A big gear mesh problem occurred for the first order of slewing bearings we delivered to our new customer.
Resulting in metal slivers being carved off of the gear, as in the attached photos.
The customer assumed this to be some sort of profile incompatibility between the pinion and slewing bearing gear.
If we were the customer, this problem had never occurred with the previous supplier, but occurred when working with us, we would also think it’s probably our problem.
We totally understand his thoughts, and this seems very frustrating.
So the first thing to do is to let the customer know that we take this problem seriously and that, if it’s indeed our product problem after investigation, we will take responsibility.
Though we think that this might be an installation problem, and we asked the customer to provide the mounting center distance.
The customer provided the center-to-center distance as 27.24", and our calculation is 27.25", which is the 0.01" difference causing the gear meshing problem.
So, we suggested the customer move the pinion a little bit further, to get a larger mounting center distance and backlash.
But the customer said that they adjusted the backlash as usual and that the interference between the tip of the pinion and the root of the slewing bearing gear is something they have not seen before. And they did some minor grinding near the tip of the pinion teeth, to provide a smoother mesh.
It seems like the customer is still unsure about the slewing bearing’s quality.
So we did the following three things:
👉 1. We not only checked our gear cutting inspection report and final production inspection report again, but we also inspected our production in the facility and told the customer it shows all the gear data is good.
👉 2. We even made a 3D simulation in Solidworks for the slewing bearing and gearbox pinion meshing simulation at a center distance of 27.25" to verify that there is no pinion tip and slewing bearing gear root interference.
👉 3. What’s more, we told the customer that we understand reputation is hard to build but easy to destroy, we cherish our brand reputation more than anything else. If we do have a quality issue, we will never find any excuses.
After the customer checked the simulation video and did his analysis, he finally admitted that they may be setting this mesh too tight.
And asked us if we have recommendations for a minimum backlash, and how it should be measured?
This gives me some comfort that the customer starts to try our suggestions and asks us for help.
We suggest 0.016"-0.028" (0.4-0.7 mm) for the slewing bearing gear and pinion, and to show the backlash measurement as the attached picture.
Finally, the customer was comfortable with this, and no additional action. We feel relieved.
🙏 Salespeople not only need expertise but, more importantly, EMPATHY!