JP2001160485A - Induction heating roller device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent damage to an inner bearing due to stray potential induced by a roller body and a supporting rod. SOLUTION: An insulation mechanism for blocking electric current from a stray potential is set up in an inner roller bearing disposed between a support rod and a journal, in supporting a support rod that supports an induction heating mechanism arranged inside the roller body. Then an inductive brush for short- circuiting is installed between the supporting rod and the journal to short-circuit the inner bearing. By this arrangement an electric current does not flow and damage to the inner bearing is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an induction heating roller device, and more particularly to an induction heating roller device in which a support rod for supporting an induction heating mechanism is inserted into journals provided at both ends of a roller body.

[0002]

2. Description of the Related Art In this type of apparatus, journals are integrally connected to both ends of a roller body having a hollow inside, and the journal is rotatably supported on a machine base via bearings. , An induction heating mechanism having an induction coil is arranged, supported by a support rod, and supported by an internal bearing with respect to the journal, whereby the induction heating mechanism is suspended inside the roller body. There is known one that supports it.

FIG. 7 shows the construction of the roller body. Reference numeral 1 denotes a roller body having a hollow interior, which is integrally provided with a hollow journal 2 at both ends thereof, and the journal 2 is fixed by a bearing 3 on the outside thereof. Is rotatably supported by the machine base 4. When the journal 2 is rotated by an appropriate drive source (for example, a motor), the roller body 1 is rotated.

An induction heating mechanism 7 comprising an iron core 5 and an induction coil 6 wound around the core 5 is disposed inside the roller body 1, and both ends thereof are supported by support rods 8. The support rod 8 is supported on the journal 2 by an internal bearing 9 such as a rolling bearing, whereby the induction heating mechanism 7 is suspended inside the roller body 1. Reference numeral 10 denotes a sleeve provided as needed between the internal bearing 9 and the support rod 8, and reference numeral 11 denotes a lead wire of the induction coil 6, which passes through the inside of the support rod 8 and is led out from the end thereof, and is provided with an external excitation. Connected to an AC power supply.

In the above configuration, when an AC power is applied to the induction coil 6 to excite it, a current is induced on the peripheral wall of the roller body 1 and the current causes the roller body 1 to generate heat. By the way, in such a configuration, the internal bearing 9 is damaged in a short period of time, and the life thereof is significantly shortened. After examining the causes in various ways, the following were found.

In other words, the induction coil 6 may be divided into three parts, each of which may be star-connected to a three-phase AC power supply. However, according to such a connection configuration, both sides of the induction heating mechanism 7 (the shaft of the roller body 1). An alternating potential is generated on both sides along the center direction), and an alternating potential having a polarity opposite to the alternating potential is induced on both sides of the roller body 1 constituting a secondary circuit for the induction heating mechanism 6. I found out. The signs + and-in the circles in the figure indicate the polarity of the induced potential. The same applies to the case where the induction coil is delta-connected.

For example, an alternating potential having a polarity as shown in FIG. 1 may be generated on the support rods 8 on both sides of the induction heating mechanism 7, whereas, at the same time, the electric potential is applied to the journals 2 on both sides of the roller body 1. , An alternating potential having a polarity opposite to that of the potential induced on the support rod 8 is induced.

The generation of such an alternating potential is considered to be due to the following reasons. That is, as described above, the induction coil 6 is divided into three parts, which are arranged along the axial direction of the roller main body 1 as shown in the figure, and each divided induction coil 6 is connected to each phase of the three-phase AC power supply. In a star connection, no problem occurred when the power factor of each of the divided induction coils was all equally balanced.

However, if the power factor of the induction coil is unbalanced, the potential at the neutral point of the star connection changes,
As a result, an alternating potential (floating potential) is generated on both sides of the induction heating mechanism 7, and the roller body 1 forms a secondary circuit for the induction heating mechanism 7. It is considered that an alternating potential having a polarity opposite to the potential generated on both sides of the heating mechanism 7 is generated.

Although a large electric power is not generated by such an alternating potential, a current based on this potential is:
The current flows through the journal 2, the roller body 1, and the support rod 8 as shown by arrows in the drawing, and this current flows through the internal bearing 9. When a rolling bearing is used as the internal bearing 9, the rolling of the ball constituting the rolling bearing may break the oil film of lubricating oil or lubricating grease between the ball surface and the rolling surface. Therefore, the energization and disconnection are repeated between the ball surface and the rolling surface,
As a result, a spark is generated.

When such a spark is generated, the lubricating oil or lubricating grease is deteriorated, and the rolling surface of the internal bearing 9 is damaged, and the surface of the ball (or roller) is damaged and roughened. If the surface becomes rough, rolling as a bearing is hindered. In combination with the deterioration of lubricating oil and lubricating grease,
When the rolling becomes poor, the rolling resistance increases and heat is generated. As a result, it was found that the life of the internal bearing 9 was shortened.

[0012]

SUMMARY OF THE INVENTION An object of the present invention is to prevent the occurrence of damage to an internal bearing due to a floating potential induced on a roller body and a support rod.

[0013]

SUMMARY OF THE INVENTION The present invention is directed to a configuration in which a support rod for supporting an induction heating mechanism disposed inside a roller body is supported on a journal connected to the roller body via an internal bearing. An insulating mechanism is provided for preventing a current from flowing to an internal bearing interposed between the journal and the journal. Further, a conductive brush for short-circuiting is provided between the support rod and the journal so as to short-circuit the internal bearing.

Since the internal bearing supporting the support rod with respect to the roller body is electrically insulated from the support rod or the journal, a current caused by a floating potential induced in the roller body is not applied to the internal bearing. There is no flow, so that no sparks occur in the bearing, so that damage to the bearing is avoided.

Further, the present invention is characterized in that a slide bearing is used as the internal bearing. Since the sliding bearing does not use a ball like a rolling bearing, even if a current due to a floating potential flows, no spark is generated due to interruption of the oil film, and therefore no damage is caused by the spark. As the sliding bearing, a conductive bearing or a non-conductive bearing can be appropriately used. When a non-conductive material is used, the flow of current is interrupted, so that the generation of sparks is more reliably prevented.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIG. The same reference numerals as in FIG. 5 indicate the same or corresponding portions. FIG. 1 shows a detailed configuration when a sleeve 10 is used.
The internal bearing 9 made of a rolling bearing is fixed to the support rod 8 by the
And is fixed to the journal 2 by a retaining ring 17.

The example shown in the figure shows the case of insulation between the internal bearing 9 and the support rod 8, for which purpose the insulating coatings 17, 18 of ceramic coating are applied to the inner surface of the sleeve 10 and the outer surface facing the internal bearing 9. (See FIG. 2). Further, insulating rings 19 and 20 are provided on each end face of the sleeve 10, and insulating rings 21 and 22 are provided at positions facing the respective end faces of the internal bearing 9.

Thus, the sleeve 10, the internal bearing 9
Is mounted between the support rod 8 and the journal 2, the space between the internal bearing 9 and the support rod is
7 and 18 are electrically insulated by the insulating rings 17 to 22, and therefore, the current of the floating potential
The flow to the internal bearing 9 will be blocked.

FIG. 3 shows another embodiment of the present invention. This example shows a case where the sleeve 10 is not used, and the inner bearing 9 is used.
An insulating coating 23 is formed on the inner surface facing the outer surface of the support rod 8. A retaining ring 24 for fixing the internal bearing 9 to the support rod 8 is provided, and insulating rings 25 and 26 are provided on both end surfaces of the internal bearing 9.

In this way, the internal bearing 9 is connected to the support rod 8
When mounted between the bearing and the journal 2, the internal bearing 9
The insulating coating 23 and the insulating ring 2
5 and 26, and the flow of current due to the floating potential to the internal bearing 9 is prevented. 1 and 3, the insulation between the internal bearing 9 and the support rod 8 is insulated. Alternatively, the insulation between the internal bearing 9 and the journal 2 may be provided. .

FIG. 4 shows still another embodiment of the present invention.
In this structure, the internal bearing 9 is short-circuited so that the current caused by the floating potential is bypassed by a conductive brush. Is in contact with the outer peripheral surface of the support rod 8. According to this, the current due to the floating potential flows between the journal 2 and the support rod 8 via the conductive brush 27 and does not flow to the internal bearing 9.

Each of the above embodiments is an example in which a rolling bearing using a ball is used as the internal bearing 9.
According to the rolling bearing using the ball, since the spark is generated by the rolling of the ball as described above, if a bearing that does not use the ball and the lubricating oil, that is, if the sliding bearing is used as the internal bearing, Damage to the bearing due to the generation of spark will be avoided.

The embodiment shown in FIGS. 5 and 6 shows a configuration in which a sliding bearing 30 is used as an internal bearing based on the above-mentioned purpose. Slide bearing 3 in this case
If it is set to 0, it is considered that spark does not occur even if a current flows here, so that it may be conductive. However, if this is made non-conductive, the flow of current is interrupted, so that the generation of sparks is more reliably prevented. FIG. 5 shows each configuration when the sleeve 10 is used, and FIG. 6 shows each configuration when the sleeve 10 is not used.

[0024]

As described above, according to the present invention, a support rod for supporting an induction heating mechanism disposed inside a roller body is supported by a journal connected to the roller body via an internal bearing. Since the current flow due to the floating potential to the internal bearing interposed between the support rod and the journal was prevented, deterioration due to damage to the internal bearing was prevented, or a sliding bearing was used as the internal bearing. This has the effect of enabling the internal bearing to have a longer service life.

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of a sleeve in FIG.

FIG. 3 is a partial sectional view showing another embodiment of the present invention.

FIG. 4 is a partial sectional view showing still another embodiment of the present invention.

FIG. 5 is a partial sectional view showing still another embodiment of the present invention.

FIG. 6 is a partial sectional view showing still another embodiment of the present invention.

FIG. 7 is a sectional view of the induction heating roller device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roller main body 2 Journal 7 Induction heating mechanism 8 Support rod 9 Inner bearing 10 Sleeve 17 Insulation coating 18 Insulation coating 19-22 Insulation ring 23 Insulation coating 25-26 Insulation ring 27 Conductive brush 30 Slide bearing

[Procedure amendment]

[Submission date] December 14, 1999 (1999.12.
14)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

In other words, the induction coil 6 may be divided into three parts, each of which may be star-connected to a three-phase AC power supply. However, according to such a connection configuration, both sides of the induction heating mechanism 7 (the shaft of the roller body 1). An alternating potential is generated on both sides along the center direction), and an alternating potential having a polarity opposite to the alternating potential is induced on both sides of the roller body 1 constituting a secondary circuit for the induction heating mechanism 7 . I found out. The signs + and-in the circles in the figure indicate the polarity of the induced potential. The same applies to the case where the induction coil is delta-connected.

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction contents]

[0007] For example there are times when the polarity of the alternating voltage, as shown in figure support rod 8 on each side of the induction heating mechanism 7 is generated, whereas di catcher Naru at the same time with respect thereto on each side of the roller body 1 2, an alternating potential having a polarity opposite to that of the potential induced in the support rod 8 is induced.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

Thus, the sleeve 10, the internal bearing 9
Is mounted between the support rod 8 and the journal 2, the space between the internal bearing 9 and the support rod is
7 and 18 are electrically insulated by the insulating rings 19 to 22, so that the current due to the floating potential is
The flow to the internal bearing 9 will be blocked.

[Procedure amendment 4]

[Document name to be amended] Drawing

[Correction target item name] Fig. 5

[Correction method] Change

[Correction contents]

FIG. 5

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Claims (3)

[Claims] 1. An induction motor having an induction coil which is integrally disposed at both ends of a roller body having a hollow interior and which is disposed inside the roller body and which is excited by a three-phase AC power supply. In an induction heating roller device in which a support rod supporting a heat generating mechanism is inserted through the journal and the support rod is supported by the internal bearing with respect to the journal, between the support rod and the internal bearing,
Alternatively, an induction heating roller device provided with an insulating mechanism between the journal and the internal bearing for interrupting a current caused by a floating potential flowing through the internal bearing. 2. An induction coil having an induction coil which is arranged inside the roller main body and integrally arranged at both ends of a roller main body having a hollow inside, and is arranged inside the roller main body and excited by a three-phase AC power supply. In an induction heating roller device in which a support rod for supporting a heat generating mechanism is inserted through the journal and the support rod is supported by the internal bearing with respect to the journal, the internal bearing is provided between the support rod and the journal. An induction heating roller device comprising a conductive brush for bypassing a current caused by a floating potential flowing through the roller. 3. An induction coil having an induction coil which is integrally disposed at both ends of a roller body having a hollow interior and which is disposed inside the roller body and which is excited by a three-phase AC power supply. In an induction heating roller device in which a support rod for supporting a heat generating mechanism is inserted through the journal and the support rod is supported by the internal bearing with respect to the journal, the internal bearing may be a conductive or non-conductive sliding bearing. An induction heating roller device constituted by: