File:Worm gearing (1916) (14595223150).jpg

Identifier: wormgearing00thom (find matches)
Title: Worm gearing
Year: 1916 (1910s)
Authors: Thomas, Hugh Kerr
Subjects: Gearing, Worm
Publisher: New York : McGraw-Hill Book Co.
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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rium 0.07 0.06- g0.05o m0.04 6 0.03 0.02 0.01 i\t;, ar w — \\V ^V = 19.34 i.p .s. w c ^ \ Y ^=28.3 J / V / e \ !^ to.85^ x^/ \\\ f^ y y -^ y - \ i\\ \, -- / V V\ \ ,/ / / Tv^\ V = 9.8 / / / \ / / / Tx > \^ V= = 4. 62 t I / / / / vS^ S -6- >// A / ^>^ - J^ X kxVJ b^^ y y / ^ r^ .-- ^ 4 = 2.5^ BACH & ROSERRelation between Pressure, Velocityand Coefficient of Friction — 500 1000 1500 2000 Tangential Tooth Pressures - Lbs.Fig. 27. 2500 3000 was established. The mechanism being set in motion by hand,weights were added to the cord on the worm drum until a con-stant speed of rotation could be maintained. On substituting heavier weights, it was found that a greaterweight was needed to keep the wheels in motion, and, severalobservations being thus made, a number of values w^ere obtainedfor the weight necessary to maintain uniform motion withdifferent degrees of tooth pressure. Plotting these values atordinates, upon tooth pressures as abscissae, it was found that 66 WORM GEARS
Text Appearing After Image:
00 ^ EFFICIENCY OF WORM GEARING 67 these fell in a straight line as shown by the line A (Fig. 29)The observed points being TABLE VII Pressures x Load to overcome friction y 2 1b.4 1b.8 1b. 3.754.756.75 It is evident that the loads y are the product of a;X/^ Curves showing Values of jJ- from Observed Friction Readingsfrom Observed Points. V = Xti &. 2y-X=5.5 .. 2XfJi.-x=5.5fi approaches V2 as a Limit as X approaches coH .. CO .. .. « ., .. .. Zero. 7 / 6 3. 3 / ■?. n / f h 01 -) / A 0 V f •m 4o / y / s / 1 ^z \ 2X \ I 1 \ ^ ■—. n 2 4 6 8 10 20 30 Pressure in #iC Fig. 29. 40 50 The equation to a straight line is 2y — x = 5.5.*. 2xfi — x = 5.5 5.5 + x Fig. 29 shows the curve to this equation giving values of /xfor various pressures x, from which we see that 68 WORM GEARS (i approaches . 5 as a limit as x approaches c-oH approaches oo as a Hmit as x approaches o. Turning again to Beauchamp Towers experiments, thecurves in Fig. 30 show the relationship between bearing pres

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