Rack and pinions are used for lifting mechanisms (vertical movement), horizontal movement, positioning mechanisms, stoppers and to let the synchronous rotation of a number of shafts generally industrial machinery. However, also, they are found in steering systems to change the direction of cars. The features of rack and pinion systems in steering are the following: simple framework, high rigidity, small and lightweight, and exceptional responsiveness. With this mechanism, the pinion, installed to the steering shaft, is usually meshed with a steering rack to transmit rotary movement laterlly (switching it to linear motion) to ensure that you can control the wheel. In addition, rack and pinions are used for several other purposes, such as toys and lateral slide gates.
As a mechanical component to transfer rotary into linear motion, gear racks are often in comparison to ball screws. There are pros and cons for using racks instead of ball screws. The benefits of a gear rack are its mechanical simplicity, huge load carrying capacity, and no limit to the space, etc. One drawback though is 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 in fact the gear rack is stationary, while the pinion traverses and others where in fact 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 variants of rack and pinion, KHK has many types of gear racks in share. If the application requires a long length requiring multiple gear racks in series, we have racks with the tooth forms properly configured at the ends. They are Spur Gear Rack described as “equipment racks with machined ends”. Whenever a gear rack is produced, the tooth cutting procedure and heat treatment process can cause it to try & walk out true. We are able to control this with particular presses & remedial processes.