Download - DC-Motor Description & Maintenance
GPA 654 MDC-MOTORS
DESCRIPTION
DC- motors description 2
DC- motors description 3
Last revision: october 2008
Feed back requisted to:
DC- motors description 4
DC- motors description 5
How a Direct Current motors functions
DC- motors description 6
DC- motors have been used in industrial applications for years.Coupled with a DC-drive, DC motors provide very precise control.DC motor can be used with conveyors, elevators, extruders, marine propulsion, marine applications,….to name a few.
DC- motors are made up of several major components wich include the following:
•Frame
•Shaft
•Bearing
•Main field winding (Stator)
•Armature
•Commutator
•Brush assembly
Of these components, it is important to understand the electrical characteristics of the main field winding, know as the stator, and rotating winding know as the armature. An understanding of these two components will help with the understanding of various function of a DC-drive
(Rotor)
Construction:DC motors
DC- motors description 7
The relation ship of the electrical components of a DC motor is shown in the following illustration. Field winding are mounted on pole pieces to form electromagnets, in smaller DC motor the field may be a permanent magnet. However, in larger DC fields the fields typically an electomagnet. Field winding and pole pieces are bolted to the frame. The armature is supported by bearing and brackets. Carbon brushes are held against the commutator,
The armature rotates between the poles of the field winding. The armatures made up a shaft, core, armature winding, and a commutator. The armature windings are usually form wound and then placed in slots in the core.
BASIC CONSTRUCTION ARMATURE
DC- motors description 8
Brush
DC- motors description 9
Basic DC Motor Operation
Magnetic Fields
A DC motor rotates as a result of two magnetic fields interacting with each other. The first field is the main field that exists in the stator windings. The second field exists in the armature. Whenever is generated around the conductor.
DC- motors description 10
Right-HandRule for Motor
With LAPLACE rule: Armature rotate
Flux + current = rotating force
DC- motors description 11
CEMF Armature Field
DC- motors description 12
Position 3
Commutation
DC- motors description 13
DC-MOTOR YZC 800 DESCRIPTION
DC- motors description 14
YZC800 General description:
This manual is applicable for the marine electric motor YZC800.FL/FWS/FWS-1, which is mainly used for offshore supply-boats. The end-user shall observe the requirement in this manual to ensure the reliable operation of the motor.
All DC-motors are independent field excitation. One is the motor of horizontal-mounted structure (FWS), and the other has a vertical mounted structure (FL). They adopt forced air-cooling and positive explosive-proof lead box . The FL/FW motors are a single shaft extension, which is coupled with drive mechanism through a coupling. The FWS/FWS-1 motors are a double shaft. The motor is fitted with a blower; the cooling air goes inside from the commutator-end and goes outside the pinion end.
Between the commutator-end and lead connecting box, there is the explosive proof pipe installed, the high-pressure can be conducted into the lead connecting box and keep it in positive status.
The motor’s magnet frame is an octagon molded steel plate frame, which is a part of magnetic circuit and also it is the first component of the motor. There are three inspection windows at the commutator-end in order to replace brushes and do maintenance of commutator and brush holder systems. These inspection windows must be closed and proofed when the motor is operating.
Main field coils, commutating-coils and bearings are equipped with temperature sensor. Sensor wiring go into small explosive proof connecting box on frame by lead, on VMS displays end-user can check the temperature of above mentioned parts.
Pressure switches in lead box, in case blower fan wrong, the DC- motor will stop automatically. There is an assistant switch for emergency stop on the side of the lead box in case of necessary. Two 220V, 500W, 60Hz, single-phase heaters fitted at the bottom of commutator end to put through the power
supply when the motor stops operating to avoid the motor being affected by damp .Two G3/8”screw plug at the bottom of commutator end, when water built up inside the motor, open the plug to drain the water.
Changing the current flows through field-armature and field-wingding can control the torque of the motorChanging the current directions flowing through the main field can change rotating direction of the armature. Insulation level of the motor is class H, by using excellent insulation materials and varnishing by vacuum
pressure, it is sure that the motor is in perfect condition of insulation strength, mechanical strength, heat resistance, moisture proof and excellent conduciveness.
DC- motors description 15
trustherPropulsion/FIFI
counterclockwise&clockwiseCLOCKWISEROTATING DIRECTION
FORCED VENTILATION -6600m3/hFORCED VENTILATION -6600m3/hCOOLING
HHINSULATION CLASS ROTOR
HHINSULATION CLASS STATOR
≤ 120V≤ 150VEXCITING maximum VOLTAGE
45A60AMAXIMUM CURRENT EXCITING
85018Nm10055,5 NmMAXIMUM TORQUE
1200 A1600AMAXIMUM CURRENT
-7735NmRATED TORQUE
-1040 tr/mnRATED SPEED
950 A1185 ARATED CURRENT
0 to 600V0 to 750VRATED VOLTAGE
540 KW842 KWRATED POWER
INDEPENDANT EXCITATIONINDEPENDANT EXCITATIONCATEGORY
YZC 800FLYZC 800FL/FWMODEL
YZC 8000FL/FW
HI-TORQUE DC-MOTORS SPECIFICATIONS
DC- motors description 16
Horizontal double shaft.O use YZC800FWS-I
Horizontal double shaftYZC800FWS
Horizontal single shaftYZC800FW
Vertical DC-motorYZC800FL
YZC 800FL
GPA 654 M
YZC 800FL YZC 800FW
YZC 800FWS YZC 800FLYZC 800FWS-1
GPA 254
DC- motors description 17
Blower air Intake
480VAC blower motor
Lead connecting box
Brushes maintenance door
Tº Sensors connecting box
Shaft DC-MOTOR FL
DC- motors description 18
DC-motor with L-drive
Exaust blower flow
Maintenance window With CO2 pipe
Steering gear electric motor
Steering gear hydraulic motor
electric steering Oil pump
Intake blower flow
Sensors Tº connecting box
Note : Caution about vocabulary.
DC- motor is an electric Direct Current motor ( EPD)
L- drive is the kind of propulsion (STEERPROP)
DC- motors description 19
Steerprop:
steering-gear system
Berg: propeler system
L-DRIVE
DC- motors description 20
FRAME
FIELDS
BRUSH HOLDER & BRUSHES Commutator
DC-MOTOR COMPONENTS
ARMATURE WINDIND
SHAFT
DC- MOTOR
DC- motors description 21
FRAME
The motor’s magnet frame is an octagon molded steel plate frame, which is a part of magnetic circuit and also it is the first component of the motor. There are three inspection windows•Support for field•Support for bearings•Support for DC-motor equipment.
DC- motors description 22
Excitating coil unspark paint
FIELD: 8 excitating coils are fixed inside the frame.
4 main coils 2 north poles and 2 south poles create the flux
4 commutator coils for lower the commutation & raise magnetic capacity
Field before painting4 main coils
2 north & 2 souths in opposite position
4 commutator coils
2 north &2 south in opposit position
Main field coil before fitting
commutator field coilbefore fitting
FIELD
DC- motors description 23
To reach brushes and commutator open this door
To reach brushes and commutator open this door
To reach brush-older open thisdoor
BRUSH
DC- motors description 24
COMMUTATOR-END
The commutator is a vital part of every DC motor, it deserve the best os care. The fact that a commutator usually shows signs of distress before trouble actually occurs, is big help to the maintainer. If you can recognize these signs and know what to td, you can often correct the trouble before it becomes serious.
Function
A commutator has three functions:
1) It provides the required sliding electric contact between the fixed brushes and the moving armature to remove or apply electrical energy to the machine.
2) It act as a reversing switch as the ends of the armature coils pass the brush positions the commutator switches them from one circuit to another where the current is flowing in the opposite direction. Thus all the coils have current flowing through them in the proper direction at all time.
3) It also brings to the brush surface the voltage of each armature coil in the circuit. These voltages add up bar between brushes. As a result, the total operating voltage of the machine appears at the brushes
DC- motors description 25
DC. from SCR
DC voltage
0 to 750V
Rotating Force
clockwise
NORTH
SOUTH
With LAPLACE rule Armature turn :
Fluxe + current = rotating force
Right hand rule
Rotating Force
clockwise
Rotating Forces
clockwise
Brushes
DC- motors description 26
4 x 3 BRUSHES
BRUSH- HOLDER
brush caracteristics
T900 carbone/graphite
lents : 900mm
Use size max: 350mm
Cut angle: 50°et 60°
Contact area surface: minimum 80%
BRUSH-SPRING
The quality of the contact between brushes and commutator are paramount to preserve a good functionnality of DC motor.
DC- motors description 27
LEAD CONNECTING BOX
4 positive armature wires
From SCR cabinet
4 negative armature wires
From SCR cabinet
positive connection
negative connection
FIELD connection
sensors connections
DC- motors description 28
YZC 800 FW/FW-1 LEAD CONNECTING BOX
4 positive armature wires
From SCR cabinet
4 negative armature wires
From SCR cabinet
positive connection
Supply + brushes
negative connection
Supply -brushes
FIELD connection
sensors connections
DC- motors description 29
DC-MOTORS ALARMS
DC- motors description 30
All sensor’s paramaters from DC-motors are integrated in Power Management System (technosol)
Parameter DC-motor control
DC- motors description 31
Lock-out DC-motor Air cooling flow sensor DC-motor speed sensor
Temperature winding sensor
two in each coils
Temperature Bearing sensor
One for each Bearing
Greaser for Bearing
YZC800FW/FWS/FWS-1
DC-motor SENSORS
DC- motors description 32
DC-motors temperatures V M S control panel
commutator coils
Main field coils
Bearing
Bearing
Transformer winding
DC- motors description 33
100ºC90ºC110ºCbearing
165ºC155ºC18OºCRΩ=R0(1+a.t)Variation resistance fonctiontemperature
Commutator coil
165ºC155ºC185ºCRΩ=R0(1+a.t)Variation resistance fonctiontemperature
Main field coil
alarmPre-alarmPermissible temperature
rise (C)
Measure method
Parts of motor
Temperatures rated
DC- motors description 34
PRAMETERS DC-MOTOR CONTROL
VMS DISPLAY
DC- motors description 35
DC-MOTORS SCHEMATIC DRAWINGS
DC- motors description 36
FIRING PULSES FROM
SIEMENS SIMOREGDC-DRIVE
45 A
FIELD
CONTACTOR
FIELD
CONTACTOR
Twin reverse speeds contactors for bow thruster
BOW-THRUSTER
Field electric diagram
Φ
B
N
N
N
N
S
S
S
S
AMPMETER
AMPMETER-SHUNT
FUSES
Lead connecting box
DC- motors description 37
Φ
B
FIELD
CONTACTOR
DC-motors & fifi
Field electric diagram
N
S
S
S
S
N
N
N
FIRING PULSES FROM
SIEMENS SIMOREG
FUSES
60 A
AMPMETER
AMPMETER-SHUNT
Bridge rectifier
FIELD
TRANSFORMER 480V/190V
DC- motors description 38
DC-Drives
SCR Bridge
0V To 750V DC
600VAC 480VAC
DC-motors armature supply
TRANSFORMER 3 phases: 2 jobs:
1-increases AC voltage
2-lowers the armonicsDC Drive armature
480ACV
REACTOR 3 phases
- Lower the armomics
DC-Drives propulsion & FIFI
DC-DRIVE
560kW
DC-DRIVE
842kW
AFT & FWD BOW thrusters
0V To 600V DC
460ACV
DC- motors description 39
DC
-MO
TO
RS
MA
INT
EN
AN
CE
DC- motors description 40
DC- motors description 41
General description:
This m
anual is applicable for the marine electric m
otor YZ
C800.F
L/FW
S/F
WS
-1, w
hich is mainly used for offshore drilling transportation boat. T
he end-user shall observe the requirem
ent in this manual to ensure the reliable operation of the m
otor.A
ll DC
-motors are independent field excitation, an advantage to a separately
excited field is the stability of a variable speed to provide independent control of the armature and
field. One is the m
otor of horizontal-mounted structure (F
WS
), and the other has a vertical m
ounted structure (FL). T
hey adopt forced air-cooling and positive volt explosive-proof. The F
L/FW
m
otors are a single shaft extension, which is coupled w
ith drivem
echanism through a coupling.
The F
WS
-1 motors are a double shaft. T
he motor is equipped w
ith a blower; the cooling air goes
inside from the com
mutator end and goes outside the pinion end.
Betw
een the comm
utator end and connection box, there the explosive proof pipe installed, the high-pressure can be conducted into the connection box and keep the connection box in positive status.
The m
otor’s magnet fram
e is an octagon molded steel plate fram
e, which is a part
of magnetic circuit and also is a m
ain component of the m
otor. There are three inspection w
indows
at the comm
utator end in order to replace brushes and do maintenance of com
mutator and brush
holder systems. T
hese inspection window
s must be closed and proofed w
hen the motor is
operating.T
he field coil, comm
utating coil and bearings at both endsare equipped w
ith tem
perature sensor, which go into sm
all explosive proof connection box on frame by lead, in V
MS
displays end-user can know
the temperature of above m
entioned parts. T
here are pressure switches in lead box, once blow
er fan goes wrong, the m
otor will
stop automatically. T
here is an assistant switch for em
ergency stop on the side of the lead box in case of necessary.
Tw
o 220V, 500W
, 60Hz, single-phase heaters fitted at the bottom
of comm
utator end to put through the pow
er supply when the m
otor stops operating to avoid the motor being affected by
damp .T
wo G
3/8”screw plug at the bottom
of comm
utator end, when w
ater built upinside the
motor, open the plug to drain the w
ater.C
hanging the current flows through field arm
ature and fieldw
ingding can control the torque of the m
otor; changing the current directions flowing through thte
main field can change
rotating direction of the armature.
Insulation level of the motor is class H
, by using excellent insulation materials and
varnishing by vacuum
pressure, it is sure that the motor is in perfect condition of insulation strength,
mechanical strength, heat resistance, m
oisture proof and excellent conduciveness.
YZ
C800 F
L: Bow
-thruster
DC- motors description 42
2.1 Clean the shell after sw
itch off the power. T
ear down screen
cover; remove the dust by clean,
dry compressed air. It is necessary to keep interior of the m
otor clean.
NO
TE
: It is forbidden that blow interior of the m
otor with high-pressure air w
hen the motor
electrified. Wear protective clothing, gloves and eye patch to do clean w
ork, and comply w
ith relevant operating instructions.
2.2 Covers should be sm
ooth and complete, be inosculated w
ith the frame, rubber w
asher should be sealed com
pletely, and latches should be fastened.
2.3 clean dust, carbon powder and greasy dirt on insulting arm
of brush holder and Teflon band
with clean, non-cotton cloth to keep the surface clean. G
o over the surface of brush-holder stud, once the crack and burn w
ere found, replace imm
ediately. Check brush leads and clam
p bolts, if the bolts loose, clam
p to proper torque (reference to the torquevalue in part data). C
heck if the spring is flexible or rusted, spring pressure should w
ithin the range of specification. Check if the
brush box is damaged, any dam
aged brush box must be replaced. C
learance between brush box
and comm
utator should be in the range of specification.
NO
TE
: It is not allowed to contact brush holder or
replace brush when the m
otor is operating in order to prevent from
shock hurt.
2.4 Brushed in brush box should m
ove freely, the contacting area between brush and com
mutator
should not less than 80% of brush area; check brush pigtail, it should not be loose, the space
between brush pigtail and com
mutator riser should be kept to avoid scraping each other, m
ake sure the pigtail above the spring.
Brush trade m
ark is T900, m
ixed use of various brush brands are not allowed, because that
may affect the perform
ance of comm
utator. Brushes of one m
otor should be used with sam
e tradem
ark. Change the brushes that have the failure as w
orn to minim
um lim
it or cracked, brush pigtails looseness, color abnorm
ality and so on, note that replace all brushes at one time.
2.5 Com
mutator is a key com
ponent of DC
motor, w
hich should be maintained frequently. Inspect
comm
utator surface regularly, which should have an even and fluster brow
n film covered,
otherwise, the surface shall be repaired.
2.6 Clean poly T
eflon band (located on comm
utator pressing ring) with clean cloth, check if there
is a sign of break-through, makes sure the band w
raps firmly on com
mutator press ring.
2.7 Check if com
mutator riser is w
ell welded. O
nce welding splitis found, repair the ar
mature.
2.8 Check banding tape of arm
ature, if tail of the tape dispersed, loose or any other deterioration is found, then the arm
ature should be repaired.
2.9 Check if there is m
elt solder on steel banding wire at the side of pinion; if their is any solder be
swung to the field coil. R
epair the armature if these happen.
2.10 Wipe dow
n the arcs ring with clean cloth; check if it is d
amaged
by flashover.
2.11 Check appearance of field coil insulation for evidence of overheat.
2.12 Pow
er lead insulation should be well protected, term
inals should be fastened, and ground lead m
ust be firm.
2 Periodical inspection.
DC- motors description 43
SA
FE
TY
RU
LES
before DC
-motors
maintenance operations
1. SC
R breaker in M
.S.B
opened and locked.
3. For blow
use only 8 bars dry air compressed
4. blowing operator should w
ear eyepatch
and durtym
ask.
5. Tools w
ill be secure with a string to enter in the
comm
utator compartim
ent
2. Assistant sw
itch on for DC
-motor em
ergency stop.
DC- motors description 44
RE
PLA
CE
ME
NT
OF
BR
US
HE
S:
Disassem
bly
a. Loose bolts on brushes.b. Lift spring on brushes.c. T
ake out the brushes.d. B
low carbon dust w
ith dry pressure air.
NO
TE
:During operation, the operator should w
ear the protective clothing, glove, and eyeshade and com
ply with the rules.
Assem
bly a. A
ssemble new
brushes; ensure the brushes can move freely in brush
box.b. P
ress spring to the side of new brush carefully, itis incorrect to push
down the spring fast, because it m
ay damage the brush.
NO
TE
:Brushes m
ust be specified; it is not allowed that use brushes in
different types. Replace w
hole set brushes in one motor, or reversing
performance and brush life m
ay be affected. When assem
ble the brushes, brush pigtail should be above the spring, or brush pigtail m
ay be damaged.
c. Screw
down the connection bolts, torque value shallcom
ply with
20±3N,m
ake sure that pigtail above the spring and keep away from
com
mutator surface for a certain distance, can’t be scraped each other.
d. Check spring pressure, w
hich shall comply w
ith 40±4N.
e. Check and screw
down all brush holders connection
f. Rub brushes w
ith glass sand paper, the contact area between
brush and comm
utator should not be less than 80% of brush area.
g. Run the m
otor; inspect operating status of new brushes.
NO
TE
:Em
ery paper is prohibited.
DC- motors description 45
Slide caliper
Max 900m
mM
ini: 550mm
2 bolts
Brushes-H
older
characteristics of brushT
900 carbon/graphitelength : 900m
mU
se size max: 350m
mC
ut angle: 50°et 60°C
ontact area surface: minim
um 80%
3 springs
DC- motors description 46
If the motor appear the failures as follow
s, which should be returned to
manufacturer for repairing w
ithin warranty period, out of the w
arranty period, the m
otor should be returned to manufacture or special plant for
repairing.
a)If m
otor can’t run normally because of com
mutator surface abrasion or burnt.
b) The depth of the slot on com
mutator surface less than 0.9m
m.
c) The m
ica undercutting depth on the comm
utator less than 1mm
.
The depth m
inimum
of the mica
between bars is 1m
m.
Com
mutator m
aintenance:
Keep com
mutator surface clean m
ake. Wipe the surface w
ith a clean cloth with
alcohol if there is oil dust and light burnt mark on com
mutator surface.
If there is obvious burnt mark on com
mutator surface and it can’t be w
iped down by
clean cloth, deal with com
mutator surface w
ith 00# glass emery cloth per follow
ing steps:
NO
TE
:It is forbidden to abrade com
mutator by carborundum
sand cloth,because friction practical m
ay scrap comm
utator surface, and also may adhere in
comm
utator bars and then affect reversing direction. When blow
the motor w
ith pressed air, operator should w
ear protective clothing, gloves and eye patch, and com
ply with the operating instructions
DC- motors description 47
Lead mark of pow
er connection box for the motor
Arm
ature and comm
utator end winding: A
1 A2
Main field w
inding: S
1 S2
A1
A2
S1
S2
Lead box Lead box
Insulation resistance test
Insulating resistance should be tested periodically, measure m
ain field, com
mutator field, arm
ature winding resistance to the ground and insulating
resistance between each other w
ith 1000V m
ega meter, it should not less than
5M
. Hi-pot test applied for 1m
in on every winding and brush holder w
ith50H
Z,
2500V sinusoidal current, should not have the sign of breakdow
n and flashover. H
umidity, dust and carbon pow
der may affect the reading of m
egs measurem
ent, so w
hen the reading is on the low side, cleaning and drying the parts. If the reading is
still low, then the m
otor needs to be disassembled for inspecting.
DC- motors description 48
Lead mark of tem
perature sensor in signal connection box for motor
Main field coil 1 1,2,3,4
Main field coil 2 5,6,7,8
Com
mutator coil 1 9,10,11,12
Com
mutator coil 2 13,14,15,16
Com
mutator end bearing 17,18,19,20
Shaft extension bearing 21,22,23,24
Connect to ground 32
Spare term
inal 25,26,27,28,29,30,31
Pressure sw
itch: 1, 2 normally open (2 and 3 connect perm
anently)
Assistant sw
itch: 3. 4 normally close
Heater : 16.17.18.19
480AC
V blow
er motor 8,9,10
To earth: 20
Spare term
inals: 5.6.7.11.12.13.14.15
DC- motors description 49
Hum
idity, dust and carbon powder m
ay be affecting the reader of megs
measurem
ent, so DC
-motor m
ust be cleaning and drying with air pressure.
the periods during which D
C-m
otors are stopped the heating must be put in
function, thus moisture creates by condensation does not low
er and prevent electric insulation.
Insulating resistance should be tested periodically (see schedule table), with
1000V m
ega meter
-1) m
easure main field, resistance to the ground
-2) com
mutator field, resistance to the ground
It should not less than 5MΩ
.
-3) m
easure resistance between m
ain field & arm
ature.
-4) m
easure the armature resistance value
1,50Ω
-5) m
easure the field resistance value 0,50
Ω
Mega-tester
2Gohm
s.1000V
11 2233 2415
NO
TE
!:Insulation m
easurements above take in count the electric cables supply.
In the event of lower m
easurements than the specifications, insulation m
ust be m
easure again after disconnection of the 10 cables of powers.
If the reading is still low, then, the D
C-
motor needs to be check by E
lectrician specialist or disassem
bled for inspecting.
DC- motors description 50
Arm
ature bearing lubrication
DC
-motors assem
bled without greaser-nose
Arm
ature bearing must be greased before assem
bly. During a period of
overhaul about 2 years, adding grease is not allowed.
At overhauling tim
e, bearings can be cleaned, checked, and greased. Volum
e of lubrication is 1.531kg.
DC
-motors assem
bled with greaser-nose
Bearing
must be to lubricate periodically according to the num
ber operating hour. (see schedule table).
NO
TE
!:S
uper greasing is harmful it involves a too great quantity of grease and of this fact
the bearing enters in overheating quickly.SH
ELL
D6 A
2 G0
FA
GA
RC
AN
OL L135V
BR
AN
DB
earing type grease
Aft bearing
Forw
ard bearing
DC- motors description 51
1300±65(N
.m)
700±36 (N
.m)
340±24 (N
.m)
300±20(N
.m)
155±15(N
.m)
20±3(N
.m)
20±3(N
.m)
20±3(N
.m)
7±1(N
.m)
Fastening
torque (N.m
)
M33
M24
M22
M20
M16
M12
M10
M8
M6
Bolt
diameter
Note:
A bolt
over tightening can damage the filtage
definitively and create a hot spot at the tim
e of the passage of the current.
PE
RIO
DIC
AL IN
SP
EC
TIO
N:
Bolt fasting torque: (N
.m)
6000-R
emove and clean fan blades and housing.
In addition to items 1-2-3
Blow
er4
3000-
Each com
mutator bar m
ust be check and clean with
ethanol and no-cotton cloth(see page 3 m
aintenance manual)
-Check blow
er pressure contactor-T
est emergency contact
-Add bearing grease
In addition to items 1-2
Coils
Field
Com
mutator
brushes
3
1400-B
low out inside connecting box
-check alls terminal connections for tightness
-measure the length and check each brushes
-Test insulation resistance.
In addition to item 1
Control connecting box
2
700B
low out w
ith clean dry compressed air. Inspect
brushes , brush-holders, spring pressure, comm
utator and leads.
Com
mutator B
rushes olderS
pring brush
1
INT
ER
VA
L(hours)
PR
OC
ED
UR
EE
QU
IPE
ME
NT