TECHNICAL FIELD

The invention relates to mechanical torque safety locking device that ensures the centre shaft, to which the rollers that enable the material to be pelletized in the pellet press to be compressed and transferred onto the pellet disk are attached, to remain stationary during pelletizing, and ensures the centre shaft, to which the rollers are attached, to start rotational motion together with the pellet disk by controlling the torque value for eliminating the tension that will occur on the rotor that causes the disc to rotate in case of large size or metal and similar hard foreign materials jammed between the rollers and the pellet disc.

PRIOR ART

The materials to be used in the manufacture of feed, fuel and raw materials can be used by turning them into pellets for easy storage, transportation, and long-term preservation of the material form. Pelletizing the materials is carried out by giving certain physical and chemical properties to the materials to be pelleted after subjecting them to different processing steps and by compression, shaping and cutting processes in the pellet presses.

The material to be pelleted is fed into the pellet presses after gaining suitable physical and chemical properties for pelletizing and is compressed by the rollers in the pellet press, and is pressed towards the pellet disc with pores, which is located on the outside of the rollers and has rotational movement through the rotor. Pellet formation is realized by cutting the material, which comes out of the pores in a certain diameter by being compressed by the rollers in the inner part of the pellet disc, in certain lengths by the blades positioned on the outer surface of the pellet disc according to the desired pellet dimensions.

In pellet presses, while the pellet disc, which enables the material to reach a certain diameter, rotates around its own axis, the central shaft, on which the rollers that ensure the compression of the material is positioned, is kept stationary. The compaction process is carried out in a healthy manner by keeping the central shaft stationary, to which the roller group that provides the compression is attached, while the rollers compress the material, between the rollers and the disk, outside of the disk by rotating around their own axis. Keeping the central shaft, to which the roll group is connected, stationary during normal operation of the pellet press is ensured by the safety pins positioned between the flange, to which the shaft is connected from its tailpiece, and the main bearing. In the event that any hard foreign object or hard and oversized material gets jammed between the rollers and the pellet disc during pelletizing, the safety pins, positioned between the centre shaft and the main bearing, break when the tension force on the rotor, to which the pellet disc is attached, reaches dangerous limits for the engine and the roller group starts to rotate with the pellet disc around the centre shaft axis. When the safety pins break and the center shaft starts to rotate, the power cut-off switches are activated and the machine is stopped. Thus, excessive torque accumulation on the rotor, to which the pellet disc is connected, is prevented and longer-term failures are avoided. Then, the remaining parts of the broken safety pins in the main bearing and the flange, to which the centre shaft is attached, are removed by the operators and the pellet press is brought back into operation by placing new safety pins.

Safety pins used in pellet presses in the current technique can be broken at certain tension levels by means of the notches formed on them. Here, the mechanical properties such as the width and depth of the notch formed on the pin are created by making calculations according to the desired torque limits, and the safety pins are broken as a result of the mechanical stresses due to the high torque generated in the pellet press, and the central shaft to which the roller group is attached starts to rotate, and the machine is stopped by means of safety switches. However, the safety pins used in the current technique cannot be mechanically operated within the torque range, and in this case, the machines are usually either stopped by breaking of the safety pins at normal operating voltages or they are not broken even at high torque values that pose a risk and hence causing major malfunctions in the rotor and electrical components. In these cases, production times and maintenance-repair costs increase.

In the pellet mill, which is the subject of document US5585124A, as mentioned above, the inner shaft on which the roller group is attached, is connected to the main body with safety pins, and in case of the abovementioned emergencies, these pins are broken and thereby it is ensured that the inner shaft, to which the roller group is attached, rotates together with the outer shaft.

Whereas in the document RO133484, it is aimed that the microswitch will be activated and shut down the system upon deformation of the disc springs under high tension, which are tightened with screws to the axle, to which the roller group is connected.

In our previous patent document with file no. TR202009306, a torque safety locking system is mentioned, in which hydraulic and mechanical compression elements are used together and the torque value is adjusted via hydraulic effect.

BRIEF DESCRIPTION OF THE INVENTION

A mechanical torque safety lock, whose safety torque value is controlled mechanically, has been developed in order to keep the centre shaft, on which the roller group is attached which is formed by the rollers that enable the materials to be pelletized in the pellet presses used for pelletizing the materials such as feed, fuel, raw materials to be compressed in the inner part of the pellet disk and transferred onto the disk, to remain stationary on the main body of the pellet press under normal operating conditions, and to start rotational motion together with the pellet disk to eliminate the tension that will occur on the rotor in case of large size or metal and similar hard foreign materials being jammed between the rollers and the pellet disc.

In the developed mechanical torque safety lock, the centre shaft cover (2), which the roller group is connected to, is kept stationary on the main body (1 ) by means of the lock lever (3). The locked and unlocked position of the lock lever (3) is controlled by the torque switch (4) connected to it. In the mechanical torque safety lock developed, locking at the desired torque level can be achieved by determining the desired maximum torque value on the centre shaft cover (2), on the torque switch (4) that limits the rotational movement of the lock lever (3).

FIGURES

Figure 1 . Mechanical Torque Safety Lock Overview

Figure 2. Mechanical Torque Safety Lock Overview

The corresponding part numbers in the figures are given below.

1 . Main Body

2. Centre Shaft Cover

2.1. Tab Slot

3. Lock Lever

3.1 . Lock Slot

3.2. Lock Tab

3.3. Body Attachment

4. Torque Switch

4.1 . Switch Connection

5. Movable Tab

6. Switch Slot

DETAILED DESCRIPTION OF THE INVENTION

The mechanical torque safety lock, which ensures that the rotational movement of the centre shaft around its own axis is limited to certain torque values in the pellet presses of the present invention; contains parts and sections of the central shaft cover (2) that incorporates the tab slot (2.1 ) formed on it to ensure the connection with the main body (1 ), the lock lever ( 3) that ensures the centre shaft cover (2) remain connected to main body (1 ) and limits its movement around its own axis, the torque switch (4) connected on the main body (1 ) to control the torque that may occur on the centre shaft and the release of the lock lever (3) from the locking position, movable tab (5) that provides the connection between the lock lever (3) and the torque switch (4) and rotates around its own axis and the switch slot (6) that ensures the connection of the torque switch on the main body (1 ).

On the central shaft cover (2) developed in the mechanical torque safety lock, which is the subject of the invention, there is at least one tab slot (2.1 ) formed in a manner to be connected with the lock tab (3.2) located on the lock lever (3). The tab slot (2.1 ) is the section that transfers the buckling stress formed on the centre shaft cover (2) to the lock lever (3) via the lock tab (3.2).

On the lock lever (3) developed in the mechanical torque safety lock, which is the subject of the invention; there are parts and sections of at least one lock slot (3.1 ) that ensures the connection of the lock lever (3) with the movable tab (5), at least one lock tab (3.2) that ensures the connection of the lock lever (3) with the tab slot (2.1 ) of the centre shaft cover (2), at least one body connection (3.3) that provides the connection of the lock lever (3) on the main body (1 ) and centres the rotational movement of the lock lever. Lock lever (3) is the part that transfers the buckling stress formed on the centre shaft cover (2) to the torque switch (4) via the movable tab (5).

The torque switch (4) developed in the mechanical torque safety lock, which is the subject of the invention, is the part that is connected to the main body (1 ) via the switch slot (6). The torque switch (4) is the part that is connected to the movable tab (5), which limits the rotational movement of the lock lever (3), via switch connection (4.1 ).

The movable tab (5) developed in the mechanical torque safety lock, which is the subject of the invention, is the part that is connected to the torque switch (4) via the switch connection (4.1 ). The movable tab (5) is the part that is connected to the lock lever (3) via the lock slot (3.1 ). The movable tab (5) is the part that rotates around its own axis so that the tension formed on the centre shaft cover (2) is transferred to the torque switch (4) via the lock lever (3). The switch slot (6) developed in the mechanical torque safety lock, which is the subject of the invention, is the part that enables the torque switch (4) to be connected to the main body (1 ).

A limit force value is determined via the torque switch (4) for the buckling stress that may occur on the centre shaft cover (2) in the mechanical torque safety lock, which is the subject of the invention. When the buckling stress occurring on the centre shaft cover (2), due to the reasons explained in the previous sections, reaches the determined values, this force is transferred to the movable tab (5) and from there to the switch connection (4.1 ) via the lock lever (3). Since the predetermined limit value is reached on the torque switch (4), the switch connection (4.1 ) allows the movable tab (5) to rotate around its own axis and the movable tab (5) performs the rotational movement. The lock lever (3) also performs the rotational movement centred on the body connection (3.3) depending on the rotational movement of the movable tab (5), and the lock tab (3.2) is separated from the tab socket (2.1 ). Thus, the central shaft cover (2), which is held stationary on the main body (1 ), can rotate around its own axis and the tensions that will occur on the rotor assembly are eliminated.

With the mechanical torque safety lock, which is the subject of the invention, there is no material consumption in the locking and post-locking processes, and the locking mechanism can be used continuously.