Adjustable Speed Drives

Adjustable Speed Drives Available at Zero-Max

Zero-Max designs and manufactures two types of adjustable speed drives, including unidirectional and reversible (bi-directional) drives, depending on the application. Unidirectional adjustable speed drives offer an output shaft that rotates in only one direction. Reversible adjustable speed drives feature an output shaft that can be operated in forward, neutral, or reverse directions. All adjustable speed drive models are available with output in clockwise or counterclockwise rotation, and contain a rugged, sealed case, input shaft, output shaft, and adjustable speed control. Zero-Max also provides drive accessories to achieve exact performance characteristics in many applications.

Adjustable Speed Drive Operation
 

The adjustable speed drives from Zero-Max provide smooth, infinitely adjustable speed by internally changing the distance that four or more one-way clutches rotate the output shaft when moving back and forth successively. The number of strokes per clutch, per minute, is determined by the input speed. Since one rotation of the input shaft causes each clutch to move back and forth once, it is readily apparent that the input speed will determine the number of strokes (or urgings) the clutches give the output shaft per minute.

For example, with four clutches working in series and an input of 1800 RPM, the output shaft is urged 7200 times per minute (1800 x 4) or 120 times per second (7200 ÷ 60). If the input speed is dropped to 900 RPM, the shaft is urged only 3600 times per minute and the maximum output speed will be cut in half.

Looking at Figure 1, the input section, consisting of a shaft (A), eccentrics (B), and connecting rods (C), converts rotary motion into linear motion. At the zero setting, the main links (D) pivot on points (H) and (J) without moving the clutches. At any setting other than zero, the clutches (E) transfer the linear motion back into rotary motion and drive the output shaft (F). A control link (G) swings through arc (K) when the control lever is moved.

At any point along arc (K) a different output speed is produced because the direction of throw of the connecting rod is altered from vertical (Figure 1 zero RPM position) toward horizontal (Figure 2 maximum speed position), varying the length of the strokes the main links deliver to the overrunning clutches.

Adjustable Speed Drive Features

The compact size of Zero-Max Adjustable Speed Drives make them easy to handle and the simple lever or screw control make them easy to operate.  They are also simple to install with no wiring or special training required. In addition, varying with the model and type used, many accessories can assist with modifying the desired performance. Several optional features from Zero-Max drive accessories include:

• Selection of gearheads and motors for Model E and JK Drives
• C-Flange adaptors are available for Models Y and QX drives to connect customer-supplied motors to the selected drive
• Optional screw control, extended screw control, extended lever control, extended control shaft, and flatted and drilled control levers in addition to the standard lever control on all drives
• Reversible models of output rotation and input direction with CCW output for models ending in “1”, CW output for “2”, and reversible for “3”

Advantages of Adjustable Speed Gearboxes

Adjustable speed drives are ideal for users and original equipment manufacturers and contain many advantages to increase performance. Output shaft speed is regulated precisely and easily through a control lever with a convenient locking mechanism or a screw control to hold the speed at the desired repeatable setting. The low-cost, proven design has benefited users for more than 1,000,000 installed and counting. Several advantages of Zero-Max Adjustable Speed Drives include:

• Easy to install and operate
• Use anywhere on the machine with input speeds up to 2,000 RPM
• 4:1 speed reduction without the need for additional speed reduction
• Infinitely adjustable at 0-400 RPM speed range ( assuming 1,800 RPM input)
• Goes to zero output, ideal for use as a clutch
• Accurate speed holding with no “wear-in” period/constant speed operation.
• Sealed housing to be used in most atmospheres
• Simple maintenance and factory lubricated
• Leave the drive at one setting for no daily speed cycling

Adjustable Speed  Drives for Many Applications

The adjustable control options and shaft arrangements of Zero-Max Adjustable Speed Drives ensure top performance in many industries and applications. The adjustable speed drives can operate as primary or secondary drives and are versatile with many types of machinery. Several applications of Zero-Max Adjustable Speed Drives include:

• Textile machinery such as looms
• Food processing machinery such as hamburger presses
• Agricultural machinery including grain dryers and seeder drives
• Printing presses for high-speed sheeters
• Industrial machinery
• Packaging systems
• Materials handling machinery

Zero-Max is Your Adjustable Speed Drive Manufacturer

For over 75 years, Zero-Max has designed and engineered high-quality adjustable speed drives and other power transmission products from our skilled team of engineers. Through innovative designs and premium products, manufactured with state-of-the-art technology, we are sure to provide the ideal variable speed drive for you. We offer extensive customization capabilities and resources to ensure that no application is too unique or demanding for our products. See why Zero-Max is your top adjustable speed drive manufacturer for any need!

Contact Us for Your Adjustable Speed Drive Needs

With unidirectional and reversible adjustable speed drives, along with many accessories to customize the desired performance, we are sure to deliver the right adjustable speed drive solution for any challenge. Contact us for more information about our variable speed drives or request a quote for more detailed pricing options.

Choose an industry below for application-specific examples of how our Adjustable Speed Drives help you achieve better precision and control.