TM 5-2410-241-23-1
0011
IMPLEMENT AND STEERING HYDRAULIC SYSTEM CONTINUED
The steering motor is a fixed displacement bent axis motor of the piston type and is operated by oil from the
variable displacement piston pump. The steering motor can produce the same amount of output torque in either
direction.
Oil flow through the steering motor can be in either direction. A change in the direction of oil flow causes a change
in the direction of rotation for barrel (Figure 19, Item 4), for pistons (Figure 19, Item 2), and for shaft (Figure 19,
Item 10).
The parts of the motor that turn are: shaft (Figure 19, Item 10), snap ring and shims (Figure 19, Item 15), retaining
plate (Figure 19, Item 9), pistons (Figure 19, Item 2), and barrel (Figure 19, Item 4). The parts that do not turn are:
head (Figure 19, Item 7), case (Figure 19, Item 6), port plate (Figure 19, Item 5), shims (Figure 19, Item 14), ring
(Figure 19, Item 12), and cover (Figure 19, Item 16).
Oil from the pump flows to the steering motor through the steering control valve and through the counterbalance
valve. Then, oil flows through the inlet control slot in the head (Figure 19, Item 7) to the inlet control slot in the port
plate (Figure 19, Item 5).
N OT E
The direction of rotation determines the inlet and the outlet of the two slots in the head
(Figure 19, Item 7). Likewise, the direction of rotation determines the inlet and the outlet of
the two slots in the port plate (Figure 19, Item 5). Oil through the port plate flows into the
cylinders of the barrel that are over the inlet control slot of the port plate.
The cylindrical ends of pistons (Figure 19, Item 2) are held in sockets in shaft (Figure 19, Item 10) by a retaining
plate (Figure 19, Item 9). The sealed end of pistons (Figure 19, Item 2) are positioned in barrel (Figure 19, Item 4).
Barrel (Figure 19, Item 4) rotates around pivot pin (Figure 19, Item 1), which is at a fixed angle of 40 degrees to the
axis of the shaft (Figure 19, Item 10).
Because the steering motor is a bent axis type motor, seven pistons (Figure 19, Item 2) move in and out of the
cylinders as oil leaves the cylinders and as oil enters the cylinders. The motion forces the pistons to rotate around
a pivot pin (Figure 19, Item 1). Rotation of the pistons forces shaft (Figure 19, Item 10) and barrel (Figure 19,
Item 4) to rotate.
As shaft (Figure 19, Item 10), pistons (Figure 19, Item 2), and barrel (Figure 19, Item 4) continue rotation, the
pistons reach the top center (full retracted position). At the same time, the cylinder begins to overlap the outlet
control slot in the port plate (Figure 19, Item 5). The piston begins to move downward. Because the piston moves
downward, the piston pushes oil out of the cylinder, into the outlet control slot in the port plate (Figure 19, Item 5),
and through the outlet control slot in the head (Figure 19, Item 7). The same oil is then pushed to the
counterbalance valve, to the steering control valve, and to the tank.
The ball end of the pivot pin (Figure 19, Item 1) is the pivot point for the barrel (Figure 19, Item 4). Oil passage
(Figure 19, Item 8) provides lubricating oil to a drilled passage in the pivot pin (Figure 19, Item 1). The oil then flows
to the pivot pin, the pivot pin socket, and on through passages to bearings (Figure 19, Items 11 and 13). The oil
drains from the case (Figure 19, Item 6) through the port (Figure 19, Item 3).
0011-18
