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| Illustration 1 | g00460409 |
Vibratory Pump (1) Shaft. (2) Servo housing. (3) Servo piston. (4) Barrel. (5) Housing. (6) Control valve. (7) Port plate. (8) Swashplate. (9) Spring assembly. (10) Piston (one of nine). (11) Main passage. (12) Main passage. (13) Passage for charge oil. (14) Vibratory charge pump (Internal gear pump). (15) Head. (16) Charge relief valve (one of two). | |
When the engine is running, the shaft (1) and the barrel (4) are rotating. There are nine pistons (10) in barrel (4). The port plate (7) and the swashplate (8) are held by the housing (5). The port plate (7) and the swashplate (8) do not rotate. The spring assembly (9) keeps a force on the barrel (4) in order to make a high pressure seal between the barrel (4) and the port plate (7). When barrel (4) is rotating, each piston (10) follows the angle of the swashplate. If the swashplate angle is at zero, the pistons do not move in and out of the barrel and there will be no flow. The charge oil from the internal charge pump (14) maintains oil pressure in the pump in order to keep the barrel full of oil. The charge oil lubricates the pump components. The charge oil compensates for the normal internal loss of oil due to leakage.
The position of the swashplate (8) is controlled by the control valve (6) and the servo piston (3). The control valve (6) receives an electrical signal from the vibratory on/off control and this causes the servo piston (3) to move. The control valve (6) routes the control oil in order to move the servo piston (3). The servo piston (3) controls the angle of the swashplate (8) .
Note: If the machine is equipped with the variable frequency system, the control valve receives the electrical signal by way of the variable vibration control knob. Refer to Variable Frequency Electrical Control for more information.
Oil flows from the pump to the vibratory motor and back to the main passage (12). The position of the swashplate (8) determines the direction of flow of the two main passages (11) and (12).
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| Illustration 2 | g00460410 |
Swashplate and Barrel Assembly (1) Shaft. (4) Cylinder barrel. (7) Port plate. (8) Swashplate. (9) Spring. (10) Piston. | |
The maximum position of the swashplate (8) is shown in illustration 2. As the pistons (10) follow the swashplate the pistons move in and out of the barrel (4). As the pistons (10) move out of the cylinder, oil is supplied behind the pistons. This oil is supplied under pressure from the charge circuit through passage (13). Oil is pushed ahead of the pistons (10) and this oil goes through the outlet passages of the port plate (7). Oil will exit the pump through the main loop (11). The surfaces of the port plate (7) and the barrel (4) are spherical in shape. The inlet oil and the outlet oil are sealed from each other by a metal-to-metal seal. The seal is located between the spherical faces of the port plate (7) and the cylinder barrel (4).
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| Illustration 3 | g00461598 |
Spring Assembly (4) Cylinder barrel. (9) Spring. (17) Cup. (18) Shim. | |
Spring (9) and shims (18) are held in place on the swashplate (8) by the cup (17). Spring force holds the face of the barrel (4) against the port plate (7) and the head (15) .
The length of the stroke of pistons (10) is changed when the swashplate (8) is rotated about the axis. In a neutral position, the piston stroke is ±15° and the oil delivery is zero. When the piston is at a maximum inclination, the stroke is at the maximum.