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 change the direction of vehicles. The features of rack and pinion systems in steering are as follows: simple structure, high rigidity, little and lightweight, and superb responsiveness. With this mechanism, the pinion, installed to the steering shaft, can be meshed with a steering rack to transmit rotary motion laterlly (transforming it to linear motion) to ensure that you can control the wheel. In addition, rack and pinions are utilized for various other purposes, such as toys and lateral slide gates.
As a mechanical component to transfer rotary into linear movement, gear racks are often in comparison to ball screws. There are pros and cons for using racks instead of ball screws. The advantages of a gear rack are its mechanical simplicity, huge load carrying capacity, no limit to the length, etc. One drawback though may be the backlash. The advantages of a ball screw are the high precision and lower backlash while its shortcomings are the limit in length due to deflection.
There are applications where the gear rack is stationary, while the pinion traverses and others where in fact the pinion rotates upon a fixed axis while the gear rack moves. The former 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 various kinds of gear racks in stock. If the application takes a long length requiring multiple equipment racks in series, we’ve racks with the tooth forms correctly 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 & walk out true. We can control this with particular presses & remedial Spur Gear Rack processes.