70 SURFACE MACHINERY AND METHODS FOR OIL-WELL PUMPING.
BEVEL GEAR AND DISK TYPE
Small powers of the bevel gear and disk type consist of pulley,
shaft, beveled gear and pinion, wrist pin, and disk mounted on a cast-
iron bed plate, with the large gear placed to revolve in a horizontal
plane. Usually, three wrist-pin adjustments on the upper face of
FIGURE 10.-Small spur gear and crank-arm type of power.
the gear permit three different positions of the disk with reference
to the gear axis, and thus allow three different lengths of stroke.
These powers are light, strong, and compact and are well suited for
pumping two to six shallow wells. The disk on the wrist pin wears
rapidly, however, unless enough bearing surface is insured by using
George, H. C. Surface Machinery and Methods for Oil-Well Pumping. Washington D.C.. UNT Digital Library. http://digital.library.unt.edu/ark:/67531/metadc12407/. Accessed March 5, 2015.