Adjustable-speed gear reducers provide simple and precise speed control across a wide range of applications.

　　 Adjustable-speed gearbox

　　Adjustable variable-speed gear reducers offer simple yet precise speed control across a wide range of applications. Speed can be easily adjusted by sliding the control lever along its arc or by turning the handwheel of the screw-type controller, providing a straightforward way to accurately regulate the ratio between output and input speeds.

　　We design and manufacture both unidirectional and reversible variable-speed drives that can accept any input and deliver output speeds of up to 2,000 RPM. Unidirectional drives rotate in one direction, while our reversible drives feature an output shaft capable of forward, neutral, or reverse operation. Adjustable-speed models offer clockwise or counterclockwise output rotation. We also provide gearboxes with right-angle configurations, ideal for low-speed, high-torque applications. Zero-Max drives are among the world’s most versatile and cost-effective secondary drive solutions.

　　Adjustable-speed gear reducers can deliver the precision and control you require. Please contact us to learn more about how we can meet your speed‑drive needs.

　　 Robust design and precise speed control

　　From the outside, the variable-speed drive consists of a robust, sealed cast‑aluminum housing, an input shaft, an output shaft, and a variable‑speed controller. The output shaft speed can be adjusted precisely and effortlessly via a control lever with a convenient locking mechanism or a screw‑type controller, allowing the speed to be maintained at the desired setting.

　　Compact structure and easy to operate.

　　Installation is simple. No special wiring or training is required.

　　It can be easily operated via a lever or screw. Reusable.

　　Use an adjustable-speed drive at any point on the machine. Accepts inputs of up to 2,000 RPM. An ideal auxiliary controller.

　　Provides constant torque across the entire speed range.

　　4:1 reduction. The drive can typically be used without additional reduction.

　　 Working principle of an adjustable-speed gearbox

　　The general operating principle of a variable-speed drive is to achieve continuously adjustable speed by varying the distance through which the output shaft rotates as the four or more one-way clutches reciprocate. The number of strokes per minute for each clutch is determined by the input speed. Since one revolution of the input shaft causes each clutch to move back and forth once, it is clear that the input speed dictates how many strokes—or pushes—the clutches impart to the output shaft each minute.

　　For example, when four clutches are connected in series and the input speed is 1800 RPM, the output shaft is driven 7200 times per minute (1800 × 4), or 120 times per second (7200 ÷ 60). If the input speed drops to 900 RPM, the shaft is driven only 3600 times per minute, and the maximum output speed is halved.

　　 Adjustable Variable-Speed Reducer Diagram  

　　The input assembly consists of a shaft (A), an eccentric cam (B), and a connecting rod (C), which converts rotary motion into linear motion. At the zero setting, the main connecting rod (D) rotates about points (H) and (J) without moving the clutch. At any setting other than zero, the clutch (E) converts the linear motion back into rotary motion and drives the output shaft (F). When the control lever is moved, the control connecting rod (G) swings along the arc (K).

　　At any point along the arc (K), a different output speed is produced, because the direction of the connecting rod’s oscillation changes from vertical (Figure 1, zero‑speed position) to horizontal (Figure 2, maximum‑speed position), thereby altering the stroke length transmitted by the main connecting rod to the overrunning clutch.