TECHNICAL FIELD

Invention relates to preset torque safety lock mechanism that enables the steps for the central shaft, to which the rollers are attached, to start rotating together with the pellet disk to be performed in a controlled manner in order to eliminate the tension that may build up on the rotor that enables the rotation of the disc, in the event of the central shaft, to which the rollers that compress the materials to be pelletized in the pellet presses and transfer them to the pellet disc are attached, remaining stationary during pelletizing and large-size .or metal and similar hard foreign substances jamming between rollers and pellet disk.

PRIOR ART

Materials to be used in the production of feed, fuel and raw materials can be used as pellets for purposes such as easy storage, transportation and preservation of the material form for long periods. Pelletizing of materials is performed by adding certain physical and chemical properties to the materials to be pelletized after different processing steps and by compressing, shaping and cutting processes within the pellet presses.

The material to be pelletized is fed to the pellet presses after gaining appropriate physical and chemical properties for pelletizing and compressed by the rollers inside the pellet press and pushed towards the pellet disc with pores, located on the outer part of the rollers, and rotated by means of the rotor. Pellets are formed by cutting the material, which comes out of the pores in a certain diameter by being compressed by the rollers inside the pellet disc, in certain lengths with the blades positioned according to the desired pellet dimensions on the outer surface of the pellet disc.

In pellet presses, while the pellet disk, which enables the material to reach a certain diameter, rotates around its own axis, whereas the central shaft on which the rollers are positioned to compress the material is kept stationary. While the rollers rotate around their own axes and squeeze the material between the roll and the disc outward from the disc, whereas the central shaft to which the roller group is connected is kept constant so as to ensure that the compression process is performed properly. In case the pellet press operates under normal conditions, the central shaft to which the roller group is attached is kept fixed by the safety pins positioned between the main bearing and the flange to which the shaft is connected from the tail part. If any hard foreign particle or hard and large-sized material is stuck between the rollers and the pellet disc, then when the tension force on the rotor to which the pellet disc is connected reaches dangerous limits for the motor, the safety pins positioned between the centre shaft and the main bearing break and the roller group also starts to rotate along the centre shaft axis with the pellet disc. When the safety pins break and the central shaft start 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 attached is prevented and long-term failures are avoided. Afterwards, the parts of the broken safety pins remaining on the main bearing and the flange, to which the central shaft is connected, are removed by the operators and the pellet press is put into operation again by placing new safety pins.

In the current technique, the safety pins used in pellet presses can be broken at certain stress levels by means of notches formed on them. Here, the mechanical properties such as the width and depth of the notch formed on the pin are calculated 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 connected starts to rotate and the machine is stopped by means of safety switches. However, the safety pins used in the current technique cannot be operated mechanically in the range of torque values, and in this case, the machines are either stopped by the breakage of the safety pins at normal operating voltages or not breaking even at high torque values that pose a risk, and causing major malfunctions in the rotor and electrical parts. In these cases, production times and maintenance-repair costs increase.

In the pellet mill, which is the subject of Document No.US5585124A, the inner shaft on which the roll group is located is connected to the main body with safety pins as mentioned above, and in case of emergency, these pins are broken and the inner shaft, to which the roll group is connected, is rotated together with the outer shaft as we mentioned hereinabove.

Whereas in the document No. R0133484, it is aimed that the disc springs tightened with a screw on the axle, to which the roller group is connected, are deformed under high tension, and the microswitch is activated to turn off the system.

BRIEF DESCRIPTION OF THE INVENTION

Preset torque safety lock mechanism has been developed to enable the centre shaft, on which the roller group formed by the rollers that transfer the material to be pelletized in pellet presses used for pelletizing materials such as feed, fuel, raw materials by squeezing them in the inner part of the pellet disk, to start rotating together with the disk in order to eliminate the high torque tension that will occur on the rotor, to which the disc is attached, due to the centre shaft remaining stationary on the main body under normal operating conditions and the jamming of any foreign material between rollers and the disk.

Hydraulic and mechanical pressure components are used together in the developed preset torque safety lock mechanism. The compressive force created by the hydraulic fluid contained in the hydraulic chamber (3) located inside the lock main body (1) is transferred to the pressure spring (6) and the locking pin (7) connected to the spring (6) is positioned on the strike plate (8). The central shaft, to which the roller group is attached, is kept stationary on the main body while the lock pin (7) is connected to the strike plate (8). The lock pin (7) connected to the strike plate (8) is pressed towards the inner part of the lock main body (1) and is separated from the strike plate (8) as a result of the tension created on the center shaft, to which the roll group is attached, due to any jamming between the rollers and the pellet disc, and the centre shaft is allowed to start the rotational movement together with the pellet disc. Thus, excessive torque accumulation on the rotor to which the pellet disc is attached is prevented. After the lock pin (7) released from the strike plate (8), the rotation movement of the centre shaft together with the pellet disc is detected by the safety switches and the operation of the system is stopped and the machine is prevented from getting damaged.

In the developed preset torque safety lock mechanism, the operating pressure values can be specified and the healthy working continuity of the pellet press can be ensured as the connection of the lock pin (7) with the strike plate (8) can be adjusted hydraulically via the pressure spring.

The developed preset torque safety lock mechanism is designed and manufactured in a way that it can be applied on all machines using safety pins to ensure torque safety. MEANING OF THE FIGURES

Figure 1. Torque Safety Lock Mechanism Sectional View

The part numbers given in the figures are provided below.

1. Lock Main Body

2. Pressure Adjustment Hand Wheel

2.1. Pressure Adjustment Spindle

3. Hydraulic Reservoir

4. Pressure Measurement Slot

5. Piston

6. Pressure Spring

7. Locking Pin

7.1. Conical tip

8. Strike Plate

8.1. Conical Slot

9. Manometer DETAILED DESCRIPTION OF THE INVENTION

The preset torque safety lock mechanism, which is the subject of the invention, developed in pellet presses to enable the steps for the central shaft, to which the rollers are attached, to start rotating together with the pellet disk to be performed in a controlled manner in order to eliminate the tension that may build on the disk rotor, in the event of the central shaft, to which the rollers are attached, remaining stationary independently of the pellet disk under normal operating conditions, and in the event of any hard large-size substance jamming between the rollers and the pellet disk; contains the lock main body (1), which is manufactured in a hollow structure so that the hydraulic and mechanical pressure equipment of the locking mechanism can be positioned inside it, pressure adjustment hand wheel (2) providing the forward and backward movement of the pressure adjustment spindle (2.1) attached to it, hydraulic reservoir (3) in which hydraulic fluid is placed, pressure measurement slot (4) where pressure measurement equipment can be placed inside the main body (1) to measure the value of the pressure formed inside the main body (1), the piston (5) that enables the transfer of the pressure of the hydraulic fluid to the pressure spring (6), The compression spring (6) positioned between the piston (5) and the locking pin (7), the locking pin (7) with a conical tip (7.1) on it and the parts and sections of the lock strike plate (8) on which a conical socket (8.1) is formed.

The lock main body (1) developed in the preset torque safety lock mechanism, which is the subject of the invention, is positioned on the flange connected to the tail part of the centre shaft where the pressure rollers in the pellet press are grouped together.

The pressure adjustment hand wheel (2) developed in the preset torque safety lock mechanism, which is the subject of the invention, is positioned on the lock main body (1). The pressure adjustment hand wheel (2) is moved in a circular motion and provides the back and forth movement of the pressure adjustment spindle (2.1) towards the hydraulic reservoir (3) inside the lock main body (1). The compression force desired to be created on the hydraulic fluid in the hydraulic reservoir is achieved by moving the developed pressure adjustment spindle (2.1) back and forth towards the hydraulic reservoir (3) inside the lock main body (1) by means of the circular movement of the pressure adjustment hand wheel (2). In another embodiment of the preset torque safety lock mechanism, which is the subject of the invention, the motor, which can be controlled by automation to be utilized instead of the pressure adjustment hand wheel (2), is positioned on the lock main body (1) and connected to the pressure adjustment spindle (2.1). In this way, the forward and backward movement of the pressure adjustment spindle (2.1) towards the hydraulic reservoir (3) inside the lock main body (1) is adjusted and controlled by the motor through the automation system.

The hydraulic reservoir (3) developed in the preset torque safety lock mechanism, which is the subject of the invention, is formed in a hollow structure so that the hydraulic fluid, enabling the transfer of the value of the pressure set with the pressure adjustment spindle (2.1) driven by the motor that can be controlled with pressure adjustment hand wheel (2) or by automation to the piston (5) and the pressure spring ( 6), can be placed inside it.

Pressure measurement slot (4) developed in the preset torque safety lock mechanism, which is the subject of the invention, is manufactured as the section that allows preferably manometer (9) or preferably PLC controlled pressure safety valve apparatus to be positioned on it to measure the value of the pressure created on the on the hydraulic fluid contained in the hydraulic reservoir (3) and display it over the lock main body (1 ).

The piston (5) developed in the preset torque safety lock mechanism, which is the subject of the invention, enables the pressure effect on the hydraulic fluid, the value of which can be set through the pressure adjustment spindle (2.1) driven by the motor that can be controlled with the pressure adjustment hand wheel (2) in the hydraulic reservoir (3) or by automation, to be transferred to the compression spring (6).

The compression spring (6) developed in the preset torque safety lock mechanism, which is the subject of the invention, is positioned between the piston (5), which transfers the pressure force created on the hydraulic fluid to it, and the locking pin (7). The compression force applied by the piston (5) on the pressure spring (6) is the operating pressure value set through the pressure adjustment spindle (2.1) driven by the motor that can be controlled by the pressure adjustment hand wheel (2) or automation, and if the compression force on the locking pin (7) coming from the strike plate side is higher than value of the pressure on the piston, then the pressure spring (6) compresses towards the piston (5) and enables the locking pin (7) to be released from the strike plate (8).

On the locking pin (7) developed in the preset torque safety lock mechanism, which is the subject of the invention, a conical tip (7.1) is formed enabling it to remain stationary inside the conical slot (8.1) formed on the strike plate (8). While the conical tip (7.1) is located inside the conical slot (8.1) formed on the lock strike plate (8), the central shaft, on which the roller group is attached is kept stationary as connected to the pellet press main body, independently of the rotary pellet disc.

The strike plate (8) developed in the preset torque safety lock mechanism, which is the subject of the invention, is positioned on the main body of the pellet press. On the strike plate (8) located on the pellet press main body, there is a conical slot (8.1), in which the conical tip (7.1) of the locking pin (7) will be positioned.

Thanks to the use of the preset torque safety lock mechanism, which is the subject of the invention, on the pellet press, in the event of any hard or large parts jamming between the compression rollers and the pellet disc, the conical tip (7.1) on the locking pin (7) is forced out of the conical slot (8.1) formed on the strike plate (8), and the locking pin (7) pulls back by creating pressure towards the pressure spring (6). Thus, the attachment between the locking pin (7) and the strike plate (8) ends, and the centre shaft begins to rotate together with the pellet disc, and hence the excessive torque tension that may occur on the pellet disc rotor is prevented, which in turn prevents the pellet press from getting damaged. When the conical tip (7.1) on the locking pin (7) releases from the conical slot (8.1) on the strike plate (8) and the centre shaft starts to rotate, the rotational motion is detected by the safety switches and the pellet press is stopped. The pellet press is then restarted after the fault causing the jam is removed.

The safety lock mechanism becomes available for reuse after the conical tip of the locking pin (7) is placed in the conical slot of the strike plate (8), as the preset torque safety lock mechanism, which is the subject of the invention, does not work due to the deformation of any part as in the cases of the mechanical safety pins used in the current technique. In addition, the appropriate upper pressure limit depending on the product to be pelletized can be set by displaying and setting the value of the pressure, where the locking pin (7) can remain in a stationary position on the strike plate (8), via the pressure adjustment hand wheel (2) and preferably via manometer (9) or preferably via the PLC controlled pressure relief valve positioned in the pressure measurement slot (4).