For flexible rotors, high-speed dynamic balancing is generally required to ensure a good balance state. This article specifically explains high-speed dynamic balancing machines. The dynamic characteristics of the high-speed dynamic balancing machine swing frame directly affect the accuracy of the dynamic balancing test. In order to improve the dynamic characteristics of the dynamic balancing machine swing frame, the influence of the dynamic main stiffness rod on the dynamic stiffness of the balancing machine swing frame was analyzed.
Firstly, a high-speed dynamic balancing machine swing frame model is established using finite element analysis software ANSYS, and modal analysis is performed to obtain the various frequencies and modes of the dynamic balancing machine swing frame, excluding the fixed modes that have no effect on the operation of the dynamic balancing machine swing frame. Perform modal analysis on swing frames with different structures, compare and calculate the structures, and remove structures that do not affect the natural frequency of the dynamic balancing machine swing frame. Secondly, based on simplifying the model, five improvement methods for the main stiffness rod of the swing frame are proposed. Harmonic response analysis was conducted on various improved swing frames to obtain the relationship curve between dynamic stiffness and frequency. The results showed that changing the structural dimensions or material properties of the main stiffness rod appropriately would change the dynamic stiffness of the swing frame. Therefore, in the design process, the structural dimensions and material properties of the main stiffness rod can be appropriately changed to meet the design requirements of the dynamic balancing machine swing frame.
Below are several targeted issues for high-speed dynamic balancing machines:
The dismantling and installation of gas turbines and their control systems during testing are relatively expensive. If there is no special need or sufficient cost support, it is not advisable to choose such solutions. Only considering the unbalanced effects that may be caused by processing and disassembly, while ignoring the effects of low-temperature phenomena and high-speed airflow components on vibration under actual working conditions.
1. High speed drive problem: Initially, a high-speed dynamic balancing machine test was designed for the rotor to study the rotor power under high-speed rotation and the technology that affects the high-speed dynamic balancing machine. Due to the significant gap in precision and high-precision machining scale between China and developed Western countries, as well as the technical confidentiality of high-precision machine tool equipment and instruments in foreign countries, it is difficult for China's technical level in the machining and disassembly process of micro turbine engines to meet the needs of ultra-high precision. Due to the insufficient quality of rotor materials and errors in the machining and disassembly of blades and impellers, instability and significant unbalanced mass of the rotor may occur.
2. Rotor detection issue: In order to simplify the testing process, the design of the induction rotor is an idealized technology with excellent dynamic balancing characteristics. The rotor operates ideally in complex and difficult working conditions. In summary, it is necessary to perform process dynamic balancing on the centimeter level rotor to ensure that it not only exhibits excellent vibration characteristics at operating speed, but also works stably during acceleration or deceleration. Choosing an electrical drive for testing not only reduces the cost of testing, but also makes it easier to master and protect the motor drive, which is the best solution. However, it is rare to find motors with sufficient power to achieve 120000 revolutions per minute, and there are no truly good cases or experiences yet. The driving of high-speed dynamic balancing machines relies heavily on thermal power.
3. Balancing machine bearing problem: The working speed of this type of micro high-speed rotor itself is far above its second speed, which belongs to flexible rotors. If the dynamic unbalance is too large, it is even difficult for the rotor to reach this speed during the acceleration process, making it unable to work normally. Whether the balancing machine bearings on the market can truly meet this need still needs further testing and demonstration.
Soft supported high-speed dynamic balancing machine
The soft supported high-speed spindle dynamic balancing machine adopts universal joint transmission, which can obtain multiple balancing speeds with high accuracy, easy operation, and high work efficiency. High speed dynamic balancing machine is suitable for vacuum pumps, centrifugal pump rotors, motor rotors, grinding blade shafts, rollers, turbine rotors, etc.
A high-speed dynamic balancing machine is an instrument used to measure the unbalance of a rotor and calibrate it based on the measured results. High speed dynamic balancing machines are widely used in various fields and can be involved in various industries; It can perform dynamic balance measurement on single-sided, double-sided, and multiple calibration surfaces. The equipment has the characteristics of high efficiency, accurate precision, intuitive display, reliable quality, and easy maintenance.
Firstly, we need to mention that the main structure of its engine is a micro high-speed rotor dynamic balancing system, and its characteristics will directly affect the overall performance. Under current technological conditions, vibration signal detection can be achieved. A high-speed dynamic balancing machine can achieve a centimeter level rotor dynamic balancing machine, but there is still no high-speed dynamic balancing machine with a balancing speed of up to 120000 revolutions per minute in China, and there is no mature micro and high-speed dynamic balancing technology.
Although the basic conditions required for a rotor dynamic balance test bench with a balanced working speed of 120000 revolutions per minute, such as high-speed drive, frequency converter, supporting bearings, sliding equipment, vibration sensors, and signal processors, are difficult to meet in such simplified designs.
The dynamic imbalance caused by unbalance at working speeds of over 100000 revolutions per minute can seriously affect the vibration and stability of the engine. The deflection and internal stress of the rotor caused by dynamic imbalance can accelerate the aging of components such as bearings and shaft seals, reduce work efficiency, and even cause various types of work to malfunction. Considering the ability to work for a long time, lifespan, cost, and the presence of the original unbalanced rotor's dynamic reaction force impact mechanical bearing support, it is the best solution.
Firstly, a high-speed dynamic balancing machine swing frame model is established using finite element analysis software ANSYS, and modal analysis is performed to obtain the various frequencies and modes of the dynamic balancing machine swing frame, excluding the fixed modes that have no effect on the operation of the dynamic balancing machine swing frame. Perform modal analysis on swing frames with different structures, compare and calculate the structures, and remove structures that do not affect the natural frequency of the dynamic balancing machine swing frame. Secondly, based on simplifying the model, five improvement methods for the main stiffness rod of the swing frame are proposed. Harmonic response analysis was conducted on various improved swing frames to obtain the relationship curve between dynamic stiffness and frequency. The results showed that changing the structural dimensions or material properties of the main stiffness rod appropriately would change the dynamic stiffness of the swing frame. Therefore, in the design process, the structural dimensions and material properties of the main stiffness rod can be appropriately changed to meet the design requirements of the dynamic balancing machine swing frame.
Below are several targeted issues for high-speed dynamic balancing machines:
The dismantling and installation of gas turbines and their control systems during testing are relatively expensive. If there is no special need or sufficient cost support, it is not advisable to choose such solutions. Only considering the unbalanced effects that may be caused by processing and disassembly, while ignoring the effects of low-temperature phenomena and high-speed airflow components on vibration under actual working conditions.
1. High speed drive problem: Initially, a high-speed dynamic balancing machine test was designed for the rotor to study the rotor power under high-speed rotation and the technology that affects the high-speed dynamic balancing machine. Due to the significant gap in precision and high-precision machining scale between China and developed Western countries, as well as the technical confidentiality of high-precision machine tool equipment and instruments in foreign countries, it is difficult for China's technical level in the machining and disassembly process of micro turbine engines to meet the needs of ultra-high precision. Due to the insufficient quality of rotor materials and errors in the machining and disassembly of blades and impellers, instability and significant unbalanced mass of the rotor may occur.
2. Rotor detection issue: In order to simplify the testing process, the design of the induction rotor is an idealized technology with excellent dynamic balancing characteristics. The rotor operates ideally in complex and difficult working conditions. In summary, it is necessary to perform process dynamic balancing on the centimeter level rotor to ensure that it not only exhibits excellent vibration characteristics at operating speed, but also works stably during acceleration or deceleration. Choosing an electrical drive for testing not only reduces the cost of testing, but also makes it easier to master and protect the motor drive, which is the best solution. However, it is rare to find motors with sufficient power to achieve 120000 revolutions per minute, and there are no truly good cases or experiences yet. The driving of high-speed dynamic balancing machines relies heavily on thermal power.
3. Balancing machine bearing problem: The working speed of this type of micro high-speed rotor itself is far above its second speed, which belongs to flexible rotors. If the dynamic unbalance is too large, it is even difficult for the rotor to reach this speed during the acceleration process, making it unable to work normally. Whether the balancing machine bearings on the market can truly meet this need still needs further testing and demonstration.
Soft supported high-speed dynamic balancing machine
The soft supported high-speed spindle dynamic balancing machine adopts universal joint transmission, which can obtain multiple balancing speeds with high accuracy, easy operation, and high work efficiency. High speed dynamic balancing machine is suitable for vacuum pumps, centrifugal pump rotors, motor rotors, grinding blade shafts, rollers, turbine rotors, etc.
A high-speed dynamic balancing machine is an instrument used to measure the unbalance of a rotor and calibrate it based on the measured results. High speed dynamic balancing machines are widely used in various fields and can be involved in various industries; It can perform dynamic balance measurement on single-sided, double-sided, and multiple calibration surfaces. The equipment has the characteristics of high efficiency, accurate precision, intuitive display, reliable quality, and easy maintenance.
Firstly, we need to mention that the main structure of its engine is a micro high-speed rotor dynamic balancing system, and its characteristics will directly affect the overall performance. Under current technological conditions, vibration signal detection can be achieved. A high-speed dynamic balancing machine can achieve a centimeter level rotor dynamic balancing machine, but there is still no high-speed dynamic balancing machine with a balancing speed of up to 120000 revolutions per minute in China, and there is no mature micro and high-speed dynamic balancing technology.
Although the basic conditions required for a rotor dynamic balance test bench with a balanced working speed of 120000 revolutions per minute, such as high-speed drive, frequency converter, supporting bearings, sliding equipment, vibration sensors, and signal processors, are difficult to meet in such simplified designs.
The dynamic imbalance caused by unbalance at working speeds of over 100000 revolutions per minute can seriously affect the vibration and stability of the engine. The deflection and internal stress of the rotor caused by dynamic imbalance can accelerate the aging of components such as bearings and shaft seals, reduce work efficiency, and even cause various types of work to malfunction. Considering the ability to work for a long time, lifespan, cost, and the presence of the original unbalanced rotor's dynamic reaction force impact mechanical bearing support, it is the best solution.
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