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DESCRIBING NONSTANDARD GEARS ..
(continued from page 20)
Derivation of Equation 5:
p'
p'
011 (tbl - inv¢') + 01 2
(. th2. - inve') +B'
ObI 0"2.
p' tbl ..., 0'2 tb2 D'2 . , B'
-----mv¢ +-----mv¢ +-
0'1 Dbl D'l ~1 OIl D'l
L_Ph
D\ ObI
0'2 Db2
----
Crossed
Conditions:
Axis Gears
• Axis are in parallel
planes.
• N ormal operating circular pitches are equal
• Normal operating pressure angles are equal.
• Sum of normal operating tooth thicknesses plus normal
circular backlash equals operating normal circular pitch.
Derivation of Equation 12:
Given: tOnI' tbn2' a, N1, Nz, PN, Px1 and Px2
Note that axial pitches are different fo,r the two gears.
OIl Dj,1
Note: B~is transverse backlash at 0 1 ,
B is transverse backlash in plane of action.
for
each gear:
j
1I'D
N
t'n -
t't coS¢'
ttb _ 'I' tnb
OJ,
NPN
_ N p'n..
O'COSlP'
'IT
D'lCOS¥/'l
, ;, ., 11' tnhl '.' . ..' r tnbz. ,
Pn-DICOSlPl(•.- -mv¢tl)+D2c.oSlPz(-.--mv¢t2)+B n
N1Pn.
NzPn
., _, (tnbI+tnb2) Pn'N
I,
,'N
A.' P.n-2._ A.' +·B
Pn-Pn - -. - --mv"'·t1 - --mv"'t2 ·n
PN PN 11' 11'
, tnbl tnb2 Nl.. j N2. , B n
l---+----Invcf> n--InvrP t2+-
PN PN 11' 11' p'n
NI
N!!.I!'U! you r ,!!,ppUc:atlonl
FRO.MAG Keysealers. offer:
- keyway width Irom"," - 6"
- keyway length up to 71 ..
- CIIIling s~ stepless adiustable
fromO-·SSH.
- return speed stepless adjustable
fromO-150ft.
- tangential, tapered, multiple keyways
- .intemal and helical splines
- oil grooves
- squares, hexagon
- slotting with guided tool (blind hole cutting)
- optional tool retraction
(Bn_BN)
p'n
Pn
TINI +T2N2+'l: BN
PN
tbl tb2 BN
or . -=NIL )+N 2 (- .. -+ 11' (-)- 'II'
ObI Db2 PN
(22)
(12)
Maschinentabrik
FRD.MAGGmb'H
0-5758 FrOndenDerg· W-Germony . Tele.~; 8202622· Telara)(; (02373) 75633
iFRCMAG C/O . R.J. Kemp cmd As~late$· SAl
36 W 610 Lake Cha~one C1. . 51. Charles, Ill. 60 174 . Tal, 312-584-448a
CIRCLEA-4 ON READER,REPLYCARD
Tooth Thickness (See Fig. 8.)
Derivation of Equation 13:
Rl is the radius
where:
"t" - tooth thickness is equal to "s" - tooth space.
¢1 is the pressure angle at that radius.
~ is the base circle radius.
22 Gear Technol.ogy