Rack and pinions are used for lifting Spur Gear Rack mechanisms (vertical movement), horizontal motion, 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 steering systems to change the direction of vehicles. The characteristics of rack and pinion systems in steering are the following: simple structure, high rigidity, little and lightweight, and exceptional responsiveness. With this system, the pinion, installed to the steering shaft, is definitely 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 various other purposes, such as toys and lateral slide gates.

As a mechanical element to transfer rotary into linear motion, gear racks tend to be compared to ball screws. There are advantages and disadvantages for using racks instead of ball screws. The advantages of a equipment rack are its mechanical simplicity, large load carrying capacity, and no limit to the length, etc. One drawback though is the backlash. The advantages of a ball screw are the high precision and lower backlash while its shortcomings are the limit in size due to deflection.

There are applications where in fact the gear rack is stationary, as the pinion traverses and others where in fact 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 used in extrusion systems and lifting/lowering applications.

To provide many variants of rack and pinion, KHK has many types of gear racks in stock. If the application takes a long size requiring multiple equipment racks in series, we have racks with the tooth forms properly configured at the ends. They are described as “equipment racks with machined ends”. Whenever a gear rack is produced, the tooth cutting procedure and heat treatment process could cause it to try & go out of true. We can control this with particular presses & remedial processes.