A rack and pinion system can be used to transform rotary movement into linear movement and vice versa. A circular spur gear, the pinion, meshes with a spur gear which has teeth set in a straight line, the rack. Rack and pinion gears are accustomed to convert rotation into linear motion. An ideal example of this is actually the steering program 
A rack and pinion program gives the capability to transfer rotary to linear movement, with all the precision expected of a geared system.
The racks are produced from ground, hardened stainless or ground stainless and available with a selection of accuracies, pitches, and lengths, plus the facility to provide modifications such as for example flats, journals or custom ends. Hobbed stainless and brass racks are also offered. The rack pinions are simple or anti-backlash, also with a choice of accuracies, pitches, bore sizes, alternative components and coatings.
Surface rack can be used for both measurement and actuation. Generally small pitches (1 mm) suit measurement as small pinion diameter provides higher linear resolutions. The larger pitches (2 mm and 2.5 mm) enable an increased load capacity. For most applications the rack can be used for both the opinions and the actuation; however in very specific applications it is advisable to us a non-drive section of the rack for opinions, alternatively a separate rack can be used. Hobbed rack are more suitable for light actuation applications where cost is an integral consideration.
You can expect three types of rack – rectangular, solid round and tubular rack. Rectangular rack are utilized when the application needs the rack to be stationary and the rack pinion provides the element of motion. Our rectangular racks are used in combination with a Spur Gear Rack electric motor, slide and carriage for instance in the printing sector for the actuation of paper reducing knives in a printing press. Round rack are a more flexible alternative, with regard to mounting, utilized for example in XY phases. The tubular racks enable the passage of liquids, fibre-optics, gasses etc, producing them ideal for medical and scientific applications, such as for example laboratory automation pick and place mechanisms.
Round racks are well suited for linear actuators in accurate automation applications . Tubular racks are specially useful for medical and scientific applications, where in fact the hollow shaft permits the passage of liquids, fibre optics and gases.