Hi, Morio has come back. Last time, we discussed the angular contact ball bearings used in the rear of the SPC50’s feed shaft, but this time, I’d like to focus on the tapered roller bearings used at the front.

Tapered roller bearings, as their name suggests, have rollers that are shaped like cones. This design offers two significant advantages: high load capacity and robustness against axial loads. The conical shape of the rollers allows for line contact rather than point contact, which enables them to support greater loads. Moreover, the angle of contact between the rollers and the tracks is oriented axially, enhancing the bearing’s ability to withstand axial loads and contributing to higher rigidity and improved feed accuracy. In the SPC50, we use two tapered roller bearings in reverse orientation, similar to the angular contact ball bearings at the rear, to enhance load resistance.

However, these bearings can be challenging to handle due to the high load and large contact area which can lead to friction and heat generation during operation. Therefore, precision in component machining and assembly is crucial. A particularly important process in this regard is “Preloading.” Preloading refers to the intentional load applied within the bearing, which presses the rollers between the inner and outer rings, ensuring proper contact within the bearing. This helps reduce vibration and noise, stabilizes operation, and improves durability.

Another critical component is the “spacer,” which is designed to manage preload by adjusting the thickness of parts within the bearing. It helps prevent wear and damage between rollers and evenly distributes the load, enhancing the bearing’s ability to handle stress.

The management of preload varies depending on how the bearing’s roller angles are targeted. At our company, we take the following measures in assembling bearings:

1. We check for wear and damage on the bearings and related components. If any wear or damage is found, it can affect the performance of the bearing and potentially lead to premature failure.
2. Before installation, we carefully check the dimensions of all parts to ensure that the proper clearances are maintained between the shaft and housing.
3. We use specialized tools, such as press-fitting tools, to evenly loosen and expand the inner and outer rings for proper fitting. Although “shrink fitting” with heating devices is sometimes used, our company avoids this to prevent adverse effects due to thermal expansion.
4. We adopt dimensional tolerances that consider assembly, maintenance, required precision, and rigidity, and adjust the assembly accordingly.
5. After installation, we perform a rotation test on the bearing to measure startup torque and displacement. We also check for any unusual sounds or vibrations and make adjustments as necessary.
6. Proper adjustment of preload requires specialized skills and measurement tools.

Technology continually evolves, but the precise work on small details can significantly impact the overall performance. By deepening our skills and knowledge in these areas, we strive to provide better products. This investigation has been very enlightening, and I look forward to continuing to delve into these technical aspects in future posts. Stay tuned for more!

#This blog is made by generative AI from original text.