How do transmission gears control noise?

If you want to reduce the noise of gear transmission, the premise is that the type and mechanism of noise generation need to be analyzed in detail.

1. Category
Gear transmission noise can usually be divided into two categories, one is self-sound noise, and the other is acceleration noise.
Self-sounding noise refers to the sound radiation formed by the vibration of all components due to the influence of the meshing force when the gear teeth are engaged.
Acceleration noise refers to the sound radiation formed during the meshing process of the gear teeth, because after it is subjected to a great impact, it will not only cause acceleration, but also disturb other different media.

2. Mechanism
From the perspective of open-toothed gear transmission, the self-sounding noise is generated from the different places such as the transmission shaft and the wheel body, and the acceleration noise is generated from the impact of the gear teeth. From the perspective of closed gear transmission, after the gear body vibrates and the drive shaft is used, the bearing will vibrate. On this basis, the vibration of the gearbox wall will produce self-sound noise. The acceleration noise is under the premise that the air in the gear box is radiated, and then the gear box is used for radiation. It can be seen from this that the size of the gear transmission noise is not only directly and closely related to the dynamic excitation of the gear teeth meshing, but also has a relationship with the box structure and the wheel structure.

The reasons for the noise generated by the gear transmission are embodied in the following points:
First, the contact accuracy between the gearbox and the gear train is relatively low, and the bearing clearance is not very reasonable.
Second, when processing gears, the roughness of the gears is very large and there is a relatively large error between the shape of the gears. Third, when designing gears, the structure of the gear box does not have scientific rationality and The shape of the tooth profile is not repaired or the repair is not very strict, etc.

3. Specific control measures of gear transmission noise After a detailed analysis of the gear transmission noise, the following is an effective control of the gear transmission noise from the aspects of the material and type of the gears and the set parameters. Material: When selecting gear materials, some high damping materials should be selected under the premise that its strength is allowed, which plays a certain role in noise control. Because non-metallic materials can usually greatly reduce vibration and reduce noise fundamentally, on the basis of satisfying its use requirements, some metal materials should be selected for the large gear, and some non-metallic materials should be selected for the pinion gear. , only in this way can the noise be controlled. Type: The meshing of gear teeth is often related to the type of gear. The spur gear teeth in the gear belong to the contact line of the gear width when they are in contact, although the helical gear also belongs to line contact, which is different from the spur gear. It is the helical gear that meshes through one end of the tooth top. In the initial stage, the contact line slowly becomes longer, then gradually shortens, and finally ends when it is disengaged from the meshing. Because compared with the spur gear transmission, the helical gear transmission has many advantages, for example, the helical gear transmission mesh line is relatively large and the bearing capacity is relatively high, etc., so the noise generated by the helical gear transmission is naturally also will be lower than the noise produced by a spur gear drive. Therefore, when choosing gears, you should choose helical gears as much as possible.
Collection parameters:

modulus. If the load of the gear is relatively large, it is necessary to select and use a relatively large module. At this time, the bending deformation of the tooth root becomes a very important factor, and the larger the module of the gear is, the more important it is to control the The effect of noise is greater. If the transmission power of the gear is relatively small, it is necessary to select and use a relatively small module. At this time, the gear machining error is a very important factor. Selecting a relatively small module can greatly increase the number of teeth of the gear. , It is of great significance to improve the balance of gear transmission, thereby reducing the noise of gear transmission.
Diameter and number of teeth. If the module of the gear has been determined, no matter whether the diameter is changed or the number of teeth is changed, the amount of bending or the elastic stiffness will change to varying degrees. From a certain point of view, although there is no great relationship between machining accuracy and diameter, if the diameter gradually increases, the radiation area of ​​noise will naturally continue to increase.
Therefore, the diameter of the gear must be reduced as much as possible.

Control cabinet noise
In a series of processes of making the box, rubber should be applied to the inside of the box or those high-damping materials should be selected and used as much as possible, so as to control the noise. In addition, the inner wall of the box can also be thickened to a certain extent, which can not only significantly improve the rigidity, but also greatly reduce the vibration, and finally control the noise.

Yuhuan FaShiEr Gear Co., LTD. is located in Yuhuan-China automobile parts production base, As a professional China Precision Forged Gears Suppliers and Precision Forged Gears company, our factory with all kinds of mechanical processing equipment, more than one hundred sets, such as 300 T to 1000 T double-tray friction press machine, CNC machine tools, inside and outside round grinder, broaching machine and heating treatment furnace equipment. The company has passed ISO9001:2000 and TS16949:2009 quality management system. The factory has strong technical strength, advanced equipment, completed testing method, strict quality management, all kinds of reliable Precision Forged Gears performance, high quality and reasonable price, long service life and circumspect after-sales service. welcome the customers to come and discuss in the future.