CHAPTER 6 PRIME MOVERS, PUMPS, AND AIR COMPRESSORS

LEARNING OBJECTIVE: Identify types and uses of prime movers, pumps, and air compressors; identify procedures required in preventive maintenance and maintenance on pumps and air compressors.

Because of the many types of prime movers, pumps, and air compressors used by Navy units, the information presented on operating procedures and maintenance requirements in this chapter is brief and general. The emphasis is on fundamental operating principles, parts, and maintenance of prime movers, pumps, and air compressors, and operating problems you may experience.

Local commands develop specific operator maintenance schedules, logs, and reports. Each local command also maintains a file of manufacturer's instructions, parts lists, drawings, and diagrams for all equipment installed or used in that command. Taken together, these maintenance schedules, manufacturer's instructions, and so on, provide you with detailed information on operating procedures and maintenance requirements. Always get to know these guides before attempting to operate and maintain the equipment for which you are responsible.

There are several important Navy training publications of which you need to be aware. Although these books are described as basic texts, the information they contain can help you better understand the equipment covered in this chapter. To learn more about the operating principles and construction of electric motors, you should obtain a copy of each of the following TRAMANs:

Module 5, Introduction to Generators and Motors, Navy Electricity and Electronics Training Series (NEETS), NAVEDTRA B72-05-00-96.

Basic Machines, NAVEDTRA 12199, explains the operating principles and construction of internal combustion engines.

Fluid Power, NAVEDTRA 12966, discusses fluid physics, construction, and operating principles of pumps and air compressors, valves, packing, pressure gauges, and fluid piping, tubing, and temperature.

PRIME MOVERS

LEARNING OBJECTIVE: Identify the basic types, the operation, and the maintenance of prime movers.

Prime movers are often called "driving equipment" because they are the primary source of mechanical energy or power. The mechanical energy produced by the prime mover is transmitted to another machine or mechanism, such as a pump or air compressor, to do some form of useful work. The mechanism, or linkage, that transmits the mechanical power developed by the prime mover is called the drive.

Electric motors and internal combustion engines are commonly used as prime movers. For this reason, this chapter briefly covers electric prime movers, gasoline-operated prime movers, and diesel-operated prime movers.

ELECTRIC MOTORS

As prime movers, electric motors receive electrical energy from some external source and transform it into the mechanical energy needed to produce work. Electric motors are either direct current (dc) or alternating current (ac). Because most of the electrical power generating systems that Seabees come in contact with produces alternating current, only the ac motor will be discussed.

Induction AC Motor

Of the various types of ac motors available, you will work primarily with the rotating-field INDUCTION ac motor. The popularity of this motor is