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MT 108 Chapter 3 > Module 4 > Flashcards

Flashcards in Module 4 Deck (29):
1

the device used in a hydraulic system to convert mechanical energy into hydraulic energy

Pump

2

the ratio of a pump's actual delivery rate to its theoretical displacement

Volumetric efficiency

3

the ratio of a pump's hydraulic power output to its mechanical power input

Overall efficiency

4

A hydraulic pump converts _____ energy into _____ energy.

Mechanical; Hydraulic

5

Pumps classified by their principle of operation include _____ and _____ types.

Positive-displacement; Nonpositive-displacement

6

Positive-displacement pumps have either a(n) _____ or _____ displacement.

Fixed; Variable

7

Fixed-displacement pumps are _____ efficient than variable-displacement pumps.

More

8

The delivery rate or flow rate of a pump is commonly referred to as its _____.

Capacity

9

To prevent overheating and internal slippage, a high-pressure pump is limited to a minimum operating _____.

Speed

10

Name the two ways in which pump efficiency is described.

Volumetric; Overall

11

The service life of a pump is specified in terms of operating _____.

Hours

12

External gear pumps can operate at pressures of up to _____ psi.

3000

13

Internal gear pumps are used in hydraulic systems that have _____ speeds and _____ capacities.

Low; Small

14

Gerotor pumps are made without an internal gear _____.

Separator

15

A vane pump in which the rotor is placed off-center is said to be _____.

Unbalanced

16

Pump vanes that are not spring-loaded are held in contact with the housing by both centrifugal and _____ pressure.

Fluid

17

The fluid flow in a variable-displacement vane pump is changed by moving the _____.

Cam Ring

18

The two most common types of piston pumps are _____ and _____ pumps.

Axial-Piston; Radial-Piston

19

Can piston pumps operate at flow rates over 1000 gym?

Yes

20

A hydraulic pump does all of the following except
a. convert mechanical energy into hydraulic energy
b. create a partial vacuum at the inlet
c. deliver the fluid to the outlet
d. produce the working pressure in the system

d. Produce the working pressure in the system.

21

Which of the following types of pumps is not a positive-displacement pump?
a. Centrifugal
b. Gear
c. Impeller
d. Vane

a. Centrifugal

22

The volume of delivery of a fixed-displacement pump
a. can be changed by changing the physical arrangement of the pumping mechanism
b. can be changed by changing the pump's speed
c. cannot be changed
d. changes with variations in system pressure

b. Can be changed by changing the pump's speed.

23

The capacity of a pump may be specified in all of the following except
a. cubic inches per minute
b. cubic inches per revolution
c. gallons per minute
d. pounds per square inch

d. Pounds per square inch.

24

The efficient operating life of a pump is usually given in terms of
a. days
b. flow rate
c. fluid pressure
d. hours

d. Hours.

25

Because of their design, internal gear pumps are limited to applications having
a. low pressures and high speed
b. low speeds and high pressures
c. small capacities and high speeds
d. small capacities and low pressures

d. Small capacities and low pressures.

26

A vane pump of the unbalanced design can be identified by its
a. counterweights
b. dual inlet ports
c. off-center rotor
d. special drive motor

c. Off-center rotor.

27

The vane tips of a vane pump are usually grooved or split to permit all of the following except
a. a larger contact area at the housing
b. better lubrication
c. free movement of the vanes
d. longer vane life

a. A larger contact area to the housing.

28

Variable-displacement vane pumps control fluid flow by
a. changing the discharge port
b. changing the inlet port
c. shifting the cam ring
d. shifting the housing

c. Shifting the cam ring.

29

Radial-piston pumps are generally designed and manufactured with a
a. bent shaft
b. double check valve
c. rotating or stationary block
d. straight shaft

c. Rotating or stationary block.