You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
<strong>Shaft</strong> <strong>Locking</strong> <strong>Devices</strong><br />
Other Considerations<br />
<strong>Shaft</strong> <strong>Locking</strong> <strong>Devices</strong><br />
• Minimum outer diameter of hub<br />
The hub must be of a size to withstand the pressure exerted by the <strong>Shaft</strong> <strong>Locking</strong> Device<br />
without yielding. Use the following equations to determine<br />
the minimum hub diameter (Dmin) required.<br />
Dmin = D "<br />
Yp + ( f × pH )<br />
Yp − ( f × pH )<br />
Where: D = Hub bore (inches)<br />
= Yield point of hub material (psi)<br />
Yp<br />
f = Form factor (see figure 1.)<br />
pH = Contact pressure on the hub (psi)<br />
f =0.6<br />
f =0.8<br />
• Combined torque and axial loads<br />
If an axial load is present, then the resulting torque that can be transmitted<br />
needs to be adjusted as follows:<br />
f =1<br />
Dh<br />
Dh<br />
Dh<br />
D<br />
D<br />
D<br />
Figure 1.<br />
Mt Result =<br />
Mt<br />
2<br />
⎛ F × d<br />
24 ⎟ ⎞<br />
+ ⎜<br />
⎝ ⎠<br />
2<br />
Where: d = shaft diameter (inches)<br />
Mt = maximum torque for device (ft-lbs)<br />
F = force (lbf)<br />
• Coefficients of friction and surface finish<br />
Lovejoy SLD uses µ = 0.12 which corresponds to a slightly oiled surface<br />
63 = 63 µIN RMS for surface finish<br />
• Duty factor<br />
The values Mt and F must be adjusted with a duty factor depending on the setup:<br />
Load<br />
Motor type<br />
Constant Light overloads Heavy overloads<br />
Electric<br />
1 1.5<br />
2<br />
Combustion<br />
1.5<br />
2<br />
2.5<br />
• Multiple <strong>Shaft</strong> <strong>Locking</strong> <strong>Devices</strong> used in series<br />
If more than one <strong>Shaft</strong> <strong>Locking</strong> Device is used, the transmissible torque<br />
must be reduced by the following factors:<br />
<strong>Shaft</strong> <strong>Locking</strong> Device<br />
SLD 1500<br />
SLD 1850<br />
SLD 1350<br />
SLD 2600<br />
Number of devices in series<br />
2 3 4<br />
.80 .75 .70<br />
.80 .75 .70<br />
.80<br />
.85<br />
.75 .70<br />
Not recommended<br />
www.lovejoySLD.com<br />
23