Beck, R&J Automobile Parts 14-10 Benutzerhandbuch

18

OPERATION

 

All models of the Beck Group 14 electronic 

control drive have individual, cast aluminum 
compartments for the main components: The 
control motor, wiring terminal board, drive 
train, electronic signal receiver, and feedback 
section.  Gasketed covers and sealed shafts 
make this product ideally suited to outdoor and 
high-humidity environments.
 

 

The Beck control motor is a synchronous 

inductor motor that operates at a constant 
speed of 72 RPM in synchronism with the line 
frequency.
 

Motors are able to reach full speed within 25 

milliseconds and stop within 20 milliseconds; 
actual starting and stopping times will vary with 
load.
 

Beck motors have double grease-sealed 

bearings and require no maintenance for the life 
of the motor.

 

The Group 14 drive train consists of a control 

motor, SLM, Handwheel, reduction gears, main 
gear, and power screw output shaft.  The ductile 
iron main gear and the bronze nut and stainless 
steel power screw output shaft are common to 
units of a particular range of thrust and timing.  
The steel reduction gears are part of the field 
changeable gear housing assembly.  Different 
combinations of output gear, housing assemblies, 
and drive motors determine the drive’s output 
thrust and timing. 
  The output shaft travel is limited by 
mechanical stops.  The mechanical stop for 
the fully extended or lower limit of the output 
shaft travel is not adjustable.  The position of 
the retracted or upward travel mechanical stop 
is determined by the number of washers on the 
output shaft between the Tight-Seater™ and the 
lower bearing plate.  This is factory-set for the 
amount of travel specified at the time of the order 
and is generally not changed in the field.
 

The amount of output shaft travel is determined  

by the setting of the Calibar.  Moving the Calibar 
block away from the output shaft increases the 
radius where the ball bearing contacts the sector 
gear lever.  The longer the radius the longer the 
vertical stroke of the output shaft for the same 
amount of rotation of the control end shaft.  
Therefore, the Calibar changes the output shaft 
travel but makes it unnecessary to change the 

switch cams, film potentiometer, or CPS-2.  Field 
Calibar adjustment is generally used to shorten 
the travel.  Consult the factory if a longer stroke is 
required.
 

 

An integral part of every Group 14 control 

motor is the self-locking mechanism.  This 
mechanical device couples the motor to the 
gear train and transmits full motor torque when 
rotated in either direction.  When the motor is 
de-energized, it instantaneously locks and holds 
the output shaft in position.

 

The Beck Tight-Seater™ assembly is a 

pre-loaded coupling that is installed between 
the drive output shaft and the valve stem.  It 
produces a controlled positive pressure against 
the valve seat, independent of drive thrust.
 

The Tight-Seater™ consists of four parts:  A 

housing attached to the output shaft, linear thrust 
discs contained in the housing, a flanged coupling 
attached to the valve stem, and a threaded ring 
to contain the flanged coupling in the housing 
and to allow adjustment of the pre-load on linear 
thrust discs.
 

The factory pre-load, by a threaded ring, 

ensures that no relative motion occurs between 
the flanged coupling and housing during normal 
valve operation until the pre-load thrust is 
exceeded in the seated plug position of the 
valve.
 

When the seated plug position of the valve is 

reached, the flanged coupling on the valve stem 
is stationary, and the output shaft exceeds the 
pre-load pressure of the Tight-Seater™.  When 
the pre-loaded pressure is exceeded, the housing 
will compress the linear thrust discs, maintaining 
a controlled pressure on the valve seat, with the 
shaft stationary.