汽车底盘构造汽车自动变速器－课件

1、汽车底盘构造汽车自动变速器课件一、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行星齿轮机构的组成行星齿轮机构的组成二、行星齿轮变速原理二、行星齿轮变速原理 行星轮力平衡条件：行星轮力平衡条件：F1=F2F3=-2F1 三元件上的力矩分别为：三元件上的力矩分别为： 太阳轮太阳轮M1=F1r1=z2/z1=r2/r1, r3=(r1+r2)/2 齿圈齿圈M2=F2r2=F1r1 行星架行星架 M3=F3r3=-(+1)F1r1 能量守恒三元件输入和输出功率能量守恒三元件输入和输出功率的代数和等于零的代数和等于零M11+M2+M3=0 n1+n2-(1

2、+)n3=0r1.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传动比i=从动件齿从动件齿 数数/主动件齿数主动件齿数n1+n2-(1+)n3=02.变速原理（加速）变速原理（加速） 当太阳轮固定，行星架当太阳轮固定，行星架输入，齿圈输出时传输入，齿圈输出时传动比为：动比为：n1+n2-(1+)n3=0 n1=0i=n3/n2=/(1+1/)1为超速传动为超速传动 行星架和齿圈转向相同。行星架和齿圈转向相同。3.变速原理（加速）变速原理（加速）当齿圈固定，当齿圈固定，行星架输入，行星架输入，太阳轮输出时太阳轮输出时为超速传动，为超速传动，传动比为：传动比为：i=n3/n1=/(1+)1行星

3、架和太阳行星架和太阳轮转向相同。轮转向相同。4.变速原理（减速）变速原理（减速）当齿圈固定，当齿圈固定，太阳轮输入，太阳轮输入，行星架输出时行星架输出时为减速传动，为减速传动，传动比为：传动比为：i=n1/n3=1+行星架和太阳行星架和太阳轮转向相同。轮转向相同。5.变速原理（减速）变速原理（减速）当太阳轮固当太阳轮固定齿圈输入，定齿圈输入，行星架输出时行星架输出时为减速传动，为减速传动，传动比为：传动比为：i=n2/n3=1+1/齿圈和行星架齿圈和行星架转向相同。转向相同。6.变速原理（倒挡）变速原理（倒挡）当行星架固定，当行星架固定，太阳轮输入，太阳轮输入，齿圈输出时，齿圈输出时，为减速传

4、动，为减速传动，传动比为：传动比为：n1+n2-(1+)n3=0n3=0n1/n2=-太阳轮和齿圈太阳轮和齿圈转向相反。转向相反。7.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Planetenbersetzung Formeltabelle 三、行星齿轮机构

5、在自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，可组合出四个档位有三个行星排，可组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动作由制动器和单向离合器完成固定元件的动作由制动器和单向离合器完成15Automatic Transmission Gearsets16Simple 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

6、 ring/internal gear. These are also called members.Ring/Internal GearSun GearCarrier with Planet Pinion Gears17Connections, 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/ int

7、ernal gear can be driven by the forward clutchFront Ring/ Internal GearForward ClutchAnimation: Clutch Operation18Connections, 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 car

8、rier to the output shaft. Note that a complete planetary gearset is shown with all three members.Output ShaftFront CarrierSplines19Connections, 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 multidis

9、c clutch. A band is also used to hold the reaction member.Rear Carrier with Lo & Rev. Clutch HubRear Clutch HousingRoller ClutchAnimation: One-Way Roller Clutch20Carrier with PinionsThis carrier has four pinion gears. The carrier is constructed so that it can be held in reaction by a multidisc c

10、lutch. It is also connected to another gearset member.Hub for Lo and Reverse ClutchPlanet Pinion Gear21Planet 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 Washe

11、r22Simpson Gear SetThis 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 shown23Ravigneaux GearsetMost transmissions use a more complex gearset. Some use a Ravigneaux design that has two sun gears of different size

12、s and a carrier with 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 GearCarrier24Ravigneaux Gearset, ExplodedReverse Sun GearForward Sun GearRing GearShort Pi

13、nionLong PinionThis AOD-E gear set has four forward speeds plus reverse and neutral.Carrier25Simpson 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 Carrier26Four Sp

14、eed GearsetThis modern 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

15、 Gear27Shift ControlAutomatic transmissions 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.28Shift

16、 ControlAutomatic trans- missions use 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. 29Planetary OperationThis chart shows how a simple planetary gearset can produce six different gear ratios