APTD ( Twin Disc )

All Power-Transmission Inc. purchased the design, equipment and manufacturing rights to the Twin Disc J-line of universal joints in March 2000.  Building on the nearly half century of experience by Twin Disc, All Power is now producing universal joints to the same exacting standards as the original Twin Disc.

Available Twin Disc Models

Twin Disc is now designated as AP Twin Disc. All Power-Transmission Inc. now has available seven sizes of Twin Disc industrial U-joints with different types of Twin Disc in each size.

• J-170 Twin Disc
• J230 Twin Disc
• J-310 Twin Disc
• J-490 Twin Disc
• J-600 Twin Disc
• J-800 Twin Disc
• J-1200 Twin Disc

The types vary according to range and method of accommodating axial slip.  Capabilities range from 4250 lbs.-ft. to 26,000 lbs.-ft. rated static torque.  The static brinell capacity of the roller bearings in the U-joint is approximately twice the rated capacity of the joint.  The yield point of the yokes and cross in the U-joint is approximately 21/2 times the rated capacity.  The yield strength varies with the yoke design.

APTD Twin Disc Features

APTD Twin Disc Model J Series U-joints in sizes J-170 to J1200 all use high-wing bearing cap design exclusively.  High wing construction provides longer capscrews for attaching the bearing caps.  These longer capscrews will remain tight under the most severe operating conditions.  High-wing bearing caps, together with externally wrenched capscrews permit use of a larger diameter bore in the cap, thus accommodating a larger bearing.  This larger bearing assures longer U-joint life for a given swing diameter.

Wing-type bearing cap design also provides a lighter and more serviceable assembly.  Since companion flanges are not required as in round bearing types, the centerline of the U-joint is closer to the bearings in both driving and driven machinery.  Thus, overhanging loads are minimized.

The sizes J-230, J-310, J-600 and J800 twin disc U-joint models are interchangeable with wing-type U-joints of other manufacturers.  APTD (twin disc) U-joints, however, offer greater dynamic ratings than other U-joints of equivalent size.  The dynamic factor is a measure of the U-joint's life. It indicates the ability of the U-joint to transmit a given power through a specified U-joint angle at a certain speed for a specified number of hours.

Since the life of the U-joint is really an expression of the life of the roller bearings, the dynamic factor of the U-joint can be calculated from a formula based on modifications of basic roller bearing formulas.  APTD (twin disc) design emphasis in this area has resulted in the adoption of larger diameter accurately guided roller bearings as standard.  Larger bearings mean greater life expectancy for a given swing diameter- an important consideration to designers and users who are now experiencing unsatisfactory U-joint performance yet do not have space for a larger size.

In choosing U-joints for any industrial application, bear in mind this fact: APTD (twin disc) calculates a U-joint lifespan based on four variables- torque, speed, angularity and application factors.  For this reason, you can choose a Twin Disc U-joint design to match the predicted lifespan of the other components in your drive system.

This area of the web site has been prepared to assist designers in making tentative size selections- however, trained factory Application Engineers are available in Green Bay, Wisconsin, to assist in solving universal joint application problems. Also, All Power factory authorized agents and distributors are available to make specific recommendations on Twin Disc U-joint applications.  In addition, All Power Engineers are available to make special designs for specific applications.