Course 303.1: Power Transmission Equipment

Covers belt drives, chain drives, gears and gear drives, adjustable-speed drives, shaft alignment, shaft coupling devices, and clutches and brakes.

Lesson 1 - Belt Drives

Topics:

V-belts; Timing and flat belts; Sheaves; Pulleys; Installation

Learning Objectives:

• List the factors that affect the power transmitted by a belt drive.
• Name the main components of a belt drive.
• List the standard V-belt designations.
• Explain the reason for using group belts.
• Describe installation and replacement procedures for V-belts

Lesson 2 - Chain Drives

Topics:

Terminology; Roller, double-pitch, leaf, and silent chains; Cast drive chains; Sprockets; Installation

Learning Objectives:

• Explain the differences between chain drives and belt drives in transmitting power.
• Explain how a roller chain drive works.
• Describe the construction of offset roller chain.
• Explain the differences between sprocket types A, B, and C.
• List the steps in installing a chain drive.

Lesson 3 - Gears

Topics:

Gear definitions and drives; Tooth contour and diametral pitch; Spur, helical, single-, double-cut, herringbone, bevel, and worm gears; Maintenance

Learning Objectives:

• Define the following terms used to describe gear drives: pitch circle, pitch diameter, working depth, tooth face, tooth flank.
• Calculate the diametral pitch of a gear.
• List advantages and disadvantages of helical gears.
• Explain the differences between herringbone gears and double-cut helical gears.
• Define the following terms used in discussing worm gears: worm lead, worm lead angle, normal worm pitch, worm axial pitch.

Lesson 4 - Gear Drives

Topics:

Shaft-mounted, worm-gear drives; Miter-gear boxes; Gear drive installation, maintenance, and definitions; Concentric, parallel, right-angle, vertical-shaft gear drives

Learning Objectives:

• Explain how additional speed reduction can be obtained with shaft-mounted gear drives.
• Describe a worm-gear drive and a miter-gear box.
• Give a general explanation of gear drive installation and maintenance.
• Define mechanical power, thermal power, and overload capacity.
• Explain what determines the service factor of a gear drive.
• Describe a concentric-shaft gear drive and a right-angle-shaft gear drive.
• Explain how parallel-shaft gear drives are lubricated.

Lesson 5 - Adjustable-Speed Drives

Topics:

Belt- and disk-type adjustable-speed drives, Roller-type, hydraulic, and electric adjustable-speed drives

Learning Objectives:

• Identify the main criteria for selecting adjustable-speed drives for industrial plants.
• Explain the operation of a variable-speed belt drive.
• Describe how to control variable-speed drives.
• Describe the belts and chains used for variable-speed drives.
• Explain the operation of a roller-type variable-speed drive.

Lesson 6 - Shaft Alignment

Topics:

Geometry of shaft alignment; Preparation; Reverse-indicator method; Aligning multiple machines; Face-rim, long-span, and laser alignment

Learning Objectives:

• Determine the corrections needed to align two machines, using the reverse-indicator method.
• Determine the corrections needed to align two machines, using the face-rim indicator method.
• Determine the corrections needed to align three machines on a common centerline.
• Determine the corrections needed to align two machines separated by a long floating shaft.
• State at least three advantages of using laser alignment equipment over using dial indicators.

Lesson 7 - Shaft Coupling Devices

Topics:

Solid, jaw, molded-rubber, chain, gear, metal-disk, shear-pin, torque-limiting, brake-wheel, floating-shaft, spacer, insulated, and other couplings

Learning Objectives:

• List three functions usually performed by a coupling.
• Describe two types of jaw couplings.
• Name an application for molded rubber couplings.
• State an advantage of chain couplings.
• Explain the operation of a shear pin coupling.
• Describe a torque limiting coupling.
• Name an application that involves a floating shaft.
• Describe a limited end float coupling.
• List advantages and disadvantages of spacer couplings.

Lesson 8 - Clutches and Brakes

Topics:

Jaw, friction, torque-limiting, tooth-type, centrifugal-type, overrunning, electric, and fluid clutches; Friction shoe, disk, electric brakes

Learning Objectives:

• Explain the purposes of a clutch.
• Describe the operation of a friction clutch.
• Explain the need for overrunning clutches.
• Name at least one application for an electric clutch.
• Explain how a fluid clutch works.