GB2107624A - Casting installation with a plurality of melt vessels - Google Patents

Abstract

The melt vessels, such as steel melt ladles (2) are each selectively movable to a casting station and each includes a sliding gate valve (10) connected to a reduction gear (11). Each reduction gear (11) is connected on its input side to a first rotary coupling member (12) and the installation further includes a single rotary drive unit (20) connected to an extensible universal- jointed shaft (22) which in turn is connected to a second rotary coupling member (24). The coupling member (24) is readily releasably securable to any one of the coupling members (12) and thus the single motor can operate all the sliding gate valves one after the other. Where the melt vessels always adopt substantially the same casting position, the drive unit (20) may be fixedly mounted at the casting station (Fig. 1) or, where the vessels are moved successively into different casting positions, supported by the melt vessel (Fig. 2). <IMAGE>

Description

SPECIFICATION Casting installation with a plurality of melt vessels The invention relates to a casting installation of the type including a plurality of melt vessels, each of which is selectively movable to a casting station and includes a sliding gate valve and is concerned with the operation of the said sliding gate valves.

In installations of this type it is conventional to provide an individual drive motor and a reduction gear for each sliding gate valve and to mount it fixedly on the melt vessel as the gate valve itself. This (in contrast to actuation of the gate valve by means of a removable hydraulic cylinder) is considered to be necessary in order to ensure an unimpeded mechanical force transmission between the motor and the gate valve via the gear members.

However, in comparison to hydraulic actuation, this requires a considerably increased expense and the relatively delicate motor is always subject to very demanding operating conditions, not only at the casting station but also during transport of the melt vessel which may be a steel casting ladle or an intermediate vessel of a continuous casting installation.

It is the primary object of the present invention to provide a more economical means for actuating the sliding gate valves on the melt vessels of a casting installation.

According to the present invention there is provided a casting installation including a plurality of melt vessels each of which is selectively movable to a casting station and includes a sliding gate valve connected to a reduction gear, each reduction gear being connected to its input side to a first rotary coupling member, the installation further including a single rotary drive unit connected to an extensible universal-jointed shaft and a second rotary coupling member which is readily releasably securable to any one of the first rotary coupling members.

In the installation in accordance with the invention, the single drive unit present at the casting station can actuate the sliding gate valve of as many melt vessels as is required one after the other. Unavoidable differences in positioning and in the dimensions of the individual vessels are compensated for by the universal-jointed extensible shaft and the latter together with the second rotary coupling member have only a small torque to transfer to the drive side of the speed reduction gear.

This ensures that the reaction forces between the drive unit and the vessel, which is generally freely suspended, also remain small.

In one embodiment of the invention the rotary drive unit is fixedly mounted at the casting station. It can then be accommodated at a protected position and the energy supply, e.g. an electrical or hydraulic lead, can also be permanently installed. In this manner maintenance is simplified and operational security increased. Alternatively, when the installation includes a plurality of casting ladles which are to be moved into different casting positions whilst suspended from a crane, e.g.

when ingot casting the rotary drive unit may be readily releasably securable to any one of the melt vessels when in the casting position so as to be supported thereby. In addition to a main motor, the drive unit preferably also includes a standby or emergency motor. The reduction gear mounted on each melt vessel must not of necessity be constructed to effect the entire speed reduction, and thus a speed reduction gear which effects part of the speed reduction between the drive unit and the sliding gate valve can be provided on the rotary drive unit.

The invention is applicable to all motor driven types of sliding gate valve, that is to say particularly rotary sliding gate valves but also pivotal sliding gate valves and, with an appropriate construction of the reduction gear, linear sliding gate valves. In this connection it is also possible that different types of gate valve variously connected to the melt vessels of the installation may be operated by one and the same drive unit.

Three specific embodiments of the invention will now be described in more detail with reference to the accompanying diagrammatic drawings, in which: Figure 1 is a side view of the casting station, of e.g. a continuous casting installation with a drive unit fixedly mounted on a ladle truck; Figure 2 is a perspective view of a construction with a drive unit connected to a casting ladle; and Figure 3 is a detailed scrap underplan view of the connection between a universal-jointed shaft and a reduction gear in conjunction with a linear sliding gate valve.

Fig. 1 shows a casting truck 1 situated at the casting station of a casting installation and supporting one casting ladle 2 of a plurality of such ladles supported on the truck in a known manner by means of side bars 3. Beneath the casting ladle there is an intermediate vessel 5 (tundish), into which the melt is discharged from the ladle 2. A sliding gate valve 10, in this case a rotary sliding gate valve, is mounted on the base of the ladle to regulate the melt discharge, and a reduction gear 11 is also mounted on the ladle 2 to actuate the valve 10.

At a suitable position on the casting station, in this case on a cantilever 4 projecting from the casting truck 1, a rotary drive unit generally designated 20 is fixedly mounted. This includes a drive motor 21 and a telescopically extensible universal-jointed shaft 22 which is provided at its end with a rapid coupling 24.

The gear 11 has a stub shaft 1 2 on its input side for rotary connection with the rapid coupling 24.

The rotary drive unit 20 whith the telescopic universal-jointed shaft 22 and rapid coupling 24 are thus part of the casting station equipment, whilst each casting ladle 2 intended at some time to be moved to this casting station is provided with a sliding gate vale 10 and an associated reduction gear 11.

The drive connection between the motor 21 and the sliding gate valve 1 0 on the casting ladle at the casting station is effected by plug connecting the rapid coupling 24 to the stub shaft 12, and when casting is finished the drive connection is separated again in a similar manner. The universal-jointed shaft and the rapid coupling are of a construction known per se and can be constructed relatively lightly because only a relatively small torque is to be transmitted to the input side of the reduction gear. By virtue of the extensible universal-jointed shaft, the precixe positioning of the casting ladle 2 on the ladle truck 1 with respect to the casting station is not critical.

With this construction the motor 21 can easily be accommodated at a protected position where it is much less subject to heat radiation. In this manner the expense of maintenance is considerably reduced and the operational security increased. In addition to the main motor 21 an emergency or standby motor 21' can, as shown, be provided, e.g.

an electric motor as main motor can be combined with a hydraulic motor as emergency motor.

If the intermediate vessel 5 is also provided with a bottom gate valve for the regulation of the discharge, the same drive arrangement can in principle also be provided for this valve. A bottom gate valve 10' with a reduction gear 11' and a rotary coupling portion 1 2' on the input side are shown in Fig. 1 in chain dotted lines on the intermediate vessel 5. The associated rotary drive unit (not shown), which is part of the equipment of the casting station, can then be mounted, for instance fixedly or on the tundish truck. The production and release of the drive connection between the drive unit and the reduction gear 11' when exchanging the intermediate vessel occurs in the same manner as described above in conjunction with the casting ladle 2 by means of the rotary coupling portion 12' and the associated rapid coupling.

A fixed arrangement of the drive unit at the casting station is possible if the melt vessels always adopt substantially the same casting position. If, on the other hand, as is common when casting into ingot moulds, casting ladles are moved succesively into different casting positions whilst supported on the casting crane, an arrangement as shown in Fig. 2 is appropriate. The rotary drive unit generally designated 30 is connected in an easily releasable manner to a casting ladle 2 of several such ladles by plug connecting it to appropriate side bars on the ladle shell by means of pintles 35 by using an auxiliary crane to engage the eyes 34.The casting ladle 2 shown in the casting position over an ingot mould 6 is again equipped with a bottom gate valve 10, e.g. a rotary gate valve, and an associated reduction gear 1 3. The rotary drive unit 30 includes a motor 31 mounted on a support 33 and an extensible universal-jointed shaft 22 provided with a rapid coupling 24.

When the unit 30 is secured to the ladle 2 the rapid coupling 24 can be easily coupled to and uncoupled from the stub shaft 14 of the gear 1 3. As shown in Fig. 2, a partial speed reduction can be provided between the motor 31 and the shaft 22, as here in the form of a spur gear 32, so that the gear 1 3 on the ladle thus does not perform the entire rotary speed rotation. Of importance is that the torque transmitted between the coupling members 24 and 1 4 is still relatively small, compared to the torque necessary at the gate valve 10, whereby the reaction forces which load the releasable connection between the drive unit and the casting ladle, i.e. the plug connection 35, also remain small. When the ladle 2 is empty, the drive unit 30 is disconnected from it and connected to a fresh ladle and casting continues.

Fig. 3 is a scrap view on a larger scale of an embodiment of the invention incorporating a linear sliding gate valve; the components forming part of the equipment of the melt vessel but only the end of the extensible universal-jointed shaft 22 with its universal joint 23 and plug coupling 24 of the drive unit associated with the casting station are illustrated. The schematically illustrating sliding gate valve 10" is secured to the base of the casting ladle 2. The associated speed reduction gear 1 5 includes a threaded spindle 18 of which one end is splined and radially and axially located in a bearing 17. The other end of the spindle 1 8 is in engagement with a threaded hollow bush 1 9 which is connected to the slider of the gate valve 10" and moves the latter linearly when the threaded spindle 18 is rotated. A coupling box 24 on the universal joint 23 is plug connected to the shaft end 1 6 in a manner known per se and secured, e.g. by means of a tangential pin and thereby constitutes a releasible rotary drive connection. Thus this embodiment also permits the actuation of the bottom gate valve of a plurality of melt vessels when in the casting position by means of a single drive motor associated with the casting station. It is thus not necessary to equip each vessel with a motor, such as an electric motor, and furthermore the relatively delicate motor at the casting station can be accommodated at a position in which it is substantially better protected than it would be on the casting vessel itself.

By virtue of the extensible universal-jointed shaft, which in the installations described above effects the connection between the casting station equipment and the respective melt vessel, a precise positioning of the latter at the casting station is not essential and horizontal and vertical positional deviations and also slight oscillatory movements can be compensated for without difficulty. The melt vessel can also be moved away without delay from the casting station in an emergency, even without previously releasing the rapid coupling 24. In this event the inner shaft of the universal-jointed shaft 22 is pulled out of its hollow outer shaft and remains hanging and each component remains hanging on the relevant universal joint.

Claims (6)

1. A casting installation including a plurality of melt vessels each of which is selectively movable to a casting station and includes a sliding gate valve connected to a reduction gear, each reduction gear being connected on its upper side to a first rotary coupling member, the installation further including a single rotary drive unit connected to an extensible universal-jointed shaft and a second rotary coupling member which is readily releasably securable to any one of the first rotary coupling members.

2. An installation as claimed in Claim 1 in which the rotary drive unit at the casting station is fixedly mounted.

3. An installation as claimed in Claim 1, in which the rotary drive unit is readily releasably securable to any one of the melt vessels when in the casting position so as to be supported thereby.

4. An installation as claimed in one of the preceding claims in which the rotary drive unit includes a main motor and a standby motor.

5. An installation as claimed in any one of the preceding claims in which a reduction gear is arranged between the drive unit and the universal-jointed shaft.

6. A casting installation substantially as specifically herein described with reference to any one of the accompanying drawings.