1. The reason for the noise of the 90-degree angle reducer

From the current research on the noise of the 90-degree angle reducer, the causes of the noise of the 90-degree angle reducer mainly include the following aspects:

(1) 90-degree angle reducer noise caused by gear processing and design process

The structure of the gear has a great influence on the noise of the 90-degree angle reducer. Generally speaking, the bending strength, contact accuracy, motion accuracy, contact accuracy, manufacturing accuracy, and working stability accuracy of the gears will all have an impact on the noise of the 90-degree angle reducer. The manufacturing accuracy of the 90-degree angle reducer directly determines the noise value of the 90-degree angle reducer, the eccentric force of the wheel body, and the working stability accuracy, which are the keys to controlling gear noise. Therefore, the error will cause intense pile foundation and vibration during the meshing process of the gear, which will cause the gear to produce high-frequency impact sound, which will have a great impact on the normal use of the parts. In addition, gears with poor contact accuracy will also produce a lot of noise. There are two main reasons for poor gear contact. On the one hand, the tooth orientation error affects the contact in the direction of the tooth height; on the other hand, the base pitch deviation and the tooth profile error affect the contact in the direction of the tooth height; the general motion accuracy will cause low-frequency noise, and when the period error increases, the noise will also increase. The eccentricity of the wheel body will cause the vibration of the wheel train, which in turn will make the 90-degree angle reducer produce noise. In addition, in the design stage of the gear 90-degree angle reducer, the accuracy of the precision grade design is directly related to the noise of the gear 90-degree angle reducer, so designers must fully consider economic factors and industrial production needs when determining the gear accuracy grade , so as to make an accurate judgment on the gear precision grade scientifically and reasonably.

(2) Noise generated in the gear manufacturing process

In the gear manufacturing process, tooth orientation error, tooth profile error and radial runout error often occur, and these errors may generate noise. In addition, in the gear manufacturing process, the machining accuracy of the box hole will also affect the operation of the 90-degree angle reducer.

(3) Noise caused by assembly accuracy during installation of 90-degree angle reducer

At present, judging from the reasons for the noise of the 90-degree angle reducer, the two main reasons for the noise of the 90-degree angle reducer are assembly accuracy and manufacturing accuracy. In addition, if resonance occurs between the 90-degree angle reducer body and related parts during installation, the 90-degree angle reducer noise will also be generated. Therefore, the operator must strictly control the quality of building materials when installing the 90-degree angle reducer, and the maintenance personnel must also do the post-maintenance work of the 90-degree angle reducer. Although the maintenance of the reducer cannot directly reduce the noise of the system, it can transmit the precision.

2. The method of fault diagnosis of 90-degree angle reducer

Generally speaking, before diagnosing the reducer, the maintenance personnel must first judge the fault type of the reducer, so as to discover the hidden safety hazards in the reducer in time, and take targeted preventive measures to reduce the harm caused by the failure of the reducer. At present, the common 90-degree angle reducer fault diagnosis method in my country's machining industry is the frequency spectrum diagnosis method. This diagnosis method is mainly based on the vibration frequency characteristics of the gear, the natural frequency of the gear and the corresponding mathematical model for accurate diagnosis. The main reason for applying this diagnostic method is that the vibration of the 90-degree angle reducer contains a lot of information, and the diagnostic personnel can make good use of this characteristic of the 90-degree angle reducer to diagnose faults [3]. In addition, from the past diagnosis experience, the position of the sensor will have a certain influence on the measurement result, and the vibration frequency of the gear is an important basis for the fault diagnosis of the 90-degree angle reducer. Therefore, in order to measure the vibration frequency of the gear more accurately, the workers usually use the accelerometer to measure.

three. Reducer noise control scheme

(1) Noise control scheme in the design stage of the 90-degree angle reducer

In order to deal with the noise problem of the 90-degree angle reducer more effectively, designers must consider various factors when designing the structure of the 90-degree angle reducer to help effectively reduce the transmission error during the operation of the 90-degree angle reducer. achieve the purpose of effectively reducing noise. Specifically, the designer should design the 90-degree corner reducer from the following aspects.

1. Design of tooth pitch and presser foot pressure

The designer should reduce the tooth pitch as much as possible when designing the tooth pitch and presser foot force, which can greatly increase the contact opportunity between the gears, thereby helping to effectively reduce the transmission noise [4]. For example, the noise of the 90-degree angle reducer on the belt is caused by loose anchor bolts or a pair of loose wheels. If the presser foot force and tooth pitch are well controlled, noise can be effectively reduced.

2. Gear width

Generally, when the torque is constant, the noise curve of the large tooth width is lower than the noise curve of the small tooth width. Therefore, in order to reduce the unit load under constant torque and increase the overall bearing capacity of the gear, the designer can effectively reduce the noise generated by the 90-degree angle reducer by increasing the tooth width.

3. Displacement coefficient

When designing a 90-degree angle reducer, the designer must pay attention to the reasonable selection of the gear displacement coefficient, which can effectively reduce the occurrence of gear undercuts, and at the same time can achieve the purpose of easing curve interference. In this way, it can help improve the transmission performance of the gear, thereby effectively reducing the noise of the 90-degree angle reducer.

(2) Noise control plan in the manufacturing process of 90-degree angle reducer

In the manufacturing stage of the 90-degree angle reducer, the most important point is to do a good job in error handling. First of all, the hardness of the tooth surface must be ensured, although in some cases, even if the hardness of the tooth surface is guaranteed, some new problems will start to appear. In addition, it is necessary to control the concentricity assembly to ensure that the entire 90-degree angle reducer can be in a state of dynamic balance, because the concentricity of the assembly will directly affect the balance of the gear shaft operation. If it is in a semi-loose and semi-tight state, it will aggravate the noise problem. The third point is to systematically verify the indicators before assembly, and control the indicators of all parts within a certain range to avoid the problem of gear accuracy grade caused by poor quality of parts, thereby effectively reducing the probability of transmission noise.

(3) Noise control plan during the installation process of the reducer

When installing the 90-degree angle reducer, the construction personnel can choose some materials with higher toughness as the basic material for the installation of the 90-degree angle reducer. At the same time, the accuracy of the parts should be reasonably controlled. Optimize the installation process of the 90-degree angle reducer, which can solve the resonance problem and reduce the noise. In addition, the installer must do a good job of reinforcement when installing each component, so as to prevent the loose components from affecting the operation of the 90-degree angle reducer system.

(4) Post-repair and maintenance of 90-degree angle reducer

In order to better ensure the service life of the 90-degree corner reducer, later maintenance work is naturally essential, but in the actual maintenance process, pay attention to cleaning the inside of the 90-degree corner reducer to avoid deceleration due to the 90-degree corner. The existence of debris inside the device will cause damage to the entire transmission system. At the same time, during the operation of the 90-degree angle reducer, the operator should also pay attention to the temperature control in the working environment of the 90-degree angle reducer, and try to avoid running the 90-degree angle reducer in a high temperature environment, because the internal parts of the 90-degree angle reducer The characteristics of the 90-degree corner reducer are usually not very stable, and it is easy to deform if stimulated by high temperature conditions, which makes the 90-degree corner reducer produce noise. In addition, maintenance personnel should adjust the position of the motor shaft and the high-speed shaft of the reducer in time in the later maintenance process, and replace the parts of the reducer in time, which will help to effectively improve the anti-noise level of the reducer.