DOC AIRBUS | AMM A320FPNEUMATIC STARTER AND VALVE SYSTEM - DESCRIPTION AND OPERATION
** ON A/C NOT FOR ALL
** ON A/C NOT FOR ALL
1. Starter
The starter converts the compressed air flow coming from an engine, the APU or an external air source into a high torque rotary movement. This movement is transmitted to the engine HP rotor through the engine accessory drive system. The physical and operational characteristics of the starter are listed in Table 001.
The four inch diameter engine starter shutoff valve (SOV) is normally closed, electrically controlled and pneumatically operated.
** ON A/C NOT FOR ALL The starter converts the compressed air flow coming from an engine, the APU or an external air source into a high torque rotary movement. This movement is transmitted to the engine HP rotor through the engine accessory drive system. The physical and operational characteristics of the starter are listed in Table 001.
The four inch diameter engine starter shutoff valve (SOV) is normally closed, electrically controlled and pneumatically operated.
2. Component Location
Starter and Shutoff Valve Location ** ON A/C NOT FOR ALL
Starter and Shutoff Valve Location ** ON A/C NOT FOR ALL
The starter is installed at the rear of the accessory gearbox on the right side.
The starter shutoff valve is installed on the fan case at 3:00 o'clock position.
** ON A/C NOT FOR ALL Starter and Shutoff Valve Location ** ON A/C NOT FOR ALL Starter and Shutoff Valve Location ** ON A/C NOT FOR ALL The starter shutoff valve is installed on the fan case at 3:00 o'clock position.
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| FIN FUNCTIONAL DESIGNATION PANEL ZONE ACCESS ATA |
| DOOR REF. |
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| - STARTER 438 438AR 80-11-10 |
| 448 448AR |
| - VALVE-STARTER SHUTOFF 436 438AR 80-11-20 |
| 438BR |
| 446 448AR |
| 448BR |
3. Component Description
A. Description
(1) Starter
The starter consists primarily of an air inlet plenum and exhaust housing assembly (1) containing a turbine wheel stator (2) and radial containment ring (4), a high-speed pinion (9), a turbine wheel (3), a planetary gear set (25), three low speed pinions (24), an internal spur gear (ring gear) (23), a pawl and ratchet clutch assembly (13), a drive shaft assembly (17A), an output shaft (17), a carbon seal (16) and a gear housing assembly (10).
The gear housing assembly (10) provides for installation of magnetic drain plug assembly (22), oil overflow plug (19) and oil filler plug (31).
The magnetic drain plug (22) consists of an inner magnetic drain plug and an outer check valve plug. The outer check valve plug will prevent oil draining when magnetic plug is removed.
The starter consists primarily of an air inlet plenum and exhaust housing assembly (1) containing a turbine wheel stator (2) and radial containment ring (4), a high-speed pinion (9), a turbine wheel (3), a planetary gear set (25), three low speed pinions (24), an internal spur gear (ring gear) (23), a pawl and ratchet clutch assembly (13), a drive shaft assembly (17A), an output shaft (17), a carbon seal (16) and a gear housing assembly (10).
The gear housing assembly (10) provides for installation of magnetic drain plug assembly (22), oil overflow plug (19) and oil filler plug (31).
The magnetic drain plug (22) consists of an inner magnetic drain plug and an outer check valve plug. The outer check valve plug will prevent oil draining when magnetic plug is removed.
(2) Starter shutoff valve
The starter shutoff is composed of two major sections, the valve flow body section and the pneumatic actuator and control section.
The valve flow body section consists of the flow body, butterfly plate shaft, bearings and seals enclosed in the valve body.
The pneumatic actuator and control section consists of the controlling solenoid, diaphragms, torsion closing mechanism, shaft actuating linkage, electrical position indicating switch and pneumatic heating element.
The starter shutoff is composed of two major sections, the valve flow body section and the pneumatic actuator and control section.
The valve flow body section consists of the flow body, butterfly plate shaft, bearings and seals enclosed in the valve body.
The pneumatic actuator and control section consists of the controlling solenoid, diaphragms, torsion closing mechanism, shaft actuating linkage, electrical position indicating switch and pneumatic heating element.
(3) Starter
The starter consists primarily of an air inlet plenum and exhaust housing assembly (1) containing a turbine wheel stator (2) and radial containment ring (4), a high-speed pinion (9), a turbine wheel (3), a planetary gear set (25), three low speed pinions (24), an internal spur gear (ring gear) (23), a pawl and ratchet clutch assembly (13), a drive shaft assembly (17A), an output shaft (17), a carbon seal (16) and a gear housing assembly (10).
The gear housing assembly (10) provides for installation of magnetic drain plug assembly (22), oil overflow plug (19) and oil filler plug (31).
The magnetic drain plug (22) consists of an inner magnetic drain plug and an outer check valve plug. The outer check valve plug will prevent oil draining when magnetic plug is removed.
The starter consists primarily of an air inlet plenum and exhaust housing assembly (1) containing a turbine wheel stator (2) and radial containment ring (4), a high-speed pinion (9), a turbine wheel (3), a planetary gear set (25), three low speed pinions (24), an internal spur gear (ring gear) (23), a pawl and ratchet clutch assembly (13), a drive shaft assembly (17A), an output shaft (17), a carbon seal (16) and a gear housing assembly (10).
The gear housing assembly (10) provides for installation of magnetic drain plug assembly (22), oil overflow plug (19) and oil filler plug (31).
The magnetic drain plug (22) consists of an inner magnetic drain plug and an outer check valve plug. The outer check valve plug will prevent oil draining when magnetic plug is removed.
(4) Starter shutoff valve
The starter shutoff is composed of two major sections, the valve flow body section and the pneumatic actuator and control section.
The valve flow body section consists of the flow body, butterfly plate shaft, bearings and seals enclosed in the valve body.
The pneumatic actuators and control section consist of the controlling solenoid, diaphragms, torsion closing mechanism, shaft actuating linkage, electrical position indicating switch.
The starter shutoff is composed of two major sections, the valve flow body section and the pneumatic actuator and control section.
The valve flow body section consists of the flow body, butterfly plate shaft, bearings and seals enclosed in the valve body.
The pneumatic actuators and control section consist of the controlling solenoid, diaphragms, torsion closing mechanism, shaft actuating linkage, electrical position indicating switch.
B. Operation
(1) Starter
The inlet housing assembly (1) directs the flow of compressed air to the stator assembly (2) which, in turn, directs the air flow into the blades of turbine wheel (3), producing high speed and low torque rotation of turbine wheel (3).
Exhaust air is released to ambient at approximately ambient pressure. The pinion gear (9), the 3 matched planetary gear set (25), three low speed pinions (24) and internal ring gear transform the high speed rotation with low torque of turbine wheel (3) into low speed and high torque at output shaft (17).
The drive shaft assembly (17A) provides disengagement of output shaft (17) from internal ring gear (23) after air to starter is shutoff and when the aircraft engine speed exceeds pawl liftoff speed of drive shaft assembly (17A), allowing output shaft (17) and drive shaft assembly (17A) to rotate with the aircraft engine while pinion (9), internal ring gear (23), planetary gear set (25) and turbine wheel (3) coast to stop.
The inlet housing (1), incorporating axial containment ring (4) with axial cutter ring (30) cutter pins, provides turbine wheel (3) containment at speeds up to the maximum turbine free running speed. Should the turbine wheel (3) moves axially after a thrust bearing failure, the cutter pins (30) will cut the rim from the turbine wheel and the separated parts shall be contained in the axial and radial enclosed space of containment ring.
The sealing of the starter is ensured at output shaft assembly (17) by a carbon seal (16). A magnetic plug (22) in the gear housing (10) provides protection for the bearings by collecting any metallic particles in lubricant, and allows to detect starter failure by inspection.
The inlet housing assembly (1) directs the flow of compressed air to the stator assembly (2) which, in turn, directs the air flow into the blades of turbine wheel (3), producing high speed and low torque rotation of turbine wheel (3).
Exhaust air is released to ambient at approximately ambient pressure. The pinion gear (9), the 3 matched planetary gear set (25), three low speed pinions (24) and internal ring gear transform the high speed rotation with low torque of turbine wheel (3) into low speed and high torque at output shaft (17).
The drive shaft assembly (17A) provides disengagement of output shaft (17) from internal ring gear (23) after air to starter is shutoff and when the aircraft engine speed exceeds pawl liftoff speed of drive shaft assembly (17A), allowing output shaft (17) and drive shaft assembly (17A) to rotate with the aircraft engine while pinion (9), internal ring gear (23), planetary gear set (25) and turbine wheel (3) coast to stop.
The inlet housing (1), incorporating axial containment ring (4) with axial cutter ring (30) cutter pins, provides turbine wheel (3) containment at speeds up to the maximum turbine free running speed. Should the turbine wheel (3) moves axially after a thrust bearing failure, the cutter pins (30) will cut the rim from the turbine wheel and the separated parts shall be contained in the axial and radial enclosed space of containment ring.
The sealing of the starter is ensured at output shaft assembly (17) by a carbon seal (16). A magnetic plug (22) in the gear housing (10) provides protection for the bearings by collecting any metallic particles in lubricant, and allows to detect starter failure by inspection.
C. Starter Lubrication
The lubrication is a wet sump splash system. The approved lubricating oils are those specified by the generic term of "engine oil" (Material No.CP2442). For more information, refer to the CFMI Service Bulletin 79-001 which lists the approved lubricating oils in use on the engine and its accessories.
The lubrication is a wet sump splash system. The approved lubricating oils are those specified by the generic term of "engine oil" (Material No.CP2442). For more information, refer to the CFMI Service Bulletin 79-001 which lists the approved lubricating oils in use on the engine and its accessories.
(1) Table 001 - Physical and Operational Characteristics
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| Starter Physical and Operational Characteristics |
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| Turbine Type : Single stage axial flow |
| Reduction Gearing : Compound planetaty |
| Internal Engagement : Pawl and ratchet type |
| Drive Shaft Disengagement Speed : 4300 to 4500 RPM |
| Drive Shaft Reengagement Speed : 1720 to 2800 RPM |
| Direction of Output Shaft Rotation : CCW when viewing the starter output shaft |
| Lubrication. |
| System Type : Wet sump splash system |
| Capacity : 27.0 fl oz (800 cc approximately) |
| Lubricant Specification : Engine oil (Material No.CP2442 per CFMI SB 79-001) |
| Inlet Air Connection : 4.00 plus or minus 0.005 in. dia. (101.6 plus or |
| minus 0.12 mm) dia. |
| Weight (Dry) : 38 lb max (17.25 kg max) |
| Length (including output shaft) : 18.19 inches (462.5 mm) |
| Diameter, including filler and drain plugs : 9.29 inches (235.96 mm) |
| dia. |
4. Starter Shutoff Valve
A. Closing operation
The starter shutoff valve remains closed with the solenoid de-energized. Inlet air pressure is routed through a downstream facing probe and regulator orifice to chamber "A". This pressure is routed through the de-energized solenoid (position shown) and into chamber "B". Since the pressures on both sides of diaphragm "B" are equal, no net force remains. The pressure in chamber "A" exerts a force on diaphragm "A"; this force, in combination with the closing torsion spring force, closes the starter control valve.
The starter air valve remains closed with the solenoid de-energized. Inlet air pressure is routed through a downstream facing probe and an opening rate orifice in a chamber solenoid closed by non-return valve (position shown). The pressure in opening chambers is vented to ambient through the solenoid ball and the closing-rate orifice. The pressure in chambers at opposite position of the opening chambers is vented to ambient through the vent orifices. The internal springs of the pneumatic actuators in combination with the closing torsion spring force, closes the starter control valve.
The starter shutoff valve remains closed with the solenoid de-energized. Inlet air pressure is routed through a downstream facing probe and regulator orifice to chamber "A". This pressure is routed through the de-energized solenoid (position shown) and into chamber "B". Since the pressures on both sides of diaphragm "B" are equal, no net force remains. The pressure in chamber "A" exerts a force on diaphragm "A"; this force, in combination with the closing torsion spring force, closes the starter control valve.
The starter air valve remains closed with the solenoid de-energized. Inlet air pressure is routed through a downstream facing probe and an opening rate orifice in a chamber solenoid closed by non-return valve (position shown). The pressure in opening chambers is vented to ambient through the solenoid ball and the closing-rate orifice. The pressure in chambers at opposite position of the opening chambers is vented to ambient through the vent orifices. The internal springs of the pneumatic actuators in combination with the closing torsion spring force, closes the starter control valve.
B. Opening Operation
The starter shutoff valve is opened by energizing either of the solenoid coils. Energizing the solenoid actuates the solenoid ball to the position opposite that shown. The chamber "A" pressure is then blocked at the solenoid and the chamber "B" pressure is vented to ambient through the open rating orifice. With chamber "B" vented, the chamber "A" pressure is sensed on both diaphragms "A" and "B". Since diaphragm "B" is larger than diaphragm "A" the valve will actuate to the butterfly open position when the valve inlet pressure is sufficient to overcome the closing torsion spring.
The starter shutoff valve opening rate is controlled by the rate at which chamber "B" vents to ambient. These rates are controlled by the regulator orifice and the open rating orifice, respectively.
The starter air valve is opened by energizing either of the solenoid coils. Energizing the solenoid actuates the solenoid ball to the position opposite that shown and open the non-return valve. Inlet air pressure is routed in the opening chambers, then is sensed on both diaphragms and pistons of the pneumatic actuators. The pressure increase in the opening chambers and actuate the pistons when the pressure is sufficient to overcome the internal springs and the closing torsion spring. The pistons actuate to the butterfly open position.
The starter air valve opening rate is controlled by the rate at which chambers at opposite position of the opening chambers vents to ambient. These rates are controlled by the open rating orifice, the purging orifice and the closing rate orifice.
The starter shutoff valve is opened by energizing either of the solenoid coils. Energizing the solenoid actuates the solenoid ball to the position opposite that shown. The chamber "A" pressure is then blocked at the solenoid and the chamber "B" pressure is vented to ambient through the open rating orifice. With chamber "B" vented, the chamber "A" pressure is sensed on both diaphragms "A" and "B". Since diaphragm "B" is larger than diaphragm "A" the valve will actuate to the butterfly open position when the valve inlet pressure is sufficient to overcome the closing torsion spring.
The starter shutoff valve opening rate is controlled by the rate at which chamber "B" vents to ambient. These rates are controlled by the regulator orifice and the open rating orifice, respectively.
The starter air valve is opened by energizing either of the solenoid coils. Energizing the solenoid actuates the solenoid ball to the position opposite that shown and open the non-return valve. Inlet air pressure is routed in the opening chambers, then is sensed on both diaphragms and pistons of the pneumatic actuators. The pressure increase in the opening chambers and actuate the pistons when the pressure is sufficient to overcome the internal springs and the closing torsion spring. The pistons actuate to the butterfly open position.
The starter air valve opening rate is controlled by the rate at which chambers at opposite position of the opening chambers vents to ambient. These rates are controlled by the open rating orifice, the purging orifice and the closing rate orifice.
C. Manual Override Operation
The starter shutoff valve is manually opened by first pushing the wrench button and then rotating the lever. Pushing the wrench button vents chamber "A" and "B" past the manual override vent ball. Since the manual override vent is large compared the regulator orifice, the chamber "A" and "B" pressure decreases to ambient pressure and thus there is no diaphragm force in the actuator. The handle can be rotated against the closing torsion spring to open the butterfly. The manual override lever is constructed so that the wrench button is automatically retained in the pressed position as long as the lever is manually rotated to the valve-open position. When the handle is released, the torsion spring turns the shaft to the butterfly closed position and the button is automatically returned to the closed position by the action of the vent ball spring and the valve returns to normal operation.
The starter air valve is manually opened by rotating the lever because there is no diaphragm force and pressure in the pneumatic actuator. The handle can be rotated against the closing torsion spring to open the butterfly. When the handle is released, the torsion spring turns the shaft to the butterfly closed position the valve returns to normal operation.
The starter shutoff valve is manually opened by first pushing the wrench button and then rotating the lever. Pushing the wrench button vents chamber "A" and "B" past the manual override vent ball. Since the manual override vent is large compared the regulator orifice, the chamber "A" and "B" pressure decreases to ambient pressure and thus there is no diaphragm force in the actuator. The handle can be rotated against the closing torsion spring to open the butterfly. The manual override lever is constructed so that the wrench button is automatically retained in the pressed position as long as the lever is manually rotated to the valve-open position. When the handle is released, the torsion spring turns the shaft to the butterfly closed position and the button is automatically returned to the closed position by the action of the vent ball spring and the valve returns to normal operation.
The starter air valve is manually opened by rotating the lever because there is no diaphragm force and pressure in the pneumatic actuator. The handle can be rotated against the closing torsion spring to open the butterfly. When the handle is released, the torsion spring turns the shaft to the butterfly closed position the valve returns to normal operation.
D. Visual position indicator operation
The manual override lever aligns with markings on the valve body to provide an external indication of butterfly position.
The manual override lever aligns with markings on the valve body to provide an external indication of butterfly position.
E. Downstream facing probe
The valve contains a downstream facing probe which prevents contaminants from entering the valve actuator and also requires no maintenance.
The valve contains a downstream facing probe which prevents contaminants from entering the valve actuator and also requires no maintenance.
F. Pneumatic heating operation
The starter shutoff valve incorporates pneumatic solenoid heating to prevent icing of the solenoid valve. A small quantity of valve inlet air is routed through a flow control orifice, around the solenoid valve and then is vented to ambient.
The starter shutoff valve incorporates pneumatic solenoid heating to prevent icing of the solenoid valve. A small quantity of valve inlet air is routed through a flow control orifice, around the solenoid valve and then is vented to ambient.
G. Position switch operation
The normally open redundant electrical position switches are actuated by the closing end of the actuator to provide remote indication when the butterfly is in any position except closed.
The normally open redundant electrical position switches are actuated by the closing end of the actuator to provide remote indication when the butterfly is in any position except closed.
(1) Redundant solenoid
The solenoid has two independent coils including 3 wires wound together (1 active winding per channel and 1 shunt winding to both active channels), either one of which when energized will open the valve.
The solenoid has two independent coils including 3 wires wound together (1 active winding per channel and 1 shunt winding to both active channels), either one of which when energized will open the valve.
H. Overpressure protection
A relief valve is incorporated to limit the actuator pressure in the event that the inlet pressure exceeds the normal maximum value.
A relief valve is incorporated to limit the actuator pressure in the event that the inlet pressure exceeds the normal maximum value.