JP2000024760A - Twin roll type casting apparatus and bearing device used for this apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To minimize the permanent deformation of a shaft owing to a thermal expansion effect. SOLUTION: A casting roll 1 in a twin roll type casting apparatus has end shaft forming parts fitted in bearings 41, 42. The bearing 41 is a self-matching bearing, with which the center zone 47 of the shaft forming part 21 is positively positioned, but the angled shaking of the shaft forming part 21 centered on the center zone 47 is allowed. The bearing 42 is a flat cylindrical roller bearing permissible of movement in the longitudinal direction of the bearing forming part 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a twin-roll casting device and a bearing device used for the device.

[0002]

2. Description of the Related Art In a twin-roll casting apparatus, molten metal is introduced between a pair of horizontal casting rolls that are cooled and rotate in mutually opposite directions, a metal shell is solidified on a moving roll surface, and the molten metal is introduced into a roll gap. The metal shells are coalesced and fed downward from the nip between the rolls as a solidified strip. As used herein, the term "roll gap" is intended to refer to the entire area where the rolls are closest. The molten metal is poured from the ladle into one or a series of small containers, from which it flows to a metal feed nozzle located above the roll gap and into the roll gap, and consequently roll casting just above the roll gap A casting pool of molten metal supported on the surface can be formed. The end of the casting pool may be a side dam or side plate held in sliding engagement with the roll end surface.

[0003]

The casting surface of the casting roll is generally provided by an outer peripheral wall with a longitudinal cooling water passage through which water is supplied and drained via a substantially radial passage in the roll end wall. . When casting ferrous metal, roll temperature is 1640 ℃
In order to achieve uniform solidification of the metal and to avoid local overheating of the roll surface, the circumference of the roll must be maintained at a very uniform temperature. No.

[0004] Even with effective water cooling, it is inevitable that the roll will be greatly distorted due to the thermal expansion effect during casting.
The roll support shaft tends to move in the support bearing due to such roll distortion. For example, a typical roll may have a longitudinal expansion of the order of a few millimeters due to roll heating during casting. We determine that these movements cause significant control problems in the operation of twin roll casting equipment, especially during high temperature operations in solidified strip casting of steel. Since conventional roll-supported bearings do not allow the supporting shaft to move, the shaft must be deformed to accommodate the thermal expansion effects of the roll, thereby creating a large lateral force on the shaft at the bearing support. The thickness of the solidified strip is generally controlled by mounting a bearing on at least one of the rolls to a movable chock that allows lateral movement of the rolls. Usually, the bearing support of one roll is fixed and the bearing support of the other roll is movable under spring bias or hydraulic bias. If the shaft skews and creates lateral forces on the bearing, these forces can cause lateral swinging of the floating roll in an uncontrollable manner, causing severe dimensional variations in the solidified strip. Furthermore, since the axial deformation due to the thermal expansion effect can be a permanent deformation, accurate mechanical finishing is not possible when re-polishing for later use. This is because the roll must be supported on its shaft during such finishing. The present invention provides a novel support for the rolls of a twin roll casting machine that can essentially overcome the above problems due to the thermal expansion effects during casting.

[0005]

According to the present invention, a pair of casting rolls forming a roll gap between them, and molten metal is supplied to the roll gap between the casting rolls to form a roll on a roll casting surface above the roll gap. A metal supply nozzle for forming a supported molten metal casting pool, a pair of pool defining walls engaging the ends of the casting roll to define a casting pool at the end of the roll gap, In a twin-roll casting apparatus composed of a combination with a roll driving means for producing a solidified strip of metal fed downward from a roll gap by being driven to rotate, each casting roll can be rotated within a pair of rotating bearings A pair of end shaft forming portions attached to the roll assembly, and the bearing at one end of the roll assembly positively positions the center region of the shaft forming portion at one end of the roll, but the shaft shapes centered on the center region. Allowing angular oscillation of the parts, the bearing of the roll assembly and the other end is allowed longitudinal movement of the shaft forming part of the other end of the roll assembly, twin roll casting apparatus is provided.

[0006] Preferably, the bearing at the other end of the roll assembly includes an inner race member fixed to a corresponding shaft forming portion, an outer race member fixed to a bearing support, and an inner race member rotating inside the outer race member. It can be a flat cylindrical roller bearing, each consisting of a set of cylindrical rollers that allow the inner race member to move in the longitudinal direction of the axis of rotation.

In addition, each of the bearings at one end of the roll assembly
A roller bearing comprising an inner sleeve fixed to a corresponding shaft forming portion, an outer housing member fixed to a bearing support, and a plurality of rollers disposed between and engaged with the inner sleeve and the outer housing member. A bearing device is provided.

[0008] Preferably, the inner sleeve and the outer housing member define a plurality of individual roller races spaced longitudinally of the corresponding shaft formation, each centered in a central region of the shaft formation. By having a curved outer roller track, rotation of the outer housing member about the central region of the shaft forming portion is allowed. For example, a central roller race surrounding the central region of the shaft forming portion can be provided, juxtaposed to a pair of outer roller races spaced on each side of the central region of the shaft forming portion.

[0009] More preferably, at least one of the bearings at one end of the roll assembly is provided with adjustment means operable to adjust the longitudinal positioning of the supporting shaft formation. This allows the roll ends to be precisely aligned with each other in the initial assembly.

[0010] The adjusting means may comprise an adjusting mechanism operable to move the one bearing in the corresponding bearing support, and a locking means for locking the bearing to the bearing support.

Therefore, the bearing at one end fixes the shaft forming portion of the casting roll against the movement in the longitudinal direction and allows angular rotation of the shaft about the central region, and the bearing at the other end is In the radial direction and allow movement in the longitudinal direction.

For this reason, the bending force acting on the casting roll due to the thermal expansion effect is accepted by the self-alignment characteristic of the bearing that allows the shaft to swing angularly, so that the permanent deformation of the shaft due to the bending force can be minimized. .

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to more fully explain the present invention, embodiments will be described in detail with reference to the accompanying drawings.

FIGS. 1 to 4 show an embodiment of the present invention. The illustrated strip casting apparatus comprises a pair of casting rolls 1 forming a roll gap 2 between them. In the casting operation, molten metal is supplied from a ladle (not shown) to a roll gap 2 between casting rolls 1 via a tundish 3, a distributor 4 and a metal supply nozzle 5, and melts above the roll gap 2. Creates a metal pool 6. The ends of the casting pool 6 are defined by a pair of refractory walls 10.
It engages the notched end of the casting roll 1 as shown below. By moving the stopper rod 7 provided on the tundish 3, the molten metal can flow down from the tundish 3 to the distributor 4 via the outlet nozzle 8 and the refractory shroud 9.

The casting roll 1 is provided with an inner water cooling passage, in a manner described in detail below, and the continuous metal solidified strip 11 is rotated by rotating the casting roll 1 in mutually opposite directions by means of a drive (not shown). Is produced and fed downward from the roll gap 2 between the casting rolls 1.

As far as has been described, the illustrated apparatus is described in more detail in US Pat. No. 5,488,988 and Australian Patent 664670. Reference can be made to these patents for details of the construction and operation of the device.

The two casting rolls 1 have the same construction, and are made of a tube or tubular roll body 20 made of copper or copper alloy, respectively.
And a pair of end shaft forming portions that are stub shafts 21 and 22 made of stainless steel fixed to the end of the tubular roll body 20. The tubular roll body 20 is provided with an end notch 23, between the pair of shoulders 24 which engage the refractory defining wall 10, the main part of the relatively thick wall forms the casting surface 25 of the roll. The stub shaft 22 is much longer than the stub shaft 21 and has a two-way connection for connection with a rotary water flow joint (not shown).
A pair of water outlets 33 and 34 are provided. The water flow through the passages in the roll does not form part of the present invention and will not be described further.

A stub shaft 21 at one end of the roll assembly is mounted on a roller bearing 41 of a pair of self-aligning bearing devices.
The stub shaft 22 at the other end of the roll assembly is simply attached to a cylindrical roller bearing 42. The roller bearing 41 of the self-aligning bearing device has a lateral positioning track of the roll (not shown).
Each bearing 42 is also mounted on a chock 43, which is a bearing support that can move above, and also rolls a track (not shown).
Is mounted on a chock 45, which is a bearing support that can be positioned laterally along.

Each roller bearing 41 of the bearing device fixes an alignment point 47 in the central region of the stub shaft 21 against movement in the longitudinal direction, and angularly swings the axis about the fixed alignment point 47. Is configured to support the stub shaft 21 so as to be possible. On the other hand, a roller bearing 42 supporting the stub shaft 22 at the other end of the roll assembly provides radial support for the stub shaft 22, but allows for longitudinal movement of the stub shaft 22 by allowing relative movement between the inner and outer races of the bearing. ing.

The configuration of the roller bearing 41 of the self-aligning bearing device is best shown in FIG. As shown in this figure, the roller bearing 41 includes an inner sleeve 51 fixed to the stub shaft 21 by a fastener 52 and a bearing housing 5 fastened to a chock 43 serving as a bearing support.
4 and an outer housing member 53 held by the outer housing member 53.
A series of three roller races 55, 56, 56 are positioned between the inner sleeve 51 and the outer housing member 53. More specifically, a central roller race 55 is disposed between two outer roller races 56 that are longitudinally spaced along the stub shaft 21. The center roller race 55 is mounted so as to be aligned with the fixed centering point 47 which is the center self-centering point of the stub shaft 21 and is curved about the fixed centering point 47 which is the central self-centering point. It has a double row drum running on the outer track surface 57 of the outer roller track. Outer roller races 5 arranged at both ends in the longitudinal direction of the central roller race 55
6 is an outer raceway surface 5 of the outer roller raceway curved around a fixed centering point 47 which is a center self-centering point of the stub shaft 21.
8 running on a single-row drum. In this configuration, the three roller races 55, 56, 56 together form a complex self-centering bearing assembly, which secures the stub shaft 21 in the longitudinal direction, but the angular Swing is allowed.

The bearing assembly shown in FIG. 3 allows the longitudinal position of the rollers to be adjusted on the first assembly.
The position adjusting means of the outer housing member 53 with respect to the bearing housing 54 is also incorporated. The outside of the outer housing member 53 projects into the inner passage of the bearing housing 54 to leave a small gap 59, and the worm drive mechanism 61 acts between the bearing housing 54 and the outer housing member 53, and The relative positioning of the outer housing member 53 can be adjusted. Fixing bolt 60 as fixing means
Is provided, and the outer housing member 53 after the position adjustment is firmly fixed. To change the setting, the fixing bolt 60 is retracted to allow the adjusting movement between the bearing housing 54 and the bearing, and after the adjustment, the fixing bolt 60 is tightened again. This adjustment allows the longitudinal setting of the roll to be adjusted in the initial assembly. Such adjusting means can be provided in the self-aligning bearing of both rolls, but only one of the rolls needs to be adjusted to achieve longitudinal relative alignment of the rolls. Thus, only one of the roller bearings 41 needs to have an adjusting function, and the outer race member of the other bearing need only be locked to the corresponding bearing housing.

As shown in FIG. 4, the roller bearing 42 includes an inner race member 62 fixed to the corresponding shaft forming portion 22 and an outer race member 63 fixed to the corresponding bearing support 64.
And the inner race member 6 so as to rotate inside the outer race member 63.
2 are flat cylindrical roller bearings each comprising a set of cylindrical rollers 65 adapted to permit movement of the inner race member 62 in the longitudinal direction of the axis of rotation.

For this reason, the position of the stub shaft 21 at one end of the roll assembly is fixed, and the longitudinal expansion of the roll is received by the longitudinal movement of the non-fixed end side, so that the roller bearing 4
2 to produce movement of the stub shaft 22. The bending force acting on the roll due to the thermal expansion effect can be accepted by the self-alignment characteristic of the roller bearing 41 that allows the stub shaft 21 to swing angularly.
Therefore, permanent deformation of the stub shaft 22 due to such bending force is minimized.

The twin-roll casting apparatus of the present invention and the bearing apparatus used in the apparatus are not limited to the above-described embodiment, and various changes can be made without departing from the gist of the present invention. Of course.

[0025]

As described above, according to the present invention,
Since the bending force acting on the casting roll due to the thermal expansion effect is accepted by the self-alignment characteristics of the bearing that allows the shaft to swing angularly, it has the excellent effect of minimizing the permanent deformation of the shaft due to the bending force. obtain.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a strip casting apparatus constituted according to the present invention.

2 is a sectional view of one of the casting rolls of the casting apparatus shown in FIG.

FIG. 3 is an enlarged sectional view of a bearing device which is a roller bearing at one end of the casting roll shown in FIG. 2;

4 is an enlarged sectional view of a roller bearing at the other end of the casting roll shown in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Casting roll 2 Roll gap 5 Metal supply nozzle 6 Casting reservoir 10 Definition wall 11 Solidified strip 21 Stub shaft (shaft forming portion) 22 Stub shaft (shaft forming portion) 41 Bearing 42 Bearing 43 Chock (Bearing support) 47 Centering point (Central region) 51 Inner sleeve 53 Outer housing member 55 Central roller race 56 Outer roller race 57 Outer raceway surface (outer roller raceway) 60 Fixing bolt (locking means) 61 Worm drive mechanism 62 Inner race member 63 Outer race member 64 Bearing support 65 cylindrical roller

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Heiji Kato 2-36-2 Nobi, Yokosuka City, Kanagawa Prefecture (72) Inventor Wayne Russell Australia 2522 New South Wales North Wollongong Zips Street 22 Unit 13

Claims (8)

[Claims] A pair of casting rolls (1) forming a roll gap (2) between them, and a molten metal is supplied to a roll gap (2) between the casting rolls (1) to supply the molten metal above the roll gap (2). Casting pool for molten metal supported on roll casting surface (6)
Supply nozzle (5) for forming a roll and a casting roll (1)
And a pair of reservoir defining walls (10) which are engaged with both ends of the roll to define a casting reservoir (6) at the end of the roll gap (2), and the casting roll (1) is driven to rotate in the mutual direction to roll. Gap (2)
In a twin-roll casting apparatus configured in combination with a roll driving means for producing a solidified strip of metal (11) fed downward from the casting roll (1), a pair of rotating bearings (41) (42) are used. ), A pair of end shaft forming portions rotatably mounted in the roller assembly, and a bearing (41) at one end of the roll assembly positively engages a central region (47) of the shaft forming portion (21) at one end of the roll. Positioning, but allowing the shaft formations (21) to pivot angularly about the central area (47), and the bearing (42) at the other end of the roll assembly being a shaft formation ( 22) A twin roll casting apparatus characterized by allowing the longitudinal movement of 22). 2. A bearing (42) at the other end of the roll assembly.
The inner race member (62) fixed to the corresponding shaft forming portion (22), the outer race member (63) fixed to the bearing support (64), and the inner race member (63) rotating inside the outer race member (63). Flat cylindrical roller bearings each comprising a race member (62) but with a set of cylindrical rollers (65) adapted to allow movement of the inner race member (62) in the longitudinal direction of the axis of rotation. The twin roll casting apparatus according to claim 1, wherein 3. An inner sleeve (51) fixed to a corresponding shaft forming part (21), an outer housing member (53) fixed to a bearing support (43), each bearing (41) at one end of the roll assembly; A bearing device comprising a roller bearing comprising a plurality of rollers disposed between and engaged with an inner sleeve (51) and an outer housing member (53). 4. An inner sleeve (51) and an outer housing member (53) define a plurality of individual roller races spaced longitudinally of a corresponding shaft forming portion (21), each of which comprises:
The center area (47) of the shaft forming portion (21) has the outer roller tracks (57) and (58) formed in a centered curve so that the center area (47) of the shaft forming portion (21) is centered. The bearing device according to claim 3, wherein the outer housing member (53) is allowed to rotate. 5. A central area (47) of the shaft forming part (21) juxtaposed with a pair of outer roller races (56) spaced on each side of the central area (47) of the shaft forming part (21). 5. The bearing device according to claim 4, wherein a central roller race (55) is provided. 6. The roll assembly as claimed in claim 3, wherein at least one of the bearings at one end is provided with adjusting means operable to adjust the longitudinal positioning of the supporting shank formation. A bearing device according to any one of the above. 7. The adjusting means comprises a corresponding bearing support (4).
An adjusting mechanism operable to move the one bearing (41) in 3) and a bearing (4) against a bearing support (43).
7. A bearing device according to claim 6, comprising locking means (60) for locking 1). 8. The bearing device according to claim 7, wherein the adjusting mechanism is a worm drive mechanism (61) acting between the one bearing (41) and the corresponding bearing support (43).