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Figure 2-3. OPERATION OF THE MASTER SPEED INDICATOR Sub Log Home Page
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Figure 2-3. OPERATION OF THE MASTER SPEED INDICATOR
Operation of the Master Speed Indicator
1 MILES TRAVELED IS TRANSMITTED BY THE ROTARY DISTANCE TRANSMITTER TO THE RECIEVER-RECEIVER TURNS AT A FAST OR SLOW RATE DEPENDENT ON THE SPEED AT WHICH THE MILES ARE BEING TRAVELED.
2 UPPER DIFFERENTIAL GEAR TURNED BY RECIEVER
3 DIFFERNENTIAL SPIDER GEAR DRIVEN BY UPPER DIFFERENTIAL GEAR, RIDES AROUND ON STATIONARY LOWER DIFFERENTIAL GEAR
4 LOWER CONTACT ASSEMBLY IS DRIVEN BY THE DIFFERENTIAL SPIDER, CLOSING CONTACT TO THE LEAD SCREW DRIVING MOTOR THROUGH THE UPPER CONTACT.
5 LEAD SCREW DRIVING MOTOR TURNS LEAD SCREW. LEAD SCREW RAISES YOKE.
6 LIMIT SWITCH IS RELEASE STARTING CONSTANT SPEED MOTOR AND DISK (100 RPM).
7 WHILE CONTACT IS MAINTAINED TO LEAD SCREW MOTOR, YOKE CONTINUES TO RISE.
8 ROLLER AND PINION ARE FRICTION DRIVEN BY THE CONSTANT SPEED DISK AND AS THE YOKE CONTINUES TO RAISE THE ROLLER AND PINION, THEIR SPEED WILL INCREASE AS THEY APPROACH THE OUSTSIDE OF THE DISK.
9 LOWER DIFFERENTIAL GEAR IS DRIVEN BY THE ROLLER AN PINION AT A CONSTANTLY INCREASING SPEED-NOT AS FAST AS THE UPPER DIFFERENTIAL GEAR AND IN THE OPPOSITE DIRECTION.
10 THE SPIDER CONTINUES TO ROTATE IN THE SAME DIRECTION AS THE FASTER MOVING UPPER DIFFERENTIAL GEAR.  THE SPEED OF ROTATION WILL DECREASE AS THE UPPER AND LOWER DIFFERENTIAL GEARS APPROACH THE SAME SPEED.
11 NOTE... THE SPEED POINTER IS TURNED BY THE LEAD SCREW THROUGH A SELF-SYNCHRONOUS TRANSMITTER, THE POSTION OF THE SPEED POINTER ON THE DIAL IS RELAYED TO THE REPEATERS.
12 THE UPPER CONTACT ASSEMBLY IS DRIVEN FROM THE TOP OF THE LEAD SCREW AT THE SLOWER SPEED THAN THE LOWER CONTACT ASSEMBLY.  BECAUSE THE LOWER CONTACT IS BEING DRIVEN FASTER THAN THE UPPER CONTACT, A FRICTION DRIVE ON THE UPPER CONTACT ALLOWS IT TO BE PUSHED BEYOND ITS DRIVEN SPEED BY THE FASTER MOVING LOWER CONTACT, MAINTAINING A FIRM CONNECTION TO THE LEAD SCREW MOTOR.
13. THE LOWER DIFFERENTIAL GEAR IS APPROACHING THE SAME SPEED AS THE UPPER DIFFERENTIAL GEAR CAUSING THE SPIDER AND LOWER CONTACT TO DECREASE IN SPEED. WHEN THE SPIDER AND LOWER CONTACT HAS REACHED A SPEED BELOW THAT OF THE UPPER CONTACT, THE UPPER CONTACT MOVES AWAY FROM THE LOWER CONTACT BREAKING THE CONNECTION TO THE LEAD SCREW MOTOR AND STOPPING ROTATION OF THE UPPER CONTACT.  BECAUSE THE SPIDER IS STILL ROTATING SLOWLY, THE LOWER CONTACT AGAIN MAKES CONTACT WITH THE STATIONARY UPPER CONTACT, STARTING THE LEAD SCREW MOTOR AND TURNING THE UPPER CONTACT AWAY FROM THE LOWER CONTACT AGAIN BREAKING THE CONNECTION TO THE LEAD SCREW MOTOR.
14 THE MAKE AND BREAK CONTINUES TILL THE SPIDER AND LOWER CONTACT FINALLY STOP MOVING, THE LOWER DIFFERENTIAL GEAR HAVING REACHED A SPEED EQUAL AND OPPOSITE TO THE UPPER DIFFERENTIAL GEAR.
15 THE YOKE HAS RAISED THE ROLLER AND PINION TO THE POINT ON THE CONSTANT SPEED DISK BRINGING THE LOWER DIFFERENTIAL GEAR TO A SPEED EQUAL AND OPPOSITE TO THE UPPER DIFFERENTIAL GEAR, STOPPING ROTATION OF THE SPIDER.
WITH A CONSTANT RATE OF MILES TRAVELED BEING TRANSMITTED FROM THE ROTARY DISTANCE TRANSMITTER, THE DIFFERENTIAL SPIDER WILL REMAIN STATIONARY AND THE POINTER WILL INDICATE THE SPEED IN KNOTS.  ANY VARIATION IN THE RATE OF TRANSMISSION OF MILES TRAVELED WILL CAUSE THE UPPER DIFFERENTIAL GEAR TO ROTATE SLOWER OR FASTER THAN THE LOWER DIFFERENTIAL GEAR AND START THE SPIDER MOVING.  THIS IN TURN WILL CAUSE THE LEAD SCREW TO RAISE OF LOWER TO THE ROLLER AND PINION TO A POINT ON THE REVOLVING CONSTANT SPEED DISK WHICH WILL BRING THE DIFFERENTIAL GEARS TO THE SAME SPEED, BREAK CONTACT TO THE LEAD SCREW MOTOR AND STOP THE POINTER AT AN INDICATION OF THE SPEED AT WHICH THE MILES ARE BEING TRAVELED.


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