Advantages of Different Transmissions ME350 Advantages of Chain Drives Shaft center distance variation may be more easily accommodated than with gear drives ● Easier to install and replace than belts because the center distance between driven and driver units need not be reduced for installation(splice and link belts overcome this objection at the cost of lower power ratings). Require no tension on slack side,so bearing loads are reduced. Do not slip or creep as do belt drives (except for toothed belts). Chain drives are more compact because sprocket diameters are smaller and chains are narrower than sheaves and belts for the same power transfer. Chains do not develop static charges Chains do not deteriorate with age,heat or oil and grease. Chains can operate at higher temperatures than belts. 6
ME 350 6 Advantages of Different Transmissions 4 Advantages of Chain Drives • Shaft center distance variation may be more easily accommodated than with gear drives • Easier to install and replace than belts because the center distance between driven and driver units need not be reduced for installation (splice and link belts overcome this objection at the cost of lower power ratings). • Require no tension on slack side, so bearing loads are reduced. • Do not slip or creep as do belt drives (except for toothed belts). • Chain drives are more compact because sprocket diameters are smaller and chains are narrower than sheaves and belts for the same power transfer. • Chains do not develop static charges • Chains do not deteriorate with age, heat or oil and grease. • Chains can operate at higher temperatures than belts
Advantages of Different Transmissions ME350- Advantages of Gear Drives Gear drives are more compact than chain or belt drives because center distances are minimum. Gears have greater speed capabilities than either belts or chains. Gears have a greater range of speed ratios than chains. Gears can better transfer high power at high speed than can either belts or chains. Metal gears do not deteriorate with age,heat or oil and grease and they do not develop static electric charges. 7
ME 350 7 Advantages of Different Transmissions 4 Advantages of Gear Drives • Gear drives are more compact than chain or belt drives because center distances are minimum. • Gears have greater speed capabilities than either belts or chains. • Gears have a greater range of speed ratios than chains. • Gears can better transfer high power at high speed than can either belts or chains. • Metal gears do not deteriorate with age, heat or oil and grease and they do not develop static electric charges
Gears4 ME350- (a) (b) (c) () (d) (e) Figure 13.0.1(a)Spur gear.(b)worm gear.(c)helical gear,(d)rack,(e)internal gear,and(f)straight 8 bevel gear.Source:Boston Gear,Quincy,MA
ME 350 8 Gears 4
Basic Gear Types5 ME350 .There are four main types of gears: >Spur Gears Helical Gears Bevel Gears >Worm Gears 9
ME 350 9 Basic Gear Types 5 •There are four main types of gears: ¾Spur Gears ¾Helical Gears ¾Bevel Gears ¾Worm Gears
Basic Gear Types -Spur Gears ME350— These gears have teeth parallel to the axis of rotation and are used to transmit motion and power from one shaft to another parallel shaft. 10
ME 350 10 Basic Gear Types – Spur Gears These gears have teeth parallel to the axis of rotation and are used to transmit motion and power from one shaft to another parallel shaft