Drive System

Lecture-1 Drive SystemBijoy Dripta Barua ChowdhuryLecturerDepartment of IPE,BUETCone Pulley DriveAdvantagesCan Absorb shockHigh mechanical efficiencySmooth running

DisadvantagesLarge number of step is not availableTime for setting speed is high

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.Properties of Cone Pulley driveIf the central distance of the two cone pulley is larger than 10(d max d min )and summation of diameter pair is constant then the belt remain tight for all position.Transmitted power varies with different belt position. To avoid much variation of power and toque, the drive should be designed so thatADVANTAGES OF ALL-GEAR SPINDLE DRIVEOVER CONE PULLEY DRIVE.High power transmission.Quick speed change though levers.compact and require less floor space.METHOD OF SPEED CHANGINGSlip gear The mating gear pair on two adjacent shaft are interchanged or replaced by another pair of gears. The condition for the interchangeability T1 + T2 = T3 + T4 = T5 + T6SLIDING KEY METHODTwo sets of gear on two shaft are constantly in mesh. One set is free to rotate on the shaft. Only one gear of free set is engaged by a sliding key

Sliding KeyTUMBLER GEARA number of gear is placed in one shaft which is at fixed distance from the output shaft. Used usually for feed drives an known Norton gearbox.

SLIDING TYPE CLUSTER GEARA set of cluster gear is moved along a shaft to engage another set of gears (one gear cluster is fixed at a time).

Basic Principles for designing Cluster GearRule - 1One set of gears in mesh must completely disengage before next pair of gears come into contactRule 2The difference in the number of teeth of adjacent gears of a cluster must be at least 4 (assumed that all gears have the same module)TI2 TI3 4JAW CLUTCHESSpeed can be changed by engaging and disengaging clutches with levers.Advantages of this speed changing method-

They require small axial movement.Helical and herringbone gear can be used.Force required to shift them less than that for sliding cluster gear

FRICTION CLUTCHESLimiting torque capacityHigh frictional loss and overheatingHigh torque capacitylarge axial and radial dimension

1Cones: female= green, male= blue2Shaft: male cone is sliding on splines3Friction material: usually on female cone, here on male cone4Spring: brings the male cone back after using the clutch control5Clutch control: separating both cones by pressing6Rotating direction: both direction of the axis are possibleDESIGNING OPTIMUM GEAR BOXProduction costShaft lengthFrictional lossMass moment of inertiaTYPE OF FEED GEAR BOXFeed gearbox with slip gearsFeed gearbox with slip gear quadrantFeed gearbox with sliding gearsFeed gearbox with sliding keyNorton gearboxMeander gearboxINFINITELY VARIABLE DRIVEAdvantages possible to attain optimum cutting conditionImportant in reduction of handling time, because speed, feed can be changed without stopping the machine. Constant cutting speed can be obtained for stepped shaft and irregular contour.Tool life is improved and high surface finish.Reduce vibration and noiseless.WUELFEL KOPP TOURATOR

P.I.V(POSITIVE INFINITELY VARIABLE)DRIVE

P.I.V(POSITIVE INFINITELY VARIABLE)DRIVE

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