NL9302236A - Adjustment mechanism for a granulating mill - Google Patents

Abstract

The invention relates to a novel design for the adjustment of the press rolls of a granulating mill (roll press). This involves the use of an air motor (pneumatic motor) which is fitted on the housing of the granulating mill and, preferably via the main shaft of the granulating mill and via suitable worm wheel transmissions, drives servo cylinders for the press rolls. The press rolls are eccentrically mounted on press roll adjustment arms which are actuated by the servo cylinders.

Description

ADJUSTMENT MECHANISM FOR A GRAIN PRESS

The invention relates to an adjustment mechanism for a grain press.

Although various types of these are already known, the invention aims to propose improvements in this field.

To this end, the adjusting mechanism according to the invention is characterized in that it comprises an air motor driving eccentrically mounted press rollers.

With the help of the air motor, the adjustment of the press rollers can be effected effectively.

Preferred constructional embodiments are mentioned in the subclaims.

The invention will now be elucidated on the basis of the drawing, which shows a grain press provided with an adjusting mechanism according to the invention.

Hereby shows:

Fig. 1 a longitudinal section, and

Fig. 2 is a cross section at the position of the adjusting mechanism of the press rollers.

The drive of the system is a high-torque 2-way rotating air motor L This motor must be supplied with air of 6 bar pressure, oil lubricated and is placed at the rear of the gearbox. The motor is placed in a cylindrical housing 2, the so-called rotary coupling, which is flanged against a specially shaped intermediate piece 3, attached to the main shaft 4.

The specially shaped spacer 3 is required to allow removal of broken shear pins and install new pins.

The rotary coupling has swivels 7 on the outside, through which lubrication takes place of the various lubrication points in the machine, as well as of the adjusting mechanism itself. Connection for the air supply of the motor takes place at the swivels 6. If the shear pins break, the main shaft 4 rotates together with the motor I as usual, the connections 6.1 being stopped by an attachment to the gearbox. The air motor shaft is coupled to a connecting shaft 9 which runs through a central hole in the main shaft 4 and is coupled at the front to a worm shaft 10, cooperating with 2 worm wheels 5. Due to the chosen ratios, the worm wheels rotate 5 ± 20 rpm.

The worm wheels 5 are mounted on a special hollow shaft construction ü which is internally provided with ACME screw thread. A spindle 12 with externally corresponding ACME screw thread is arranged in each of the worm wheel shafts ü. One spindle, the top one leads to the right roller and the other to the left roller. Both are connected to the roller adjusters 13 on the roller shafts 15. Worm 10, worm wheel shafts, etc. are mounted in special bearings and built together in a stainless steel housing, fixed to the roller retaining plate 16.

Rotation of the worm wheel shafts Π. is thus converted into a linear movement of the spindles 12 with subsequent arcuate movement of the roller adjusters 13. The direction of rotation of the air motor 1 determines the direction of movement. The construction is such that the rollers 17 move eccentrically 15 to their die 18 via their roller axis as the spindles 12 move inward. This results in that the spindles 12 are only subjected to tensile stress when the greatest reaction forces occur. In the reverse direction of rotation, the rollers 17 move from the die 18 and the loads are small.

The full stroke of the spindles 12 causes an arc movement of the roller adjusters 13 of ± 40 degrees. The full stroke lasts for ± 1.5 min. In order to allow the spindles 12 to follow the arc movement of the roller adjusters 13. the worm wheel shafts H are fitted in special adjusting radial axial bearings 14, so that undesired loads on the spindle 12 and connection with roller adjusters 13.

Before proceeding to the rolling position indicator and operation, it should be noted that manual operation is possible in the event of a malfunction of the air motor or air equipment. Nothing needs to be changed for this. Roller adjustment can be achieved by placing a pneumatic wrench on the front end of the worm shaft with the door open.

A second note: small differences in roll diameters can be compensated for by slightly shortening the spindle of the largest roll. This can be done by loosening the connection with the roller adjuster and turning the spindle 180 ° or 360 ° inwards and repairing the connection.

(360 ° rotation represented ± 2 degrees from the positioner arc)

Large differences in roll diameters are undesirable and should be avoided.

If caused by uneven wear, it means uneven power, which also results in unbalanced forces and possible damage to other parts.

Roll die distance indication is realized as follows:

If the air motor is activated by operating the air valves via the push buttons on the control panel, a green light indicates whether the motor is running properly. The green light goes out when the engine is running at too low a speed.

The motor runs as long as the push button is pressed. The gauge (counter) on the panel shows that the rolls are being moved and in what direction from the zero point.

The zero point is the known point at which the rollers just touch "skiptouch".

Each time the rollers are put back in this position, (with clean die) e.g. after jamming or wear compensation, the gauge on the panel should be reset to zero.

Movement of the rollers from the die is considered a positive reading on the gauge. Towards the die as negative direction (+ and - on meter).

The distance indication is realized by the signals from 2 sensors 8 to the counter. One sensor counts the number of revolutions of the motor 1 pulse per rev. The other sensor also counts, but causes a phase shift according to the direction of rotation, which is indicated in the positive or negative sense on the counter.

The roll axis eccentric is responsible for ensuring that the roll distance to the die is not linear when turning, but depends on the arc segment in which the eccentric is located.

Therefore, the positioners are marked and show 10 equal segments.

Each subsequent segment is shifted 15 degrees from the previous segment.

(15 ° is one tooth adjustment on the roller shaft). To put a distance in mm on the panel. to read that is sufficiently linear and reliable for press practice, a separate correction factor must be entered in the meter for each segment. A table is available for this, so that the factor associated with each segment can be entered.

This is only important if you consciously want to work with a larger roll distance in order to influence the quality of the product and the position of the product by means of a large film thickness. roles wish to know. In situations where this roll adjustment is only used for wear compensation or restart after jamming, or roll or die change, the position indication of the rollers is less important.

Claims (4)

1. Adjusting mechanism for a pellet press, characterized in that this adjusting mechanism comprises an air motor driving eccentrically mounted press rollers. Adjusting mechanism according to claim 1, characterized in that the air motor is connected to the press rollers via the main axis of the pellet press. Adjusting mechanism according to claim 1 or 2, characterized in that the adjusting mechanism comprises adjusting cylinders driven by a worm gear, which drive the press rollers for adjustment thereof. Adjustment mechanism according to one of Claims 1 to 3, characterized in that the air motor is connected to the pellet housing by means of shear pins as an overload protection device.