Timing belts and pulleys have matching
teeth to maintain synchronism between driving and driven wheels. The
teeth prevent the belt from slipping. Timing belts are designed to not
stretch. Stretching a timing belt while installing it will damage it.
The pitch is the distance between the teeth of a toothed
belt, chain, sprocket, or gear. The pitch of these
particular pulleys is 1/5" (one-fifth of an inch). In order for a belt
to engage the teeth of the timing pulley, both parts must have the same
pitch. The bore diameter of a pulley or gear is the diameter
of the hole in the middle. The bore of the pulleys and bearings in this
display are 1/4" (one-fourth of an inch; pronounced "quarter
inch"). The pulley is secured to the shaft (or axle)
by a set screw.
It should be noted that the rotational speed of this display is very
slow. The fan does not blow any air.
See the Round Belt Drive page for a
general introduction to belts and pulleys and the drive ratios page for another demo using
timing belts.
|
The timing belts and pulleys shown here
are from Small Parts, Inc., and SDP-SI, both listed in the sources
page.
|
|
