Module 9

Question 1

a motor that converts the movement and pressure of hydraulic fluid into the energy of a rotating shaft

Answer 1

Hydraulic motor

Question 2

a motor that has a mechanical seal between the inlet and outlet ports

Answer 2

Positive-displacement motor

Question 3

the range of operating pressures from the minimum needed to turn a hydraulic motor to the maximum the motor can withstand without suffering damage.

Answer 3

Pressure range

Question 4

the twisting effect that causes a piece of equipment to rotate

Answer 4

Torque

Question 5

All hydraulic motors have _____ displacement.

Answer 5

Positive

Question 6

The shaft speed of a fixed, positive-displacement motor can be changed by varying the _____ of the hydraulic fluid.

Answer 6

Flow rate

Question 7

The pressure range for most hydraulic motors varies from _____ to _____ psi.

Answer 7

100; 5000

Question 8

Name the three kinds of motor torque.

Answer 8

Starting torque
Running torque
Stalling torque

Question 9

When selecting a replacement motor for a system, always make sure it is compatible with the system’s _____.

Answer 9

Fluid

Question 10

The service life of a hydraulic motor is measured in _____.

Answer 10

Hours

Question 11

A hydraulic motor functions by changing the volume of its ____.

Answer 11

Fluid chamber

Question 12

As fluid under pressure moves through the motor, its moving energy is transferred to the _____ of the motor.

Answer 12

Revolving shaft

Question 13

Rotation in an internal gear motor is caused by fluid pressure acting on the _____.

Answer 13

Gear teeth

Question 14

Gear motors may be supplied with _____ plates to help maintain the pressure and reduce internal leaks.

Answer 14

End or Wear

Question 15

A vane motor made with two motor chambers is called a(n) _____ motor.

Answer 15

Balanced

Question 16

A vane motor with a movable cam ring has a _____ displacement.

Answer 16

Variable

Question 17

Variable-displacement vane motors have higher internal _____ than fixed-displacement motors.

Answer 17

Slippage

Question 18

The reciprocating motion of an axial-piston motor is converted to rotary motion by the _____.

Answer 18

Cam Plate

Question 19

For axial-piston motors, displacement is adjusted by changing the angle of the _____.

Answer 19

Swash Plate

Question 20

Rotary actuators move in an arc that is less than a full _____.

Answer 20

Revolution

Question 21

The speed of a hydraulic motor is determined by the fluid’s

Answer 21

Flow rate

Question 22

All hydraulic motors are _____ motors.

Answer 22

Positive-displacement

Question 23

The maximum fluid pressure that a motor can withstand is defined by

Answer 23

Its pressure range.

Question 24

The force exerted by a hydraulic motor while operating normally is called

Answer 24

Running torque

Question 25

When a new hydraulic motor is installed in an existing system, its compatibility must be checked against all of the following except the

a. effect the fluid has on the seals
b. fluid’s resistance to foaming
c. fluid’s viscosity index
d. piping material

Answer 25

d. Piping material

Question 26

The service life of a hydraulic motor is given in

Answer 26

Hours of operation

Question 27

The pressure of the hydraulic fluid entering an internal gear motor acts on the

Answer 27

Gear teeth

Question 28

Gear motors are frequently equipped with wear plates to prevent

Answer 28

Internal leakage.

Question 29

Which of the following characteristics applies to variable-displacement hydraulic motors?

a. balanced design
b. compact size
c. economical operation
d. high slippage rates

Answer 29

d. High slippage rates.

Question 30

How far can vane-type rotary actuators rotate?

Answer 30

Just under one revolution.