The reducer is an important part of mechanical equipment. Its operating status directly affects the working quality of the unit and the safe operation of mechanical equipment. Once defects or failures occur, it will cause extremely serious consequences. With the continuous development of modern industry, in order to achieve The high-speed and automatic operation of mechanical equipment has put forward more stringent requirements for the transmission error of the reducer, especially the noise control of the reducer. At this stage, the reasons for the noise of the reducer and the treatment plan are studied , has important practical significance.
1 Gear vibration mechanism and reducer fault diagnosis method
The frequency spectrum analysis method is widely used in the diagnosis of reducer. By accurately judging the fault type of the reducer and dealing with potential problems in time, the occurrence of mechanical equipment failure can be effectively avoided. The spectral diagnosis method is mainly based on the gear vibration mechanism, that is, the gear vibration frequency characteristics, natural frequency and mathematical model. The reducer contains a lot of useful information in the vibration. When diagnosing the gear, due to the different installation positions of the sensor, the obtained measurement There will also be some differences in the value of the gear vibration frequency component. As a necessary variable speed transmission component for all kinds of mechanical equipment, the reducer is composed of various parts, mainly including gears, bearings, chassis, fasteners and seals. Combined with practical experience, the failure of the reducer is concentrated in the gear and The design, assembly and maintenance of bearings, especially gears, are the key to ensuring the normal operation of the reducer. Through various analysis and processing schemes, the fault characteristic information of the reducer can be extracted, and the gear fault can be found. This frequency domain Analysis and identification are the most effective methods for reducer spectrum diagnosis.
2 Reasons and solutions for the noise generated by the reducer
Based on the gear vibration mechanism and the fault diagnosis method of the reducer, the noise forming factors of the reducer can be analyzed from four aspects: design, manufacture, installation and maintenance.
(1) Design reasons and solutions
The key link in the design of the reducer is the determination of the gear accuracy grade. Neglecting the design of the gear accuracy grade is one of the main reasons for the noise of the reducer. Therefore, while considering economic factors, the designer should also pay attention to the gear accuracy grade. Determined, this can not only reduce the transmission error of the reducer, but also effectively reduce the noise. In addition to the gear accuracy grade, the following links should also be designed: ①Gear width, the noise curve of large tooth width is lower than that of small tooth width when the torque is constant. Therefore, if the transmission space allows, the gear width should be increased as much as possible. Reduce the unit load under constant torque and increase the gear bearing capacity, which is also a commonly used method to reduce the transmission noise of the reducer; ② Tooth pitch and pressure angle force, reducing the tooth pitch can increase the contact opportunity between the gears, thereby reducing the gear deflection The second is to reduce the pressure angle of the gear, so that the transmission accuracy can be improved, and the transmission noise can also be reduced; 3. The displacement coefficient, the reasonable choice of the gear displacement coefficient will play two roles. To avoid gear undercut, as far as closed gear transmission is concerned, in addition to meeting the concentric condition, it is necessary to ensure the thickness of the tooth tip, and at the same time to avoid the problem of the interference of the transition curve, so as to improve the gear transmission performance and reduce the noise; ④ Tooth shape trimming and tooth top chamfering, the gear eating surface will be deformed under the action of external force, the tooth top can be cut into a convex shape during design to avoid interference with the meshing gear, which can not only prolong the service life of the gear, but also reduce Noise, but also pay attention to the degree of correction, not excessive, so as not to increase the tooth profile error. Then there is the analysis of the sound radiation characteristics of the gear, and the design of the speed of the power source of the reducer and the structure of the box, which will not be listed one by one here.
(2) Manufacturing reasons and solutions
In the gear manufacturing process, tooth profile error, tooth direction error and radial runout error are prone to occur. These are the main errors that cause the transmission noise of the reducer. In addition to avoiding errors, the following issues should also be paid attention to: ① Assembly Concentricity and dynamic balance, the non-concentricity of the assembly directly affects the balance of the shafting operation, and the noise will be aggravated in the semi-loose and semi-tight state, so the concentricity of the assembly must be guaranteed; ② The hardness of the tooth surface is guaranteed In this case, there will also be some new problems, such as the application of carburizing and quenching technology, although it will increase the hardness of the tooth surface, it will also increase the transmission noise. Transmission noise; ③In the verification of system indicators, the parts and components before assembly and selection will have an impact on the accuracy level of the gear. Once it exceeds the controllable range, transmission noise will be generated. Item indicators are checked.
(3) Installation reasons and solutions
When installing the reducer, if the fuselage and the relevant connecting parts resonate, noise will also be generated. For this, vibration reduction and blocking measures should be taken, and basic materials with high toughness can be selected. In addition, the following issues should be paid attention to: ① Adjust the geometric accuracy of parts and components. If the geometric accuracy of parts and components reaches the specified standard, the installation process should be improved, the resonance problem should be properly handled, and the noise should be effectively reduced; ② If the parts are loose, it should be ensured during installation The fixation of various parts and individual loosening will also lead to inaccurate positioning of the system, resulting in vibration and noise. The assembler should do the relevant work; ③ The transmission parts are damaged, which are mostly caused by improper operation, which in turn causes the system to run. Instability, if damage is found during the installation process, the parts should be replaced immediately so that the system can be controlled at a stable noise level.
(4) Maintenance reasons and solutions
The maintenance of the reducer cannot directly reduce the noise level of the system, but it can ensure the transmission accuracy, so it can indirectly reduce the noise of the reducer. Mainly from the following five aspects: ① Internal cleaning, the impurities and dirt inside the reducer will damage the transmission system, resulting in noise, and internal cleaning should be done well; ② Working temperature, the reducer runs at an abnormal working temperature, Excessive temperature rise will lead to deformation of parts and then noise. Make sure that the reducer runs at normal temperature; ③ Correct use of oil, unreasonable use of lubrication or failure to lubricate in time will cause damage to the gears. During operation, the friction of the tooth surface will generate a lot of heat energy. If the lubrication is improper, the gear damage will affect the accuracy, and then noise will occur. The purpose of maintaining an appropriate clearance in the design is to compensate for thermal changes, and then maintenance.
Use lubricating grease correctly to delay the deterioration trend; ④ Regular maintenance and maintenance, as the load of the reducer increases, its noise will also increase, the reducer should be used correctly, and regular maintenance work, such as oil change, replacement parts, etc., to improve its ability to resist deterioration of the noise level.
3 Conclusion
There are many factors that cause the noise of the reducer. Based on the gear vibration mechanism and the fault diagnosis method of the reducer, the causes of the noise are analyzed from four aspects: design, manufacture, installation and maintenance, and corresponding treatment plans are proposed, in order to be able to analyze the specific Practice serves as a guide.
4 More about VAFEM Flexible Bearings for Reducer
As a precious high quality cylindrical flexible bearings manufacturer and supplier in China, VAFEM can guarantee the quality and precision of the products through complete testing technology and advanced equipment.
Flexible Bearings are mainly used in Reducer. Harmonic transmission includes three basic components: wave generator, flexible wheel, rigid wheel and flexible bearing. Flexible bearings are the core components, and the transmission meets the performance requirements of high deceleration ratio through the elastic deformation of bearings.
In the work of flexible bearing, the inner ring is installed on the elliptical cam, the outer ring is installed on the flexible wheel, and the elastic deformation occurs with the rotation of the cam, which not only bears the cyclic stress load, but also bears the alternating stress load.
Please come to buy Flexible Bearings at the best price and quality from VAFEM. Please contact us for any questions!
2022-08-25