Production Workshop Bridge Crane Notice 2

Continuing from the previous article "Production Workshop Bridge Crane Notice 1", in addition to paying attention to the safe use of hooks, wire ropes, drums and wire rope pressure plates, workshop bridge cranes also need to pay attention to reducer gears, brakes, wheels and tracks and Safety accessories and other four aspects that cause mechanical failure:

 

 

4. Reducer gear

 

(1) Failure analysis

 

The reducer is an important transmission part of the 25 ton bridge crane. The torque is transmitted through the meshing of the gears, and the high-speed operation of the motor is adjusted to the required speed. Mechanical failures such as wear and tooth surface wear, the causes of gear failures are as follows:

 

① Fatigue fracture caused by short-term overload or impact load, repeated bending;

 

② The tooth surface is not smooth, there are raised points to generate stress concentration, or the lubricant is not clean;

 

③Lubrication failure due to high temperature;

 

④ Abrasion is caused by hard particles entering the friction surface.

 

(2) Preventive measures

 

① The crane cannot be used for loading, and the start and brake should be slow and stable. It is forbidden to reverse the car suddenly under non-specific circumstances;

 

② Replace the lubricant in time, and clean the shell, and choose the appropriate type of lubricant;

 

③ Always check whether the lubricating oil is clean; if the lubricating oil is not clean, replace it in time.

 

5. Brake

 

 

(1) Failure analysis

 

The brake is an important safety component of the bridge crane. It has the functions of preventing the hanging objects from falling and realizing parking. Only a good brake can guarantee the accuracy and safe production of the crane. During the operation of the crane, the brake will have insufficient braking force, The brake suddenly fails, the temperature of the brake wheel is too high, the brake pad smokes, the brake arm cannot be opened and other mechanical failures.

 

The reasons for these mechanical failures are analyzed as follows:

 

① Excessive wear of the brake band or brake wheel;

 

Partial detachment of small pieces of brake tape;

 

The main spring is adjusted too loosely;

 

There is oil dirt between the brake band and the brake wheel;

 

There are stuck places or excessively worn parts outside the living hinge;

 

The lock nut is loose and the whole tie rod is loose;

 

The impeller rotation of the hydraulic push rod brake release is not flexible;

 

② The brake pads are severe or a large piece falls off, or the long-stroke electromagnet is stuck, the main spring fails, or the main parts of the brake are damaged;

 

③ The gap between the brake and the gasket is adjusted too large or too small;

 

④ The hinge is stuck or the braking torque is adjusted too large, or the oil cylinder of the hydraulic push rod brake release is short of oil and mixed with air, or the grease used for the hydraulic push rod brake release does not meet the requirements, or the brake pads are not compatible with the brake pads. There is dirt between the brake wheels.

 

(2) Preventive measures

 

Regularly check and maintain the brakes. The brakes of the lifting mechanism must be once a shift, and the brakes of the operating mechanism must be once a day. The main inspections are as follows:

 

① Whether there is any stagnation and wear at the hinge, and whether there is any looseness at each fastening point;

 

② Whether the action of each movable part is normal;

 

③ Whether the hydraulic system is normal;

 

④ Whether the wear between the brake wheel and the brake band is normal and whether it is clean.

 

Determine whether the brake is normal according to the inspection situation, resolutely put an end to running with disease, and regularly lubricate and maintain the brake.

In order to ensure the safe operation of the crane, the brake must be adjusted frequently to ensure the working requirements of the corresponding mechanism.

 

6. Wheels and tracks

 

During the operation of the crane, the common faults of the wheel and the track are the gnawing of the wheel and the unequal height and slipping of the trolley.

 

Among them, there are many reasons for gnawing, and the forms of gnawing are various. If the gnawing road is light, it will affect the life of the crane, and if it is heavy, it will cause serious casualties. Therefore, special equipment managers should pay enough attention to the gnawing road.

 

The main reason for the gnawing road is that the installation does not meet the required error, uneven friction, excessive wear of parts in the transmission system of the cart, and excessive key connection clearance, resulting in asynchronous braking.

 

Therefore, the special equipment authorities of each unit must find a qualified unit for installation and maintenance when installing and maintaining cranes, so as to ensure equipment safety and operating life;

 

At the same time, the special equipment management personnel should strengthen the usual inspection and management to avoid the mechanical failure of the crane from gnawing the road. During the inspection process, they must carefully and carefully find out the cause of the gnawing road and take corresponding measures.

 

The unequal height of the wheels of the trolley is an extremely unsafe factor in the operation of the crane. The unequal height of the trolley makes one wheel suspended in the air or the wheel pressure is too small during the operation of the trolley, which may cause the vibration of the trolley body.

 

The factors causing the unequal height of the trolley wheels are caused by many reasons, but the main reason is that the installation error does not meet the requirements and the weight of the trolley design itself is uneven. High problem solved.

 

During the operation of the crane, due to the unclean track, excessive starting, uneven track of the trolley, ellipse of the wheels, and unequal wheel pressure between the driving wheels, the trolley has a slipping ring phenomenon, which requires special equipment management personnel to check during the inspection process. You must be careful and careful during the operation, and solve the problems in time to avoid the phenomenon of trolley slipping.

 

7. Safety accessories

 

The safety accessories of bridge cranes are completely protective devices set up from the perspective of protecting equipment and operators. The management of safety accessories must follow the requirements of the "Special Equipment

 

Safety Supervision Regulations" to strengthen the management and supervision of safety accessories to ensure safety. The accessories are in good condition to ensure the safe operation of the overhead crane.

 

The mechanical failure of bridge cranes is relatively complicated. To prevent mechanical failure, it is necessary to strengthen equipment management. At the same time, it is necessary to submit an annual review application to the local special equipment management and supervision department on time, and eliminate the unsafe factors of the equipment through the inspection and guidance of the special equipment supervision department. In the bud, so as to ensure the safety of equipment and personnel.