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 in general industrial machinery. However, they are also used in steering systems to improve the direction of cars. 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, mounted to the steering shaft, can be meshed with a steering rack to transmit rotary motion laterlly (converting it to linear movement) to ensure that you can control the wheel. In addition, rack and pinions are utilized for many other purposes, such as playthings 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 benefits and drawbacks for using racks in place of ball screws. The advantages of a equipment rack are its mechanical simplicity, large load carrying capacity, and no limit to the distance, etc. One disadvantage though is the backlash. The advantages of a ball screw will be 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 the pinion rotates upon a fixed axis while the gear rack moves. The former is used broadly in conveying systems as the latter can be used in extrusion systems and lifting/lowering applications.
To provide many variations of rack and pinion, KHK has many types of gear racks in share. If the application takes a long size requiring multiple gear racks in Spur Gear Rack series, we have racks with the tooth forms properly configured at the ends. They are described as “equipment racks with machined ends”. Whenever a equipment rack is created, the tooth cutting process and the heat treatment process could cause it to try & walk out true. We can control this with special presses & remedial processes.