Nomenclature5 ME350 Diametral pitch(径节)，P The ratio of the number of teeth on the gear to the pitch diameter. This is the reciprocal of the module and is expressed in teeth per inch for U.S.units.Only used for U.S.units W P d 36
ME 350 36 Nomenclature 5 d N P = •Diametral pitch(径节), P ¾ The ratio of the number of teeth on the gear to the pitch diameter. ¾ This is the reciprocal of the module and is expressed in teeth per inch for U.S. units. Only used for U.S. units
Nomenclature5 ME350— .Addendum,a Radial distance between the top land and the pitch circle.a 1/P for standard teeth .Dedendum,b >Radial distance from the bottom land to the pitch circle.b 1.25/P for standard teeth .Center Distance(C) The distance from the center of the pinion to the center of the gear The sum of the pitch radii of two gears in mesh. 37
ME 350 37 Nomenclature 5 •Addendum, a ¾ Radial distance between the top land and the pitch circle. a = 1/P for standard teeth •Dedendum, b ¾ Radial distance from the bottom land to the pitch circle. b = 1.25/P for standard teeth •Center Distance (C) ¾ The distance from the center of the pinion to the center of the gear ¾ The sum of the pitch radii of two gears in mesh
Nomenclature5 ME350- Backlash The amount by which the width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circles. (space width of one gear)-(tooth thickness of other gear) 38
ME 350 38 Nomenclature 5 •Backlash ¾ The amount by which the width of a tooth space exceeds the thickness of the engaging tooth measured on the pitch circles. (space width of one gear) - (tooth thickness of other gear)
Tooth Nomenclature5 ME350 Face width Top land Addendum circle Face Addendum Circular pitch Tooth Width Pitch Dedendum thickness Flank of space circle Bottom land Clearance 《《 Fillet radius Dedendum circle Clearance 39 circle
ME 350 39 Tooth Nomenclature 5
Nomenclature5 ME350— Whole depth,h The radial distance from the top of a tooth to the bottom of the tooth space h;=a+b Working depth,hk The radial distance that a gear tooth projects into the tooth space of the mating gear hk=2a ·Clearance circle Circle that is tangent to the addendum circle of the mating gear. 40
ME 350 40 Nomenclature 5 • Whole depth, h t ¾The radial distance from the top of a tooth to the bottom of the tooth space h t = a + b • Working depth, h k ¾The radial distance that a gear tooth projects into the tooth space of the mating gear h k = 2 a • Clearance circle ¾Circle that is tangent to the addendum circle of the mating gear