DE202013007840U1 - impression roller - Google Patents

Abstract

Impression roller of a rotary printing machine with
A cylinder (2) which is more or less electrically conductive in at least one region (4),
- Means for rotatable bearing (6) of the cylinder about its cylinder axis and
At least one device for supplying an electrical voltage (9) to the electrically conductive region (4),
- An electrically conductive, the cylinder (2) coaxial shaft (5) or axis and
- Has at least one to the cylinder (2) coaxial sliding ring (12, 14, 29) of electrically conductive and flexible material which is slidably mounted on the shaft (5) or axis,
- Wherein either the electrically conductive shaft (5) rotatably connected to the cylinder (2) and is electrically connected to the electrically conductive portion of the cylinder (2), the sliding ring (12, 14, 29) is arranged stationary and with an electrical Power supply is connectable,
- Or the slide ring (12, 14, 29) rotatably connected to the cylinder (2) and is electrically connected to the electrically conductive region (4) and the axis is arranged stationary and can be connected to an electrical power supply.

Description

The invention relates to a impression roller of a rotary printing press.

During rotary printing, the web-shaped or sheet-shaped printing material (eg paper, cardboard or plastic films) is passed at high speed between a pressure roller and a impression roller. Particularly high speeds are achieved in commercial printing. The printing cylinder picks up ink from a paint pan in cells in its surface. The surplus is usually shaken off. In order to transfer the ink from the wells of the printing cylinder lying electrically to the greatest possible extent onto the printing material, a more or less electrically conductive region of a cylindrical impression roller with a rubber-elastic outer layer is supplied with a high voltage. The electrically conductive region is z. Example, to a semiconductor layer, which is applied to the circumference of a solid or hollow cylinder body. As a result, an electric field forms between the electrically conductive region and the printing cylinder, which exerts a force on the ink in the cells, which intensifies the transition of the ink to the printing material and increases the print quality.

It is known to supply the impression roller with the electrical charge via a needle electrode (also called a "spray electrode"), which is spaced from the impression roller by an air gap. Furthermore, it is known to supply the impression roller with the electrical voltage via laterally arranged electrodes, brush grinding contacts or via the bearings.

From the EP 0 556 463 B1 For example, there is known an axleed impression roller having a limited conductive coating over a steel jacket. The covering is supplied with the electrical charges via the axle, a ball bearing between the axle and the steel jacket and the steel jacket. Furthermore, from this publication, a impression roller with a shaft and a limited conductive coating on a steel jacket known. The covering the electric charges are supplied via a arranged on the front side of the shaft ball bearing, the shaft and the steel shell.

The voltage supply via electrodes and brush grinding contacts is unreliable because of soiling and wear. The supply of ball bearings can be affected by the wear of the bearings, which can be accelerated by the supply of voltage.

From the EP 1 780 011 A1 For example, a pressure roller with a more reliable device for supplying an electrical voltage is known, which has a rotor connected to the cylinder and concentric with the cylinder axis and a stator spaced from the rotor concentric with the cylinder axis and a cavity between rotor and stator. A rotor electrode facing the cavity is connected to the electrically conductive region of the cylinder, and a stator electrode facing the cavity can be connected to an electrical power supply. In the cavity, an electrically conductive fluid is arranged. Means for preventing leakage of the electrically conductive fluid from the cavity are present. According to one embodiment, this is a sealing element which laterally delimits the cavity between the stator and the rotor, which may be designed in particular as a simmer ring.

The DE 20 2007 002 726 U1 describes a further impression roller with a more reliable means for supplying an electrical voltage, which identifies an electrically conductive contact element in a device for guiding and a spring element for pressing the electrically conductive contact element against the circumference of the shaft or axis. According to one embodiment, the contact element is a contact pin. According to a further embodiment, the means for supplying an electrical voltage comprises a stator, a rotor, a cavity between the stator and the rotor, in which the means for guiding with the contact element is arranged, an electrically conductive fluid in the cavity and means for preventing the outflow of the electrically conductive fluid from the cavity. The electrical voltage is transmitted from the electrically conductive contact element to the shaft or from the axis to the electrically conductive contact element. In addition, a voltage transfer between the stator and the rotor can be effected by the electrically conductive fluid. This is particularly advantageous when the electrically conductive contact element fails. Conversely, the electrically conductive contact element can transmit the electrical voltage when the voltage transmission is interrupted by the electrically conductive fluid.

Based on this, the present invention seeks to provide a impression roller with a device for supplying an electrical voltage, which works reliably with little effort.

The object is achieved by a impression roller with the features of claim 1.

• – einen Zylinder, der zumindest in einem Bereich mehr oder weniger elektrisch leitfähig ist,
• – Mittel zum drehbaren Lager des Zylinders um seine Zylinderachse und
• – mindestens eine Einrichtung zum Zuführen einer elektrischen Spannung an den elektrisch leitfähigen Bereich,
• – die eine elektrisch leitfähige, zum Zylinder koaxiale Welle oder Achse und
• – mindestens einen zum Zylinder koaxialen Gleitring aus elektrisch leitfähigem sowie flexiblem Material aufweist, der auf der Welle oder Achse gleitend aufsitzt,
• – wobei die elektrisch leitfähige Welle drehfest mit dem Zylinder verbunden ist und elektrisch mit dem elektrisch leitfähigen Bereich des Zylinders verbunden ist, der Gleitring ortsfest angeordnet ist und mit einer elektrischen Spannungsversorgung verbindbar ist
• – oder der Gleitring drehfest mit dem Zylinder verbunden ist und elektrisch mit dem elektrisch leitfähigen Bereich verbunden ist und die Achse ortsfest angeordnet ist und mit einer elektrischen Spannungsversorgung verbindbar ist.

The impression roller according to the invention has a rotary printing press

• A cylinder which is more or less electrically conductive in at least one region,
• - Means for rotatably supporting the cylinder about its cylinder axis and
• At least one device for supplying an electrical voltage to the electrically conductive region,
• - An electrically conductive, coaxial to the cylinder shaft or axis and
• - Has at least one coaxial to the cylinder sliding ring of electrically conductive and flexible material which is slidably seated on the shaft or axle,
• - Wherein the electrically conductive shaft is rotatably connected to the cylinder and is electrically connected to the electrically conductive region of the cylinder, the seal ring is arranged stationary and can be connected to an electrical power supply
• - Or the slip ring is rotatably connected to the cylinder and is electrically connected to the electrically conductive region and the axis is arranged stationary and can be connected to an electrical power supply.

In the impression roller according to the invention, the electrical voltage is supplied via at least one means for supplying an electrical voltage having an electrically conductive, coaxial to the cylinder shaft or axis and at least one coaxial to the cylinder sliding ring of electrically conductive and flexible material on the shaft or Axis slidably seated. If the impression roller has a shaft, this is non-rotatably connected to the cylinder and electrically connected to the electrically conductive region of the cylinder. The sliding ring is arranged stationary in this variant of the invention and connectable to an electrical power supply. The electrical voltage passes from the sliding ring on the rotating shaft and from the shaft to the electrically conductive material of the cylinder to form an electric field between impression roller and impression cylinder. If the impression roller has a stationary axis, the sliding ring is non-rotatably connected to the cylinder and electrically connected to the electrically conductive area. In this variant of the invention, the fixed axis can be connected to the electrical power supply. Via the axis, the electrical voltage passes through the sliding ring rotating with the cylinder to the electrically conductive area on the circumference of the cylinder, so that the electric field is formed between impression roller and impression cylinder. This voltage supply is particularly inexpensive and works very reliable. In particular, the wear of the seal ring can be kept low because it can have a line contact or surface contact with the shaft or axis. If the sliding ring also serves as a seal for a fluid, its wear is also reduced by the lubricating effect of the fluid. In addition, the sliding ring can be realized by means of inexpensive standard components. Furthermore, the sliding ring can have self-adjusting properties, in particular if it consists of an elastic material. As a result, the sliding ring can compensate for wear. The means for rotatably supporting the cylinder are preferably insulated from the cylinder or from a frame or frame made of metal, so that the charge does not flow from the cylinder to the mass.

According to one embodiment, the sliding ring sits on the periphery and / or the end face of the shaft or axis. In particular, it can press in the radial direction against the circumference of the shaft or axis or press in the axial direction against the end face of the shaft or axis. The chosen construction can be made dependent on the structural conditions of the impression roller to be equipped with the device for supplying an electrical voltage.

The slip ring may be a complete circumferential ring or consist of one or more ring segments. When executed from one or more segments, it may also be referred to as a "segment ring".

The shaft or axle according to one embodiment is made of steel or another metal.

According to a further embodiment, the shaft or axle is polished at least in the region on which the sliding ring rests. As a result, the wear of the seal ring is reduced and improves the contact between the seal ring and shaft or axis.

The device for supplying an electrical voltage can be designed such that it contacts the shaft or axis solely via at least one sliding ring. According to a preferred embodiment, the means for supplying an electrical voltage comprises a stator or rotor arranged concentrically with the cylinder axis at a distance from the shaft or axis, a cavity between the shaft and the stator or the axis and the rotor, an electrically conductive fluid into the cavity and the at least one sliding ring seals the cavity on at least one side. This embodiment comprises a device for supplying an electrical voltage to a fluid transmission system, as for example in the DE 20 2005 016 974 U1 or the EP 1 780 011 A1 is described. The electrically conductive fluid is z. As an oil or fat. A suitable electrically conductive roller bearing grease is z. B. from the company Klüber Lubrication Munich KG, Geisenhauerstrasse 7, 8379 Munich, Germany under the trade name Klüberlektrik B42-72 offered. The slip ring ensures the supply of electrical voltage, if the transmission by means of the electrically conductive fluid is ineffective, for example, because the fluid has leaked out of the cavity.

The stator is preferably circular-cylindrical, if the voltage is transmitted via the electrically conductive fluid to the circumference of the shaft. Accordingly, the rotor is preferably circular cylindrical when the voltage is transmitted to the circumference of the axis. In these cases, the cavity between the stator and the rotor is preferably sealed by sliding rings at both ends of the cavity. If the voltage is transmitted to a circular disk-shaped end face of the shaft, the stator is preferably likewise circular disk-shaped. If the voltage is transmitted to a circular disk-shaped end face of the axle, so also the rotor is preferably designed circular disk-shaped. In these cases, the cavity between shaft or axle and stator or rotor may be sealed externally by a single slip ring. In all the cases mentioned, a plurality of sliding rings can also be arranged directly next to one another in order to seal the cavity on one side several times, to ensure the supply of the electrical voltage in order to reduce the contact resistance.

According to a preferred embodiment, the sliding ring is a Simmerring of electrically conductive and flexible material. Simmerrings with the aforementioned properties are available. They are formed for example of Teflon or other plastic with graphite, carbon fiber or soot deposits. Suitable Simmerringe are for example offered by the company ... under the trade name ....

According to another embodiment, the sliding ring is a stuffing box ring made of an electrically conductive and flexible material. Stuffing box rings with the mentioned properties are available. These are, for example, stuffing box rings of Teflon or another plastic with deposits of graphite, carbon fibers or carbon black.

According to a preferred embodiment, the sliding ring consists of an elastic material, so that it has self-adjusting properties.

In a stuffing box ring readjustment can also be effected by a spring element which permanently presses the stuffing box ring against the shaft or axle. Accordingly, an adjustment by a spring element can be effected even with a Simmerring.

According to one embodiment, the shaft, on which the sliding ring is seated, supports the impression roller in a stationary pivot bearing. The shaft to the bearing of the impression roller is then also used as a contact element for the slide ring. In this The pivot bearing is arranged according to an embodiment in a frame or frame electrically isolated.

According to another embodiment, the shaft on which the sliding ring is seated, a rotatably connected to the end face of the cylinder shaft which is arranged concentrically to a shaft or axis to the bearing of the cylinder. This arrangement can be selected for a bearing with a shaft to the bearing of the impression roller, if for structural reasons, the slide ring can not be placed on the shaft to the bearing of the impression. Furthermore, the shaft rotatably connected to the end face of the cylinder can be provided when the impression roller is mounted on an axle. For this purpose, pivot bearings are arranged between cylinder and axle. Preferably, the pivot bearing relative to the axis or the axis with respect to a frame or frame to the bearing of the impression are isolated so that the charge does not flow from the cylinder to ground.

According to a further embodiment, the sliding ring is embedded on the circumference in a retaining ring or clamped between a stop on one side and a mounting ring on the other side or between the mounting ring on both sides. As a result, the sliding ring can be fixed with a defined preload.

According to one embodiment, a plurality of juxtaposed seal rings sitting on the shaft or axis. As a result, the risk of failure of the voltage supply can be avoided, since a multiple security for the voltage transmission is achieved. In addition, this can reduce the contact resistance and improve the charge supply.

According to a further embodiment, the shaft, on which the sliding ring is seated, is hollow cylindrical. This configuration can be selected, for example, when a shaft rotatably connected to the end face of the cylinder is arranged concentrically to a shaft or axis to the bearing of the cylinder. Furthermore, according to a further embodiment, a rotary feedthrough for compressed air can be extended through the hollow cylindrical shaft. Here, the hollow cylindrical shaft may be arranged on the end face of a shaft to the bearing of the cylinder. The rotary feedthrough in a sleeve system is used to inflate the sheath of the impression roller by means of compressed air in order to exchange it for another sheath.

The invention will be explained in more detail with reference to the accompanying drawings of exemplary embodiments. In the drawings show:

1 a Pressur with a shaft, a pivot bearing and means for supplying an electrical voltage with a stator surrounding the shaft and on the circumference of the shaft seated Simmeringen a fluid transmission system in partial longitudinal section;

2 a impression roller with a shaft and a device for supplying an electrical voltage with a stator surrounding the shaft and a Simmerring seated on the circumference of the shaft in partial longitudinal section;

3 a Pressur with a shaft and means for supplying an electrical voltage with a stator surrounding the shaft and a group on the circumference of the shaft seated Simmerringen in partial longitudinal section;

4 a Pressur with a shaft and means for supplying an electrical voltage with a rotor attached to the end of the shaft, a stator surrounding the rotor and a seated on the periphery of the rotor Simmerring and a rotary feedthrough for compressed air in the partial longitudinal section;

5 a impression roller with a shaft and means for supplying an electrical voltage with a rotor attached to the end face of the shaft, a stator surrounding it and Simmerringen seated on the rotor and an electrically conductive fluid in the partial longitudinal section.

In the following explanation of various exemplary embodiments, matching or essentially matching components are designated by the same reference numerals, differences being characterized by a following point and different numbers behind the point.

According to 1 has a press release 1.1 a cylinder 2 holding a metallic cylinder core 3 and a rubber elastic, electrically semiconducting layer 4 on the outer circumference. The layer 4 consists for example of rubber with embedded carbon black, carbon fiber or graphite particles. Furthermore, the pressur 1 one stuck to the cylinder core 3 connected wave 5 Made of steel, the two sides in pivot bearings in the form of radial ball bearings 6 is stored. The ball bearings 6 are on the one hand at a radial shoulder of the shaft 5 supported and on the other hand secured to an inserted into a groove of the shaft snap ring against axial displacement. The ball bearings 6 are outside in cups 7 made of electrically insulating material and the bearing shells 7 in a bearing cup carrier 8th stored, which is connected to a machine frame, not shown. The bearing shells 7 have a flange 7.1 at one end of a cylindrical section 7.2 ,

The size of the shaft 5 is a device for supplying an electrical voltage 9.1 assigned. This has an inside circular cylindrical stator 10 on that on the side of the cylinder core 3 by means not shown screws on the bearing shell carrier 8th is attached. Inside has the stator 10 two circular cylindrical sections 10.1 . 10.2 between which a diameter jump 10.3 is available. The section 10.2 has a larger diameter than the section 10.1 and in between is a diameter jump 10.3 available.

In the circular cylindrical section 10.1 with the large diameter sits another insulating bearing shell 11 that partially fit into the adjacent bearing shell 7 extends into it. The further bearing shell 11 lies with another flange 11.1 at the diameter jump 10.3 at. The flange 11.1 is at the end of a cylindrical section 11.2 arranged.

On the inner circumference of the cylindrical section 11.2 are a simmerring 12 made of electrically conductive material, the inside of the circumference of the shaft 5 seated, an electrically conductive ring 13 , z. B. metal, which has a small distance from the shaft, and another Simmerring 14 made of electrically conductive material, the inside of the circumference of the shaft 5 seated, arranged. This arrangement is on the other side at one to the shaft 5 coaxial, circular cylindrical support section 15.1 on the side of a support disk 15.2 supported, located on the other side on the pivot bearing 6 supported. By screwing the stator with the bearing cup carrier, the shaft bearing and the Simmerringe and the metal ring are secured in the positions shown.

Between the electrically conductive ring 13 , the Simmerrings 12 . 14 and the circumference of the shaft 5 is a cavity 16 present, which is filled with an electrically conductive grease.

The stator 10 has a radial insertion hole 17 for an electrical connector 18 an electrical power supply. The further bearing shell 11 and the ring 13 have aligned insertion holes 19 . 20 on. The insertion holes 19 . 20 the further bearing shell 11 and the ring 13 are sized so that an end-side pin 21 of the connector 18 is clamped plugged. The pin 21 can be equipped for a good contact with resilient segments.

From the electrical power supply is via the connector 18 an electrical voltage to the ring 13 made of electrically conductive material. From the ring 13 From the voltage comes over the Simmerringe 12 . 14 and the electrically conductive grease to the periphery of the shaft 5 , By the wave 5 will the voltage over the cylinder core 3 to the layer 4 of the impressionist 1.1 forwarded.

The execution of 2 differs from the above-described in that the means for supplying an electric voltage 9.2 only one Simmerring 14 having. Thus, the means of the connector 18 to the ring 13 applied voltage of a power supply through the electrically conductive Simmerring 14 on the circumference of the shaft 5 and from there over the cylinder core 3 on the outer layer 4 of the impressionist 1.2 transfer. This embodiment has no cavity with an electrically conductive fluid.

The impressionist 1.3 from 3 differs from the above-described in that the means for supplying an electric voltage 9.3 three side-by-side Simmerrings 14.1 . 14.2 . 14.3 made of electrically conductive material. Between adjacent Simmerrings 14.1 . 14.2 . 14.3 are spacers 22.1 . 22.2 arranged. The spacer rings 22.1 . 22.2 are also made of metal or another electrically conductive material.

One by means of the connector 18 a high voltage supply and the ring 13 introduced voltage is via the spacer rings 22.1 . 22.2 and Simmerrings 14.1 . 14.2 . 14.3 to the circumference of the shaft 5 transferred and passes from there over the cylinder core 3 to the coat 4 of the impressionist 1.3 , Optionally, the cavities 16.1 . 16.2 be filled between the Simmerringen with an electrically conductive fluid. As a result, where appropriate, the life of the Simmerringe 14.1 . 14.2 . 14.3 can be increased because the fluid causes lubrication, which can reduce the wear of the Simmerringe.

In the execution of 4 is the wave 5 a press course 1.4 in radial ball bearings 6 stored, which has an insulating bearing shell 7 are supported in a machine frame, not shown. The wave 5 has a central threaded hole 24 for supplying compressed air for the purpose of exchanging a sleeve sleeve on the jacket of the impression roller 1.4 ,

A rotary union 25 for feeding compressed air is in the threaded hole 24 in the front of the shaft 5 screwed.

Further, a rotor 26 with a hollow cylindrical section 26.1 and a flange 26.2 at one end by means of screws 27 to the front of the shaft 5 screwed. The rotor 26 is made of an electrically conductive material, in particular steel.

The hollow cylindrical section 26.1 of the rotor 26 is of a substantially circular cylindrical stator 10 surround. The stator 10 consists of an electrically insulating material. He is about screws 27 fixed to a machine frame fixed mounting plate.

In the stator 10 is a metallic ring 13 used on the inner circumference of the stator 10 is fixed by means not shown. The stator 10 and the ring 13 have aligned insertion holes 17 . 20 on, in which a connector 18 with a contact pin 21 is used.

Between the ring 13 and the mounting plate 28 is a simmerring 14 made of electrically conductive material. The simmerring 14 has a rigid, L-shaped base 29.1 , Wherein on the leg perpendicular to the shaft of the base an elastically deformable portion 29.2 of the simmerring 14 is fixed in acute-angled alignment with this leg. The cavity 16 between the ring 13 and the simmerring 14 can also be filled with an electrically conductive fluid.

One by means of the connector 18 Voltage supplied by a high voltage power supply enters the metallic ring 13 initiated and passes over the Simmerring 14 and optionally the electrically conductive fluid on the jacket of the cylindrical portion 26.1 of the rotor 26 ,

From the rotor 26 the voltage passes over the shaft 5 and the cylinder core to the jacket of the impression roller 1.4 ,

The impressionist 1.5 from 5 differs from the above-described in that on the inner circumference of the stator 10 on the two sides of the ring 13 one simmerring each 29 is arranged made of electrically conductive material. The additional Simmerring 29 supported on the one hand on the flange of the stator 10 and on the other hand on the ring 13 from.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0556463 B1 [0004]
• EP 1780011 A1 [0006, 0016]
• DE 202007002726 U1 [0007]
• DE 202005016974 U1 [0016]

Claims (14)

Impression roller of a rotary printing press with - a cylinder ( 2 ), at least in one area ( 4 ) is more or less electrically conductive, - means for rotatable bearing ( 6 ) of the cylinder about its cylinder axis and - at least one device for supplying an electrical voltage ( 9 ) to the electrically conductive area ( 4 ), - one electrically conductive, to the cylinder ( 2 ) coaxial wave ( 5 ) or axis and - at least one to the cylinder ( 2 ) coaxial sliding ring ( 12 . 14 . 29 ) made of electrically conductive and flexible material, which on the shaft ( 5 ) or axle slidably seated, - whereby either the electrically conductive shaft ( 5 ) rotatably with the cylinder ( 2 ) and electrically connected to the electrically conductive region of the cylinder ( 2 ), the sliding ring ( 12 . 14 . 29 ) is stationary and can be connected to an electrical power supply, - or the sliding ring ( 12 . 14 . 29 ) rotatably with the cylinder ( 2 ) and electrically connected to the electrically conductive area ( 4 ) Is connected and the axis is arranged stationary and can be connected to an electrical power supply. A blank according to claim 1, wherein the sliding ring ( 12 . 14 . 29 ) on the circumference and / or the front side of the shaft ( 5 ) or axle is seated. A blank according to claim 1 or 2, wherein the shaft ( 5 ) or axle made of steel. Compression blank according to one of Claims 1 to 3, in which the shaft ( 5 ) or axis at least in the region at which the sliding ring ( 12 . 14 . 29 ), is polished. A blank according to any one of claims 1 to 4, wherein the means for supplying an electrical voltage ( 9 ) a distance from the shaft ( 5 ) or axis concentric with the cylinder axis arranged stator ( 10 ) or rotor ( 26 ) and a cavity ( 16 ) between the shaft ( 5 ) and the stator ( 10 ) or the axis and the rotor ( 26 ), an electrically conductive fluid in the cavity ( 16 ) and the at least one sliding ring ( 12 . 24 . 29 ) the cavity ( 26 ) seals on at least one side. Pressurizer according to one of Claims 1 to 5, in which the sliding ring ( 12 . 14 . 29 ) is a Simmerring of electrically conductive and flexible material. A blank according to any one of claims 1 to 5, wherein the sliding ring is a stuffing box ring made of an electrically conductive and flexible material. Pressurizer according to one of Claims 1 to 7, in which the sliding ring ( 12 . 14 . 29 ) consists of an elastic material. Pressurizer according to one of Claims 1 to 8, in which the shaft ( 5 ) on which the sliding ring ( 12 . 14 . 29 ), the impression roller in a stationary pivot bearing ( 6 ) stores. A blank according to any one of claims 1 to 8, wherein the shaft on which the sliding ring ( 12 . 14 . 29 ), one with the front side of the cylinder ( 2 ) rotatably connected shaft which is concentric with a shaft ( 5 ) or axis to the bearing of the cylinder is arranged. Pressurizer according to one of Claims 1 to 10, in which the sliding ring ( 12 . 14 . 29 ) embedded in a retaining ring on the circumference or between a stop on one side and a mounting ring on the other side or between mounting rings ( 22 ) is clamped on both sides. A blank according to any one of claims 1 to 11, wherein a plurality of juxtaposed sliding rings ( 12 . 14 . 29 ) on the shaft ( 5 ) or axle. A blank according to any one of claims 1 to 12, in which the shaft on which the sliding ring ( 12 . 14 . 29 ) is seated, is hollow cylindrical. A blank according to claim 14, wherein a rotary feedthrough ( 25 ) for compressed air through the hollow cylindrical shaft ( 5 ) is extended therethrough.

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