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| Illustration 1 | g01070927 |
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Pump unit and assembly (1) Piston (2) Overflow passage (3) Piston guide (4) Grease reservoir (5) Stirring gear (6) Minimum level switch (7) Electric connector (8) Cam (9) Overflow passage (right side of pump) (10) Relief valve (11) Cylinder and plunger (12) 5/2 Solenoid valve (13) Coupling with lubrication filter (14) Coupling for primary grease line (A) (15) Test button (16) Electro-mechanical motor (17) Control unit (18) Mechanical transmission (19) Coupling for primary grease line (B) | |
The lubrication pump is controlled by an electrically driven pump plunger. The pump plunger is made up of three radially placed, fixed cylinders (11). Electro-mechanical motor (16) drives the axle through the mechanical drive. Cam (8) moves the three plungers in order to pump the grease to the distribution blocks through the primary grease line. The axle drives stirring gear (5) which pushes the grease downward.
Relief valve (10) sends the grease back to grease reservoir (4) if the pressure of the grease exceeds
Note: If there is a leak in the line, the pump will be unable to create the required pump pressure. If this occurs, the pump needs to be shut off in order to prevent the contents of the grease reservoir from being pumped into the environment. The control unit will stop the pump if the required grease pressure has not been reached in 10 successive attempts. The number of attempts can be adjusted from 1 attempt to 25 attempts.
Grease reservoir (4) is made of a transparent, durable plastic that is resistant to environmental effects such as variable temperatures. Grease reservoir (4) has a mark along the side walls in order to indicate the maximum grease level. A warning signal inside the cab alerts the operator when the grease level is at the minimum level through minimum level switch (6).
Piston (1) follows the level of the grease. When the grease level falls, piston (1) also falls due to the effects of a spring. The piston is pressed tightly against the sides of the grease reservoir which locks out air and condensation. The airtight fit causes the piston to scrape the sidewalls as the piston falls. This allows the operator to get an accurate reading of the grease level. This also ensures that all of the grease is used. The elimination of air in the grease prevents the following:
- Oxidation of the grease
- Mixing of the grease with the water of condensation
- Contamination of the grease
- Degradation of the grease
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| Illustration 2 | g01070948 |
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De-energized position (A) Primary grease line (A) (B) Primary grease line B (P) Line from pump (Ra) Return line (A) to grease reservoir (Rb) Return line B to grease reservoir | |
When the solenoid valve is in the de-energized position, the grease travels through primary grease line (A). The pressure in primary grease line (B) will decrease and grease will return to the grease reservoir through return line (Rb).
When the solenoid valve is energized by the control unit, lubricant supply line (P) is connected to line (B), and line (A) is connected to return line (Ra). Therefore, grease will travel through primary grease line (B). The pressure in primary grease line (A) will decrease and grease will return to the grease reservoir through return line (Ra).
Minimum Level Switch for the Grease
Minimum level switch (6) maintains the level of the grease in the grease reservoir. When the grease reaches the minimum level, the level switch will send a signal to the control unit. At the beginning of each following lubrication cycle, the signal lamp will flash in order to alert the operator that the grease reservoir must be refilled.
The signal lamp uses flash codes in order to alert the operator of any malfunctions. The flash codes are emitted by the signal lamp.
Reference: For additional information on the meaning of the flash code, refer to Testing and Adjusting, "Automatic Lubrication System Troubleshooting".
Relief valve (10) is mounted in the grease line between the pump and the diverter valves. The relief valve will redirect the grease to the grease reservoir when the grease pressure exceeds