usually normally closed

The brake commonly used in cranes belongs to the normally closed type, and if users require a normally open type, they need to be notified separately before ordering. The body of the crane crane crane is very heavy and has a lot of inertia during operation. When the crane is in normal operation, it immediately reverses and brakes sharply, which will generate a large amount of torque in the entire operating mechanism and damage the transmission system. In severe cases, it may cause the transmission shaft to twist and break, and may also cause the vehicle body to twist and deform; Reverse emergency braking can also cause severe impact on the gear connection system, damage the gears, and cause equipment accidents; Reverse braking can also cause the electric dynamometer to generate a large amount of torque and strong current, which can seriously burn out the motor. The band brake is a normally open type, mainly relying on the friction between the brake wheel and the brake band wrapped on its surface to generate braking torque. When braking, it generates a large radial load on the shaft, resulting in uneven wear of the brake band. If the braking part is on the output shaft of the reducer, the braking device will be quite bulky.

The electromagnetic block brake belongs to the normally closed type, which relies on the brake pads connected to the fixed bracket to compress the brake wheels on the transmission shaft, and the braking torque is generated by the friction force between the brake pads and the brake wheels. It controls the release and holding of the brake through the attraction and release of the electromagnet. Due to the power outage of the electromagnet, the suction suddenly disappears. The sudden application of force by the compression spring can cause severe braking on the mechanism, causing mechanical vibration of the transmission mechanism. Additionally, the lifespan of the electromagnet is very short and requires frequent maintenance or replacement. When the electromagnet is not tightly engaged, there is a risk of burning the coil. Its allowable number of joints per hour is relatively low, generally<300/h. In addition, when the load descends, with the permission of the safety barrier, the descent speed is affected, which is not conducive to improving efficiency and saving energy http://www.jzszdq.com

Reverse emergency braking can also cause the suspended object in the air to swing and cause the object to fall. Therefore, in work, except in special dangerous situations to avoid accidents, reverse emergency braking is not allowed.

Relevant personnel should carefully inspect the reliability of hooks, wire ropes, brakes, and safety protection devices, and report any abnormal situations in a timely manner.

Secondly, before starting the operation, the following conditions should be confirmed to be in a safe state before starting the machine:

(1) Are all controllers set to zero;

(2) Are there any unrelated personnel on the crane and in the operating area, and whether the operating personnel have been evacuated to a safe area;

(3) Are there any obstacles that have not been cleared within the operating range of the crane;

(4) Is the small distance between the crane and other equipment or fixed buildings at least 0.5m;

(5) Is the power circuit breaker locked or equipped with warning signs;

(6) Whether the site of the Mobile crane is leveled and the outriggers are firmly and reliably laid as required.

Thirdly, before driving, it is necessary to ring the bell or warn; When approaching people during operation, intermittent ringtones or warnings should be given.

Fourthly, drivers are not allowed to engage in the following behaviors during normal operation:

(1) Parking with permission locators;

(2) Using reverse braking for braking;

(3) Conduct inspections and repairs during lifting operations;

(4) Adjust the brakes of the lifting and luffing mechanisms with load, or increase the operating range with load;

(5) Suspended objects shall not pass through the top of a person's head, and no person shall stand under the suspended object and lifting arm.

Fifth, strictly follow the command signal operation, and for emergency stop signals, no matter who sends them, they must be immediately executed.

Sixth, when the lifting load is close to or reaches the rated value, or when lifting dangerous goods (liquid metals, harmful substances, flammable and explosive materials), carefully check the brake before lifting, and use a small height and short stroke test lift to confirm that there are no problems before lifting.

Seventh, the small distance between each part of the crane, lifting load, and auxiliary equipment and the transmission line should meet safety requirements;