Method for adjusting screw gap of counter-rotating conical twin-screw extruderMethod for adjusting screw gap of counter-rotating conical twin-screw extruder
Install the front and rear supports on the barrel and put it on the mainframe together with the screw (installed in the barrel). First, do not install the locking nut. Shake the front support manual rocker to move the barrel in the direction of the distribution box. Look at the barrel stop Whether the lip of the distribution box is at the same level, it is preliminarily judged whether the barrel reaches the processing accuracy. As shown in Figure 1.
Remove the spline sleeve of the distribution shaft in the distribution box, and use a straight edge to measure whether the spline of the screw shank is parallel to the spline of the distribution shaft (front, back, left, and right). Increase and decrease the copper gasket at the front and rear support of the barrel to adjust the two spline shafts to the same horizontal position. as shown in picture 2.
Install the screw spline into the distribution box spline sleeve, and manually crank the motor rotation angle, remove the spline sleeve, and repeat the above measurement steps until they are in the same horizontal position at any angle (control within the error range of 0.05mm) .
4) Install the top shaft of the screw into the screw (without gasket).
5) Install the screw spline into the distribution shaft spline sleeve of the distribution box, then use the screw top plate to push the two screws towards the distribution box to the bottom to die, and then remove the screw top plate. As shown in Figure 4
6) Place the dial indicator on the small end of the barrel, place the probe head on the head of a screw (such as the left screw) and adjust the gauge position to zero.
7) Use a copper spudger to hold the right screw at the bottom of the discharge port (keep the end surface of the screw top shaft in contact with the end surface of the distribution shaft) and fix it.
8) Use a copper spudger to push the left screw toward the machine head until it cannot move, and then read the value a1 on the dial indicator.
9) Push the two screws to the top of the distribution shaft of the distribution box in the same way, pry the left screw against the right screw and read the value b1 at the head of the right screw.
10) After manually turning the motor to rotate 180 degrees, repeat the above steps to read the displayed values a2 and b2.
11) Calculate the difference between the thickness of the left and right screw gaskets: if the measured value a1=1.8mm, a2=2mm, b1=1.6mm, b2=1.8mm
The average movement of the left screw: (a1 a2)/2=(1.8 2)/2=1.9mm
The average movement of the right screw: (b1 b2)/2=(1.6 1.8)/2=1.7mm
Thickness difference between left and right screw gaskets: 1.9-1.7=0.2mm. It means that the left screw should add 0.1mm more thickness than the right screw when adding the gasket.
12) Measure the total clearance of the barrel screw: push the left and right screws (without gasket) to the distribution box to the bottom to die,
Place the dial indicator on the small end of the barrel, and place the probe head on any screw head to adjust the position to zero. At the same time, pry the left and right screws at the discharge port to die in the direction of the machine head,
Then read the displayed value C on the dial indicator (this value is the maximum movement of the screw in the barrel).