工科 课程设计 变速器

1、.Chapter 1 Overview of CFM56-5C1.1 PreviewIn this chapter, a general introduction to CFM56-5C engine will be given. Some basic information about CFM56-5C engine will be included. Before learning it, try to recognize the abbreviations. They will help you getting a better understanding of the text in

2、the whole introduction.1.2 CFM InternationalIn 1974, GE of the U.S. and SNECMA (SAFRAN Group) of France founded the CFM International (CFMI), a 5050 joint company that would be responsible for producing and marketing the 10-ton engine, the CFM56.The two primary roles for CFMI were to manage the prog

3、ram between GE and SNECMA, and to market, sell and service the engine at a single point of contact for the customer.The work split between the two companies gave GE responsibility for the high-pressure compressor (HPC), the combustor, and the high-pressure turbine (HPT); while SNECMA was responsible

4、 for the fan, the low-pressure compressor (LPC), and the low-pressure turbine (LPT). SNECMA was also responsible for the initial airframe integration engineering, mostly involving the nacelle design, and was initially responsible for the gearbox, but shifted that work to GE when it became apparent t

5、hat it would be more efficient for GE to assemble that component along with their other parts.1.3 The CFM56-5C Turbofan Engine1.3.1 GeneralThe CFM56-5C series engine is an axial flow, dual spool, high bypass ratio, turbo-fan engine with fan and multistage compression systems driven by reaction turbi

6、nes. The engine is designed for use with a long duct, forced mixed flow exhaust system. The single stage fan and 4 stage booster is driven by a 5 stage low pressure turbine. A 9 stage, variable geometry, high pressure compressor is driven by an air cooled single stage turbine. A full annular combust

7、or with 20 duplex fuel nozzles distributes the fuel to provide the heat energy to drive the turbines with residual energy providing thrust. The accessory drive system extracts energy from the high pressure rotor to drive the engine and engine-mounted aircraft accessories. Reverse thrust for braking

8、the aircraft after landing is supplied by an integrated system which acts on the fan discharge airflow.The principal operational differences between the CFM56-5C series engine models are summarized below: Table 1-1 Differences between the CFM56-5C series engine modelsENGINE MODELTAKEOFF THRUST RATIN

9、GMAX. EGT deg.CCFM56-5C2 31,200 lbs (13,878 daN) 950 CFM56-5C2/F 31,200 lbs (13,878 daN) 965 CFM56-5C2/G 31,200 lbs (13,878 daN) 975 CFM56-5C3/F 32,500 lbs (14,456 daN) 965 CFM56-5C3/G 32,500 lbs (14,456 daN) 975 CFM56-5C4 34,000 lbs (15,123 daN) 975 Fig.1-1 CFM56-5C Fig.1-2 View of the CFM56-5C fro

10、nt fan and fan case1.3.2 Main modulesThe main modules of the engine are: - the fan and booster - the high pressure compressor- the combustor chamber- the high pressure turbine- the low pressure turbine- the accessory drive gearbox. Fig.1-3 main modules of CFM56-5CFan and Booster1.Fan/Booster rotor T

11、he fan rotor consists of one full diameter single stage fan and a smaller 4 stage booster for the core engine flow.The fan and the booster are mounted on a common internal concentric shaft driven by the 5 stage fan turbine. Two bearings support the fan assembly in the fan frame.2. Fan /Booster stato

12、rFixed stator vanes are provided for both the fan and the rotors. The fan casing, in which the fan stator is mounted, has provisions for blade containment forward of and in the plan of the fan rotor. The casing is supported by the fan frame and also supports the accessory drive gearbox.3. Fan frameT

13、he fan frame is one of the major structural and aerodynamic components of the engine. Aerodynamically the fan frame forms the inner and outer flow passage of the fan and core airstreams.Structurally the fan frame functions are:- to carry inlet cowl loads- to support the fan casing, the two fan beari

14、ngs and the core engine forward bearings- to contain the forward engine mount- to house the accessory drive power take off gearbox and radial drive shaft- to contain the variable bypass valve between the booster and high pressure compressor- to support the transfer and accessory gearboxes- to provid

15、e mounting surfaces for the fan-stream acoustic panelsThis frame also serves as the forward support for the high compressor.Compressor1. Compressor rotorThe compressor is a 9 stage axial flow assembly. The rotor consists of the stage 1 and 2 disks which form a spool, a separately attached stage 3 di

16、sks and a spool containing stage4-9 disks. Stages 1, 2 and 3 disks have axial dovetail slots and stages 4-9 blades are retained in circumferential slots. All blades are individually replaceable without spool disassembly.2. Compressor statorAll 9 stages of the compressor stator are shrouded. The Inle

17、t Guide Vanes (IGV) and the first 3 stages of the compressor are variable. The casing is composed of two semi-cylindrical halves, permitting a quick access to the core engine compressor.CombustorA step diffuser is incorporated upstream of the combustor for reduction of the combustor sensitivity to t

18、he compressor velocity profile. The combustor can be replaced without disturbing the fuel nozzles. The combustor casing provides structural support for the combustor, the compressor Outlet Guide Vanes (OGV), the High Pressure (HP) stator and shrouds, and the seals for the Compressor Discharge Pressu

19、re (CDP).Turbine1. High pressure turbineThe High Pressure Turbine (HPT) is an air-cooled single-stage high-energy turbine. Rotor blades are individually replaceable without the need for rotor disassembly or re-balancing.2. Low pressure turbineThe Low Pressure Turbine (LPT) consists of 5 stages of bl

20、ades and vanes. The first stage nozzle vane is cooled and transfers cooling air for the high pressure and low pressure turbine disks. The LPT drives the fan rotor through the inner concentric shaft and is aerodynamically coupled to the high pressure system. The LPT casing is a 360 degree design to p

21、rovide structural continuity. The front flange of the LPT casing supports the A8 flange extension and the partial axial flow bulkhead.Fig.1-4 Low pressure turbineTurbine frameThe turbine frame is located aft of the LPT. It contains the aft LPT bearing, and supports the mixer and center body. This fr

22、ame contains the engine rear mount fitting.Accessories and accessory drivesThe engine and aircraft accessories are mounted on the accessory gearbox which is located on the lower portion of the fan casing and is driven by a shaft from the transfer gearbox. Power for the engine and the aircraft access

23、ories is extracted from the HPC rotor shaft to the transfer gearbox. Quick Attach Detach (QAD) accessory mounting flanges are provided for all accessories.1.3.3 The advantages of CFM56-5CQuick facts:· Lowest SFC of the CFM56 family · Quietest engine in its thrust class · High thrust-t

24、o-weight ratio to provide excellent takeoff performance for high-altitude and hot airfields · 36,000 pounds of thrust demonstrated during ground testing · Second-generation FADEC Long-duct, mixed-flow nacelle developed by CFM to provide significant noise attenuation, reduced fuel burn, and

25、 increased climb thrust Chapter 2 LPT Shaft of CFM56-5C2.1 PreviewAs we all know, the N1 Speed is the LP rotor assembly rotational speed. So in this chapter, we will introduce the LPT Shaft of CFM56-5C. And in the next chapter, we will introduce the fan and booster, for The Low Pressure Turbine (LPT

26、) shaft module connects the fan shaft with the LPT rotor.2.2 System DescriptionThe LPT shaft module is composed of the LPT shaft and of the center vent tube.The aft end of the LPT shaft is supported by the NO.5 bearing, its forward end is coupled with the fan shaft. The LPT shaft has 2 functions: co

27、upling the fan/booster rotor with the LPT rotor and providing for high pressure turbine rear support through the NO.4 bearing. In addition, the LPT shaft houses the center vent tube for venting forward and aft engine sumps.Fig.2-1 Low Pressure Turbine Shaft ModuleFig.2-2 Low Pressure Turbine Shaft A

28、ssembly2.3 Component DescriptionThe LPT shaft module consists of the following major parts:- LPT shaft- Center Vent Tube (CVT)- NO.4 roller bearing- NO.5 roller bearing2.3.1 LPT Shaft The LPT shaft is made of steel alloy. It is located concentrically in the high pressure rotor system. Its forward en

29、d is provided with outer splines for coupling with the fan shaft. It is axially retained by a shoulder and a coupling nut. At the aft end of the shaft, the NO.4 and 5 bearings are located axially on both sides of an integral hub. On the rear face, the hub supports 2 rotating air/oil seals which cont

30、rol the air circulation through the LPT rotor and the sump pressurizing air. On the front face, the hub supports the turbine rotor support.2.3.2 Center Vent TubeThe one-piece center vent tube (CVT) is made of titanium alloy. It is installed inside the LPT shaft. It forward end is inserted in the LPT

31、 shaft plug and its aft end is supported by the LPT shaft hub. The center vent tube is held radially in the LPT shaft through 2 expendable-type supports. At the front of the NO.5 roller bearing, 3 shoulder-pins engage the shaft hub and the center vent tube to prevent it to turn relative to the LP sh

32、aft. The 3 pins also supply for the correct location of the NO.5 bearing inner race. 2.3.3 NO.4 Bearing The NO.4 bearing, which takes the High Pressure Turbine (HPT) rotor radial loads, is a roller bearing installed between the HPT rear shaft and the LPT shaft. The bearing outer race is housed in th

33、e HPT rear shaft bore, and its inner race is bolted to the front face of the LPT shaft integral hub. The inner race has a shoulder which would act as an emergency bearing in case of roller failure. The inner race front end is provided with a sump air seal.2.3.4 NO.5 BearingThe NO.5 bearing supports

34、the LPT rotor aft end inside the turbine frame and takes the radial loads. The bearing outer race is mounted in the turbine frame and its inner race is mounted at the rear of the LPT shaft integral hub. Chapter 3 Fan and Booster Assembly3.1 PreviewIn the last chapter, we have known The Low Pressure

35、Turbine (LPT) shaft module connects the fan shaft with the LPT rotor. In order to known N1 Speed well, in this chapter, we are going to introduce the fan and booster assembly.3.2 General The fan and booster assembly consists of a single-stage fan rotor and a 4-stage axial booster, cantilever-mounted

36、 at the rear of the fan disk.3.3 Component DescriptionThe fan and booster assembly consists of the following sections:- spinner rear and front cones- fan disk- fan blades- booster rotor - booster vane assemblies 3.3.1 Spinner Front Cone The spinner front cone is made of composite material. Its desig

37、n precludes the need for an engine nose anti-icing system. The front cone is bolted to the rear cone. 3.3.2 Spinner Rear ConeThe spinner rear cone is made of aluminum alloy. Its rear flange is bolted to the fan disk and is part of the fan blades axial retention system. The outer rim of rear flange i

38、s provided with tapped holes for trim balance screws. The front flange provides for attachment of the spinner front cone.3.3.3 Fan Disk The fan disk is a titanium alloy forging. Its inner rear flange provides attachment for the fan shaft and its outer rear flange is bolted to the booster rotor. The

39、outer front flange provides attachment for the spinner rear cone. The disk outer rim has 36 recesses designed for fan blade retention. 3.3.4 Fan BladesThere are 36 titanium alloy, mid-span shrouded, fan blades approximately 25 inches (630 mm) long. Each blade has a dovetail base that engages in a do

40、vetail recess on the disk rim. A spacer limits the radial movement of each blade. A retainer lug, machined in the rear end of blade root, engages the forward flange of the booster spool and limits the forward and rearward axial movements. 3.3.5 Booster Rotor The booster rotor consists of the booster

41、 spool and blades. The booster spool is forged and machined from titanium alloy and is cantilever-mounted on the rear of the fan disk. The inner front flange, bolted to the fan disk, acts as a stop for the fan blade spacers and the fan blades. The 4-stage spool has circumferential dovetail slots tha

42、t retain the stages 2, 3, 4, and 5 booster rotor blades, locking lugs and balance weights. Stage 2 has 70 blades, stage 3 has 74 blades, stage 4 has 70 blades and stage 5 has 66 blades. Rotating air seal serrations are machined between each stage on the outer diameter of spool.A forward rotating air

43、 seal, integral with the front web of booster spool, provides partial sealing between the fan rotor stage and the inner shroud of booster stator stage 2 and (partial) pressurization of the engine forward sump. The booster blades are approximately 4.2 to 3.5 inches (105 to 90 mm) long and serve prima

44、rily to supercharge the HP compressor. Blades are held in the dovetail slots by locking lugs.3.3.6 Booster Stator The stacked vane assemblies of booster stator are cantilever-mounted on the fan frame front face. The entire assembly is composed of 5 vane stages of similar design. Each vane assembly c

45、onsists of:- An outer shroud which, depending on its assembly location, is fitted with one or 2 mounting flanges at its ends. The outer shroud inner face of vanes assemblies, stages 1, 3, 4 and 5 is lined with an abradable material facing, respectively, the 1, 2, 3 and 4 rotor blades- An inner shrou

46、d, whose inner face is lined with abradable material facing the seal serrations machined on the booster spool - Stator vanes welded to the outer shroud and retained on the inner shroud by the abradable material. Stage one vane assembly has 106 vanes, stage 2 vane assembly has 124 vanes, stage 3 vane

47、 assembly has 124 vanes, stage 4 vane assembly has 116 vanes and stage 5 vane assembly has 90 vanes. The outer shroud rear flange of stage 5 vane assembly is bolted to the front face of the fan frame. The inner shroud rear flange is rabbeted to form an interference fit with a corresponding flange on

48、 the fan frame. The outer shroud of the booster stage 3 and stage 5 vane assemblies has an orifice, located approximately at 4.30 o'clock, to permit the borescope inspection of the booster mid and rear stages rotor blades (full view) and of the related vane assemblies (partial view only).Fig.3-1

49、 Fan and Booster AssemblyFig.3-2 Fan and Booster Assembly-Section ViewChapter 4 Power and Speed Indicating4.1 PreviewIn order to solve the problem of N1 over-limit, we must know how do the Speed Indicating System work and how do the N1 Speed signal transfer. So in this chapter, we are going to intro

50、duce the Power and Speed Indicating of CFM56-5C engine. 4.2 Describe and Operation4.2.1 GeneralThe N1 speed sensor and the N2 speed sensor detect respectively: - the LP rotor assembly rotational speed- the HP rotor assembly rotational speedThey transmit the signal to the following:- Engine Interface

51、 Vibration Monitoring Unit (EIVMU) (for N1 speed sensor only)- Electronic Control Unit (ECU): channel A and channel B.4.2.2 Component LocationThe N1 speed sensor is installed inside the fan frame in strut 4, at the 4 o'clock position (ALF). The N2 speed sensor is installed at the rear face of th

52、e accessory gearbox to the left of the horizontal drive shaft housing.4.2.3 InterfaceThe N1 and N2 indications from the sensors are received by the ECU, digitized by the ECU and then transmitted via the ECU ARINC outputs to the Display Management Computer (DMC) for display on EWD, to the Flight Warn

53、ing Computer (FWC) for warning activation and to the Engine Interface Vibration Monitoring Unit (EIVMU) for the vibration analysis process.Fig4-1.Interface and Indicating4.2.4 Component DescriptionN1 Speed Sensor1. DescriptionThe N1 speed sensor consists of the following: - one magnetic head (sensor

54、 probe) which includes 3 windings, 3 permanent magnets and the pole pieces - three pairs of shielded lead wires providing the electrical signals from the sensing elements to the connectors- one rigid metal tube including two bonded damping rings- one flange for attachment of the sensor to the engine

55、- one three-connector receptacleWhen the N1 speed sensor is installed on the engine, only the components below can be seen: - the three-connector receptacle- the connector head- the sensor securing flange2. OperationThis sensor is an induction type tachometer. It consists of 3 independent sensing el

56、ements which are magnetically and electrically insulated from one another. Each sensing element includes a magnet as a pole piece and a winding. The sensing elements transmit signals. The signals are supplied to the connectors through conductors embedded in a metal tube. A sensor ring installed on t

57、he fan shaft is provided with 30 teeth. The passage of each tooth changes the magnetic field of the magnets and causes a flux variation in the coils. This generates an alternating electromotive force proportional to the rotational speed of the low pressure assembly. NOTE: The sensor ring has one too

58、th thicker than the 29 others. This tooth generates a signal of greater amplitude used as phase reference for trim balance purpose by the EIVMU.N2 Speed Sensor 1. DescriptionThe N2 speed sensor consists of the following:A body including: - three fixed connectors - one flange for attachment to the AGB - one groove which accommodates a seal for tightness between sensor and AGBA metal rigid tube including a magneti