This document provides an overview of 5 common types of steering gearboxes: 1) worm and worm wheel, 2) worm and nut, 3) worm and roller, 4) recirculating ball type, and 5) rack and pinion. Each type is described in 1-2 paragraphs, outlining the key components and how rotation of the steering wheel is converted to linear motion to steer the wheels. The worm and worm wheel type is commonly used in tractors, while rack and pinion is popular for small cars due to its compact size but limited gear ratio. Recirculating ball type and worm and roller systems are used in various passenger vehicles.

1. STEERING
GEARBOXES
A Presentation by
PUSHPAJEET

2. INTRODUCTION
• To make steering of vehicle easy we require a gear reduction
arrangement, for this purpose steering gearbox came in use.

3. REQUIREMENT
• To change the rotary motion of steering wheel into
straight line motion .
• To minimize the effort of vehicle steering .
• Variation of gear ratio from 12:1 to 30:1.

4. TYPES
• Worm and worm wheel
• Worm and nut
• Worm and nut
• Recirculating ball type
• Rack and pinion

5. 1.WORM AND WORM WHEEL
STEERING GEAR

6. • There are square threads or worms on the steering rod
end which engages in a worm wheel .
• Worm wheel is connected to a drop arm .
• When driver rotates the steering wheel ,drop arm moves
forward or backward resulting in motion of stub axle.
• The arc movement of the drop arm is usually from 60 to
90 deg.
• This system is commonly used in tractors .

7. 2.WORM AND NUT STEERING
GEAR
• Steering rod end have worm.
• worm is connected with a
nut arrangement
• When worm rotates, the nut
is able to move
• Movement is along the axis
of column either up or down
.
• This move cross shaft in arc
which also move drop arm .
• This is used in steering all
wheels

8. 3.WORM AND ROLLER
STEERING GEAR
• Worm and roller gear have two teethed
roller which are fastened to the cross
shaft called roller shaft or sector shaft.
• The threads of the worm gear are
meshed with roller shaft at the end of
the steering tube.
• Dia of worm is greater at end and
reduced at center .
• When the worm shaft is turned by the
steering tube, the roller will also be
moved in an arc for rotating the roller
shaft .
• The bearings are designed to resist both
radial and end thrust.
• Used in Leyland and American
passenger car

9. 4. RECIRCULATING BALL TYPE
STEERING GEAR

10. • It consists of a worm at the end of steering rod.
• A nut is mounted on the worm with two sets of balls
in the groves of the worm , ball reduces the friction
between nut and worm .
• The teeth of nut is meshed with teeth of worm wheel
sector to which drop arm is mounted .
• By turning steering wheel , the balls in worm roll in
the grooves and cause nut to move alone the length of
worm, balls recirculates through the guide.
• Movement of nut causes the wheel sector to turn and
actuate the link rod through the drop arm resulting in
desired steering of wheels .
• Teeth on the nut are tapered to minimize the wear
• Used in TATA standard 20 vehicle

11. 5.RACK AND PINION
STEERING GEAR

12. • A pinion is mounted at the end of steering gear shaft .
• Pinion is engaged with a rack which have ball joints at
end for rise and fall of wheels .
• On revolving pinion rack moves to and fro.
• Due to this movement tie rod and stub axle also moves
and we get desired steering .
• This system is popular in small cars like Maruti 800.
• Its gear ratio is limited by the diameter of steering
wheel and pinion gear hence can’t used in heavy
vehicles