Centrifugal fan coupling selection requirements and reference factors

Centrifugal fan's main power source is the motor, in many cases, will choose the coupling transmission and connection to connect the fan and motor, but as a rigid connection, not all kinds of couplings can be used as a centrifugal fan transmission, the following for you to organize the selection of centrifugal fan coupling requirements as well as the main reference factors for your reference.

A centrifugal fan coupling selection requirements

In the choice of coupling, we should consider whether the mechanical properties of the coupling can reasonably meet the requirements of centrifugal fan power, load capacity, power factor, etc., of which the load capacity is an important indicator of selection. Centrifugal fan coupling can withstand the main load: the torque transmitted by the impeller, the amplitude of the vibration of the motor itself, the gravity of the coupling itself, the center of mass or inertia of the coupling spindle due to a variety of reasons and its axis of rotation does not overlap, but also in the process of operation will produce unbalanced centrifugal inertia, centrifugal inertial moment force and other forces or moments, which directly affects the operation of the coupling.

Centrifugal fan shaft belongs to the transmission of power shaft drive system, transmission precision is not high, but should avoid non-metallic elastic elements of the elastic coupling and the movement of the elements between the gap between the elastic coupling, in order to avoid High-speed rotation, coupling damage.

Relative displacements caused by manufacturing errors, installation errors, shaft load deformation, foundation deformation, bearing wear, temperature changes (thermal expansion and contraction), relative motion between components, and so on. Generally speaking, the relative displacement of the two shafts is unavoidable, but the direction of displacement generated by the shaft drive in different working conditions, namely, axial, radial, angular and the size of displacement is different, so the basic requirements of centrifugal fan Coupling selection has:

1, high strength, large bearing capacity. Due to the possibility of transient loads on the drive shaft, the instantaneous torque limit of the coupling is required to be more than three times the long-term rated torque.

2, high elasticity, large cushioning, adequate vibration damping capacity. Reduce the amplitude of shock and vibration to the allowable range.

3, there is enough compensation to meet the displacement needs of the two axes during work.

4, reliability and stable performance, and rubber elastic components of the coupling should also have heat-resistant, aging-resistant characteristics.

Second, the selection of centrifugal fan coupling reference factors

1, the relative offset of the two shafts

Coupling connected to the two shafts, due to manufacturing and installation errors, load and temperature deformation, operational wear and tear caused by the gap as well as the design of the two shafts and other factors leading to the relative offset of the two shafts is difficult to avoid. Therefore, the coupling of the relative offset compensation ability is the first factor to be considered when selecting the type.

2, load characteristics

Centrifugal fan start-up load and normal operation of the load is not the same, and with the motor power output changes, will lead to the coupling at different times will be subjected to different loads, so there is a serious impact load and long-term fluctuations in the load, should be selected with a buffer damping function of the coupling, in order to achieve the elimination of peak load and torsional vibration and adjustment of the system intrinsic frequency, to prevent resonance purposes.

3、Operating speed

The size of the working speed of the coupling is directly related to the size of the centrifugal force and deformation of the elastic element of the coupling parts, too large a speed will lead to increased wear and tear, lubrication deterioration, connection loosening. Coupling working speed range is based on the coupling of different material strength of the permissible linear velocity and the upper limit of the outer edge size, calculated to determine the permissible speed range of different materials, varieties and specifications of the coupling is different.

4. External dimensions

The external dimensions of the coupling must comply with the installation and dismantling space allowed by the device. In the case of meeting the requirements of use, should be selected with excellent manufacturing process, easy to install and disassemble, easy to adjust, simple maintenance, no need to move the two connecting shafts to replace the wear parts of the coupling. For large fans, the two connecting shafts are difficult to adjust the precision of alignment, should be used for long service life, easy to replace the wear parts of the elastic coupling. In the underground and other inconvenient maintenance work place, or a long time running and not easy to stop the place, should be used without lubrication or maintenance cycle long and easy to maintain the coupling. Reduce downtime and improve productivity.

5. Working environment

In the selection of centrifugal fan coupling and its protective measures, should consider the temperature, humidity, water, steam, dust, acid and alkali, oil, corrosive media and radiation and other working environment. In the high and low temperature, acid and alkali and corrosive media environment, the elastic element should be selected metal elastic element or nylon, polyurethane elastic coupling, should not choose ordinary rubber elastic coupling. It has higher corrosion resistance, high and low temperature resistance, abrasion resistance and strength than rubber, but its elasticity and cushioning performance are not as good as rubber.