| |
| Illustration 1 | g06121895 |
|
Under Cab (1) Vibratory pump | |
Vibratory pump (1) is located under the operator platform. For open platform machines, the side panels under the operator platform must be removed to provide access to this pump.
Vibratory pump (1) is the second in a series of two pumps which are driven by the engine flywheel. The propulsion pump is driven by the engine, and the vibratory pump is splined to the propulsion pump. The vibratory pump is an axial piston pump with a variable displacement.
| |
| Illustration 2 | g06131377 |
|
Bottom of Vibratory Pump (2) Frequency adjustment screw (3) Solenoid "B" (4) Solenoid "A" (5) Combination valve for port "B" (6) Port"MB" (7) Port"MA" (8) Combination valve for port "A" (9) Charge relief valve | |
The vibratory pump is controlled by a single solenoid. On the combination compactor machines, solenoid"A" controls the operation of the vibratory pump. Pump control solenoid"A" is an on/off solenoid.
Solenoid"A" (4) is located on the top of the pump. Solenoid"A" is energized when the vibratory system is operating while the machine is traveling in the forward direction. When this solenoid is energized, supply pressure can be measured at port"MA" (7), and return circuit pressure can be measured at port"MB" (6).
Solenoid"B" (3) is located on the bottom of the pump. Solenoid"B" is energized when the vibratory system is operating while the machine is traveling in the reverse direction. When this solenoid is energized, supply pressure can be measured at port"MB" (6), and return circuit pressure can be measured at port"MA" (7).
The vibratory pump is equipped with two frequency adjustment screws. The frequency adjustment screws are displacement limiters. The frequency adjustment screw for high amplitude (not shown) is located on the top face of the pump. This adjustment screw is not used for this machine.
Frequency adjustment screw (2) for low amplitude is located on the bottom face of the pump. This adjustment screw limits the maximum position of the swashplate when the amplitude status is set to low amplitude.
The pump housing contains two combination valves, one for port"B" (5) and one for port"A" (8). Each combination valve contains a high-pressure relief valve and a makeup valve. The relief function of each valve limits maximum system pressure at the corresponding outlet port. Both of these valves are set to
The pump is also equipped with charge relief valve (9). This valve is located on the bottom face of the pump. The charge relief valve in the vibratory pump and the charge relief valve in the propulsion pump work in conjunction. These valves maintain charge pressure and also regulate case drain flow through the respective pump.
| |
| Illustration 3 | g06131380 |
|
Vibratory Pump Cross Section (11) Servo piston (12) Drive shaft (13) Swashplate (14) Slipper pad (15) Piston (16) Barrel assembly (17) Port plate | |
Engine rotation turns pump drive shaft (12). This action rotates barrel assembly (16). Pistons (15) in the vibratory pump rotate with the barrel assembly. Piston slipper pads (14) allow the pistons to follow the angle of swashplate (13). The pump only generates flow when the swashplate is not at minimum angle.
When the vibratory system is not operating, both sides of servo piston (11) are open to the case drain. The servo piston springs center the servo piston, and swashplate (13) remains at minimum angle. With the swashplate at minimum angle, pistons (15) do not move in and out of barrel assembly (16) as the barrel rotates. Therefore, the pump does not generate oil flow.