After years of testing, we have summarized some performance indicators for evaluating the quality of the reducer, especially the areas that are prone to problems in the development of the reducer. Whether it can be solved and when it can be solved depends on the R&D strength.
1. Oil spill
Regardless of the reducer, this is a problem that must be faced. The cause of oil leakage is more complicated, involving oil seal brand, oil packaging, shaft processing technology, use method, etc., and oil leakage is divided into real oil leakage and fake oil leakage.
The so-called false oil leakage refers to oil leakage shortly after the operation, the amount of oil leakage is small, and no longer occurs after a short time. This is generally the release of internal pressure. Once the pressure is released, it will be fine. The time point when the actual oil leak occurs is uncertain. It may be leaked at the beginning. At this time, it may be a product quality or assembly quality problem; it may also occur after a long time of operation. This is generally an oil seal life problem (use Except improper).
Many people are willing to use oil spills to attack domestic reducers. Yes, it is true that on this issue, the probability of occurrence of domestic reducers is relatively high. It may be that the technology is immature, or the use of relatively general oil seals.
However, it must be said that this is by no means a characteristic of a domestic reducer, it is an imported reducer. Let’s not talk about the brand. It is not a single one. I have also tested the oil leakage. Those customers who have used imported brand robots will also be aware of this problem.
2. Accuracy
There are two types, one is the angular transmission accuracy, which will be marked in the reducer manual, which affects the absolute positioning accuracy of the robot; the other is the repeat positioning accuracy, which is not in the reducer manual. What affects is the repeated positioning accuracy of the robot. Angle transmission accuracy is generally provided by reducer manufacturers with professional equipment, but customers can also design some simple methods to measure them. The same is true for repeat positioning accuracy.
For the new reducer, it is OK for many manufacturers to reach the nominal 1 arc minute or less, but the biggest problem is consistency and stability. It is possible that most manufacturers have reached the standard accuracy at the beginning, but after a few months, either the accuracy will jump up and down, or it will get worse and worse.
The same is true for repeat positioning accuracy. It is no problem to achieve high repeat positioning accuracy in a short time, but it is difficult to maintain it after a long time.
3. Fever
This is more intuitive, but a point that fewer people pay attention to. In fact, heating is also related to the accuracy mentioned above. The accuracy of the reducer depends on the degree of meshing of the gears. If the meshing gap is too large, the accuracy of the reducer will be poor. However, the accuracy of the reducer will be improved by the method of micro-interference, but it will cause excessive heat generation. On the RV, the difference in heat generation using the Teijin structure is not so obvious, and the same is the harmonic reducer, the degree of heat generation of different brands is much different.
Of course, heat is not only related to gears but also related to grease and assembly. The quality of grease and assembly capabilities will have a significant impact. There is a lot of detailed craftsmanship here, depending on the technical capabilities of each robot manufacturer.
4. Life
Life is also the point where domestic reducers have complained the most. Everyone always complains about the short life of the reducer, but there are not many people who can clarify what is short.
In fact, the life of the reducer mainly depends on the life of the bearing. Generally speaking, the bearing is the first to break, especially the harmonics. In the case of RV, the planetary structure is also the point of easy damage.
Many people complain that the bearings used in domestic reducers are not good. There are two points for this: one is that the bearing is really bad, and it may be that defects in materials or workmanship cause the bearing to fail to reach that life.
Another situation is that even if you use the same bearings as HD, you cannot guarantee 100% of the life. The reason is that in the harmonic industry, there is a certain probability of premature wear of bearings, which I have been confirmed by major manufacturers.
That is to say, this is an industry bottleneck, that is, there is a small probability that the bearing will be broken inexplicably, and it cannot be found in the early stage. At this time, whether there is a problem with the reducer itself or a customer problem, there is actually a gray area and a place for wrangling. There are also differences in this probability between different brands.
You have to ask the manufacturer what the probability is. It is estimated that they will not be able to answer it, or they dare not answer you directly. Generally, the official answer will say within 10%. This is a statistical probability. How did this statistical value come from? Then who has such a large sample to make statistics?
5. Transmission efficiency
In fact, this has something to do with the accuracy, heat generation, grease, etc. mentioned earlier. Transmission efficiency is also one of the important evaluation indexes of reducer. To test the transmission efficiency also requires professional equipment, and it is difficult for customers to measure specific data by themselves. However, it is possible to make a horizontal comparison.
Heat is the most intuitive way to compare. Energy is conserved. If the heat is larger, it means that more power of the motor is used to eliminate friction, and the output power will naturally be less. With less output power, the load capacity is naturally weak, the acceleration is naturally small, and the beat is naturally slow.
