Brass retainer

The bearing retainer also called bearing cage.

It keeps the ball or cylinder evenly spaced around the raceway to prevent ball to ball contact and allow higher speeds.

To achieve this, the bearing retainers need to have burr-free surface and low Ra value.

So the friction force is greatly reduced.

In this article, we discuss the example of brass bearing retainer surface improvement with the vibratory finishing process.

This process is cost-effective and time-saving.

1. Parts condition before finishing

Parts condition before finishing

2. Parts surface requirement

  • Remove the burr coming from the machining process
  • Reduce surface roughness
  • Improve parts surface brightness

3. How we process the parts

Step(1) Grinding(2) Polishing
MachineVibratory Tub with dividersVibratory Tub with dividers
Tumbling Speed50/60HZ (full speed)50/60HZ (full speed)
Chip TypePlastic Media TET/Cone Middle cuttingZirconia ball 3-4mm
Media to Parts RatioOne part per compartmentOne part per compartment
Compound TypeLC-13, PH 8 (mild grinding compound)HM-3 with HX-0
Water LevelJust cover the massJust cover the mass
Tumble Time60 min20 min
Notes—Manually take the parts out of the machine, and rinse themManually take the parts out of the machine, and rinse them

4. Parts condition before and after polishing

Parts condition before and after polishing

Parts condition before and after polishing 1

The upper part is the one without the tumbling process.

And the part below is the one after deburring and polishing.

You would clearly see the burr after the cutting process is removed after vibratory tumbling.

If you take a close look, the edge is rounded and the surface is smooth.

5.   Other considerations

Brass is a soft metal material, so we should prevent parts-on-parts impingement.

To increase parts productivity, we can use a trough vibratory tub with separated compartments.

This can avoid parts hitting marks.

Parts condition before and after polishing 2

Parts condition before and after polishing 2

As soon as we finish the first step (plastic tumbling media process), we can put brass parts to the zirconia ball chamber. As a brass retainer manufacturer, you can prepare two machines.

One machine is filled with plastic media and another with zirconia ball.

When you process your parts in the second process, you can deburr the new batch in the first machine.

In addition, you don’t bother to change the media.

Therefore, you can greatly reduce the downtime and increase productivity.

Because the polishing time is less than the deburring process, so the second machine can be a smaller size.

6. Conclusion

In this article, we explained an example of brass retainer parts deburring and polishing.

It is a big part with the delicate surface.

The content includes the parts initial condition, surface requirement, our process to finish, and also comparison before and after tumbling.

This process is simple and repeatable.

Yet, it is cost saving and time-saving.

However, the same parts surfaces from different manufacturers may not the same.

So we suggest our client send us a real sample to check in our lab.

Then we can give our tips on how to get the desired finish with lowest possible cost.