TOWEL 2676535 - Caterpillar

Illustration 1 g01786973
Pump unit and assembly
(1) Piston
(2) Overflow passage in piston guide
(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 Magnetic valve
(13) Filler coupling with grease 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 an electric driven pump that is controlled by an integrated control unit (17). 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 reservoir (4) if the pressure of the grease exceeds 25000 kPa (3650 psi).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 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 and Piston
Reservoir (4) is made of a transparent, durable plastic that is resistant to environmental effects such as variable temperatures. 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 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 grease5/2 Magnetic Valve
Illustration 2 g01787033
Stationary 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 magnetic valve is in the stationary position, the grease travels through primary grease line (A). The pressure