JP2012106194A - Decanter type centrifugal concentrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent a differential speed device from being damaged when frictional force between a rotating bowl and a screw conveyor is increased.SOLUTION: The inside of the rotating bowl 1 rotated and driven by a single drive device 10 includes the screw conveyor 4 rotated and driven coaxially at a differential speed. A bowl rotating shaft 1C of the rotating bowl 1 and a screw rotating shaft 4D of the screw conveyor 4 are respectively provided with a bowl rotating pulley 15 and a screw rotating pulley 16. A drive shaft 10A of the drive device 10 is provided with a bowl driving pulley 11 and a screw driving pulley 12 respectively connected to the bowl rotating pulley 15 and the screw rotating pulley 16. Among these, the screw driving pulley 12 and the drive shaft 10A are mounted so as to be integrally rotatable through a shear pin 14 and so as to be rotatable relatively to each other around an axis X of the drive shaft 10A by fracture of the shear pin 14.

Description

  The present invention includes a screw conveyor that is driven to rotate around a coaxial line at a differential speed with the rotating bowl inside a rotating bowl that is driven to rotate about an axis by a driving device, and separates solids such as sludge by centrifugal force. It is related with the decanter type | mold centrifugal concentrator which concentrates.

  In such a decanter type centrifugal concentrator, for example, as described in Patent Document 1, the rotating shaft rotates to the opposite ends in the axial direction of the bowl rotating shaft of the rotating bowl and the screw rotating shaft of the screw conveyor. It is known that pulleys are attached, and drive pulleys of individual drive devices (motors) are connected to these rotary pulleys via belts. Here, the rotating pulley of the screw conveyor is connected to the screw rotating shaft through a gear box.

  On the other hand, in addition to the rotational drive of the rotating bowl and the screw conveyor by separate drive devices, for example, in Patent Documents 2 to 4, the bowl rotational shaft and the screw rotational shaft are connected to a differential speed device (gear box). In this case, the screw conveyor is rotated by rotating the bowl rotating shaft by a single driving device, while generating a differential speed with the rotating bowl by this differential speed device. ing. In such a decanter type centrifugal concentrator, since only one drive device is required, energy saving and cost reduction can be achieved.

  By the way, in such a decanter type centrifugal concentrator, when the frictional force between the rotating bowl and the screw conveyor is increased due to, for example, clogging of the concentrated sludge due to the concentration of the supplied sludge, it is connected to the screw conveyor. The load on the gear box increases, and in some cases, the gear box may be damaged. In this regard, in the decanter type centrifugal concentrator described in Patent Document 1 in which the rotating bowl and the screw conveyor are rotated by different driving devices, the load current of the driving device (motor) of the screw conveyor is detected, Based on the above, the sludge supply is stopped and the rotation of the rotating bowl is slowed down, or the differential speed between the rotating bowl and the screw conveyor is increased to facilitate the discharge of the sludge.

  On the other hand, in the decanter type centrifugal concentrator described in Patent Documents 2 to 4 in which the rotating bowl and the screw conveyor are rotationally driven by a single driving device, as in the decanter type centrifugal concentrator described in Patent Document 1. Since only the load corresponding to the screw conveyor of the driving device cannot be detected alone, for example, Patent Document 2 includes a load releasing device in the gear box, and at the same time the rotational torque of the screw conveyor reaches a predetermined value. Release the restraint between the bowl rotating shaft and screw rotating shaft in the gear box to eliminate torque transmission from the rotating bowl to the screw conveyor, or detect the rotational torque of the screw conveyor with a load cell, torque converter, limit switch, etc. Based on this, it is described that the supply amount of the supplied sludge and the like is controlled.

  Also, in Patent Document 3, a shear pin is provided in the drive transmission portion of the differential speed device, and when an excessive load is applied, the shear pin is broken to eliminate the rotational difference between the rotating bowl and the screw conveyor, or to the differential speed device with torque. An overload detection mechanism such as an arm is provided to electrically stop the centrifugal concentrator by a limit switch, or the friction force of the screw conveyor is detected as a change in air pressure applied to the torque arm provided in the differential speed device. It describes that the concentration of the supplied sludge is diluted based on the air pressure.

Japanese Patent No. 2973458 JP-A-53-91465 JP-A-56-62561 JP-A-9-57152

  However, even in a decanter type centrifugal concentrator that rotationally drives the rotating bowl and the screw conveyor by a single driving device as in Patent Documents 2 to 4, the pulley of the bowl rotating shaft is connected to the driving shaft of this driving device. And a screw driving pulley connected to the pulley of the screw rotating shaft and the screw rotating pulley, respectively, and the rotating bowl is directly driven by the rotation of the driving shaft, and the screw conveyor is connected to the screw rotating shaft and the screw rotating pulley. In a decanter-type centrifugal concentrator that is rotated via a differential speed device provided therebetween, when the load on the gear box increases, the load release device provided in the gear box described in Patent Document 2 or Patent Document 3 The bowl pin and the screw rotary shaft are released by the shear pin provided in the differential speed device described in It is not possible so as to eliminate the rotational difference between the Kurio conveyor.

  Similarly, the load concentrator described in Patent Document 2, torque converter, limit switch, torque arm described in Patent Document 3, and the like detect the rotational torque and frictional force of the screw conveyor to stop the centrifugal concentrator. It is also impossible to do. On the other hand, even if the load current of the driving device is detected as in Patent Document 1, since the detection result is the sum of the driving power of the rotating bowl and the screw conveyor, only the load for the screw conveyor is detected alone. I can't do it.

  For this reason, in such a decanter type centrifugal concentrator, when the frictional force between the rotating bowl and the screw conveyor increases and a load exceeding the rated torque acts on the differential speed device, for example, the screw drive pulley of the drive device and the screw rotation Measures are taken to protect the differential speed device by, for example, stopping the concentrator based on the detection of a decrease in the differential speed caused by slippage in the V-belt connecting the shaft screw pulley. Inevitably, such protective means may cause damage due to an excessive load acting on the differential speed device until the differential speed is reduced due to slip or the like.

  The present invention has been made under such a background. A bowl driving pulley and a screw connected to a driving shaft of a single driving device and a bowl rotating pulley of a rotating bowl and a screw rotating pulley of a screw conveyor, respectively. In a decanter type centrifugal concentrator equipped with a drive pulley, it is possible to reliably prevent the differential speed device from being damaged when the frictional force between the rotating bowl and the screw conveyor increases due to clogging of sludge, etc. An object of the present invention is to provide a decanter type centrifugal concentrator that can be used.

  In order to solve the above-mentioned problems and achieve such an object, the present invention is driven to rotate coaxially with a speed difference between the rotating bowl and a rotating bowl driven by a single driving device. A decanter-type centrifuge provided with a screw conveyor, wherein a bowl rotating pulley and a screw rotating pulley are provided on a bowl rotating shaft of the rotating bowl and a screw rotating shaft of the screw conveyor, respectively, and a driving shaft of the driving device Are provided with a bowl driving pulley and a screw driving pulley respectively connected to the bowl rotating pulley and the screw rotating pulley, and the screw driving pulley and the driving shaft can be integrally rotated via a shear pin. In addition, the shear pins are broken so that they can rotate relative to each other around the axis of the drive shaft. And characterized by being Attach.

  In the decanter type centrifugal concentrator configured as described above, when the frictional force between the rotating bowl and the screw conveyor increases, the rotation speed of the bowl rotating shaft of the rotating bowl and the screw rotating shaft of the screw conveyor that should be rotated with a differential speed is reduced. As it approaches, the bowl drive pulley and screw drive provided on a single drive shaft in a single drive unit connected to the bowl rotary shaft and screw rotary pulley provided on the bowl rotary shaft and screw rotary shaft, respectively. A load acts between the drive shaft to which the bowl drive pulley is attached and the screw drive pulley so that a differential speed is generated between the pulley and the rotation speed (number of rotations).

  When the load exceeds a predetermined magnitude, the shear pin is broken, and thereafter, the drive shaft and the screw drive pulley are rotatable relative to each other, so that the drive force is transmitted from the drive shaft to the screw drive pulley. Since no driving force acts on the screw rotating pulley and the screw rotating shaft, the screw conveyor is rotated at a rotational speed (number of rotations) substantially equal to that of the rotating bowl by the frictional force. For this reason, since the load does not act on the differential speed device provided on the screw conveyor, for example, even if the concentration device is stopped after detecting the decrease in the differential speed due to the breaking of the shear pin, the differential speed device is damaged. Can be prevented from occurring.

  Further, in the shear pin, by forming a constricted portion between the screw drive pulley and the drive shaft, breakage when the above-described load acts on the shear pin is likely to occur from the constricted portion. Therefore, by appropriately setting the outer diameter of the shear pin in the constricted portion according to the rotational driving force of the driving device and the properties of the processing object such as sludge to be concentrated, the differential speed device is not damaged. It becomes possible to transmit the rotational driving force from the driving device to the screw conveyor reliably and efficiently.

  Furthermore, the screw drive pulley may be attached to the drive shaft via a bearing so that the shear pin is broken so that the screw can be rotated relative to the drive shaft around the axis of the drive shaft. The screw rotation pulley, screw rotation shaft, and screw conveyor can be smoothly rotated at substantially the same rotational speed as the rotating bowl, while the screw drive pulley is stably supported by the drive shaft even after the shear pin is broken. It becomes.

  As described above, according to the present invention, the bowl drive pulley and the screw drive pulley are provided on the single drive shaft of the single drive unit, and the rotary bowl, the screw conveyor, In a decanter type centrifugal concentrator that saves energy and lowers costs by driving the machine, even if the frictional force between the rotating bowl and the screw conveyor increases due to clogging of the workpiece such as sludge, the differential speed It is possible to reliably prevent damage caused by an excessive load acting on the apparatus.

It is a plane sectional view showing one embodiment of the present invention. It is an expanded sectional view of the bowl drive pulley and screw drive pulley part of the drive device in the embodiment shown in FIG.

  1 and 2 show an embodiment of the present invention. In the present embodiment, the rotating bowl 1 has a substantially cylindrical shape with a substantially constant inner and outer diameter centered on an axis O on which the bowl body 1A is horizontally disposed, and both ends of the bowl body 1A are coaxial. It is closed by the annular plate-like portion 1B centered on O, and further, from the central portion of these annular plate-like portions 1B, a hollow shaft-shaped bowl rotating shaft 1C centering on the axis O is also provided along the axis O. The bowl rotating shaft 1C is attached to the bearing 2 so as to extend outward, and the rotating bowl 1 is supported on the base 3 so as to be rotatable around the axis O.

  A screw conveyor 4 is accommodated inside the rotating bowl 1. The portion of the screw conveyor 4 accommodated in the bowl main body 1A is a screw conveyor main body 4A, and the screw conveyor main body 4A is disposed coaxially with the axis O with a slightly smaller outer diameter than the bowl main body 1A. The screw blade 4C having an outer diameter slightly smaller than the inner diameter of the bowl body 1A is provided on the outer periphery of the substantially cylindrical conveyor shaft 4B. The conveyor shaft 4B has a constant outer diameter from one end portion (left end portion in FIG. 1) to the other end portion (right end portion in FIG. 1) in the axis O direction. The other end portion has a truncated cone shape whose outer diameter gradually increases toward the other end.

  Further, at the center of both ends of the conveyor shaft 4B of the screw conveyor body 4A, a hollow shaft-shaped screw rotating shaft 4D that is coaxial with the conveyor shaft 4B is disposed inside the bowl rotating shaft 1C that is also formed into a hollow shaft. The screw conveyor 4 is provided so as to extend outward along the axis O through the periphery, and the screw rotating shaft 4D is attached to the inner peripheral portion of the bowl rotating shaft 1C via the bearing 5, whereby the screw conveyor 4 rotates. The rotary bowl 1 is supported so as to be rotatable around an axis O coaxial with the bowl 1 and to be rotatable relative to the rotary bowl 1 around the axis O. The outer periphery of the bowl main body 1A of the rotating bowl 1 and the space between the annular plate-like portion 1B and the bearing 2 are covered with a cover 6.

  Thus, the bowl rotating shaft 1C and the screw rotating shaft 4D, which are hollow shafts, are configured such that the screw rotating shaft 4D protrudes outward from the bowl rotating shaft 1C at both ends in the axis O direction. Among these, a to-be-processed object, such as sludge, is supplied through the inner peripheral part of the screw rotating shaft 4D on the one end side. That is, one end of the screw rotating shaft 4D on the one end side is connected to a supply source of an object not shown via the rotary joint 7, and the other end is a conveyor shaft 4B of the screw conveyor body 4A. Is connected to a supply pipe 4E disposed along the axis O, and the supply pipe 4E is bent to the outer peripheral side at a substantially central portion in the axis O direction of the screw conveyor body 4A to be formed on the outer peripheral surface of the conveyor shaft 4B. Opened.

  As described above, the bowl body 1A of the rotating bowl 1 and the conveyor shaft 4B of the screw conveyor body 4A of the screw conveyor 4 are connected to each other from the supply source via the inner peripheral portion of the screw rotating shaft 4D and the supply pipe 4E. As will be described later, the object to be processed supplied to the space between them is solid-liquid separated by centrifugal force by rotating the rotating bowl 1 and the screw conveyor 4 at a high speed with a slight difference speed, and the solid content is screwed. While being conveyed to the other end side by the blades 4C, the liquid is sent to the one end side.

  Here, a discharge passage 4F for the liquid is formed in the screw rotating shaft 4D on the one end side. The discharge passage 4F opens to the outer peripheral surface of the screw rotation shaft 4D located on the inner peripheral side in the bowl main body 1A on the one end side, and the outer peripheral surface and the inner peripheral portion to which the workpiece is supplied. The liquid that extends toward the one end side in the screw rotation shaft 4D between them, is opened in the liquid discharge box 8 provided in front of the rotary joint 7, and is sent out toward the one end side. The minute is discharged and collected.

  On the other hand, the screw rotation shaft 4D on the other end side has an inner peripheral portion itself serving as a solid content discharge path 4G. That is, the solid content discharge passage 4G also opens to the outer peripheral surface of the screw rotation shaft 4D located on the inner peripheral side in the bowl main body 1A on the other end side, reaches the inner peripheral portion, and further along the axis O. After extending to the other end portion side, it is opened in the solid content discharge box 9 provided at the other end of the screw rotating shaft 4D on the other end side, and the separated and transported solid content is discharged and collected. It is made to do.

  In this embodiment, such a rotating bowl 1 and the screw conveyor 4 are rotated at high speed by a single drive device 10. The drive device 10 is an electric motor, and the axis X of the drive shaft 10A is parallel to the axis O of the rotary bowl 1 and the screw conveyor 4, and the drive shaft 10A is directed toward the one end in the direction of the axis O. The rotary bowl 1 and the screw conveyor 4 are disposed on the side of the one end portion side.

  At one end of the drive shaft 10A of the drive device 10, a bowl drive pulley 11 for rotating the bowl rotation shaft 1C and a screw drive pulley 12 for rotating the screw rotation shaft 4D are provided at one end side in the axis X direction. They are attached in this order toward (left side in FIGS. 1 and 2). Of these, the bowl drive pulley 11 has a larger diameter than the screw drive pulley 12 and is fixed to the drive shaft 10A via a key (not shown) or the like so that it can always rotate integrally with the drive shaft 10A.

  On the other hand, the screw drive pulley 12 is attached to the outer periphery of the drive shaft 10A via a bearing 13 as shown in FIG. 2, and in this state, the screw drive pulley 12 is relative to the drive shaft 10A around its axis X. It is supposed to be rotatable. As the bearing 13, a rolling bearing, a sliding bearing, or the like can be used. However, a holder 12A is attached to one end of the screw drive pulley 12 so as to surround the end face of the drive shaft 10A. The holder 12A and the drive shaft 10A are connected via a shear pin 14. Thus, the screw drive pulley 12 can be rotated integrally with the drive shaft 10A via the shear pin 14 when the shear pin 14 is not broken.

  The shear pin 14 is formed of, for example, a copper alloy, which is a material having a lower strength than the drive shaft 10A, the bowl drive pulley 11, the screw drive pulley 12, and the holder 12A, which are made of steel or the like. Yes. Further, both end portions 14A of the shear pin 14 in the direction of the axis X are formed into a regular polygonal column shape such as a regular quadrangular prism shown in FIG. 2, for example, and the both ends 14A are connected to the holder 12A and the drive shaft. The screw drive pulley is formed by fitting the cross section formed along the axis X on the end face of the one end portion of 10A into the regular polygonal fitting holes 12B and 10B having the same square shape as the both end portions 14A. 12 can rotate integrally with the drive shaft 10A. It should be noted that both end portions 14A of shear pin 14 and fitting holes 12B and 10B may be other than a regular polygon in cross section as long as they can be fitted to each other and can be integrally rotated.

  On the other hand, between the both end portions 14A of the shear pin 14, the both end portions 14A are positioned between the end face on the one end side of the drive shaft 10A and the holder 12A attached to the screw drive pulley 12. A constricted portion 14B is formed that is constricted with respect to the regular hexagonal column formed by the inner diameter of the regular hexagonal column and has a reduced outer diameter. The constricted portion 14B has a cross section orthogonal to the axis X, for example, a circle having a smaller diameter than a circle inscribed in the regular hexagon formed by the both ends 14A, and circulates around the axis X with a constant width in the axis X direction. An annular groove having a “U” cross section is formed.

  As described above, the bowl drive pulley 11 directly fixed to the drive shaft 10A and the screw drive pulley 12 attached via the shear pin 14 include the bowl rotation pulley 15 provided on the bowl rotation shaft 1C, and the screw rotation shaft. It is connected to a screw rotation pulley 16 provided in 4D via V belts 17 and 18, respectively. The bowl rotating pulley 15 has a larger outer diameter than the screw rotating pulley 16, but the outer diameter ratio is different from the outer diameter ratio that the bowl driving pulley 11 forms with respect to the screw driving pulley 12. Specifically, in this embodiment, the outer diameter ratio between the bowl driving pulley 11 and the screw driving pulley 12 is made larger than the outer diameter ratio between the bowl rotating pulley 15 and the screw rotating pulley 16, and this also causes the bowl to rotate. A differential speed is generated between the rotating shaft 1C and the screw rotating shaft 4D.

  Further, the V belt 17 wound around the bowl driving pulley 11 and the bowl rotating pulley 15 is wider than the V belt 18 wound around the screw driving pulley 12 and the screw rotating pulley 16, and the number of the peaks is large. In accordance with this, as shown in FIG. 2, the bowl drive pulley 11 and the bowl rotation pulley 15 are also wider in the axis O and X directions than the screw drive pulley 12 and the screw rotation pulley 16, and are individually The V-groove is large and the number of V-grooves is also increased.

  The screw rotation pulley 16 that is driven to rotate by the screw drive pulley 12 of the drive device 10 through the V belt 18 in this way is connected to the screw rotation shaft 4D of the screw conveyor 4 via the differential speed device 19, and this differential speed. By means of the device 19, a difference of a predetermined rotational speed (rotational speed), that is, a differential speed is generated between the rotary bowl 1 connected to the bowl rotary pulley 15 and driven to rotate, and the screw conveyor 4. The differential speed device 19 is a reduction gear (gear box) in which planetary gears are incorporated in a plurality of stages.

  In the decanter type centrifugal concentrator configured as described above, the rotating bowl 1 and the screw conveyor 4 are first driven to rotate by a single driving device 10. Compared with the rotational drive of the screw conveyor, it is possible to achieve energy saving, cost reduction, space saving and the like of the concentrator as a whole.

  Further, due to a change in the properties of an object to be treated such as sludge to be concentrated, solid content is clogged between the rotating bowl 1 and the screw conveyor 4 and the frictional force between the two becomes large. When the rotational speeds of the rotary bowl 1 and the screw conveyor 4 to be rotated at a high speed approach each other, a load is generated on the differential speed device 19 that causes the differential speed, and the differential speed device 19 is connected to the load. The differential speed given to the screw rotary pulley 16 and the bowl rotary pulley 15 connected to the bowl rotary shaft 1C also has a magnitude different from the differential speed based on the difference in the outer diameter ratio, thereby causing the bowl rotary pulley 15 and the screw rotation to rotate. While being connected to the pulley 16 respectively, they are attached to a single drive shaft 10A of a single drive device 10 and are equal in rotation speed (rotation). Also between the bowl drive pulley 11 to be rotated with the screw driving pulley 12), a load acts to produce a speed difference.

  The load between the bowl drive pulley 11 and the screw drive pulley 12 is such that the axis X is applied to the shear pin 14 that connects the drive shaft 10A to which the bowl drive pulley 11 is fixed and the holder 12A to which the screw drive pulley 12 is fixed. Since it acts as a torsional moment, the shear pin 14 is broken by the load acting on the shear pin 14 before the load acting on the differential speed device 19 becomes large enough to cause damage to the differential speed device 19. By setting the strength of the shear pin 14, the shear pin 14 is broken before the differential speed device 19 is damaged, and the screw drive pulley 12 is rotated about the axis X with respect to the drive shaft 10A by the bearing 13. It will be in a state of relative rotation.

  Accordingly, at this time, the rotational driving force is not transmitted from the driving device 10 to the screw driving pulley 12, the screw rotating pulley 16, the differential speed device 19, and the screw rotating shaft 4D of the screw conveyor 4, and these rotate with the screw conveyor 4. Since the frictional force with the bowl 1 only causes the rotating bowl 1 to rotate together in a state where the differential speed is lowered, no load is applied to the differential speed device 19, and damage can be prevented beforehand. .

  For this reason, after that, for example, even when the reduction of the differential speed is detected by the protection means and the concentrator is stopped, the differential speed device 19 can be reliably protected, and the planetary gear as described above There is a situation in which the expensive differential speed device 19 which is a reduction gear (gearbox) incorporating a plurality of stages is forced to be replaced, or the operation of the concentrator must be stopped for a long time for repair. It is possible to prevent the occurrence. On the other hand, since the shear pin 14 is relatively inexpensive and easy to replace, the replacement of the broken shear pin 14 makes it possible to resume the concentration of the treatment object such as sludge at a low cost.

  Furthermore, in this embodiment, a constricted portion 14B is formed in the shear pin 14 so as to be positioned between the holder 12A of the screw drive pulley 12 and the drive shaft 10A of the drive device 10, and the constricted portion 14B Since the diameter is smaller than both ends 14A of the shear pin 14 fitted to the holder 12A and the drive shaft 10A, the shear pin 14 is broken when the load is applied.

  Therefore, by setting the outer diameter of the shear pin 14 in the constricted portion 14B appropriately according to the rotational driving force by the driving device 10 or the properties of the object to be processed such as sludge, the difference when an excessive load is applied. While preventing damage to the speed device 19 as described above, a situation where the shear pin 14 is broken and has to be frequently replaced even with a not-so-large load is prevented, and the screw conveyor 4 is rotationally driven reliably and efficiently. The force can be transmitted to facilitate a smooth concentration work. The constricted portion 14B has a U-shaped or V-shaped cross-section in order to adjust the ease of breaking the shear pin 14 in addition to the annular groove having a “U” -shaped cross section as in the present embodiment. Also good.

  Furthermore, in the present embodiment, the screw drive pulley 12 is attached to the drive shaft 10A via a bearing 13 such as a rolling bearing or a sliding bearing, and after the shear pin 14 is broken, the drive shaft 10A around the axis X of the drive shaft 10A. Thus, after the shear pin 14 is broken, the screw drive pulley 12 can be relatively rotated while being stably supported by the drive shaft 10A. Accordingly, even after the shear pin 14 is broken, the screw rotating pulley 16, the screw rotating shaft 4D, and the screw conveyor 4 can be smoothly rotated at a rotational speed substantially equal to that of the rotating bowl 1, thereby loading the differential speed device 19 with a load. It can prevent more reliably that it acts.

  In the present embodiment, as described above, the outer diameter ratio of the bowl rotating pulley 15 to the screw rotating pulley 16 is different from the outer diameter ratio of the bowl driving pulley 11 to the screw driving pulley 12. When the outer diameter ratio between the bowl driving pulley 11 and the screw driving pulley 12 is made larger than the outer diameter ratio between the rotating pulley 15 and the screw rotating pulley 16, and the differential speed between the rotating bowl 1 and the screw conveyor 4 decreases. In addition, a larger load can be applied to the shear pin 14, and the shear pin 14 can be surely broken before the excessive load is applied to the differential speed device 19 to release the load.

  However, even in the concentrator in which the outer diameter ratio of the bowl rotating pulley 15 to the screw rotating pulley 16 and the outer diameter ratio of the bowl driving pulley 11 to the screw driving pulley 12 are equal, for example, the screw rotating pulley 16 is a differential speed device. If the speed difference from the rotating bowl 1 is reduced, a load is applied to the bowl drive pulley 11 and the screw drive pulley 12 so that the speed difference is generated. Since the shear pin 14 is broken, the present invention can be applied to such a decanter type centrifugal concentrator.

DESCRIPTION OF SYMBOLS 1 Rotating bowl 1A Bowl main body 1C Bowl rotating shaft 2, 5, 13 Bearing 4 Screw conveyor 4A Screw conveyor main body 4D Screw rotating shaft 10 Drive apparatus 10A Drive shaft 11 Bowl drive pulley 12 Screw drive pulley 12A Screw drive pulley 12 holder 14 Shear pin 14B Constriction 15 Bowl rotation pulley 16 Screw rotation pulley 17, 18 V belt 19 Differential speed device 19
O Axis of rotating bowl 1 and screw conveyor 4 X Axis of driving shaft 10A of driving device 10

Claims (3)

  A decanter-type centrifuge having a screw conveyor that is rotationally driven coaxially with a speed difference from the rotating bowl inside a rotating bowl that is driven to rotate by a single drive device, the bowl rotating shaft of the rotating bowl And a screw rotating pulley and a screw rotating pulley are provided on the screw rotating shaft of the screw conveyor, and a bowl driving pulley connected to the bowl rotating pulley and the screw rotating pulley, respectively, on the driving shaft of the driving device. A screw drive pulley is provided, of which the screw drive pulley and the drive shaft are integrally rotatable via a shear pin, and are attached to each other around the axis of the drive shaft by breaking the shear pin. A decanter type centrifugal concentrator characterized by having   The decanter type centrifugal concentrator according to claim 1, wherein a constricted portion is formed between the screw drive pulley and the drive shaft in the shear pin.   2. The screw drive pulley is attached to the drive shaft via a bearing, and is rotatable relative to the drive shaft around the axis of the drive shaft by breaking the shear pin. Or the decanter type | mold centrifugal concentrator of Claim 2.

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