HOSE 3M9957 - Caterpillar

The 524/1724 Electric Governor System consists of the following components: 8290 Speed Control, 524/1724 Actuator and Magnetic Pickup.
8290 Speed ControlThe 8290 Speed Control measures engine speed constantly and makes necessary corrections to the engine fuel setting through the actuator connected to the fuel system.Engine speed is converted by the magnetic pickup into an AC voltage. This AC voltage is sent to the speed control where it is converted into a DC voltage that is used by the actuator to position the engine fuel rack.
524/1724 ActuatorThe 524/1724 actuator changes the electrical input from the speed control to a mechanical output that is connected to the fuel system by linkage.
Basic 524/1724 Electric Powered Governor Schematic8290 Speed Control
8290 Speed ControlThe 8290 Speed Control is used to maintain engine speed. The system monitors engine speed constantly, and makes necessary corrections to the engine fuel through the actuator connected to the fuel system.Engine speed is sensed by a magnetic pickup. As the teeth of the flywheel ring gear go through the magnetic lines of flux around the pickup, an AC voltage is made. The ratio between the frequency of this voltage and the speed of the engine is directly proportional. An electrical circuit inside the speed control converts this AC voltage into a DC voltage level.The actuator is connected to the fuel system by linkage. It changes the electrical output from the speed control to mechanical output that changes the engine fuel setting.The Rated Speed, Gain and Stability adjustments in the speed control are used to match system dynamics and desired speeds.524/1724 Actuator
Actuator SchematicThe electrical actuator has a specially designed rotor and stator which provides reliable and effective performance. The rotary design gives 35 degrees shaft rotation to a low mass, low friction fuel system. The magnetic circuit, when powered by the speed control output, applies torque in the increase fuel direction. Two preloaded internal return springs supply shaft torque in the decrease fuel direction. This creates a safety feature which returns the fuel rack to a minimum fuel position if the electric signal is lost.Magnetic Pickup
Schematic Of Magnetic Pickup
(1) Magnetic lines of flux. (2) Wire coils. (3) Gap. (4) Pole piece. (5) Flywheel ring gear.The magnetic pickup is a single pole, permanent magnet generator made of wire coils (2) around a permanent magnet pole piece. As the teeth of the flywheel ring gear (5) cut through the magnetic lines of flux (1) around the pickup, an AC voltage is generated. The frequency of this voltage is directly proportional to engine speed.This engine speed frequency signal (AC) is sent to the speed control where a conversion is made to a DC voltage level.