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Professionally provides dynamic balance detection, correction and dynamic balance cleaning equipment for all types of high speed rotating workpieces (from 500 to 10,000 rpm)
Zhuo Xuanjin explains the characteristics of crankshaft soft support and hard support dynamic balancing machine
The soft support and hard support dynamic balancing machine are two forms from the working principle of the crank balancer. Whether it is a hard support balancer or a soft support balancer, the crankshaft is placed on the measuring pendulum of the balance machine. During the measurement, the crankshaft-swing system generates a vibration response due to the unbalanced excitation of the crankshaft, thereby obtaining the imbalance of the crankshaft. The hard-bearing balance machine means that the speed must be less than 3 times the resonance speed to work, so the lower speed (especially the heavy-duty transmission shaft) is generally used. The speed is also related to the sensitivity of the sensor used. If a sensitive sensor is used, a lower speed can be used. Correspondingly, the soft-bearing balance machine means that the rotation speed must be more than three times the resonance speed to detect (the higher the speed, the higher the weight reduction rate), so generally higher speeds are used.
Soft support and hard support dynamic balancing machine features:
(1) Measurement method
The hard bearing balancing machine is a force measuring type, and the working principle is that the centrifugal force generated according to the unbalance amount is proportional to the unbalance amount. Due to the high rigidity of the support, the vibration is small and the unbalanced force acts directly on the support. The soft-bearing balancer is a sizing type, and the working principle is based on the amplitude proportional to the amount of unbalance. Due to the small stiffness of the support and the large vibration, the vibration amplitude of the pendulum system is measured.
In order to convert the vibration signal measured on the pendulum into the unbalanced value of the specified correction plane and radius, the dynamic balancing machine needs to be calibrated, that is, the dynamic balancer measurement system is adjusted. For a given rotor, the balance machine reads Unbalanced amount. The amplitude of the universal hard-supporting dynamic balancing machine is only related to the unbalance amount, the swing stiffness and the balance speed, and is independent of the quality parameter of the crankshaft, so it can be calibrated once when the balancing machine is shipped.
Due to the force measurement principle, the plane separation depends only on the mutual distance between the correction plane and the support plane. Therefore, the hard-bearing balancer only needs to be calibrated once, and the balance of any crankshaft in its specified speed range without the need for on-site calibration is called permanent calibration.
For soft-bearing balancers, the vibration of the pendulum is not only related to the amount of unbalance, but also to the quality of the crankshaft and the parasitic quality (other qualities of the vibration such as the pendulum, coupling, etc.). Considering the plane separation when the double-sided balance is concerned, it is also related to the moment of inertia of the crankshaft about its own axis and about the vertical axis. Therefore, the use of a soft-bearing balancer to balance different crankshafts must be calibrated on site, ie, the balancer is calibrated using a known unbalance (calibrated mass).
(3) Balance accuracy
The soft bearing balancer has a large amplitude and high mechanical sensitivity. The hard-support balancing machine has a small amplitude and requires a more advanced electronic amplifying circuit to achieve high sensitivity. Generally, the balance accuracy is not significantly different due to the soft and hard support, but mainly depends on the technical level and manufacturing quality of the balancer.
(4) Constant balance accuracy
The universal hard-bearing balancer can be transferred to a higher speed when balancing a small crankshaft, and can be turned to a lower speed when the large crankshaft is balanced. The balance accuracy obtained is constant regardless of the crankshaft size. The general-purpose soft-bearing balance machine has less influence on the large crankshaft due to the parasitic quality, and has a large influence on the small crankshaft, and it is difficult to obtain a constant balance accuracy.
(5) Practicality of the crankshaft
The soft support is suitable for light and small crankshafts, the hard support is suitable for medium and large crankshafts; the soft support is suitable for automatic balancing machines and automatic positioning and balancing machines on the production line of small-size and high-volume crankshafts. The hard support is versatile and suitable for many varieties. Production and maintenance of low to medium volume or single piece.
(6) Applicability of initial unbalance
The rigid bearing balancer has high rigidity and high strength, which allows the crankshaft to have a large initial imbalance. On the contrary, the soft bearing balancer has a small rigidity, a thin structure, and a large vibration at an over resonance speed, which is difficult to bear large. The initial imbalance amount.
Because the hard-supporting balance machine has permanent calibration characteristics, it does not need to be calibrated, and the operation is relatively simple. The soft-bearing balance machine must be calibrated every time to balance different crankshafts. The operation is cumbersome and requires the operator to have certain experience. This is one of the reasons why the universal balancer hard support replaces the soft support.
(8) Reliability of use
The rigid bearing balancer has strong structure, impact resistance, no wearing parts and high reliability. The soft bearing balance machine has poor impact resistance and requires careful operation and maintenance.
Guangzhou Zhuo Xuanjin engineer reminds: Dynamic balance machine is a high-precision measuring instrument after all, maintenance personnel require certain electrician knowledge, especially weak electricity knowledge, so choose the approved professional maintenance as much as possible, Guangzhou Zhuo Xuan Jin dynamic balancing machine after-sales maintenance Service consultation: 020-36969823.