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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.
Main Relief Valve
The main relief valve (1) is a cartridge type valve. The main relief valve provides two functions for the vibratory circuit.
- The main relief valve limits the pressure.
- The main relief valve acts as a makeup valve for the main loop circuit.
The maximum pressure of each loop line of the closed circuit is limited by the main relief valves to 35000 kPa (5076 psi). The pressure is above the low pressure side of the main loop circuit.
Main Relief Function
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| Illustration 4 | g00459561 |
Relief Valve Cross Section (1) Main relief valve. (2) Locking cap. (3) Conical spring. (4) Collar. (5) Spindle. (6) Spring. (7) Collar. | |
Oil from the vibratory pump flows through the relief valve (1) at the passages (A). High pressure oil enters passage (A) and the oil acts on the collars (4) and (7). The force of spring (6) keeps the valve closed until the oil pressure in the high pressure side of the main loop circuit reaches relief pressure. After the relief pressure is reached, the pressure moves the spindle (5) downward while the pressure compresses the spring (6). The relief oil flows from the high pressure side to the low pressure side of the main loop. The oil flows through the gap between the spindle (5) and the collar (7). The arrows show this flow in illustration 4. High pressure oil enters the low pressure side of the main loop circuit until the force of the spring (6) seats the spindle (5) and the collar (7) .
Make Up Function
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| Illustration 5 | g00459758 |
Relief Valve Cross Section (2) Locking cap. (3) Conical spring. (4) Collar. (5) Spindle. (6) Spring. (7) Collar. | |
Oil from the vibratory pump flows through the relief valve (1) at the passages (A). The force of the spring (3) and the oil pressure in passage (A) keep the collar (7) closed. Charge pressure acts on the bottom of collar (7) and the spindle (5). When the oil pressure in passage (A) drops below the charge pressure, collar (7) and the spindle (5) move upward compressing the spring (3) .
The charge oil flows through the gap. The closed loop circuit will be replenished with the makeup oil. The arrows show this flow in illustration 5. Charge oil continues to replenish the low pressure side of the circuit with the make up oil until the pressure in passage (A) becomes greater than the charge pressure.
Solenoid Valve
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| Illustration 6 | g00460011 |
Servo (1) Springs. (2) Solenoid. (3) Valve spool. (4) Solenoid. | |
The control valve is attached to the vibratory pump. The valve is a three-position solenoid. The valve is a four-way directional control valve. The solenoid control valve directs oil to the servo circuit of the vibratory pump.
When current is supplied to either solenoid (2) or (4), the solenoid moves the valve spool (3). The controlled oil passes across the valve spool (3). The oil exits the passage to the hydraulic servo.
When the vibratory circuit is not activated, current flow to the solenoid (2) or (4) is interrupted. The force of the springs (1) moves the valve spool (3) to the center position. The force of each spring (1) is identical. The springs (1) balance each other. The springs also maintain the center position of the valve spool (3) .
Servo Piston Assembly
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| Illustration 7 | g00565422 |
Section View Of The Vibratory Pump (1) Shaft. (2) Bearing. (3) Pump housing. (4) Swashplate. (5) Joint pin. (6) Servo housing. (7) Servo piston. (8) Barrel. (9) Solenoid valve. | |
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| Illustration 8 | g00565446 |
Section View Of The Servo Piston (6) Servo housing. (7) Servo piston. (10) Springs (centering). (11) Piston rod. (12) Stroke limiter screw. (13) Locknut. | |
The servo control assembly controls the swashplate angle (4) of the vibratory pump. The servo housing (6) is an integral part of the vibratory pump. The servo housing (6) contains the servo piston (7) .
The charge circuit supplies control oil to the control valve (9) on the vibratory pump. The control valve (9) regulates the servo piston (7) by directing the oil flow which enters the servo housing (6). The control valve (9) also acts on the servo piston (7). Linear movement of the servo piston (7) mechanically controls the rotational movement of the swashplate (4) with the joint pin (5). When the servo piston (7) moves, the angle of the swashplate (4) changes in the pump.
The flow of the pump output is zero when the swashplate angle is zero. The swashplate angle is zero when the servo piston (7) is in the center position. The servo piston (7) will return to the center position when the control valve (9) is not energized. The servo piston (7) is mechanically centered by the springs (10). The center position of the servo piston (7) can be adjusted by loosening the locknut (13) and turning the piston rod (11) .
The pump flow is controlled by the servo piston (7). The maximum pump output is determined when the swashplate (4) is at the maximum angle. The maximum swashplate angle is controlled by limiting the travel of the servo piston (7). Adjust the stroke limiter screw (12) in order to control the travel of the servo piston. There are two stroke limiter screws. The screws determine the direction of travel for the servo piston (7). The stroke limiter screws (12) are located on each end of the servo housing (6). The stroke limiter screws (12) are used when you set the VPM in high amplitude and in low amplitude.
Variable Frequency Electrical Control (If Equipped)
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| Illustration 9 | g00610238 |
Control Console (1) Vibratory ON/OFF control. (2) Vibratory amplitude control. (3) Variable vibration control knob. | |
The variable vibratory system is an option. The functions of the vibratory ON/OFF control (1) and the vibratory amplitude control (2) are identical to the dual amplitude system.
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| Illustration 10 | g00451360 |
Control Console (4) Variable frequency controller. | |
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| Illustration 11 | g00565350 |
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| Illustration 12 | g00565350 |
Variable Frequency Controller Potentiometers (4) Variable frequency controller. (5) Ramp time potentiometer. (6) " P5" Low amplitude-minimum frequency potentiometer. (7) Ramp time potentiometer. (8) " P6" High amplitude-minimum frequency potentiometer. (9) " P3" Low amplitude-maximum frequency potentiometer. (10) " P4" High amplitude-maximum frequency potentiometer. | |
The main differences between the variable frequency system and the dual amplitude system are the variable frequency controller (4) and the rheostat.
Variable vibration control knob (3) is connected to the rheostat. The rheostat controls the hydraulic system for the drum vibration. The rheostat will vary the amperage to the control valve on the vibratory pump.
"P1" and "P2" ramp time potentiometers (5) and (7) control the amount of time so that the pump control can receive the correct amount of amperage. The ramp time potentiometers allow the amperage to increase from zero to the maximum amperage in two seconds.
Place the vibratory amplitude control (2) in the LOW AMPLITUDE position and turn the variable vibration control knob (3) to a full counterclockwise position. The position enables the "P5" potentiometer (6) to control the amperage to the pump control. The position enables the "P5" potentiometer (6) to maintain the lower limit of vibration per minute (VPM) at 1400 ± 50 VPM.
The nominal amperage for the "P5" low amplitude-minimum frequency potentiometer (6) is 450 mA.
Place the vibratory amplitude control (2) in the HIGH AMPLITUDE position and turn the variable vibration control knob (3) to a full counterclockwise position. The position enables the "P6" potentiometer (8) to control the amperage to the pump control. The position enables the "P6" potentiometer (8) to maintain the lower limit of vibration per minute (VPM) at 1400 ± 50 VPM.
The nominal amperage for the "P6" high amplitude-minimum frequency potentiometer (8) is 450 mA.
Place the vibratory amplitude control (2) in the LOW AMPLITUDE position and turn the variable vibration control knob (3) to a full clockwise position. The position enables the "P3" potentiometer (9) to control the amperage to the pump control. The position enables the "P3" potentiometer (9) to maintain the upper limit of vibration per minute (VPM) at 1965 ± 50 VPM.
The nominal amperage for the "P3" low amplitude-maximum frequency potentiometer (9) is 520 mA.
Place the vibratory amplitude control (2) in the HIGH AMPLITUDE position and turn the variable vibration control knob (3) to a full clockwise position. The position enables the "P4" potentiometer (10) to control the amperage to the pump control. The position enables the "P4" potentiometer (10) to maintain the upper limit of vibration per minute (VPM) at 1965 ± 50 VPM.
The nominal amperage for the "P4" high amplitude-maximum frequency potentiometer (10) is 520 mA.