Racks & Pinions
Sometimes, the best way to move something is to drive a gear rack with a pinion. Rack and pinion gear sets are designed to convert rotational motion into linear motion.
The circular gear (call the “pinion gear“) engages the teeth on a linear bar (called the “gear rack“). Rotational motion is applied to the stationary pinion gear, which causes the gear rack to move. Thus, the rotational movement of the pinion gear is transferred to the linear motion of the gear rack.
- Custom Gear Racks
The gear rack is a long, straight bar with teeth along its entire length. The teeth have the same pitch as the pinion gear which engages with it.
- Custom Pinions
As the pinion gear is turned, its gears mesh with the gear rack, creating linear torque.
Custom rack and pinion designs are based on many factors, including design constraints. Among these considerations are cost, accuracy, load requirements and peak cycle forces. These cycle forces depend on the weight being moved, the speed versus time provided for the cycle, the friction of the axis bearings and the external forces that act on the axis.
Observe the diagram below to note the required specs needed to begin manufacturing a custom rack and pinion. Three additional components need to be considered for accuracy: Backlash, Pitch Deviation and Tooth Quality.
Rack Quality Levels are selected for certain types of applications – and they also denote accuracy of the teeth. Tooth Quality is the accuracy of the manufactured tooth flanks. Tooth accuracy affects backlash, the positioning accuracy, as well as the noise level of the rack and pinion set. Backlash is the amount of clearance between the rack and pinion tooth flanks. Pitch Deviation is the difference between the theoretical rack length and its actual length.
From custom long gear racks to large drive pinion gears, your heavy-duty machining projects may need Cogmatic Flame Machining Technology to achieve enhanced application longevity, quality and affordability. Cogmatic has manufactured many clients’ large custom-designed racks and pinions that move their projects, ranging from furnace doors to blast hole drills.