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| Illustration 1 | g01420194 |
Vibratory Hydraulic System (Fixed Frequency Off) (1) Vibratory motor assembly (2) Vibratory motor (3) Flushing relief valve (4) Flushing spool (5) Amplitude control valve (6) High amplitude combination valve (7) Relief valve (8) Makeup valve (9) Vibratory pump (10) Thermal bypass return manifold (11) Relief valve (12) Makeup valve (13) Charge relief valve (14) Oil cooler (15) Tank (16) Relief valve (17) Thermal bypass valve (18) Low amplitude combination valve | |
This schematic shows the vibratory hydraulic system when the vibratory control switch is in the OFF position. The steering pump provides charge flow when the engine is running. Steering oil is directed to the front charge filter. Filtered charge oil flows into port "G" of the vibratory pump. Inside the vibratory pump, charge oil flows to the makeup and relief valves, to the amplitude control valve, and to the charge relief valve.
With the amplitude control switch in the OFF position, the direction control valve is in the center position. In this case, both sides of the pump servo are open to the tank. The swashplate in the vibratory pump remains at the minimum angle, and the vibratory motor does not rotate.
Charge pressure acts on the charge relief valve. When charge pressure is greater than 2600 ± 250 kPa (377 ± 36 psi), the oil pressure overcomes the spring force, and the charge relief valve opens. An orifice limits the amount of flow through the charge relief valve. The pressure setting of the charge relief valve in the vibratory pump is less than the pressure setting of the charge relief valve in the drum pump. This fact ensures that oil is sent through the case drain of the vibratory pump under normal operating conditions. Since the orifice limits the oil flow through the charge relief valve on the vibratory pump, the charge relief valve on the drum pump controls charge pressure.
Charge pressure acts against the makeup valves. If the pressure in either the high amplitude loop or the low amplitude loop falls below charge pressure, the makeup valve opens, and charge oil flows into the loop.
Since the vibratory system is not operating, the flushing valve in the vibratory motor remains in the center position.
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| Illustration 2 | g01420204 |
Vibratory Hydraulic System (Fixed Frequency, High Amplitude) (1) Vibratory motor assembly (2) Vibratory motor (3) Flushing relief valve (4) Flushing spool (5) Amplitude control valve (6) High amplitude combination valve (7) Relief valve (8) Makeup valve (9) Vibratory pump (10) Thermal bypass return manifold (11) Relief valve (12) Makeup valve (13) Charge relief valve (14) Oil cooler (15) Tank (16) Relief valve (17) Thermal bypass valve (18) Low amplitude combination valve | |
This schematic shows the vibratory hydraulic system when the control switch is in the ON position, and the vibratory amplitude control switch is in the HIGH AMPLITUDE position.
In this condition, the high amplitude solenoid is energized, and the right envelope of the direction control valve is active. Charge oil enters the high amplitude servo cavity of the pump. The pressure in the cavity overcomes the spring force. The pump servo moves, and the angle of the swashplate changes.
Supply oil from the high amplitude side of the vibratory pump flows to the high amplitude side of the vibratory motor. The supply oil causes the motor to rotate. After turning the motor, reduced pressure oil returns to the low amplitude side of the vibratory pump. The oil that returns completes the circuit.
Pump supply oil also flows to the high amplitude combination valve and to the flushing valve. As long as the pressure that is in the high amplitude circuit is greater than charge pressure and less than the relief pressure, the makeup valve that is in the high amplitude circuit will remain seated. In this case, the relief valve remains closed.
When pressure in the low amplitude loop is below charge pressure, the makeup valve is open. This situation allows charge oil to flow into the low amplitude loop. If the pressure in the low amplitude loop rises above charge pressure, the makeup valve closes.
Oil in the high amplitude circuit acts against one side of the flushing valve, and oil in the low amplitude circuit acts against the other side. The difference in pressure moves the flushing spool, and oil in the low amplitude circuit flows across the spool to the relief section of the flushing valve. Whenever the pressure in the low amplitude circuit is greater than 1600 kPa (232 psi), the flushing relief valve opens. This will allow oil in the low amplitude circuit to flow through the vibratory motor case drain line.
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| Illustration 3 | g01420235 |
Vibratory Hydraulic System (Fixed Frequency, Low Amplitude) (1) Vibratory motor assembly (2) Vibratory motor (3) Flushing relief valve (4) Flushing spool (5) Amplitude control valve (6) High amplitude combination valve (7) Relief valve (8) Makeup valve (9) Vibratory pump (10) Thermal bypass return manifold (11) Relief valve (12) Makeup valve (13) Charge relief valve (14) Oil cooler (15) Tank (16) Relief valve (17) Thermal bypass valve (18) Low amplitude combination valve | |
This schematic shows the vibratory hydraulic system when the vibratory system control switch is in the ON position, and the vibratory amplitude control switch is in the LOW AMPLITUDE position.
In this condition, the low amplitude solenoid is energized, and the left envelope of the direction control valve is active. Charge oil enters the low amplitude servo cavity of the pump. The pressure in the cavity overcomes the spring force. The pump servo moves, and the angle of the swashplate changes.
Supply oil from the low amplitude side of the vibratory pump flows to the low amplitude side of the vibratory motor. The supply oil causes the motor to rotate. After turning the motor, reduced pressure oil returns to the high amplitude side of the vibratory pump. The oil that returns completes the circuit.
Pump supply oil also flows to the low amplitude combination valve and to the flushing valve. As long as the pressure in the low amplitude circuit is greater than charge pressure and less than relief pressure, the makeup valve in the low amplitude circuit remains seated. In this case, the relief valve remains closed.
When pressure in the high amplitude loop is below charge pressure, the makeup valve is open. This situation allows charge oil to flow into the high amplitude loop. If the pressure in the high amplitude loop rises above charge pressure, the makeup valve closes.
Oil in the low amplitude circuit acts against one side of the flushing valve, and oil in the high amplitude circuit acts against the other side. The difference in pressure moves the flushing spool, and oil in the high amplitude circuit flows across the spool to the relief section of the flushing valve. Whenever the pressure in the high amplitude circuit is greater than 1600 kPa (232 psi), the flushing relief valve opens. This allows oil in the high amplitude circuit to flow through the vibratory motor case drain line.
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| Illustration 4 | g01420260 |
Vibratory Hydraulic System (Variable Frequency Off) (1) Vibratory motor assembly (2) Vibratory motor (3) Flushing relief valve (4) Flushing spool (5) Amplitude control valve (6) High amplitude combination valve (7) Relief valve (8) Makeup valve (9) Vibratory pump (10) Thermal bypass return manifold (11) Relief valve (12) Makeup valve (13) Charge relief valve (14) Oil cooler (15) Tank (16) Relief valve (17) Thermal bypass valve (18) Low amplitude combination valve | |
The variable frequency vibratory system is similar to the fixed frequency vibratory system. However, in the variable frequency system the control solenoids are proportional. The function of the control solenoids is also different between the two systems. In the variable vibratory system, solenoid "A" operates the system in low amplitude, and solenoid "B" operates the system in high amplitude.