Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BV234 > Drive System > Flashcards

Drive System Flashcards

1
Q

General

A

Consists of:

  1. Engine transmissions
  2. Combining transmission
  3. Forward transmission
  4. Aft transmission

Primary function is to transmit engine output to rotor system. Secondary function is to drive AC generators, hydraulic pumps, transmission oil pumps, tach gen, and transmission oil cooler fan

Engine shafts to c box, 7 sync shafts from c box to forward transmission, 2 sync shaft from c box to aft transmission, vert shaft from aft transmission to aft rotor head, fan drive shaft, cooling fan, and rotor brake near c box

Each transmission has a separate primary and auxiliary lube system with sensors to detect temp, pressure, and metallic chips

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Engine Drive Shafting

A

Connects output of engine to input pinion of c box

Each shaft made of aluminum tubing with each end connected with a flex coupling to compensate for minor misalignment

Both shafts are serial numbered and dynamically balanced

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Aft Synch Drive Shafting

A

Connects aft output of c box to input pinion of aft transmission

2 shafts connecting with Thomas couplings and mounted to fuselage with lord mounts

Aft sync shafting is supported by a single bearing

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Forward Synch Drive Shafting

A

7 shafts connecting forward output of c box to input pinion of forward transmission

Forward 6 Synch shafts are identical and interchangeable, 7th shaft is unique in that it doesn’t have a bearing and support assembly attached to it

All 7 shafts are interconnected with Thomas couplings and aluminum adaptors mounted to each end

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Fan Drive Shafting

A

Transmits torque from aft transmission to transmission oil cooling fan

Extends diagonally up and forward from aft transmission at approximately a 45* angle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Aft Vertical Drive Shaft

A

Extends upward from aft transmission through aft pylon to aft rotor head. Shaft is splined to aft transmission output and is secured to airframe via thrust bearing

Each end of shaft is made of steel and pinned to carbon fiber center section

Center of rotor head is splined to aft vert shaft on the top

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Aft Vert Shaft Thrust Bearing

A

Connects aft vert shaft with aft pylon structure

Distributes lift force from aft rotor system to airframe instead of aft transmission

Bearing assembly is pressure lubricated with oil from aft transmission lube system, and the oil return line contains a screen and chip detector

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Transmission Oil Temp Indicating System

A

Consists of 5 temp bulbs, selector switch, and gauge

Each temp sensor from its corresponding input transistor is applied to logic circuit which is controlled by the selector switch. When switch is set to TEST, the output of the logic circuit is 0 volts, resulting in a 0 degree indication

When selector is set to SCAN the logic circuit compares the 5 temp signals and selects the highest reading

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Transmission Oil Temp Warning System

A

5 thermal switches warn pilot of overtemp condition when transmission oil temp increases above 140*C, illuminating common XMSN OIL HOT. The switch is located in line just prior to their respective coolers

2 thermal switches monitor oil temp in sumps of No. 1 and 2 engine transmissions. They closes on temp above 207*C and light their associated annunciator (ENG # XMSN HOT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Transmission Oil Pressure Indicating System

A

Consists of 5 transmission pressure transducers, switch assemblies, selector switch, and indicator dial

Logic circuit controlled by selector switch indicates pressure of transmission selected, and when set to SCAN it compares 5 pressure signals and selects the lowest pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Transmission Oil Pressure Warning System

A

5 identical oil pressure switches provide warning for underpressure condition. Contacts close on decreasing oil pressure below 18psig

When oil pressure drops below 18psig the associated pressure switch illuminates XMSN OIL PRESS light

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Engine Transmissions

A

Mounted on front of engine, takes N2 output power from quill shaft and changes its direction 90 degrees to go into c box

Sprag clutch on output shaft permits freewheeling if Nr exceeds N2

Engine is lubricated from main and auxiliary oil pumps located in c box. Scavenge pump located on c box returns oil to its reservoir

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Combining Transmission

A

Combines torque from both engine transmissions and changes its direction 90 degrees, distributing the power to output shafts to drive forward and aft transmissions.

3 section oil tank with common filler port provides primary and auxiliary lubrication for c box and engine transmissions. Accessory drive spur gear on forward output shaft provides drive for 6 element pump for 3 main oil pumps and 3 scavenge oil pumps. Auxiliary lube pumps for c box and engine transmissions are punted on same accessory drive and are visible on exterior of c box

Caliber assembly for rotor brake is on rear cover of c box, with calipers working against disc mounted on splined adapter to aft output shaft

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Engine and Combining Transmission Primary Lubrication

A

3 compartment tank on top of c box supplies oil to engine transmissions and c box. Tank is approx 10 gallons

Within c box main oil pumps for each transmission provide pressure to their respective engine, passing oil through an oil filter, 2 oil coolers, and in line jet protection screen before passing onto lube jets. Scavenge oil pump is provided for each transmission to return oil to reservoir

Chip detectors located in transmission sump with burn off system, to prevent minute metallic particles. These illuminate XMSN CHIP DET and ENG CHIP DET lights, and to determine which transmission has chips the maintenance panel in aft fuselage area must be consulted

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Engine/C Box Reservoir

A

1 big tank with 2 walls inside tank divide it into 3 separate chambers. Common filler and breather aperture is on top.

At the base of each compartment is combined temp bulb and overlay switch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Engine/C Box Pressure Pumps

A

3 pressure pump are housed within c box, and are driven from common shaft and each draws oil from its own section of reservoir

Extreme pressure is released by a relief valve for protection of system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Engine/C Box Filter

A

Filter mounted on rear side of c box, fitted to its respective pump outlet

Bypass indicator pops out to indicate blockage in element and oil will bypass filter to the system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Engine/C Box Oil Coolers

A

2 coolers attached to rear pylon and each is made of 3 separate sections. Each pump delivers oil to section of one then the other cooler

Bypass valve attached to each cooler inlet acts as thermal control valve and opens at temps below approx 70*C. Valve also acts as safety bypass should cooler becomes blocked

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Engine/C Box Jet Protection Screens

A

Screens stop contaminants from block feed jets when filters bypass

Sounds like a last chance oil filter

20
Q

Engine/C Box Pressure Switch

A

Causes XMSN OIL PRESS to come on if system falls below 18psig

115VAC and CB is on No. 2 PDP

21
Q

Engine/C Box Pressure Transducer

A

Fitted to pressure line of each oil system, converts pressure into electrical signals, power supply is 115VAC and CB is on No. 2 PDP

22
Q

Engine/C Box Chip Detector

A

Fitted to base of c box and engine nose boxes, illuminate XMSN CHIP DET or ENG CHIP DET light and trips mx panel magnetic indicator

23
Q

Engine/C Box Temp Bulb

A

Temp transducers located in associated portion of 3 section oil tank

24
Q

Engine/C Box Thermal Temp Switch

A

Located in primary pressure line just before the inlet of oil cooler
Close when temps reach above 140*C, this completes a ground circuit and illuminates XMSN OIL HOT

Engine transmissions have thermal switches fitted to base of each engine transmission case. They cause ENG 1/2 XMSN HOT light to come on if temp exceeds 207*C

25
Q

Engine/C Box Debris Screen

A

Located in each ENGINE transmission SCAVENGE return line

Bolted to inlet return of respective scavenge pump, when metal particles get trapped by screens they activate SCREEN ENG XMSN LEFT/RIGHT magnetic indicator on mx panel and simultaneously light ENG 1/2 CHIP DET light

26
Q

Engine/C Box Scavenge Pump

A

One scavenge pump for each gearbox lube system, driven by same shaft as pressure pumps, and return oil back to respective section of 3 compartment reservoir

27
Q

Engine/C Box Aux Lubrication

A

Independent from main lube system provided for each engine and c box transmission, is running anytime the primary system is functioning. It has its own pump, filter, pump relief valve, low pressure switch, and lube jets

Both primary and aux lube systems designed to pump return oil into aux sump. The sumps are located within each of 3 main sumps in reservoir. Oil fills aux sump first and then overflows into main sump

Aux lube system provides essential lubrication fro critical bearings and gears for up to TWO HOURS

Aux oil does NOT flow through the oil coolers and there is no provision for cooling oil

28
Q

Eng/C Box Aux Pump

A

3 separate pumps, mounted on forward side of c box, driven by common shaft in c box

Each pump draws oil from respective aux sump

29
Q

Eng/C Box Aux Oil Pressure Switch

A

Operates when system pressure falls below 10 psi, causes shared XMSN AUX PRESS light to come on and respective aux lube pressure magnetic indicator on mx panel

Mx panel must be consulted to determine which aux system is at fault

30
Q

Forward Transmission

A

Gearbox built with forward rotor shaft INCLINED at 9 degree angle, internally has spiral bevel pinion gear, ring gear, and 2 stages of planetary gears

Accessory drive gears in transmission drive main and aux oil pump and main rotor tach. Main oil pump is fitted to forward underside of gearbox and is accessible externally. It draws oil from sump, pressurizes it, and passes oil to oil cooler in aft pylon area and onto main bear surfaces and gears of forward transmission

Aux pump is within forward transmission housing, forward of rotor head shaft.

Main rotor tach is attached to outer face of main oil pump, consists of small 3 phase AC generator, frequency of AC current is measured and represented as rotor speed percent

Chip detector in aux sump of gearbox illuminate XMSN CHIP DET and must be identified by transmission mx panel

31
Q

Forward Transmission Main Lube System

A

Comprised of:

  1. Wet type sump
  2. Main pump protective screen
  3. Pressure pump
  4. Pump relief valve
  5. Filter
  6. Oil cooler

Oil from sump goes through screen and into inlet of pump, pump pushes oil through filter, oil cooler, and jet protection screen to transmission inlet

Oil then goes to lubricators and jets within transmission, spraying oil on transmission bearing and rotating gears

32
Q

Forward Transmission Main Sump

A

Wet sump at base of gearbox, integral funnel shaped casting in center of base forms aux system sump to which all oil is returned

Oil is directed to aux sump, which fills first, then overflows to main sump area

16 us quarts

33
Q

Forward Transmission Main Pressure Pump

A

Mounted on forward bottom side of transmission casing, pump is driven by accessory drive shaft also driving rotor tach

34
Q

Forward Transmission Cooler

A

Lowest radiator cooler on aft pylon is for forward transmission

When oil temp is above approx 70*C a bypass valve closes and directs oil through the cooler

Bypass valve also acts as a safety relief should cooler becomes blocked

35
Q

Forward Transmission Pressure Transducer

A

Fitted to RH side of each rotor gearbox, converts oil pressure to electric signals to power instrumentation in cockpit

Power supply is 115VAC and CB is on No. 2 PDP

36
Q

Forward Transmission Pressure Switch

A

Fitted downstream of each pressure transducer, causes XMSN OIL PRESS light to come on at 18psi with diminishing pressure

CB is on No. 2 PDP

37
Q

Forward Transmission Chip Detector

A

Fitted to aux sump of forward transmission, illuminates XMSN CHIP DET and simultaneously triggers magnetic indicator on transmission mx panel in ramp area

Power supply is 28vdc from emergency bus system and CB is No. 1 PDP

38
Q

Forward Transmission Aux Lube System

A

Aux lube system provides lube to limited section of gearbox and is complete and separate system from main lube system

Contained entirely within the forward transmission housing

Consist of:

  1. Aux sump
  2. Sump screen
  3. Aux pump
  4. Filter
  5. Low oil pressure switch

Oil is totally self contained and not allowed to flow to the oil cooler

39
Q

Forward Transmission Aux Oil Pump

A

Pump is driven by internal gear trains and independent of main oil drive

Pump draws oil from aux sump and pressurizes it to 1.25gpm at 80psig

Pressure relief valve opens at 90psig

40
Q

Forward Transmission Aux Oil Filter

A

Located externally on left side of lower transmission housing, filters oil from aux pump to lube jets

41
Q

Forward Transmission Aux Low Oil Pressure Switch

A

Located beside aux oil filter on left lower side of transmission housing

Illuminates XMSN AUX PRESS if pressure falls below 10psi, will also simultaneously operate magnetic indicator on mx panel

42
Q

Aft Transmission

A

Transmits torque from aft synch shaft to aft vert drive shaft, rotor shaft is tilted forward 4*, consists of spiral bevel gear, ring gear, and 2 stage of planetary gears for reduction

Contains 2 accessory drive gears:

  1. First one driven by input shaft and drives oil cooler blower shaft and oil scavenge pump. Blower shaft provides drive for oil cooler fan and via an accessory pad, the backup flight control hydraulic pump and emergency generator
  2. Second accessory gear drives AGB section with a sprag clutch. AGB drives lube pump, 2 flight control hydraulic pumps, 2 AC generators, utility hydraulic pump, 2 generator scavenge pumps, and AGB motor

Transmission has main and aux system:

  1. Main system is is pressure system with wet sump, temp bulb, chip detector, pump protection screen, drain valve, pressure switch. Main system also lubes thrust gear on aft vert shaft. Thrust bearing return oil return line contains chip detector and oil filter
  2. Aux system consists of integral pump, pump protection screen, filter, and pressure switch.
43
Q

Aft Transmission Main Lubrication

A

Consists of:

  1. Wet type sump
  2. Pump protection screen
  3. Pressure pump
  4. Relief valve
  5. Filter
  6. Oil cooler

Oil is drawn from sump through protection screen and into inlet of pump. Pump pressurizes system and oil goes through filter, cooler, and strainer to transmission inlet port. Oil supplied through external piping goes to aft vert shaft thrust bearing. Passages in transmission deliver oil to lubricators and jets, which spray oil onto gears and bearings

Pressurized oil also lubricates accessory drives at rear of transmission. External pressure line provides oil to the oil cooled generators, and scavenge pump returns oil to sump.

Flexible tube at bottom of accessory drive case allows oil from accessory gears and bearing to drain into sump

Scavenge pump in fan drive housing is driven by fan drive shaft, pump returns oil, which collects in forward part of transmission during nose low attitudes, to main sump

Mains sump holds 22.5 us quarts. Components on sump include:

  1. Oil temp bulb on forward sump wall
  2. Chip detector on bottom of aux sump
  3. Magnetic plug
  4. Drain valve at aft end of sump
44
Q

Aft Transmission Drive Shaft Lubrication

A

Aft drive shaft secured to aft transmission deck by cast housing and thrust bearing. Thrust bearing is lubricated with oil from main lube line

Return oil passes filter and chip detector, which activates SHAFT magnetic indicator on mx panel and XMSN CHIP DET on master caution panel

If aft transmission lube system fails, thrust bearing would NOT be lubricated

45
Q

Aft Transmission Aux Lube System

A

Identical to forward transmission aux lube system

46
Q

Transmission/Engine Chip Detector Burn-Off System

A

Installed to prevent minute metallic particles from activating warning system

Operates automatically and consists of zapper module (located at right side of aircraft) and 8 chip detectors

Module contains capacitors, circuitry, and electro mechanical four digit counter for each chip detector

When particles build up and bridge magnetic contacts of chip detector, capacitor is discharged to burn off particles and counter is advanced one digit

Larger particles cannot be burned off and will activate chip detector and indicators. Switch is provided to disable the system. When disabled, warning light located on zapper module will come on indicating system is inop and annoying chip detector indications could result

BV234 (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions