JPS6216248B2 - - Google Patents

Description

Detailed Description of the Invention Technical Field The technical content described in this specification regarding a method for renewing the life of a converter support bearing is a large spherical roller bearing assembly (hereinafter simply a bearing) that supports a converter body trunnion. It is a development result aimed at extending the life of the assembly (called an assembly), and belongs to the field of technology that includes converter repair.

BACKGROUND TECHNOLOGY A converter supports the weight of the furnace and the weight of the charges on a trunnion protruding from a trunnion ring fixed to the circumference of the furnace body, and tilts around the trunnion at each stage of refining operation. During this time, the thermal load is large, so as the trunnion is used,
It is unavoidable that deformation that tilts with respect to the rotational axis progresses over time.

Therefore, the above-mentioned self-aligning roller bearing is used as a bearing assembly in order to smoothly ensure the necessary tilting operation of the converter furnace body regardless of the tilting deformation of the trunnion.

Figures 1a and 1b show an example of the converter body support and its tilting operation system, in which 1 is the furnace body, 2 is the trunnion ring attached to the body circumference, 3 is the trunnion, and 4 is the bearing assembly. It is the body.

The trunnion 3 on one side includes a gear 5, a pair of pinions 6 that mesh with this, an intermediate shaft 7, and a flexible joint 8.
The tilting motion of the furnace body 1 is guided by rotationally driving an electric motor 10 through a reduction gear 9 and a two-part plummer block (hereinafter simply referred to as a bearing box) incorporating a bearing assembly 4. )
are each supported on a bearing stand 12, and the non-drive side bearing box 11 absorbs thermal expansion of the furnace body 1 in the trunnion direction, especially by means of a ladder bearing 13 provided on the bearing stand 12.

For example, in a converter with a furnace capacity of 250 tons, the weight of the furnace reaches 750 tons. The gap with the furnace body 1 is also narrow, reaching 8 m.

Conventionally, when the bearing assembly 4 goes out of order, the intermediate shaft 7 is removed from the flexible joint 8, the gear 5 is pulled out from the trunnion 3, and then the bearing box 11 is removed.
is disassembled and the bearing assembly 4 is replaced.
This required a long period of time, lasting approximately 50 days, and necessitated a significant drop in the operating efficiency of the converter.

The beginning of the idea By the way, converters are tilted during charging and tapping, but the rotation speed of the trunnion on the bearing assembly is slow, and the angular range of the tilt is limited to just over 180 degrees. Therefore, the load on the bearing assembly is concentrated on the lower half of the circumference.

The bearing assembly mainly consists of a plurality of rolling rollers that roll on the outer periphery on an inner raceway that is fitted into a trunnion, and an outer raceway that has a spherical inner surface that guides these rolling rollers. It rotates together with the trunnion 2, and the outer ring raceway is fixed in the bearing box.

Therefore, with approximately 180° of tilting of the trunnion, the entire load of the furnace weight is supported by the rolling rollers arrayed approximately along the lower half of the bearing assembly, while the rolling rollers on the upper half receive most of the load. Therefore, damage or wear of the bearing assembly mainly occurs concentratedly on the rolling rollers located in the lower half circumference and the outer ring raceway in the lower half circumference. Therefore, we focused on effectively extending the life of the bearing assembly by utilizing parts that receive little load during operation.

Purpose of the Invention The present invention is directed to the use of a bearing assembly that supports a furnace trunnion in accordance with the actual state of damage to the outer ring raceway and/or rolling rollers of the bearing assembly under usage conditions specific to the converter. The purpose is to advantageously and easily extend the life of the bearing assembly, halve the number of large-scale bearing assembly replacement operations required in the past, and improve the operating rate of the converter.

Structure of the Invention The above object can be advantageously fulfilled by a procedure which consists of the following matters.

Upper bearing box and bearing used to prevent the outer ring raceway and/or rolling rollers of the spherical roller bearing assembly that supports the furnace body trunnion of the converter from becoming worn out or damaged. With the end plate removed and housed in the lower bearing box, the furnace body is slightly jacked up to restrain its movement, thereby supporting the weight of the furnace, and then moving it together with the rolling rollers of the outer ring raceway. After forcing the idling and moving the damaged parts to a position corresponding to the upper bearing box that is inactive in terms of supporting the weight of the reactor, the above-mentioned shoulder support is released and the bearing assembly is reassembled. A method for renewing the life of a converter support bearing.

In other words, in this invention, the upper half of the bearing assembly, which supports the load of the furnace body, has a relatively low chance of being damaged in the initial stage installation state, and the lower half of the circumference, which is subjected to a much greater load, , by alternately operating the bearing assembly in a half-position, it is possible to advantageously extend the service life of the converter support bearing assembly.

When replacing the moving parts of the bearing assembly, the weight of the furnace is extremely large and the bearing assembly is also huge, so the following arrangements must be made carefully.

First, FIGS. 2a and 2b show a side surface and cross section of the bearing box 11, and FIG. 2c shows a detailed cross section of the main parts. As can be clearly seen in FIG. 2c, the bearing assembly 4 in the bearing box 11 includes an outer raceway 4a, an inner raceway 4b fitted to the trunnion 3, and a plurality of rolling rollers that roll along both raceways 4a, 4b. 4c and a retainer 4c' that holds these rolling rollers 4c, which ensures the retention and fixation of the outer ring raceway 4a within the bearing box 11 and protects the bearing assembly 4 from the severe dust environment near the converter. A ring-shaped cartridge 4d is installed around the outer circumference of the outer ring raceway 4a to provide a firm attachment of a dust seal to protect the outer ring raceway 4a.
are fitted together.

This cartridge 4d has a plurality of horizontal holes 4d' equally spaced on its circumference, and a pair of left and right end plates 4f that sandwich an outer raceway 4d are screwed to both ends of mounting bolts 4e passing through these. , each end plate 4f covers a ring spacer 4g that suppresses the inner ring raceway 4b, and connects a seal link 4h with a seal lip that contacts the outer peripheral surface of the ring spacer 4g to the suppressing ring 4.
Fix with screws i.

As mentioned above, the bearing box 11 is divided into two parts, and the cartridge 4d is placed in the lower bearing box 11a fixedly mounted on the bearing stand 12, and the upper bearing box 11b is placed over the outer ring raceway 4a, and thus the bearing assembly. 4, both bearing boxes 11
a and 11b are connected by a connector 11c.

As described above, the furnace body 1 of the converter is
It can be tilted around the body and held in the required position for blowing operations, but during periodic inspections after repeated operations, smooth tilting movement may be obstructed or repairs may be required due to malfunctions. Instead of replacing the bearing assembly 4, which would take approximately 50 days as in the past,
In this invention, the rolling rollers 4c and the upper half outer ring raceway 4a in the upper half circumference area, which were not actually receiving the load of the converter during the use up to the above inspection, are moved to the lower half circumference area. It operates to support the load.

Here, support for the furnace body load is required.

Therefore, first, remove the retainer 11c of the bearing box 11 and remove the upper bearing box 11b, then loosen the screws of the end plate 4f to the cartridge 4d and remove it together with the mounting bolt 4e.

Here, the end plates 4f on both the furnace body sides and the drive side may be temporarily placed on the outer periphery of the trunnion 3.

In this way, the outer ring raceway 4a is connected to the cartridge 4.
It is held together with d in the lower bearing box 11a to prepare for the following lever jack up.

Next, the furnace body 1 of the converter is jacked up in order to guide the deflection of the outer ring raceway 4a and/or rollers 4c, which have been damaged or worn out due to a significant load mainly in the lower half of the bearing assembly 4. , thereby supporting the weight of the furnace body 1 instead. In addition,
This jack-up also prevents the furnace body from moving.

This jack-up can be done by fixing the flexible shaft coupling 8 that connects the reducer 9 and the gear device 5 shown in FIGS. It would be desirable to make it unnecessary.

Under the minimum necessary jack up, the radial clearance of the cartridge 4d with respect to the lower bearing box 11a cannot be made sufficiently large, and on the other hand, it is natural that an excessive jack up is accompanied by danger, especially the bearing box 11 on the non-drive side. Considering that it can move laterally on the rudder bearing 13, the cartridge 4d
It is necessary to prevent the furnace body 1 from moving inadvertently due to jack-up while keeping the furnace body 1 housed in the lower bearing box 11a, and to prevent a situation of uneven contact.

Therefore, as shown in FIGS. 1a and 1b again, prior to jacking up, a pair of braces 14 sandwiching the trunnion 3 between the non-drive side bearing stand 12 and the furnace body 1 are welded and fixed to the bearing stand 12. Furnace body 1
Fix it by driving a wedge between it and the iron skin.

Next, in order to prevent the furnace body from moving in a direction perpendicular to the trunnion 3, a second strut 16 is installed between the main beam 15 on the floor of the converter yard and the furnace body 1 as shown in FIGS. 1a and 1c. The jack stands are welded and fixed to, for example, the floor beam 15 as a pair of front and rear jacks sandwiching the trunnion 3 of the furnace body 1, and a hydraulic jack 17 with a capacity of about 50 tons, for example, is placed between the furnace body 1 and the strut 16. do.

As described above, the hydraulic jack 17 is provided with an adjustment function in case a collision occurs between the cartridge 4d and the lower bearing box 11a, as well as a rotation prevention function of the furnace body 1.

In the above manner, the movement of the furnace body 1 can be prevented.

Next, under the restraint of blind movement of the reactor body, a slight jack is used to shoulder and support the weight of the reactor. Strength struts 19 are applied to the underside of the trunnion ring 2, also at the front and rear sides of the trunnion, as shown in FIGS. 1a and 1b.

For example, each hydraulic jack 18 has a capacity of 200
It is preferable that there are 2 units of 100 ton units for a total of 4 units, each of which can be individually adjusted in stroke.

For the pillars 19, two dedicated built-up ones made of shaped steel or steel plates are used, and one of the pillars 19 is used as shown in the figure.
It is convenient to set up two hydraulic jacks 18 per book.

The balance between the jack up and the resulting left and right radial clearances can be checked using the dial cage 20 as shown in Figure 3. Fine adjustments to the jack up dimensions can be made by the dial gauge checker on the second floor and the hydraulic jack on the ground. Eighteen operators communicate closely using transceivers and other equipment.

As a result, the weight of the furnace is supported by the supports 19 by being jacked up.

Next, as shown in the figure, the damaged parts of the outer ring raceway 4a and rolling rollers 4c are moved together with the cartridge 4d to a position corresponding to the upper bearing box 11b, which becomes virtually inoperable in supporting the furnace weight. The rolling rollers 4c are placed in the lower bearing box 11a.
The inner raceway 4b is rotated within the inner ring raceway 4b.

At this time, the horizontal hole 4d' of the cartridge 4d is used.

That is, a hydraulic jack is installed on the lower bearing box 11a by applying, for example, a hanging cable 22 to the horizontal bar 21 that passes through the horizontal hole 4d' and projects at both ends, and using a chain block 23 to lock a lever 24 to the horizontal bar 21. By applying 25, the cartridge 4d
This forces the wheel to idle along with the outer ring raceway 4a.
A chain block 23 with a capacity of about 5 tons and a hydraulic jack with a capacity of about 25 tons are suitable here.

In order to prevent damage or wear and tear on the outer ring raceway 4a, it is sufficient to rotate the outer ring raceway 4a together with the cartridge 4d over approximately half the circumference.On the other hand, as for the rolling rollers, the cartridge should be rotated in the same way depending on the position so that the rollers reach the upper half circumference. At 4d, perform the above idle rotation.

At this point, the damaged areas should be confirmed in advance, and the rolling parts should be cleaned to remove foreign matter such as scale and dirt from the inner and outer ring raceways.

That is, for example, using a mixture of turbine oil and Freon solvent, the inner and outer ring raceways 4b, 4a are heated by an air flow.
The lubricant is sprayed between the outer ring raceway 4a and the rolling rollers 4c to remove the residue of the filled lubricant and foreign substances such as scale and dirt. The damaged portion is always located only in the upper half circumference region corresponding to the bearing box 11b.

After that, the same cleaning as above is carried out again, followed by applying turbine oil to the entire rolling part, and then the hydraulic jack 18 is loosened to fit the cartridge 4d tightly into the lower bearing box 11a, and the end plate 4f and the seal are removed. After reassembling the ring 4h, the upper bearing box 11b is retightened.

At this time, the cartridge 4d and the end plate 4 are used for drilling a locking pin in the bearing box 11 of the cartridge 4d and for supplying oil to the bearing assembly 4 through the upper bearing box 11b.
Needless to say, it is necessary to process the oil holes f.

1a and b, drive side bearing assembly 4
Although we have explained the repair procedure according to this invention for the non-drive side, the non-drive side can also be repaired using almost the same procedure as described above, and the total work schedule is as follows for a furnace with a capacity of 250 tons almost 5
It was about a day warm.

Effects of the Invention This invention provides that the bearing assembly that supports the furnace body trunnion of a converter does not necessarily require complete replacement when it goes out of order due to the specificity of the load that occurs on its outer ring raceway and rolling rollers. Based on the new idea of At least double the service life of the bearing assembly by reassembling it in a position corresponding to the upper bearing box, which is effectively out of service;
Repairs can be performed much more easily than in the conventional case of replacing the bearing assembly with a new one.

[Brief explanation of the drawing]

Figures 1a, b, and c are a plan view, a front view and a side view with main parts cut away, of the tilting operation system of the converter;
Figures 2a, b, and c are a side view, a sectional view, and a detailed view of the main parts of the bearing assembly, and Figure 3 is an explanatory diagram of the construction procedure for forcing the outer ring raceway of the bearing assembly according to the present invention to idle. It is. DESCRIPTION OF SYMBOLS 1... Furnace body, 3... Furnace body trunnion, 4... Bearing assembly, 4a... Outer ring raceway, 4c... Rolling roller, 4e...
Bearing end plate, 11a...lower bearing box, 11
b...Upper bearing box.

Claims (1)

[Scope of Claims] 1. When the outer ring raceway and/or rolling rollers of the spherical roller bearing assembly supporting the furnace body trunnion of the converter become worn out or damaged, the outer ring raceway is used to prevent the wear and tear. The upper bearing box and bearing end plate provided were removed and placed in the lower bearing box, and the furnace body was slightly jacked up under the restraint of its movement, thereby supporting the weight of the furnace, and then the outer ring was After forcing the raceway to idle along with the rolling rollers and moving the damaged parts to a position corresponding to the upper bearing box that is inactive in supporting the weight of the furnace, the shoulder support is released and the bearing is assembled. A method for extending the life of a converter support bearing, comprising: reassembling the body.