GEAROLOGYTABLE OF CONTENTSTABLE of CONTENTS II pot

GEAROLOGY Chapter 1 Introduction to Power Motion Products . . . . .1-1 Chapter 2 Spur Gears . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1 Chapter 3 Helical Gears . . . . . . . . . . . . . . . . . . . . . . . . . . .3-1 Chapter 4 Worm and Worm Gears . . . . . . . . . . . . . . . . . .4-1 Chapter 5 Bevel and Miter Gears . . . . . . . . . . . . . . . . . . .5-1 Chapter 6 700 Series Worm Gear Speed Reducers . . . . .6-1 Chapter 7 800 Series Helical Speed Reducers . . . . . . . . .7-1 Chapter 8 Introduction to Ratiotrol . . . . . . . . . . . . . . . . .8-1 Chapter 9 AC Inverters . . . . . . . . . . . . . . . . . . . . . . . . . . .9-1 Chapter 10 Centric Overload Release Clutches . . . . . . . .10-1 TABLE of CONTENTS TABLE OF CONTENTS [...]... • Velocity of pinion = 1,800 rpm • Velocity of gear = 600 rpm • Service factor = 1.25 Step 1 – Find the pitch diameter (PD) of the pinion and gear (assuming the center distance and ratio are fixed) using the following formulas: PD of pinion = 2 x center distance ÷ ratio + 1 PD of gear = PD of pinion x ratio Now let’s insert the figures from our sample set of variables and do the math: PD of pinion =... beginning to the end of contact DEDENDUM (b) is the depth of a tooth space below the pitch line It is normally greater than the addendum of the mating gear to provide clearance DIAMETRAL PITCH (P) is the ratio of the number of teeth to the pitch diameter FACE WIDTH (F) is the length of the teeth in an axial plane FILLET RADIUS (rf) is the radius of the fillet curve at the base of the gear tooth FULL... and thrust RATIO The ratio of a pair of helical gears may be determined from the shaft speed or the number of teeth in the two gears Ratio = RPM of Driving Gear ÷ RPM of Driven Gear Example: Ratio = 900 ÷ 900 = 1 Ratio = No of Teeth in Driven Gear ÷ No of Teeth in Driving Gear Example: Ratio = 12 ÷ 12 = 1 ROTATION In a helical gear train with an even number (2, 4, 6, 8, etc.) of gears in mesh, the first... modification of a tooth profile whereby a small amount of material is removed near the tip of the gear tooth PINION is a machine part with gear teeth When two gears run together, the one with the smaller number of teeth is called the pinion UNDERCUT is a condition in generated gear teeth when any part of the fillet curve lies inside a line drawn tangent to the working profile at its point of juncture with the... corresponding profiles of adjacent teeth KEYWAY is the machined groove running the length of the bore A similar groove is machined in the shaft and a key fits into this opening CIRCULAR THICKNESS (t) is the length of arc between the two sides of a gear tooth on the pitch circle, unless otherwise specified NORMAL DIAMETRAL PITCH (P n ) is the value of the diametral pitch as calculated in the normal plane of a... pinion and driver will rotate in opposite directions When there is an odd number of gears, the pinion and driver GEAR RATIO the mathematical ratio of a pair of spur gears – will rotate in the is determined by dividing the number of teeth on the larger gear with the number of teeth on the pinion same direction Example: The ratio of a 72-tooth gear running with a 16-tooth pinion is 4.5:1 Ratio: 72÷16 = 4.5... noise, abnormal wear and excessive section of your Boston Gear heat while providing space for lubrication of the gears (See Figure 2.6) catalogs DRIVEN CENTER DISTANCE DRIVER PITCH CIRCLES BACKLASH EXAGGERATED Figure 2.6 PITCH CIRCLES SHAFT 1" PITCH CENTER DISTANCE is the distance between the center of the shaft of one spur gear to the center of the shaft of the other spur gear In a spur gear drive... (Db) is the diameter of the base cylinder from which the involute portion of a tooth profile is generated BACKLASH (B) is the amount by which the width of a tooth space exceeds the thickness of the engaging tooth on the pitch circles As actually indicated by measuring devices, backlash may be determined variously in the transverse, normal, or axial-planes, and either in the direction of the pitch circles... standard gear-tooth proportions WHOLE DEPTH (ht) is the total depth of a tooth space, equal to addendum plus dedendum, equal to the working depth plus variance WORKING DEPTH (hk) is the depth of engagement of two gears; that is, the sum of their addendums TOOTH PARTS PINION PINION PITCH CIRCLE LINE OF ACTION OUTSIDE DIA PRESSURE ANGLE TOOTH PROFILE (INVOLUTE) BASE CIRCLE PITCH CIRCLE WHOLE DEPTH WORKING... PITCH The transverse pitch of a helical gear corresponds to the pitch of a spur gear with the same number of teeth and the same pitch diameter It is measured in the plane rotation of the gear (See Figure 3.3C) 14 1/2-degree normal pressure angle Transverse diametral pitch (D.P) = 3.1416 (Transverse circular pitch (C.P.) NORMAL PITCH The normal pitch of a helical gear is the pitch of the tool used to cut . providing space for lubrication of the gears. (See Figure 2.6) CENTER DISTANCE is the distance between the center of the shaft of one spur gear to the center of the shaft of the other spur gear. In. the mathematical ratio of a pair of spur gears – is determined by dividing the number of teeth on the larger gear with the number of teeth on the pinion. Example: The ratio of a 72-tooth gear running. familiar with some of the basics of power transmission – keeping in mind that you should have a complete set of Boston Gear catalogs nearby for quick reference. There are a number of variables to