ES2650315T3 - Refrigerated bar guide roller - Google Patents

Abstract

Bar guide roller (30) for guiding a steel bar in a continuous casting machine, featuring - a left bearing support (10a) and a right bearing support (10b); - a fixed axis (11), where the fixed axis (11) is joined with the left bearing support (10a) and with the right bearing support (10b) rigidly with respect to torsion; - a cylindrical roller cover (12), as well as a left bearing (13a) and a right bearing (13b), where the roller cover (12), through the left bearing and the right bearing (13a, 13b), it is mounted rotatably with respect to the fixed axis (11); and - a water pipe cover (1), where the water pipe cover (1) can conduct cooling water from a left cavity (14a) between the shaft (11) and the water pipe cover (1) , in the area of the left bearing (13a), towards a longitudinal space (16) between the water conduction cover (1) and the roller cover (12), along the longitudinal space (16) in the axial direction ( x) and in tangential direction (t), and from the longitudinal space (16) towards a right cavity (14b) between the water conduction cover (1) and the fixed axis (11), in the area of the right bearing ( 13b).

Description

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DESCRIPTION

Refrigerated bar guide roller Technical field

The present invention refers to a bar guide roller for guiding a steel bar in a continuous casting machine and to a method for cooling the bar guide roller in the continuous casting machine through a refrigerant.

State of the art

From WO 2004/065040 A1 a bar guide roller is known, in which a coolant first cools a bearing in a left bearing support, the coolant, from the left bearing support, circulates through the roller towards the support of right bearing, cooling a bearing there. In the known bar guide roller, the fact that the refrigerant, from a bearing support, must be introduced into the roller by means of a rigid or flexible connecting piece and by means of a rotation passage, as well as to be moved again on the opposite side. Due to this, the robustness of the roller is limited.

This document does not indicate how construction can be simplified, so that in particular sensitive rotation steps can be dispensed with.

Summary of the Invention

The object of the present invention is to indicate a chilled bar guide roller for guiding a steel bar in a continuous casting machine, which is characterized by a particularly simple construction and is particularly robust and not prone to failure. Due to this, the transit time of the bar guide roller must also be prolonged in the case of unfavorable conditions in the continuous casting machine.

Another object of the invention is to indicate a method for cooling a rod guide roller in a continuous casting machine, where the refrigerant cools the two bearing supports, and where the refrigerant, in the path between the two bearing supports, cools the bearings and the cylindrical roller cover. Thanks to this, a so-called "cooled on the periphery" bar guide roller is created, which, due to compactness and reliability, is also suitable for continuous billet, billet and profile casting machine. Because of this, cracking-sensitive steel classes can also be molded into a continuous casting machine to obtain elongated products.

The first object will be reached through a guide bar roller to guide a steel bar in a continuous casting machine, presenting:

- a left bearing support and a right bearing support;

- a fixed axis, where the fixed axis is connected with the left bearing support and with the right bearing support rigidly with respect to the torsion;

- a cylindrical roller cover and a left bearing and a right bearing, where the rotating roller cover, through the left bearing and the right bearing, is rotatably mounted with respect to the fixed axis; Y

- a water conduction cover, where the water conduction cover can conduct cooling water from a left cavity between the shaft and the water conduction cover, in the area of the left bearing, towards a longitudinal space between the cover of water conduit and the roller cover, along the longitudinal space in axial direction and radial direction, and from the longitudinal space towards a right cavity between the water conduction cover and the fixed axis, in the right bearing area .

Through the realization of the bar guide roller with a fixed axis, which, both with the left bearing support and with the right bearing support, is rigidly connected with respect to the torsion, a roller is created which it travels particularly smoothly, with a reduced mass inertia torque. In this way, the contact between the roller cover surface and the casting bar can be reliably maintained, also in the case of temporary casting conditions. The rigid connection with respect to the torsion can take place, for example, in a positive way (for example through a key) or in a non-positive way (for example through a joint by contraction or by a forced adjustment, as well as through of friction). The left bearing is cooled through the refrigerant in the left cavity. The surface of the cylindrical roller cover is cooled by the

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refrigerant in the longitudinal space, where an especially uniform temperature distribution is achieved through the refrigerant guidance in axial direction and tangential direction. Finally, the right bearing is cooled by the refrigerant in the right cavity.

The water conduction cover, from sheet metal parts, can be produced especially easily and economically when it presents:

- a cylindrical tube whose wall thickness is less than the longitudinal extension of the cylindrical tube;

- several external tangential segments that extend over the cover surface in axial direction over the longitudinal extension of the tube, where two consecutive external segments have a distance in axial direction with respect to each other; Y

- an axial external segment that extends over the outer cover surface of the tube in the axial direction over the longitudinal extension of the tube, where respectively two consecutive tangential external segments, alternately, have a passage opening for the cooling water in the right or left side of the axial outer segment, observed in the axial direction.

Through the water conduction cover a refrigerant is introduced from a cavity between the water conduction cover and a fixed axis, in a longitudinal space between the roller cover and the water conduction cover, it is guided in the space longitudinal, both in the axial direction and also in the tangential direction, and is guided from the longitudinal space into a closed cavity between the water conduction cover and the fixed axis. In this way, not only a particularly uniform distribution of the surface temperature of the roller cover is achieved, but also the left and right bearings are cooled.

The cylindrical tube, the tangential external segments and the axial external segment are preferably curved pieces of sheet metal, where the external segments are connected to the tube through coupling (for example welding, soft welding or adhesion).

An alternative water conduction cover features:

- a cylindrical tube whose wall thickness is less than the longitudinal extension of the cylindrical tube;

- at least one spiral-shaped outer segment, which extends over the outer cover surface of the tube, at least once in a spiral shape around the longitudinal extension of the tube.

In this variant of the water conduction cover, the refrigerant is guided through at least one, possibly several, spiral external segments, in a tangential and axial direction along the roller cover, due to the which on the roller cover also regulates a uniform distribution of surface temperature. The spiral-shaped outer segment can be attached to the tube by coupling, or it can be roughed out from the tube through milling or turning.

It is especially considered convenient that the internal segment has at least one, preferably two or several internal segments extending from the inner cover surface of the tube in the radial direction to the fixed axis. This avoids a so-called "hydraulic short circuit" between two cavities that are respectively between the left area of the shaft end and the roller cover and the right area of the shaft end and the roller cover. In this way, the refrigerant is forced to circulate from the left cavity along the longitudinal space, towards the right cavity, due to which a great heat dissipation of the casting product is guaranteed.

It is considered advantageous that the left bearing support and the right bearing support respectively have a bore to accommodate the fixed shaft, where the bearing support has at least one cavity, preferably closed, in a tangential direction, around the bore. Through the cavity in the bearing support around which refrigerant circulates, both the bearing support itself and also a sealing element for sealing are cooled from the outside.

In order to introduce the refrigerant from the bearing support into the shaft, it is considered convenient that the cavity in the bearing support has an essentially radial bypass line to guide the cooling water from the bearing support towards the shaft. Although a radial branch line has the shortest length, it is not necessary that the branch line be arranged exactly radially.

It is considered advantageous that each half of the fixed axis has a separate axial line in the longitudinal direction to conduct refrigerant and a bypass line connected thereto, in a cavity.

To seal the left bearing with respect to the left cavity in a sealed manner with respect to the fluids, as well as the right bearing with respect to the right cavity, at least one joint element is provided respectively.

Simple sealing, fluid-tight, can take place, for example, through a so-called 5 ring of the Prelon type (see, for example, application WO 2011/117383 A1 for the realization of joints in guide rollers of bars with rings Prelon type), through an O-ring or rotating joints as sliding rings.

The protection of the bearing with respect to the environment can take place, for example, through seals for radial or labyrinth shafts. However, of course, other variants for the sealing of bearings are also known to the expert.

The second mentioned object will be achieved through a method for cooling a bar guide roller in a continuous casting machine through a coolant, where the bar guide roller comprises

- a left bearing support and a right bearing support with a left bearing and a right bearing;

- a fixed axis;

15 - a cylindrical roller cover, where the rotating roller cover, by means of the left bearing and the bearing

right, it is rotatably mounted with respect to the fixed axis;

which presents the following steps of the method:

- coolant circulation around the fixed axis inside the left bearing support; then

- coolant inlet from the left bearing support towards the fixed shaft;

20 - circulation through a first axial line of the fixed axis;

- entry into a cavity of the bar guide roller;

- circulation around the cavity, where the left bearing and the right bearing are cooled;

- circulation through a second axial line of the fixed axis;

- coolant inlet from the fixed shaft to the right bearing support;

25 - Coolant circulation around the fixed axis inside the right bearing support.

Through the complete circulation around the fixed axis, preferably in the circumferential direction, inside the left bearing support, as well as the right bearing, the respective bearing support is cooled. The two bearings on the shaft and the roller cover are also cooled through the circulation around the cavity.

30 To avoid the above-mentioned hydraulic short circuit, it is considered advantageous that the cavity has a left cavity, a longitudinal space and a right cavity, where the refrigerant circulates from the left cavity to a longitudinal space between a water conduction cover and the cover of the roller; the refrigerant circulates in the axial direction through the longitudinal space; and then the refrigerant circulates from the longitudinal space towards the right cavity.

35 Thus, a so-called chilled bar guide roller in the periphery is performed.

In order to reach a particularly uniform temperature of the surface on the roller cover, it is considered advantageous that the refrigerant, when circulating through the longitudinal space, additionally performs a tangential movement around the fixed axis.

Brief description of the drawings

Other advantages and features of the present invention result from the following description of non-limiting examples of execution, where the figures show:

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Figure 1: a perspective view of a bar guide roller according to the invention;

Figure 2: a view from the right of the bar guide roller according to figure 1;

Figure 3: a view from the right of a variant of the bar guide roller according to figure 1;

Figure 4: a sectional representation along lines A-A of Figure 2;

Figure 5: a perspective view of a first variant of a water conduction cover;

Figure 6: a perspective view of a second variant of a water conduction cover;

Figure 7: A longitudinal section relative to Figure 6.

Description of the forms of execution

Figure 1 shows a perspective representation of a non-driven bar guide roller 30 according to the invention for supporting and driving a steel bar with billet or billet profile in a continuous casting machine. The steel bar not shown rests on the cylindrical surface of the rotating cover of the roller 12, where the roller cover 12, by means of bearings 13a, 13b not shown in figure 1 (see figure 4), is mounted so rotating on the fixed axis 11.

A side view of the bar guide roller 30 of Figure 1 is shown in Figure 2. Each bearing support 10a, 10b can be attached to the roller guide or to a section of the roller guide by means of eccentric perforations and fixing means not represented, like screws.

In figure 3 a right bearing support 10b and the circulation through the bearing support with a coolant (for example water) are schematically represented. In this way, the cooling water, as represented by the lower arrow, enters from below in the bearing support 10b, circulating upwards in a vertical direction. Then, the cooling water is diverted four times, each time at 90 °, so that the cooling water can circulate completely in a closed cavity 14, around the fixed axis 11. Due to this, a uniform cooling of the axis is ensured 11, as well as roller cover 12 attached to the shaft. The cooling water, from the cavity 14, by means of a radial bypass line 15, can enter an axial line 22 within the axis 11. In addition, grease or lubricating oil can be introduced by drilling for lubricant 21 ', to lubricate the bearing 13b. By means of the drain holes 24 that are arranged in the sealed area, respectively between the bearing space filled with grease or oil and the cavity 14, 14a, 14b filled with water, both water or grease / oil can be transported to the environment without pressure, by means of the fixed axis 11. In this way, an operator can immediately control the operating capacity of the bar guide roller 30 without having to act on the roller.

Figure 4 shows that cooling water, from the bypass line 15, through an axial line 22 and a radial perforation, can enter a cavity 14, 14a, which is limited by the fixed axis 11, the housing rotating support 23 and the water conduit cover 1. Through the cavity 14a which is connected to the longitudinal space 16 between the water conduit cover 1 and the inner cover surface of the roller cover 12, the gasket Prelon type 17 and bearing 13a are refrigerated. The Prelon type gasket, on its inner cover surface, has three dynamic gasket elements (specifically sliding rings), and on its outer cover surface it has two static gasket elements (in this case O-rings). During operation, the Prelon-type seal 17 which rotates at the same time (also called the Prelon-type ring) rests on the fixed shaft 11. To prevent the bearings 13a, 13b from getting dirty, the bearing 13a is sealed with respect to to the bearing support 10a, by means of a labyrinth seal 19 and a radial shaft retainer 18. The same is true of the right bearing 13b in the bearing support 10b. The water conduit cover 1 shown in detail in Figure 6 fulfills the following functions: On the one hand, a hydraulic short circuit between the left cavity 14a and the right cavity 14b is prevented. In this way, the cooling water is forced to circulate from the left cavity 14a, through the longitudinal space 16, to the right cavity 14b. Through the circulation through the longitudinal space 16, in axial and tangential direction, a uniform temperature of the surface of the cover of the roller 12 is achieved, as well as of the steel bar resting on it. The fixed shaft 11 is non-positively connected with a bearing support 10a, 10b. The support housing 23 is attached to the roller cover 12, in a sealed manner, by a weld joint.

A first variant of the water conduction cover 1 is shown in Fig. 1. The water conduction cover has a thin-walled cylindrical tube 2, an axial outer segment 6 extending in an axial direction x on the length of the tube 2, and several external segments 5 tangential, arranged separately, one behind the other in axial direction. To force the cooling water into the longitudinal space between the

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water conduit cover 1 and the roller cover, the conduit cover, on the inner cover surface of the tube 2, further comprises at least one internal segment 9, in this case two. In this way, the inner side of the roller cover 2 is cooled through the cooling water in the direction represented by the arrows.

Figure 6 shows a second variant of the water conduit cover 1. In this case, the cooling water circulates around the water conduit cover 1, as well as the internal surface of the roller cover 12, by way of of a spiral

Figure 7 shows a longitudinal section through the water conduit cover 1 of Figures 4 and 6. The spiral-shaped outer segment 8, as well as the internal segments 9, are welded with the tube 2.

While the invention was illustrated and described in detail through the preferred exemplary embodiments, the present invention is not limited to the described examples, so that the expert can deduce other variants based on it, without abandoning the scope of protection. of the invention.

Reference List

1 water conduction cover

2 tube

3 wall thickness

4 longitudinal extension

5 tangential external segment

6 axial external segment

7 passage opening

8 spiral-shaped outer segment

9 internal segment

10a, 10b bearing support

11 axis

12 roller cover 13a, 13b bearing

14, 14a, 14 cavity

15 branch line

16 longitudinal space

17 Prelon type ring

18 radial shaft seal

19 maze board

20 circumferential groove

21 drilling

21 'lubricant drilling

22 axial line

23 support housing

24 drain drilling

5 30 bar guide roller

r radial direction t tangential direction x axial direction

Claims (13)

5 10 fifteen twenty 25 30 35 40 Four. Five 1. Bar guide roller (30) to guide a steel bar in a continuous casting machine, presenting - a left bearing support (10a) and a right bearing support (10b); - a fixed shaft (11), where the fixed shaft (11) is connected with the left bearing support (10a) and with the right bearing support (10b) rigidly with respect to the torsion; - a cylindrical roller cover (12), as well as a left bearing (13a) and a right bearing (13b), where the roller cover (12), through the left bearing and the right bearing (13a, 13b), it is rotatably mounted with respect to the fixed axis (11); Y - a water conduction cover (1), where the water conduction cover (1) can conduct cooling water from a left cavity (14a) between the shaft (11) and the water conduction cover (1), in the area of the left bearing (13a), towards a longitudinal space (16) between the water conduction cover (1) and the roller cover (12), along the longitudinal space (16) in the axial direction (x) ) and in the tangential direction (t), and from the longitudinal space (16) to a right cavity (14b) between the water conduit cover (1) and the fixed axis (11), in the right bearing area (13b ). 2. Bar guide roller according to claim 1, characterized in that the water conduit cover (1) has: - a cylindrical tube (2), whose wall thickness (3) is smaller than the longitudinal extension (4) of the cylindrical tube (2); - several external tangential segments (5) extending over the cover surface (2) in axial direction (x) over the longitudinal extension (4) of the tube (2), where two consecutive external segments (5) have a distance in axial direction (x) with respect to each other; - an axial external segment (6) extending over the outer cover surface of the tube (2) in the axial direction (x) over the longitudinal extension (4) of the tube (2), where respectively two tangential external segments (5) consecutively, alternately, they have a passage opening (7) for the cooling water on the right or left side of the axial outer segment (6), observed in the axial direction (x). 3. Bar guide roller according to claim 1, characterized in that the water conduit cover (1) has: - a cylindrical tube (2), whose wall thickness (3) is smaller than the longitudinal extension (4) of the cylindrical tube (2); - at least one spiral-shaped outer segment (8), which extends over the outer cover surface of the tube (2), at least once in a spiral shape around the longitudinal extension (4) of the tube (2) ). 4. Guide bar roller with a water conduit cover (1) according to one of claims 2 or 3, with at least one, preferably with two, internal segments (9), extending from the inner cover surface of the tube (2) in radial direction (r) to the fixed axis (11). 5. Bar guide roller according to one of the preceding claims, wherein the left bearing support (10a) and / or the right bearing support (10b) respectively have a bore (21) to accommodate the fixed shaft (12), characterized because the bearing support (10a, 10b) has at least one cavity (14, 14a, 14b), preferably closed, in a tangential direction (t), around the bore (21). 6. Bar guide roller according to claim 5, characterized in that the cavity (14, 14a, 14b) in the bearing support (10a, 10b) has an essentially radial bypass line (15) for guiding the water of cooling from the bearing support (10a, 10b) to the shaft (12). 7. Guide bar roller according to one of the preceding claims, characterized in that each half of the fixed axis (11) has an axial line (22) for conducting refrigerant and a bypass line (15) connected thereto, which extends essentially radially, in a cavity. 8. Guide bar roller according to one of the preceding claims, characterized in that the left bearing and / or the right bearing (13a, 13b), with respect to the cavity (14, 14a, 14b), are sealed tightly in as for the fluids, respectively by means of a joint element. 5 10 fifteen twenty 25 9. Guide bar roller according to claim 8, characterized in that the seal element is a Prelon type ring (17). 10. Bar guide roller according to one of the preceding claims, characterized in that the fixed shaft (11) has a drain hole (24), where it connects the external environment with a sealed area. 11. Method for cooling a bar guide roller (30) in a continuous casting machine through a coolant, where the bar guide roller (30) comprises - a left bearing support (10a) and a right bearing support (10b) with a left bearing (13a) and a right bearing (13b); - a fixed axis (11); - a cylindrical roller cover (12), where the rotating roller cover (12), by means of the left bearing and the right bearing (13a, 13b), is rotatably mounted with respect to the fixed axis (11); which presents the following steps of the method: - coolant circulation around the fixed shaft (11) inside the left bearing support (10a); then - coolant inlet from the left bearing support (10a) towards the fixed shaft (11); - circulation through a first axial line (22) of the fixed axis (11); - entry into a cavity (14) inside the bar guide roller (30); - circulation around the cavity (14), where the left bearing and the right bearing (13a, 13b) are cooled; - circulation through a second axial line (22) of the fixed axis (11); - coolant inlet from the fixed shaft (11) to the right bearing support (10b); - refrigerant circulation around the fixed shaft (11) inside the right bearing support (10b). Method according to claim 11, characterized in that the cavity (14) has a left cavity (14a), a longitudinal space (16) and a right cavity (14b), where the refrigerant, from the left cavity (14a), circulates towards a longitudinal space (16) between the water conduction cover (1) and the roller cover (12); the refrigerant circulates through the longitudinal space (16) in the axial direction (x); and then the refrigerant circulates from the longitudinal space (16) to the right cavity (14b). 13. Method according to claim 12, characterized in that the refrigerant, when circulating through the longitudinal space (16), additionally performs a tangential movement (r) around the fixed axis (11).