JP2002172347A - Magnetic separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately recover the metal (magnetic material) of instruments, which have structures hard in separating a winding, an iron plate, a resin outer frame or the like, like a motor for a household electric product or the like by a simple device. SOLUTION: Magnetic 11c-15c, comprising non-magnetic pipes 11a-15a and rotors 11b-15b arranged in the non-magnetic pipes in a freely rotatable manner through a slight gap, are provided over at least two or more stages and the respective adjacent magnet rollers are connected by guide plates 11d-14d comprising a non-magnetic material. The rotors 11b-15b are constituted so that a part in the circumferential direction of them is magnet parts 11e-15e and the other parts of them are non-magnet parts 11f-15f.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention mainly relates to the recovery of metal (magnetic material) from equipment having a structure in which windings, iron plates, resin outer frames and the like are difficult to separate, such as motors used in home electric appliances. Related to equipment used in the recycling business.

[0002]

2. Description of the Related Art As a conventional technique, there is a magnetic separator disclosed in Japanese Unexamined Patent Publication No. 300230/1999. This will be described with reference to FIG.

[0003] The magnetic fan 7 and the non-magnetic sawdust 8 thrown in from the spout 6a by the turbo fan 1 are blown in the horizontal direction, collide with the inner wall 6b of the apparatus, and reach the upper magnet roller 2. I do. Magnet rollers 2, 3
, Each having a built-in magnet 2 a, 3 a fixed to the top and bottom, respectively, and rotating in the same arrow direction. The rotation center of the lower magnet roller 3 is shifted from the upper magnet roller 2 by an appropriate distance in the direction in which the magnetic material falls.

[0004] The magnetic fragments 7 reaching the upper magnet roller 2 are conveyed to the lower end by the rotation of the magnet roller 2. On the other hand, the non-magnetic material fragments 8 fall along the surface of the magnet roller due to gravity, and fall into the container 5 for non-magnetic material fragments.

On the other hand, the magnetic fragments 7 move to the lower magnet roller 3 and move in accordance with the rotation of the lower magnet roller 3. In this case, when the magnetic fragments 7 and the non-magnetic fragments 8 are entangled with each other, and when the magnetic fragments 7 are sucked by the upper magnet roller 2 with the non-magnetic fragments 8 interposed therebetween, the upper magnet Non-magnetic fragments 8 do not fall from the roller 2. However, when the magnetic debris 7 is attracted to the lower magnet roller 3, the non-magnetic debris 8 is outside the magnetic debris 7 with respect to the lower magnet roller 3. Fall. The magnetic debris 7 moves according to the rotation of the lower magnet roller 3, and when the magnet 3a is cut off at the lowest point, the magnetic debris 7
Loses the attraction to the magnet roller 3 and falls into the magnetic material debris container 4.

[0006]

According to the above construction, it is possible to sort a magnetic material and a non-magnetic material with high accuracy. However, since the outer cylinder rotates, a thin non-magnetic pipe is used as the rotating outer cylinder. Must be rotatably arranged, which complicates the structure. Usually, a method is employed in which a housing is formed at both ends of a rotary outer cylinder, bearings are installed, and the rotary outer cylinder is rotatably fixed to a shaft. At this time, since the precision of the housing affects the precision of the gap between the magnet and the magnet roller, it is necessary to increase the gap, and the magnetic force acting on the magnetic debris on the rotating outer cylinder of the magnet roller is weakened. To increase the size of the magnet.

Further, since the permanent magnet is fixed, a scraper (claw) is required, and the magnetic fragments are forcibly scraped, so that the sorting accuracy may be reduced. Further, even if the magnetic material fragments hit the scraper, they may rebound and scatter, and a phenomenon that the magnetic particles cannot be attracted by the magnet of the magnet roller may occur. Therefore, mixing of magnetic debris into the container for non-magnetic material debris or mixing of non-magnetic debris into the container for magnetic debris occurs, and the sorting accuracy is reduced.

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a magnet comprising a non-magnetic pipe and a rotor rotatably disposed inside the non-magnetic pipe via a small gap. At least two or more rollers are provided, and adjacent magnet rollers are connected by a guide plate made of a non-magnetic material. A part of the rotor is a magnet part in the circumferential direction, and the other part is a non-magnetic material, a non-magnetized magnet, or a sufficiently large air gap. According to this configuration, since the configuration is easy, the size can be reduced, and the accuracy of sorting magnetic and non-magnetic materials is improved.
In addition, since only the magnetic fragments move on the non-magnetic pipe by the attraction force with the magnet, the sorting accuracy is improved.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is characterized in that a magnet roller comprising a non-magnetic pipe and a rotor rotatably disposed inside the non-magnetic pipe with a small gap therebetween is provided at least by two or more. A magnetic separator in which a plurality of stages are provided and each adjacent magnet roller is connected by a guide plate made of a non-magnetic material, wherein the rotor is partially a magnet part in a circumferential direction and the other part Is a non-magnetic material or a non-magnetized magnet or a sufficiently large air gap (hereinafter, referred to as a non-magnet part),
Since the configuration is easy, the size can be reduced, and the accuracy of sorting magnetic and non-magnetic materials can be improved.

According to a second aspect of the present invention, there is provided the magnetic separator according to the first aspect, wherein the rotors have a mechanism for rotating in the same direction at the same angular velocity. Therefore, the sorting accuracy is improved.

According to a third aspect of the present invention, there is provided the magnetic separator according to the second aspect, wherein the rotor is a pulley connected to the shaft end of the rotor as a mechanism for rotating the rotor in the same direction at the same angular velocity. Therefore, it can be driven by one electric motor.

According to a fourth aspect of the present invention, when n is an integer of 1 or more and the number of stages of the magnet roller is -1 or less, the magnet roller of the nth stage and the magnet roller of the (n + 1) th stage are connected for all n. Near the guide plate, n
4. The magnet roller according to claim 1, wherein, when the magnet roller changes from a magnet portion to a non-magnet portion in the magnet roller of the stage, the magnet roller of the (n + 1) th stage functions as a magnet portion. 5. In the magnetic separator, the magnetic fragments can be transported with high precision without leaving the magnetic fragments in the preceding magnetic separator, and the sorting accuracy is improved.

According to a fifth aspect of the present invention, in the magnetic separator according to any one of the first to fourth aspects, the magnet portions facing each other via the guide plate are opposite electrodes. Accordingly, the accuracy of sorting magnetic and non-magnetic materials is improved.

According to a sixth aspect of the present invention, in the magnet roller of the last stage, a stopper for stopping magnetic debris is provided. The magnetic debris can be collected in the magnetic debris container without the magnetic debris remaining on the last-stage magnet roller or returning to the previous-stage magnet roller.

According to a seventh aspect of the present invention, a container for non-magnetic material debris is installed at least at a place where the non-magnetic material debris that has moved on the magnet roller falls due to gravity, and the non-magnetic material debris container is located near the end point of the last stage magnet roller. 7. The magnetic separator according to claim 6, wherein a container for magnetic material fragments is provided, wherein the sorted magnetic material fragments and non-magnetic material fragments can be collected accurately and efficiently.

According to an eighth aspect of the invention, the first-stage and second-stage magnet rollers are arranged substantially vertically, and the last-stage first-stage magnet roller and the last-stage magnet roller are at least rotated. The magnetic separator according to any one of claims 1 to 7, wherein the magnetic fragments and the non-magnetic fragments are dropped in the same direction, wherein the magnetic fragments and the non-magnetic fragments are disposed in a forward direction of rotation of the child. Can be prevented, and sorting can be performed with high accuracy.

According to a ninth aspect of the present invention, a crushing mechanism for crushing a device such as an electric motor into a mixture of magnetic and non-magnetic fragments is provided on the first-stage magnet roller. The magnetic separator according to any one of claims 1 to 8, wherein a device to be recycled in a sufficiently crushed state can be put in, and the sorting accuracy is improved.

According to a tenth aspect of the present invention, in the magnetic separator according to any one of the first to ninth aspects, the magnet portion of the magnet roller is a permanent magnet. And the configuration can be simplified.

The invention according to claim 11 is characterized in that the magnet portion of the magnet roller is an electromagnet which becomes a magnet when a current flows through a winding provided on the iron core. In the magnetic separator according to any one of the above, the suction force can be freely adjusted, and the configuration can be easily performed without requiring a mechanical rotation mechanism.

According to a twelfth aspect of the present invention, at least two or more stages of a non-magnetic pipe and a magnet roller disposed inside the non-magnetic pipe with a gap between the non-magnetic pipe being zero are provided. A magnetic separator in which adjacent magnet rollers are connected by a guide plate made of a non-magnetic material, wherein a magnet portion of the magnet roller is an electromagnet that becomes a magnet when a current flows through a winding provided on an iron core. This is a magnetic separator characterized by the fact that the attractive force of the magnet can be increased and the strength of the non-magnetic pipe can be secured.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of a magnetic separator according to one embodiment of the present invention.

FIG. 2 is a partial perspective view of a magnetic separator according to one embodiment of the present invention.

FIG. 3 is a view for explaining the manner of selection of the magnetic separator in one embodiment of the present invention.

The magnetic separator comprises non-magnetic pipes 11a and 12a.
a, 13a, 14a, and 15a, and magnet rollers 11c, 12c, 13c, and 14c including rotors 11b, 12b, 13b, 14b, and 15b rotatably disposed inside the nonmagnetic pipe with a small gap therebetween. , 15c
Are provided in five stages, and a guide plate 11d, 12d, 13 made of a non-magnetic material is provided between adjacent magnet rollers.
d and 14d.

Also, a wall 27 connecting the outer wall and the first-stage magnet roller is provided so that the fragments input from the input port 20 do not enter the inside of the magnetic separator (the side opposite to the side where the fragments are transported). Is provided.

The rotors 11b, 12b, 13b, 14b,
Numeral 15b is a magnet part 11e, 12e, 13e, 14e, 15e composed of a permanent magnet partially magnetized in the circumferential direction, and the other part is a non-magnetic material or a non-magnetized magnet or a sufficiently large magnet. Air gap (hereinafter referred to as non-magnet part) 11
f, 12f, 13f, 14f, and 15f. In the case of this embodiment, a non-magnetic material such as aluminum or resin is arranged, and is fixed to the permanent magnet by covering with an adhesive or a stainless steel pipe.

The rotors 11b, 12b, 13b, 14b,
15b has shafts 11g, 12g, and 13g, and is rotatably held. Further, since the shafts of the adjacent rotors are connected by the pulley 16, all the rotors 11b,
12b, 13b, 14b and 15b rotate in the same direction at the same angular velocity. Further, the electric motor may be connected to only one of the rotor shafts. Here, the shaft between adjacent rotors may be a gear or the like instead of a pulley. It is sufficient that all the rotors rotate in the same direction at the same angular velocity.

Next, the sorting process of the magnetic separator will be described.

A mixture of the magnetic fragments 7 and the non-magnetic fragments 8 that have undergone the crushing step is carried to the inlet 20. In the case of the present embodiment, the sheet is transported by the belt conveyor 21.

The magnetic material fragments 7 and the non-magnetic material fragments 8 transported by the belt conveyor 21 and input from the input port 20 are
As shown in FIG. 3A, the first-stage magnet roller 11c
To fall. Here, the non-magnetic material fragments 8a fall as they are by gravity and are collected in the non-magnetic material fragment container 22. On the other hand, the magnetic material fragments 7 are attracted to the magnet portion 11e of the first-stage magnet roller 11c. Here, the non-magnetic material fragments 8b
Does not fall due to gravity when it is between the magnetic material fragment 7 and the magnet roller 11c, but when the rotor 11b rotates and the magnet 11e exceeds the guide plate 11d,
As shown in FIG. 3B, the magnetic fragments 7 are attracted to the magnet portion 12e of the second-stage magnet roller 12c, and the non-magnetic fragments 8b are outside the magnetic fragments 7 with respect to the magnet portion 12e. . Therefore, as shown in FIG. 3C, when the rotor 12b rotates, the non-magnetic material fragments 8b fall by gravity. This is repeated, and as shown in FIG.
The fifth-stage magnet roller 15c is stopped by a stopper 24 provided on the opposite side of the guide plate 14d, and when the stopper 24 passes the magnet portion 15e, the suction force is lost and the container 23 for magnetic debris 23 To fall. here,
n is 1 or more, and the magnet rollers 11c, 12c, 13
Assuming that the number of stages of c, 14c, and 15c is an integer equal to or less than −1 (4 in this embodiment), for all n, in the vicinity of the guide plate connecting the n-th stage magnet roller and the (n + 1) th stage magnet roller, In the n-th stage magnet roller, when the magnet portion changes from a magnet portion to a non-magnet portion, the magnet portion may be arranged so that the (n + 1) th stage magnet roller becomes a magnet portion. Thereby, the guide plates 11d, 12d, 13
In the vicinity of d and 14d, the magnetic debris can smoothly move to the next-stage magnet roller. Note that n
The surface where the magnetic debris attracted by the magnet roller at the stage is in contact with the magnet roller becomes a magnetic pole (tentatively N pole) of the magnet roller and a counter electrode (S pole). Accordingly, the side of the magnetic debris that is attracted to the (n + 1) th stage magnet roller has a further opposite pole (N pole), that is, the same magnetic pole as the nth stage magnet roller. In order to smoothly select and attract the magnetic debris to the (n + 1) th stage magnet roller as the next stage, the magnetic pole of the (n + 1) th stage magnet roller may be a magnetic pole (S pole) which is a counter electrode thereof. For the above reasons, if the magnetic roller is arranged alternately so that the magnetic poles of the magnet roller facing each other via the guide plate are the counter electrodes, magnetic and non-magnetic fragments can be more smoothly and accurately selected. Can be.

The first-stage and second-stage magnet rollers are arranged substantially vertically, so that when the magnetic debris 7 is thrown in from the slot 20, the first-stage magnet roller 11 c is moved to the position shown in FIG. As shown in FIG.
When f appears, the first-stage magnet roller 11c
Although the magnetic debris 7 is not attracted and falls by gravity, the magnetic debris 7 is attracted to the second-stage magnet roller 12c because the second-stage magnet roller 12c is the magnet part 12e. Therefore, the second-stage magnet roller 12c is a lower portion in the vertical direction with respect to the first-stage magnet roller 11c, and may be slightly arranged on the side of the input port 20. Thus, the rotors 11b, 12b, 13b, 14
b, 15b, magnet parts 11e, 12e, 13e, 1
The proportion of 4e and 15e needs to be 50% or more. It is preferable that about two-thirds to about three-quarters have a magnet part. Here, three tile-shaped permanent magnets having a central angle of 90 ° are attached to the surface of a cylindrical rotor core made of a material having a high magnetic permeability such as iron so as to be in contact with each other. Such a rotor can be made. At this time, it is preferable that a space of 90 ° where there is no permanent magnet is a gap or a spacer such as a resin is provided.

Further, a fourth-stage magnet roller 14c
By disposing the magnetic roller 15c of the fifth stage at least in the forward direction of the rotation of the rotor, the magnetic fragments 7 are reliably separated from the non-magnetic fragments and dropped into the magnetic fragment container 23 to be collected. It is possible to

The non-magnetic pipes 11a, 12a, 13
a, 14a, and 15a, portions 11h, 12h, 13h, 14h, and 1h through which magnetic fragments and non-magnetic fragments do not pass.
The thickness of 5h may be thicker, and the magnetic fragments of the non-magnetic pipe and the portions 11h, 12h, 1h through which the non-magnetic fragments do not pass.
3h, 14h, 15h and guide plates 11d, 12d, 13
If d, 14d and the stopper 24 are integrally formed as a rigid body, the strength is increased. Furthermore, since the magnetic fragments move on the outer peripheral surface of the non-magnetic pipe, it is possible to prevent the magnetic fragments from moving while holding the non-magnetic fragments.

The rotating mechanism is simple, and the rotor can be fixed by providing a through hole at the center of rotation, press-fitting the shaft, and holding the shaft by bearings. Therefore, the device can be downsized. Therefore, the magnetic separator according to the present embodiment can be installed under a crushing mechanism that crushes a device such as an electric motor into a mixture of magnetic fragments and non-magnetic fragments. The crushing mechanism is disclosed in Japanese Patent Application No. 2000-18893 as shown in FIG.
Suitable are those as disclosed in the third separator. The rotating body 31 is a disk-shaped thin plate that is rotatably supported by an outer frame 36 via a bearing 34 and that is fixed to a shaft 33 that rotates at a high speed by external power, and a plurality of radially arranged outer peripheral portions. It has a blade 32. The drop adjusting shelf 37 is a ring-shaped structure having a wedge-shaped cross section, and is attached to the inner wall of the outer frame 36, and has a function of guiding the dropped workpiece 35 to the inner diameter side of the rotating body 31. The loading port 38 is provided on the upper surface of the outer frame 36, and the workpiece 35 loaded from the loading port 38 falls naturally by gravity. At this time, the uppermost drop adjusting shelf 37 is the object 3 to be dropped on the outer peripheral side of the rotating body.
5 is guided inside the rotating body 31 by its wedge shape. The object to be processed 35 that has fallen on the rotating body 31 is urged toward the outer diameter direction by centrifugal force and collides with the inner wall of the outer frame 36. Also,
Free fall. A part of the processing object 35 is directly hit by the blade 32, and is urged in a direction perpendicular to the hitting surface of the blade 32 to fly out and collide with the inner wall of the outer frame 36. In this way, the object 35 is decomposed into a mixture of magnetic fragments and magnetic fragments, and if these are collected and transported to the inlet 20 of the magnetic separator in this embodiment as they are, crushing is performed. Up to magnetic separation can be realized by one apparatus.

The rotors 11b, 12b, 13b, 1
4b and 15b are rotated at about 1 rotation / second,
What is necessary is just to change according to an input amount and the magnitude | size of an input material.

Here, the magnet portion is not a permanent magnet,
It can also be an electromagnet. At this time, the rotor is
An electromagnet which becomes a magnet when a current flows through a winding provided on the iron core, the magnet portion may be formed by applying a current to the winding, and the non-magnet portion may be formed by not passing a current through the winding. . At this time, the iron core may have salient poles on the outer peripheral side, and the salient poles may be wound. At this time, no air gap is required between the iron core and the non-magnetic pipe, and if they are closely attached, the magnetic force can be further increased. Further, since a rotating mechanism is not required, the structure is further simplified. Further, the magnetic force can be adjusted by changing the current value.

In the above description, iron is a typical magnetic substance, and in particular, an electromagnetic steel sheet used for an iron core of a motor can be mentioned. On the other hand, as a non-magnetic material,
Copper, resin, aluminum, etc.

It should be noted that the present invention is not limited to only the above-described embodiment, and for example, the arrangement and the number of steps of the magnet roller can be changed. That is, various modifications are possible in accordance with the gist of the present invention, and these are not excluded from the claims.

[0040]

As is clear from the description of the above embodiment,
According to the first aspect of the present invention, since the configuration is easy, the size can be reduced, and the accuracy of sorting magnetic and non-magnetic materials can be improved.

According to the second aspect of the present invention, the movement of the magnetic fragments is in one direction, and the sorting accuracy is improved.

According to the third aspect of the present invention, the drive can be performed by one electric motor, the configuration of the magnetic separator is easy, and the size can be reduced.

According to the fourth aspect of the invention, the magnetic debris can be transported with high accuracy without leaving the magnetic debris in the preceding magnetic separator, and the sorting accuracy is improved.

According to the fifth aspect of the invention, the magnetic debris is smoothly attracted to the next-stage magnet roller without being attracted to the next-stage magnet roller due to the repulsive force of the magnetic pole and without being flied off. And the sorting accuracy is improved.

According to the sixth aspect of the present invention, the magnetic fragments can be collected in the container for the magnetic fragments without the magnetic fragments remaining on the last-stage magnet roller or returning to the preceding magnet roller. .

According to the seventh aspect of the invention, the selected magnetic and non-magnetic fragments can be accurately and efficiently recovered.

According to the eighth aspect of the present invention, it is possible to prevent the magnetic fragments and the non-magnetic fragments from dropping at the same time, and it is possible to accurately sort the fragments.

According to the ninth aspect of the present invention, a device to be recycled can be put in a sufficiently crushed state, and the sorting accuracy is improved.

According to the tenth aspect, the suction force can be increased, and the configuration can be simplified.

According to the eleventh aspect of the present invention, the suction force can be freely adjusted, and the structure can be simplified without the need for a mechanical rotation mechanism.

According to the twelfth aspect, the attraction force of the magnet can be increased, and the strength of the non-magnetic pipe can be secured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a magnetic separator according to an embodiment of the present invention.

FIG. 2 is a partial perspective view of a magnetic separator according to one embodiment of the present invention.

3 (a) to 3 (f) are diagrams showing a sorting process of a magnetic separator in one embodiment of the present invention.

FIG. 4 is a sectional view of a separator installed in a magnetic separator in one embodiment of the present invention.

FIG. 5 is a sectional view of a conventional magnetic separator.

[Explanation of symbols]

11a, 12a, 13a, 14a, 15a Non-magnetic pipe 11b, 12b, 13b, 14b, 15b Rotor 11c, 12c, 13c, 14c, 15c Magnet roller 11d, 12d, 13d, 14d Guide plate 11e, 12e, 13e, 14e , 15e Magnet part 11f, 12f, 13f, 14f, 15f Non-magnet part 11g, 12g, 13g Shaft 16 Pulley 20 Input port 22 Container for non-magnetic debris 23 Container for magnetic debris 24 Stopper

Claims (12)

[Claims] 1. A magnet roller comprising at least two stages of a non-magnetic pipe and a rotor rotatably disposed inside the non-magnetic pipe with a small gap therebetween, between each adjacent magnet roller. A magnetic separator connected by a guide plate made of a non-magnetic material,
The rotor is characterized in that a part is a magnet part in the circumferential direction, and the other part is a non-magnetic material or a non-magnetized magnet or a sufficiently large air gap (hereinafter referred to as a non-magnet part). And a magnetic separator. 2. The magnetic separator according to claim 1, wherein all the rotors have a mechanism for rotating in the same direction at the same angular velocity. 3. The magnetic separator according to claim 2, wherein the rotors are pulleys connected to shaft ends of the rotors as mechanisms for rotating the rotors in the same direction at the same angular velocity. 4. n is 1 or more, the number of stages of the magnet roller−
When an integer of 1 or less, for all n, in the vicinity of the guide plate connecting the n-th stage magnet roller and the (n + 1) -th stage magnet roller, when the n-th stage magnet roller changes from a magnet part to a non-magnet part 4. The magnetic separator according to claim 1, wherein the n + 1-th stage magnet roller is a magnet unit. 5. The magnetic separator according to claim 1, wherein the magnet portions facing each other via the guide plate are opposite poles. 6. The magnetic separator according to claim 1, wherein a stopper for stopping magnetic debris is provided on the last-stage magnet roller. 7. A container for a non-magnetic material debris is installed at least at a place where the non-magnetic material debris moved on the magnet roller falls due to gravity, and the container for a magnetic material debris is placed below the vicinity of the end point of the last-stage magnet roller. The magnetic separator according to claim 6, wherein the magnetic separator is installed. 8. The magnet roller of the first and second stages,
8. The magnet roller according to claim 1, wherein the magnet roller is arranged in a substantially vertical direction, and the last-first-stage magnet roller and the last-stage magnet roller are arranged at least in a forward direction of rotation of the rotor. A magnetic separator according to any one of the preceding claims. 9. A crushing mechanism for crushing a device such as an electric motor into a mixture of magnetic fragments and non-magnetic fragments on a first-stage magnet roller. 8. The magnetic separator according to any one of items 8 to 8. 10. The magnetic separator according to claim 1, wherein the magnet portion of the magnet roller is a permanent magnet. 11. The magnet unit according to claim 1, wherein the magnet portion of the magnet roller is an electromagnet which becomes a magnet when a current flows through a winding provided on the iron core. Magnetic separator. 12. A non-magnetic pipe, and at least two or more stages of magnet rollers disposed inside the non-magnetic pipe with a gap between the non-magnetic pipe being zero, and a gap between each adjacent magnet roller is provided. A magnetic separator connected by a guide plate made of a magnetic material, wherein the magnet portion of the magnet roller is an electromagnet which becomes a magnet when a current flows through a winding provided on an iron core. Machine.