The surface quality of mechanical parts plays a very important role in the overall quality of parts, and the surface waviness is also one of the important factors affecting the surface quality of parts. The influence of surface waviness on the performance of mechanical parts is similar to that of surface roughness, but also has its own characteristics, especially for some products. Then, what are the effects of surface waviness on the surface roughness of parts?
First, we need to know how the ripples are produced. Let's take a look at the analysis of the accelerated screening:
1. Causes of surface ripples
According to the rapid screening analysis, there are two main reasons for waviness in cutting: one is the simple reproduction of tool vibration marks on the workpiece surface; The other is that cutting vibration and waviness are causal.
2. Influence of surface waviness on surface roughness of parts
(1) Rolling bearing
The vibration of bearing during operation is the main factor causing surface waviness. The shape error mainly reflects the low-frequency component of the part surface, and the influence of these low-frequency components on the bearing vibration is much smaller than the high-frequency component. The waviness of the ball will also cause the vibration value of the steel ball to rise, resulting in greater overall vibration and noise of the rolling bearing. The greater the vibration and noise of rolling bearings, the higher the surface waviness of mechanical parts.
The waviness has a great impact on the performance of rolling bearings. Therefore, controlling the surface waviness of bearing raceways and rolling elements within a certain range plays a very important role in improving the machining accuracy of rolling bearings and extending the service life of bearings.
(2) Mechanical contact seals
With the increase of surface waviness, the fluid film will bear more load, and at the same time, the leakage will increase. From the view of seal design and use requirements, for a working condition, the ripple amplitude should be kept at the optimal value.
(3) Optical medium surface
The influence of surface waviness on light scattering from optical media surface cannot be ignored. When the surface roughness of the optical medium is very high and has reached the nanometer level, if the reflectivity does not improve significantly, the main reason is due to the influence of waviness.
3. How to improve the cutting waviness
(1) Reduce or eliminate the vibration of the process system: the vibration of the process system is the main cause of waviness, so try to reduce or eliminate the vibration.
(2) Change the cutting amount: In grinding, the waviness can be reduced by increasing the wheel speed without affecting the vibration of the process system.
(3) Correctly select the grinding wheel and improve the hardness of the workpiece: the type of grinding wheel abrasive has an impact on the grinding waviness. If the waviness does not meet the requirements, the grinding wheel of different brands can be replaced.
(4) Trim the grinding wheel and use the cooling lubricant.
