Telecurso 2000 Manutenção 20 Mancais de rolamento II

Summary

This educational video script focuses on bearing maintenance, part of a professional training course with 35 lessons. Lesson 20 discusses the identification and causes of bearing failures, emphasizing the importance of preventive maintenance. It covers primary failure types such as wear, misalignment, corrosion, and electrical damage, and secondary failures like flaking and pitting. The script provides tips on identifying and correcting these issues, highlighting the crucial role of proper lubrication and handling in preventing bearing damage. It prepares viewers for the next lesson on sliding bearings, encouraging them to review their study materials.

Takeaways

• 📚 The video is part of a professional training course with a total of 35 lessons, and this is lesson number 20.
• 🔍 The lesson focuses on identifying and understanding the causes of bearing failures and how to inspect and maintain bearings as a form of preventive maintenance.
• 🛠️ Learning to recognize and correct bearing problems is crucial for effective maintenance and can prevent further damage.
• 🔧 Causes of bearing failure include inadequate lubrication, rough handling, poor alignment, and incorrect assembly.
• 🛡️ Preventive maintenance is key to identifying and addressing the root causes of bearing issues before they escalate.
• 🔑 Primary stage failures in bearings can lead to secondary stage failures such as pitting and flaking, which are more noticeable and severe.
• 👀 It's important to inspect for signs of wear, corrosion, electrical damage, and misalignment to prevent bearing failure.
• 💡 Adequate lubrication is highlighted as a critical factor in preventing wear and other types of bearing damage.
• 🛑 Vibration, excessive internal clearance, and noise are indicators that a bearing may be failing and requires attention.
• 🛠️ Corrective actions for bearing issues include improving lubrication, addressing alignment, and avoiding direct hammer blows during assembly.
• 📘 The video script also mentions that the next lesson will cover sliding bearings, suggesting a continuation of the topic in subsequent training modules.

Q & A

What was covered in the previous teleaula regarding bearings?

The previous teleaula covered what a rolling bearing is, how to inspect bearings to detect problems as part of preventive maintenance, and how to properly disassemble and assemble bearings.

What are the primary causes of bearing failures discussed in the teleaula?

The primary causes of bearing failures include inadequate or insufficient lubrication, rough handling, improper mounting, and external factors such as electrical currents or vibrations.

How can inadequate lubrication affect bearings?

Inadequate lubrication can cause bearing surfaces to wear out, leading to a dull appearance, and in advanced stages, the surfaces may turn blue or brown due to excessive heat. This is because the lubricant loses its properties or becomes scarce.

What are the signs of bearing damage due to vibrations?

When bearings are exposed to vibrations, the raceways may develop bright depressions or oxidation marks. In roller bearings, these depressions appear as elongated marks, while in ball bearings, they are circular.

What is the recommended preventive maintenance for bearings exposed to vibrations?

The preventive maintenance includes identifying and eliminating the source of vibration in the mechanical assembly to prevent further damage to the bearings.

What kind of damage is caused by overloading or improper mounting of bearings?

Overloading or improper mounting can lead to indentations on the raceways, particularly when excessive pressure is applied during assembly or if the bearing seat shifts. This can also result in cracks or fractures.

What preventive measure should be taken during the assembly of bearings to avoid damage?

It is important to follow the manufacturer's instructions carefully, apply appropriate pressure during assembly, and avoid using excessive force, such as hammer blows directly on the bearing.

What is the difference between primary and secondary stage failures in bearings?

Primary stage failures include wear, indentations, scratches, corrosion, and electrical damage. Secondary stage failures, such as spalling and cracks, typically result from the progression of primary stage failures.

What causes corrosion in bearings, and how can it be prevented?

Corrosion in bearings is caused by exposure to moisture or corrosive substances over time. It can be prevented by using a lubricant that inhibits corrosion and ensuring proper sealing to keep moisture out.

How can electrical currents cause damage to bearings?

Electrical currents passing through bearings can cause dark brown or black streaks and crater-like formations on the raceways and rolling elements. Preventing this type of damage requires diverting the current away from the bearing, especially during welding operations.