Common solution to the noise of synchronous belt wheel
Noise control mainly from two aspects: one is from the source to find ways that eliminate or weaken the intensity of the sound source, which is the fundamental method of noise control, is also the focus of this discussion; two is to take measures such as sound absorption and insulation from the transmission of noise, transmission or noise shielding to. The noise source analysis of synchronous belt drive, there are two main aspects: one is due to two turns, due to the unbalanced centrifugal force excitation sound, on the other hand is due to belt and belt wheel meshing, caused by gas disturbance resulting in aerodynamic noise. The main factors that produce the noise in two aspects are listed as follows.
1 the main factors causing the imbalance of the rotation
(1) the shape and position tolerance of the wheel itself, including the gear tooth to the tolerance, tooth thickness tolerance and axial and radial pulsation, etc.. The higher the manufacturing precision of the belt and the belt wheel, the smaller the impact of meshing, the higher the accuracy of the synchronous belt transmission, the lower the noise. Because of the synchronous belt and pulley are produced by professional manufacturers, can effectively control the manufacturing precision, and will not go.
Two axle parallelism: in general, with the increase of parallel error, the sound pressure level increases gradually. So, the axis of the shaft and the motor axis is installed to ensure the installation of parallel, two axis parallel to limit (0.003 ~ 0.005) to C (C is the two axle center distance).
(2) the two axle rotary precision because of the two wheels will be high-speed rotary, rotary speed of more than 6000 R / m i n, so as not to act when the high-speed rotary balance, unbalanced centrifugal force will cause the shaft and the motor shaft of the tremor, and thus stimulate strong noise. For most manufacturers, only on the spindle (including pulley) manufacturing assembly for the dynamic balance, the motor shaft must also balance into action, the belt wheel mounted on the shaft of motor, line balancing instrument for testing the rotary shaft and the use of material removal method (dynamic balance on the belt wheel.), to the requirements of G 2.5 accuracy class of dynamic balance of the final. Through this treatment, can reduce the transmission of vibration and noise in varying degrees, to improve the synchronous belt and the life of the main shaft is also very good.
(3) pre tightening force and horizontal synchronous belts and V belts, relying on synchronous belt tooth meshing transmission power, so there is no need to pre tension greatly, excessive tension will seriously affect the service life of the band, serious noise. In the start-up and impact torque under the action of small tension will lead to synchronization with jump teeth, resulting in tooth root fracture. How to choose the appropriate tension method is more accurately by ultrasonic tension tester, if there is no instrument, also can be made with a simple set of tools, according to the following method: determination as shown in Figure 1, close to the two wheels on one side of the center position of the synchronous belt, applying a test force, will produce a bend the deformation of D, if the d=S / 64 (s for single measuring length, with the unit: mm) it may be considered that the belt tension is appropriate. Otherwise, the tension of the 1 belt pulley is adjusted to adjust the tension force of the belt until it is suitable. The value with the type and bandwidth is different, which can be found in the relevant information, such as the 40 m m wide 8 Y U (8 M) d 39 N synchronous belt. The experiment proved that the proper belt tension can significantly reduce the high frequency noise, namely we often say "".