BENDIX BW1837 manual Description, Operation

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®

SD-15-4111

Bendix® ET- S& ET-S2Suspended Electronic Treadle

TREADLE

POTENTIOMETER

MOUNTING

PLATE

ACTUATOR BODY

MOUNTING

TREADLE PIVOT PIN

PLATE

ACTUATOR BASE

CONNECTOR

TREADLE

 

 

TREADLE

POTENTIOMETER

MOUNTING

 

 

 

ET-STREADLE

PLATE

ET-S2TREADLE

 

FIGURE 1 - ET-SAND ET-S2ELECTRONIC TREADLES

DESCRIPTION

The ET-Sand ET-S2treadles are engine compartment bulkhead mounted electronic treadles. On electronically controlled diesel engines, the electronic treadle fulfills the same function as a conventional mechanical throttle. However, rather than transmitting a mechanical force to the engine governor, the electronic treadle controls engine speed by supplying a variable electrical voltage to the engine’s electronic controller.

The main components of the ET-Sand ET-S2treadles are: a mounting plate, suspended treadle, potentiometer (variable resistor), actuator body and base. The selected potentiometer, chosen for a specific engine application, provides the electrical link to the engine control system.

OPERATION

The electronic treadles provide smooth, graduated throttle control through the function of its potentiometer (variable resistor). The drive shaft of the cam follower assembly transfers any movement of the treadle to the potentiometer.

 

DETROIT

CATERPILLAR

CUMMINS

 

DIESEL

 

 

 

 

 

 

CLOSED

 

 

 

THROTTLE

7 - 18%

10 - 20%

5 - 17%

IDLE (OPEN)

 

 

 

 

 

 

 

OPEN

 

 

 

THROTTLE

74 - 90%

75 - 90%

70 - 81%

(FULL)

 

 

 

FIGURE 2 - OUTPUT VOLTAGE, AS A PERCENTAGE OF

SUPPLY VOLTAGE

8V

 

 

MAX

CATERPILLAR

 

RPM

 

 

5V

 

 

 

ET-S

 

 

ENGINE

TREADLE

 

 

OUTPUT

CUMMINS

DETROIT

VOLTAGE

 

DIESEL

 

 

 

 

0V

 

 

IDLE

CLOSED THROTTLE

 

OPEN THROTTLE

(OPEN)

 

(FULL)

FIGURE 3 - OUTPUT VOLTAGE

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Contents Operation DescriptionDisassembly Preventive MaintenanceGeneral ET-S& ET-S2TREADLE RemovalTreadle Removal ET-STreadle Cleaning and InspectionET-S2Treadle Potentiometer RemovalPosition Sensor AssemblyOpen Throttle full Range 70-81% Test 3 Perform the following Operational Test beforeTreadle Installation ET-STreadle ET-S& ET-S2TREADLE Installation