hydraulic motor

Question 1

the greater the inlet flow rate supplied to a motor

Answer 1

the faster the drive shaft will turn

Question 2

the amount of inlet pressure in a motor is determined by

Answer 2

the amount of resistance on a motor drive shaft

Question 3

are motors able to convert all hydraulic energy into mechanical energy

Answer 3

no some energy is lost due to leakage and friction within the motor

Question 4

as leakage and frictional losses increases in a motor

Answer 4

the overall efficiency of the motor decreases

Question 5

why is internal leakage needed on a hydraulic motor

Answer 5

for lubrication and cooling of moving parts

Question 6

what happens to leakage oil in a hydraulic motor

Answer 6

it is externally drained out through a drain line

Question 7

what is the basic configuration of a external gear motor

Answer 7

two gears in mesh . one is connected to the drive shaft and the other is an idler .

Question 8

if you were to revers the flow of oil in an eternal gear motor what would happen

Answer 8

the inlet port would become the outlet and the rotation of the drive shaft would change

Question 9

why are external gear motors poor torque generators

Answer 9

because the surface area of only one tooth on each gear is providing torque and the surface area of that tooth is very small . also they are unbalanced in design not allowing high working pressures

Question 10

in a gerotor and geroller motor what component rotates around the stationary internal lobe gear

Answer 10

the geroter star or geroller star

Question 11

in order to produce one revolution of the output shaft of a orbital motor all six lobes of the motor would be exposed to oil how many times

Answer 11

7 ( the number of valleys in the internal gear )

Question 12

what is the advantage of having internal gear lobes that roll in a geroller motor

Answer 12

provide better wear and less internal resistance

Question 13

what is an advantage of having a disc valve in a geroller motor

Answer 13

the disc valve is more compact allowing the whole motor to be smaller in design

Question 14

the vast majority of vane motors are

Answer 14

balanced because balanced vane motors can be operated at a higher pressure then unbalanced

Question 15

why do vane motors use springs acting on the underside of the vanes in the rotor

Answer 15

to make sure the vanes have good contact to the cam ring on start up of the motor

Question 16

on a balanced vane motor where are the inlet ports and outlet ports located

Answer 16

180 degrees apart from each other

Question 17

what do the pressure plates in the vane motor provide

Answer 17

they keep internal clearances to a minimum minimizing internal leakage

Question 18

why are balanced vane motors considered to be better torque generators then gear motors

Answer 18

they are more volumetrically efficient and their balanced design allows them to operate at a higher pressure than gear motors

Question 19

are piston motors are the most efficient type of hydraulic motor and are also capable of generating the highest rpm

Answer 19

yes

Question 20

what dose it mean to have a fixed displacement motor

Answer 20

motor rpm is directly proportional to the flow rate supplied to the motor . torque generation is directly proportional to the pressure applied to the motor

Question 21

on a variable displacement piston motor changing the swash plate angle will result in

Answer 21

different rpm and torque characteristics of the motor

Question 22

the cylinder barrel and pistons of a piston motor are often referred to as the

Answer 22

rotating group

Question 23

what component varies the motor displacement by changing the swash plate angle on a variable displacement piston motor

Answer 23

the servo piston

Question 24

stops on a variable axial piston motor prevent the swash plate from moving beyond a range of

Answer 24

6.5 to 19 degrees from perpendicular

Question 25

why can a swash plate of a variable displacement piston motor never reach perpendicular

Answer 25

because the circuit would be hydrostatically locked and the motor would freewheel (stall)

Question 26

what does it mean to have a pressure compensated motor

Answer 26

the motor automatically changes its displacement depending on the load applied to the output shaft

Question 27

when no load is acting on the compensator spool of the pressure compensated piston motor what angle is the swash plate at

Answer 27

minimum angle for maximum rpm

Question 28

what happens when pressure at the inlet port of a pressure compensated piston motor is great enough to overcome the compensator spring

Answer 28

the spool moves up in its bore allowing system pressure to act on the actuating piston . force created by the piston pushes the yoke to maximum displacement resulting in maximum displacement reducing speed and increasing torque

Question 29

why is it an advantage to have the pistons fitted into sockets of the flange plate of an bent axial piston motor

Answer 29

because they are stronger and are not vulnerable to contamination and cavitation like axial piston motors whose shoes must slide across a stationary swash plate

Question 30

what determines the displacement of the bent axial motor

Answer 30

the angle of the cylinder block to the drive shaft

Question 31

on a variable displacement axial piston motor what alters he angle of the cylinder block in relation to the drive shaft of the motor changing the displacement

Answer 31

servo pistons controlled by a displacement control valve

Question 32

radial piston motors are suitable for applications where

Answer 32

low rpm and high torque are required

Question 33

on a radial crankshaft piston motor how are the pistons balanced from thrust forces acting on them

Answer 33

pressurized oil passes through the piston and works on the contact surface of the connecting rod and crankshaft lubricating and opposing the thrust force acting on the piston

Question 34

what supplies oil to the inlet ports and allows outlet oil to return to tank on a radial crankshaft operated motor

Answer 34

spool valve . as the spool valve rotates with the motor output shaft ports are uncovered ensuring pressurized oil is supplied to each of the pistons and return oil is directed to the oil reservoir when the pistons are at the proper stroke