Vibratory Pump (Swashplate at maximum angle)(Typical Example).
(6) Port plate. (8) Cylinder. (9) Housing. (10) Splines. (11) Spring. (12) Closed circuit loop line port. (13) Retaining ring. (14) Retainer. (15) Closed
circuit loop line port.
When the swashplate is moved to the maximum angle, the
pistons move in and out of the cylinder at the maximum stroke.
As the piston moves out of the cylinder, oil from the low
pressure loop line is supplied behind it. When the piston
moves back into the cylinder the oil that is pushed ahead of the
piston goes through port plate (6) and into closed circuit loop
line port (12).
Closed circuit loop line port (12) is shown as a
high pressure loop line, and closed circuit loop
line port (15) is shown as a low pressure loop line
in the illustration. Moving the swashplate over-
center in the opposite direction causes a change
in the direction of flow. Closed circuit loop line
port (12) becomes low pressure and closed circuit
loop line port (15) becomes high pressure.
Port plate (6) and the end of cylinder (8) are high pressure,
metal to metal, seal surfaces and are precision machined parts
that must be protected from damage. Retainer (14) is against
the edge of splines (10). Retaining ring (13) is in a groove in
the bore of the cylinder. The force of spring (11) between the
retainer and retaining ring (13) holds the cylinder tight against
the port plate and the port plate against housing (9).
The swashplate has a pin attached that is moved by the servo
piston assembly. The servo piston assembly controls both the
direction and amount of swashplate angle.