Rack and pinions are used for lifting mechanisms (vertical movement), horizontal movement, positioning mechanisms, stoppers and to let the synchronous rotation of many shafts in general industrial machinery. On the other hand, also, they are used in Spur Gear Rack steering systems to improve the direction of cars. The features of rack and pinion systems in steering are as follows: simple structure, high rigidity, small and lightweight, and excellent responsiveness. With this system, the pinion, mounted to the steering shaft, is meshed with a steering rack to transmit rotary movement laterlly (converting it to linear movement) to ensure that you can control the wheel. Furthermore, rack and pinions are utilized for various other purposes, such as toys and lateral slide gates.
As a mechanical element to transfer rotary into linear movement, gear racks are often compared to ball screws. There are benefits and drawbacks for using racks in place of ball screws. The benefits of a gear rack are its mechanical simplicity, large load carrying capacity, no limit to the space, etc. One drawback though may be the backlash. The benefits of a ball screw will be the high precision and lower backlash while its shortcomings include the limit in duration due to deflection.
There are applications where the gear rack is stationary, as the pinion traverses and others where the pinion rotates on a fixed axis as the gear rack moves. The former is used broadly in conveying systems as the latter can be utilized in extrusion systems and lifting/lowering applications.
To provide many variants of rack and pinion, KHK has various kinds of equipment racks in share. If the application requires a long duration requiring multiple gear racks in series, we have racks with the tooth forms properly configured at the ends. These are described as “gear racks with machined ends”. Whenever a gear rack is created, the tooth cutting process and heat treatment process can cause it to try & go out of true. We can control this with particular presses & remedial processes.