Horton variable-speed fan drives usually feature viscous, or fluid, technology. In general, a variable-speed drive operates in accordance with the cooling requirements to maintain the engine at an optimal operating temperature. When less cooling is required, it operates at a low idle speed, allowing for faster warm-up times, higher internal temperatures, significant noise reduction, more available power, and lower fuel consumption. As more cooling is required, it accelerates faster, smoother, and with less stress on the drive, motor, and adjacent components. It is also maintenance-free (no friction liner) and helps OEMs meet Tier 4 requirements. Variable-speed operation also helps reduce fan abrasion from dirt, stones, and other debris as the fan clutch operates at lower speeds and runs fewer and shorter cycles. Variable-speed fan clutches are available in a variety of sizes for a variety of applications, including medium- and heavy-duty trucks, commercial vehicles, buses, specialty off-highway vehicles, and many off-highway applications.
