Series 300: Mechanical Systems

Course 304: Bearings

Covers principles and applications of various types of bearings, including plain journal, ball, and roller bearings. Explains installation, inspection and repair of bearings. Deals with specialized bearings, including powdered-metal, nonmetallic, and hydrostatic bearings. Covers bearing seals, lubrication, and maintenance practices.

Lesson 1 - Bearings and Shafts

Topics:

Bearing classification and selection; Shaft materials and stresses; Vibration; Critical speed; Fits and clearances

Learning Objectives:

• Name the two main categories of bearings and cite their advantages.
• Identify bearings by the kind of support they provide.
• Describe the three kinds of stresses acting on shafts.
• Explain natural frequency of vibration and critical speed.
• Name and describe three classes of fits.

Lesson 2 - Plain Journal Bearings I

Topics:

Features, types, and advantages; Lubrication; Lubricating grooves; Seals; Split bearings; Bearing design; selection

Learning Objectives:

• Explain the function of lubricating grooves.
• State two reasons for using seals on plain bearings.
• Name the principal types of plain journal bearings.
• Describe the structure of two kinds of precision inserts.
• Define crush and spread.

Lesson 3 - Plain Journal Bearings II

Topics:

Materials; Score resistance; Load capacity; Fatigue strength; Conformability; Embeddability; Corrosion and temperature resistance; Relining

Learning Objectives:

• Name and explain the characteristics that are most important in materials for bearings.
• State advantages and disadvantages of the standard types of bearing materials.
• Describe standard practices for inspecting bearings.
• Explain bearing repair procedures.

Lesson 4 - Antifriction Bearings I

Topics:

Operating principles; Bearing and cage materials; Lubrication; Seals and shields; Tolerances; Fits; Standard and precision bearings; Running accuracy

Learning Objectives:

• Identify the functions of the various parts of a typical rolling-element bearing.
• Explain the three elements of the AFBMA code.
• Define the categories of tolerances for ball bearings.
• Describe the factors that influence running accuracy of bearings.

Lesson 5 - Antifriction Bearings II

Topics:

Environment; Mounting; Radial and axial clearance; Fixed and floating bearings; Fits; Alignment; Mounting methods; Selection

Learning Objectives:

• Name the factors that must be considered in the design of antifriction bearings.
• Describe the process of checking adequate running clearances for bearings.
• Explain the reasons for using fixed and floating bearings together.
• Describe the common methods of mounting bearings.

Lesson 6 - Ball and Roller Bearings

Topics:

Ball and roller bearing design; Single-row radial, single- and double-row angular contact bearings; Two-piece, inner-ring bearings; Roller bearings

Learning Objectives:

• Name the three basic ball bearing designs and describe their characteristics.
• Explain the purposes served by the basic roller bearing shapes and their variations in typical applications.

Lesson 7 - Specialized Bearings

Topics:

Thrust, self-aligning, linear-motion, mounted, instrument, ungrounded ball, powdered-metal, nonmetallic, and hydrostatic bearings

Learning Objectives:

• Identify ten specialized bearings.
• Describe a specific function or application of each of these bearing types.

Lesson 8 - Bearing Seals

Topics:

Seal functions; Terminology and classifications; Labyrinth seals; Special seals; Selection and application; Seal materials; Mechanical seals

Learning Objectives:

• Identify the functions of bearing seals.
• Describe the construction and operation of labyrinth and oil seals.
• Explain the two classification systems for oil seals.
• Name typical applications for the different kinds of seals.

Lesson 9 - Lubrication

Topics:

Lubrication practices and equipment; Oil and grease lubrication; Packing; Manual, natural, and automatic lubrication devices and systems

Learning Objectives:

• State typical applications for oil lubrication of bearings.
• Detail the cleaning procedures for different oil lubrication systems.
• Discuss the three qualities that are the bases for selecting a grease lubricant.
• Give five easy rules for lubricating bearings.

Lesson 10 - Bearing Maintenance

Topics:

Maintenance, cleaning, and installation; Mounting and removing bearings; Loading patterns; Failure terminology

Learning Objectives:

• Identify a principal cause of early bearing failure.
• Describe installation procedures for antifriction and plain journal bearings.
• Name the different types of bearing failure and their causes.
• Tell how bearings should be cleaned and lubricated after inspection.