BOLT 0992789 - Caterpillar

General Information
The fan system is composed of two groups. The groups are the hub assembly with blades and the control system.System Operation
Use the following illustration for terminology and component identification. The appearance of your fan may vary.
Illustration 1 g00888300
Typical Hydraulic Actuated Fan
(1) Hub Assembly
(2) Blade Assembly
(3) Pulley
(4) Hydraulic Connector
(5) Mounting Bracket
(6) Identification Tag
Illustration 2 g00888301
(3) Pulley
(4) Hydraulic Connectors
(5) Mounting Bracket
(7) Piston
(8) Rod Shaft
(9) Hex Through Shaft
(10) Shifter Block Assembly
(11) Pivot Block
(12) Bolt
(13) Bearing
(14) Front Shifter Block Plate
(15) Rear Shifter Block Plate
(16) Collar
(17) Blade Mounting Shaft The ECM applies power through an electrical wire to one of the solenoids on the valve. Fluid from the valve travels through the hydraulic lines to hydraulic connectors (4). Fluid pressure pushes a double acting piston (7) that is connected to rod shaft (8). Rod shaft (8) is threaded to hex through shaft (9). Hex through shaft (9) is connected to the shifter block assembly (10) with bolt (12). The shifter block assembly consists of bearings (13), front shifter block plate (14) and rear shifter block plate (15). Each blade mounting shaft (17) has a collar (16) and a pin. The pin is offset from the center of the shaft of the blade. The other end of the pin sits in pivot block (11). The pivot block fits between the two shifter block plates of the shifter block assembly.The ECM determines that a purge is required. The ECM sends a signal to the solenoid valve. The solenoid valve sends hydraulic fluid through the hydraulic connectors on the hub assembly. This causes piston (7) to move. The piston moves rod shaft (8), hex through shaft (9), and the shifter block assembly (10). As the shifter block assembly moves pivot block (11) and the pin, collar (16) rotates the blade mounting shaft (17). The blades are attached to the blade mounting shaft. This moves the blades in order to make the air flow in the opposite direction for the specified duration of the purge.