Causes and preventive measures for the burning of vibrating
Vibration motor is the power source and vibration source combined excitation, vibration sieve machine at each end of the rotor shaft to install a set of adjustable eccentric block, eccentric angle adjustment can be obtained by different forms of vibration, using centrifugal force high-speed rotating shaft and the eccentric block generated by the exciting force, driving equipment through the motor or anchor flange。 The phenomenon of motor burning often occurs during the operation of the vibrating screen。 What are the reasons for this phenomenon? How to prevent it effectively?
1。 anchor bolt loosening motor destroyed
This is one of the main fault caused by vibration motor burned, vibration motor due to its special structure, the eccentric block at the two ends of the vibration force generated in the motor drive, the impact force of the anchor bolt can reach hundreds of times per minute, or even thousands of times, the exciting force of the huge role, easily the motor caused by anchor bolts loosening, a bolt loosening will soon cause other bolt looseness, if not in time, will cause the anchor bolt fracture, the motor burned.
(1) using high strength bolts, the strength of the foot installation or flange installation bolts should not be less than 8.8.
(2) at the beginning of the operation, the anchor bolts should be tightened for many times.
(3) to increase the anti loosening device, each nut must be added with an elastic washer. When necessary, double nuts are used to fasten it.
The motor base and foot to keep good contact, all anchor bolts keep uniform stress。
In the selection of vibration motor of the housing should pay special attention to the foot in some vibration motor shell (the shell, one seat) in the processing, can guarantee the shell and foot is one, the whole motor level can also be ensured, so that the motor is not easy in installation caused by foot bolt loosening。
There are some vibration motor with shell surface anchor together, because the foot is fixed due to subsequent installation, assembly error and easy to produce, leading to the foot in a horizontal plane, in the use of the process will be because of the uneven stress caused by loose bolts, if not timely discovery will lead to bolt fracture and burn the motor。
2. installation problem motor burned
When installing the vibrating motor, it must be strong and reliable. When the two vibratory motors need to be installed symmetrically, the positions of the two vibrating motors must be completely symmetrical on both sides of the equipment, and at the same time, the resonance of the equipment should be avoided.
Because the two ends of the vibratory motor are equipped with eccentric blocks for adjusting the amplitude, when the field needs to be tilted or vertically installed, the bearing of the motor must bear all or part of the gravity of the eccentric block.
If a special device such as a plane bearing is not protected in a vibrating motor, it will cause great damage to the bearing for a long time, thus shortening the service life of the motor。
(1) vibration machinery requires no blockage. The support points should be linked by springs, connected with other devices by soft connection, and no hard contact with external environment and equipment.
(2) try to avoid vertical or sloping installation。
(3) select a vertical vibrating motor with a plane bearing inside。
3。 eccentric block adjustment of unsymmetrical motor
The vibration motor is made up of four fan-shaped eccentric blocks as the excitation block. The two ends of the motor are composed of two blocks, and the required exciting force from zero to maximum can be realized by adjusting the angle between the two eccentric blocks of the vibrating motor.
When adjusting the eccentric block, if the direction of the two ends is reversed, it will form a large space torque inside the vibrating motor. If the motor runs in a long time with large torque, the motor will burn out. Therefore, the adjustment of the eccentric block must make the angle of the eccentric block at both ends of the motor consistent, and can not become a surface state, so that the 22 corresponding and mutual symmetry.
At the same time, the bolts to fix the eccentric block should be tightened and the spring card should be worn well。 There are two vibration motors around the general vibrating screen, which requires that the phase sequence of the motor should be corresponding, and the motor can not run in phase。
In strict accordance with the rules of installation, use and maintenance of vibrating motors, we can better play the role of vibration motors and prevent burning accidents caused by asymmetric adjustment of eccentric blocks。
4. shields are sealed with tight motor
In the actual work because of the vibration of the motor working environment is very poor, large dust protection, if the two ends of the motor cover and the motor gap between the larger, while the dust can easily enter the two ends of the motor, causing friction between the eccentric movement, this movement will produce a large amount of friction heat is accumulated to a certain extent in the heat。 The motor will be burned。
Therefore, in the bad working environment, one is to do the best to seal the protective cover of the motor, two to keep the cleaning in the protective cover, and to clean up the ash regularly.
5. ambient temperature motor burned down
In the work of the vibrating motor, if the medium temperature transportation equipments is too high, and the vibration of the motor is rigidly connected to the device together, due to thermal conduction properties of the metal, and the shell vibration motor temperature will increase rapidly in the limited space; when the heat dissipation is poor, it will cause local motor overheating.
(1) to reduce the temperature of the material。
(2) strengthening ventilation and cooling, reducing ambient temperature;
(3) on the premise of ensuring the normal work of the equipment, the motor can be kept away from the material of high temperature medium as far as possible.
6。 bad heat dissipation motor destroyed
General Motors generally have built-in cooling device, usually equipped with a fan in the end, when the fan rotates, the wind along the plurality of vertical reinforcement flow on the casing, one can quickly take away the heat generated by the motor, two can blow the dust away on the casing, the motor is always good working conditions.
Due to the limited structure, the vibration motor can't install fan cooling. When the motor surface has too much dust accumulation, it will hinder the heat emission, resulting in the motor's internal temperature rising too fast and burning the motor.
(1) when designing the motor, we should consider that the surface should be as smooth as possible. Otherwise, when the dust on the surface of the motor's heat dissipating bars is gathered to a certain degree, it will cause the heat dissipation of the motor to fail. At this time, we should consider reducing or even removing the heat dissipation bars on the surface.
(2) Remove the dust from the surface of the motor and make it work in good condition.
7. electrical wiring is not standardized for motor burn down
The cable of a vibrating motor must bear the vibration of the motor. Due to the influence of stress, the cable will fall off, the motor will run out of phase, and the motor's single-phase current will rise, which will cause the motor to burn down.
According to the electrical wiring wiring specification, selection of cable general heavy four core RV cable, wiring requirement of solid, near the cable outlet does not allow a sudden bend, motor three-phase outlet of uniform length, there is a natural drape shall be between the fixed junction box and cable card in no vibration, no stress phenomenon。 The cable should be fixed, and the motor junction box should be closed。
8. motor bearing wear motor burn down
Vibration motor, as a vibration source, will inevitably cause the vibration of motor. Motor bearings are subjected to high speed rotation force and vibration force, resulting in the increase of clearance caused by bearing shifting, and rolling body wear, resulting in bearing damage and clamping.
Preventive measures: regular replenishment of oil, sealing oil mouth to seal.
The burn out fault of vibrating screen motor is a common problem in production. We must strictly operate, maintain and maintain according to the requirements, and find out hidden danger in daily maintenance, and deal with it in time. Only careful operation and careful maintenance can ensure the long-term stable operation of the equipment.