Rack gears have their teeth cut on a flat surface. As there is no curvature on the pitch line, rack teeth cut to a basic involute tooth form have straight sides. The teeth may be cut at right angles to the direction of travel as for a spur gear, or inclined to mesh with a single helical gear. Torque can be converted to linear force by meshing a rack gear with a pinion (external spur gear or external single helical gear), when the pinion turns the rack moves in a straight line.  Conversley, if the rack is oscilating back and forth then the pinion will rotate clockwise then anitclockwise.

Such a mechanism is used in motorcars to convert the rotation of the steering wheel into the left-to-right motion of the tie rod(s) and in turn the driving wheels on the road. Other uses of the rack and pinion gear type is employed in a rack railway up steep inclines and has been incorporated into domestic stair lifts to aid disabled people to reach the upstairs of houses.

Our rack gear cutting maximum pitch is 16 Module (1.5DP) * 200mm (8 inches) face width in lengths of 1220mm (48 inches), longer available on request.

Hewitt & Topham Limited, Dyneley Road, Greenbank Business Park, Blackburn BB1 3AB United Kingdom
Tel: +44 (0) 1254 679222  Fax : +44 (0) 1254 680534  Email: sales@hewitt-topham.co.uk

Copyright Design & management by Fusion Creative Media Ltd