LD wheel, wheel group, drum group, hook group, pulleys, couplings, wire rope, cable pulley, motor, brake, reducer, cable reel, overload limiter, standard parts.

It points out that the position of the maximum strain, stress and tension is at first group trough type roller, not at passing poion of pulley if the head drum works as pulley.

The tower type belt driven long stroke pumping unit is composed of the crank-linkage-slide mechanism, movable pulley-narrow belt-fixed pulley mechanism and compound drum stroke-increment mechanism.