A rack and Spur Gear Rack pinion system is utilized to transform rotary movement into linear movement and vice versa. A circular spur equipment, the pinion, meshes with a spur gear which has teeth occur a straight line, the rack. Rack and pinion gears are used to convert rotation into linear movement. A perfect example of this is actually the steering program on many cars. The tyre rotates a gear which engages the rack. As the apparatus turns, it slides the rack either to the right or left, depending on which way you turn the wheel.
A rack and pinion program gives the ability to transfer rotary to linear motion, with all the accuracy expected of a geared system.
The racks are manufactured from ground, hardened stainless or ground stainless steel and available with a choice of accuracies, pitches, and 
lengths, in addition to the facility to supply modifications such as flats, journals or custom ends. Hobbed stainless steel and brass racks are also available. The rack pinions are ordinary or anti-backlash, also with a choice of accuracies, pitches, bore sizes, alternative components and coatings.
Ground rack can be used for both measurement and actuation. In general small pitches (1 mm) fit measurement as the smaller pinion diameter gives higher linear resolutions. The larger pitches (2 mm and 2.5 mm) allow for an increased load capacity. For some applications the rack can be used for both the feedback and the actuation; however in very precise applications it is advisable to us a non-drive section of the rack for opinions, alternatively another rack can be used. Hobbed rack are more suited to light actuation applications where price is an integral consideration.
We offer three types of rack - rectangular, solid round and tubular rack. Rectangular rack are utilized when the application requires the rack to become stationary and the rack pinion provides the element of motion. Our rectangular racks are used in combination with a engine, slide and carriage for instance in the printing market for the actuation of paper reducing knives in a printing press. Circular rack are a more versatile alternative, with regard to mounting, used for instance in XY stages. The tubular racks enable the passage of liquids, fibre-optics, gasses etc, making them well suited for medical and scientific applications, such as laboratory automation choose and place mechanisms.
Round racks are perfect for linear actuators in accurate automation applications . Tubular racks are especially useful for medical and scientific applications, where the hollow shaft permits the passage of fluids, fibre optics and gases.