Yanmar YM276 Service Manual page 617

STEERING
260-05-1
HOW THE STEERING WORKS
3367028
A -Steering Shah
B
-
BdINut
C
-
Rrirsvlning Balls
D
-
BallReWrnTvbe
E
-Sector S h h
F
-
AdjustinpScrw
G -Upper Ball Baaring
H -Lower Ball Baaring
I
-
Steering Calumn
J
-Shim
K
-
P i m a n Arm
L
-
Drag Rod
The steering gear box is designed t o multiply the operator's As the balls roll along and one b y one, come t o the end of
turning torque so that the front wheels may
be
turned
groove in the nut, they are forced through a return tube
easily and resist the transfer of road shock t o the operator.
ID). Eventually, they reenter the nut groove at the oppo-
The torque developed by the operator is multipled through
site
end,
which accounts for the name, recirculating ball
gears, then i s transmitted t o the wheel spindle assembly via
worm and nut.
linkage.
One side of t h e nut has gear teeth cut into it. The pitman
The type of gear box is recirculating ball worm and nut.
arm sector shaft (El gear teeth engage the nutteeth. When
This type use a nut ( 6 ) that rides up and down the worm
the nut travels up and down, the senor shaft i s forced t o
portion of steering shaft
(A). Balls
(CJ
ride half in the rotate.
worm and half i n the nut.
When the worm is turned,
the balls impart an axial thrust t o the ball n u t
(El.
As
the nut is prevented from turning, it will then travel u p
or down, depending on the worm direction.
SME276017183W YMZ76 and Z7SD
Kinornoro. Printed in Japan