Rack and pinions are used for lifting mechanisms (vertical movement), horizontal motion, positioning mechanisms, stoppers and to let the synchronous rotation of several shafts in general industrial machinery. On the other hand, they are also found in steering systems to improve the direction of vehicles. The features of rack and pinion systems in steering are the following: simple framework, high rigidity, small and lightweight, and excellent responsiveness. With this mechanism, the pinion, Spur Gear Rack mounted to the steering shaft, is definitely meshed with a steering rack to transmit rotary movement laterlly (transforming it to linear motion) to ensure that you can control the wheel. In addition, rack and pinions are used for many other purposes, such as toys and lateral slide gates.
As a mechanical element to transfer rotary into linear movement, gear racks are often in comparison to ball screws. There are pros and cons for using racks in place of ball screws. The benefits of a equipment rack are its mechanical simplicity, large load carrying capacity, and no limit to the distance, etc. One disadvantage though may be the backlash. The advantages of a ball screw will be the high precision and lower backlash while its shortcomings include the limit in length due to deflection.
There are applications where the gear rack is stationary, while the pinion traverses and others where the pinion rotates on a fixed axis as the gear rack moves. The previous is used widely in conveying systems as the latter can be used in extrusion systems and lifting/lowering applications.
To provide many variations of rack and pinion, KHK has various kinds of gear racks in share. If the application requires a long length requiring multiple equipment racks in series, we’ve racks with the tooth forms correctly configured at the ends. They are described as “equipment racks with machined ends”. When a equipment rack is created, the tooth cutting procedure and heat treatment process can cause it to try & go out of true. We are able to control this with special presses & remedial processes.