ET 340 Test 1 Questions with Correct Answers

ET 340 Test 1 Questions with Correct Answers Fluid Delivery - Answer-Associated with the fluid output of a pump, determined by the size of the unit pumping chamber. Fixed-delivery pumps - Answer-Constant fluid output for each pump revolution. Variable-delivery pumps - Answer-Produce fluid output from zero, or no flow per revolution, to the maximum allowed by the size of the unit. Pump Design/Selection Factors - Answer-• Operating pressure • Flow requirements • Circuit cycle rate • Expected length of service • Environmental conditions • Cost Gear Pumps - Answer-Positive-displacement, rotary units Gear Pumps - Answer-One gear of the pumping mechanism is turned by the prime mover, the second gear serves as the driven gear. The unmeshing and meshing of the gear teeth as the gears rotate, results in the pumping mechanism. External-gear pumps - Answer-These have teeth on the outside of the rotating shafts. External-gear pumps - Answer-• Most popular in the hydraulic field. • Compared to other designs of similar displacement and operating characteristics, these are generally low cost. • Provide good life-expectancy, and stand up well when subjected to typical fluid contamination. • Available in pressures up to 3000 psi, and flow capacities up to 150 gpm. Internal-gear pumps - Answer-In this design one of the gears has external teeth and the other has internal teeth. Most common Internal-gear pump design. - Answer-Gerotor __________________ design is similar to the Gerotor, but the pumping chamber also has a fixed, ______________-shaped element. - Answer-Crescent Power Unit - Answer-Provides the energy for operation of the system, move the fluid through the system, and provide a safe maximum limit on system pressure while assisting in maintaining proper system operation temperature and fluid cleanliness. Coupler - Answer-In most HPS, the prime mover is mechanically ________________ directly to the input shaft of the system pump. Coupler - Answer-Used to maintain proper alignment between the input shaft and the system pump. Coupler - Answer-The _______________ ratings should match the rated speed, load, and allowable misalignment factors. Belt, chain, and gear coupler - Answer-These types of connections are less efficient, and have a lower safety factor, and place higher stress on the equipment. But, they may be required in situations where changing to a higher or lower speed is required. Positive-displacement pumps - Answer-Produce a constant output for each revolution of operation over a wide range of operating pressures. Positive-displacement pumps - Answer-They have very close tolerances between moving and stationary parts.