汽车底盘构造 汽车自动变速器 2009－(2).ppt

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1、1 第三节第三节 行星齿轮变速机构行星齿轮变速机构 行星行星齿轮变速器的速器的结构构组成成 行星行星齿轮变速器的工作原理速器的工作原理行星行星齿轮机构在自机构在自动变速器上的速器上的应用用2一、行星齿轮机构一、行星齿轮机构行星行星齿轮齿轮中心中心齿轮齿轮行星行星架架齿圈齿圈组装组装图图34行星齿轮机构的组成行星齿轮机构的组成5二、行星齿轮变速原理二、行星齿轮变速原理行星行星轮力平衡条件：力平衡条件：F1=F2F3=-2F1三元件上的力矩分三元件上的力矩分别为：太阳太阳轮M1=F1r1=z2/z1=r2/r1,r3=(r1+r2)/2 齿圈圈M2=F2r2=F1r1 行星架行星架 M3=F3r3

2、=-(+1)F1r1能量守恒三元件能量守恒三元件输入和入和输出功率出功率的代数和等于零的代数和等于零M11+M2+M3=0n1+n2-(1+)n3=0r61.行星齿轮机构变速比计算行星齿轮机构变速比计算传动比比i=从从动件件齿 数数/主主动件件齿数数n1+n2-(1+)n3=072.变速原理（加速）变速原理（加速）当太阳当太阳轮固定，行星架固定，行星架输入，入，齿圈圈输出出时传动比比为：n1+n2-(1+)n3=0 n1=0i=n3/n2=/(1+1/)1为超速超速传动行星架和行星架和齿圈圈转向相同。向相同。83.变速原理（加速）变速原理（加速）当当齿圈固定，圈固定，行星架行星架输入，入，太阳

3、太阳轮输出出时为超速超速传动，传动比比为：i=n3/n1=/(1+)1行星架和太阳行星架和太阳轮转向相同。向相同。94.变速原理（减速）变速原理（减速）当当齿圈固定，圈固定，太阳太阳轮输入，入，行星架行星架输出出时为减速减速传动，传动比比为：i=n1/n3=1+行星架和太阳行星架和太阳轮转向相同。向相同。105.变速原理（减速）变速原理（减速）当太阳当太阳轮固固定定齿圈圈输入，入，行星架行星架输出出时为减速减速传动，传动比比为：i=n2/n3=1+1/齿圈和行星架圈和行星架转向向相同相同。116.变速原理（倒挡）变速原理（倒挡）当行星架固定，当行星架固定，太阳太阳轮输入，入，齿圈圈输出出时，为

4、减速减速传动，传动比比为：n1+n2-(1+)n3=0n3=0n1/n2=-太阳太阳轮和和齿圈圈转向相反。向相反。127.转速及旋转方向转速及旋转方向固定件固定件主动件主动件 从动件从动件 转速转速旋转方向旋转方向齿圈齿圈太阳轮太阳轮 行星架行星架 减速减速与主动件同向与主动件同向行星架行星架 太阳轮太阳轮 加速加速太阳轮太阳轮齿圈齿圈行星架行星架 减速减速与主动件同向与主动件同向行星架行星架齿圈齿圈加速加速行星架行星架太阳轮太阳轮齿圈齿圈减速减速与主动件反向与主动件反向齿圈齿圈太阳轮太阳轮 加速加速13Planetenbersetzung Formeltabelle14 三、行星齿轮机构在自

5、动变速器上的应用三、行星齿轮机构在自动变速器上的应用有三个行星排，可有三个行星排，可组合出四个档位合出四个档位不同行星排有的元件是公用的不同行星排有的元件是公用的固定元件的固定元件的动作由制作由制动器和器和单向离合器完成向离合器完成1515Automatic Transmission Gearsets1616Simple Gear SetA planetary gear set has three major components:A sun gear in the center,A planet carrier with two or more pinion gears,and A ring

6、/internal gear.These are also called members.Ring/Internal GearSun GearCarrier with Planet Pinion Gears1717Connections,InputAt least one,or two,of these members will be connected to the torque converter through a multidisc clutch.It can be the input when the clutch is applied.This ring/internal gear

7、 can be driven by the forward clutchFront Ring/Internal GearForward ClutchAnimation:Clutch Operation1818Connections,OutputAt least one of the members will be connected to the transmission output shaft so it can transfer torque to the final drive.Splines are used to connect this front carrier to the

8、output shaft.Note that a complete planetary gearset is shown with all three members.Output ShaftFront CarrierSplines1919Connections,ReactionWhen a gear ratio change is desired,one of the members must be held stationary in reaction.This carrier can be held by a roller clutch or multidisc clutch.A ban

9、d is also used to hold the reaction member.Rear Carrier with Lo&Rev.Clutch HubRear Clutch HousingRoller ClutchAnimation:One-Way Roller Clutch2020Carrier with PinionsThis carrier has four pinion gears.The carrier is constructed so that it can be held in reaction by a multidisc clutch.It is also conne

10、cted to another gearset member.Hub for Lo and Reverse ClutchPlanet Pinion Gear2121Planet Pinions The pinion gears are mounted in the carrier so they can rotate freely on their shaft.Parts of a carrier are shown.Pinion GearNeedle BearingsPinion Pin/ShaftThrust WasherThrust Washer2222Simpson Gear SetT

11、his gear set combines portions of two simple gear sets as shown.The front ring gear and sun gears are inputs.Some internal parts are not shown2323Ravigneaux GearsetMost transmissions use a more complex gearset.Some use a Ravigneaux design that has two sun gears of different sizes and a carrier with

12、two set of planet pinions,a long and a short set.This gearset can produce four forward speeds plus a reverse.Ring GearLong Pinion GearShort Pinion GearLarge/Front Sun Gear Small/Rear Sun GearCarrier2424Ravigneaux Gearset,ExplodedReverse Sun GearForward Sun GearRing GearShort PinionLong PinionThis AO

13、D-E gear set has four forward speeds plus reverse and neutral.Carrier2525Simpson GearsetThis gearset is used in many 3-speed transmissions.It uses two planetary sets with a common sun gear.Sun GearRear Ring/Annulus GearRear CarrierFront Ring/Annulus GearFront Carrier2626Four Speed GearsetThis modern

14、 4-speed transmission uses a complex gearset.Two planetary sets are used with the ring/annulus gear of each set combined with the carrier of the second set.Front Sun GearRear Sun GearRear Carrier&Front Annulus/Ring Gear/Output ShaftFront Carrier&Rear Annulus/Ring Gear2727Shift ControlAutomatic trans

15、missions use different driving devices,usually multiplate clutches,to send the power flow to the proper gearset member and different reaction devices to hold the proper member in reaction.These members are applied or released to get the proper gear ratio.2828Shift ControlAutomatic trans-missions use

16、 differ-ent driving devices,usually multiplate clutches,to send the power flow to the proper gearset member and differ-ent reaction devices to hold the proper member in reaction.2929Planetary OperationThis chart shows how a simple planetary gearset can produce six different gear ratios depending on which member is driven or held.In addition to the three reduction or overdrive(OD)or forward or reverse ratios,a direct drive,1:1,ratio occurs if two members are driven.Neutral results if no members are driven.#1:#2:#3:#4:#5:#6: