Rack and pinions are used for lifting mechanisms (vertical movement), horizontal motion, positioning mechanisms, stoppers and also to let the synchronous rotation of several shafts in general industrial machinery. On the other hand, also, they are found in steering systems to improve the direction of vehicles. The features of rack and pinion systems in steering are as follows: simple structure, high rigidity, little and lightweight, and exceptional responsiveness. With this mechanism, the pinion, mounted to the steering shaft, can be Spur Gear Rack meshed with a steering rack to transmit rotary movement laterlly (transforming it to linear motion) to ensure that you can control the wheel. Furthermore, rack and pinions are used for various other purposes, such as playthings and lateral slide gates.
As a mechanical component to transfer rotary into linear movement, gear racks are often compared to ball screws. There are pros and cons for using racks in place of ball screws. The advantages of a gear rack are its mechanical simplicity, large load carrying capacity, no limit to the length, etc. One drawback though may be the backlash. The benefits of a ball screw are 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 the pinion rotates upon a fixed axis as the gear rack moves. The previous is used widely 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 stock. If the application requires a long length requiring multiple gear racks in series, we’ve racks with the tooth forms properly configured at the ends. They are described as “gear racks with machined ends”. When a gear rack is created, the tooth cutting process and the heat treatment process can cause it to try & walk out true. We can control this with special presses & remedial processes.