Some gyroscopic systems are so large that they do not have suitable dynamic balancing machines to support operation; some small factories do not have the working conditions for balancing with dynamic balancing machines; some gyroscopic working environments are high heat or high electromagnetic fields, etc. Hysteresis expansion and deformation, etc., have damaged the balance achieved on the dynamic balancing machine; and due to transportation or maintenance, the balanced rotating body needs to be reassembled; all these situations require on-site dynamic balancing. On-site dynamic balancing may include performing one-sided static balancing and dynamic balancing on the flexible rotating body.
The method of static balance is very simple. First, place the sensor in the direction of the additional support of the slewing body (preferably the shortest distance from the calibration surface) and the direction of greater vibration (usually horizontal), and connect a vibrometer to start The magnitude of the vibration response is recorded from the slewing body to the working speed. The high reading is X, which corresponds to the measured unbalance U, and there is a relationship U = kx. For a rigid slewing body, at a fixed speed, whether it is hard The support or soft support, k must be a constant, so there must also be a vector relationship U = kx. In order to find the angle (or phase) of the vector x, the two-turn method can be used for measurement and calculation. That is, at any position of the radius of the slewing body R (mm), place a check mass M (g), then start the slewing body to the same speed, record the vibration response at this time, the high reading is x1, obviously, x1 The original unbalance U and the verification unbalance U1 = MR are generated by the joint action, that is, kx1 = U + Ut. Transform the verification mass M (g) by 180o, and after repositioning, start the rotary body again to the same speed, record this The vibration response at the time, the high reading is X2, there should be kx2 = U-Ut, so using the graphical method, it is easy to solve the vector equation.
For the revolving body that needs to be balanced on both sides, an on-site dynamic balance test instrument capable of measuring the phase should be used. Therefore, a quasi-signal generator needs to be provided on the revolving body, commonly used in the photoelectric type, and synchronization triggered by the vibration signal at the support is also used. The flash lamp, due to the visual pause of the human eye, will learn to observe the slewing body at a standstill. You need to set 0 °, 90 °, 180 ° ... and other angle marks on the calibration surface in advance, so that you can observe the set 0 ° angle mark and a fixed position (for example, horizontal direction) when the internal light is synchronized. The angle between them.
With its quasi-signal, the complex amplitude XL and XR that can determine the vibration response at the support can be used to calculate the amount of unbalance according to the coefficient effect method. When performing on-site dynamic balancing, the stiffness matrix or mass matrix of the system is usually not known, and it is not easy to determine the stiffness or negative characteristics of the support in order to further simplify the dynamic stiffness matrix. At this time, the dynamics of the system can be obtained by experimental methods The flexibility matrix, and then through the inverse matrix to find the stiffness matrix. This method is called the influence coefficient method, and is also widely used in the multi-correction surface balance of flexible rotating bodies.
The influence coefficient method is more convenient to operate with complex numbers. The coefficient matrix elements are also complex numbers, so the influence of Yin Ni can be considered, instead of reducing the Yin Yin supported as much as the soft support dynamic balance machine or hard support dynamic balance machine And when separating the solution, ignore it. The elements of the impact coefficient matrix are numerical values, and all tests should be carried out at a fixed speed. If the speed changes, the value of the impact coefficient matrix will also change.
Deli Soup Cup,Plastic Sealed Sauce Box,Disposable Sauce Containerqq,Food Sealed Storage Container
walson groupe , https://www.hagarbagebag.com