Differential Draw Transmissions

Differential Draw Transmission with Integral Phase Shifting Differential transmissions accomplish Primary Speed Control and Secondary Position Control. When the Speed Control screw of the unit is set to any position within its range the ratio between the input and output shafts are fixed or preset. The Secondary Position Control is accomplished by rotating the correction shaft which accesses the correction differential. This can accomplish an incremental correction which offsets the phase angle or controls position between the input and output shafts. These PIV chain drive transmissions are often used in pump drives, extractor drives, machine tool drives, screw conveyors, and winder drives, among other applications. In many cases, SPECON PIV transmissions or PIV chains products are fit, form and function interchangeable with units made by other manufacturers, such as Rexnord®, Link-Belt®, AC Compacting® or other manufacturers. Please contact the factory for interchange information concerning Link-Belt® PIV transmission units.

"TD" Geared Differential Transmissions and Differential Assemblies
Specon Differential Transmissions and Specon Differential Assemblies are compact rugged units, engineered to give reliable service over long periods of time in a wide variety of industrial applications. While usually supplied as either standard or special units composed of differential and associated gearing together with the necessary casing, the differential gearing alone is available as assemblies which can be incorporated in gearboxes of the user's own design. The input and output speeds and torques are governed by the capacity of the differential assembly appropriate to any particular unit and by the sizes of the internal gearing.
"HD" Harmonic Drive Draw Transmissions
Fairchild Harmonic Drive Draw Transmissions incorporate strain wave gearing principles which allow application of the unit in precise control of equipment. The Harmonic Drive has high torque capacity, zero backlash and high single stage ratio. The effect of tooth to tooth error is minimized with strain wave gearing since about 10% of the total teeth are always in engagement. This unit is an excellent choice for positional accuracy and repeatability in narrow draw applications (3.5% or less) such as web-offset printing.
"MD" Mechanical Differential Variable Speed Transmissions
Specon MD variable speed transmissions are complete units consisting of PIV chain style positive-drive variable speed mechanisms integrated in combination with gear boxes which incorporate bevel gear differential assemblies. The real advantage of these Specon MD style gearboxes, in the "MDX" and MDY" configurations, is their ultra-wide speed range capability. These PIV chain Differential transmissions are infinitely adjustable to ratios from zero RPM up to even 1,000,000:1. Typical applications for the MD variable speed transmissions include Lear drives, conveyors, glass drawing machinery, prime movers and winding machines.
"MDD" Mechanical Differential (STANDARD SPEED RANGE) Transmissions
"MDD" Mechanical Differential (STANDARD SPEED RANGE) Transmissions
The Specon Mechanical Differential Draw (MDD) Transmission differential draw design results in extremely accurate control of speed by compressing the speed range of a relatively wide mechanical variable speed device by appropriate connection to differential gearing. Inherent operating accuracies over 1000 times those of the variable element are attainable. This time-proven concept is combined with the service-proven components of the Specon MDD Transmissions to produce extremely accurate and reliable units with a long service life for Printing presses, paper machinery, film processing, paper cutoff, synthetic fiber, alternator drives, textile machinery, metering pumps and other Trim Speed applications requiring inherently high operating accuracy.